just turning up the fuel pressure can do more harm than good, the car has to be setup correctly in order to get the longest life out of your setup, and get the best performance. 400-500bhp can be eeked out of a stock sr20, but with incorrect tuning, even a mildly tuned 300bhp motor will blow. its in the tune and setup, not necessarily the choice of parts. you've probably caused far more harm than good, and in fact it'll be your own fault. you cant just bolt stuff on, on the advice of random people you talk to online, and expect everything to be fine. every car is different, thus someone elses settings (such as fuel pressure, for example) will not be the same as your car will require, especially if its running a random turbo. if its still running like crap after turning the boost down then i'd be inclined to whip the head off, see what state the internals are in.