I'm interested in talking to who is making more than 450hp or if anyone here has a turbo/supercharged V8? I'm sure it's absolutely a blast to drive, but what is the throttle response and acceleration like. Did you have your transmission beefed up? I realize the stock craddle works but has anyone built a custom craddle to house the motor in the Fiero? I'm asking these questions because I'm designing a car to build. The engine tranny configuration in the Fiero is what I have decided to use for the car. I just need the performance stats on the V8 setup.

Thanks

V/R
John

Well, neither of these are my car :whine: BUT

I was really impressed with the LS4/4T65E-HD swap that Darth Fiero did for BLKCOFY's car
https://www.fiero.nl/forum/Forum3/HTML/000087.html

There are a couple of turbocharged LS4's around in w-bodies, I understand that GXPJAY ultimately managed to dyno 505hp at the wheels with his Cartuning LS4 turbo kit. Buried somewhere in this thread is a video of a 465/465 whp/wtq dyno run.
http://www.ls1tech.com/foru...s4-turbo-update.html

Cheers

[This message has been edited by TiredGXP (edited 03-15-2009).]

R Runner's car makes 645 HP. Of course, it's a race car, and not street legal.

I've seen another one on here, it's an Indy Pace car with a procharged SBC and a Getrag with a fabricated cage around the diff.
Black coffee's car wasn't boosted, but had 271 rwhp and ran high 12s on 265/35R18 street tires.

MM Can you say the X-Machine????? you know (Fierox) i think his last setup was something like 650+rwhp

how do you keep your trannys from exploding at thos high hp engines?

Mostly from driving carefully. Cryo-treating seems to be some help, and choice of fluid might contribute something.

IMO putting that type of horsepower in a Fiero will cause it to exceed or get dangerously close to the design limits of the cradle, mounts, rear tie rod, lower rear ball joint, strut etc. There is a girl by the name of Tina on this forum who drives a Fiero with a bonzai V8 and I remember reading that shes broken a few things along the way. As for 450 HP behind the Getrag- drive gently.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE WILDCAT"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Most the V-8 guys are making at least 450 HP or more I am sure--Better bolt that type of HP to one of the new 6 speeds so you can have plenty of trans to put that much HP to the ground.

destop dyno says i am making 814 hp at 6,000 and 819 lbs torque at 5,000 rpms. I think that's a bit optimistic but still it's over kill. I had a thm 325 that was built and it only lasted a short time under full boost before it just slipped the clutches and burnt up the trany. I now have a new highly built thm 425 from a 78 eldorado. I cant tell you how it drives as it is not quiet done. short detail of my engine its a 355 all forged rated to 1,500 hp and 10,000 rpm has blower cam 1.6 ratio rocker arms o ringed 200 cc heads demon blow thru carb a pair of t4 turbo with upgraded (larger compressor wheels) boost controled at 18 lbs. my new trany has a 7 inch converter with 3500 stall and 3.42 gears and complete build by trans shop. you can't see it but i have 6 engine mounts and beefed up cradle and frame rails

That's insane! How do you put that much power to the groundon such a light car? What size tire are you running?

it spins alot also since it's pushed to the back of the car there is more weight on the rear the front end gets realy light. I think with more traction i could raise the front tires. i have 275 35 zr17 toyo

Most of the 11 second 3800 cars are making around 400 crank HP. fierox made mid 400's with nitrous to the wheels, which would equate to 550-600 crank HP.

I had a 800hp rodeck in my z28 ..in a stock Fiero chassis it would be insane if it could hooke up and would probably cause breakage ..I bet TroyBoy will soon be able to tell you what 500+ Z06 hp is in a Fiero in the not distant future ..Fierox can as well right now and IIRC, his has mods to the chassis to withstand the forces ( multipoint rollbar and other mods)

[This message has been edited by Erik (edited 03-16-2009).]

I am putting down 415 HP to the wheels which is probably in the 450 HP crank region. I can tell you that the Getrag/Muncie 5-speed has reliability issues with this power level. If you plan on using all the power, plan on replacing the trans often. I get about 10k miles per transmission.

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62 Buick Special
86 GT, 5-Speed
87 GT, 3.4l DOHC Turbo 415 WHP, 11.9 @ 118
88 Toyota Supra Turbo

look at Troyboy's build Archie installed an LS7 / 6speed in his car.
Archie and others have done many builds with way more than 450 hp.
it just depends how big your pocket book is! LOL

[This message has been edited by whodeanie (edited 03-16-2009).]

Sounds like the tranny is the single point of failure (SPF). Has anyone thought about building a custom tube chassis that could be installed with a V8 and different tranny in the same configuration as the Lambo? I know it cost money to make things happen, but if you could weld and bolt on a complete custom rear that included a V8 motor and tranny and better suspension (corvette maybe) that would give you 450+ reliable power...that would give you a huge advantage over the stock setup. The question is would that setup require you to have a body kit installed to cover the added length. The cost factor..... would it be worth it. You could sell the chassis alone with suspension parts in place or sell it with the engine with the adapter for whatever tranny you may be using. Just an idea.
Has anyone taken a stronger FWD tranny and mounted it to a V8 for more power?

[This message has been edited by SST (edited 03-16-2009).]

Someone just posted in your thread with a picture of a TH425 trans used in the old FWD cars.



The transverse transmission most are using now, is the 4t65e. It is the stock automatic that comes in bonneville's and grand prix's.

Stock they hold 300-350HP without trying, mild mods doubles that, some more extreme mods will double that.

No manual trans is really up to the task.. Mostly due to gear ratios and clutch options more so than strength.

So how much more does the car need to be lengthened to accomadate the motor/tranny transversly?

[This message has been edited by SST (edited 03-16-2009).]

quote Originally posted by MstangsBware: Most the V-8 guys are making at least 450 HP or more I am sure--Better bolt that type of HP to one of the new 6 speeds so you can have plenty of trans to put that much HP to the ground.

You forgot to add the sarcasm emoticon ...those that don't know you might think you are serious.

quote Originally posted by darkhorizon: Someone just posted in your thread with a picture of a TH425 trans used in the old FWD cars. The transverse transmission most are using now, is the 4t65e. It is the stock automatic that comes in bonneville's and grand prix's. Stock they hold 300-350HP without trying, mild mods doubles that, some more extreme mods will double that. No manual trans is really up to the task.. Mostly due to gear ratios and clutch options more so than strength.

what mods should be done and who (in central Florida) could do them?
I DO NOT trust my locals (34608) to change my oil let alone trust my 4t65e.

Hi.

If you have the $, G-force transmissions makes a universal drag race transaxle that'll hold far more than anything else commonly used for serious Fieros.

quote Originally posted by Isolde: If you have the $, G-force transmissions makes a universal drag race transaxle that'll hold far more than anything else commonly used for serious Fieros.

Its not just the trans.There are sevweral trans choices that can take the power. Its the strut /towers, rear ball joints, rear tie rods, control arm and cradle. They were not designed for unlimited horsepower. Sure you can pop in a 500HP engine but I would say some reinforcing mods would be needed if you intend to stand on it.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

quote Originally posted by Dennis LaGrua: Its not just the trans.There are sevweral trans choices that can take the power. Its the strut /towers, rear ball joints, rear tie rods, control arm and cradle. They were not designed for unlimited horsepower. Sure you can pop in a 500HP engine but I would say some reinforcing mods would be needed if you intend to stand on it.

So, building your own chassis to house whatever engine/tranny combo with a corvette or whatever suspension of your choice is probably the best way to achieve what I am looking for? Not that all the other options are not good choices....but for my particular project this may be the way to go.

The 88 rear suspension doesn't use ball joints. The rear links can easily be duplicated in a higher strength form if you're worried about poly bushings.

Most of the V8's?? I think not.

John Stricker

quote Originally posted by MstangsBware: Most the V-8 guys are making at least 450 HP or more I am sure--Better bolt that type of HP to one of the new 6 speeds so you can have plenty of trans to put that much HP to the ground.

404: Sarcasm not found

quote Originally posted by Dennis LaGrua: Its not just the trans.There are sevweral trans choices that can take the power. Its the strut /towers, rear ball joints, rear tie rods, control arm and cradle. They were not designed for unlimited horsepower. Sure you can pop in a 500HP engine but I would say some reinforcing mods would be needed if you intend to stand on it.

Obviously there are weaknesses. You have no idea what they are because you haven't broken any parts yet. Strut towers a weakness for power? Draw out a free body diagram of the strut and tell me what drive loads the strut tops transmit to the body.

Id say it has to be an inline engine and transaxle. FWD style just dont have the beef for big block stuff. Mid 60s Mopars put out over 700 hp stock from showrooms (425 valve cover decals were a joke) and their 4 spds and automatics were still nearly bulletproof. With inline, you can go with ZF trans. I may be wrong since I dont follow drags much, but I cant remember ever seeing or hearing of any funny cars or rails that tried a transverse setup. If you want it to stay looking Fiero, build your own tube frame with the correct wheelbase and just use the body panels. I think one member here does have an inline 455 Pontiac, but dont know his trans setup.

My V8 Fiero originally had a 383 stroker with just around 400 hp. I couldnt get pro built TH125 to last more than 1,000 miles on the street...never went to the track. We tried all kinds of TCs, stainless, fiber bands, high pressure pumps and valve body, and as many as an 8 disc clutch pak. I went thru 3 in less than a year, swapped in a stock ZZ4 small block and still blew tranny up in 1,000 miles. I did break a couple of CV joints and axles along the way also. I got so pizzed in the end I sold the $20,000 car for $5000 at a classic sale.

If I remember, Tina blows apart about 2 transmissions a season.

[This message has been edited by rogergarrison (edited 03-17-2009).]

quote Originally posted by Will: I haven't run a lot of power in an '88 yet, but I would think that you'd want to leave the trailing arm bushings rubber to leave some compliance in the system.

Agreed... That's what I did for my SBC 88 back in 2005 when I upgraded everything else to poly.

quote Originally posted by rogergarrison: Id say it has to be an inline engine and transaxle. FWD style just dont have the beef for big block stuff. Mid 60s Mopars put out over 700 hp stock from showrooms (425 valve cover decals were a joke) and their 4 spds and automatics were still nearly bulletproof. With inline, you can go with ZF trans. I may be wrong since I dont follow drags much, but I cant remember ever seeing or hearing of any funny cars or rails that tried a transverse setup. If you want it to stay looking Fiero, build your own tube frame with the correct wheelbase and just use the body panels. I think one member here does have an inline 455 Pontiac, but dont know his trans setup. My V8 Fiero originally had a 383 stroker with just around 400 hp. I couldnt get pro built TH125 to last more than 1,000 miles on the street...never went to the track. We tried all kinds of TCs, stainless, fiber bands, high pressure pumps and valve body, and as many as an 8 disc clutch pak. I went thru 3 in less than a year, swapped in a stock ZZ4 small block and still blew tranny up in 1,000 miles. I did break a couple of CV joints and axles along the way also. I got so pizzed in the end I sold the $20,000 car for $5000 at a classic sale. If I remember, Tina blows apart about 2 transmissions a season.

WOW!! That is insane. So now I'm sure i will be going with a different engine/tranny setup.

Whoa!! A BUILT 125 couldn't take the power? That thing must have been a monster!

quote Originally posted by Jncomutt: Whoa!! A BUILT 125 couldn't take the power? That thing must have been a monster!

He did say it was a 383--Them things gots MOSTER POWA!!!!

SST....

Although it is custom, the basic principal applies. You may get some ideas from my CarDomain page in my signature. The setup I have (645 crank hp conservate) will handle the power. A trans cooler would be needed for long track days with hard runs. But for a street application it should be fine.

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Paul

My IMSA Build: http://www.cardomain.com/ride/789315
HHP Adjustable Sway Bars: https://www.fiero.nl/forum/Forum4/HTML/036556.html

R Runner,
Thanks for that link. After reading it I realize the planning involved in the design and construction of a vehicle can be difficult at times but in the end very rewarding. I'm only in the design phase of my project I hope the excitement stays with me thru out this build. I now need to get my garage built.

No, they did not put out 700 hp in the mid 60's.

[This message has been edited by weaselbeak (edited 03-21-2009).]

quote Originally posted by SST: R Runner, Thanks for that link. After reading it I realize the planning involved in the design and construction of a vehicle can be difficult at times but in the end very rewarding. I'm only in the design phase of my project I hope the excitement stays with me thru out this build. I now need to get my garage built.

That is exactly the way I started. I build a shop first with plans to build a car. It makes life SOOOO much easier. The will be plenty fo challenges with the car. The last thing you need is tool challenges. Building a car is kind'a like riding your bicycle across the country... Make a big plan, divide it into stages then take it one day at a time and only focus on accomplishing what needs to be done that day. Building a car is overwhelming.... mounting a tank, wiring a gage or some other small task is easy. Stick with it and it WILL be come a reality.

check out www.zzperformance.com, they sell beefed up 4t65E trannys that could handle the power.

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Fiero w/ 1998 Supercharged 3.8 V-6 Intercooled
Best ET: 12.20@ 114.90 mph (street tires)
11.74@115 mph (drag radials)

"NO Juice....Just BOOST!"