What is the normal fuel pressure on a supercharged .. GT?.. im somewhere between 20 and 25.. my stang has od ball fuel rails..-- lightning fuel rails..
The computer measures the pressure across the injector. That target pressure is like 40 psi. So, if you have 15 psi of vacuum in the intake, the actual pressure in the rail is only 25. If you are NA, when you go wide open, the is no vacuum and no pressure in the intake so the computer will command 40 psi. If you have boost, the intake will be pressurized and the computer will command more pressure so that the pressure coming out of the injector is 40 psi relative to what is in the manifold hence adding 1 psi fuel pressure per lb of boost.