I'm collecting parts to blow my 85 SE. I want to build a 6 port setup like TT just finished. Is the S4 engine stronger than the S3 for say 8psi? I have an S5 turbo and intake. Turbo engines do not turn up around here to often.

 

for 8psi it doesn't matter much which one you run, so i'd use the one in better condition

 

I'm using GSLSE 6 port irons. I don't think the intake ports changed on the 6 ports through the years. I'm not sure though. The only reason I reused the GSLSE 6 port irons was cause they were in great condition still and I couldn't find good 2nd gen NA irons.

Plus, having the coolant grooves in the aluminum housings is better than in the irons like 86 and after engines(except the renesis). For 8psi youll be fine with either like said above.

 

TT your running 8 right now, how much higher might you push your current build?

 

Just becuase I don't want to be at the power level where everything starts breaking the most i'll go is 12psi. If I went to 14 or higher I woud definitely do aux injection. Then I would need another fuel pump inline to push that fuel or bigger fuel pump.

I'm using high compression rotors(9.4 compression S4 NA).