compensating for larger injectors via fuel pressure?

[fiveSFE]

i have a set of 780cc injectors on my car, i found the car way easier to tune when i had my 550's on the car, the problem was they were almost maxed out with my 50 trim.

I was reading that lowering the fuel pressure would in theory make my injectors act like they are smaller.

does anyone have a formula for this, i am running stock 38 psi fuel pressure right now. how much would i have to turn the fuel pressure down to make my injetors act more like...650cc's?

edit: i dont have the money to go out and get an eprom and tmo with injector compensation, so that is not an option right now.

 

[Talesin]

Flaw in the theory. Ever use a garden hose? Set the end to spray at a fine mist? Notice how it doesn't spray right (or the same) if you turn the water pressure down... kinda turns into a dribble, doesn't it.

Same thing with those larger injectors. The fuel needs to be at a certain pressure to mix with the air for proper combustion. Which is why the injector pulse width needs to be altered instead. Which is (in effect) what piggybacks and (more directly) replacement EPROMs do to compensate for the increased injector size.

Short version, no. Turning down the fuel pressure won't help, and will make it run worse. You *could* turn up the pressure a bit on the 550s, if you still have them.