Is there someone who custom turbocharged L98 vette?
I thinking about turbocharging my vette,
Cause it is v8 there should be two turbos
That will be lubricated from independent oil system (I do not want more heat stress and oil pressure drop in engine)
external oil pump – say in AIR pump place, external oil reservoir and oil radiator cooler (all amount of oil in that system: about 3-4 liters)
Turbo (turbos) will be water cooled from normal engine cooling system too.
Intercoolers will be placed in front of car where now in passenger side now is radiator reservoir (I relocated it one year ago) and on driver side is tank for gas fumes (I do not need it) and vacuum reservoir (I can relocate it)
All necessary pipes (intake and exhaust side) are no problem for me (stainless steel is cheap in Poland) intercoolers too, I can use intercoolers from audi 2.2 t ($10 cost used one, yes, ten dollars) or make custom ones.
Of course used turbos from some small engine.
My target is 50-100 HP more. (with more than 70 hp I will be happy)
And now questions:
1. how much boost can withstand without any problem STOCK L98?
2. Is there possibilities to make only one turbo (only one engine side?) (costs saving question of course)
3. Will it run with stock ECM program?

What do you thinking (bonus question)? :D

Jerry

 

I am not sure how into the Corvette world you are so this might seem like a stupid post. Reeves Callaway produced twin turbo corvettes for 4 years I think. Also John Lingenfelter is putting turbo's on the C5. Do a search here on the forum for threads about turbos because I have seen several threads posted about homemade setups.

 

http://www.meacham.pointclark.net/Home1.htm

This guy did a pretty good job.

 

I dont think it is worth doing unless you do it right.

Getting the parts are a no brainer.

You need to decide where you are going to mount them, where they fit, and how you will plum it from there.
You need custom made headers/manifolds for this.
How are you going to deal with the intense heat they create?
What are you going to do about tunning it? If you add more air, you need to get more fuel in there too. how will this be done? additional injectors?

You need to know if an audi turbo can put out enough air to not end up being a restriction to the L-98

Most guys put twin turbos on a vette for mainly 2 reasons.
1 they spool up a bit faster when they are 2 smaller units.
2 it is a lot easier to get the exhuast out on the 2 sides of the car instead of running a cross over pipe from one side of the engine to the other (ground clearence) where the turbo is mounted.

If you did run a single turbo mounted say, where the radiator was, then you need to get a 4" down pipe out of the engine compartment, which will not be easy inless you dump it on the ground in front of the engine without a muffler.

for the amount of power increase you want, I think the turbos are a waste of money and mostly your time + the headaches you will encounter.

Just shoot a 100 shot of N2O in the motor if you only want 70-100 more HP. Quick an easy.

If you just wants something different and cool, then go for it, just look around at what all these other guys with turbos are doing.


[Modified by bill mcdonald, 1:24 PM 7/11/2002]

 

The plumbing for a tt corvette is a nightmare, although it can be done, you could probably build a nice forged 383 with a supercharger for less cash.

 

I just thinking about light turbo setup, not monster. Only small boost. I saw somewhere that supercharger kit systems (vortech, paxton) for vette uses 6 psi boost (I am not sure that 6 psi) without modifying any internal engine components and I think (but could be wrong) they run on stock ecm program.
So, make only about 3-5 psi of boost from turbo setup?
Jerry

 

yeah 6 is generally safe amount of boost for a stock engine... I still dont like that idea but...

CFM of those turbos is what matters.

 

If you are going to use the Callaway twin turbo setup as a guide for a turbo charging system on your own car, you will have a few problems. Some are avoidable, but others are not.

First, Callaway mounted two RotoMaster turbos low on the side of the engine. This made it easier to feed oil to them and simplified the exhaust manifold design. But the problem this presented was that the passenger side frame rail had to be modified for clearance, and the front crossmember had to be used as a airbox (because it sat just ahead of the turbo charger's intake. You can avoid this setup if you mount the turbos elswhere - say just behind the radiator above the crossmember, but the exhaust manifold design becomes much more complex.

Secondly, Callaway used a secondary fuel injection computer (called the Microfueler) and 2 additional fuel injectors. This was needed on his earlier cars 'cause the L98 engine used a Mass Air Flow sensor. When GM switched to a MAP sensor on the L98 (1990 and 1991) Callaway moved away from the Microfueler and instead installed modified E-PROMs which were programmed to compensate for the additional airflow. If you are running a MAF sensor on your car, then you'll need to consider using a secondary fuel system (or much larger injectors). If you are running a MAP sensor, then a modified E-PROM will probably suffice (depending on the amount of boost).

Thirdly, the components that Callaway installed in his twin turbo charged powerplants where pure race-bred parts. The bottom end of his engines were nowhere near stock! With that said, his twin turbo setup only produced only about 8 or 9lbs or boost on a motor with an 8.5:1 compression ratio. With a stock bottom end, I wouldn't suggest anything higher than 5lbs.

In all honesty, you would be much better off spending the money on a supercharger kit. Either a ProCharger or a Paxton kit will provide you with the performance you are looking for, and it's already engineered to fit - no guesswork. And if you really wanted to do it right, get a partial ZZ4 engine from GM and use your stock cam, heads, TPI, distributor, and exhaust manifolds along with the supercharger kit, and you're set.

Good luck with what you decide to do.

 

If 70 hp is all you're looking for, I'd recommend going the 'all motor' route. The costs will be similar, but you'll end up with a much more liveable motor. With the turbos, you're going to need to deal with a LOT of plumbing. That plumbing gets in the way of working on the motor (see Callaway Twin Turbo for a good example). Second, Turbos make HEAT. That heat is really hard on the REST of the car.

If you've got any kind of mileage on that motor, it won't live very long under boost. IF the boost is low enough to not hurt the motor, you're throwing away your money in potential power output.

Here's an example (erm. Mine) YMMV and you can certainly go cheaper than this: I had a local Vette shop quote $6800 for an out the door supercharger install on my 120000 mile L98 mill. THEY said it'd be fine if the motor tested okay on the leakdown test. (I disagreed and beat feet out of there!)

I've got about $9000 in the system that just turned an adjusted 12.5 @ 115mph. (475+ hp at the crank) It's a new motor, it make tremendous torque, is well programmed, well behaved, and would take a 250hp shot of squeeze and live (everything SOUTH of it wouldn't though.) The additional work makes it a BULLETPROOF motor.

Do a search on Scorp's build up. He spent roughly a third of what I did and built a GREAT motor with it. You can too.

p.s. Factor programming. the Stock ECU will NOT like any major mods you do.


[Modified by RocketSled, 4:47 PM 7/11/2002]

 

thanks
it start looking complex. :crazy:
Start understand why so rare turbo setup for vette is.
Jerry