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Message
I have seen the FP changing
from 35 psi at low RPM to
50 psi at high boost?
Hi
Buly,
What you describe here
is exactly how it's supposed to work, and whether you believe it or not, it's
making your tuning life easier. Here's why...
Think about how a fuel
injector works. The fuel rail has a high pressure in it, and the intake
end of the injector is in a lower pressure area. To actuate the injector,
all you're doing is opening it. The rate of fuel flow is controlled by the
difference between the pressure in the fuel rail, and the pressure in your
intake.
As you can see, if you
were to set your fuel pressure at a fixed point, then run lots of boost, there
would be very little flow across the injector, because the differential pressure
would be low. This will make your injector appear to get smaller as boost
increases, and eventually you will go lean. Recall also that lean + boost
= rebuild :-(
The whole idea of the
rising rate fuel pressure regulator is to keep the differential pressure close
to the same, so the injector flows the same rate of fuel regardless of the
MAP. This makes it easier for the engine computer to control idle to
max boost mixtures.
Cheers,
Rusty (Stopped to eat in Greenville AL
in George's honor today <g>)
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