Perfomance Expectations

[JRL]

Using the typical performance measurements what do you expect.

HP
Weight
0 - 60
0 - 100
1/4 Mile
Top Speed
70 - 0 Braking
Lateral G's
MPG

Cost for you to meet your expectations.

[Kalstar]

HP 250
Weight <2000
0 - 60 <4.3sec
0 - 100 <9sec
1/4 Mile 12.0- 12.5
Top Speed 150mph
70 - 0 Braking 140ft
Lateral G's >1.00
MPG who cares.....20ish??
Cost....Sub 18K

[PhyrraM]

HP: Enough to clench, but not pinch. (Stock WRX with a tune for 818 exhaust should do it)
Weight: As little as possible
0 - 60: Faster than anything I've ever driven before.
0 - 100: Faster than anything my friends have ever driven before.
1/4 Mile: Fast enough that I have to fight the urge to lift.
Top Speed: Not likely to ever find out, but surely it can redline in top gear.
70 - 0 Braking: Quickly enough to make seatbelts manditory, again and again...right up to the threats of divorce from the passenger.
Lateral G's: Enough to make any drink, in any container, a sticky mess.
MPG: No care. 250+ mile range.

Cost for you to meet your expectations. With any luck - $9900 + Shipping + tires + DMV + garage full of Subaru parts.

[DrieStone]

HP 250
Weight <2000
0 - 60 <4.3sec
0 - 100 <9sec
1/4 Mile 12.0- 12.5
Top Speed 150mph
70 - 0 Braking 140ft
Lateral G's >1.00
MPG who cares.....20ish??
Cost....Sub 18K

I'd agree with pretty much all of this, although my expectation of Top Speed for the non-race version would be more around 135-140MPH and 1/4 mile probably 12.5-13.0 seconds.

I really don't care about top speed or 1/4 mile for the most part. I care about the 10-100MPH and lateral G's.

[Silvertop]

HP: Enough to clench, but not pinch. (Stock WRX with a tune for 818 exhaust should do it)
Weight: As little as possible
0 - 60: Faster than anything I've ever driven before.
0 - 100: Faster than anything my friends have ever driven before.
1/4 Mile: Fast enough that I have to fight the urge to lift.
Top Speed: Not likely to ever find out, but surely it can redline in top gear.
70 - 0 Braking: Quickly enough to make seatbelts manditory, again and again...right up to the threats of divorce from the passenger.
Lateral G's: Enough to make any drink, in any container, a sticky mess.
MPG: No care. 250+ mile range.

Cost for you to meet your expectations. With any luck - $9900 + Shipping + tires + DMV + garage full of Subaru parts.

I like the way you think. :)

[Draco-REX]

My plan is for an easy 400 crank hp build. With my big bulk in the seat the internet calculators are giving me sub-3sec 0-60 times and mid-10sec 1/4 mi times. I doubt that, personally, and would be happy with 0-60 in the low 4s and 1/4mi times in the low 12s, high 11s. If it DOES do those times above, I'll be amazed and probably be stricken with perma-grin for a few days. ;)

[Oppenheimer]

~250 HP
~1800 lbs Weight
<4.5 sec 0 - 60
not important 0 - 100
not important 1/4 Mile
not important Top Speed
<140 ft 70 - 0 Braking
~.9 Lateral G's
30+ hwy MPG

I plan to drive the car, a lot. As in all the time. All the time its not pouring rain or icey roads, and I don't need to carry a lot of stuff or people. So MPG is important. Not as important as performance, but at this PW ratio, I know all the performance I want will be there. Am I good candidate for the TDi drivetrain? Perhaps, but I'll probably go with WRX. All the power I could want and more easily obtainable, still likely to get decent MPG when I'm not heavy on the pedal.

[vozproto]

HP: Enough to clench, but not pinch. (Stock WRX with a tune for 818 exhaust should do it)
Weight: As little as possible
0 - 60: Faster than anything I've ever driven before.
0 - 100: Faster than anything my friends have ever driven before.
1/4 Mile: Fast enough that I have to fight the urge to lift.
Top Speed: Not likely to ever find out, but surely it can redline in top gear.
70 - 0 Braking: Quickly enough to make seatbelts manditory, again and again...right up to the threats of divorce from the passenger.
Lateral G's: Enough to make any drink, in any container, a sticky mess.
MPG: No care. 250+ mile range.

Cost for you to meet your expectations. With any luck - $9900 + Shipping + tires + DMV + garage full of Subaru parts.

Hahahaha. Very nice.

This should be posted on the window sticker for specifications.
So much more exciting than the standard window sticker on today's cars.

[Xusia]

HP: Expecting about 300 with an 08 STi engine mated to the 5mt
Weight: FFR states 1800 lbs.
0 - 60: My requirement is <5 secs, but I expect this car to be around 4 secs, maybe less.
0 - 100: I don't really care, as I'm not likely to exceed 100mph (it will be a daily driver that probably won't see any track time - we'll see!).
1/4 Mile: I don't race, so I'm unlikely to know for sure, but base on specs it should be <12 secs.
Top Speed: Don't really care at all; will prob depend on gearing. It will have the power-to-wait ratio to reach 150+ (with gearing that allows for that).
70 - 0 Braking: 125 feet.
Lateral G's: 1.05 - 1.10. Supposedly, this will be their best handling car, and I believe the Daytona Coupe is good for 1.05, so this car should do better.
MPG: Literally ANYTHING will be better than the 13 mpg my truck gets now.

I'm budgeting $20k (which I believe is totally plausible), though I'm trying to keep costs to as little as possible.

[skullandbones]

Go to the FFR performance chart and make it first place in every column including against the Enzo! And that includes the price, of course. No problem there. WEK.

[Evan78]

As a point of comparison, here are results from Edmunds on a 2007 Lotus Exige S (http://www.insideline.com/lotus/exige/2007/follow-up-test-2007-lotus-exige-s.html) that had a supercharged 1.8L rated at 220hp/165tq and weighs 2050 lbs.

0-60 - 4.2
1/4 - 12.8 @ 105.5

And on the other end of the spectrum is an Edmunds test of an Atom (http://www.insideline.com/ariel/full-test-2005-ariel-atom.html) running a supercharged K20 engine making estimated 375hp/275tq weighing 1350 lbs.

0-60 - 2.8
1/4 - 10.6 @ 128.4

So I would guess sub 4 seconds on 0-60 and low 12's in the quarter using a stock turbo'd 2.0L wrx engine that makes around 275hp.

[DrieStone]

So I would guess sub 4 seconds on 0-60 and low 12's in the quarter using a stock turbo'd 2.0L wrx engine that makes around 275hp.

Not to rehash, but I don't think the prospective donor vehicles are 275hp (that's the 2.5l WRX). Stock WRX donor (2.0l) in the proper model years is 227hp (although with a simple uppipe/downpipe upgrade you should be able to achieve ~260hp).

So based on the Exige S stats I'd say we're looking at about the same targets with the base WRX motor which is what I'd expect. The biggest difference is that the aftermarket is going to be huge compared to the Exige.

[Evan78]

275hp is a realistic crank hp for a 2.0L with the typical turboback exhaust and tune. No non-STi WRX has been factory rated at 275hp. The current model is 265hp. The 2.0L motors will typically do 220-230 whp on the stock TD04 turbo with an exhaust and tune. Typical unmodified power is about 175whp.

I'm no Subaru expert, but I've put around 200k on modified 2.0 and 2.5L Subarus spread over 3 cars.

But that's all off topic, this thread isn't about what stock or modified engines make. The question was what performance do you expect, and naturally HP has a relationship with acceleration numbers.

[thane]

I expect a basic build (stock 2.5l motor and turbo with tune-around 220 whp) to produce Exige like numbers. My concern is that, when you get to the sharp end of car performance, driver ability and the ability of the car to put power to the ground become really variable. To illustrate what I mean, I'll offer the following example: My expectation is that an 818 with the same power to weight ratio of a GTR will struggle to produce the same acceleration numbers as a GTR. We'll see; like everyone else, I'm just conjecturing. That said, I hope to use my '06 wagon to build a car that will reliably put down Exige-like numbers and get around 35 mpg/highway.

thane

[Brian Z]

A roadster with 300hp goes 0-60 in around 3.6 seconds. That's a 2,300lb car...
The 818 will be 1,800lbs with more weight over the rear tires. I'm guessing somewhere around 3.5 or 3.4 seconds to 60 mph.

[Les Edwards]

I drove my go cart enough to realize that I couldn't possibly pay for all the tickets I COULD get. A little scary huh?

[BrandonDrums]

A roadster with 300hp goes 0-60 in around 3.6 seconds. That's a 2,300lb car...
The 818 will be 1,800lbs with more weight over the rear tires. I'm guessing somewhere around 3.5 or 3.4 seconds to 60 mph.

Man that's fast.

My expectations for me are

HP: 300 whp
Weight 1,850 lbs (AC/Heat)
0 - 60 a little less than 4 seconds on average, 3.5 sounds quick but I imagine with good tires and a steady foot it can be done.
0 - 100 quickly
1/4 Mile - in the twelves at least
Top Speed - I think 5th gear maxes out around 180 but with a roadser's COD, I bet we're looking at 160-170
70 - 0 Braking - what's too fast to live through and back it off just a little bit
Lateral G's - 1.00 on streetable summer tires, DOT legal competitions and it could be 1.1+
MPG - for the 2.0L 25 combined, 22 city 29 highway. With a 2.5L 20 city and 27 or 28 highway, gearing really limits the highway numbers, too many revs/mile and at 65-75 in 5th gear your right there at max spoolup range for the stock turbos. However, I could have really low expectations, I really don't know what to expect with that much weight off and 2wd. I just seem to believe the EJ turbo motors suffer more from being EFI turbo engines than being attached to an AWD system, so much fuel is used just to protect the engine which doesn't change when you take weight off of it.

Another performance expectation: I hope and expect to be performing my build in the next 3 years...

[bbjones121]

There is no way that this thing would be anywhere above 3.5 seconds to 60mph with 300whp.
You WILL have trouble with traction at start, but a 1/4mile should be in low to mid 11 seconds.

12's......seriously???

my Legacy (3400+lbs) with 350whp runs a 1/4 in 12.8 at a mile high elevation!

818 about 6.3lbs per hp (about the same as a Pagani Zonda)
my legacy gt 9.7lbs per hp

You can play around with this rough estimate tool I found online.
http://robrobinette.com/et.htm

Granted it won't be as aerodynamic as a Pagani, but I have some faith in FFR to put some thought in the aero.

[kach22i]

Any guess what a cheapskate 170 hp model's performance would be?

0-60 in about 6 seconds?

[PhyrraM]

Any guess what a cheapskate 170 hp model's performance would be?

0-60 in about 6 seconds?

@1800 pounds - likely more like low 5.XX

[Silvertop]

@1800 pounds - likely more like low 5.XX

Which is probably fast enough to get MY pants wet!!!!

[Niburu]

I expect it to go like stink.

[kach22i]

@1800 pounds - likely more like low 5.XX
More than fast enough for me.

As long as I can prevent those soccer moms from trying to drive me off the road, I'm happy.

[apexanimal]

^oh yeah...

i think most of us get happy when talking about a turbo, but the 2.5l n/a is going to make this thing get up and go... it won't be supercar territory, but it'll be quick enough, and handle the same (it'll be minus some weight vs turbo), to embarass quite a few cars out there...

[bbjones121]

^oh yeah...

i think most of us get happy when talking about a turbo, but the 2.5l n/a is going to make this thing get up and go... it won't be supercar territory, but it'll be quick enough, and handle the same (it'll be minus some weight vs turbo), to embarass quite a few cars out there...

Definitely need the turbo out here at a mile high. N/A is terrible up here.

stock n/a engine at sea level should still get you a mid 12 second 1/4 mile, that is faster or as fast as almost any sport car you will see out on the road.

[shinn497]

I have a question.

Say I put a spec C ver 8 EJ207 and tune it to 400 + wtq.. I am not saying this is a good idea but I am just wondering...Wouldn't I need MASSIVE super sticky tires? Since this thing is so light, it does not have as much weight pushing down on the rear tires. How much of a performance limit would this impose.

[Dave Smith]

This is a favorite topic of mine as we get closer to testing the car. I can tell you that Jim and Jesper loathe the idea of predicting times/performance since they are both of the opinion that the car industry is rife with BS artists who claim numbers but never back em up. The numbers we've posted are usually (always) from an independent source. Car and Driver tested the GTM and our claims were modest. The 3.0 number they reached was actually 2.88 seconds corrected for temp/pressure. I don't care since the car actually ran 2.88 sec to 60 sheesh that's very very fast.

With respect to the 818, I think all the essential elements are there and the design charter includes a heavy emphasis on performance in release 1. I will torment Jim and ask him to make an educated guess based on all data available up to now and our real-world experience of our other designs. My guess is that the car will be capable of more than most people will reallly be able to use on a public road. I can't imagine putting a Factory Five badge on any car that doesnt perform.

CORRECTION: The time for the GTM was not corrected upwards as I thought. It was 2006 and the car simply ran 3.00 seconds flat.

[bbjones121]

I have a question.

Say I put a spec C ver 8 EJ207 and tune it to 400 + wtq.. I am not saying this is a good idea but I am just wondering...Wouldn't I need MASSIVE super sticky tires? Since this thing is so light, it does not have as much weight pushing down on the rear tires. How much of a performance limit would this impose.

If you had that much power in the 2 liter, it would be coming at very high revs. Since you wont have the jolt off the line, asuming you want the clutch to last, it may be able to keep a better traction than a 2.5 with that much torque. That sure would be a laggy setup. Lag can be fun if you know how to drive with it.

[Someday I Suppose]

Dave, that right there should be incorporated into the FFR Marketing... How fast is it is probably the question I get the most about the roadster, the answer is I have no idea, fast enough that I can put a smile on my face anytime I want, and fast enough to have a ton of respect for the go pedal.



My guess is that the car will be capable of more than most people will reallly be able to use on a public road. I can't imagine putting a Factory Five badge on any car that doesnt perform.

[skullandbones]

Dave,
Can you give the forum an idea of how the testing process will go? I am curious as to what body will be used. Will it be a prototype like Jim's designed body since it exists already? Are there usually major changes made to the chassis and running gear or have you pretty much perfected the mechanicals of the project? I was hoping you could give some examples based on the history of the other designs by FFR. Thanks, WEK.

[Jim Schenck]

Edited: Thinking about it some more I think it is more important for us (here at FFR) to get the car done and show the real numbers than try and guess what it'll do. Nothing wrong with speculating but being the manufacturer I'd rather to let the real data do the talking.

[MuddyRoverRob]

That should be quick enough to not hold up granny in the buick!

[thestigwins]

Jim, slip us some inside info ;) where are we at in the design process? I will send you a case of beer! your choice!

[mattster03]

As a guy who takes drag racing pretty seriously, I would predict the car's quarter mile to range anywhere from mid-high 11's to mid-high 12's for your average 250whp 818; Completely dependant on tire and driver skill. Put a set of ET streets on there and with practice and provided your drivetrain holds up, welcome to the 11's. If it's your first time out and you use a set of 300 treadwear rating summer tires and you'll be stuck in the mid 12's. Drag tracks are prepped for a specific adheision between heated slicks and the launch area; this prepping often makes trying to hook with street tires even worse than on normal tarmac.

Be careful of those online calculators, you really need to know how to use them... this is why civic drivers often claim they have a "10 second car" right before they go and run a nice solid 13. And don't forget your car doesn't drive itself... add in driver weight.

[apexanimal]

For Dave, and again at gun point, I ran the basic configuration through our simulator using a standard WRX 227hp engine, stock differential (open) and street tires. That shows 0-60 in 4.9 and a 1/4 mile of 13.4

not that i want to hold a gun to your head ;)

vauge estimate with a n/a motor?

[bbjones121]

I would predict the car's quarter mile to range anywhere from mid-high 11's to mid-high 12's for your average 250whp 818;

No matter what the online 1/4 estimators say, that should be in the high 11's. Grab a trusty calculator or use the one on your computer.
250whp@the crank is probably 300hp (obviously you could argue this up or down based on the various dynamometers out there).
That is 6lbs per hp (not including driver...obviously if you are small and skinny, you will be faster than a tall and fat person).

A lotus exige s is 260hp @ 2060lbs, that is 7.9lbs per hp (not including driver), it runs a 12.6sec 1/4 mile
The lotus 2 eleven is 252hp @ 1480lbs, that is 5.8lbs per hp, it runs a 12.2 1/4 mile (now we are getting closer)

With this info alone you could say it should be in the low 12's, but you need to look at the power curves of these engines. The lotus 2zz 1.8l Toyota engine runs a much lower torque than that of the subaru. When you say 250whp on the Subaru engine you can bet you are probably getting more than that in torque, in most cases you will probably have more torque than horsepower. There is going to be a lot more area under the curve with the Subaru engine that should cut a quarter to a half second off the slip time.

Like you said, this is all up to the driver and assuming you don't slip the tires.



provided your drivetrain holds up,

The subaru drive-train would be bulletproof in normal form at that power level, I don't know what the FWD conversion on the thing will do.

[Strang08070]

gota love ppl posting about cars without looking it up. the 2-11 weight just under 2150 pounds wet an has a 189 horse engine.

[bbjones121]

gota love ppl posting about cars without looking it up. the 2-11 weight just under 2150 pounds wet an has a 189 horse engine.

You might want to check your sources. Or if you dont want to, take a look at a a picture of a 2eleven and then look at a picture of an exige. Once you do that, ask yourself if it makes any sense to say a 2 eleven weighs more than an exige like you just did.

[Dave Smith]

Couple of answers here (and btw, Mad Dog and I have HIBERNATED ALL WEEK) working on the new FFR website which inlcudes an updated 818 section.

The final body shape of the first 818 model has been selected and has been fully digitized. It will be a roadster to start with a later soft top for sure and a likely removable hardtop. We will not show the body until we have a driving car. We MAY show the finished CAD model body shape soon if all is good. The project has gone a bit dark and that is a function of us having the data we need and simply wanting to design and build the car as fast as possible without compromising quality or making claims that end up inflated.

Regarding performance though, I do feel that this car will (has to) be on the upper end of what we've done up to now. I can see a 300-350 hp car that weighs 1800 lbs and runs sticky DOT legal tires running easily in the threes (to 60) and 1/4 mile times in the 11's. At the same time I think most people will be BLOWn away with the fun factor (and speed) of a $500 Imprezza donor build even with the torquey little 165 hp mill. Good brakes, suspension and FFR handling should make a smile wrap around your head. I own one of each FFR model and from the work I've seen to date on the 818 I am more anxious to throw this thing around than any other. I can't wait to drive this thing and the variables we are discussing will be better discussed with data.

Jim wants to let the car speak for itself and that is fine. We're close to the new website and perhaps a more detailed (but not EXACT) parts list of Subie parts that will be needed.

The traction issue is a big one, but the crew has a good history with solving those challenges and the car is mid-engined. All I can say is that a spec racer at 2400 lbs and 225 hp/300 lb ft nails 0-60 in 4.5 seconds all day long with toyo prox 888 DOT race tires. I think that accel times will be all over the map. The one thing I am absolutely 100% sure of at this point is that the car will be one of the most entertaining and fun cars to drive on the planet.

[keys2heaven]

Thanks Dave.

Can you or will you tell us if this final body shape is based off of one of the winning designs from the body contest?

[JLee]

Couple of answers here (and btw, Mad Dog and I have HIBERNATED ALL WEEK) working on the new FFR website which inlcudes an updated 818 section.

The final body shape of the first 818 model has been selected and has been fully digitized. It will be a roadster to start with a later soft top for sure and a likely removable hardtop. We will not show the body until we have a driving car. We MAY show the finished CAD model body shape soon if all is good. The project has gone a bit dark and that is a function of us having the data we need and simply wanting to design and build the car as fast as possible without compromising quality or making claims that end up inflated.

Regarding performance though, I do feel that this car will (has to) be on the upper end of what we've done up to now. I can see a 300-350 hp car that weighs 1800 lbs and runs sticky DOT legal tires running easily in the threes (to 60) and 1/4 mile times in the 11's. At the same time I think most people will be BLOWn away with the fun factor (and speed) of a $500 Imprezza donor build even with the torquey little 165 hp mill. Good brakes, suspension and FFR handling should make a smile wrap around your head. I own one of each FFR model and from the work I've seen to daye on the 818 I am more anxious to throw this thing around than any other. I can't wait to drive this thing and the variables we are discussing will be better discussed with data.

Jim wants to let the car speak for itself and that is fine. We're close to the new website and perhaps a more detailed (but not EXACT) parts list of Subie parts that will be needed.

Excellent! I'll be keeping an eye on the website...may have finally found something I would consider replacing my MR2 with, so long as it has AC and a roof (AZ summers are a little extreme to go without that).

[Dave Smith]

I can say that the final body shape #1 that is going to production as I write this is going to make people happy and was tremendously affected by customer feedback, among other things. Right now the schedule dates are the most important, so that folks don't get frustrated with the pace. Keep in mind, we have been on target with this project (that was announced one year ago). We will not take deposits or make wild claims before we've developed the car and the launch plan should be clear enough soon to allow guys to plan their builds accordingly.

[skullandbones]

Dave,

Is there a definite date for the website update or is that just when you and MD get it done? Thanks, WEK.

[2KWIK4U]

Couple of answers here (and btw, Mad Dog and I have HIBERNATED ALL WEEK) working on the new FFR website which inlcudes an updated 818 section.

The final body shape of the first 818 model has been selected and has been fully digitized. It will be a roadster to start with a later soft top for sure and a likely removable hardtop. We will not show the body until we have a driving car. We MAY show the finished CAD model body shape soon if all is good. The project has gone a bit dark and that is a function of us having the data we need and simply wanting to design and build the car as fast as possible without compromising quality or making claims that end up inflated.

Regarding performance though, I do feel that this car will (has to) be on the upper end of what we've done up to now. I can see a 300-350 hp car that weighs 1800 lbs and runs sticky DOT legal tires running easily in the threes (to 60) and 1/4 mile times in the 11's. At the same time I think most people will be BLOWn away with the fun factor (and speed) of a $500 Imprezza donor build even with the torquey little 165 hp mill. Good brakes, suspension and FFR handling should make a smile wrap around your head. I own one of each FFR model and from the work I've seen to date on the 818 I am more anxious to throw this thing around than any other. I can't wait to drive this thing and the variables we are discussing will be better discussed with data.

Jim wants to let the car speak for itself and that is fine. We're close to the new website and perhaps a more detailed (but not EXACT) parts list of Subie parts that will be needed.

The traction issue is a big one, but the crew has a good history with solving those challenges and the car is mid-engined. All I can say is that a spec racer at 2400 lbs and 225 hp/300 lb ft nails 0-60 in 4.5 seconds all day long with toyo prox 888 DOT race tires. I think that accel times will be all over the map. The one thing I am absolutely 100% sure of at this point is that the car will be one of the most entertaining and fun cars to drive on the planet.

This is great news, I can't wait to see what you chose for the first design. Thanks for the update

[spaceywilly]

Thanks for the updates Dave. I am excited about this car again and can't wait for moochfest :D

[Xusia]

Oh how exciting!!! I can't wait to see the final body shape! :D

[Silvertop]

This is great news, I can't wait to see what you chose for the first design. Thanks for the update

Echo that 10X!!!

Here's hoping the Car #1 body reveal happens VERY soon! I'm making my first-ever visit to FFR Friday, March 9. It would be fantastic to get a peek................!

[fateo66]

We're close to the new website and perhaps a more detailed (but not EXACT) parts list of Subie parts that will be needed.

The traction issue is a big one, but the crew has a good history with solving those challenges and the car is mid-engined. All I can say is that a spec racer at 2400 lbs and 225 hp/300 lb ft nails 0-60 in 4.5 seconds all day long with toyo prox 888 DOT race tires. I think that accel times will be all over the map. The one thing I am absolutely 100% sure of at this point is that the car will be one of the most entertaining and fun cars to drive on the planet.

I for one am really excited to get an updated parts list and more definitive mechanical details, that's where the devils at!

[VTX]

I can say that the final body shape #1 that is going to production as I write this is going to make people happy and was tremendously affected by customer feedback, among other things. Right now the schedule dates are the most important, so that folks don't get frustrated with the pace. Keep in mind, we have been on target with this project (that was announced one year ago). We will not take deposits or make wild claims before we've developed the car and the launch plan should be clear enough soon to allow guys to plan their builds accordingly.

Well, that's exciting to hear. Are there any more details that you can share? For example, is it one of the winning designs, or is it a modification of a winning design, or a whole new design?

[bromikl]

The final body shape of the first 818 model has been selected and has been fully digitized.
Emphasis added.

Keep in mind the first body produced won't be the only body produced. I predict a good 40-60% of us will be disappointed with the design. Not because it will be unattractive - but because we each have a predetermined favorite.

[Flamshackle]

I can say that the final body shape #1 that is going to production as I write this is going to make people happy and was tremendously affected by customer feedback, among other things. Right now the schedule dates are the most important, so that folks don't get frustrated with the pace. Keep in mind, we have been on target with this project (that was announced one year ago). We will not take deposits or make wild claims before we've developed the car and the launch plan should be clear enough soon to allow guys to plan their builds accordingly.


Great news Dave,

Simply putting together what we know...

-Rodney O and FFR have already been in contact with each other in regards to the design
-His design was definitely the most "tremendously affected by customer feedback"

It doesn't take a rocket scientist to work out that we are going to be getting something along the lines of this car right here...

7981

AND OH MAN DO I NEED ONE ;)

[DrieStone]

Great news Dave,
It doesn't take a rocket scientist to work out that we are going to be getting something along the lines of this car right here...

I too am interested in seeing what the 1.0 car looks like, however, I believe Rodney hasn't really had a lot of interaction with FFR, so my guess is that the first car is something unrelated to Rodney's design (thinking that if Rodney's design became an alternate in the future FFR wouldn't want the 1.0 car looking too much like it).

[skullandbones]

Well, I don't think the body type will make much difference as far as performance is concerned but I am curious as to how the FFR team will solve the traction problem with this project. I hope they employee some fender flaring or some method of allowing larger tires. Getting 300+ hp to connect to the pavement will be a real challenge. They may go with some fancy adjustable shock combo but that would also drive the price of the suspension through the roof. I think Dave is right: the acceleration numbers will be everywhere until the right combo is learned and becomes common knowledge. WEK.

[kach22i]

I too am interested in seeing what the 1.0 car looks like, however, I believe Rodney hasn't really had a lot of interaction with FFR, so my guess is that the first car is something unrelated to Rodney's design (thinking that if Rodney's design became an alternate in the future FFR wouldn't want the 1.0 car looking too much like it).
Either way, we really don't know what Santa (Dave Smith) is putting in the FFR 818 Christmas box and wrapping up.

[Silvertop]

Either way, we really don't know what Santa (Dave Smith) is putting in the FFR 818 Christmas box and wrapping up.

No, we absolutely don't know. It seems inevitable that we will be unable to resist speculating however, based on the last half-dozen or so posts. I guess I can't resist either.:p

My thinking is that launch #1 will be based on a modification of one of the existing winning designs, either Rodney's or Xabier's. I actually think that Xabier's (with scaled down front openings) may be the one, though I'm not 100% sure why I believe that. Wishful thinking, maybe, or possibly the fact that Dave Smith showed some partiality toward this design in the past. Either design could be an excellent choice, however. We'll just have to wait and see.

[Oppenheimer]

People speculate endlessly about the winner of the big game in the days and weeks leading up to it. Why should this be any different?

So, who is going to start the pool?

[Niburu]

I'm gonna laugh if it turns out to be Stratos replica afterall

[DrieStone]

I'm gonna laugh if it turns out to be Stratos replica afterall

If that happens I'd buy two.

[PhyrraM]

60% In house car reworked or revised - again.
15% Xabier's
15% Rodney's
10% something else

[keys2heaven]

60% In house car reworked or revised - again.
15% Xabier's
15% Rodney's
10% something else

I don't buy this. Dave indicated that Jim's concept was out.

Since RISD was working on the Xabier concept, I'm leaning towards that being the first body.

Dave loved the design and it truly is setup as a roadster. Plus, it can be trackified easily.

[Draco-REX]

45% RodneyO Roadster
40% Jim/VMan hybrid
10% Nosejob Xabier
5% something else.

EDIT: I should state that this is based on Dave's emphasis on the community input on Body#1 (818A?). Rodney's has had tons of input and is already in CAD-ready form. Also, on his last update he revealed a roadster body out of the blue. VMan's also had a lot of input and it's been commented that VMan's nose and tail would go well on Jim's car. And a visitor to FFR stated that the full-scale body was having it's nose reshaped. Dave has also said that he has had HoF moments with both designs.

Xabier's was a favorite early on as well, and Dave LOVED the track concept. With work being done on it already, it's a possibility. But Xabier's hasn't had the input that the other two designs did. And the final 5% is because anything can happen, always leave your options open.

[keys2heaven]

Xabier's had quite the cult following before the design contest was over.

[RM1SepEx]

I like the Xabier concept and think that a top would be easier on one. He sent it to RISD but it didn't get the tremendous feedback on the site. (though about the same number of people actually provided inputs as those who did for Rodney's, his was almost designed by a continued evolution.) Dave told us that he was "talking with Rodney" in past discussions. His is also already in compatable CAD format so...

I'm at 40% Rodneys with signifigant changes that make it fit the molding process etc... but the shape will be obvious

50% Xabier's with RISD input, that means it will also have signifigant changes from what was drawn and shown as the 1/4 scale model. this is by far the most unique body style...

10% I have my head up my *** one of the other's somehow squeeked in Shawn's, Vman's.... I like them both too!

Dave has answered cryptically enough to tease us both ways, he is damn good at that! (I tried to get more info out of him at Moochfest... he had the story down pat, echoed the post above... ) And finally either one will be in my garage as soon as possible!

1800 lbs 225WHP with some simple "teaks" to a stock WRX drivetrain. We are talking smiles that will break your face! Looks, performance, and knowing it's all yours... PRICELESS

[DrieStone]

I've been thinking about this too. At first I considered that the v1.0 was all new, and not based on anything we've seen yet, but now I'm not sure.

I find it very unlikely that it's Rodney's design. I know Dave popped in at one point and seemed to indicate that he liked the direction, but based on the timing, I just don't think that has any bearing on the first version. Rodney has been fairly active in the forum, and was offering changes etc fairly recently. I would imagine he would have disappeared off the forum to preserve the surprise if he was working closely with FFR (or if FFR had taken over the design). I could see FFR/RISD taking over the design without telling Rodney, but I find it unlikely.

Dave also indicated that he didn't love Jim's original design, so my guess is that it died.

Xabier's design is probably the most likely if Dave decided to use an existing design. The forum has been pretty quiet in regard to input (as far as I remember).

That said, a whole new design has some benefits (but can also be risky).

So I'm torn. I think the chance for something based on Rodney's design or Jim's design pretty close to 0%. So I give almost even odds whether the v1.0 car is based on Xabier's design or something completely new (I'm leaning toward something new still though).

So:

Rodney's Design 0%
Something based on Jim's initial design 0%
Xabier based design 40%
Something completely new 60%

[keys2heaven]

I'm going to say that RISD helped shape Xabier's concept as the first body.

I would also re-direct you to this post from last September:
http://thefactoryfiveforum.com/showthread.php?2659-818-Project-Updates-From-Dave&p=31757&viewfull=1#post31757

[Oppenheimer]

I like the Xabier concept and think that a top would be easier on one. He sent it to RISD but it didn't get the tremendous feedback on the site. (though about the same number of people actually provided inputs as those who did for Rodney's, his was almost designed by a continued evolution.) Dave told us that he was "talking with Rodney" in past discussions. His is also already in compatable CAD format so...

I'm at 40% Rodneys with signifigant changes that make it fit the molding process etc... but the shape will be obvious

50% Xabier's with RISD input, that means it will also have signifigant changes from what was drawn and shown as the 1/4 scale model. this is by far the most unique body style...

10% I have my head up my *** one of the other's somehow squeeked in Shawn's, Vman's.... I like them both too!



I'm with you on this one. Agree with all your thinking, but I'll tweak the numbers to make them mine:

70% Xabier, with RISD tweaks
25% Rodney
5% Something else (also a big fan of Vman and to a slightly lesser degree Shawns. Also loved the ScottyB, and the Greek entrant was nice too)

[D2W]

The final body shape of the first 818 model has been selected and has been fully digitized.

Thinking about this quote leads me to believe version 1.0 did not start out as a cad model and it is completed. So where does that lead us? After SEMA Dave said Jim's design was being significantly reworked, I'm assuming the front end on the full size mock-up. I don't remember when or where so I don't have proof but I thought Dave said the RISD guys were going to continue to work on Xabier's design to fix some of the problems. Like the massive front openings and the targa bar. Dave also mentioned a fifth design that was never revealed.

Rodney has been on the forum with updates too much for me to think he is working with FFR. I think his design could be used in the future but I don't believe it will be V1.0.

Vman and Shawn Whetstone's designs are good, but I don't think FFR would use one of them without contacting them directly because they already have cad files existing.

So my thought is:

Jim's design reworked based on forum feedback - 40% (good luck)
Xabier's design reworked based on forum feedback - 40% (could be good, a lot of people liked this design during the contest)
Rodneys forum reworked design - 10% (I like it but why would his cad models need to be digitized)
The 5th nonreleased design - 5% (risky, who know's what it looks like - Stratos roadster?)
All other designs - 5% (I just don't see FFR starting from scratch, and having something done already.)

[keys2heaven]

From the horse's mouth regarding Jim's (a.k.a 'the silver') design:

http://thefactoryfiveforum.com/showthread.php?3965-818-Sample-Model-4&p=49444&viewfull=1#post49444

And, if this were the case back on 1/26, there would have been no time for FFR to rework and finalize the body in less than a month.

I'll say it again...Jim's (the silver version) has 0% chance of being the body at this juncture.

FFR, in my opinion, didn't come up with another design that none of us know about. Given what has transpired via these threads, I'm almost positive that the initial body has to be a tweaked version of Xabier's concept.

And, until Rodney started doing his tweaks, Xabier's was still the odds-on favorite by a majority here and Dave as well.

[PhyrraM]

Jim has seemingly already put his foot down on "technical reasons" to do certain things with the design (such as the fender/door interfaces). I'm not going to call him wrong as he knows the limitations and tolerances of the production medium.

It also appears that tech team have a preferance to use OEM type of lights ('01-'06 Camry lights on the first in-house model). If they were not trying to integrate an OEM light, why wouldn't the inhouse model go straight to Hellas, like the GTM? It would be hard to integrate any OEM assembly into something like Rodney's without a total front end redesign.

I'm still at 60% something FFR created. Although I am also in the camp that says that Jim's car would have looked better without anything next to it for comparision. I'm actually wondering if that is the main reason for a "proper unveiling" at a later date.....to let some of the currently popular styles go a bit stale. At that point a freshly restyle/updated "Jim car" - with no contemporary competition - will be percieved to look alot better (hopefully).

Also, for me, @1800 pounds & 227 HP - looks hardly matter.

[keys2heaven]

Sorry, still don't buy it. Just don't think FFR had the time for a "do over."

The timeline just doesn't support this in my opinion.

[D2W]

From the horse's mouth regarding Jim's (a.k.a 'the silver') design:

http://thefactoryfiveforum.com/showthread.php?3965-818-Sample-Model-4&p=49444&viewfull=1#post49444

And, if this were the case back on 1/26, there would have been no time for FFR to rework and finalize the body in less than a month.

I'll say it again...Jim's (the silver version) has 0% chance of being the body at this juncture.

FFR, in my opinion, didn't come up with another design that none of us know about. Given what has transpired via these threads, I'm almost positive that the initial body has to be a tweaked version of Xabier's concept.

And, until Rodney started doing his tweaks, Xabier's was still the odds-on favorite by a majority here and Dave as well.

"The silver car design is dead (this version at least)... " This is the exact quote from Dave in the thread you linked, and I know Dave said they were reworking the design (page 6 of the same link on 11/16). So a new version is wholly possible. I also agree that Xabier's design was very popular and could very well be the one. Everything else is a long shot at this point.

PhyrraM, I'm kind of with you in the fact that I think V1.0 is going to be something FFR created. But with all the work they put into modeling Xabier's design I think it could be Xabier's or Jim's. Who know's maybe FFR shot themselves in the proverbial foot by having the design contest. If not for the exposure to all the great designs we might be all singing the praises of Jim's design right now.

[RM1SepEx]

Rodney's would make a damn nice coupe... as iteration "B" and would "diversify" the purchasing options...

Dave's word's really give us Xabier's and Rodney's as the only front runners meeting his description, inputs from the online community yada yada yada... They are two very viable iterations that look nothing alike, giving buyers options, over the longer term

Rodney had many tweaks done when I visited F5 in December and took the infamous Dave shielding/hiding the models photo! That's when he stated that he had chosen to rework Xabier's with RISD and that he was talking/working with Rodney as well and that he would not build the Nuphone, (spelling) GRM contest winning design... Since then he flushed Jim's design too

I'm wondering how the computer's wind tunnel testing looks for Rodney's vs the other two swoopy coupes... they both look smoother and cleaner than his but the numbers would be very interesting.

The high mileage option could be based on the best of these 3... or Make Rodney's the coupe and then provide a 3rd body option for the high mileage body... (Dave's swatch watch comments, remember... that helps shape this entire discussion)

Remember whatever it is will be tweaked to THEIR tastes (it's his money and their ***es on the line) and manufacturing and assembly concerns are critical.

We need to be happy and proud/honored that they allowed us to participate in such an exciting process for a great groudbreaking product

Dan

[Oppenheimer]

Yes, honored to have been allowed to participate, that is how I feel.

As for which model for which purpose, I'm of the mind that each for each. No reason Rodney can't be offered as Roadster, Coupe and Targa. Same with Xabier (well, not so much Roadster in strict sense). Point is they could just make each design, and offer each one in multiple forms, without, seemingly, making things too complicated or costly to manufacture.

Whichever one ends up as the slipperiest Coupe, could be the default basis for the MPG version. Though again, no reason someone couldn't build their MPG commuter off the second slipperiest, and do it as a Targa, if they didn't mind losing a few MPG for their desired look.

Which design for which purpose? Each-for-Each. Swatch-Watch.

[apexanimal]

yeah i think xabier or in-house to be the roadster...

still hoping they run w/ rodney's for the track monster...

[RM1SepEx]

excellent summary Oppenheimer!
I agree, no reason not to task any body shape into any purpose...
Each has it's pros/cons why not compromise MPG a bit if you prefer a less slippery shape for example...

[Silvertop]

excellent summary Oppenheimer!
I agree, no reason not to task any body shape into any purpose...
Each has it's pros/cons why not compromise MPG a bit if you prefer a less slippery shape for example...

Must also agree!!

[Dave Smith]

I honestly think that Jim is sandbagging when it comes to performance numbers. I am not particularly concerned about hook-up because the weight distribution and fender area help there. The shape is never going to make everyone happy, but now that the company is under unified leadership/ownership I feel it is such a capable platform that it would be a major misseed opportunity to not develop 2-3 body shapes and purposed vehicles on this chassis layout. With that in mind it brings the 818 into much better focus as we are at the headwaters of a long product run that can easily (at least quiockly based on short lead times of CAD body shaping to manufacturing) accomodate multi-purposes... My dream of a swatch watch car platform. The website is coming along but the 818 details are still not as tight as I'd like. Working on it.

[BipDBo]

Dave, I know that you have made a big deal over HOF design, but that won't define the car. The car will be defined by and be successful because of its simplicity, price and performnce. With its low weight, rearward weight distribution and power potential of the boxer engine, it's got phyisics on its side, so the performance will be there.

Aesthetically, I wouldn't care if the body were made to look like a rusty Gremlin, but most customers buying the roadster version will care quite a bit about styling, and they should. The track version, IMO has different requirements. It should be defined more by function than form. The body should cut through the air with low resistance, provide downforce, and give proper ventilation to all of the hot bits (with upgrades). It also needs to be lightweight, inexpensive and tough. Styling should follow behind those design parameters.

[Dave Smith]

Agreed on all but I have learned firsthand that the FIRST thing that draws someone to a car is looks and the 818's success depends on looks to a very large degree. The Lancia Stratos is permanently ectched in my brain because the LOOKS inspired my dreams of driving one. I have never dreamed of driving a rusty gremlin (although I did go for a ride on the hood of one in high school, but that's another story). As my old Boss from California loved quoting "you gotta have the steak and you gotta have the sizzle".

[Oppenheimer]

Agreed on all but I have learned firsthand that the FIRST thing that draws someone ....is looks and ...success depends on looks to a very large degree.

Yes. You could just as easily be talking about finding your Significant Other. Looks get your attention, then its the rest that makes you realize, this is the one.

[Movieman]

Yes. You could just as easily be talking about finding your Significant Other. Looks get your attention, then its the rest that makes you realize, this is the one.
Well said or as I say it: The flashy brass on the street may grab your eye but it's the platnium at home that you stay with..
Said by a guy twice divorced but the saying still holds true.:D

As to the talk about looking like A Stratos I doubt it as there are kits that exist for that.
Stratos is one of the sexiest cars I ever saw but unless your under 5'8" and 160 don't try to get in one.
Tiny inside..

[RM1SepEx]

:o So my question for Dave is are you having a good time watching us disect your words and attempt to guess what we will see? It seems like we can't help ourselves! :o

[16g-95gsx]

Yes. You could just as easily be talking about finding your Significant Other. Looks get your attention, then its the rest that makes you realize, this is the one.

Subconsciously I think this is why guys are so into cars, it creates the same emotions in us. You need visual attraction to draw you in, and then the performance that you expected to keep you there :). If you sit and think about how we approach both women and cars you'll find endless amounts of similarities between our choice in cars and our choice in women.

[16g-95gsx]

If you had that much power in the 2 liter, it would be coming at very high revs. Since you wont have the jolt off the line, asuming you want the clutch to last, it may be able to keep a better traction than a 2.5 with that much torque. That sure would be a laggy setup. Lag can be fun if you know how to drive with it.

Not necessarily calling you out, but comments like this always make me chuckle to myself. The torque production of a 2.0L can be extreme depending on turbo selection. Since most guys would run stockish turbos I bet you'll find most complaining about the abundance of torque causing issues rather than the lack of it. I know what you're getting at, but there is a large difference when stroke and turbo's are considered into the equation, as not all 2.0L's are the same and most stockish setups are tailored to low end grunt rather than top end power. Combine this with the fact that the 818 would have a better flowing exhaust and intake right off the bat, and you already have yourself significant torque in an otherwise "stock" 818. Well over 200ftlbs at the tires in what will likely be a total 2000lb with driver car. That's torque to weight equivalents comparable to most modern domestic performance cars nowadays.

[wantscobra]

I "expect" that it will "perform" vastly better than basically any other car that you can get on the road - new - for 15k.

After all, that generally is what F5 does.

That is all.

[bbjones121]

Sorry, my comment was not understood correctly. Of course it is dependent on turbo. It is the physics of the things. Unless you are able to defy physics, the more power you push on a smaller displacement, the faster up the power curve that will come. The larger the displacement, the same power can be achieved lower on the power curve. It is very simple, more power = larger turbo (ie, one able to move more air), larger turbo = more mass to spin, more mass to spin = greater volume of exhaust needed, larger displacement = greater volume of exhaust gases. Just rearange these equations as necessary to understand my comment.




Not necessarily calling you out, but comments like this always make me chuckle to myself. The torque production of a 2.0L can be extreme depending on turbo selection. Since most guys would run stockish turbos I bet you'll find most complaining about the abundance of torque causing issues rather than the lack of it. I know what you're getting at, but there is a large difference when stroke and turbo's are considered into the equation, as not all 2.0L's are the same and most stockish setups are tailored to low end grunt rather than top end power. Combine this with the fact that the 818 would have a better flowing exhaust and intake right off the bat, and you already have yourself significant torque in an otherwise "stock" 818. Well over 200ftlbs at the tires in what will likely be a total 2000lb with driver car. That's torque to weight equivalents comparable to most modern domestic performance cars nowadays.

[skullandbones]

Good reading on the torque, boost, displacement, etc. factors discussion is "Maximum Boost". It's the bible of turbines and gives excellent formulae to help decide what combination will work for your application. I'm not an engineer but do get into the physics of this phenomenal technology.

I have my son scouting out a WRX deal on the internet. He searches, buys, and flips cars. So he should be able to find one. He had never heard of what I am looking for but now he's getting up to speed. I want to own and drive one to see how it really feels compared to what I have experienced. The only road block I see so far is that those for sale are usually pretty pricy.

I have been listening to the discussions and want some real life comparison to go with what I have heard about the WRX's like, in one thread they said, "the spec cars won't stay up with the WRXs". I got to drive a Farrari 360 Modena (2003) this weekend for about 45 minutes. That's the first exotic I have ever driven and it was pretty impressive. It's also the first mid engine car I have ever been in. If the 818 performs like the 360, I would be more than happy (accleration and speed). I would expect it to perform better in a track environment (lighter and more road feel). WEK.

[RM1SepEx]

Ferrari 360

400hp, 275 torque, 3064 lbs
7.7 lbs/hp 11.1 lbs/ft lb

if you use 2006+ WRX with 2.5L

230 HP, 235 Torque, 1800 lbs

7.8 lbs/hp, 7.7 lbs/ft lb

Couldn't ask for a better comparison/benchmark!

It's a given F5 does a great job with chassis handling etc, The car will be well balanced and stiff with coil overs and Konis

The 818 will have a better torque curve (area under HP curve is directly related to acceleration capability) and it has both a lower torque curve and more torque per lbs.

The 818, properly setup should outperform a 360....

and I couldn't agree more :-) that would be break that permanent smile off my face performance!

and I'll assume better downtube, exhaust and intake to get more than the stock 230 HP, I expect 250-260 at the engine

[bobzdar]

I don't know. With the gtm, the factory suspension geometry needed work for heavy track use, including kit modofication. The 360, well, doesn't. If you get the 818 set up properly (and that may mean modification from stock) it should hang with the 360 and beat it on tighter tracks, but will lose out on higher speed tracks due to its lack of power (power/weight starts to fall apart when aero drag takes over and pure hp wins). The whole torque argument is garbage as if it mattered, an f1 engine would get spanked by a tractor engine. Area under the hp curve is a different story, and if you look at the hp curve of a 360, it's pretty meaty up top where the engine stays in track use (6000-8700rpm).

[Thorne]

I'm a Subaru Pro tuner and My personal subarus have ran 12.3 @ 335awhp full weight WRX and later made 370awhp on a EJ22E(NA MOTOR+18g) . My current setup is a EJ257 swapped into a RWD Impreza L wagon. It's scary to drive I don't have enough tire.

I'm debating on building this or having the shop I tune at part time build me basicly a super gokart. Target weights are about the same . I've crunched the numbers and if we can hook 400rwhp will run 9's in the 1/4. I've got doubts about front diff holding that much power though. I've broke 1 R160 so far in rwd mode running 16psi. I also broke one fwd diff. I'm aiming for super car level performance though. on low boost my full weight 97 wagon with a ej257+18g beat a 2011 gt5.0 with a stage 1 tune. BADLY. But I've not dynoed the car on rwd or on the 2.5l.

[Oppenheimer]

I don't know. With the gtm, the factory suspension geometry needed work for heavy track use, including kit modofication. The 360, well, doesn't. If you get the 818 set up properly (and that may mean modification from stock) it should hang with the 360 and beat it on tighter tracks, but will lose out on higher speed tracks due to its lack of power (power/weight starts to fall apart when aero drag takes over and pure hp wins). The whole torque argument is garbage as if it mattered, an f1 engine would get spanked by a tractor engine. Area under the hp curve is a different story, and if you look at the hp curve of a 360, it's pretty meaty up top where the engine stays in track use (6000-8700rpm).

FFR is planning a track version, more suspension, brakes, etc. No reason you couldn't fit those to your street 818 (I'm sure that will be a popular option). But I think RM1SepEx was talking about road going performance, not so much track. There, torque does matter. We're not talking just about street racing, but seat of pants enjoyment of the car.

But if you want to talk track, and HP and top speed, for the a fraction of the cost of the F-car, you could do a few mods to your 2.5 STi motor and be well north of the F-car's power. No reason you couldn't break those numbers even with a Plane-Jane WRX powerplant.

Who of us if we had unlimited budgets would not have a fleet of supercars in our stable. Might we still build an 818? Perhaps, but likely for some different reasons. Is the F-car a super fun car? Would we all mind having one? With the 818 we don't have to dream, its within reach. That it can even be discussed in the same breath as these exotics is mind-blowing. That it will be able to eclipse these mega-cars in many performance categories is beyond mind-blowing.

[RM1SepEx]

Correct, we are talking performance as a whole, not heads up at Laguna Seca etc... It should be able to out accelerate, turn as well and brake better. F5 will work the suspension to make it very capable and competitive and updates must be expected over time.. speaking to the GTM issues. As far as overall top speed, yup just HP vs Aero drag but who really can use it unless you track it at a really large track or have access to the salt flats or a land speed record location?

A high strung engine works fine on a track but isn't as near satisfying on the street...

I see street use, some autocross and perhaps a track day here and there, I'm not building a race car

[skullandbones]

I do believe the vehicle is limited by it's environment. Not many of us will be driving a FFR project at it's optimal potential unless you are driving a spec racer or a coupe in one of the 25 hr endurance races. I better not forget the drag racers. I suppose you can specialize and make one a "straight line rocket". But if you are driving on the street, you will experience snapshots of performance. I think the 818 can be set up to meet that need without too much effort. It will help me cross one more thing off my auto bucket list: owning a turbo powered hot rod!!! WEK.

Note: I just brought the 360 thing up to use as a benchmark. Now that I have done it, I can say I drove it but as a dream car, probably not in my case.

[RM1SepEx]

You have some very serious toys! Even a 300 HP STI powered 818 would be your lowest powered toy!

[bobzdar]

Correct, we are talking performance as a whole, not heads up at Laguna Seca etc... It should be able to out accelerate, turn as well and brake better. F5 will work the suspension to make it very capable and competitive and updates must be expected over time.. speaking to the GTM issues. As far as overall top speed, yup just HP vs Aero drag but who really can use it unless you track it at a really large track or have access to the salt flats or a land speed record location?

A high strung engine works fine on a track but isn't as near satisfying on the street...

I see street use, some autocross and perhaps a track day here and there, I'm not building a race car

Have you ever driven a 'high strung' Ferrari on the street? I can assure you that it's plenty satisfying, more so than the muscle cars I've owned. It's not like 265ftlbs of torque is anemic, that's more than your typical 4 door sedan in a lighter package. If you want to go really fast, there's this clutch thing you press in and a metal stick you move that puts you right onto the sweet spot of the power band where torque is irrelevant.

I want to build my own car, which is why I'm interested in the 818, but realistically the $15k build will not put you even close to anything post 348 on the Ferrari scale. A $20k wrx based kit build will probably get you close to a 355 without the refinement or basic creature comforts of one. At 25k to 30k I think you can realistically expect to compete on performance and maybe build quality with a 355 or 360. Or you can do like I did and spend a few grand more and just get the Ferrari. Where the 818 destroys the Ferrari is on maintenance costs.

[Oppenheimer]

Yes, you do get something for all that extra Ferrari $$$. No one is saying those cars don't offer something that is worth the price of entry (which is more than just build quality and creature comfort, the sound, the feel, the visceral experience - the 818 won't match all that).

But the discussion was about 'keeping up with' the Ferrari (on the street). RM1SepEx pointed out how the two cars have similar power/weight ratios, with the 818 having a significantly better torque/weight ratio. Though most 818's will probalby not be built with stock engines, even a few cost effective mods will bring those numbers up quite a bit.

You pointed out how the F-car has more HP, so it will have better top speed (aero vs hp being the deciding factors). That is ture, top speed to the Ferrari for all but the most potent 818 builds.

But I think its hard to argue against your (probable) typical 818 build (WRX based, a few minor hp mods) having little trouble hanging with the F-car in question in most street (and even most track day) environments.

With the 818 you get Ferrari like performance, at an economy car like price

With the Ferrari you get Ferrari performance, Ferrari panache, Ferrari cachet, Ferrari visceral experience, Ferrari envy, Ferrari supermodel wants to go for a ride, at the Ferrari price

But you DO GET the Ferrari performance with the 818.

[shinn497]

Paint it red, put in a leather interior, Ferrari badges and people will THINK it is a ferrari.

Point is if you want panache and good looks it will be possible. Most people aren't supercar enthusiasts.

[bobzdar]

Yes, you do get something for all that extra Ferrari $$$. No one is saying those cars don't offer something that is worth the price of entry (which is more than just build quality and creature comfort, the sound, the feel, the visceral experience - the 818 won't match all that).

But the discussion was about 'keeping up with' the Ferrari (on the street). RM1SepEx pointed out how the two cars have similar power/weight ratios, with the 818 having a significantly better torque/weight ratio. Though most 818's will probalby not be built with stock engines, even a few cost effective mods will bring those numbers up quite a bit.

You pointed out how the F-car has more HP, so it will have better top speed (aero vs hp being the deciding factors). That is ture, top speed to the Ferrari for all but the most potent 818 builds.

But I think its hard to argue against your (probable) typical 818 build (WRX based, a few minor hp mods) having little trouble hanging with the F-car in question in most street (and even most track day) environments.

With the 818 you get Ferrari like performance, at an economy car like price

With the Ferrari you get Ferrari performance, Ferrari panache, Ferrari cachet, Ferrari visceral experience, Ferrari envy, Ferrari supermodel wants to go for a ride, at the Ferrari price

But you DO GET the Ferrari performance with the 818.

Lets forget the street portion, because the fact of the matter is that you cannot safely explore the limits of these cars on the street. I messed around a bit when I first got my 355 on the backroads near my house and looked at the speedo and was at 3x the posted limit. I was not pushing it hard (no tire slippage or anything). After I tried to find the limits of a 911 on the street once and it ended badly, I won't go there and quickly parked the 355 in the garage until I cooled off. Suffice to say either car will be plenty fast to get you in trouble with the law or killed pretty quickly on the street, so there's no point comparing them there. I would venture that the Ferrari would be a lot more comfortable anyway, with it's climate control, power windows etc.

Track wise, I will go out on a limb and say a box stock 818 will not handle as well as a box stock 348 and up Ferrari. The GTM had suspension geometry issues (not sure if the kit is updated now?) that were worked through by some people racing them, the type 65 coupes with IRS did as well and I have a feeling we will see the same with the 818, at least initially. A stock wrx build will probably be in the 20k range and I think this is the minimum you will want to start with if you are trying to keep up with or beat a 90's up Ferrari - or say a C5 vette. Add in around 2 grand for rims and sticky tires - Most Ferraris will be on Michelin Pilot super sports on the street and better on the track. Add another 2 grand for adjustable Bilsteins (355 up have them stock). You're at 24k without any engine mods. Figure a grand to get the power up to around 250hp and you're at 25k. At this point, you will need a full track day or two to get the suspension set up before I think you can be fully ready to take on the 355 or C5 barring having to do any major modifications (cut and weld mounting points, etc.). That's not exactly cheap...considering you can get a 2005 C5 vette with the z51 track package for the same price.

I want to be clear in that I love the idea of the 818 and am considering one, but people need to be realistic in what the performance actually will be and at what cost. I've been down the road before and matching what you thought the car would be on paper to what it actually is always takes more than you expect, so my 25k may be low...

[skullandbones]

I'm not sure where the WRX/STI setups like to operate (rpm wise). I had to stay under 6500 rpms in my F car ride (total $250 great deal) or pay a premium of $2500 to rev to 8000+. Needless to say, I did stay in the sub 6500 rpm range (and no rev limiters but good LED progressives). The assistant kept saying that the peak hp was in the 5500 to 6500 rpm range. I didn't believe that. He went higher while driving to the staging area. While going around a "roundabout" he punched it to at least 8000 rpm and the roar of the engine and the "visceral feeling" was very evident. So just approaching that sort of performance in a sub 20K car has to be mind blowing. I can't see myself in a GTM project for the same arguments as for owning an exotic but I can see myself in an 818 project without even a second thought! WEK.

[bobzdar]

He was way off, peak HP is at 8500rpm for the 360. The engine doesn't really come fully on song until around 6k...I think the wrx redlines around 6k and the sti around 7000? Rev limit on the 360 is 8750rpm. They will be very different driving experiences in terms of power delivery.

[skullandbones]

So what would get the WRX/STI into that territory? I know you can take a stock 5.0 that operates comfortably in the 5000 to 6200 (peak hp) range without floating the valves and add a performance pkg (heads, springs, roller lifters, cam, etc) for about 3k and get usable power in the +6500 range. What would it take to do the same for the WRX/STI? I think 6500 to 7500 would be pretty impressive myself. The exhaust note and visceral feelings would be added features, too. Thanks, WEK.

[StatGSR]

^ the jdm sti engine already revs to 8000 stock....

[spaceywilly]

He was way off, peak HP is at 8500rpm for the 360. The engine doesn't really come fully on song until around 6k...I think the wrx redlines around 6k and the sti around 7000? Rev limit on the 360 is 8750rpm. They will be very different driving experiences in terms of power delivery.

You are correct for the current WRX and STI, but there are WRX engines that rev to 8500RPMs. The EJ207 (JDM STI engine) revs to 8500 and the V7/V8 edition can be imported relatively cheaply. They also have a twin scroll turbo, AVCS, and semi-closed deck block. I think it would be an awesome engine in the 818. The 2.0L WRX engine (02-05) and 2.5L STI USDM engine revs to 7000. The 2.5L WRX (06+) engine revs to 6500.

[Evan78]

I think the wrx redlines around 6k and the sti around 7000?
7000rpm redline - US WRX 2002-2005 (2.0L EJ205 engine)
6500rpm redline - US WRX 2006+ (2.5L) (EJ255 engine I believe)
8000rpm redline - JDM STi (2.0L EJ207) not sure about years

I think US STi has a 7000rpm redline.

rev limited is a few hundred over redline

[skullandbones]

So is that maxed (large valves, cam, etc) out or does the aftermarket supply performance packages like I referred to for the 5.0? I will try to get up to speed to self educate but in the meantime help me out here. It may be that I am comparing apples to oranges since there is a turbo involved but it would be nice to know how much one has to invest to get say 50 hp increase. I don't hear as much discussion on real specific combinations as I do on the other forums. One question I have is is the tuning aspect more important than the bolt ons and machining to get the power? If that is the case, can you drive a highly tuned one on the street or do you have to switch tunes for the specific use? I hope that isn't the case. It would be like having a cam that lopes so hard you can't idle at a traffic light. Thanks, WEK.

[RM1SepEx]

Wow talk about getting a new tangent going... I'm with Oppenheimer

I was just trying to say that with acceleration being directly linked to the area under the HP curve, and mass, assuming a great stiff chassis, Koni coil overs, good geometry, etc... the raw numbers look damn good, not trying to say that it would be "better" than a Ferrari, just perform as well, in general terms

2005 Ferrari 360 = race car for the street $150,000 ?
818 = race car for the street $15,000 ?

And it will be done under budget of $15,000 with a 60,000 mile or less 2006+ WRX drive train

Mechanical Eng., Married 28 years, beautiful wife, 88 Pistons :p:), don't need to be chased by models :rolleyes:

[spaceywilly]

So is that maxed (large valves, cam, etc) out or does the aftermarket supply performance packages like I referred to for the 5.0? I will try to get up to speed to self educate but in the meantime help me out here. It may be that I am comparing apples to oranges since there is a turbo involved but it would be nice to know how much one has to invest to get say 50 hp increase. I don't hear as much discussion on real specific combinations as I do on the other forums. One question I have is is the tuning aspect more important than the bolt ons and machining to get the power? If that is the case, can you drive a highly tuned one on the street or do you have to switch tunes for the specific use? I hope that isn't the case. It would be like having a cam that lopes so hard you can't idle at a traffic light. Thanks, WEK.

My advice is to poke around on NASIOC, there's a lot of noise on there but also lots of useful threads about these exact kinds of questions. I know someone was running 600hp and 28psi with a 9000RPM redline on an EJ207 but I'm not sure what kind of mods it took to get there, or if it was driveable on the street (I'm guessing not). However even in stock form it will have better lb/hp than the 360 if the 818 meets it's 1800lb target weight, and with AVCS and the twin scroll turbo it will definitely be streetable. Subaru engines in general are easy to tune and get a lot of hp out of without spending much at all, and you can generally find lots of guidance out there for whatever you want to do (just be careful who you listen to).

[bbjones121]

So is that maxed (large valves, cam, etc) out or does the aftermarket supply performance packages like I referred to for the 5.0? I will try to get up to speed to self educate but in the meantime help me out here. It may be that I am comparing apples to oranges since there is a turbo involved but it would be nice to know how much one has to invest to get say 50 hp increase. I don't hear as much discussion on real specific combinations as I do on the other forums. One question I have is is the tuning aspect more important than the bolt ons and machining to get the power? If that is the case, can you drive a highly tuned one on the street or do you have to switch tunes for the specific use? I hope that isn't the case. It would be like having a cam that lopes so hard you can't idle at a traffic light. Thanks, WEK.

I have a 2.5l turbo. This is best cost/hp upgrade order in my opinion. Obviously some of these will be my best estimate. Understand I am at a mile high elevation and giving numbers from the most conservative dynomameter, so numbers will sound low (20% I would guess).
Stock (baseline cost) - 230hp(rated), 170(awhp)
Cobb AP ($500 used) etune only - 190(awhp) this expensive, but needed for future mods
High flow DP ($200-300 used) etune only - 214(awhp)
High flow UP ($60-$80) etune only. - 220(awhp)
Cold air intake ($100) etune only. - 230(awhp)
Cat back exhaust ($400) - 240(awhp)
Larger intercooler ($400) - 245(awhp)

Now i am going to jump a few because i cant guess what each would do separately.

18g turbo($600-800 used,), larger injectors ($300), professional tune ($300) - 305(awhp)
Extra tune for e85 fuel ($50) - 325(awhp)

Then warm your engine up properly and go easy on your clutch and it should last for a long time.

Almost double the power for $3k to $4k easily.
Prices on my legacy are higher than you would expect for a wrx.

[Evan78]

My numbers are stock OEM. Not a lot of people get into upgraded valvetrain and I never have either. I don't think the bang for the buck is very good in most situations. Usually people are running turbos that are running out of steam toward redline, especially all the stock turbos, so there's usually not a good case for raising the rev limit.

You mind find a couple forums on nasioc helpful for examples - Proven Power Bragging (http://forums.nasioc.com/forums/forumdisplay.php?f=79) and Built Motor Discussion (http://forums.nasioc.com/forums/forumdisplay.php?f=144).

Cost of 50hp increase depends on existing setup. On a stock Subaru, getting rid of the factory turbo back exhaust and a tune results in 40-70whp increase for $1500 or less. After that, the next steps are usually a bigger turbo, injectors, fuel pump, perhaps intercooler (and tune of course). Power increase determined by turbo size.

BBJones121 has accurate approximate costs.

Spaceywilly raises a good point - the JDM EJ207 motor is a different beast and does a much better job at making power at the top end.

[bobzdar]

Your 15k or under build will not have konis, good tires or anything else unless you get the wrx for free.

It's fairly simple math.

818 kit is 9k
Wheel and tire package is 2k
Bilstein wrx setup is 2k

You're at 13k without even having a donor yet. A 2002-2006 wrx runs around 8k these days with under 100k miles - that's 21k. Add 50hp worth of tuning and exhaust and you're at $23,500 (using above quotes). That's with around 250hp and a good suspension and good tires. And nothing else.

I think you'll see 15k builds, but they'll be bare bones imprezza builds which won't have supercar performance (though quick for sure). I think it sounds great to say you're going to be as fast as a 150k ferrari for 15k, but there's no way in hell. Besides, 150k buys you a 430 these days, a 360 is less than half that.

[305mouse]

I'm sorry Evan but a turboback and a tune won't get you 70whp and should cost under $1500. You might get 40 whp if you're lucky. What you will get is a much smoother curve. I picked up a catted DP and cat back for $600 and a custom tune will probably cost between $300-450.

Bob, koni's come with the kit

[shinn497]

Yeah I'm in the camp that parts alone we can get a 15k build with konis and wrx running gear. This is what dave has promised all along.

there are hidden costs, paint, tools, things you just want to put on. I expect the average cost to run somewhere around 20k for these.

I think 400WHP is the magic number for supercar performance that is enzo area. I think at that kind of WHP you would be pushing low/sub threes.

The thing is that is doable. It would might end up with a kit price of 35-40 k but that is a WHOLE lot more feasible than 150~200k. This is why I find the 818 so exciting. It has humble beginnings but the possibilities are endless.

I did some reasearch and I really want an EJ207. People that have it love it. It is apparently a smooth high revving engine with a fast spooling turbo depending on the model year.

Btw the breakdown is as such:

V7 - forged internals
V8 - twin scroll
V8 spec C - twin scroll plus forged internals

Those are the most highly recommended. There are some aftermarket turbos by litchfield, tomei, and some others. With these the upper limit is I beleive 500BHP on pump. A lot of people have the former on NASIOC.

My plan is to build the basic build pretty it up and either engine swap the tuned ej207 in later and run E85. Can you say rare and exotic? Yes please.

[Evan78]

I'm sorry Evan but a turboback and a tune won't get you 70whp and should cost under $1500. You might get 40 whp if you're lucky. What you will get is a much smoother curve. I picked up a catted DP and cat back for $600 and a custom tune will probably cost between $300-450.

Bob, koni's come with the kitI said $1500 or less. Depends on brand, used/new, etc. Tuner costs vary quite a bit, dyno time is not cheap if you go that route, etc. Many elect for AccessPort for engine management instead of open source, that's another cost that goes into the tune.

I don't know what you're basing 40whp on, but every turbo Subaru setup (2L, 2.5L, TD04, VF39, VF52, etc, etc) should get 40whp MINIMUM from a turboback and tune.

In my experience, the 2.0L WRX will put down around 170whp in stock form. Turboback and tune usually ends up around 210-225whp.

STi's seem to dyno around 225whp from the factory and approach 300whp with turboback and tune.

Torque gains are usually bigger than the HP on the 2.5L engines, especially with the VF turbos (as opposed to the TD04). My dyno tuned 2005 Legacy has a turboback and larger top mount intercooler with stock turbo and put down 260whp/320wtq on a Mustang dyno. I don't have a baseline since it was already modified when I bought it.

[bbjones121]

...every turbo Subaru setup (2L, 2.5L, TD04, VF39, VF52, etc, etc) should get 40whp MINIMUM from a turboback and tune.
Definitely agree with you here Evan. The downpipe, mufflers, and tune are big hold ups. The stock tune alone is very conservative.

[bbjones121]

What you will get is a much smoother curve.

I am sorry, but the smoothest curve you will ever get is from the factory tune. Do you really think Subaru only spent $300-450 and paid a local shop to put the factory tune job on their cars? Absolutely not, they probably had several engineers, experts in everything to do with Subarus spend days and maybe weeks perfecting it.

[Xusia]

You are forgetting that the OEMs have to consider emissions and other such things. Yes, they have experts... who's hands are tied. An after market tuner doesn't have those same restrictions and often achieves better results for that reason.

[autostang]

I am sorry, but the smoothest curve you will ever get is from the factory tune. Do you really think Subaru only spent $300-450 and paid a local shop to put the factory tune job on their cars? Absolutely not, they probably had several engineers, experts in everything to do with Subarus spend days and maybe weeks perfecting it.

I have to disagree with this. I have an 09 wrx and when it was stock 3rd gear would feel like the engine was being hit by small surges all the way through the power band when the pedal was to the floor. Add a tune and this completely smoothed out and felt like one wave of power. Even my mom commented on the difference and she is by no means a car person. Before getting this car I would have completely agreed with you and it shocked me a bit.

I am a bit curious to see if the 818 uses the stock downpipe or a fabricated piece and how that will effect performance.

[bbjones121]

I guess i am more optimistic about Subaru engineers than some. Bad gas, turbo wastegate friction, brake pads, clutch issues, and many other factors could be involved with surges. Your ECU map may have been corrupted. Nobody can tell what the curve actually looks unless you conect a computer and analize the cars parameters.

[bromikl]

What is the theoretical limit on tire-to-road friction? In an 1800 lb car, 200Hp will spin two tires faster than you can sneeze - without dropping the clutch. Sure, your engine could make 450Hp. But one day you'll be in 5th gear at 60 MPH and you gun it. Next thing you know you're fishtailing and rolling your $20,000 toy. In the real world, there's only two places to use more than 250Hp in an 818: The drag strip, and the dyno.

[Niburu]

What is the theoretical limit on tire-to-road friction? In an 1800 lb car, 200Hp will spin two tires faster than you can sneeze - without dropping the clutch. Sure, your engine could make 450Hp. But one day you'll be in 5th gear at 60 MPH and you gun it. Next thing you know you're fishtailing and rolling your $20,000 toy. In the real world, there's only two places to use more than 250Hp in an 818: The drag strip, and the dyno.

THIS is why I'm seriously considering doing a built 2.5 NA version, plus then I don't have to worry about aall the turbo stuff.
As a side note it's not hp that spins the tire, but rather torque - I've owned RX-7's so I know what a lack of it feels like with plenty of HP.

[Dave Smith]

I'm stoked to see this thread continuing on the performance questions. I met with Jim and the Subie guys at AJW yesterday and we were discussing this very thing. I want a stock wrx engine for all vehicle testing, but I also want an over-the-top mil for bragging rights and insane antics. I WANT the car to be too fast. Jim is in agreement on the stock mil, but, as always, super logical and arguing for a reasonable 300-325 hp modded WRX for track and uber-peformance. The naked truth is that most guys build too much power and don't build a balanced sports car. The AJW crew were literally laughing out loud as many of their boys run 400 hp in street WRX's. We ALL agreed that a 165 hp imprezza build will be more fun than anyone really realizes and the ability to build one on target will be quite easy. The difficult part is getting a full tube framed car with modern suspension, paint-free body, and everything else for $9,900. We are confident we can do that, the exciting thing is that if you open the envelope from $15K to $20K, then all hell beaks loose on hp, brakes, suspension, and all-out performance. Still, we have to get the competent base line first, the foundation on which all these cars will be built... No compromise on the body and chassis. tough work going on right now. Also, new website should launch today with updated parts list on the 818 (but no final body images just yet.. still days/weeks away).

[bobzdar]

THIS is why I'm seriously considering doing a built 2.5 NA version, plus then I don't have to worry about aall the turbo stuff.
As a side note it's not hp that spins the tire, but rather torque - I've owned RX-7's so I know what a lack of it feels like with plenty of HP.

It's torque where the tires hit the ground, which is completely dependent on flywheel horsepower, not flywheel torque (due to gear reduction) once the car is actually moving. A 300hp engine will have more torque at the tire at the same rolling speed than a 250hp engine. Do the math and you'll see that is always the case, no exceptions, no matter the rpm it's generated at. Of course, you have to get in the proper gear to get the engine at it's horsepower peak to get maximum torque at the tires at any given speed, but that's what the transmission is for. Magnitude of torque by itself is a completely meaningless number - it's torque coupled with rpm that's useful if you want to do work. The problem with torque by itself is that there's no time component. So yeah, you can apply 400 ft lbs. of torque, but how quickly can you do it? I can apply 1000 ft lbs. of torque if you give me a long enough lever, but I can't do it very quickly. I can also spin something at 7000rpm with enough gearing, but I'd probably struggle to do so with more than an inch lb of force. Once you combine the two and couple rpm with torque, it's horsepower. So the determination of whether you have enough force to overcome the friction your tires make with the road at 60mph is dependent completely on horsepower because there's a time component involved. I don't know if that makes sense as I explained it, but if you break out the math there's no way around it.

I was not aware that the stock kit came with Konis, that's definitely a good thing. Are they the double adjustables?

[Niburu]

have you ever driven a rotary powered car?

[skullandbones]

Dave,

That's great news. I hope the reveal is days and not weeks.

I have to agree with Jim on the hp for the first mod engine (car for the masses). I think there are budget concerns for most people so 300 to 325 hp is doable within the sub 20K where 400+ blows that out of the water. I would bet 80% of the builds will end up in the lower hp range kind of like the roadster. I am thinking the builders fit a normal curve but I could be wrong. It sure would be interesting if FFR could put some of those numbers together some day (in your spare time!). Thanks, WEK.

[spaceywilly]

I'm stoked to see this thread continuing on the performance questions. I met with Jim and the Subie guys at AJW yesterday and we were discussing this very thing. I want a stock wrx engine for all vehicle testing, but I also want an over-the-top mil for bragging rights and insane antics. I WANT the car to be too fast. Jim is in agreement on the stock mil, but, as always, super logical and arguing for a reasonable 300-325 hp modded WRX for track and uber-peformance. The naked truth is that most guys build too much power and don't build a balanced sports car. The AJW crew were literally laughing out loud as many of their boys run 400 hp in street WRX's. We ALL agreed that a 165 hp imprezza build will be more fun than anyone really realizes and the ability to build one on target will be quite easy. The difficult part is getting a full tube framed car with modern suspension, paint-free body, and everything else for $9,900. We are confident we can do that, the exciting thing is that if you open the envelope from $15K to $20K, then all hell beaks loose on hp, brakes, suspension, and all-out performance. Still, we have to get the competent base line first, the foundation on which all these cars will be built... No compromise on the body and chassis. tough work going on right now. Also, new website should launch today with updated parts list on the 818 (but no final body images just yet.. still days/weeks away).

Woohoo! Time to get my F5 finger warmed up (that is, the button that refreshes the website. I don't have a specific finger for Factory Five). Thanks Dave as always for keeping us up to date.

[bobzdar]

have you ever driven a rotary powered car?

An rx-7 turboII.

[VTX]

I read this part...


... Also, new website should launch today with updated parts list on the 818...

...and went WOOOOHOOOO!!!

Then I read this part...


(but no final body images just yet.. still days/weeks away).

...and went NOOOOOOOOOOOOO!!!!!! ;)

Seriously, I hope it's days away. I can't wait to see this thing!

[Oppenheimer]

Your 15k or under build will not have konis, good tires or anything else unless you get the wrx for free.

It's fairly simple math.

818 kit is 9k
Wheel and tire package is 2k
Bilstein wrx setup is 2k

You're at 13k without even having a donor yet. A 2002-2006 wrx runs around 8k these days with under 100k miles - that's 21k. Add 50hp worth of tuning and exhaust and you're at $23,500 (using above quotes). That's with around 250hp and a good suspension and good tires. And nothing else.

I think you'll see 15k builds, but they'll be bare bones imprezza builds which won't have supercar performance (though quick for sure). I think it sounds great to say you're going to be as fast as a 150k ferrari for 15k, but there's no way in hell. Besides, 150k buys you a 430 these days, a 360 is less than half that.

If you buy a 'good' used WRX, you can sell off a lot of the parts and recoupe much of your donor spend. If you buy a wrecked donor, you'll have fewer parts to resell, but a lower price going in.

You will see $15K builds, with WRX power, which even stock will be amazing. Add $1K of engine mods, and watch out (where do you get 50hp requires a $2,500 spend? My math from the 'above quotes' = 60 hp for <$1K).

Will this require some sweat equity? Yes, it will. If we all had real equity to spend, would we just buy the Ferrari? Many of us would. Since most of us here don't, we'll invest what we have (free skilled labor). Carefully purchase a donor, spend the time to clean up and sell the unused parts, buy used wheels, etc.

In the end, we'll have something we can really be proud of, with an unequalled bang/buck ratio.

[bobzdar]

If you buy a 'good' used WRX, you can sell off a lot of the parts and recoupe much of your donor spend. If you buy a wrecked donor, you'll have fewer parts to resell, but a lower price going in.

You will see $15K builds, with WRX power, which even stock will be amazing. Add $1K of engine mods, and watch out (where do you get 50hp requires a $2,500 spend? My math from the 'above quotes' = 60 hp for <$1K).

Will this require some sweat equity? Yes, it will. If we all had real equity to spend, would we just buy the Ferrari? Many of us would. Since most of us here don't, we'll invest what we have (free skilled labor). Carefully purchase a donor, spend the time to clean up and sell the unused parts, buy used wheels, etc.

In the end, we'll have something we can really be proud of, with an unequalled bang/buck ratio.

Yup, sorry should be $1500 not $2500 - but I was $900 (does that include shipping?) low on the kit price, so $23,400. I think that's realistic but like I said whenever I've put down on paper what the car I'm putting together should cost, it has overrun by up to 50% and never come in under 20% over. Can you go cheaper than the $23k and still have wrx+ power? Probably, but then you'll also be dealing with a high mileage donor so factor in things like a new clutch, new brakes, possibly some new bushings or steering components, maybe CV joints etc. that will offset some of what you can make parting out the car. Still cheap and fast, but not super cheap and super fast. I don't think $15k for a well sorted car is realistic for anything more than base wrx (200hp ish) power. I think the nice thing is you can do the $15k build, get it running and then do some mods later on like upgraded wheels/tires, engine tuning etc, but all in you'll be in the mid 20's by the time you're out on the track challenging c5's and the like - which is still pretty good. But, like I said, a z51 C5 is the same price - though arguably not as cool or as fun to drive.

[skullandbones]

I don't know if this is typical but I thought it was a sweet deal for someone in the area. It's a not so badly damaged legacy. I think a donor like that and at that price ($2900) would give you a good start on a well performing hot rod. WEK.

I don't know if that link took or if you will have to cut and paste it.

http://www.crxsi.com/for-sale/seeimg.cgi?f=/for-sale/images/05-legacy-turbo-gt-wrx-subaru.1328827690.4.big.jpg&w=300&h=225&a=05%20legacy%20turbo%20gt%20WRX%20Subaru

[Xusia]

The Ferrari I get, but a C5? I'm not impressed in the slightest. My impression is that car is all about the engine, without a well sorted chassis to accompany it. I've driven a Mini Cooper S that would run rings around the C5 on the track (except on the straights, of course). I expect an 818 with a WRX engine would absolutely spank a C5 (except in top speed).

[el_jefe]

The C5 Z06 is a very well sorted and balanced chassis, and not just in tracks that let them stretch their legs. You run into them at auto-x all the time, doing very well. I would be hesitant to go after one in a heavy, underpowered FWD car like a cooper S

[shinn497]

i'm stoked to see this thread continuing on the performance questions. I met with jim and the subie guys at ajw yesterday and we were discussing this very thing. I want a stock wrx engine for all vehicle testing, but i also want an over-the-top mil for bragging rights and insane antics. I want the car to be too fast. Jim is in agreement on the stock mil, but, as always, super logical and arguing for a reasonable 300-325 hp modded wrx for track and uber-peformance. The naked truth is that most guys build too much power and don't build a balanced sports car. The ajw crew were literally laughing out loud as many of their boys run 400 hp in street wrx's. We all agreed that a 165 hp imprezza build will be more fun than anyone really realizes and the ability to build one on target will be quite easy. The difficult part is getting a full tube framed car with modern suspension, paint-free body, and everything else for $9,900. We are confident we can do that, the exciting thing is that if you open the envelope from $15k to $20k, then all hell beaks loose on hp, brakes, suspension, and all-out performance. Still, we have to get the competent base line first, the foundation on which all these cars will be built... No compromise on the body and chassis. Tough work going on right now. Also, new website should launch today with updated parts list on the 818 (but no final body images just yet.. Still days/weeks away).

dave just do it

700hp 818 yeah

[el_jefe]

Just give me 2" of clearance so I can fit the 3.0 H6 in, that's all I ask.

[RM1SepEx]

I have a friend who owns a Peter Farrel Supercars modified 1993 RX7TT. It has dyno verified 450 RWHP and weighs 2800 lbs. It has HUGE NASCAR sized Wilwood brakes. It's performance is breath taking... Autocrosses are amazing fun! All out speed, incredable... 165 in 5th!

There is no reason why we can't expect a warmed over WRX build to approach that car's performance, (except all out speed) you just need 290 WHP and the 818 will have much better torque/lbs. The stock WRX brakes should result in eye bleed braking with so much less mass to stop.

350 crankshaft HP would do it, and I'm sure someone has plans for more than that! I'll be happy with 200+ at the wheels with a good LSD added.

[StatGSR]

C5 non z06 vetts have not impressed me on the track at all... maybe its just the drivers (as it will always be since we are all not the stig), but they were constantly in the way of my 131whp Integra, which shy of a set of 205 Azenies, some now 7 year old $650 (when new) coilovers, a Type r transmission, and some sweet brake pads, is stock and full weight (2667lbs plus 200lb driver).... hell when my instructor drove my car, he was working the crap out of a C6 z06 in the twisties...

i wouldn't worry about C5s even with an RS motor in an 818, so long as you can atleast sorta drive...

Keep in mind, just because you have the fastest car AT the track, doesn't mean you have the fastest car ON the track... This will hold true, time and time again....

[bobzdar]

C5 non z06 vetts have not impressed me on the track at all... maybe its just the drivers (as it will always be since we are all not the stig), but they were constantly in the way of my 131whp Integra, which shy of a set of 205 Azenies, some now 7 year old $650 (when new) coilovers, a Type r transmission, and some sweet brake pads, is stock and full weight (2667lbs plus 200lb driver).... hell when my instructor drove my car, he was working the crap out of a C6 z06 in the twisties...

i wouldn't worry about C5s even with an RS motor in an 818, so long as you can atleast sorta drive...

Keep in mind, just because you have the fastest car AT the track, doesn't mean you have the fastest car ON the track... This will hold true, time and time again....

http://nasachampionships.com/pdf/2011/Group%20I%20Sunday%20Results.pdf

NASA time trial championships tell a different story. C5's comprise a good portion of the faster classes. The whole punt of that its to set a fast lap time and they appear to be excellent for that purpose.

As an aside, my wife has an 07 Cooper S, fun car but would get decimated by a c5 on anything but an autocross track. I've driven one and they are fast.

[Evan78]

Even in autocross, a C5 will trounce a mini cooper if the driver skill is equal.

C5 non Z06 is in A Stock
Mini Coopers are in H, D, or C Stock depending on edition.

For those not familiar with the classes, A is faster than B and so on down the alphabet.

http://www.moutons.org/sccasolo/Lists/2011/stockc.html

[Niburu]

An rx-7 turboII.
then you should know what it's like having lots of horsepower and not so much torque
I've had 2 FC's and a FD
Having driven my FD and then my friends FD with an LS-1 swap with about the same hp as my FD but WAY more torque.
His car was way faster off the line, if he didn't spin the tires to hard.

[bobzdar]

then you should know what it's like having lots of horsepower and not so much torque
I've had 2 FC's and a FD
Having driven my FD and then my friends FD with an LS-1 swap with about the same hp as my FD but WAY more torque.
His car was way faster off the line, if he didn't spin the tires to hard.

Not so much lack of torque but lack of boost off the line. You have to build boost to make power in a turbo car and it's tough to do in a manual trans car sitting stationary.

[StatGSR]

http://nasachampionships.com/pdf/2011/Group%20I%20Sunday%20Results.pdf

NASA time trial championships tell a different story. C5's comprise a good portion of the faster classes. The whole punt of that its to set a fast lap time and they appear to be excellent for that purpose.


not knowing the specifics on each class, there are many good things about C5s especially if they are prepared well, great power, good chassis, and relatively cheap for what you get. doesn't mean the bone stock ones you see at HPDEs everywhere driven by the guy having a midlife crisis is going to be a fast car around the track. Again, there is a difference between a fast car AT the track, and a fast car ON the track. Bad Drivers have been making fast cars slow and good drivers have been making slow cars fast for decades. just seems that outside of the competitive level (see HPDE) there are a lot of bad drivers driving C5s/C4s

[StatGSR]

Not so much lack of torque but lack of boost off the line. You have to build boost to make power in a turbo car and it's tough to do in a manual trans car sitting stationary.

that's just the reason why there is no torque.... you have to make torque over time to make power, you need to have a load to make boost, boost makes more torque, which in turn makes more power.... a piston moving down in a cylinder produces only torque, the continued production of torque over time is how one defines power, if the engine doesn't make torque, it cannot make power, period....

[bobzdar]

that's just the reason why there is no torque.... you have to make torque over time to make power, you need to have a load to make boost, boost makes more torque, which in turn makes more power.... a piston moving down in a cylinder produces only torque, the continued production of torque over time is how one defines power, if the engine doesn't make torque, it cannot make power, period....

If an engine doesn't spin, it doesn't make power either. You need both torque AND rpm, it's the combination that provides power. You can have 1000ft lbs of torque but if you can only make it at 1rpm, you don't have much power and it will get destroyed by an engine that makes 100ft lbs of torque at 10,000 rpm. Torque magnitude is meaningless, it's torque times rpm that determines power, and this is the only number that's meaningful for comparison.

[PhyrraM]

Torque magnitude is meaningless, it's torque times rpm that determines power, and this is the only number that's meaningful for comparison.

Only if the gearbox ratios is 100% perfect at all times for all situations. Once you loose a theroetical optimum for a situation torque again has some meaning.

[Evan78]

If an engine doesn't spin, it doesn't make power either. You need both torque AND rpm, it's the combination that provides power. You can have 1000ft lbs of torque but if you can only make it at 1rpm, you don't have much power and it will get destroyed by an engine that makes 100ft lbs of torque at 10,000 rpm. Torque magnitude is meaningless, it's torque times rpm that determines power, and this is the only number that's meaningful for comparison.What if I have a CVT that can handle 1,000 ft/lbs and has an EXTREMELY wide gear ratio range? ;-)

[Xusia]

Two things:

1. My comment about the Mini Cooper S wasn't to suggest it's a faster car. It's woefully under-powered compared to any Corvette, and lap times are often HP dependent (driver skill being equal). My comment was about the handling. The C5 is "OK" in the handling department in stock form, but "OK" doesn't cut it for me. The 818 should be far better, and won't be as under-powered as the Cooper S. Based on what I've seen mild Roadster builds do, the 818 should spank a C5 with even a stock WRX engine.

2. At any given RPM, the engine that makes more torque at that RPM will produce more HP (since torque*RPM=HP), so obviously BOTH torque and RPM matter. So does the rate at which the RPMs climb. An engine that can build revs faster, and therefore get to peak HP faster, will out accelerate an engine with the same torque and HP numbers that builds revs slower (assuming the same peak HP at same RPM). It's all about design choices and trade offs. High HP at high RPM are engine characteristics typically best suited for the track. More torque lower in the RPM range so that low RPM HP output is greater (resulting in lower peak RPM, and sometimes lower peak HP as well), are typical engine characteristics for the street because it makes the car easier and more comfortable to drive in a "civilized" manner (as you would around town). Based on what he has said, Bob seems like a track guy to me, so it's not surprising he is talking about high HP at high RPMs. I'm going to drive mine mostly on the street, so that's not what I want. Neither approach is wrong. They are just different approaches for different uses. :)

[StatGSR]

You can have 1000ft lbs of torque but if you can only make it at 1rpm, you don't have much power and it will get destroyed by an engine that makes 100ft lbs of torque at 10,000 rpm. Torque magnitude is meaningless, it's torque times rpm that determines power, and this is the only number that's meaningful for comparison.

tell that to the guys make engines for the container ships... cause obviously an engine that only rotates at 100rpm couldn't possibly be making much torque, cause its not like torque is important for moving things......

fun facts... http://www.gizmag.com/go/3263/
this engine makes 108,920hp at 102rpm.... as impressive as that is guess what is more awesome... at that same rpm, it makes 5,608,312 ft-lbs of torque....


max hp is meaningless unless you have a CVT, its always been about the area under the curve... and if you can't maintain torque as rpm increases, then you can't maintain power.

hell dude, I'm a honda guy, i love low torque, high reving cars. but they still get all their power by maintaining torque to higher revs (lots of IC engines cannot maintain torque at higher revs), and can still move quickly by having larger torque multipliers with the gears and final drive then other naturally high torque cars....

i feel like you think torque is constant with changes in rpm, and that's obviously not the case... things with low torque need shorter gears to effectively make more torque to move the same object at the same rate. its all give and take...

[StatGSR]

High HP at high RPM are engine characteristics typically best suited for the track.

tell that to the guys running the Audi R10 in Le Mans.... they seamed to be doing pretty well for a while there....

[Xusia]

LOL - hence the reason I used the word "typically." To each his own... :D

[shinn497]

Two things:

At any given RPM, the engine that makes more torque at that RPM will produce more HP (since torque*RPM=HP), so obviously BOTH torque and RPM matter. So does the rate at which the RPMs climb. An engine that can build revs faster, and therefore get to peak HP faster, will out accelerate an engine with the same torque and HP numbers that builds revs slower (assuming the same peak HP at same RPM). It's all about design choices and trade offs. High HP at high RPM are engine characteristics typically best suited for the track. More torque lower in the RPM range so that low RPM HP output is greater (resulting in lower peak RPM, and sometimes lower peak HP as well), are typical engine characteristics for the street because it makes the car easier and more comfortable to drive in a "civilized" manner (as you would around town).

Your assesment is mostly correct and makes sense for the real worl but I must point out some thing.

In Imperial units (HP, ft-pound, rpm) power = torque*rpm/5252 IF you notice on any dyno graph this is why power and hp cross at 5252 rpm. The actual value of hp and torque is dependant on the units so does it not mean much to say that the engine has more torque than hp

HP is kind of a meaningless number when you are talking about vehicle acceleration. Torque is king. You want high torque everywhere . IF you want hp to be useful look only at the ratio between hp and torque. Having a high hp means that your torque occurs later in the rpm range. This is why VTEC motors can post high hp by literally extending this range. This is usefull because at higher rpms the car is traveling at higher speeds. Furthermore engines with higher hp and therein higher torque in the rpm range tend to have broader flatter torwue curves.

The most useful engine, bar none, is one with a broad, high, flat torque curve. This give you the largest period of sustained acceleration.

With that said this does not translate to a high hp engine. Consider two engines with the same hp and torque. However one has a broad torque curve and the other merely has peak later in the rpm band. The one with the broader torque curve would win AT ANYTHING. However, the two engines would be rated exactly the same. This is why, to truly know the performance of an engine, you must look at the torque curve.

[shinn497]

If an engine doesn't spin, it doesn't make power either. You need both torque AND rpm, it's the combination that provides power. You can have 1000ft lbs of torque but if you can only make it at 1rpm, you don't have much power and it will get destroyed by an engine that makes 100ft lbs of torque at 10,000 rpm. Torque magnitude is meaningless, it's torque times rpm that determines power, and this is the only number that's meaningful for comparison.

An engine with high torque and low rpms would be incredibly useful it given the propwer gear box (one withlike 1000 gears). In the real world it would quickly accelerate out of this rpm range.

However, for a large vehicle, this is absolutely useful. The mass prevents this acceleration and keeps the revs low. This is why trucks and large vehicles are often diesel powered. They can make large torque at low revs. These vehicles are too massive to worry about moving out opf the ideal rev range.

RPM doens't provide power. This is why hp is kind of a misnomer. Just think of it realistically. Any car traveling at a high speed must have a high rpm to the the wheel diameter relative to the drive shaft. You could have a torque low rpm engine in a normal car but consider the following.

V = r * w (V = velocity, r = wheel radius, w = angular velocity (rpm)).

If the engine is spinning at a low angular velocity it can't be traveling fast on normal sized wheels . You would have to increase the wheel size to compensate. If you used tormal sized wheels, the engine would quickly accelerate to a high rpm and redline. So lets say a diesel engine had a 800-3000 rpm rev range ( I don't know if this is true just guessing) but made high torque. It would quickly rev to 5000-7000 on normal sized wheels. Which means you would need to change gears twice as much and thereing have twice as many gears. I'm sure you guys could tell me the problems of overrevving an egninge, 20 gear gearboxes, and 40 inch wheels. Also mind you if you could get these parts out of some magic high strength material they would probabl;y be very heavy.

[shinn497]

Physic...you just need it

[Xusia]

You are correct about the formula. My intent was to note the relationship between the two, not the exact formula. Sorry if that was confusing or misleading to anyone.

As for torque is king, I agree, BUT I disagree that the higher torque engine always wins. The 2007 (I think) Yamaha R1 is an example of an engine with a comparatively low peak torque, but because of the engine design it can hit very high RPMs, and thus produces a comparatively high peak HP number. The Suzuki GSX-R1000 of the same year, was just the opposite. It produced monster torque, but had a lower RPM range and produced slightly less peak HP than the R1. By your argument, the Suzuki would win hands down, but that wasn't the case. Both bikes were very competitive on the track, and my 2004 ZX-10R (another torque monster; see my avatar) was beaten by the aforementioned R1 of a good riding buddy on the street (straight line acceleration) multiple times DESPITE my bike having way more torque (and like 2 less HP). For the record, we are approximately the same size and weight (although my bike weighed less, which should have given me an advantage), and my ZX-10R beat his previous R1 easily (which used a completely different engine design).

[bobzdar]

There are some very easy mathematical exercises you can do to prove one way or another which tells you more about an engine, the torque or the horsepower. If you look at torque values or curves alone (ie without rpm), you cannot determine anything about an engine. If you look at the horsepower curve (without rpm), you can.

Lets look at it mathematicaly, which will provide better acceleration in a car moving 60mph with 27" tall tires, one making 300 ft lbs of torque and operating at it's peak of 4000rpm or one making 200 ft lbs of torque and operating at it's peak of 8000rpm?

[bobzdar]

a 27" tire at 60mph will be turning at 672rpm.

Engine A operating at 4000rpm will need a 5.95 gearing reduction to turn 672rpm, so will be putting 300x5.95=1785 lbs ft of torque to the road

Engine B operating at 8000rpm will need a 11.90 gearing reduction to turn 672rpm, so will be putting 200x11.95=2380 lbs ft of torque to the road.

So, engine B will be accelerating faster despite having less torque. Now here's the part that shows the usefulness of power. 300x4000/5250=229hp for engine A. 200x8000/5250=305hp for engine B. 305/229=1.33. 2380/1785=1.33.

This is why power will tell you exactly how much potential work an engine can do if geared optimally. All you need to look at is the horsepower curve to tell how much potential work an engine can do. If you want to compare 2 engines, take both HP curves and divide the X axis (rpm axis) of each by their peak rpm (so peak HP is at 1 on both graphs) and overlay them. The one with more area under the HP curve can do more work. You cannot do that with the torque curve as you need the rpm information to tell you which engine can do more work. If I had posed the above scenario without the rpm the engines made their torque, you would not be able to tell which engine provided greater acceleration because you'd have no idea what gearing they'd need to move 60mph. Once you have the rpm information along with the torque value, you are no longer looking at torque but power.

[JRL]

Evidently those of you bashing the C5 have either never seen a well driven proper set up C5. You are delusional if you think you will "spank" them with a 200 + - HP 818.

[mekeys]

My expectation is to put it in "D" roll the windows up with the AC on and blast down I-10 at 70 MPH..

Mel

[carbon fiber]

anybody know where i can buy a good bench to race on? figured this would be the place... just kidding guys. on a serious note, there is one major factor missing in these discussions about engine size, hp, torque, revs, etc. and that is balance. a point dave made somewhere back there. i myself have fell prey to the more is better philosophy in the past and it's not always true. traction and stability controls can reel in a beast to a degree, but there is a point where you've turned a car that was supposed to handle well into a drag or top speed car. anything beyond 400 whp in this car as light as it is, will be a handful. the more power you make the more beefing up of all related components you will need, and probably (from my experience) will be working on the car more also. lot more fun to drive a fast balanced car than a wicked fast car that you can't control. having said that, i still expect to see a 500+ hp 818 before it's over!

[StatGSR]

My expectation is to put it in "D" roll the windows up with the AC on and blast down I-10 at 70 MPH..

Mel

FYI, Automatic transmission compatibility has yet to be confirmed.

[StatGSR]

Evidently those of you bashing the C5 have either never seen a well driven proper set up C5. You are delusional if you think you will "spank" them with a 200 + - HP 818.

average c5 + average c5 driver /= fast on the track..... average c5 + "good" driver = fast/quick on the track...

like i said, before, there were like 10 c5s at my last track day there was maybe 1 or 2 i didn't pass with my integra.... it just seems there are alot of sub par corvette drivers out there, but that doesn't really mean anything is wrong with the car, it just means there are alot of people out there afraid to really drive their own car...

[Xusia]

Like I said, I've been in a C5 and I'm not impressed. At all. As has been said, balance is key (at least to me), and the C5 just isn't. Apparently that puts me in the "delusional" camp. I've been called worse! :D

[carbon fiber]

have driven c5 stock and modded. stock=lots of body roll-geared towards comfort/modded=huge improvement and very balanced. also driven cadillac xlr with magnetic shock system=no body roll + should have been standard on the c5.

[JRL]

StatGSR - it's the gold chains around their neck :p

[JRL]

You are also talking about a design (C5) with 15 year old technology. Jump up a few years and see what you get.

[carbon fiber]

as long as it's rear wheel drive it's got potential. yes, i hate anything front wheel drive. before anyone starts hating, remember there are no fwd formula one cars for a reason.

[Xusia]

Because the rules prohibit that?

J/K! Although you are making an assumption as to why, that may - or may NOT - be correct. :D

[carbon fiber]

have driven both, know what I like. never seen front wheel drive supercar! seriously, to each his own.

[BipDBo]

The reason that the fastest cars are either rear wheel drive or AWD with most of the power routed to the rear wheels is that of physics. When you open the thottle to accelerate, weight shifts to the rear wheels, so that's where you want the traction. It's also no mistake that land animals are built this way. The hindlegs are more muscular and not as flexible side to side where as the front legs are lighter more nimble and flexible. The rear legs provide power while the front legs steer the animal. The only exception that I can think of to this is the bulldog but that's just an apostasy to all creation.

The only reason that some FWD drive can be quick is that they are compared to other front engine RWD cars of similar power. The engine is placed up front for crash protection. If you have the engine in the front, you can save a lot of weight by going FWD vs RWD. The 818 has both the power and the traction optimally in the rear. This is, as I the demonstrated by the example of animals, exactly as God intended.

[el_jefe]

I've made money off of suckers that underestimate FWD cars. Most of them had RWD or AWD. Not to say that I necessarily prefer them, but I look at the platform as a whole instead of the drivetrain.

[Flamshackle]

The 818 has both the power and the traction optimally in the rear. This is, as I the demonstrated by the example of animals, exactly as God intended.

This was gold hahaha... Divine drive and traction! I like it! ;)

[BipDBo]

I've made money off of suckers that underestimate FWD cars. Most of them had RWD or AWD. Not to say that I necessarily prefer them, but I look at the platform as a whole instead of the drivetrain.

I have no doubt about that. As I stated a FWD car will typically be lighter than a RWD equivalent, usually by at least 300#. Another reasonis weight distribution. If the car has most of its weight over the front wheels, it's optimum, for track purposes, to have the traction up front. If you've got a whole lot of power and you want to go drag racing, that's a different story. Also, when stock cars are prepped for track use, they may gain some weight under the hood in performance parts, but they loose it elsewhere on the car, further shifting the distribution forward. Therefore a front engine with RWD that has 30-40% of it's weight on the rear wheels is going to get spanked by a FWD car. Manufacturer's would do well to mave as much weight from under the hood, toward the rear of the car. I've been hoping for a while that Ford would develope a rear transaxle for the Mustang. The point I'm trying to make is that the whole compromise starts when the engine is placed in the front. When you can put the engine in the rear, you aree quickly on your way to optimal dynamics.

It's not quite as simple as I'm making it out to be though. There are a lot of new compromises to work with when moving the engine to the rear of the vehicle. There's a lot of pakaging issues with the mid-engine arrangement, so it's hard to imagine how to design anything except a 2 seat sportscar with a mid-engine. Also, crash worthiness is a huge issue. When there is a big mass of metal behind the occupants, the frame needs to be considerably stronger and therefore heavier to prevent that mass from crushing the occupants. I just hope that the 818 is being designed with this in mind.

[Niburu]

When there is a big mass of metal behind the occupants, the frame needs to be considerably stronger and therefore heavier to prevent that mass from crushing the occupants. I just hope that the 818 is being designed with this in mind.

This is the very least of our worries, if FFR does one thing well, it's chassis design.

[Nuul]

HP: 250-325 crank
Weight: 2200 with engine and wet
0 - 60: 4.5
0 - 100: Not sure
1/4 Mile: Not sure
Top Speed: Ludicrous speed (http://i.imgur.com/hZoUc.png)
70 - 0 Braking: Quick enough to give me a seat belt bruise.
Lateral G's: 1.1 on racing tires
MPG: 15 MPG or so since this isn't a daily driver

[shinn497]

You know I heard it mentioned by jim that the stated weight of 1800 pounds is WET and with an average driver.

[el_jefe]

I wonder if this is going to be so light that a lot of aero downforce is going to be necessary to really get everything out of it on the track.

[Evan78]

You know I heard it mentioned by jim that the stated weight of 1800 pounds is WET and with an average driver.I seem to remember him specifying something, but I thought it was wet without driver. Lighter sounds better, so it doesn't seem like great marketing to talk about car weight WITH driver when everyone else talks weight without driver.

[Evan78]

I wonder if this is going to be so light that a lot of aero downforce is going to be necessary to really get everything out of it on the track.What do you mean? Why would a light car need aero any more than a heavy car? I would think just the opposite since given equal tires, etc, a light car is going to have higher limits than a heavier car.

[shinn497]

Evan this is about simple physics. A heavier car has more weight pressing down on the tires and thus can take more lateral force without slipping. A lighter car requires less force to turning but, if at speed, is more prone to loss lf grip. This is why aerodownforce is so important. ]

Watch the top gear episode on the caparo t1. That car is so light that it did not handle properly until it was above 50 mph .

**physicsy answer** The tire compound determines the coefficient of static friction but not the normal force between thr tire and the road. The maximum force before slippage occurs is the product of the two. Of course lighter cars require less force to turn.

[Twinspool]

And THAT gentlemen, is why all autocross courses are dominated by physicists in heavy cars. ;-)

[VTX]

Hmmm, I'm not an expert on vehicle physics, so I could be completely off base, but I would think that a heavier car would also have more lateral inertia in a turn as well. I would think that would cause some amount of counteraction to the heavier weight pressing down on the road.

Assuming that is correct, then the question would be: is that counteracting force less than, equal to, or greater than the extra weight of the car pressing down on the road? I would imagine speed would also be a factor in this.

Any vehicle physics experts want to comment on this?

[bromikl]

The Caparo T1 video shows there's no such thing as too light. :D

Enjoy. http://www.topgear.com/uk/videos/scorching-t

[BipDBo]

The chief concept that dictates how a car will do on the skidpad is the static friction coefficient of the tires on the pavement. This is defined as the ratio between the horizontal force (due to lateral acceleration) divided by the vertical force (due to gravity). It is defined at the point where the greatest horizontal force is applied before it starts to slide. A 4000# car will have twice as much vertical (gravity) force on the tires as a 2000# car. It will also, given the same turn at the same speed, have twice as much horizontal force. The proportions are therefore the same so theoretically, the 4000# and 2000# cars should be able to perform the same on the skidpad, but in reality, this doesn't really work out.

http://en.wikipedia.org/wiki/Friction

Theoretically, the static friction coefficient is specific to the two materials in contact (rubber & pavement) and independent of the pressure applied to the materials. This is per Amonton's first and second laws, which in my opinion, should be called suggestions rather than laws because they don't usually work so cleanly with real experiments. The friction coefficient, theoretically should match the skidpad g. A car with rubber and pavement with a friction coefficient of 1.1 should be able to pull 1.1 g. If you measured the static friction coefficient with a set of weights, a slab of asphalt and a slab of rubber, though you would find a much higher number than a car can typically pull in g. You may find a coefficient of around 1.5. The real world, involving rolling tires and a car swaying on suspension, introduces many factors that reduce the allowable horizontal force. Not the least of which of these factors is that the proportion of horizontal force to vertical force is not the same across all of the points of contact between rubber and road. The points with the largest proportions will start to slip first. For many reasons, particularly of tire dynamics, which are difficult to briefly describe, these factors will tend to affect heavier cars proportionately higher than lighter cars.

Even when you take aerodynamic downforce completely out of the equation, lighter cars tend to do better on the skidpad than heavier cars. Anecdotally, karts have no significant aero downforce, and they pull around 1.4 g. Aerodynamic downforce, because of simple proportions of vertical and horizontal forces, will improve the skidpad performance of a lighter car much more effectively than a heavier car. Therefore, a light car like the 818, stands a lot to gain from some aero downforce.

http://www.modified.com/news/0708_sccp_lateral_g_skidpad_testing/viewall.html

[Nuul]

You know I heard it mentioned by jim that the stated weight of 1800 pounds is WET and with an average driver.

Ah, I didn't know that. I was operating under the assumption that the 1800 was sans engine, gas and driver.

[Evan78]

And THAT gentlemen, is why all autocross courses are dominated by physicists in heavy cars. ;-)LOL, couldn't have said it better myself.

shinn497 - I played dumb a bit because I'd rather know what someone's thought process is before I jump in with a contrary statement.

[BipDBo]

This is the new Roding Roadster, perhaps the closest thing I've seen to the 818. It has the same mid engine, RWD configuration and approximate weight distribution. It has a very similar wheel base. At 2090# and 320 hp, it's a little bit heavier and a little it more powerful than an 1800# 818 with a 265 hp WRX engine, so it has nearly the same power/weight ratio. Take a look at the press release for some of its specs. I'd say that whatever this can do, the 818 should be able to do, maybe even a little better.
8227
http://www.autoblog.com/2012/03/07/roding-roadster-is-fit-for-a-role-in-the-avengers/#continued

[BrandonDrums]

Evan this is about simple physics. A heavier car has more weight pressing down on the tires and thus can take more lateral force without slipping. A lighter car requires less force to turning but, if at speed, is more prone to loss lf grip. This is why aerodownforce is so important. ]

Watch the top gear episode on the caparo t1. That car is so light that it did not handle properly until it was above 50 mph .

**physicsy answer** The tire compound determines the coefficient of static friction but not the normal force between thr tire and the road. The maximum force before slippage occurs is the product of the two. Of course lighter cars require less force to turn.

When can we get Bill Nye to come in as a moderator? I'm really tired of these horrible 9th century answers. You're leaving out that a heavier car will exert more lateral force because it has more inertia.

Thus it will break loose sooner because the static and kinetic coefficient of friction of a malleable material such as tire compound will actually fall a little with heat, stress and deformation. The normal force does increase the grip in the system but grip doesn't increase at a linear rate with the addition of weight.

Downforce simply increases the normal force a vehicle exerts when moving thusly improving the grip while not having to increase vehicle weight. However, increasing that force also wears tires out faster. On a racecar, there's a balance between maximizing tire life, max speed and handling at all times and is a VERY common topic of discussion among F1 teams for each and every track.

[305mouse]

I'll revert back to another Top Gear episode. The first Koenigsegg couldn't stay planted. Top Gear stated a spoiler would help the car tremedously. Can't recall if TG made the spoiler or just the recommendation. Koenigsegg made a spoiler and referred to it as the Top Gear spoiler. The car handled much better through the turns and straight aways. So for the track, more downforce will be obviously wanted. For the DD roadster, probably not. We will have to wait till the thing is built and tested. I love speculation.

[16g-95gsx]

They also completely overlook the effects of camber and contact patch. Let alone additional suspension component inputs that aid in normal forces on the tires. Hell, I don't even see comments about roll centers.


When can we get Bill Nye to come in as a moderator? I'm really tired of these horrible 9th century answers. You're leaving out that a heavier car will exert more lateral force because it has more inertia.

Thus it will break loose sooner because the static and kinetic coefficient of friction of a malleable material such as tire compound will actually fall a little with heat, stress and deformation. The normal force does increase the grip in the system but grip doesn't increase at a linear rate with the addition of weight.

Downforce simply increases the normal force a vehicle exerts when moving thusly improving the grip while not having to increase vehicle weight. However, increasing that force also wears tires out faster. On a racecar, there's a balance between maximizing tire life, max speed and handling at all times and is a VERY common topic of discussion among F1 teams for each and every track.

[BrandonDrums]

I'll revert back to another Top Gear episode. The first Koenigsegg couldn't stay planted. Top Gear stated a spoiler would help the car tremedously. Can't recall if TG made the spoiler or just the recommendation. Koenigsegg made a spoiler and referred to it as the Top Gear spoiler. The car handled much better through the turns and straight aways. So for the track, more downforce will be obviously wanted. For the DD roadster, probably not. We will have to wait till the thing is built and tested. I love speculation.

Well, a road-legal supercar rarely makes so much downforce that it's an issue for any significant tire wear. I just used the F1 example to highlight the exaggerated effects of downforce as an F1 car makes more than it's own weight in downforce at just 100mph and wears much softer tires than a street car.

Road cars can weigh over 2 tons and rarely go over 100mph nor are driven around hairpin turns at 80mph so weight is a much bigger stressor on tire wear than downforce. I think an adjustable wing even on the DD would be super beneficial on the 818.

The main point was that weight spoils handling. A lighter car handles better than a heavier one all other things being equal, downforce isn't needed to improve lateral G's.


They also completely overlook the effects of camber and contact patch. Let alone additional suspension component inputs that aid in normal forces on the tires. Hell, I don't even see comments about roll centers.

As 16g-95gsx pointed out, you also have to consider contact patch to vehicle weight ratio and increased dynamic contact patch as a lighter vehicle rolls less than a heavier one (outside of fancy suspension tech), yet another variable that goes into what makes lighter cars handle and grip better than heavier ones.

More wiki excerpts!

http://en.wikipedia.org/wiki/Friction#Coefficient_of_friction


While it is often stated that the COF is a "material property," it is better categorized as a "system property." Unlike true material properties (such as conductivity, dielectric constant, yield strength), the COF for any two materials depends on system variables like temperature, velocity, atmosphere and also what are now popularly described as aging and deaging times; as well as on geometric properties of the interface between the materials. For example, a copper pin sliding against a thick copper plate can have a COF that varies from 0.6 at low speeds (metal sliding against metal) to below 0.2 at high speeds when the copper surface begins to melt due to frictional heating. The latter speed, of course, does not determine the COF uniquely; if the pin diameter is increased so that the frictional heating is removed rapidly, the temperature drops, the pin remains solid and the COF rises to that of a 'low speed' test.

The part about the "geometric properties of the interface between the materials" is precisely 16g-95gsx's point about camber, roll center etc. A heavier car with the same camber etc. as a lighter one will make the wheel move about the tire sidewalls more deforming the contact patch in addition to leading over more which reduces dynamic negative camber. Aside from the material of the tire getting heated and stressed more, the mere geometry of the tire's contact patch is more compromised during a turn than that of a lighter vehicle.

Modern, heavier sports cars employ some fancy suspension technology to counter that. In the end, it's way cheaper and more effective to reduce vehicle weight which I believe is why we are all here posting away on the 818 forum. We all want a cheap, fast car and that's accomplished by reducing weight rather than expensive fancy engine and suspension technology.

I apologize for becoming a physics nazi of sorts but bad logic when applied to cars just bugs me something special and has no place on this forum. It's worse than going off-topic IMHO.

To get this thread back on point, because the 818 is lighter, it's going to handle darn well. Increasing the power to weight ratio will force us to get stickier tires in the back though, but not as much as one of the front-engine FFR cars. I expect the 818 to kick ***.

[BipDBo]

More wiki excerpts!

http://en.wikipedia.org/wiki/Friction#Coefficient_of_friction


...

To get this thread back on point, because the 818 is lighter, it's going to handle darn well. Increasing the power to weight ratio will force us to get stickier tires in the back though, but not as much as one of the front-engine FFR cars. I expect the 818 to kick ***.

I agree with the Wikipedia entry that friction coefficient should be thought of more as system property than a material property. That's a very good way of stating it. Most of that entry, however is refering to the kinetic friction coefficient, which deals with friction between two surfaces after they have started to slide. Tire grip is dictated by the static friction coefficient, unless of course, you're drifting.

Anyway, it looks like we're all back in aggreement that lighter is better.

[Oppenheimer]

...Most of that entry, however is refering to the kinetic friction coefficient, which deals with friction between two surfaces after they have started to slide. Tire grip is dictated by the static friction coefficient, unless of course, you're drifting.

I don't claim to be an expert, but wouldn't any rolling, weighted tire, attached to a vehicle that is experiencing some sort of acceleration (forward, backward, or to the side) be more an example kinetic friction than static? (even if not drifting)

Aren't tires that are 'gripping' (not just rolling along straight and steady) always sliding to some degree? A differential exists so the tires on one side can spin at different rate than tire on other side, when going around a turn. A tire has width, so while turning, the rubber on one side of tire wants to spin at a slight difference in speed from the rubber on the other end, but can't. So there is some 'sliding' going on. The rear tires are also fixed, they can't 'turn in' to match the arc of turn. Even the front tires aren't both perfectly aligned to the same arc. There is some toe, and that toe varies based on speed, load, all sorts of things. Point is the two tires aren't perfectly pointed in the same direction all the time. So more micro-sliding going on.

I sorta have this picture in my head that the tires are constantly squirming and micro-sliding, playing give and take back and forth, the whole time they are under any sort of acceleration force (even when seat of pants feels totally planted and like on rails). Is that not more kintetic friction than static?

[BipDBo]

I don't claim to be an expert, but wouldn't any rolling, weighted tire, attached to a vehicle that is experiencing some sort of acceleration (forward, backward, or to the side) be more an example kinetic friction than static? (even if not drifting)

Aren't tires that are 'gripping' (not just rolling along straight and steady) always sliding to some degree? A differential exists so the tires on one side can spin at different rate than tire on other side, when going around a turn. A tire has width, so while turning, the rubber on one side of tire wants to spin at a slight difference in speed from the rubber on the other end, but can't. So there is some 'sliding' going on. The rear tires are also fixed, they can't 'turn in' to match the arc of turn. Even the front tires aren't both perfectly aligned to the same arc. There is some toe, and that toe varies based on speed, load, all sorts of things. Point is the two tires aren't perfectly pointed in the same direction all the time. So more micro-sliding going on.

I sorta have this picture in my head that the tires are constantly squirming and micro-sliding, playing give and take back and forth, the whole time they are under any sort of acceleration force (even when seat of pants feels totally planted and like on rails). Is that not more kintetic friction than static?

I don't think so. For the most part, the conditions that you state I'll refer to as "geometric conflicts," which you argue would cause some sliding to occur. I argue, would not typically cause sliding to occur for these reason. Firstly, under most conditions, these conflicts are very small. Secondly, tires are very flexible. The tread will deform , stretch and compress to overcome these small geometric conflicts and stay planted on the road. In some cases, these conflicts become too large for the tire tread to overcome. One case would be a very tight turn, especially when you have wide tires. No matter how slow you go, you can hear those tires squealing.

The most important thing to know about kinetic and static friction coefficients is that the kinetic friction coefficient is always much lower than the static coefficient. For example, if you need to push a large piece of furniture across the floor, it takes a bit less force to keep the thing from sliding than it did to "break it free" and start the slide. This is why ABS breaks are very important. They keep the tires from "breaking free" from the static coefficient and sliding. ABS not only keeps the car under control, but stopping distance is also greatly reduced when compared to simply locking up the brakes. This is a result of the fact that the kinetic friction coefficient is lower than the static coefficient.

These geometric conflicts, however, still pose problems even when the static friction has not been broken. Since the tire tread is deforming in different directions, the effective horizontal friction forces applied to the tread are not equally proportional to the vertical gravity forces, of which I spoke of in an earlier post. These geometric conflicts, will therefore cause some points along the tread to get to or possibly even exceed the static friction coefficient, even if the total or average ratio of centripetal force / gravity force does not exceed the friction coefficient. In this case, some of tread will begin to slide prematurely, and thus diminish skidpad performance. A light car could potential wear treads half as wide as a car twice its weight. With a more narrow tire, these geometric conflicts are reduced, therefore improving the cars ability to get a skidpad rating closer to the tire's theoretical fiction coefficient.

[BrandonDrums]

I don't claim to be an expert, but wouldn't any rolling, weighted tire, attached to a vehicle that is experiencing some sort of acceleration (forward, backward, or to the side) be more an example kinetic friction than static? (even if not drifting)

Aren't tires that are 'gripping' (not just rolling along straight and steady) always sliding to some degree? A differential exists so the tires on one side can spin at different rate than tire on other side, when going around a turn. A tire has width, so while turning, the rubber on one side of tire wants to spin at a slight difference in speed from the rubber on the other end, but can't. So there is some 'sliding' going on. The rear tires are also fixed, they can't 'turn in' to match the arc of turn. Even the front tires aren't both perfectly aligned to the same arc. There is some toe, and that toe varies based on speed, load, all sorts of things. Point is the two tires aren't perfectly pointed in the same direction all the time. So more micro-sliding going on.

I sorta have this picture in my head that the tires are constantly squirming and micro-sliding, playing give and take back and forth, the whole time they are under any sort of acceleration force (even when seat of pants feels totally planted and like on rails). Is that not more kintetic friction than static?

You're exactly right and that movement gets exaggerated when a vehicle is heavier in both static (no slip, rolling grip) and kinetic (slip/slide relationship), a sidewall bulging more is just the most obvious effect of that which happens even when the car is sitting still. Tread gets separated and the material gets stretched and compressed as weight increases and more heat is generated even when rolling straight down the road. That makes the material weaker and reduces it's grip both on the static and kinetic side of things.

[bobzdar]

I agree with the Wikipedia entry that friction coefficient should be thought of more as system property than a material property. That's a very good way of stating it. Most of that entry, however is refering to the kinetic friction coefficient, which deals with friction between two surfaces after they have started to slide. Tire grip is dictated by the static friction coefficient, unless of course, you're drifting.

Anyway, it looks like we're all back in aggreement that lighter is better.

I'm not aware of any tire that makes optimal grip without sliding. If you want a basic understanding of how load, tire size, slip angle, contruction type etc. affects grip of a tire, try this paper:

http://media.wiley.com/product_data/excerpt/19/04713546/0471354619.pdf

The relevent section regarding grip vs. % sliding is attached.8242

There are also sections regarding load vs. lateral grip, in short it depends on tire size and construction but there's always a point where grip falls off once you put too much weight on the tire and there's a proper tire size for the load you're applying to get maximum grip, and it's not linear. This tells you nothing about transitional handling and it's always easier to get a lighter weight to change direction.

[RM1SepEx]

Tires work in a weird area that is actually both static and sliding, they have a maximum slip angle that can't be exceeded before they go to sliding friction, too tough to mechanically model for us mere mortals w/o big time computing power, and yes each rubber block sees a different situation

The width of a tire never enters the F=uN equation (frictional force equation where u is the coefficient of friction and N is the normal force due to gravity

what happens is too much of a load on a wide tire means it doesn't reach adequate temperature, or runs cooler and lasts longer
too narrow a tire overheats too quickly wears quickly, gets greasy as it overheats
you can both over and under tire a car. I expect that the 818 won't need any bigger than 225-245 tires and they will run at 20-25 PSI
downforce would help both heavy and light cars under cornering and braking, it causes add'l drag reducing eff. and top speed

wheel width to tire width is very important to keep the tire profile properly oriented to the tread blocks/road surface

[BipDBo]

I'm not aware of any tire that makes optimal grip without sliding. If you want a basic understanding of how load, tire size, slip angle, contruction type etc. affects grip of a tire, try this paper:

http://media.wiley.com/product_data/excerpt/19/04713546/0471354619.pdf

The relevent section regarding grip vs. % sliding is attached.8242

There are also sections regarding load vs. lateral grip, in short it depends on tire size and construction but there's always a point where grip falls off once you put too much weight on the tire and there's a proper tire size for the load you're applying to get maximum grip, and it's not linear. This tells you nothing about transitional handling and it's always easier to get a lighter weight to change direction.

This thread is getting really challenging and I like it.

That graph refers to tire slippage occuring as a result of axle torque from acceleration or breaking rather than slippage due to cornering. Nonetheless, it illustartes that some parts of the tire start slipping before others, causing the tire to ease into a slipping condition transitioning from static to kinetic friction, rather than suddenly jumping into it like a piece of furniture pushed across a floor. I was simplifying the concept a bit, but you and RM1SepEx are right that a tire grips and slips at the same time. This is not a simple concept. I'll have to read that paper later. Looks interesting.

[PhyrraM]

......you can both over and under tire a car.......

This is the part that has the most merit in the real world of street driving. It applies to both lateral acceration and to "normal" acceleration and deceleration. 245+ section tires will likely not be advantageous in any way (other than looks - for some) at the target weight of 1800 pounds. I'm *guessing* that the stock WRX widths of 205 or 215 will likely be ideal, with very slight improvements in some areas (with a corresponding loss in others) going up in size from there.

[el_jefe]

This is the part that has the most merit in the real world of street driving. It applies to both lateral acceration and to "normal" acceleration and deceleration. 245+ section tires will likely not be advantageous in any way (other than looks - for some) at the target weight of 1800 pounds. I'm *guessing* that the stock WRX widths of 205 or 215 will likely be ideal, with very slight improvements in some areas (with a corresponding loss in others) going up in size from there.


Laterally maybe, but don't discount acceleration and deceleration. Even at stock WRX power levels, 205 or 215's will be insufficient, unless you are running slicks or don't believe in hard acceleration or braking.

[BrandonDrums]

Laterally maybe, but don't discount acceleration and deceleration. Even at stock WRX power levels, 205 or 215's will be insufficient, unless you are running slicks or don't believe in hard acceleration or braking.

That's what I'm sayin'

More tire patch almost always yields more grip. Almost because snow/ice and wet messes things up.

the 818 would likely do well with just 245's in the rear, if you're worried about heat don't be. A car that light can run 22 psi. My bud's MK3 roadster has 285's in the back with 24 psi in them for the street and 22 for the drag strip and he's running Nitto DOT slicks practically on a daily driver. He got way more grip bumping up to 285's from 255's too and the MK3 only weighs about 2100 lbs I believe.

Contact patch is contact patch. If having more contact with the ground reduced grip, then we need to tell the US military to retrofit their tanks with skinny tires instead :-P

[kach22i]

This is the new Roding Roadster, perhaps the closest thing I've seen to the 818. It has the same mid engine, RWD configuration and approximate weight distribution. It has a very similar wheel base. At 2090# and 320 hp, it's a little bit heavier and a little it more powerful than an 1800# 818 with a 265 hp WRX engine, so it has nearly the same power/weight ratio. Take a look at the press release for some of its specs. I'd say that whatever this can do, the 818 should be able to do, maybe even a little better.
8227
http://www.autoblog.com/2012/03/07/roding-roadster-is-fit-for-a-role-in-the-avengers/#continued
Heck of a find, sure fits in the 818 box.

I'm surprised that the rear overhang is not more generous, maybe proving our template was somewhat exaggerated in this area.

The normal seats (not super reclined and low) look pretty good and close to stock seat proportions.

I do take issue with the high hood level, makes the car look front engined.

The red and black or red and carbon fiber two-tone color scheme is tacky. Maybe the car was too conventional looking or bland without such gimmickry.

The rear view is my favorite angle, reminds me of Vman's Vantage.

[VTX]

kach, I agree on the black red two tone. Definitely tacky. I'd like to see it without that personally. Otherwise looks nice.

[RM1SepEx]

Contact patch is contact patch. If having more contact with the ground reduced grip, then we need to tell the US military to retrofit their tanks with skinny tires instead :-P

Contact patch is actually not in the equation... F=UN note, no area Frictional Force capability, coef of friction and Normal force only...

Tanks have tracks for use in wet, or soft areas
Jeeps always had skinny tires...

[SkiRideDrive]

For those that would like an introduction to vehicle dynamics, I would suggest Carrol Smith's "Tune to Win." It will help with learning how tires work and the effects of weight and down-force on handling.

[el_jefe]

Contact patch is actually not in the equation... F=UN note, no area Frictional Force capability, coef of friction and Normal force only...

Tanks have tracks for use in wet, or soft areas
Jeeps always had skinny tires...

Tune for the chassis/powertrain or conditions. Skinny tires are great for mud, mileage, and some types of snow, wide tires are better for rock (maximize contact patch) or sand (better float)

I'm having flashbacks to the technician vs engineer arguments I used to have, where the engineers would use math to say that something should work, and the tech would reply based on experience why it wouldn't.

Then with our powers combined, we would find a way to make it happen.

[Smythe]

Not sure if his has been discussed or not but what about the front wheel width?

With all the weight in the rear I think you would be more prone to understeer as the front struggles to gain traction.

Those with a WRX should know exactly what I'm talking about. It is notorious for pushing even in a mild sweeping corner. I run 245's on my WRX and 225's on my Miata, both had an incredible improvement but that's more to the tire compound than the wheel width.

I understand the discussion around contact patch and the F=uN equation. The force is distributed over the contact area, mathematically that pressure between the road and the tire should not matter because as the contact patch increased the force decreases and vice versa. Yet, everything else equal a larger contact patch is desired. Unfortunately I don't have the time right now to research why. As it is I'm procrastinating a paper on strategic marketing and branding.

[RM1SepEx]

Tune, Build and Engineer to win are all great books!

Wheel width has been touched on a bit, must be sized properly for the tread to work well

As noted by several of us earlier tires are not a normal friction, easy to model situation

And also agreed real life doesn't exactly follow calculations... that's what makes life so interesting and fun!

A wrx pushes because it is an overpowered appliance, not a sports car, too many compromises in the design, think refridgerator, a BMW 335 would be a sports sedan

[Smythe]

Every car has its trade offs, even your 335. Performance vs cost, luxury vs performance, fuel economy vs performance, fuel economy vs cost... and on and on.

Not sure I would call a WRX an appliance, or overpowered, but I guess I'm also a little partial.
In an AWD car your asking the front wheels to turn and accelerate, there is only so much grip. Also not loading the front tires on turn-in is going to get you to push, more so in a vehicle that is light in the front end. Which was my point with the previous post.

[305mouse]

On my 92X changing the sway bars made a huge improvement over tire width. I plan on running a skinnier tire up front.

[skullandbones]

There has been some talk about the various racks that can be used. I know from discussions about the racks on the roadsters and coupes that the power units make it easier to run more caster and toe in to help the car steer straight and reduce bump steer. I don't know how that may or may not affect the over or under steering if any. I think there may be a tendency for the 818 to oversteer but I am only guessing at this point. Any thoughts on the front end steering? Thanks, WEK.

[Silvertop]

There has been some talk about the various racks that can be used. I know from discussions about the racks on the roadsters and coupes that the power units make it easier to run more caster and toe in to help the car steer straight and reduce bump steer. I don't know how that may or may not affect the over or under steering if any. I think there may be a tendency for the 818 to oversteer but I am only guessing at this point. Any thoughts on the front end steering? Thanks, WEK.

Given that the engine will be mounted in front of the rear wheels, and with the driver just behind the front wheels, I would expect this vehicle to be reasonably well-balanced weight-wise, more or less neutral steering with maybe only a slight tendency to oversteer.. But I'm really just guessing too.........

[el_jefe]

If it follows the rule of thumb of mid/rear cars, it will be neutral to the limit, and then let go into oversteer rather abruptly.

But the basic handling will be determined by geometry, suspension settings and bushing components. I've never driven an FFR car before, how much understeer do they dial in with their base settings?

[skullandbones]

el_jefe,

That's a very interesting question. And I have no idea. I think this is almost like the chicken and the egg question. That's why I mentioned somewhere else that I would love to be present during the prototype testing. There is a lot of racing experience based at FFR not only from in house but I'm sure from almost endless insider racer types all over the country. Don't you think the "test pilot" will be the main driver (pun) in that process assuming the car is somewhat balanced? I wonder if Dave is the "test pilot". Thanks, WEK.

[shinn497]

Late response I know.

http://www.youtube.com/watch?feature=player_embedded&v=AXhVv6_AeOU

Vid where Jim states that the 818 weight is WET sans driver. Skip to 5:30.

Edit: checked out the Roding roadster. The 1.4g quoted time is insane. I'm a little skeptical of that.

also remember that WRX's quouted BHP is 230hp but 265 can be easily achieved with an ecu tune. At that level the 818's power to weight just match the RR's.

[RedJoker]

I've never driven an FFR car before, how much understeer do they dial in with their base settings?

This is an interesting question as I don't know of any two FFR's built the same way. On race tires, my roadster is pretty neutral but I'm using the same width front and rear tires. For the street, I run narrower front tires to ensure understeer for safety reasons.

Of course, you'll find most loss of control in an FFR car is due to having so much power and so little talent. :rolleyes:

[BipDBo]

also remember that WRX's quouted BHP is 230hp but 265 can be easily achieved with an ecu tune. At that level the 818's power to weight just match the RR's.

You're right. The WRX had 230 hp up until 2007. After 2007, it had 265 hp, but that's not a valid 818 donor vehicle. My mistake. I'm sure though that many peole will push that enginewell above 300hp, and some may even figure out how to squeeze in the newer, more powerful engine.

[Nuul]

300 crank is what I'm shooting for. My thinking being that if I'm going to buy a high mileage donor car I'm taking the engine apart anyway - I might as well add some ponies to it while I'm in there.

[BipDBo]

300 crank would really make it cook. Assuming a 200# driver, to match the power weight ratio of a Corvette Z06, you'll need 297 hp. To match the Z06, you would need 362 hp. I don't know what kind of budget would be needed to hit 360 hp, but I'd bet 300 hp wouldn't be hard to acheive. Also, the weight distrubution should give it an edge over the Vette.

[Silvertop]

300 crank would really make it cook. Assuming a 200# driver, to match the power weight ratio of a Corvette Z06, you'll need 297 hp. To match the Z06, you would need 362 hp. I don't know what kind of budget would be needed to hit 360 hp, but I'd bet 300 hp wouldn't be hard to acheive. Also, the weight distrubution should give it an edge over the Vette.

I'm no expert, but according to Subie experts frequenting this site, 300 HP is easily achievable with bolt-ons (intake, exhaust, ECU tuning), and engine internals will handle up to 350 flywheel horsepower without modification.

[Nuul]

It's possible to get 400 WHP (http://forums.nasioc.com/forums/showthread.php?t=1393580) (no idea what that is at the crank) if you are willing to spend the money.

Taken from the link:
GT30R rotated mount turbo kit
Front mount intercooler
Header to go with whatever up pipe that setup uses, even better if they make a header specifically for their rotated kit.
Injectors
fuel pump
Intake (this will be part of the rotated kit most likely)
Custom tune obviously.

[Silvertop]

It's possible to get 400 WHP (http://forums.nasioc.com/forums/showthread.php?t=1393580) (no idea what that is at the crank) if you are willing to spend the money.

Taken from the link:
GT30R rotated mount turbo kit
Front mount intercooler
Header to go with whatever up pipe that setup uses, even better if they make a header specifically for their rotated kit.
Injectors
fuel pump
Intake (this will be part of the rotated kit most likely)
Custom tune obviously.

I'm sure that's true. But I'm not sure I would want to take the HP numbers much above 350 at the flywheel without adding some strength to the engine internals (crank, rods, etc). Just my humble opinion, unsubstantiated by personal experience..........

[Nuul]

Agreed. I would want all forged internals if I was running that kind of power. Add to that fact that you're going to have to spend a good amount on the transmission too and you're looking at some money. If you did it in phases it wouldn't be so bad but it's probably already stupid fast at 265 HP let alone 300...400 is probably pushing the limits of sanity in such a light car.

[Oppenheimer]

You're right. The WRX had 230 hp up until 2007. After 2007, it had 265 hp, but that's not a valid 818 donor vehicle. My mistake. I'm sure though that many peole will push that enginewell above 300hp, and some may even figure out how to squeeze in the newer, more powerful engine.

Wondering, are the 2007+ not suitable donor per FFR simply because its not suitable as single donor? (like its just the dash or suspension or something that doesn't work?) FFR is big with marketing the single donor thing. But if you used, say, a base impreza as your donor, any reason you couldn't then substitute 2007+ WRX powerplant?

Is there a reason 2007+ powertrain won't bolt in?

[Silvertop]

Agreed. I would want all forged internals if I was running that kind of power. Add to that fact that you're going to have to spend a good amount on the transmission too and you're looking at some money. If you did it in phases it wouldn't be so bad but it's probably already stupid fast at 265 HP let alone 300...400 is probably pushing the limits of sanity in such a light car.

Got to agree with that, too. Frankly, I'm leaning toward a standard Impreza NA version, perhaps tweaked to generate 200 HP or so. In an 1800lb vehicle, it would still be plenty fast, be a lot easier to drive by normal humans, would escape all the turbocharger heat soak issues, and be much less likely to shred other driveline components.

[BipDBo]

Wondering, are the 2007+ not suitable donor per FFR simply because its not suitable as single donor? (like its just the dash or suspension or something that doesn't work?) FFR is big with marketing the single donor thing. But if you used, say, a base impreza as your donor, any reason you couldn't then substitute 2007+ WRX powerplant?

Is there a reason 2007+ powertrain won't bolt in?

I really don't know. I kind of vaguely remember a comment from Dave very early on, that there was an issue in converting the transaxle from either the STI or the newer WRX models to drive 2 wheels. I remember not understanding the issue, and I could easily be way off.

I'd imagine that whatever the issue, is, that they will be working to rectify it for future versions of the 818. If they can get a VW diesel in there, I'm sure they can get any subaru boxer 4 to work.

The 818 will need to be flexible so that it can be adapted to future Subaru products as well. It's rumored that Subaru is developing a new WRX engine: direct injected 1.6 liter boxer 4 that produces 270 hp. I'm guessing that it will also be lighter.
http://www.autoblog.com/2011/07/15/subaru-to-split-wrx-from-rest-of-impreza-line-make-it-smaller/

[Oppenheimer]

Yes, its the same formula used by the Roadster, keep up with latest Mustang drivetrains. In this case, keep up with the latest Subie boxers.

[Nuul]

I really don't know. I kind of vaguely remember a comment from Dave very early on, that there was an issue in converting the transaxle from either the STI or the newer WRX models to drive 2 wheels. I remember not understanding the issue, and I could easily be way off.

You're probably on to something. The STI has a 6 speed so maybe it doesn't convert as well because of size or other mechanical limitation.

[armstrom]

If it follows the rule of thumb of mid/rear cars, it will be neutral to the limit, and then let go into oversteer rather abruptly.

But the basic handling will be determined by geometry, suspension settings and bushing components. I've never driven an FFR car before, how much understeer do they dial in with their base settings?
Sorry to reply to an older post, but I don't know that this behavior should be expected of the 818. Most mid-engine cars that have a reputation for snap over-steer have a different layout than the 818. A famous example is the 2nd gen MR2 (I own one). These cars are known to be a bit "twitchy" at the limit and lifting off at the limit can easily send you spinning through a corner. However, cars that exhibit this behavior are usually built with a transverse FWD drivetrain simply transplanted to the back of the car. This puts the bulk of the engine mass directly over the rear axle. This creates a longer moment-arm for for the mass of the engine as it exerts lateral forces against the rear tires. This type of mid-engine car is actually approaching the handling characteristics of a rear engine car where the moment arm of the engine mass actually exceeds the length to the tires ( LOTS of snap oversteer :) )

However, the 818 is more "mid-engined" than most non-exotic mid engine cars on the market. The engine mass sits well in front of the rear axle. This is more like the configuration of exotic mid engine cars and not as prone to out of control oversteer at the limit.

Now, as you said, the final result will still depend greatly on the alignment setup, suspension geometry and dynamic properties of things like springs, dampers and anti-roll bars.. But having the engine where it is in the 818 gives a better starting point or "baseline". A good setup can always improve from there just like a bad setup can ruin it :)
-Matt

[mobius]

so we are looking at 2000lbs with driver roughly, at 300hp crank we are 6.67 lbs/hp the new Z06 is 3200lbs and 505hp giving it a 6.34 lb/hp. So we would have to be at 315hp to be equal of course the z06 is a little heavier with driver. If I go this route I would want to be a little better than that... im thinkin 400whp so around 4.35 lbs/hp would be real fun.

the wrx tranny is a little weak in that range. unfortuantely from what i have seen the sti tranny will not bolt up. anyone else know more about sti parts fitting or not?

[VTX]

so we are looking at 2000lbs with driver roughly, at 300hp crank we are 6.67 lbs/hp the new Z06 is 3200lbs and 505hp giving it a 6.34 lb/hp. So we would have to be at 315hp to be equal of course the z06 is a little heavier with driver. If I go this route I would want to be a little better than that... im thinkin 400whp so around 4.35 lbs/hp would be real fun.

the wrx tranny is a little weak in that range. unfortuantely from what i have seen the sti tranny will not bolt up. anyone else know more about sti parts fitting or not?

I could be completely off base here, and someone correct me if I'm wrong, but the whole lb/HP argument seems like it doesn't give you the entire picture. It seems to me that it is probably more relevant for straight line performance, which doesn't seem to fit the purpose of the 818.

The fact that the 818 is so much lighter than a Z06 is going to give it a nice advantage all by itself. If I had to guess, I'd say you won't need as good a lb/HP ratio to equal the performance of a Z06 for the type of driving I see this car was really built for.

Not that there is anything wrong with shooting for 400HP, but I think people are going to be surprised by just how good this thing will do with much less than that.

[Oppenheimer]

Even being the 'cost effective' FFR, its still a dream car. And you can't stop people from dreaming big about their dream car. So naturally people start dreaming how they want to be faster than the guy who just wrote a big check.

I think most people will be flat out blown away by stock WRX power in this car, especially those that will be building a street car. But some won't be satisfied just having an awesomely fast, beyond fun car. They must have bragging rights in the form of lb/hp. And that is cool. It will bring notoriety to FFR and the 818, and performance numbers to show up in charts of the fastest cars there are.

I'm looking forward to seeing what sorts of numbers the over the top 818 builds can lay down. But I think the more reasonable builds will actually be more fun to drive on the street.

[mobius]

Even being the 'cost effective' FFR, its still a dream car. And you can't stop people from dreaming big about their dream car. So naturally people start dreaming how they want to be faster than the guy who just wrote a big check.

I think most people will be flat out blown away by stock WRX power in this car, especially those that will be building a street car. But some won't be satisfied just having an awesomely fast, beyond fun car. They must have bragging rights in the form of lb/hp. And that is cool. It will bring notoriety to FFR and the 818, and performance numbers to show up in charts of the fastest cars there are.

I'm looking forward to seeing what sorts of numbers the over the top 818 builds can lay down. But I think the more reasonable builds will actually be more fun to drive on the street.

very true. the videos of the ariel atom at 300 hp are pretty amazing, so i am sure it will be a ton of fun even at stock power even with the extra 500lbs.

[metalmaker12]

250whp @ 818kg vs My stock Sti 250whp@3200lbs
0-60 : 3.6-3.8 sec 4.5-4.8
0-100: 8-8.5 sec 12-12.5
1/4 mile: 11-11.5sec @ 130ish 13-13.5
top speed: 160mph 153

I think my times are very reachable, and 250-300 whp is all you need in the 818, any more and you will spin out coming out of corners, the car is light, you would need formula one like down force to get 500-600whp down with control

[Flamshackle]

I think my times are very reachable, and 250-300 whp is all you need in the 818, any more and you will spin out coming out of corners, the car is light, you would need formula one like down force to get 500-600whp down with control

This^

The 818 with a big turbo like mine will run will be a beast to manage coming out of a corner. going from somewhere around 150HP to 400HP within a 1000 RPM range will be tricky. BUT FUN!!! :D

For daily driving on the street the more conservative builds will be easiest and very rewarding to drive.

[shinn497]

I'm starting to agree with some of the NA/stock builds. I just got a 2100 pound 1.6 liter miata. And it is a hoot to drive. I think it has been modified with CARB legal headers and maybe an exhaust, but I really don't feel the need to turbo it or all that jazz (rather save the money for the 818).

Sub 4 seconds on a car of comparable size would be quite insane. I think a stock 818 could keep up with the V8 miatas. With mods we are talking super car levels.

I would still want to eventually put an EJ207 for the quick spooling turbo and 8000rpm redline as a later mod. THAT would be a fun car.

[Niburu]

I'm starting to agree with some of the NA/stock builds. I just got a 2100 pound 1.6 liter miata. And it is a hoot to drive. I think it has been modified with CARB legal headers and maybe an exhaust, but I really don't feel the need to turbo it or all that jazz (rather save the money for the 818).

Shinn are you on ClubRoadster or Miata.net?
<same screen name at both locations
I've got a 1.6 Miata as well, love the little bugger

[marcuss]

Agreed, This kit is being developed primarily as a street legal track day car, Although some of us may drive it on the street daily:-) But for what it`s being developed for 250-300hp will be more than enough for this car!!! Just look at other light weight cars numbers and their power levels!! What`s a sti weigh? 3200lbs?? this thing is gonna be around 1800lbs!?!?

[Xusia]

This kit is being developed primarily as a street legal track day car, Although some of us may drive it on the street daily.

There's no doubt Dave intends the 818 to be a very good track performer. I just don't think that's the primary focus. The customer base just isn't big enough for his stated goals, and the design criteria he has outlined are more in line with a car that is intended as a daily driver that would also perform very well on the occasional track day.

[Movieman]

There's no doubt Dave intends the 818 to be a very good track performer. I just don't think that's the primary focus. The customer base just isn't big enough for his stated goals, and the design criteria he has outlined are more in line with a car that is intended as a daily driver that would also perform very well on the occasional track day.

Agreed, at least that's the way I interpreted it.
BUT..Bottom line this will be seen differently depending on what the person is most interested in.
I can see lots of people with a stock motor smiling at the "brisk" performance and at the other end some crazed beastly concoction with 400+HP ripping up the asphalt with every breath..
Just thinking back to 1969 and the Camaro: You could buy a 250ci/150hp 6 banger or order a 396/375hp V8
Both Camaro's, both totally different uses.
The 818 will be the same and I think we'll enjoy them all.

[marcuss]

What you say is very plausible I guess this is why they are talking about making several variations of the same running chassis, To make a car that will suit different peoples uses and desires!! I'm just hoping the first one to market will be basically a street legal track car with a removable top for daily drive ability:-)
There's no doubt Dave intends the 818 to be a very good track performer. I just don't think that's the primary focus. The customer base just isn't big enough for his stated goals, and the design criteria he has outlined are more in line with a car that is intended as a daily driver that would also perform very well on the occasional track day.

[metalmaker12]

Dave in all due respect I have not found a donor impreza or wrx lower than 2500 unless the motor was blown or had major front end or suspension damage. If you or anyone can find one low cost in sorta one piece, send the link my way. I am buying a 818 kit as soon as it comes out. I have owned a wrx and a sti, Tehy are great cars, too bad I sold them. Great kit idea I love it!!!!!

Chris Marciano from Rhode Island
401 523-9249
surfpoint2@yahoo.com

[Xusia]

FFR is planning on a track version, and among other things, they've indicated it will include upgraded suspension and brakes. I would assume those same upgrades would be options on the other versions (such as the first-to-be-released "affordable roadster"). Therefore, you could conceivably upgrade your kit and "make it so." :D

[Evan78]

Dave in all due respect I have not found a donor impreza or wrx lower than 2500 unless the motor was blown or had major front end or suspension damage. If you or anyone can find one low cost in sorta one piece, send the link my way. I am buying a 818 kit as soon as it comes out. I have owned a wrx and a sti, Tehy are great cars, too bad I sold them. Great kit idea I love it!!!!!
Chris, I think you must have misinterpreted something. I don't think anyone has claimed that you can buy a running donor for much less than $5k. That's the approximate number people have thrown around a bit. FFR has said they are targeting a kit price of $10k with it being possible to have a completed car for an ultimate cost of $15k if you do a bare minimum build and are wise about your parts purchases (buying cheap and/or selling off unused donor parts). i.e. spend $10k on 818 kit, buy donor for $7k, sell off everything you don't use for a few thousand. I sold a 2002 wrx sedan rolling chassis without engine, trans, diff, etc for $2600.

[Nuul]

I sold a 2002 wrx sedan rolling chassis without engine, trans, diff, etc for $2600.

^ This exactly. I'm hoping to recoup ~$2K of the donor by selling off the odds and ends I don't need. If you do a total part out on the NASIOC forums I think it's doable. The question is if you want to deal with the hassle of taking everything apart and shipping it to 30 people.

[bromikl]

I've seen complete running WRX's for under 5K. Here's one:

http://milwaukee.craigslist.org/cto/2938194711.html

I think I'd prefer a 2.5 Impreza RS as a donor. Cheaper, simpler and more predictable power = more fun!

[Evan78]

^ This exactly. I'm hoping to recoup ~$2K of the donor by selling off the odds and ends I don't need. If you do a total part out on the NASIOC forums I think it's doable. The question is if you want to deal with the hassle of taking everything apart and shipping it to 30 people.My figure is actually not as applicable as I first thought, I sold it with many of the parts the 818 would need - suspension, steering, and pedals. I guess for those that buy a full car for an 818 build should just sell off all the body panels and strip it to the bare chassis and sell the chassis to a recycler.

[StatGSR]

Dave in all due respect I have not found a donor impreza or wrx lower than 2500 unless the motor was blown or had major front end or suspension damage. If you or anyone can find one low cost in sorta one piece, send the link my way.


who said anything about $2500 for a wrx (5K has been the only target price i have seen from FFR and as mentioned above, that would after partout of the rest of the shell), in any case if you go for earlier gen imprezas or legacys, you could easily buy one in running condition for $2500 or less...

[Ophitoxaemia]

Performance numbers for a mild build with auto trans?

[NonProfit]

Performance numbers for a mild build with auto trans?
Ophitoxaemia here are some rough estimates (http://thefactoryfiveforum.com/showthread.php?5789-Impreza-build-STI-engine-worth-it&p=56730#post56730).

[metalmaker12]

Performance numbers for a mild build with auto trans?

What!!!! No auto trannies please, that is like not cool, stop that thought, unless you have a disability and you can't shift, it is a big no no in a car like this

[metalmaker12]

I sold my doors complete for 225 a piece, all plastics to interior for another 200 and hood, fenders and deckled for 300,

I have all the parts i need from a doner except the engine and it cost 2k, but i got 1400 back selling parts in one month. I am getting a 04-06 sti engine for 3-4k and that will complete my needed parts list. So 1600-2600, plus rebuild parts, 1000, pluss 10k. Under 15k to get on road, gives me a lot off upgrade room to my total money to use of 20k