I am looking at running a engine (350) with arround 480hp and I want to run arround a 150 single stage or a 225 duel stage or 225 on a progressive controller. I currently am changing to a carb it is a 750 holley double pumper. Now my question....

I bought a Holley black electric fuel pump and the flow rates on it are 140gph full flow and 120 at 9psi. The preasure on the pump is factory pre set at 15 psi.

My question is when I hit the nitrous will the fuel preasure drop off from the sudden shot or will the fuel preasure remain the same? I know the extra flow is there but I don't know if the extra preasure is there.


I worked out the formula and I know I have the fuel volume with that pump.

 

With the 150 shot i don t Think you will have any problems with fuel pressure drop, with that pump Assuming that you run it on a dedicated relay, with a proper gauge power wire to insure constant voltage. ALso i would run 1/2" line with it up to the regulater. With the 200+ system i would run the nitrous system on a dedicated fuel supply and pump of its own.

 

Yea I am running a 1/2" aluminum fuel line from the tank to the regulator. I have a spare holley electric red pump in the garrage I just don't know if i can trust it, it was given to me by a friend and it doesn't look like it is in good shape but it does pump plenty good. I am just worried about how long it would last.

 

Here is the heart of my question if I have a pump that has 15psi and I run the engine at 8psi and when the fuel silonoid opens it takes a mininum of 6psi. That combo maxes out my fuel pump psi but is that how it works???

I also want to know if I really should run a return line to fight preasure drop?

 

You should mock up your fuel system and flow test it to
see if your holley black pump can supply fuel at the right
volume and pressure to satisfy both your motor and nitrous system at peak hp.


Temporarly install the largest fuel calibration jet supplied with
your NOS kit in your NOS plate.
Set up your two holley fuel bowl assemblies and NOS plate to flow fuel through their respective lines and regulators and into a bucket infront of your car. Hook up pressure gauges on both systems and read the pressures while flowing the whole system.
That's the only way to tell for sure if the pump can supply
the nessessary fuel at the required pressure for both the motor and NOS.
The pressure at the carb (fuel bowls) can drop to 3 to 4 psi,
but the pressure at the NOS plate must be 5 to 6psi and constant.

If the pump can't keep up then build a separate fuel system
for the NOS.
Your fuel pump will have slightly more capacity with the motor running (13.5v dc) than when off (12v dc battery voltage).

 

Check out magna flow products they make a regulater with pressure drop concern's. summit racing has them listed in in air and fuel delivery hardcore section