What is the maximum boost the stock s4 turbo can produce effieciently? If i were to mount a starion IC in the front how much boost would it create then?



Thanks again

10 psi

mine wouldn't really boost a lot more than that anyways



mike

my TII would hit 15-16 psi....... goddamn that thing was fast for two days https://www.nopistons.com/forums/pub...#>/BURNOUT.gif

anything over 12, and your over spinning the turbo. Its just not meant to flow that much air.

the turbo that hit 15psi had a garret T04 frontside on it.... it was quite happy spinning that fast. a stock turbo will start puking oil shortly after running it at high boost....

yeah my hybrid would happily boost to 15psi, the stocker had a hard time with 11-12 though



mike

My 6 port with Starion intercooler up front and S5 stock turbo assembly would peak at 12 - 12.5 psi at about 5000 rpms then drop back to about 8 psi by 8000rpms. The intercooler definitely worked - you could feel a huge difference in the piping after a hard run.



Jason

The stock s4 turbo will not go much past 10 easily unless you do some wastegate porting and such. the s5s work a lil better and puke oil at 14psi..13psi can be done, but not for long..12 is the most I would do.