Is anybody using the Holley Red Electric fuel pump? Car is running out of fuel in higher RPM's, I have a fuel pressure gauge mounted to my cowl and can watch my PSI dip down below 2, with a cheap Auto Zone 30gph pump. I used this one temporarily while I get the car tuned, now I am ready to buy a better pump. I think the Holly Blue may be more than I need, its rated up to 14 psi, I only need 6-7 psi, but I want to make sure I have enough gph for higher RPM's. The flow specs on Hollys web site show this flows pretty good at 2-4 PSI, which is where I am concerned. Anyways, it will be more than triple what I have now...it is maybe putting out 25-30 gph at 2-3 psi, so the Holley Red looks good to me.They rate theirs at 67gph at 4psi. Just looking for opinions. My 68 coupe has a fresh 390, big cam, holly 750 3310 carb, c6 trans. It runs like BEAST until it hits about 5500 rpm's, thats where I notice the fuel psi way down, and its stops making power. I'm positive the problem is low fuel psi, and wanted your guys' opinions on hi pressure electric pumps before buying.

 

I can't recommend any specific type of fuel pump for your application. I do know that carbs don't require anywhere near 14 psi of pressure...you would flood the carb. You are right, typically a carb only needs about 6-7 psi and if your pump delivers more you will have problems unless you install a pressure regulatornear the carb with a return line like with a fuel injection system.

This is a possibility to ensure you always have 6-7 psi, but I wouldn't install the 14 psi pump without a fuel pressure regulator that was set to the correct pressure.

You are doing the right thing by asking around, I'd certain check with some more experts too. There is probably a better way of doing than I just described.

 

Unless your are full-on racing,I would stick with a mechanical fuel pump from one of the big names. My 2 cents.

 

For what it is worth, I ripped out all the old fuel line andinstalled a new Barry Grant fuel system comprised of #10 line to the regulator, #8 feed line,with a 220 gph pump, return line, inline filter,and a regulator. This way, I know I have fuel when I need it. Stock lines will lean out when you start playing with performance level power. This is for my 383 running a Holley 750 double pumper making around 450hp. I would think your 390 would need close to the same. If you decide to use stock fuel lines, you are just taking a chance of lean out and burning pistons. Barry Grant sells a street style pump, but it looks basically the same as the race pump with a return line from the carb instead of from the pump. I chose the pump return to limit the amount of line I had to run.

 

Just wanted to update: I installed a Holley Red the other day, and it fixed my problem... PSI at idle is around 6-7, and only drops a little bit to maybe 4.5-5 psi under heavy accelleration. This pump puts out 3 times the volume of my cheap Airtex brand from Auto Zone.With the old pump,I would hit 4500 rpms and it would stop making power...now Ican revit to about 6000 rpms and it is stillaccellerating very hard. This pump is a little louder than the other, but cant hear it when driving, or idling either. Very happy with it! By the way, the car has 1/2" aluminum fuel lines running all the way from the back to the inline filter at the engine...Highly recommend this, or at least 3/8", and dont use rubber hose!

 

Congrats. Thanks for update! Excellent information. I'm seriously considering a stroker kit when I re-do the engine. This is information I'll keep in mind when laying out the fuel system.