with an after market FMIC, meth, catless TBE, intake, hks 264s, AEM EMS, 9.8 hotside, I/C piping, 880cc injectors, boost controller, walbro, and a sh!tty exhaust manifold i was pushing 32psi on the stock turbo on 93oct. i believe i put down 353hp and 336tq on a mustang with that...of course during this i had blow by in #3 and between 1 and 2 the head was corroded away by combustion...nasty pictures...i never posted much with my car, but that blow by pic is in drivetrain and turbo threads somewhere.

i wouldnt suggest more than 26-27psi with those mods though. with your front mount...you can push a million PSI, but it wont be efficient at all. so efficently id put it at most 20psi...i really cant say because i did a front mount early. spend $500 and get a decently efficent intercooler, just let your car and turbo do what it wants to and breath. just my .02

 

my sig is a safe tune, but now im running 25 psi
spike in 3rd gear with 100 oct. On my tune. I don't recommend this, but I want to see about what the power ill get from the alky kit Im waiting for.

 

Dude THATS INSANE boost with the stock turbo. Without the meth 23-24 is ok with 93 octane IF you have the right tune. Good for you though

 

holding 24 psi

 

22-23 psi.

 

i used to run 25 psi when i was stock turbo
now i run 25-28

 

23psi on 92oct for a year and a half and still crossing my fingers. That is on the STI btw