Originally Posted by RolanTHUNDER

oh okay. Is your SC kit the AP1 kit?

Originally Posted by s2000Junky

Another thing you will need for 8psi aka 4" pulley on f20 if your running a kit that was designed for the ap1/F20, is a ap2 rrfpr (or a retrofit kit) to convert your existing unit. The ap2 rrfpr has a steeper ramp up rate of fuel delivery because the f22/smaller stock pulley needs more fuel per same rpm but with less rpm/rev limit. Running more boost beyond the 1-1.5psi im recommending (7psi max) will require more rising rate then what the ap1 unit will provide. This also means the fuel delivery/rising rate pressure will cap off/reach max pressure before you hit 9km rpm. Fortunately as luck would have it, on the stock ap1 ecu, it runs too rich from the factory from 8-9k rpms, so it actually works out ok with the net effect in proper fuel curve.