i was just wondering , i have a holley red fuel pump 7 psi , do i need to run a regualtor with it? i dont have one i thought 7 psi wasent really needed being low pressure
From my experience with racers who run carbs, Yes. A 1/4 or 1/2 lb change in FP made a difference. my I assume you meant for drag racing??
I've seen Holley carbs getting flooded with anything over 6 psi, in which case, a regulator was necessary. Other carbs seem to hold more pressure on the float's needle valves.
with a good needle and seat it will probably work but it'l be close. My best advice is to give it a shot. With the pump on it will flood without the engine running (out of the bowl vents). If it does then u know what to do.
Use a regulator. Period. What happens if the pump spikes and pumps out a bit more than 7 psi? Chances are that it won't happen but why take the chance. The Holley regulators are cheap and work well.
Use a regulator set at 6 1/2PSI. Run a return line to the tank #4 or 6. It'll help keep the pump cooler and last longer.
on the topic, how do you adjust the holley regulator, I got the summit kit, but it didn't have any paperwork for the regulator, and I put a fuel pressure guage just past the reg. and it doesn't work, at all, what kind of guages are you all using?
Holley recommends 3 psi at the carb. If you are running up to 6 psi the float will easily compensate for the pressure but if you are running more than that you need a regulator. Another thought is that if your carb is set with 6psi at an idle then when you are racing down the strip your pressure at the carb will drop and your fuel level in the bowls will be lower meaning a leaner mixture. If you run a 3 psi regulator then this leaning out is minimized. Paul
i think holley says 3 psi as a minimum under full acceleration. their street pump sold without reg puts out what? 6-7 psi if i recall correctly. i used to always run 7-7 1/2 psi fuel when i ran gas, with no problems on street or track. the street holley pump sold without reg is intended to be run without a reg and not be a problem.
