fc3sturboII

hi i was wondering how much a stock 88 s4 turbo II boost? i heard that it boost 6.5psi and i have heard of 8.5psi. so which one is it? mine is boosting at 9psi. so i wanted to know how much over boost its doing. thanks

J-Rat

iTrader: (2)

I think the stock level is somewhere in the 5.4 PSI range, with fuel cut coming in around 8 PSI (7.xx). At 9 PSI, your overboosting, but not too badly.

fc3sturboII

well i do have upgraded fuel pump fuel injectors and an afc. its just i get so many different answers to how much stock boost is now its 5.4psi. the fuel cut off is at 8.6psi i know that. but i still want to have a for sure answer on the stock boost.

Rx-7Addict

iTrader: (2)

I think its 6.5 lbs

NZConvertible

As per the FSM, stock max boost for the S4 is 6.6psi, but it doesn't hold that to redline. Most stock S4's now have clogged cats and worn turbos, so they may not get that high anymore. However most S4's aren't stock.

eriksseven

iTrader: (6)

my stock s4 cuts out at around 7.5ish... Although this is only on very cold nights.

fc3sguy

bout how much boost can be expected from and S4 with full 3" exhaust? Or should I say how much boost creep?

fc3sturboII

cool thanks 6.6psi sounds about right

J-Rat

iTrader: (2)

Thanks NZ... I had my figures crossed...

$150FC

port the wastegate and you won't have any problems controlling it. WKZ(Works)'s car had full 3" and intake, and after we ported the wastegate it went back to nearly-stock levels, like ~6 psi.

before the porting it would hit ~11.5psi.

RX7withNitrous

one question fc with an f-150 bodykit???

fc3sguy

$150FC, is close to 12psi a reall danger zone for an engine. I have some fuel upgrades, set of new 550's in primary and 720 in secondary, walbro pump and fuel pump rewire mod. If yes, how hard is it to port a wastegate? Did you do it yourself? What kind of tools would you recommend?

fstrnyou

i heard you have to beat the housing off before porting. ewww. i don't want to have to do that.

Sergei The Saint

I have just ported my turbo, it was easy, I took it to NAPA workshop and the guy did it for $9.95, the rest was just me constantly taking the turbo off and putting it back on (that turbo cover is a bitch!!, so I just left it off, i'm guessing that will heat up my engine, but after I modded my cooling my engine is running very very cool) Anyways, I have the FCD and I have the 3" full exhaust from Racing Beat, my question is, you said "port the wastegate and you won't have any problems controlling it. WKZ(Works)'s car had full 3" and intake, and after we ported the wastegate it went back to nearly-stock levels, like ~6 psi.

before the porting it would hit ~11.5psi. "

Do you mean the performance is only there when the turbo isnt ported? I've been reading everywere that it give around 10-11 psi of boost, is this wrong?
I"m interested as to what my performance boost is gonna be? (I dont have the car done yet, as to how I found a leaking pulastion damper, so waiting to fix that first, wouldnt want any fires now)