Turbo question???????

[937DYTBOI 5,000+ posts]

hey im lookin to get this 87 buick grand national off this guy but the turbo only boost up to 9lbs he says. The engine is not stock i dont know if its another buick 3.8 fuel injected engine or some other engine and it has a bigger turbo than the stock one. I believe it has the original computer with a chip installed. I was thinking the problem may be just to uninstall the chip and see what it does or if the engine doesnt have the proper compression for the turbo itself, i really want the car but want to decifer what could cause this problem before i give this guy this money and be stuck in a a big hole to fix the car. If anybody has any info let me kno

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[pd298 10+ year member]

Wheres marley when you need him. He owns a GN. He will be able to help you with whatever you need..

 

[dalucifer 10+ year member]

what is the boost supposed to be at?

 

[937DYTBOI 5,000+ posts]

i actually PM him first but i guess hes not online but i was checkin to see if anyone else has any info

 

[937DYTBOI 5,000+ posts]

im not sure to tell u the truth im bout to do a google search

 

[phantom240 5,000+ posts]

9lbs sounds about right for most cars that come from the factory with a turbo.... :dunno:

 

[dalucifer 10+ year member]

9lbs sounds about right for most cars that come from the factory with a turbo.... :dunno:

thats what i was thinkin, but he said it was chipped.

 

[937DYTBOI 5,000+ posts]

But its a aftermarket turbo with bigger injectors i forgot to say.

 

[kuijo 10+ year member]

don't the wrx evo srt-4 all come with around 15psi stock? or closer to 1 bar

 

[Lunchbocks 10+ year member]

what type of boost control does the car have? manual, electronic, is there a control solenoid? gotta find that first, if its an electronically controlled unit (either aftermarket system or factory solenoid valves or something along those lines) then its possible that the aftermarket chip controls the operation of this unit and sets a limit to 9psi

also, determine if the turbo is externally or internally gated, because it could also be boost dependant solely on a interchangeable wastegate spring

 

[937DYTBOI 5,000+ posts]

ok i will check on the boost control. Sorry but im turbo illiterate but im going to learn i know the parts but not really on everything i know whats involved. Whats a good aftermarket intercooler?

 

[937DYTBOI 5,000+ posts]

Well this is what i found off a website on the 87's

Maximum boost was set at 15 psi and the turbo used an electric wastegate. The turbo also incorporated special low drag, dynamic turbine shaft seals, and a built in contamination trap.

 

[RandyJ 10+ year member]

Then the turbo he put on probably is internally gated at 9psi. But there are certain things you need to look into. You may not want to up the boost. A PR of 1.61 may be the in peak efficiency island with the turbo selected, as well as providing power is the desired band. Upping the boost may cause problems with flow. Try to find out what turbo it is and we can get you some maps and flow numbers.

And you need to knwoo what you're flowing before you go and buy an aftermarket IC,it would **** to end up losing 4PSI because you chose the wrong IC when you didn't know your numbers, ya know.

 

[pd298 10+ year member]

9psi is not that much. SRT-4 come from the factory pushing 13psi...

 

[RandyJ 10+ year member]

9psi is not that much. SRT-4 come from the factory pushing 13psi...

The turbo installed on this motor and the turbo on an SRT-4 may be very, very different.