Re: SL55 Fuel Pump Fact, Fiction or Matter of Opinion?
The weather is improving and I will be doing the crossfire thing soon again.
A/F issues are determined by the amount of oxygen and fuel induced to the cyclinder. Balanced f/a is luck as much as any other thing. Air density and fuel delivery affect the resulting numbers and going lean is a function of the the boost.
We keep adding air O2 but the fuel is going down due to the increased pressure at the manifold pushing back on the pintel of the fuel injector WHICH REDUCES THE EFFECTIVE PRESSURE which is forcing the fuel into the engine.
If you up the pressure you up the deliver with the same injector duty cycle. The computer has a fuel map that alters the duty cycle to allow more fuel and it the map is off, there are lean or rich spots. Adding an external controller to adjust the fuel pressure, will solve the issue and keep a consistant pressure. I have done this and found that it works and Rob is going ahead of me cause I work and have had my cataracts removed which is an interesting issue in its own right.
The stock pump is 60 PSIG and can feed the engine up to about 80 - been there and done that. Went from 17: 1 at stacked to 9:1 which was way too rich. Good now you know how, just have to correct your Kentuckey windage to get - keep it on track. Sadly the FPR in the car is a filter and regulator, great idea for the street but has limitations as it is not adjustable (easily). Adding fuel is as easy as getting a regulator and filter from Needswings or finding one that you like and working out the details to adjust it.
Bigger pumps will allow more fuel and may have higher flow capacity, but again are limited by the factory regulator. This regulator POP'S off the pressure if it gets over the factory setting. THat pressure is set at about 60 PSIG from the factory, I believe that it should be a few PSIG higher from the get go.
Ill be doing the adjustable FRP and let you know how that works in concert with the Zeitronix secondary controller.. The solution is at hand, its just a matter of making it repeatable on all srts without much intervention other than when YOU plug in YOUR laptop to dial the F/A number setpoint.
ENJOY, Woody