Here is my Combo: WHAT FUEL PRES DO SHOULD I USE?

[lucheski]

What Fuel pressure should I set? Im thinking about 41 or 42PSI
For now, Im still using the STOCK 60mm TB
I will be getting a 70MM soon

1989 Grand Marquis 302 Block
Bored .030 over
Sterling Hypereutectic Pistons
Federal-Mogul Chromemoly Rings
Edelbrock Performer RPM "Typhoon" Intake (Ported)
1969 351W Heads (30 hours of hand porting)
60cc combustion chambers machined to 50cc
10.5:1 Compression Ratio
Ford Racing F-303 Cam
Sealed Power Hardened Pushrods
Sealed Power Valve Springs
TRW Guideplates
Clevite Studs (For Roller Rockers)
Cloyes Double-Roller Timing Chain
Harland Sharp 1.6 Ratio Roller Rockers
A9L Mass Air Computer
70MM Cobra Mass Air Flow Sensor
Chromed Cold Air Intake Kit
Ford Racing 24lb/hr Fuel Injectors
MAC Equal Length Headers
MAC Offroad H-Pipe with Flowmaster Muffler
Throttle Body Bypass
Aeromotive Adjustable Fuel Pressure Regulator
Trickflow 1" Phenolic Spacer for Edelbrock Performer
Summit Racing 255Lph Fuel Pump

OTHER STUFF

Weld Racing Wheels
Milodon Chrome Valve Covers
3.55 Posi Rearend
3" Cowl Hood
New Dual Friction Racing Clutch
New Resurfaced Flywheel

[88fivepointoh]

42-45PSI...

So is that with the vacuum line disconnected or connected? 42-45psi. may be a little rich, don't you think? Considering that he's running 24lb. injectors.

[88fivepointoh]

no, I think its good, better rich than lean, and I ran 42psi on my stang and it works great.

[Dark_5.0]

You should run 38 psi with 24 # injectors I make more power than you and my car runs a little rich on the dyno @ 38psi.

You really never have to boost the fuel pressure past 38-40 psi unless your injectors are too small. There is more to how much fuel your engine gets than just fuel pressure. 24 # injectors can support over 400 RWHP @ 38psi on a mass air car.

On mass air cars the ecu will adjust the pulse width of the injector to compensate for more air flow.

[lucheski]

you had it on a dyno? whats your A/F ratio? how rich is it? Whats your combo?

[88fivepointoh]

On my car with 24lb injectors I was constantly lean until i boosted it to 42lbs of pressure. I had a A/f gauge installed and at WOT i was lean at 38psi... so that is why i keep saying 42. Every Engine is different.. The best way to tune a car is go by what your engine tells you with its AF ratio and by the seat of your pants.

[poonstang90lx]

I have a 331 with the holley systemaxII kit and 30lb injectors, I only run 36 lbs with the vac. disconnected. Why dont you start at 39lb, just like Ford

[lucheski]

Thanks for all your input....I tried it at 37-39PSI But I find it pulling harder when I set 41-43PSi

[88fivepointoh]

40's are best... good luck buddy!