Fuel pressure?

[restomod22]

I bought a Holley mechanical fuel pump recently that is too much pressure for my carb. I bought a regulator for the needed adjustment. The question is, if I decide later to add a larger cfm carb will I need to increase fuel pressure or is this unrelated? I know different carbs may need different pressures, but is it based on the mfg? Are all Edelbrocks 6psi?

Edit: I guess when I think about it, psi is constant over any volume, so it should be unrelated to cfm. So, why are there different psi rated pumps? Is it for running dual carbs??

 

[ForceFed70]

I bought a Holley mechanical fuel pump recently that is too much pressure for my carb. I bought a regulator for the needed adjustment. The question is, if I decide later to add a larger cfm carb will I need to increase fuel pressure or is this unrelated? I know different carbs may need different pressures, but is it based on the mfg? Are all Edelbrocks 6psi?

Edit: I guess when I think about it, psi is constant over any volume, so it should be unrelated to cfm. So, why are there different psi rated pumps? Is it for running dual carbs??

Usually there are only high pressure(EFI) low pressure(carbed) pumps.

Some are rated at different PSI's becasue they are either ment to be run with a regulator, or internally regulated. The ones ment to run with regulator give you the advantage of being able to adjust the pressure using the regulator.

Just about all carbs are ment to operate at 6psi. Swapping to a different manufacturer or a different flow rating won't be a problem in this regard.

 

[restomod22]

Some are rated at different PSI's becasue they are either ment to be run with a regulator, or internally regulated. The ones ment to run with regulator give you the advantage of being able to adjust the pressure using the regulator.QUOTE]

OK, but why would you want to adjust the psi? Why wouldn't all fuel pumps be internally regulated for 6psi?

 

[84convertablegt]

because the higher psi brings more fuel faster on demand to the regulator that way under high rpm situations you are starving for fuel. also, race carbs do benefit from higher psi.. some like 9 and some like more.