Turbo, Supercharger or NA 302

[snowdave]

I have acquired a nice donor and am spending the next couple years fine tuning it until we embark on the build. The donor is sprinkled with all sorts of bolt-ons and likely produces around 300 rwhp, so it is very lively and fun to drive. That hasn't changed my desire for more power/speed as I have spent most of my life on motorcycles and even quick cars seem slow/tame in comparison. I have decided on a goal of 400-500 rwhp as I want to stick with the stock block and keep additional costs low(ish). This leads me to my current topic/question; turbo, supercharger or NA?

Turbo
The On3 kits for a Mustang start around $1500 and my donor already has a pretty good fuel system to support it. The biggest drawback with turbos has not changed even with their current popularity.....packaging. I haven't spent much time looking at the Roadster engine bay, but would expect getting everything plumbed will not only be a PITA, but also custom/costly. I also like the idea of easy boost increases that can edge me closer to the magical 500 block splitting HP :-)

Supercharger
I know superchargers have gone out of style unless they are OEM/roots type, but there are several compelling arguments to charge a 302. The packaging is much easier, almost to the point of another bolt-on. Though cost/horsepower may not be as compelling as a turbo, if I look used/low boost (thinking Powerdyne here), it could just tick the boxes on my build. I had found a dirt cheap local one, but it fell through. I have another lead, but it is reaching my cost tipping point to jump to Vortech for all the known drawbacks. Low boost would still be ideal in my case as I am still hoping to stick with stock block/rotating assembly.

Naturally Aspirated
I would love to go this route, but it seems the most costly by far....and the worse cost/horsepower ratio. The idea of a stroker with some TFS heads has the appeal of a low-stress engine, so perhaps the combo will be more reliable and last longer. Also, less prone to bad fuel/tune that results in a blown up mess.

My intended use is strictly street use. I love banging through the gears and flying around corners, but nothing like the drag strip or road course. Perhaps I should just ignore this topic completely as the 1000lb weight loss going from the Mustang to the Roadster will more than satisfy my desire for more horsepower.....but knowing myself, I doubt it.

[Papa]

Snowdave:

I'm about as far from being an engine builder as you can get, but here are some things to think about based on your questions.

Turbo: With a 302 block, there is quite a bit of room in front of the engine for plumbing, but access to the exhaust side may be the biggest challenge. Also, most turbos I've driven bring power on fairly suddenly as the boost builds. This behavior in one of these cars would make driving it a challenge in my opinion.

Supercharger: The biggest challenge with a supercharger would be hood clearance. As long as you could keep it low enough, it could work pretty well. I've never driven a supercharged car, so I have no experience with how it feels as the boost comes on. Again, however, I'd be concerned with drivability as these cars are naturally traction challenged.

Naturally Aspirated: I have a Blueprint 347 (302 stroker) that is making over 400 ft.lbs. and 400 h.p. at the flywheel, which seems pretty easy to achieve with good parts. I suspect that I'm realizing around 325-350 h.p. at the rear wheels at my 6,100 ft. altitude. I've seen some approach the 500 h.p. mark. I haven't had my car on the open road yet, but just with my short drives around my neighborhood I can tell you that the power feels just about right. It's very drivable, but pulls like a freight train when you put your foot in it.

https://thefactoryfiveforum.com/attachment.php?attachmentid=84569&d=1524421786

I guess what I'm trying to say is that these cars are already a handful with the power-to-weight ratios they have. If your plan is to drive the car, take drivability into consideration before considering power adders.

Dave

[BEAR-AvHistory]

400+ horsepower to the wheels in a 2200/2300lb car means WOT can be very interesting. Old Chinese curse "may your life be interesting". Have 488whp NITTO drag radials in 35X17X315 & breaking them loose is a very very easy thing to do right through 3rd gear. These are short wheelbase lightweight cars with the power to weight ratio of a Lamborghini & none of the technology. I think most of the builds with current engines are easy sub 4 second 0-60 cars.

One of the guys posted this 0-60 on a GPS speedo

https://thefactoryfiveforum.com/attachment.php?attachmentid=100997&d=1548086189

Initially had thought about supercharging the engine but decided to see how N/A would go first. Saved myself an easy $7000.

You might want to watch some of the hotdog 1/2 shifts on YouTube.

[Jeff Kleiner]

Thinking that you want/need 400-500 RWHP in one of these cars tells me that you haven't yet driven one. Thinking that you can produce 400-500 RWHP with an OEM 5.0 block without it splitting down the middle tells me that you haven't yet done enough research.

Jeff

[cgundermann]

I am a Fox bodied Mustang fanatic and built/drove a number of them. Because I loved the “old school” 5.0 so much, I built my FFR Cobra with the ultimate 5.0 “go fast” parts. My wife disagreed and wanted a 427. My FI 347 is estimated to be 450 horses. As Papa stated, 300 horses make these 2300 pound cars a real handful. I retired after spending a full career driving fast daily. Not on a race track, but driving a heavier 225 horse 5.0 Mustang State Patrol car chasing “stuff” and training other State troopers. Takes a thief to catch a thief and I got paid to do what I love, and that was driving fast (legally). I say this not to alienate myself from those that have the need for speed, but to say I have the same obsession and that my specific Cobra is the only car that truly scares me and I honestly respect. Emphasis on being retired folks...

To your point, my car is so limited by functional traction - so 500+ horses is like using a double barrel shotgun to kill a rat. Don’t know your engine building skill level, but in terms of a STOCK 225 horse base donor motor, - mechanical simplicity and horsepower bang for the buck, in my opinion - a dated Paxton or Vortech supercharger is hard to beat.

Chris

[NAZ]

I'm sure you've heard the old saw -- buy cheap / buy twice. Most folks look at first cost and not the whole system. They don't think about the fact that anytime you make more HP you add heat and stress to the engine (remember, to get more power requires burning more fuel which adds stress not only to the engine but the cooling system too).

You can bolt on a lot of cheap HP to an OEM engine but without a good foundation (think forged rotating assembly at minimum) you will have to take a conservative approach or you may likely see the limit of what your bottom end can take. Engines designed to run boost typically have forged rotating assemblies, pistons & rings are designed for the additional heat and stress, the ring gaps are wider than a N/A engine, and even the style spark plugs are spec'd to shed heat faster than a typical projected tip plug.

Want more power? There's no substitute for cubic inches except cubic money. Turn that little engine into a bigger engine if you think you need more power. But you may be surprised how peppy that light car is with 300 WHP. Back in the muscle car days of the late 60's 300 flywheel HP in a 3500 lb car was considered fast. I was a Ford mechanic back when the big power Mustangs were popular and thought they were so fast. Today my lighter FFR machine with a moderate power small black is way faster than those machines from back in the day -- it's all power to weight.

[snowdave]

You might want to watch some of the hotdog 1/2 shifts on YouTube.

Have any links? I am guessing I haven't searched for the right thing. I have heard the combination of short wheelbase, 400+ HP and more weight in the rear does make these cars challenging. The one owner I spoke to and who took me for a ride did share his spin-out video from a track day, but wrote it off to having the brakes incorrectly balanced.

[KDubU]

I had a 351w and it had plenty of power. Just over 400hp on the dyno with a thumpy cam and would not change it. The only changes I would make is add a Weber’s or stacks. The reason I did not go with a 302 or 306 was concern over the block.

[TBull]

I drove a 400+ HP FFR Cobra for 10 years. It was supercharged 5.0L and like has been mentioned, it takes a lot of prep (forged piston and rods, main girdle, and all the other stuff). It scared the crap out of me when I first got it and I treated it with a HEALTHY respect, but over the years it became a known factor and you learn how to apply it and when. I then started adding more boost and got used to that. The Vortech supercharger starts providing boost even at low RPM since it's tied to the engine rotation. The power is linear to the RPM. Remember though anything over 5 or 6 pounds of boost and you'll need to have also include some type of intercooler(chemical, Air-To-Air or Air to Water). The centrifugal type of SC is easy to install, but you'll need to have a different ECU or at least someone that can add something like an SCT piggyback chip to have it tuned for the boost. It really adds a another dimension to the car, but one not to be entered into lightly. As you add more power you'll find other weak links in the drivetrain (Clutch, transmission, u-joints, Etc) I shattered 2nd gear in a T5Z and had to upgrade to a TKO-500. It's just things to think about and research as you move forward. Best of luck and I look forward to hearing what direction you take.

[GoDadGo]

These cars are not your average grocery getter so beware for what you wish for when it comes to turning up the power.

I was fortunate enough to meet a new Factory Five Family Member yesterday and took him for a short ride in my SOMEWHAT slightly over-powered project....He was a little surprised at how quickly the car accelerated and went into wheel spin in 1st and 2nd gear at someplace between 1/4 - 1/3 throttle with the rev-limiter kicking in at 4,000 RPM....Personally I think 300-400 HP would be more than adequate and a lot more drivable than higher powered cars producing 400-Plus which is where I am.

By the way, our new Family Member is Hjoensy and he just started his build.

[rich grsc]

Thinking that you want/need 400-500 RWHP in one of these cars tells me that you haven't yet driven one. Thinking that you can produce 400-500 RWHP with an OEM 5.0 block without it splitting down the middle tells me that you haven't yet done enough research.

Jeff

I want ridiculous HP, really cheaply. Sounds similar to the job I'm looking for, High Pay, no work involved . :rolleyes:

Hey, just kidding around some, but 450-500 hp in these cars without some driving experience, sounds like a disaster looking for a place to happen.

[cgundermann]

I completely agree with Naz & TBull. And I should have been more specific in terms of entry level boost. The initial question was value and power adders.

The old basic Vortech/Paxton kits started at 5-6 PSI and could be had for several thousand dollars. A donor 225 horse 5.0 with this entry level boost gave you 100+ horsepower. IF you kept it within the 375 horsepower range (give or take) the internals and running gear held well enough IMO. More than enough in these cars. Higher levels of boost Naz hit it on the head.

Chris

[BEAR-AvHistory]

Have any links? I am guessing I haven't searched for the right thing. I have heard the combination of short wheelbase, 400+ HP and more weight in the rear does make these cars challenging. The one owner I spoke to and who took me for a ride did share his spin-out video from a track day, but wrote it off to having the brakes incorrectly balanced.

He should have written it off to dumb driving. Have had my own Oh! S**t moment on a 1/2 shift but was able to ride it out. Was a bit too cold for the tires & the shift was a bit too hard even though not at WOT. Rear jumped out quite a bit.

As for the vids search Cobra bad driving, crashes, wrecks, screw ups etc. I come across them on occasion.

FWIW the best thing you can do with one of these cars is day 1 hit a empty big box parking lot early Sunday morning & find the edge. Local Auto-X events are great for shaking down the car.

No one should get so caught up in the "what if" so that they drive scared the car, a really bad thing to do is drive afraid, but just respect that it will react quicker them most anything else on the road to intended or unintended inputs. Cars with similar power to weight ratios today all have a lot of nannies these cars don't have. Only the one between your ears.


https://youtu.be/YAmbhWLcWew

For my usage a supercharger would be as useful as tits on a bull. Great for opening the hood while parked, not so much over the road.

[Shep]

I built a MKII about 10 years ago. Well built 5.0, lots of aftermarket goodies. Ran it NA for the first 18-24 months, then dropped a Kenne Bell on top of it. Dyno'd at around 410 rwhp. As a NA car it was fun to drive and you quickly learned to treat it with respect. As a supercharged 400+ HP car, it was an absolute beast, crazy fun to drive, but you sort of felt it was always ready to turn on you!

[j.miller]

Brother you are hearing it from experts on these cars. I have been around these for 20 years. There is the "never can have to much HP" crowed (gotta love them crazy somesabishes) and then the guys who want to drive their car and not have their car drive them. I jus love, love, love a 220 hp 302 with 80k miles on it, slap on a powerdyne with 5psi and go play.....problem is, PLAY means different things to different people. One of my customers (god love him) had 500 to the rear wheels...Big Block ! His idea of fun was a 200yd burnout UPHILL. Dangdest thing I ever saw (dude it was steep) Good luck with your choice.....my only word of advise would be. (What you think you want) + (What you think you need) - (your bank account) + (your driving ability) X(speeding tickets) ….carry the 2...multiply by .4371.....and there you have it in a nutshell ! And you are welcome ! always remember do the numbers in parenthesis first. I bet by now you are happy you asked ! ...da Bat

[Ray]

We've got a carb'ed 302 with no power adders. Just north of 300-hp and it's plenty fast and quick enough for me. I drove fast, on the streets for a living and this car is more than enough for me. Turbo's, superchargers, NOS etc. in my opinion, just add complexity and expense. But, to each their own.

Ray

[cgundermann]

Just read this polite British article and it reminded me of this thread:

101103

The caption underneath it stated:

“If you look very closely at the driver's face, he is trying to mask the fact that he has completely soiled himself”.

Lol...

Chris

[caesarmascetti]

just my two cents IMO a 347 (302 based) is the optimal combination for this car. I'm biased because I have this in my car. It puts out 412hp and will scare the sh*t out of you if you really nail it. Its compact fits the engine compartment well, is a little lighter than 351 based power units.

[BEAR-AvHistory]

Just read this polite British article and it reminded me of this thread:

101103

The caption underneath it stated:

“If you look very closely at the driver's face, he is trying to mask the fact that he has completely soiled himself”.

Lol...

Chris

Fact the he is driving a left hand drive car on the wrong side of the road most likely does not help his frame of mind.:D

[snowdave]

The comment regarding Youtube fail videos has sent me on a research trip that really illustrated how scary the handling of these beasts can be (poor setup, inexperienced driver, massive power, etc). I would equate it to the issues experienced riding a superbike, but even then, the superbike is built and initially setup by a factory of skilled technicians and engineers. I am naively equating my current Mustang driving experience to what I can expect from the Roadster, when really they will be completely different. The Mustang is predictable with smooth power and when it lets loose, it does so consistently and a little less gas or short-shifting brings it back inline. My issue is that I am ready for more power in my Mustang after just the first year of ownership. If the right used/cheap blower comes up before we order the kit, I will buy it. It will be the most cost effective option for my current setup/situation. If it turns out the deal that fell through was a once in a lifetime, too good to be true deal, then I will find out just how fun it can be with the engine as-is. Naturally my idea of as-is includes continued tuning and a potential refresh when it gets swapped over :-)

[GoDadGo]

Snowman,

You have no idea what you are in for so maybe this video will give you an idea:

https://youtu.be/V96-AQ1FghI

Just understand that the drag strip was prepped very, very well when they shot this video. ...Also, the Ridetech FF-33 Won The Optima Street Car Challenge and now only production cars that came from a factory that were born with a VIN are allowed to compete.

Again, you have no idea what you are in for so build what you want, it is what we all are doing.

Good Luck From The Dark-Dart Side!

Swampland Steve

Correction: Finished 3rd
https://www.factoryfive.com/whats-new/ridetech-factory-five-33-hot-rod-finishes-3rd-in-optima-challenge/

[DadofThree]

I'd like to chime in as a low hp stock 302 w/ 3.08 rear.

I was getting caught up in the higher HP feeling when starting my build. But realized that if I don't have a stock starting point, I won't have anywhere to go up. And if the starting point was enough for Ford to call it a Mustang GT, who am I to decide I need more HP for a car that's 1,000 lbs lighter with a tighter wheel base? So I stayed stock to learn the car.

Having the low hp / low torque has saved my Inexperienced Butt. Twice.

One beautiful day I was "needing" to get out in front of traffic as I turned right onto a 4 lane road as the light turned green for the traffic I was jetting out in front of. Pressed the gas, and away I went like a rocket while changing lanes to go around a slow bus on the right. The car pressed me in the back of the seat as I listened to my favorite rev range in 2nd gear. I shifted to third, and moved to the right lane to cruise.

It wasn't until I passed the bus and made my way back in the right lane did I realize that THAT was one of the scenarios where I would have put it in the ditch if I had excessive (for me) HP in my car. I didn't think before I hit the gas, I just did it.

That lack of thought and knowledge is what could have put me in the grass. I would have been surprised by the excessive torque that I'm not used to driving, and unable to handle or correct what I had just done. Having the low end saved me. I still need to learn how to drive and respect the car before adding my extra HP.

Best Regards,
Dave

[Boydster]

... I am naively equating my current Mustang driving experience to what I can expect from the Roadster, when really they will be completely different. The Mustang is predictable with smooth power and when it lets loose, it does so consistently and a little less gas or short-shifting brings it back inline....

Take that Mustang and remove 1500 lbs.

I have about 15 miles on my go-cart (427W) and with sticky tires (Nitto NT05, 315x17), it'll stick for a good bit, but when it goes, it snaps loose fast.
With these cars, its all about control.

[RickP]

Snowdave - seems like your getting great feedback from everyone. Albeit we LOVE to spend others money, there is a practicality aspect to your aspirations. Setting a goal of a horsepower mark is the wrong way to look at this. Horsepower does not equal fun, torque does. A properly geared, setup driveline, coupled with even a stock 302 equates to a very robust power package in these cars.

hey, I get the whole HP thing. However, be realistic in how you intend to use the car. If it's bragging rights at the local show n shine your after, we can very easily help you spend your money. If it's dependability, drivability, and whole lotta fun your after, I suggest you take a more realistic and practical approach during this planning phase. Just bolting on a power adder of any sort on top of a foundation that can't support it is going to cause you headaches down the road (no pun).


Build the foundation of your block as robust as you can afford and take the extra money you would spend on a super charger or turbo setup and apply it to the rest of your driveline. If in the future, you want more power, at least the foundation will already be addressed.


RickP

[Dave Howard]

Snowdave - seems like your getting great feedback from everyone. Albeit we LOVE to spend others money, there is a practicality aspect to your aspirations. Setting a goal of a horsepower mark is the wrong way to look at this. Horsepower does not equal fun, torque does. A properly geared, setup driveline, coupled with even a stock 302 equates to a very robust power package in these cars.

hey, I get the whole HP thing. However, be realistic in how you intend to use the car. If it's bragging rights at the local show n shine your after, we can very easily help you spend your money. If it's dependability, drivability, and whole lotta fun your after, I suggest you take a more realistic and practical approach during this planning phase. Just bolting on a power adder of any sort on top of a foundation that can't support it is going to cause you headaches down the road (no pun).


Build the foundation of your block as robust as you can afford and take the extra money you would spend on a super charger or turbo setup and apply it to the rest of your driveline. If in the future, you want more power, at least the foundation will already be addressed.


RickP

Sounds like a Coyote is what Snowdave needs to satisfy his own needs and respond to all the great comments. They are easy to drive at lower RPM. They are crazy powerful at the mid-range through redline. They are tough as nails. Easy to install and the properly tuned ECM looks after the engine performance. I just doesn't look like your conventional pushrod SB/BBF.

[JEMAN]

I have a 306 with AFR heads, cam and such being run on a FAST XFI 2.0 multi port setup in my 33 hotrod. I was thinking I needed a 351 with big power but ended going with a 302 based motor. I will just say that I am surprised by the power and head snapping fun I have in the car. What I guess I am saying is these cars do not need the power which we are a custom to striving for in the regular mustangs, camaros, corvettes and etc. This was my first light weight kit car so I did not know what to expect but these light weight cars can blow the tires off pretty fast on you. I have had plenty of big power cars with all the suspension and traction supporting mods needed from mustangs to imports that were up anywhere from 400- 800 hp with 13 - 28 psi of boost just to let you know that I have a reference and do not come from only driving Prius's

Honestly if you have time before your build I would keep an eye out for a new wrecked mustang part out and take the coyote out of it. will give you plenty of power and do not have to worry about added height clearances, added heat from turbos and exhaust routing. I have been seeing a few good part outs lately anywhere from $4,300 to $6,100. just have to wait for the deals which you write you have time. Look for insurance auto action sites to source part outs too. This will be the route I would go on the next build

[BEAR-AvHistory]

Coyote fills that hole between the fenders quite nicely.

https://thefactoryfiveforum.com/attachment.php?attachmentid=101143&d=1548213822

Based on budget its comes in multiple flavors.

Various horsepower brand new warrantied crate engines from FORD Racing.
Used engines from various model year Mustangs
Used engines from various model year F150's

Before discounting the F150 Coyote out of hand they usually have a very good pricing compared to the crate or Mustang GT & the oldest series start at 360BHP going up to 395BHP in the 2018 truck. That gives you 5.7LBS per horsepower similar to the 2017 Corvette Z06.

[snowdave]

I have to say there is almost zero chance of a Coyote (or any other mod-motor Ford) making its way into my Roadster. As a longtime Ford blue guy, it is sacrilege, but I would likely drop in an LS before any of the newer Ford V8 options. I've had a 289, (2) 302's, (2) 4.6's, (2) 5.4's in a variety of cars and trucks. My latest (and perhaps last) was a Triton. If I could take the engineers responsible for that out for a good long drag behind my car, I would. While the Coyote is much improved, it still has many of the same design elements that made the Triton such a piece. Since engineering superiority was my initial reason for going Ford, it is now my reasoning for loving on the LS-motors.

Regardless, I am quite happy with my choice for an old school 302 (sounds funny as it is 25 years newer than my 289 and EFI). I know all about the weak block and realize it's limits and I am willing to work within them.

[NAZ]

While I have already weighed-in here I will also state that I am solidly in the "Can't Have Too Much Power" camp. That skinny pedal modulates the power -- if you haven't developed the discipline to use it wisely then perhaps there really is a thing called too much power for some.

My advice was centered around building a solid foundation if you think you need more power than the diminutive 302 can produce in it's OEM form. And since you are new to these light weight cars, I wanted to add that the power to weight factor will make up for a lot of HP shortcomings from the little 302 and will probably surprise you how much fun even a modest amount of power can provide. It's always less expensive to build a modest powered car than a high HP car.

However, since you know about the block's limits (and assuming that you should also know the limits of the rotating assembly) then it would seem odd that you'd elect to supercharge it in its OEM form. It will take about 7 or 8 PSI to really feel the extra power in the seat of your pants when starting at ~300 HP. Boost a 302 to 7.5 PSI and it will feel like you have a 450 CI engine (~50% larger) -- that's right, not quite earth shaking but can your stock engine reliably handle that much boost? The supercharger is a fixed cost regardless of the amount of boost you extract from it so your $$/HP will look much better at 12 PSI than 3 PSI.

Now RickP has some good advise but I'd add that if boost is in your future the foundation build should include the appropriate CR and ring gap to support a future power adder. And while you're building a solid foundation for the future remember it only costs a little more to go bigger and bigger is always better. And all of your drivetrain must be capable of handling the extra power you want to add.

[GoDadGo]

Regardless, I am quite happy with my choice for an old school 302 (sounds funny as it is 25 years newer than my 289 and EFI). I know all about the weak block and realize it's limits and I am willing to work within them.

Or You Could Join The Dark Side Instead!

https://youtu.be/wOID7yvBRPU

I'll send THE NAZ my mounting dimensions and I'm sure he can stick one in for you!

[dwheeler]

I think about a supercharger once in a while. Then I get reminded that I don't need it when I actually floor it once or twice per year. It's scary at 300 hp when you release the beast.

I tell people that I have more power and braking than traction. You'll want R compound tires if you go more than 300 hp.

[FlyingCobra]

Reasons I'm going N/A:

1) To minimize the weight in the front (and weight overall).
2) To keep the engine as responsive as possible. I'm not a fan of turbo lag. Even superchargers, while essentially lag-free, still add some rotating mass and hurt responsiveness

[NAZ]

Steve, too bad we don't live closer to Dave as between the two of us we could help him stuff a stroker SBC in that thing that would make more power than a base 302 SBF even with a blower. And he could get his Dark Side club card.

[snowdave]

I have owned a built 350 also that I put in a Malibu and was unimpressed (also didn't like seeing it burnt to the ground in Ogalala, NE). The SBF was always a better engine to me than a SBC and I liked that not everyone had one in my high school days. Times have changed and the LS is arguably the best of the current options, it just veers too far away from the original Cobra (or at least lacks official FFR support). The nostalgia I get driving the Fox Convertible I could never afford in school also helps. As to cost, I currently have less in my whole donor than what many will have in just their motor, and that is the way I like it :-)

[GoDadGo]

Dave,

If you go with a healthy 302 SBF you won't be able to wipe the grin off of your face because it will be quite fast....Also, we were just messing with you about joining the Dark Side, but if you want to go down that path I'll share everything I know....

One suggestion I have is to please invest in a good oil pan and pick up that puts the sump towards the rear of the engine since that is where your oil will end up under acceleration.... In addition, going with the 302 gives you the easiest build option since no fabrication will be requires plus you end up with a nice amount of under hood room.

Steve

[caesarmascetti]

one more vote for the 347 stroker, it will make all the power you want and it fits so well. IMO it just looks right, never mind the sock:

https://i.imgur.com/zXELpej.jpg

[snowdave]

While I agree the 347 is a good solution, I don't think it is cost effective for me. The stroker kit is at least $1000, I assume another $500 in machine shop work and my current heads are ported GT40Ps, which should really be replaced for a bigger motor, so add another $1500 for TFS 11r heads......$3000! I will likely need new headers and a cam at the same time. I have looked for a used stroker short block or even rotating assembly, but have not seen one I would trust.

As an aside, I am hoping to get the 11r heads down the road. I just realize that the ported GT40Ps that I have now is actually a well matched setup to cam, intake, etc and don't expect a massive power jump from heads alone.

[frankb]

Snowdave: You are a bit light on your estimate of machine work...Mine was closer to $1,500 not including some special machining that I had done to my 351C. I will join others in saying build for a power adder with ring gaps, piston clearances, etc, build and drive the car NA for a period to get used to its handling, then if you still want more HP, add the blower! These cars are scary fast!

[Avalanche325]

I have a 500hp (at the crank) 347. It can get angry in a hurry. But, when I autocross, I can use it all a few times during a run. My setup, would probably be at the "just streetable" level. It is snotty and temperamental, and even with Flowmasters VERY loud. Part of the fun to me. Other people would hate it.

The very very fist thing to do to a Windsor is to put aftermarket heads on it. Sorry, but if you are looking for HP, there is no Ford factory head that is up to the task no matter how much you port it or what valves you put in them.

If you want 500+ RWHP (575+ at the crank), you had better think about a BOSS or DART block. Or keep a broom in the trunk to sweep up the parts.

[GFX2043mtu]

As avalanche said 500 whp in a stock 302 block comes with a broom, dustpan and a mop. The 302 is a thin wall casting like that of the 289. These motors where made to be light and produce reasonable power. With that said I’ve seen my share of split blocks. The problem is there is no stead fast number to where they fail and no stud girdle or hardware change can fix the or reduce the issue. Point blank any thing much over 400whp is starting to be a dice roll. At 500whp your on borrowed time and a block upgrade would be cheap insurance at that point. It may last a couple years it may last a couple of dyno pulls. Be reasonable, if you want 500 hp cheep get a used 351 with a set of heads and a used blower. If your fine with stopping at 400 whp (460 chp) use the 302 and keep the revs 6k and below. As many have said 400 whp is a lot in these 2200-2400 lb cars. I’m running 650 hp and 650 ft-lb at the crank and unless you have some racing time in some very very high power to weight cars with zero aids, the learning curve is that of Mount Everest. when things start to go wrong it goes fast. At that point you have no time to learn you must react. More importantly you need to know how to to feel the car so you know how to approach the limits and stop on that line in a safe environment. That’s what makes a car like these truly fast, as it’s not necessarily the power rather it’s the driver. I built mine for track use and some street use and I’ll tell you my car had no hook up point on the street where you can go full throttle with a reasonable degree of safety. I usually go 25-50% and that’s all it can hook up in the first 3 gears. I’m not sure where your from but if your in Michigan I can give you a ride in the spring and you’ll see exactly what I’m talking about. I run and race 1000cc modified class sportbikes on the race track in expert and this this car is just as much of a handful.

[snowdave]

All very good points that are still pushing me toward a low boost blower on my existing combination. I agree that the engine should be setup for it, but luckily ring end gap and forged pistons are free :-) I have considered the 400 vs 500hp argument regarding the stock block and although I like the sound of shooting for 500, listening to all the warnings of high power in the Roadster chassis, I am pretty sure I will be plenty happy with 400 or even slightly less. I also understand a number of other factors often enter into block splitting (high boost, poor tune, hard launches, high rpm, etc, etc). BTW, if you guys like tuning your own, I have really appreciated this guys wealth of knowledge: http://www.efidynotuning.com/ A bit dated for current setups, but awesome for the old Foxbodies.

Also, thanks for the bike comparison. I have spent plenty of time on dirt/mx tracks, but never made it to the road course. I even have a dedicated SV650 track bike, but ended up with a broken back before I made my first session. I have thousands of miles on my Ducati 996, but on the street you never come close to testing its potential......except for that trip through the Pyrenees on my ST2. I had the brakes and clutch smoking after that one. All of my bikes have been very consistent though, the only one that ever tried to kill me every time I rode was a YZ450F. It was the only time I actually felt you could have too much power, or at least the wrong kind of light switch power. That bike only knew two modes, front wheel in the air and rear wheel sliding out sideways.

[3yearplan]

Unless you run drag tires, or really, really, really sticky tires, hard launches won't be an issue. You'll spin the tires for three gears. But to the point of a low boost supercharger, I run a Vortech V1 S-trim (if I recall correctly) on my 360 Dodge Dakota. It's Mopar Performance short block with ported and polished factory iron heads, 4 barrel EFI intake. It dyno'd at 345 at the rear wheels on 8 pounds of boost. It's very similar to these cars in respect to traction, obviously not weight. I know a 360 is more in line with a 351. I haven't driven my car yet (bone stock 2004 Mach 1 DOHC 32V) but I'm not even concerned about USABLE horsepower. I rode in a 450 horsepower FF and like the others said it was wheel spin city through three gears. It was fun, but not the fastest way from A to B. But like we always say here build what YOU want.

Mike

[1932]

That is what the right pedal is for, just because you have the HP does not mean you need to pedal down when it is not safe to do so, and take time to learn your car.

[johnnybgoode]

IMHO it's torque that makes these cars fun vs HP. A mild 408 is hard to beat and makes the right sounds. Scott

[snowdave]

I must admit that while I like power and high speed on my bikes, I most enjoy tire spinning mayhem while banging gears in the Mustang. It is best if it lasts from first through third gear while accelerating predictably (though not necessary quick or most efficiently). Since this already works in the Mustang, I am assuming it will also work in the Roadster. I figure the 100hp+ that the supercharger will add would just add to the tire spinning and the ability to pull 3rd/4th better. I am now slightly apprehensive that the short wheelbase will change the predictable wheelspin with something that will quickly put me in the ditch.

[1932]

In a light car i do not see the use of a lot of torque, so i went for HP. All the torque is no good if you can't get it to the road.

[BEAR-AvHistory]

Agree. Tuned the Coyote to back some low end torque out & push the horsepower further up the rev range.

[snowdave]

With the crazy low price of an On3 Mustang kit, has anyone successfully installed one on a Roadster? As much as I am still leaning toward the blower for the reasons above, the idea of a $1500 turbo (if fitment isn't too painful) does still have some appeal. A search of this forum did not find anything (though I may have just missed it).

[edwardb]

I must admit that while I like power and high speed on my bikes, I most enjoy tire spinning mayhem while banging gears in the Mustang. It is best if it lasts from first through third gear while accelerating predictably (though not necessary quick or most efficiently). Since this already works in the Mustang, I am assuming it will also work in the Roadster. I figure the 100hp+ that the supercharger will add would just add to the tire spinning and the ability to pull 3rd/4th better. I am now slightly apprehensive that the short wheelbase will change the predictable wheelspin with something that will quickly put me in the ditch.

You are right to be concerned about putting it in the ditch. With the short wheelbase and zero electronic assist, these cars don't respond well to constant wheel spinning. Unless you're doing donuts in the parking lot. For "normal" street driving (which means different things to different people, I realize) you will be hard pressed IMO to use more than 300-400 rear wheel HP. At that point you're already sub four-second zero to sixty and almost instantly illegal everywhere. It's all about traction, setup and driver. Supercharger, turbocharger, whatever... Nice conversation pieces at car shows and such.

[GoDadGo]

You are right to be concerned about putting it in the ditch. With the short wheelbase and zero electronic assist, these cars don't respond well to constant wheel spinning.

Edwardb Makes An Excellent Point!

If you look at this video, at or around the 2 minute mark, you'll see I've got no traction and the car is between 1/4 - 1/3 throttle in 1st gear. If you listen to it closely, or slow the video down, you'll hear me pedal the sucker a few times as I go down the street.

https://youtu.be/PCngiKoopkA

In addition, when I had to replace my engine block, which is another story, I actually changed the camshaft to reduce duration so I effectively took away some power while improving lower speed manners. The problem doing that is it makes even more power at the lower end of the RPM spectrum.

Build What You Want But Be Careful!

[Avalanche325]

I always recommend autocross for owners of these cars. It is a great place to run 100%, find and exceed the limits, while being safe. Not to mention a lot of fun without a lot of expense. As mentioned above, the short wheelbase and no driving aids can catch people out. Often people start getting in trouble, do a abrupt lift and put themselves all the way in trouble.

Watch the 2nd gear grab. Notice that I short shifted big time, not at full throttle and it still jumps sideways. The tires are 180 treadwear, so pretty sticky. That whooshing sound throughout the video is wheel spin. I had someone think it was a turbo.
https://youtu.be/o_Qwhu9Ma0o

[BEAR-AvHistory]

You are right to be concerned about putting it in the ditch. With the short wheelbase and zero electronic assist, these cars don't respond well to constant wheel spinning. Unless you're doing donuts in the parking lot. For "normal" street driving (which means different things to different people, I realize) you will be hard pressed IMO to use more than 300-400 rear wheel HP. At that point you're already sub four-second zero to sixty and almost instantly illegal everywhere. It's all about traction, setup and driver. Supercharger, turbocharger, whatever... Nice conversation pieces at car shows and such.

Yeah thats the bottom line: power to the ground. Had always thought I was going to get a supercharger. Got the car built & tuned N/A. After break-in miles found out that even with 13" wide drag radials using 100 treadware rubber can't hold WOT traction till every speed law in the country is broken. Maybe some sandbags in the trunk:rolleyes: