Try2pass

I have a LS3 in my '80 corvette. When dynoed they said at high RPM I wasn't getting enough fuel (I've always thought that on the top end when punched it didn't "go" like it should). I have a ACDelco P381 fuel pump that supposedly puts out 61 psi and 41gph. Are those the numbers the LS3 needs? Are there fuel pumps that put out the 61 psi with 50-60 gph that would fit my tank? Would that hurt anything? When I grow up I'd like to put a LS7 in there which probably calls for more gph? Any info. would be very helpful! Thanks.

LS1MCSS

iTrader: (18)

This should end your pain, as long the rest of the system is up to it.

http://www.summitracing.com/parts/ae...make/chevrolet

Try2pass

That pump puts out 90 psi and about 90 gph. Does that hurt anything as the LS3 calls for 60 and 40? Can that pump be tuned down some?

LS1MCSS

iTrader: (18)

The regulator will take care of that.

gagliano7

I had a 2008 vette and that ls3 was still pulling hard at redline. I would say you need to upgrade fuel pump

moeZ28

iTrader: (7)

What size injectors are you using? Is the car tuned?

Try2pass

I had the car dynoed and tuned and it was then that Tommy Wong said that at high RPMs the engine wasn't getting the fuel it needed.

I don't know the size of the injectors. Is that something that can be easily looked at? Do all fuel pump regulators have adjustable controls that we can set to regulate the psi and gph or is there one kind I should buy that can do that?

LS1MCSS

iTrader: (18)

How is your fuel system setup now? We need this info so we can tell you what you need to fix the problem? Pictures would help.

Try2pass

My fuel system is a non return from the engine to the fuel tank system with the EP381 fuel pump in the tank, a fuel filter mounted outside of the tank and a regulator mounted outside the tank that I haven't located yet. I don't know if the regulator is "adjustable" or is it that I just need a more powerful volume fuel pump and would that aeromotive 340 stealth be the one and would the regulator keep it in "line" and not let it pump too much? I have determined that my injectors should be 42lb and when it goes to the shop we can check on that I suppose by getting a number off of the injectors? Someday I really would like to find a used LS7 and put that in there and maybe now is the time to set up for that if it won't hurt what I got now. Somewhere I read that a LS7 needs a flow of 50gph vs the LS3 at 41gph. I guess the injectors are the same size. Again, WHATDAIDONOW?

LS1MCSS

iTrader: (18)

That's what regulators do. They keep the pressure where it is supposed to be and let extra(not needed) fuel return to the tank. The pump should always put out more pressure than you need to run and the regulator keeps the pressure where it needs to be at the engine.

Try2pass

Sounds like maybe I should get the big (340 stealth), up to 90 psi and 90 gph pump, and maybe change the fuel filter and that oughta do it. The regulator should take care of what the fuel is delivered at both psi and gph and the pump will supply it. I am extrapolating out of all of this that the big fuel pump won't hurt anything in the engine as the regulator, again, will take care of it.