flaatr Posted July 29, 2010 Report Share Posted July 29, 2010 It is my understanding that the stock boost level on a stock G54B StarQuest was around 8 PSI... I've been talking to a local guy who claims his car boost 12 PSI and it's all original i.e. no aftermarket boost controller, fish tank valve, etc. Is he full of 'stuff' or am I mistaken? -Raffi Link to comment Share on other sites More sharing options...
starquestG54B Posted July 29, 2010 Report Share Posted July 29, 2010 ive had my orig 12A hit an astounding 17psi with a manual boost controller "NOT RECOMENDED' since then i backed it down to around 12. 12psi is the safest psi for these turbos . if you want more boost get a bigger turbo! Link to comment Share on other sites More sharing options...
starquestG54B Posted July 29, 2010 Report Share Posted July 29, 2010 different years offered different boost levels to allways stay ahead of porsche and the nissans back when these were new. 87-88-89 i believe were orig 12-13 psi from the factory Link to comment Share on other sites More sharing options...
BC_99 Posted July 29, 2010 Report Share Posted July 29, 2010 stock should be 7-8 psi but you really need an aftermarket boost guage to know accurately. I have heard of changing some vac lines around on the stock 3 port wastegate to attain more, but have never tried it. The stockboost guage is just the ecu's educated guess. I can attest to removing the stock very restrictive exhaust and running a 2.5 turbo back setup helping boost, it has me peeking at 10 psi and creeping back to 8 psi on a 89 shp with stock 12a. BC_99 Link to comment Share on other sites More sharing options...
TexasQuest Posted July 30, 2010 Report Share Posted July 30, 2010 83-87 cars were 8 psi stock 88-89 cars were 10 psi stock Link to comment Share on other sites More sharing options...
StrongTyer Posted July 30, 2010 Report Share Posted July 30, 2010 83-87 cars were 8 psi stock 88-89 cars were 10 psi stock That sounds right. Ive always heard 7 1/2 psi on stock boost but I know for the 88's and 89's the boost was raised to about 10psi (sounds about right). My stock gauge on my STOCK 89 reads about 10-12psi at full boost. Still I wouldnt trust the stock gauge at all. Link to comment Share on other sites More sharing options...
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