Camaroz29

iTrader: (3)

Since GM fuel injectors are rated at the stock pressure setting (43.5 PSI) if you increase fuel pressure (to 51 PSI for example) do you just calculate what your injectors would flow at that pressure (like taking a 32 lb/hr injector and calculating that at 51 PSI it would flow 35.1 PSI) and enter that for your fuel injector constant in the PROM? People are always telling me that increasing the fuel pressure won't do much since the computer won't compensate, but I'm sure this is the way it is done.

Grumpy

The math is: you take the square root, of the product of the squares of the new pressure over the old...



Just to use some easy numbers, say you had 4 PSI and was changing to 5 PSI, the correction would be, 25/16s or 1 9/16. If the injector was a 20 PPH injector then at the new pressure it would be, 20x 1 9/16.

Find some other people to listen to. Things can be awfully easy, when dealing with the uninformed. The *problem* with changing fuel pressure is that it changes more then just flow, and some codes operate differently as far as learned corrections. Changing the pressure in addition to changing the flow changes the amount of atomization, and where the majority of fuel *lands* on the runner floor. These lil side effects can drastically change the *tune*.

Camaroz29

iTrader: (3)

I figured it would also alter the A/F ratio among other things. I just wanted to be sure that I was right about using fuel pressure to "increase fuel injector size". I ordered the racetronix 32 lb/hr injectors and they should be fine, I'm hoping to make 400-425rwhp with my next setup. But on the off chance I make more than that, I just wanted to make sure that upping the pressure would be like squeezing a bit more out of your current injectors. I could have gotten the 38s or 37s but they both cost about 40$ more and would more than likely be MAJOR overkill. Hell these will more than likely be overkill but I just want to be sure.