The curbweight thread

[BrandonDrums]

818R: Curb weight 1906 lbs. This was with all fluids, painted body (stock kit will not need paint), street fuel tank with 10 gallons fuel, and aero parts, Subaru harness (un-modified-no wire diet), fire suppression, and GTM seats. When we added the race fuel cell and changed to a Kirkey roadracing seat, we got 1950 lbs (fuel amount was estimated at 1/2 tank). Road & Track scaled the car but FILLED the 18 gallon fuel cell and the car came in at 2,011 lbs full.

818S: Curb weight 1847 lbs. This was with windshield, full street set-up, all fluids, stock fuel tank with unknown fuel level (estimated at 1/2 full), and utilizing WRX rather than impreza running gear (Impreza non-turbo would net maybe 50-90 lbs less!). This was with GTM seats rather than stock subie seats (which would be heavier by a bit).

There's a little bit of discussion over in the DS '818 update coming today' thread but to really flesh things out on-topic I think this deserves it's own thread.

I'll do my best to update Post One with the list of donor and kit part weights along with any notable links to other threads and weight savings mod plans as well. There's some great links in Post 2 by Longislandwrx as well that I recommend.

5/7/2013 update:

Subaru Front 4-Pot Brakes (Calipers, Pads, and Rotors) (294mm): 52.5lbs
Wilwood Front 4-Pot Brakes (Calipers, Pads, and Rotors) (304mm): 31lbs
Brembo STI 4-Pot Brakes (Calipers, Pads, and Rotors) (326mm): 66.1lbs
2002-05 WRX Front Brakes (Calipers, Pads, and Rotors) (294mm): 62lbs

Weights for rear brakes have been more difficult to find reliable (repeated measurement by different people) weights on, so I didn't list them.

2002-03 WRX Seats (Pair): 110lbs
2004-05 WRX Seats (Pair): 92lbs
2006 WRX TR Seats (Pair): 87lbs
Corbeau FX1 Pro Seats w/Brackets and 4pt Harness (Pair): 68lbs

2006 WRX 17x7" Wheels (Set of 4): 84lbs
2002 WRX 16x6.5" Wheels (Set of 4): 68lbs
Enkei RP-F1 17x7.5 Front 17x8 Rear: 62.7lbs


Stock Exhaust Upgrade
Manifold=19.5lbs HKS headers=15.5lbs
Uppipe/cat=6.5 PSP uppipe=2.5
Downpipe=23.0 MRT downpipe w/cat=14.5
mid pipe= 11.0 MRT mid pipe=10.5
Muffler=20.0 MRT muffler=26.0

Total=80lbs Total=69lbs

Great thread on Budget Lightweight Wheels on thefactoryfiveforum
http://thefactoryfiveforum.com/showthread.php?9945-Budget-Lightweight-Wheels-Thread

Because Sticky!

[longislandwrx]

a lot of weights are listed here

http://www.oakos.com/wrx/weights.htm

There were also these two weight reduction threads:

http://thefactoryfiveforum.com/showthread.php?7277-Weight-savings

http://thefactoryfiveforum.com/showthread.php?8023-Less-than-an-818



I'm going off the parts on the R, assuming they didn't do these already:

braille/odessey battery -15lbs
lightweight pulley -4lbs
street spec lightweight flywheel-11lbs
header/uppipe combo -20lbs
all aluminum lateral links -2lbs
composite TGV -4lbs
remove GBOD -4lbs
wiring reduction -10lbs
porting and emissions removal -2lbs
lightweight brakes -20lbs
no paint -5lbs
oem radiator -7lbs

That's over 100lbs right there, take off another 50 for half a tank of gas. Gives me about 1860lbs... I think there's a lot more to be found too.

[BrandonDrums]

I think this is a good case for STICKY THREADS!!

You made the thread I wanted to find...but I couldn't find it. I mean, we could do a single thread that we simply link sticky threads and what they are about....

Thanks for the feedback.

Now that we have more of the final details about the chassis itself, anyone have any insight to things that might be done on the body/chassis to save weight?

[Darkpiggy's dad]

Never forget the weight of the driver. I could lose 50 lbs :) . Seriously, removing unsprung weight and anything that will lower the center of gravity is my quest. Lightweight steering wheel, seats. Is a poly windshield legal on the street? Aluminum windshield frame?

[bnr32jason]

Brandon it would be cool if you could keep up on this thread and organize it into different sections. We can add our weights to the thread and then you update the original post to include those things.

While I don't have many parts to weigh myself, I've gathered together some fairly reliable weights for different parts that people may or may not use.

Subaru Front 4-Pot Brakes (Calipers, Pads, and Rotors) (294mm): 52.5lbs
Wilwood Front 4-Pot Brakes (Calipers, Pads, and Rotors) (304mm): 31lbs
Brembo STI 4-Pot Brakes (Calipers, Pads, and Rotors) (326mm): 66.1lbs
2002-05 WRX Front Brakes (Calipers, Pads, and Rotors) (294mm): 62lbs

Weights for rear brakes have been more difficult to find reliable (repeated measurement by different people) weights on, so I didn't list them.

2002-03 WRX Seats (Pair): 110lbs
2004-05 WRX Seats (Pair): 92lbs
2006 WRX TR Seats (Pair): 87lbs
Corbeau FX1 Pro Seats w/Brackets and 4pt Harness (Pair): 68lbs



2006 WRX 17x7" Wheels (Set of 4): 84lbs
2002 WRX 16x6.5" Wheels (Set of 4): 68lbs
Enkei RP-F1 17x7.5 Front 17x8 Rear: 62.7lbs

[longislandwrx]

Yeah the search is tough when you can't search for short words.

As far as removing weight from the frame, I imagine FFR has done their best to keep the weight down. I am going to make the cross bar removable, but the clevis mount will most likely weigh the same as the bar itself.

Removing some of the sheetmetal from the fender liners etc might drop some lbs but at the expense of not protecting the body.

Other ideas:

The intake manifold can be switched with the composite version although you will need a new turbo/intercooler/bov or custom piping. should save a little weight though. Or reduce the weight of your aluminum one by cutting all the unused tabs off it.

Extensive use of titanium and aluminum fasteners, aluminum is cheap but not very strong but it is perfect for brackets/mounts/accessories. Titanium works awesome, but costs a small fortune. You could easily spend several thousand dollars to save a few lbs.

A racing weight flywheel will save you another 4 pounds, but I'd like a little mass for the street.

Running narrower tires like a 225 all around on smaller forged 7" or so wheels will save quite a bit, but traction will suffer.

a racing alternator weighs about 6 lbs ... not sure what the oem one weighs, or drop the alternator all together for quick autocross sessions.

[PhyrraM]

Subaru Front 4-Pot Brakes (Calipers, Pads, and Rotors) (294mm): 52.5lbs

2002-05 WRX Front Brakes (Calipers, Pads, and Rotors) (294mm): 62lbs



Thin one is hard to swallow. They use the same rotor and the pads are negligible. I've had both in hand and the cast iron 4-pots seem heavier than the WRX 2 pots.


Very interested in this thread, as I still can't see how the 818 even gets to 1800 pounds - just by adding component weights. I'd love to see the weights of some of the FFR fabricated parts to help with my frame of reference.

[bnr32jason]

I thought it was a bit odd as well, but I've seen three different weights for those and they were all within a pound of eachother, so I'm assuming it's accurate.

[BipDBo]

As far as removing weight from the frame, I imagine FFR has done their best to keep the weight down.

May I propose an option for the chassis structure to be built from an alternate material?

I'm not sure exactly what kind of steel FFR is using in the 818 chassis, but the GTM is said to use "high strength 1020 and mild carbon steel tubing and plate steel" 1020 all around, is a pretty good selection for the application. There may be some better options, with added cost, of course.

Chromoly (4130) steel, for example, has the same density, but is anywhere from 10% to 50% stronger, depending on who's numbers you are looking at, so theoretically, 9% to 33% less of it could be used. The tubing, though is more expensive, but more importantly, is more difficult to weld. Labor cost would be higher.

Aluminum is another possibility. The density of Al is about 35% that of steel. A cheap, readily available Al alloy such as 6063-T5, though has about 52% of the tensile strength of 1020 steel. To match the tensile strength of any particular 1020 steel tube, the wall thickness would need to be 90% thicker, and the tube would be 33% lighter. Moving to a more expensive Al alloy such as aircraft grade 7075, the tensile strength nearly matches 1020 (95%), yet the density is still 35%. A chassis built with Al 7075 would certainly be more expensive, but it could theoretically be 64% lighter.

The cheapest bikes use mild steel, but most are now aluminum, mostly likely 6030. Mid range bikes use chromoly steel. The higher end aluminum bikes use 7075. The most expensive, lightest bikes, of course are made of carbon fiber.

There are a lot of aluminum sheet metal panels in the 818, so having an aluminum chassis and using aluminum fasteners might reduce corrosion by keeping the metals similar.

Tensile strength, however is not the only thing to consider. Stronger alloys tend to have lower % elongation. IE they are more brittle. Other figures to look at are the modulus of toughness and modulus of resilience. A material with a high % elongation will stretch further before failing. Stretch to failure is much more simple and predictable than a chassis crumpling under compression in a wreck, but in general, this is an indicator of how much energy it can absorb in a crash.

http://www.onlinemetals.com/steelguide.cfm
http://www.onlinemetals.com/alloycat.cfm?alloy=4130
http://www.onlinemetals.com/aluminumguide.cfm
http://www.engineersedge.com/materials/carbon-steel-properties.htm
http://en.wikipedia.org/wiki/6061_aluminium_alloy

[RM1SepEx]

Wow... remove weight from the frame.... alternate materials...

just remember $9990 for that you don't go alternate or high strength. Goal is to reuse as much as possible from the donor... I'm sure that 1800 is doable if it means that much to you. If you want the absolutely lightest weight that cost $$$$$

[Mechie3]

Have you ever priced out the cost of 4130 or 7075 to standard carbon steel or 6061 al? You'd be paying $30k for the kit alone.

[BipDBo]

Have you ever priced out the cost of 4130 or 7075 to standard carbon steel or 6061 al? You'd be paying $30k for the kit alone.

I'm just throwing out theoretical ideas. I really don't have any idea how much of a price difference they would be. I do know that 7075 would likely astronomically expensive. 6061, however is the same alloy in coke cans. Different strength grades depend on the tempering process. 6061 would not carry nearly the premium that 7075 would.

I'm just proposing this as a factory upgrade, not for the base kit. The best thing about the 818 is that it's affordable. Ultra high end, ultra expensive exotics are a dime a dozen these days. Affordable HOF performance is rare. Depending upon how much weight that saves, however, $30,000 might get some takers. I don't have that kind of money to spend, but many people do.

FFR is set up for and experienced with working with 1020 and mild carbon steel, so switching to another material for a few custom orders may not be practical. This may be something that FFR could more economically outsource to another shop that may routinely work with that material.

Another idea for a factory option would be carbon fiber body panels in lieu of fiberglass. This may be more practical. Laying carbon is not incredibly different from laying glass. You just use less of it.

[Mechie3]

I would think a lot of weight benefits would come from making billet aluminum parts to replace heavy cast iron parts (like hubs).

[Evan78]

Anyone have weights for Stoptech brake kits?

[BrandonDrums]

I think there's a case for "hybridizing" the chassis with high strength aluminum stock. The primary stressed components like the dual tubes, roll bars and suspension mounts should remain steel since you need them to be solid welds.

However, there are a lot of cross-supports for preventing flex in some of the framed sections of the chassis that could be cut out and replaced with aluminum bars via bolts. However, that means someone is going to have to chop up their brand new 818 chassis, bolt in some bars and test things out to see if it breaks.

That being said, it would be extremely easy to cut out the frame for the dash and replace it with lightweight aluminum stock. The other thing that wouldn't be an issue is cross drilling some of the less structural bars like swiss cheese. When done correctly it saves a lot of weight without sacrificing the overall compression strength of a hollow bar which should preserve the strength of the chassis.

http://i996.photobucket.com/albums/af89/BrandondrumsWRX/2013-05-07_1710_zps99aa4e2f.png

[Twinspool]

When someone offers you a 1900lb roadster kit for $10k, the only answer is giggling like a moron and saying yes.

Feel free to rebuild the frame in titanium or billet 7075 and post it up when you're done. Love to see it.

[bnr32jason]

I'm not as crazy as some of these guys, I'm not going to modify the chassis whatsoever. I'm going to lower weight through the things listed in this thread, stuff like wheels, suspension components, brakes, seats, etc. I wish the guys who want to take it even further the best of luck, but that's way beyond my scope and what most people are going to want to do. I'm having a hard enough time imagining what 350hp is going to feel like pushing around 1800lbs on the street, I've only felt power:weight like that on the track with full slicks.

[shinn497]

anyone know what the weights for gtm seats are

[longislandwrx]

I would think a lot of weight benefits would come from making billet aluminum parts to replace heavy cast iron parts (like hubs).

yeah until you look at the prices of MSI's stuff :eek:

17562

so damn sexy.



anyone know what the weights for gtm seats are




This was with GTM seats rather than stock subie seats (which would be heavier by a bit).



From this I would estimate about 70 lbs for the pair.

[Dave Smith]

I love the concept that the engineers have adopted over time on the race cars. Essentially weight is the enemy. Lotus and countless racers understood this concept.. Still, you have to keep in mind that weight is one of many design goals. Price was integral as was cost to complete. Just those two are in sometimes huge conflict. Add in easy to build (this is targeted to export customers around the world and it makes it hard to do tech in another time zone and accross language barriers). Performance goals involved ALOT more than power, which was also affected by running gear selection. I guess what I'm saying is that I am stoked that the design team nailed the weight goals and so many others. This is so much like playing chess in that there are many moves that may win, but they all affect each other. We can definitely go lower with alternate materials, carbon, aluminum or more exotic chassis materials, etc... I think that everyone here is BURSTING knowing how friggin fast this car is. We're going to run it with Grassroots Motorsports in the Ultimate Track Challenge. my prediction is that the car will be in the low two minute range at VIR with the next fastest car and the next slowest car around it costing 5x as much.

Lets go back two years ago to the original goals and targets:

Single Donor Subaru WRX Running Gear
Factory Five Space Frame Chassis, 95″ Wheel Base
Mid-Engine, Rear Wheel Drive Configuration
Target weight – 1,800 lbs./818 kg.
Two Seater Sports Car Design
No Paint, Thermoformed Body Panels
Target Kit Price: $9,900
Target Vehicle Completion Cost Under $15,000
Design Partners: SolidWorks Software, Hewlett-Packard, Grassroots Motorsports Magazine, KONI Shocks, Wilwood Brakes, Toyo Tires, TheFactoryFiveForum.com
Production Target Dates 2012-2013

We did NOT list performance and safety goals as those were implicit in the name Factory Five Racing, nor did we crow about "easy-to-build" as that was more for us on the support side than anyone else and FFR's are generally the best engineered kits out there and we were taking this to another level. Still, these things were strong drivers in the development process. The paint-free panels are accomplished, but with initial gel coat rather than the thermoform process.

The project has been guided by a plan, well executed, and we've done what we set out to do. Yesterday the welding jig produced its FIRST production frame (20 days ahead of schedule) and the tools have been moved to production from R&D.

One last thought: I have been a fan of motorcycles forever and the weight is sooo important. Also the weight is an area that inexplicably manufacturers could never get right. They would claim a "dry weight" which is unimportant as no-one rides a bike without fluids and even the dry weights were like, "Is the gravity different in Japan?!" sheesh. Nowadays weights are more accurate but there are still eccentricities (like Road and Track and Car & Driver use full gas tanks which HUGELY penalize cars with bigger fuel cells whereas 10 gallons would be standard that, while hard to always keep striaght, would make things fair). For us the fact that everyone will build the cars a bit differently (ie. we painted our car and most won't.. thats maybe 25 lbs) makes it more difficult. BOTTOM LINE is that I am pleased that the target was accomplished and without breaking the bank, guys can go even lower, although I truly believ, after driving the car, few will.

[JAubin]

Cutting out sections of the frame and bolting in aluminum would be reducing the strength, rigidity, and safety of the frame to a point that I'm not sure anyone would deem acceptable. If going for a "lightweight money is no object build" welding up an entirely new frame would make a lot more sense. Though, I'm sure you can weight way more cost effectively via weight reducing components than the frame itself.

[Oppenheimer]

To paraphrase a common engineering idiom, Cheap, Light, Good, pick any two.

FFR somehow managed to do all 3. You want it even lighter, then one of the other two is going to take a big hit. Fine so long as you know this going in.

[Mechie3]

20 days early! Does that mean I can get my kit July 1 and not July 20!!???!?!

(wishful thinking..I know).


Another quote I've heard: Speed costs money. How fast do you want to spend?

[longislandwrx]

How do you make a small fortune in racing? start with a large fortune.

Frames! that's great news.

[Xusia]

Personally, I'm not inclined to mess with the frame, though I would love to see someone spend the money to have FFR make one in all aluminum! Things that bolt to the frame are potentially fair game for lighter weight materials. For me it will depend on cost and relative gain. I plan to add things like a heater, A/C, stereo, sound dampening, etc., so obviously having a low vehicle weight is not my top priority. :)

[BrandonDrums]

....I was really just making conversation guys. I like most other folks won't be touching the frame.

However, there are guys out there that are mod freaks and will try anything. There are numerous examples of chevy powered '65 roadsters, electric '33 coupes, modified '65 roadster chassis to make other types of cars etc.

Not only do FFR make great packaged products but their kits also give a great platform to make things beyond the scope of the original product.

Another point: There's a small kit-car company that made ariel atom-like kits from scratch based on Subaru donor components. They are going out of business though according to my pal. However, there are some guys who talk about modifying the 818 chassis to make it an exo car and lightening the chassis. One of my best friends is one of those guys, he planned on building a "TR-42" but he said they aren't going to be around much longer. I can't find details though.
http://forums.nasioc.com/forums/showthread.php?t=2093090

Anyway, I wouldn't really care if the 818 ended up being 2200 lbs myself, I would mod it much to make it lighter. I know how fast my wrx is and shedding even just 1000 lbs off would be insane. However, there are plenty of folks out there that I think might end up modding the chassis some for weight savings.

[Mechie3]

I was trying to find out how to get a TR42 a while ago, but couldn't find anything beyond that nasioc thread.

[RM1SepEx]

Personally, I'm not inclined to mess with the frame, though I would love to see someone spend the money to have FFR make one in all aluminum! Things that bolt to the frame are potentially fair game for lighter weight materials. For me it will depend on cost and relative gain. I plan to add things like a heater, A/C, stereo, sound dampening, etc., so obviously having a low vehicle weight is not my top priority. :)

Just remember to make a lighter aluminum frame it is a TOTAL redesign... most likely large box type spars down the sides, castings etc... We are talking way too much work to consider.

Remember AL is 1/3 the weight by volume but also has 1/3 the yield strength. Also steel deforms when stresses are too high. Aluminum just fails! Check out AL bike frames vs their steel counterparts...

steel tubing is cheap and strong, easy to work with. Al is none of those...

[Evan78]

I was trying to find out how to get a TR42 a while ago, but couldn't find anything beyond that nasioc thread.Not that it'll help get you a car, but there's a dedicated subforum on Exocars (http://www.exocars.net/forumdisplay.php?f=57) and SpeedInc.us (http://www.speedinc.us/) is the official site.

It appears he's already revised his website to remove TR42 references. Old versions are available on archive.org (http://web.archive.org/web/20121025101526/http://www.speedinc.us/).

I also dug up his forum (http://forums.velocityofky.com/).

[BipDBo]

My proposal for alternate materials of the chassis should in no way diminish the awesomeness of the 818 as it stands today. A car that offers that kind of performance for less than $20,000 is truly amazing. I was merely brainstorming an idea for the future, once the 818 has taken hold. When the Ariel atom came out, it offered performance that rivaled uber expensive exotics for a relatively very low $50K. In a few years, though, they offered, in limited production, the Atom V8 which was lighter, more powerful and much more expensive. Most customers, including myself will be ecstatic to build the 818 as it is with stock WRX power. There are already people, though dreaming up shoehorning in a 500hp H6 into this car. For such people who are a bit wealthier and clinically insane, I wouldn't mind seeing (from a safe distance) one day in the future, a limited edition 818 with an aluminum chassis and carbon fiber body.

[metalmaker12]

Dave, what color choices will we have in gel coat

[shinn497]

red white and blue

[Xusia]

...I wouldn't mind seeing (from a safe distance) one day in the future, a limited edition 818 with an aluminum chassis and carbon fiber body.

THAT's essentially what I was saying. :) Not in my budget, but I'd sure love to see someone do it!

[metalmaker12]

I have only seen red confirmed, but red white and blue would be a nice tribute to a great American company!!!! Do it

[Evan78]

red white and blueAre you referring to this statement by Dave on 4/23/13?


I think we'll launch in white or red or blue gel-coat with conventional hand-laid panels with no mold parting lines as the parts are all small panels that can release from high quality molds.I haven't noticed any clarification on if he meant customers will have all 3 options, or if there will be 1 color that is yet to be determined.

[metalmaker12]

I was told one color at moochfeast, red

[Evan78]

I was told one color at moochfeast, redThat was in February, right? The quote I posted is from April, so it sounds like they could end up with white or blue instead.

[AZPete]

I'm putting in my request now: RED
FFR, please note I love the red color of the prototype so this will be easiest for you, hence I'm a nice guy so move my ship date up the list to sooner than August 10th.
Pete

[metalmaker12]

I think I will know soon

[BrandonDrums]

A complete redesign would be overkill, just make your own car then. Just like the early design discussions, it's a discussion and there are plenty of things to chat about.

How about which car color is lightest?

[NorthStarUnlimited]

The upgrade to chromoly might net a 50# savings, but you'd be constantly dealing with cracks due to the more brittle nature of chromoly. The strength of chromoly is great for the track, but doesn't fare well on the street if you build with thinner tubing to save weight.

[BipDBo]

Does anyone know if there will be a weight difference between the current fiberglass body panels and the (hopefully) future thermo-molded panels?

[Matty_STi]

http://www.iwsti.com/forums/gd-members-journals/65805-anorexicsti-05-sti-lightweight-w-full-interior-2660lbs-62-lbs-2598-a.html

for ideas on where to save weight on a 05 wrx/sti. (he wanted to do 600lbs of weight reduction!!!!!!!!!!!!!)

-Matt

[shinn497]

Does anyone know if there will be a weight difference between the current fiberglass body panels and the (hopefully) future thermo-molded panels?

Been wondering this too. Moresoe, what would be the advantage of theromolded panels?

[Mechie3]

If it works, thermo formed panels would be faster to make, cheaper, and colored throughout so you could cut it and not have a white glass layer suddenly exposed needing paint.

[shinn497]

Do you know if they could make more complicated shapes? I remember hearing that part of the reason the current design is what it is (especially compared to some of the contest winners), was due to manufacturing costs. Indeed, I'm noticing that the curves and lines on it aren't very deep.

[07FIREBLADE]

Also therniformed will be lighter than fiberglass with other beneficial properties. More complicated shapes could be formed.

[Mechie3]

Cost has more to do with increased mold complexity (slides, pulls, etc for undercuts) not necessarily the material.

[longislandwrx]

http://www.iwsti.com/forums/gd-members-journals/65805-anorexicsti-05-sti-lightweight-w-full-interior-2660lbs-62-lbs-2598-a.html

for ideas on where to save weight on a 05 wrx/sti. (he wanted to do 600lbs of weight reduction!!!!!!!!!!!!!)

-Matt


While there are a lot of good examples in this thread, I wouldn't follow this guys example... his car is literally held together with Velcro, double sided tape, and bubblegum.

A lot of this stuff is far from safe.

[Oppenheimer]

Thermo formed panels = Sportbike body panels

Typically these are a solid color, with vinyl wrap added to create the graphics. While the graphics we use (if any) will likely be less complex (stripes, etc), the same process could be used (use colored vinyl wrap to add your graphics). This would be in the spirit of the low cost/low effort paintless body for the 818. They weigh almost nothing.

[Matty_STi]

Indeed, but doing some simple changes to fastners and using legit solutions for holding things together you can get similar results. The purpose of the link is less about following an example and more so about ideas on where the weight is and what can be done to remove it. Inspiration. Also, in some cases velcro and double sided tape are more than adequate. Bubble gum not so much ;)

-Matt


While there are a lot of good examples in this thread, I wouldn't follow this guys example... his car is literally held together with Velcro, double sided tape, and bubblegum.

A lot of this stuff is far from safe.

[longislandwrx]

Agreed, what can be done and what should be done are drastically different. I like a lot of his ideas but removing ABS brackets? :rolleyes:

[IMPREZvWRX]

Thin one is hard to swallow. They use the same rotor and the pads are negligible. I've had both in hand and the cast iron 4-pots seem heavier than the WRX 2 pots.


Very interested in this thread, as I still can't see how the 818 even gets to 1800 pounds - just by adding component weights. I'd love to see the weights of some of the FFR fabricated parts to help with my frame of reference.My only guess is that they're looking at the USDM 2006 WRX aluminum 4-pots.

[metalmaker12]

The 2006 front 4 pots are cast iron and the 2 pot rears are aluminum. The fronts are heavy, but perform well, and the rears are lite and work well. Both are reliable and easy to work on. I too am wondering how it gets to 1,800

17843 Front Blasted

17844 Rear Blasted

17845 All after a little powder

17846 Finished look, well without my hand

[RM1SepEx]

what do you use for the black paint on the center hub of the rotor? Mine are raw metal, I like that painted look but rotors get very hot.

[Silvertop]

Duplicolor (and other reliable paint makers) offer paint in aerosol cans (and brushable versions also) in a variety of colors including black specifically for brake calipers. I should think that these paints would stand up to a hot rotor hub equally well.

[RM1SepEx]

thanks, my new parts are getting a light surface rust that needs to be cleaned up and painted, I'll try some black caliper paint

[apexanimal]

i recall at one time that the two pot sliding front calipers actually had more piston area, more pressure feel, or something along those lines... essentially that the 4 pots were nice but that the standard 2pot sliders were quite capable and actually more desirable in some applications...

does anyone remember this at all?

[Dave Smith]

Pete! We'll launch in white but I'll keep options open for the second and third sets of production molds. As far as weight (the original topic of this thread) I was talking to the crew today about the 818S at Open House and we thought it would be cool to have the 818S drive into the event and up onto scales to show the "curb weight" We'll see. The boys are hard at work on the car right now.

[PhyrraM]

i recall at one time that the two pot sliding front calipers actually had more piston area, more pressure feel, or something along those lines... essentially that the 4 pots were nice but that the standard 2pot sliders were quite capable and actually more desirable in some applications...

does anyone remember this at all?

The stock WRX 2 pot calipers do produce more clamping force (on the same rotor, so more overall torque). The 4 pots are generally considered to have better 'feel', mostly because of the small change in pedal travel and possibly a more rigid caliper. The lower force in the front helps balance the F/R braking (for the better) in a stock WRX. I'm not sure if that will need to be the same in an 818.

For the 1800 pounds, and IMHO, even the stock WRX 2 pots are more than enough brakes. If a good pad selection is available, I plan to look into the single piston options on lighter Subarus. The 'small' 2-pots from the 2.5RS and the late '90s Outbacks might be a better/lighter option. Of course, for looks, most still prefer the 4-pots. FFR is also going to have a kit available from one of it's 3rd party partners, that is likely to be $$, but popular also.

[carbon fiber]

being realistic, it'll be best to remove unsprung weight, wheels/suspension/brakes. and then just add a little hp to get to the lbs. per hp target you want. light is good to a point, but then you start to give up traction, and 1800/1900lbs. is pretty light!

[Silvertop]

A complete redesign would be overkill, just make your own car then. Just like the early design discussions, it's a discussion and there are plenty of things to chat about.

How about which car color is lightest?

White reflects light. Darker colors such as Red and Blue absorb light. Given the added weight of the light, the white car has to be lighter..............:rolleyes:

[Mechie3]

The boys are hard at work on the car right now.

That's funny...I can't seem to find the link for the live webcam feed of the build. I'm sure it's there somewhere ;)

[metalmaker12]

That would be killer Dave, can't wait to just be there and be part of it all;)

[metalmaker12]

They come painted like that, there just centric wrx replacement rotors

[bnr32jason]

The stock WRX 2 pot calipers do produce more clamping force (on the same rotor, so more overall torque). The 4 pots are generally considered to have better 'feel', mostly because of the small change in pedal travel and possibly a more rigid caliper. The lower force in the front helps balance the F/R braking (for the better) in a stock WRX. I'm not sure if that will need to be the same in an 818.

For the 1800 pounds, and IMHO, even the stock WRX 2 pots are more than enough brakes. If a good pad selection is available, I plan to look into the single piston options on lighter Subarus. The 'small' 2-pots from the 2.5RS and the late '90s Outbacks might be a better/lighter option. Of course, for looks, most still prefer the 4-pots. FFR is also going to have a kit available from one of it's 3rd party partners, that is likely to be $$, but popular also.

I agree with your premise, that the lightest single option might be some tiny little OEM brakes, but I always laugh when I see tiny little brakes underneath big wheels. Now of course if you are going to be running stock wheels where you can barely see the brakes anyways, I guess no big deal.

If you are willing to spend the money, a nice set of Wilwood brakes to fill up some 17" or 18" wheels should only cost about 1200 and they are light enough to where when compared to even the tiniest Subaru OEM brakes the weight difference would be minimal (a pound or two per corner).

Just imagine a nice Porsche 911 with tiny little brakes, it's weird, it just looks so much nicer. Even though our cars are only going to be in the $15-20k range for most, it should still have some supercar looks to match the supercar performance.

http://image.europeancarweb.com/f/10878580/epcp_0811_05_z+POG_2001_Porsche_996_Turbo+Brembo_b rakes.jpg

[Xusia]

I get it, but I'm really laughing at the idea of monster sized brakes to complete the look. But small brakes prob would look silly. So maybe what we need are "poser" style fronts that just make the brake LOOK big! ROFL

[RM1SepEx]

Fake covers...

[PhyrraM]

If the car was designed around something like a 205/50R15 tire, most aspects of the car would perform better and OEM brakes would 'fill the wheel'.

I guess the social idea of what currently looks good overrule practical aspects. :p

[FFR-ADV]

Hi Wayne,

Keeping unsprung weight down by sizing the brakes to what the car needs makes great sense to me.

You mentioned in another thread using the Wilwood Dynalites all the way around. I found that Wilwood has Dynalite caliper brackets for the WRX rear brakes. Do you know of WRX Dynalite caliper brackets available for the front brakes? Any light disk recommendations? Thanks for your continued insight.

Dave,

Regarding color, do you have a timetable in mind for adding other colors such as Blue (my preference) and Red? If the color an 818 customer desires is not available at the scheduled delivery date could we schedule to pick the panels in the color we want later when available? Getting the rest of my 818 ready will still take time before I would need the panels and a two part parts pick-up would likely work for me. It is probably even better since they won't be in danger of getting dinged in my garage while the rest of the car is coming together. Glad to pay all up front and pick up the colored panels later.

The fit/finish your composites team is achieving is well worth the wait!

Sorry for the of topic side bar...

Cheers!

[apexanimal]

The stock WRX 2 pot calipers do produce more clamping force (on the same rotor, so more overall torque). The 4 pots are generally considered to have better 'feel', mostly because of the small change in pedal travel and possibly a more rigid caliper. The lower force in the front helps balance the F/R braking (for the better) in a stock WRX. I'm not sure if that will need to be the same in an 818.

For the 1800 pounds, and IMHO, even the stock WRX 2 pots are more than enough brakes. If a good pad selection is available, I plan to look into the single piston options on lighter Subarus. The 'small' 2-pots from the 2.5RS and the late '90s Outbacks might be a better/lighter option. Of course, for looks, most still prefer the 4-pots. FFR is also going to have a kit available from one of it's 3rd party partners, that is likely to be $$, but popular also.

Thanks... That's what I was recalling...

What's the difference btwn the wrx and 2.5rs 2 pots?

[PhyrraM]

Thanks... That's what I was recalling...

What's the difference btwn the wrx and 2.5rs 2 pots?

Mostly a smaller rotor. IIRC, about 3/4" smaller.

[Wayne Presley]

The stock WRX 2 pot calipers do produce more clamping force (on the same rotor, so more overall torque). The 4 pots are generally considered to have better 'feel', mostly because of the small change in pedal travel and possibly a more rigid caliper. The lower force in the front helps balance the F/R braking (for the better) in a stock WRX. I'm not sure if that will need to be the same in an 818.

For the 1800 pounds, and IMHO, even the stock WRX 2 pots are more than enough brakes. If a good pad selection is available, I plan to look into the single piston options on lighter Subarus. The 'small' 2-pots from the 2.5RS and the late '90s Outbacks might be a better/lighter option. Of course, for looks, most still prefer the 4-pots. FFR is also going to have a kit available from one of it's 3rd party partners, that is likely to be $$, but popular also.

I weighed the 2 pot fronts off the 05 WRX and they weighed 13 lbs each for caliper, bracket and pads.


Hi Wayne,

Keeping unsprung weight down by sizing the brakes to what the car needs makes great sense to me.

You mentioned in another thread using the Wilwood Dynalites all the way around. I found that Wilwood has Dynalite caliper brackets for the WRX rear brakes. Do you know of WRX Dynalite caliper brackets available for the front brakes? Any light disk recommendations? Thanks for your continued insight.

Cheers!

I think putting bigger rear brakes on the will work well as the weight balance on the cars is nearly reversed from the WRX. The Lotus' we race have the same rotor front and rear, 2 pot front and single rear OEM AP calipers.

[longislandwrx]

I think the H6 upgrade will be perfect for this car. The tiny rear rotors have always been the earlier WRXs Achilles heel. A proper pad choice with the larger rotors and I think it's a done deal.

I am hoping to do the Wilwoods for the weight, but if the price is crazy that will be my plan.

[Xusia]

I think the H6 upgrade will be perfect for this car. The tiny rear rotors have always been the earlier WRXs Achilles heel. A proper pad choice with the larger rotors and I think it's a done deal.

I am hoping to do the Wilwoods for the weight, but if the price is crazy that will be my plan.

Can you outline more specifically what you intend to do if not the Wilwoods?

[longislandwrx]

Basically using the Outback caliper bracket and rotor to get yourself another inch of Rotor. Factory calipers are used but you need an earlier 2002 model WRX pad.

http://forums.nasioc.com/forums/showthread.php?t=522006

The only Subaru part number you actually need is the bracket, although (Autozone does have a replacement now if you can find it for cheap - I'll try and find the part number) Everything else can be aftermarket... I'd get centric rotors and 2002 Hawk HPS pads.

http://forums.nasioc.com/forums/showthread.php?t=1824687

that thread has the Autozone info.

[Xusia]

Ahh. Gotcha. Thanks for the explanation.

[metalmaker12]

4 pot fronts, 2 pot rears, think they will work fine

[bnr32jason]

Now this is just a personal thing for me, but I don't want anything visbile on the car to say Subaru, the 4pot/2pot 06-07 setup is a no-go for me. I have no particular love or hate for Subaru, it's just that I want this car to take on it's identity as a Factory Five 818, not a Subaru based kit-car, even though I know that's what it is. I'll probably even replace the Wilwood stickers on the calipers with some "Factory Five" stickers or "818" or something.

The weight reduction and increased size are great benefits as well.

[Evan78]

Paint would take care of that issue unless you look pretty close.

[bnr32jason]

True, but then you don't get the significant weight reduction.

[RM1SepEx]

Pete! We'll launch in white but I'll keep options open for the second and third sets of production molds. As far as weight (the original topic of this thread) I was talking to the crew today about the 818S at Open House and we thought it would be cool to have the 818S drive into the event and up onto scales to show the "curb weight" We'll see. The boys are hard at work on the car right now.

timing for alternative colors????

[metalmaker12]

17893 Subaru is all over mine;)

[IMPREZvWRX]

Mostly a smaller rotor. IIRC, about 3/4" smaller.

Yep. The calipers are the same, with different brackets.

[Xusia]

Now this is just a personal thing for me, but I don't want anything visible on the car to say Subaru... ...I have no particular love or hate for Subaru, it's just that I want this car to take on it's identity as a Factory Five 818, not a Subaru based kit-car, even though I know that's what it is.

This is going to be my approach as well, and for the same reason. I really like what Erik [Treves] did with his:

http://thefactoryfiveforum.com/showthread.php?8899-2002-WRX-COPART-Teardown-and-now-CLEAN-UP&p=88192&viewfull=1#post88192

[RelfF2]

Now this is just a personal thing for me, but I don't want anything visbile on the car to say Subaru, the 4pot/2pot 06-07 setup is a no-go for me. I have no particular love or hate for Subaru, it's just that I want this car to take on it's identity as a Factory Five 818, not a Subaru based kit-car, even though I know that's what it is. I'll probably even replace the Wilwood stickers on the calipers with some "Factory Five" stickers or "818" or something.

The weight reduction and increased size are great benefits as well.

That's interesting, and will certainly make a cool car. I was actually thinking about doing the opposite -- really playing up the Subaru connection. Blue and yellow color scheme, subaru brakes...I'm also considering playing with the badging a little bit: instead of "FFR 818" I was thinking about changing it to "Project 818" with a "Powered by Subaru" somewhere on it. Instead of being just a Subaru based kit-car, i think the theme will be "the subaru prototype that subaru never built." I don't think FFR would be offended by this, one of the great thing about these cars is that there are an infinite number of ways to execute it. :)

weight is important to me, but i'm not too terribly concerned about it. As long as you don't do something stupid like put chrome 22''s on it or something, FFR has done the weight management work for us. 18'' wheels that balance weight and cost and Subaru brakes off a 06-07 WRX for me.

[PhyrraM]

Virtually every other (non-GTM) FFR is heavily intertwined with Ford. Sponsorships, decals, badges, etc. I think a few Subaru 818s can be a good thing.

An interesting tidbit, not sure if it means anything or not... At a local hot rod/car show this last weekend there were 3 Cobras. One was sporting plaques and signage stating that it was real, right down to a CSX (?) number and two Carroll Shelby autographs (one on a trunk panel and one on the dash). I'm pretty sure the other two were FFRs based on the exposed parts of the frame in the engine bay. Neither had any FFR markings on them. Not the nose badge or anything on the steering wheel. No FFR related literature around them either. All three looked awesome, but after reading these forums for the last two years I would have expected a bit of FFR pride to come through.