Day Dreaming : Grassroots Supercar

Porsche 930 behind SBC in a Corvair.

I'm a- likin' 930 boxes for swaps like this, but they seem to be priced from $4k up. Not so grassrooty.

If you would consider transverse and you are comfortable with GM V8 stuff, take a look at the LS4 like Wally said:

http://en.wikipedia.org/wiki/GM_LS_engine#LS4

It comes attached to the 4T65 auto that could handle your magic 600 hp number with some basic automagic mods. The same auto is attached to the 3.8 SC engine, which could also get to the power numbers you want, but starts with a displacement disadvantage compared to the 5.3 LS4. The 4T65 is what the Ecotec drag racers use in 1000+ hp applications. I know you said manual, but if budget is the key then using an auto makes your budget much lower. Here's a build book on the mods done with the 4T65 to hold up in the high hp drag cars...gotta love the open book from GM!

http://tunersource.gmblogs.com/Racer-Tech/gm-sport-compact-performance-build-book/104742-enginehandbook_04racemodtrans.pdf

Obviously, since they give descriptions on how to make one of those hold up to 1000+ hp in drag racing, not all of it would apply to a 600 hp street car, but you get the idea.

Bryce

I've watched the 4T65 developement for a while and that was the"second" choice. Second, because it is automatic. The costs is right. I threw the manual idea out there in hopes that it could happen.

Info on the Audi/Porsche transaxles as used in GT40/Lamborghini replicas, SBC powered 944's, etc.

http://www.gt40s.com/forum/how-engines-transaxles/23996-g31-transaxles-audi-016-083-transaxles-pete-tinucci.html

http://www.lambolounge.com/Chassis/Transmission/Audi-915/index.asp

http://www.lambolounge.com/Chassis/Transmission/5000/5000.asp

http://www.porschehybrids.com/php/viewtopic.php?f=5&t=2018&start=0

http://www.porschehybrids.com/php/viewtopic.php?f=2&t=771&p=5056&hilit=Power+limit#p5056

Of course the Audi V-8 powered Lotus Esprit project:

http://www.motorgeek.com/phpBB2/viewtopic.php?t=9648&postdays=0&postorder=asc&start=0

It seems as though an engine that makes power higher in the RPM range may not abuse the components too badly as it is the torque that tends to kill the parts. Of course not doing clutch dumps helps a lot. Seems that a number of the makers of "real" supercars use the clutches as fuses to help the transmissions survive, the rest of us just buy used transaxles from the yard

The fact is that a lightweight beetle based fiberglass car will be potentially very light and with 300hp you'd have supercar potential. 600hp would likely be enough to take on the Veyron, which is more of a hypercar than a supercar.

Does the Northstar idea interest you? Might know someone who can help.

I really like the SBC/ porsche 930 tranny combo pictured in the Corvair pic above for you.

It might not handle the 600 ponies, but it could get close. Engineering would be clean, you can build the motor cheap, spend a little extra on the tranny and you may have it.

Supercar, huh? You gonna include all the goodies like traction assist, pushbutton auto/manual switch on the dash, drive by wire, navigation system, and leather bun warmers?

i have had an idea for a while that involves my 2009 challenge car. it involes putting an secret into the middle of a secret and connecting a secret at the front by means of chain drive. think fords group b effort, only with a gsx-r powertrain.

SVreX wrote: Supercar, huh? You gonna include all the goodies like traction assist, pushbutton auto/manual switch on the dash, drive by wire, navigation system, and leather bun warmers?

No, just something that if you saw it go by on the othe side of the highway, you would turn your head and think "Wow, that Dude has money!." Low, fast and handles, that all. I enjoy the brain storming. And, I don't want to miss an option because I did not ask. However, the leading choice is a 4G63 E&T with a C-4 front.

I think the T56 transaxle is probably your best bet. They were installed behind Ford, GM, and Chrysler stuff, so a quick swap of the front plate and input shaft and you can bolt one on behind a viper V10 if you want.

Don't worry as much about the HP rating as the TQ rating. A T56 will handle 1000 hp, as long as you don't exceed about 550 tq on 94+ models. They're given a 100k mile warranty in the Viper, so they must be able to take some abuse. 92 and 93 models have less desirable ratios and lower torque handling; more like 350 lb-ft. You will have to mix 'n' match a couple parts for an SBC. Use a bellhousing and input shaft from an LT1. The LS1 bellhousings and input shafts are a bit shorter and you'll have a little more difficulty with clutch things. Going to the LT1 bellhousing and input shaft will allow you to bolt it up to an SBC like it was supposed to be there using off the shelf parts.

I think the T56 transaxle is probably your best bet. They were installed behind Ford, GM, and Chrysler stuff, so a quick swap of the front plate and input shaft and you can bolt one on behind a viper V10 if you want.

Don't worry as much about the HP rating as the TQ rating. A T56 will handle 1000 hp, as long as you don't exceed about 550 tq on 94+ models. They're given a 100k mile warranty in the Viper, so they must be able to take some abuse. 92 and 93 models have less desirable ratios and lower torque handling; more like 350 lb-ft. You will have to mix 'n' match a couple parts for an SBC. Use a bellhousing and input shaft from an LT1. The LS1 bellhousings and input shafts are a bit shorter and you'll have a little more difficulty with clutch things. Going to the LT1 bellhousing and input shaft will allow you to bolt it up to an SBC like it was supposed to be there using off the shelf parts.

fiat22turbo wrote: Info on the Audi/Porsche transaxles as used in GT40/Lamborghini replicas, SBC powered 944's, etc. http://www.gt40s.com/forum/how-engines-transaxles/23996-g31-transaxles-audi-016-083-transaxles-pete-tinucci.html http://www.lambolounge.com/Chassis/Transmission/Audi-915/index.asp http://www.lambolounge.com/Chassis/Transmission/5000/5000.asp http://www.porschehybrids.com/php/viewtopic.php?f=5&t=2018&start=0 http://www.porschehybrids.com/php/viewtopic.php?f=2&t=771&p=5056&hilit=Power+limit#p5056 Of course the Audi V-8 powered Lotus Esprit project: http://www.motorgeek.com/phpBB2/viewtopic.php?t=9648&postdays=0&postorder=asc&start=0 It seems as though an engine that makes power higher in the RPM range may not abuse the components too badly as it is the torque that tends to kill the parts. Of course not doing clutch dumps helps a lot. Seems that a number of the makers of "real" supercars use the clutches as fuses to help the transmissions survive, the rest of us just buy used transaxles from the yard The fact is that a lightweight beetle based fiberglass car will be potentially very light and with 300hp you'd have supercar potential. 600hp would likely be enough to take on the Veyron, which is more of a hypercar than a supercar.

Wasted a lot of time on the v8 esprit thread. I always forget how much work goes into projects like these. That seems lilke a very straight forward swap and it fit quite nicely, but there was a lot of custom fabricating involved. Lots of little details.

curtis73 wrote: I think the T56 transaxle is probably your best bet. They were installed behind Ford, GM, and Chrysler stuff, so a quick swap of the front plate and input shaft and you can bolt one on behind a viper V10 if you want. Don't worry as much about the HP rating as the TQ rating. A T56 will handle 1000 hp, as long as you don't exceed about 550 tq on 94+ models. They're given a 100k mile warranty in the Viper, so they must be able to take some abuse. 92 and 93 models have less desirable ratios and lower torque handling; more like 350 lb-ft. You will have to mix 'n' match a couple parts for an SBC. Use a bellhousing and input shaft from an LT1. The LS1 bellhousings and input shafts are a bit shorter and you'll have a little more difficulty with clutch things. Going to the LT1 bellhousing and input shaft will allow you to bolt it up to an SBC like it was supposed to be there using off the shelf parts.

The problem with that is he wants it to be mid engined. If you had a SBC tied to a T56 tied to a differential, the engine would have to be in the passenger seat.

16vCorey wrote:

curtis73 wrote: I think the T56 transaxle is probably your best bet. They were installed behind Ford, GM, and Chrysler stuff, so a quick swap of the front plate and input shaft and you can bolt one on behind a viper V10 if you want. Don't worry as much about the HP rating as the TQ rating. A T56 will handle 1000 hp, as long as you don't exceed about 550 tq on 94+ models. They're given a 100k mile warranty in the Viper, so they must be able to take some abuse. 92 and 93 models have less desirable ratios and lower torque handling; more like 350 lb-ft. You will have to mix 'n' match a couple parts for an SBC. Use a bellhousing and input shaft from an LT1. The LS1 bellhousings and input shafts are a bit shorter and you'll have a little more difficulty with clutch things. Going to the LT1 bellhousing and input shaft will allow you to bolt it up to an SBC like it was supposed to be there using off the shelf parts.

The problem with that is he wants it to be mid engined. If you had a SBC tied to a T56 tied to a differential, the engine would have to be in the passenger seat.

In a car with the wheelbase of an original Beetle.

Force fed Northstar.

John Brown wrote:

16vCorey wrote:

curtis73 wrote: I think the T56 transaxle is probably your best bet. They were installed behind Ford, GM, and Chrysler stuff, so a quick swap of the front plate and input shaft and you can bolt one on behind a viper V10 if you want. Don't worry as much about the HP rating as the TQ rating. A T56 will handle 1000 hp, as long as you don't exceed about 550 tq on 94+ models. They're given a 100k mile warranty in the Viper, so they must be able to take some abuse. 92 and 93 models have less desirable ratios and lower torque handling; more like 350 lb-ft. You will have to mix 'n' match a couple parts for an SBC. Use a bellhousing and input shaft from an LT1. The LS1 bellhousings and input shafts are a bit shorter and you'll have a little more difficulty with clutch things. Going to the LT1 bellhousing and input shaft will allow you to bolt it up to an SBC like it was supposed to be there using off the shelf parts.

The problem with that is he wants it to be mid engined. If you had a SBC tied to a T56 tied to a differential, the engine would have to be in the passenger seat.

In a car with the wheelbase of an original Beetle. Force fed Northstar.

Why do you guys keep going on about the Northstar? I'm a huge fan, but I will admit that it's a heck of a lot easier and cheaper to make big power with a SBC, and the Northstar is a big honkin' engine due to the heads. The weight of the Northstar isn't bad compared to the SBC (despite it's increased size) but the LSx engines have all the benefits of easy/cheap power AND reduced weight AND reduced size. So why not use an LS4 + 4T65 instead of a Northstar + 4T80/4T80? To boost the N* to that power level you're going to need at the very least cams, pistons, valve springs, and timeserts...that stuff adds up in price quick.

Bryce

Or just boost the E36 M3 out of a 4G63, like Andy's considering. Lighter than all of the above options, cheap, and can make a butt load of power for little to nothing.

Nashco wrote: Why do you guys keep going on about the Northstar?

A beautifully designed engine (from an engineering perspective), V-8, 300 HP for starters (who knows what Wheels could do with one!), and transversely mounted, which lends itself to a mid engine RWD (if you can find a tranny).

But, I agree with you, probably not the motor for this.

Why won't 4WD truck stuff work, only using just the front output of the transfer case? Then use one of the Dodge or Chevy front IRS axle-ettes with the CV joint axle shafts on either end. It might not be the lightest weight option out there, but you could always pull the reduction gears out of the transfer case and such to lighten it up.

Curtis 73 where do you find this T56 transaxle of which you speak? The only one I can google is out of the Vette.

From Hemmings "The 1997-2004 Corvette also used aT-56, but this unit is mounted directly onto the rear differential as part of a transaxle, and not suitable for conversion to other vehicles."

This is the only mention of a transaxle I can find.

Everyone does say this is an expensive transmission tho.

i remember now that this "super car" idea has been done. allow me to reintroduce to you the www.durocco.com

the durroco rules!