I have been reading that some guys are going with bigger than 42lb. injectors for high HP setups cause the 42s aren't keeping a safe margin of air/fuel at high RPM/boost. There is a way to make 42 lb. injectors flow like 60 lb/hr injectors. By turning up the fuel pressure. The formula is:
(Fn/Fo)= square root of (Pn/Po)
Fo = origional fuel injector flow rate
Fn = new fuel injector flow rate
Po = stock fuel pressure
Pn = new fuel pressure
So: if stock fuel pressure is 39 psi, then 80 psi of fuel pressure would make them flow 60 lb./hr.. 80 psi is probably too much and the injectors wouldn't have the right pattern. But with a 255lph forced induction pump, you could probably run 50 psi with good results. 50 psi would make for a 47.6 lb/hr flow rate.
If you have a tuner, or tunable chip, you can just program the new injector flow rate into your program and it should be right.
I know a guy who was running a fuel injected 302 on the stock 19lb/hr Mustang injectors and he was running low 11s in the quarter with no nitrous. He was running monstrous fuel pressure to make up for it and it took some tuning to get it right. Obviously it would be best if you want more injector flow to just get higher flow injectors, but there are options for those of us who can afford a set of big injectors.
(Fn/Fo)= square root of (Pn/Po)
Fo = origional fuel injector flow rate
Fn = new fuel injector flow rate
Po = stock fuel pressure
Pn = new fuel pressure
So: if stock fuel pressure is 39 psi, then 80 psi of fuel pressure would make them flow 60 lb./hr.. 80 psi is probably too much and the injectors wouldn't have the right pattern. But with a 255lph forced induction pump, you could probably run 50 psi with good results. 50 psi would make for a 47.6 lb/hr flow rate.
If you have a tuner, or tunable chip, you can just program the new injector flow rate into your program and it should be right.
I know a guy who was running a fuel injected 302 on the stock 19lb/hr Mustang injectors and he was running low 11s in the quarter with no nitrous. He was running monstrous fuel pressure to make up for it and it took some tuning to get it right. Obviously it would be best if you want more injector flow to just get higher flow injectors, but there are options for those of us who can afford a set of big injectors.