Hi all. I went to a local dyno day today. My S14 w/ S13 blacktop SR made 223whp and 216ft/lbs tq at stock boost with the T2Small. Mods I have are Microtech ltx-8, Street Imports FMIC (the cheap ones on Ebay), 2.5 inch downpipe, 3 inch testpipe/exhaust and Z32 TT fuel pump.

But I need more power! (don't we all?) How much more hp do you think I can get outta the T25? From searching, most people say this turbo is only efficient up to about 14psi or 240whp. Does a turbo's efficiency depend on psi or hp? If I turn up the boost to 14psi and make over 240whp does this mean the turbo is out of it's efficiency range and blowing in hot air? Or will it be ok as long as I don't run more than 14psi and have enough fuel (get larger injectors)?

Thanks.

T25 turbo's start blowing more hot air than usable air at 14 psi. However if you turn it up to 14 psi you will be reducing the life of the T25. The next step for you would probably be a larger turbo.

you said stock boost.. You can easily up to 10 or 12 psi on your setup. from that i would expect to see around 250 to the wheels. ANY increase in boostpressure will shorten the life of the tiny T2.. but if you are going to replace it one day anyway.. you should use it until it dies.

The max horsepower numbers stated on the turbos do not mean that that is the limit. You can modify your car to run at 400hp(just as an example) and still be using the same stock turbo it all depends on your tuning knowhow.

My suggestion is that you start looking into other areas of the car for now(If you haven't done that yet) Always remember, Power is useless if you can't control it.

What hp range are you looking to be in or your goal? Also how is the intercooler you got off ebay cause I got one from street imports to I just did not put it on yet.

injectors and a fuel management system will help ALOT, even with the small turbo. 550cc, and an S-AFCII should get you around 280-300, depending on how good u tune it. Right now i'm runing 12psi with a Greddy FMIC, walboro 255, nismo FPR, at around 240ish.