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I can see where that would be good, as long as the EC-2 fuel map knows how
to adjust for the variations in fuel pressure. So, then the EC-2 will
automatically adjust for my "poor man's turbo (ram air system)?
The
EC-2 doesn't monitor the fuel pressure, if that's what you're
asking. It expects it to be repeatable. When you get the
unit, it will have the factory defaults in it, which should work well
enough to get the engine running the first time. Once everything is
working properly, you go through the entire range of MAP on the
ground, from idle to full throttle. Along the way, you calibrate
the mixture, so that it's correct for your installation. If your fuel
pressure changes a bit along the way, it won't matter, as long as it's
repeatable. In other words, if your regulator is screwed up, and
wallows up and down in pressure randomly, you're going to have problems.
If however it always holds perfectly over most of the range, then falls off
slightly at higher power, you'll be OK, because you programmed the EC-2
under these same conditions.
You should
probably now be wondering (again <g>) why it makes any difference if
you have a regulator that tracks pressure, since you have to program the
EC-2 anyway. The EC-2 has lots of adjustment, but I'm guessing that you
could run out room to adjust under worst case
conditions. Without the pressure referenced regulator, you'd
need to turn the mixture way down at low power, and way up at higher
power. Maybe you'd have enough adjustment, and maybe not. You
just improve your odds greatly by having the better
regulator.
As for your
ram air system, if this only works in flight, as I imagine, then
you'll only be able to tune this in flight. You will have an idea
how close you'll be when you do the ground tuning. If you find that
all your high power MAP's need to be enrichened a little, then the slight ram air MAP will need to be
enrichened a little also. You could also use the trick that Tracy
mentioned for idle, where you widen the "window" of settings that you calibrate
with each push of the set button. When you "set" the highest MAP that you
can attain on the ground, you'll actually be putting the same setting in
the next inch or two of MAP above that
point.
If you aren't
familiar with the calibration routine, some of this may not make
sense. The bottom line is that it won't be a problem.
Sounds reasonable. I
initially set mine for 45psi, but there's an adjustment screw and know how to
use it! However, my guage is really an oil pressure guage and probably
isn't sensitive enough for the accuracy needed here. I'll wait for my EIS
to set it more precisely.
To be honest,
I think I used an 80 psi gauge, and just took my best shot at 43.5.
You could leave yours alone if it's anywhere around that area, and be perfectly
fine.
Thanks for the lesson in fuel
pressure regulators,
Most
welcome.
Rusty (got
brakes again, full fuel, 2 more degrees of pitch, and good weather for the
weekend)
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