fuel pressure to low at WOT
 

My fuel pressure drops to about 5 1/2 - 6 psi at WOT

This is a 454 blower motor so I don't want to run lean.

It use to be worse until I changed some fittings around and drilled out my openings in my fuel filter housing and fittings. but its still to low.

My current setup is a Holley black electric pump with all 8-AN fittings. , The system starts with the pickup, then check valve at the pump, then pump, filter, regulator mounted at carb and then carb. The pressure sensor is at the carb.

I can get a aeromotive pump from a friend but it pushes 350 gph and makes 45 psi. I am scared that is to much pressure and it should have a return line installed. But I am not familiar on how to install a return line. Or do I even need one???


So my question are ;

Do I get a larger pump that don't need a return line???
Is the Aeromotive pump fine with no return line ???
Do I use the aeromotive pump with a return line???
How do I run a return line????

Thanks
Paul

Re: fuel pressure to low at WOT
 

5-6 lbs @ WOT your ok.

You don't want less than 3

Re: fuel pressure to low at WOT
 

I installed a pressure switch from NOS that activates an alarm and turns on a pro-light if my fuel pressure drops below 4psi.

If your interested I can find the part number.

Also, my oil pressure, water temp, drive and PS fluid bottles will trigger the same alarm.

Cheap insurance.

I also switched my regulator to return style after the fuel log. Dead head regulators kill electic pumps. Also dramatically reduce their advertised flow rates.

Re: fuel pressure to low at WOT
 

That aeromotive pumps alot of fuel. The return line is simple but most people use a fuel cooler on the return because the pump can heat the fuel.

Might not apply but is your tank pick up large enough?

My Whipple kit came with a malory pump and regulator. The pump is rated for 14 lbs and the regulator is set @ 8, with no return.

I also remember reading check valves can be restictive.

Re: fuel pressure to low at WOT
 

as pure said, the mallory is a great set up, a lil better than the holley. -8 is ok. more important is the fittings you used. if they reduce down to much then no matter what size fuel line you have it will only flow as much as that fitting's i.d allow's. for most blower applications a 1/2" dia. pickup is used, no check valve at the tank, all radiused fittings and hose ends. -10 to the fuel/ water filter, -10 to pump. -8 from pump to carb/ regulator. typicaly the mallory will not heat your fuel by dead heading for it is internally by-passed i believe.

as wobble said the reutrn style reg is best, and i would cool the fuel as well.

good luck.