yo my car was a stock 81mm b16 10 to 1 compression and on 7 psi i almost made 300 whp and my car would have lasted forever but bein that i had the boost controler and put it in and decided to just run around with it in on like 20 psi and did a dumb ass highway pull 4th gear and spun 2 bearings but the pistons and walls where still like new but its up to you what you want to rock 7, 15, 25, 30 just be smart and remember that anything over 300 whp in a light ass car is crazy and you have to know how to drive it