dont go over 3 psi than...to play it safe. basically you need to be more concerned w/ the stock fuel setup until you hit around 6-7 psi, then worry about the intercooler. to run more than 3-4 psi (which is probably going to be pushing the stock injectors still at that point) you're going to have to upgrade your injectors, possibly your fuel pump as well. running the larger injectors will require an afc hack, SMC hack, or some kind of standalone management system....