Ed,
The default staging threshold of my EC2’s that were
updated in February of this year is a value of 21 which corresponds to a
staging MAP of 20.5” Hg. This is in a region where it is more
likely to encounter the fuel flow error than the staging MAP of 15” Hg
that you are using. It seems to me that it is useful to know that the
error exists and to be aware of the conditions where it might become a problem.
It is my intention to conduct flight testing specifically designed
to further verify the magnitude of the error. It would be nice if I found
that no error exists, but that seems very unlikely.
Steve
From: Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ed Anderson
Sent: Friday, November 05, 2010 9:23 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Fuel Useage error?
I think that
answer my question to you about why my total fuel consumption measure by my PW
integration system did not seem to reflect the magnitude of the errors we had
discussed.
Since I
seldom (if ever - except during taxi/landing) operate near or below my staging
point in flight - and I do not appear to be getting (at least the
magnitude) error when I compare my instruments "Fuel Used" amount
with what I measure when I fill up the tanks. My manifold pressure
in flight rarely drops below 20-22 " hg.
One reason is
I generally run with my throttle wide open to reduce pumping loses and I tweak
the mixture to keep it running smoothly - so my staging point (around 15"
Hg) is only seen on the ground and while in the landing pattern. Since I
spend very little time in those regimes, I am seldom near or below my staging
point.
So that could
explain why I am apparently not seeing the difference you data indicates