1990 Turbo Grand Prix?

[Tweeter]

Ok, I have a question about these cars.

Would the turbo set up off of one of these cars work on ours.
I mean the manifold and turbo?

The reason I am asking is this last weekend I found out that my wifes uncle did alot of the work on these cars and he might know where I can get a Turbo and Intercool for one of these cars brand new in the box. And I thought that if the Manifold would work I would get on for my car and set it up.

Any info you may have on this let me know.

Thank you

[Sexysteve]

hey chad, isn't the 90 prix a 3.1? at least i think it is

[Craig99SE2]

Yes, the TGP is a 3.1.

The intake manifolds are totally different. The turbo is WAY undersized! As are most factory turbos. For anyone considering a turbo, I would HIGHLY suggest you look at an aftermarket turbo. 95% of factory turbos are undersized on purpose in order to reduce lag. Being too small, they spool up VERY quick and provide a consistent power band thus increasing driveability. But the trade-off is that you don't take advantage of the turbo's potential to make power. That is why people can swap in a larger turbo in a factory turbo car and see significant power gains!

Probably the closest matched turbo to what the 3.4L SFI requires as far as CFM's are concerned is the stock Buick GN turbo which is a hybrid Garrett T4(0B?). I still have yet to find any compressor info, but the turbine was available in either .63 or .82 A/R. Both will work for our cars. .63 will spool up quicker, whereas the .82 will have more lag, but provide more top-end performance.

For more info on turbos and flow, check my site at: http://www.jeepnuts.com/12sGASE and I would STRONGLY recommend picking up a copy of "Maximum Boost" by Corky Bell.

[Tweeter]

Well I read on this Turbo and .82 A/R. It is a Garett 2.5.

[Craig99SE2]

Originally posted by Tweeter
Well I read on this Turbo and .82 A/R. It is a Garett 2.5.

It is a Garrett T25 which is WAY too small for the 3.4L. It is borderline on the 2.4L. I'd still suggest AT LEAST a T3 on the 2.4L. and T4 on the 3.4L. As far as turbine A/R, it depends on what you are looking for! If you want mid-range power, get the .63, if you want top-end (i.e. 1/4-mile) go .82 ... YMMV

[SpyhunteR]

borderline for a 2.4? man that turbo would fall flat on its face halfway through the rev range on a 2.4L... small T3's have trouble enough...

T3 or better man.. T3 or better

[Craig99SE2]

Originally posted by SpyhunteR
borderline for a 2.4? man that turbo would fall flat on its face halfway through the rev range on a 2.4L... small T3's have trouble enough...

T3 or better man.. T3 or better

That's why I said AT LEAST a T3! :boogie:

[Tweeter]

Well you are right it is a T-25 and here are the numbers on it below.

Garret T-25 turbo .80 A/R intake , .62 A/R exhaust w/ closed loop boost control and integrated waste gate.

I was thinking it might be a good way to get a turbo on a 3.4L motor with out alot of money. As for the Manifold I was taking about the Exchaust, is it the same set up as ours to make it easy to mount the turbo?

I just miss My Omni with it 2.2L motor with a T-1 Putting out 10 PSI. The guy I sold the car to put a 2.5L motor in it and Did some head work and put is a new Computer and was running 15 PSI Running 13.5 on street tires.

[Craig99SE2]

Originally posted by Tweeter
Well you are right it is a T-25 and here are the numbers on it below.

Garret T-25 turbo .80 A/R intake , .62 A/R exhaust w/ closed loop boost control and integrated waste gate.

I was thinking it might be a good way to get a turbo on a 3.4L motor with out alot of money. As for the Manifold I was taking about the Exchaust, is it the same set up as ours to make it easy to mount the turbo?

I just miss My Omni with it 2.2L motor with a T-1 Putting out 10 PSI. The guy I sold the car to put a 2.5L motor in it and Did some head work and put is a new Computer and was running 15 PSI Running 13.5 on street tires.

You might get away with the exhaust manifold! I was going to use the 3100 rear manifold because it is a log-style versus the 3400 for my custom turbo. But decided to go custom tube headers instead.

As for the turbo, I would seriously consider something else! A Buick Grand National turbo would be more closely matched to our engines. You can grab those pretty cheap since GN owners are always upgrading. Since it is a T3 turbine (on the GN), it *MIGHT* bolt up to the T-25 manifold of the 3.1L. If not, I'm sure someone makes an adapter because I'm sure many TGP owners stepped up to the T3 at some point.

Good luck with the project.

[Tweeter]

Thanks for all the info. Once I get a few things taken care of I might try to get the manifolds off of a TGP. And start playing with things.

Good luck on your Turbo Also.

[Craig99SE2]

BTW, for the manifolds, check out http://www.car-parts.com

I've have GREAT success finding stocker turbo parts via this site. Saves calling all the local boneyards.