I have 1991 twin turbo model . just a question but how would i know if both turbos are ok . i have fitted boost gauge . what boost should i get ???
ok so i have bit of a update.
been out today and been watching the “aftermarket boost gauge” that i fitted the boost gets to about 12-14 psi then drops away under heavy load . like pulling away from 50 kms in third gear and drops to about 6 or 7 psi . is this correct , or is there something i should check ?
Any help would be great
Well i must say i am a bit upset no one had any advise for me ?
I would help but I haven’t got the knowledge. It seems to be a boost leak or something. Might be worth checking all the air/vacuum connections. and making sure they are tight and not leaking at all.
Any strange noises?
Ok so my understanding of this is as such: the turbine spools and generates the boost - at lower revs you want the turbo to spool fast to minimise turbo lag. But as the engine rpm increases the pressure will drop as the compressor wheel itself becomes the resting force as well as the intercoolers and the pressure drops. Therefore I think what you’re seeing is normal. Another thing to check is if you have oil in the air intake Y pipe - a little mist is ok but if there is excess oil your turbo oil seals are failing.
ok cool stuff thanks for the info i will check y pipe connection out . i have fitted metal y pipe as my plastic one popped of the the seal got stuck in butter fly valve , sending engine to red line " only for 10 sec "
shut car of , limped home , then got me a metal one , with some good bolt type clamps. very scary moment. i will report back when i check “Y” pipe
Do you have a problem with the cars performance or are you just curious?
If either turbo is faulty you will normally have one of the following symptoms. Abnormal noise from turbo, smoke from exhaust, oil in pipes connected to the turbo or metal filings in pipes and engine.
Fitting the aftermarket gauge will not tell you if the turbo is faulty, only what the pressure is. You will then have to locate the cause of the fault which may not be the turbo itself.
well my car runs all ok i just curious if thats normal . there is no strange noises, or black smoke. its not using any oil . i allways thought that when the turbo spools up it would keep the boost pressure at one point using waste gate valve . but i dont know if that happens with GTO .
update , so i pulled of y pipe hoses , i was painting the bracket that holds the HT packs . did solid pipe right side of engine ( looking from front ) repainted black . any ways there was no oil in the Y pipe at all so looks like my turbos are all ok