Does anyone know what pump GM uses on the factory ZO6 LS7s. I have a weldon 600-A external now. Its just barely doing the job. Border line on maintaning the 58 to 60 PSI I need for the LS7 motor. I am thinking about going to a different fuel tank and installing an intake pump. What do you guys think will be enough pump?? I have a power tune done by Speartech, an headers, thats all.

 

That pump should be plenty for that motor one Walbro pump could keep up with 600rwhp. How are you regulating it? What size lines are you using?

Nate

 

I have the weldon bypass regulator they recommended. I am running a 10AN from the tank to the filter. Then a 10AN to the inlet side of the pump. Then a 6AN from the pump to the regulator. A 6AN from the regulator to the fuel rail, an a 6AN bypass line back to the tank. I was just wondering if maybe I should do away with the return & dead head it like the factory does? But I think the factory pump has an internal bypass built in. What would you suggest? Any help would be great.

 

Your regulator needs to be after the fuel rails. You are going to have pressure drops across the rails and injectors, so you need to maintain 58psi after all your losses across the rails...

 

That setup is about prefect you should have no problem holding 58 psi with that pump. Do you possibly have a voltage drop under load? That is about the only thing I can think of that would cause such an issue.

Nate

 

If thats the case, how do you tie the regulator in to the fuel rails. I have the fuel infeed in the drivers rail. So you are saying , if I do it your way I would tie into the back if the passenger rail, Correct?

 

Yes, since you have a crossover... The FPR should be the last step before the return line. At least thats the way I had always been taught.

 

After locating the reg after the rails, or on the out side of the rails, make sure you have the reg set to the proper fuel pressure. I have my in pumps/lines at the rear of my rails, in a crossover, then on the front rails they hook up into the regulator in their own crossover. here's a pic showing the reg tied in as a crossover using the front outlets, then the return comes out the bottom of the reg to tank.

Robert

 

Awesome looking engine, Robert!