What should the stock fuel pressure be? If I raise it would I get any HP Gains?

[whitebullet]

I've heard that raising your fuel pressure a couple a psi will give you some HP, I have a 94 GT 5.0 engine 5 speed with SLP Loudmouth's, C&L 76 mm air intake kit, BBK 70mm Throttle body, BBK power pulleys, Off-road X pipe, BBK Headers, MSD Ignition, UPR Billet Aluminum smog pump eliminator, Autolite XP plugs and that's basically it for the motor but I have a Performance Products Fuel pressure gauge and it reads 32 psi with the car running and 40 psi with the car off , I heard it should be around 40 psi with the car running what do you guys think? should I buy a fuel pressure regulator and raise the fuel pressure??

 

[Paul]

39-40 psi with the vacuum unhooked is the factory setting.

I've heard a few horsepowers can be gained by bumping to 42-44 psi, but cannot validate with any certainty as I've not witnessed the difference firsthand or seen any verifiable data on the topic.

Paul.

 

[Matt94GT]

I had mine at 46 at one point got a few backfires here and there so I brought it back down and didnt notice any difference.

 

[2slo95fiveoh]

My factory FPR with factory fuel rails is a very steady 42-43... :icon_rr:

 

[94 DropTop]

i keep mine set at 40 with the vac unhooked.

 

[phantom09086]

yup I keep mine at 39 vac unhooked , and I have 30LB injectors, car runs fine.

 

[DFG_magic]

My factory FPR with factory fuel rails is a very steady 42-43... :icon_rr:

Is your stock regulator pinched? Seems pretty high for stock. Like Paul said, should be at 39psi stock. Mine was rock solid at 39 psi stock; I bumped it to a little under 41 psi when I installed my adj. regulator and noticed a slight difference over 39. This is only seat of the pants, so who knows for sure if there is a difference. Only way to tell is on the dyno.

 

[DFG_magic]

Holy old thread. :BangHead:

 

[2slo95fiveoh]

Ha, my thoughts exactly...
Thinking back, that may have been with stock regulator and rails, but I did have a 255lph fuel pump, not sure if that made a
difference or not... Now my cars fuel pressure is at zero, cause it doesn't have an engine in it... :crybaby2: