Message-ID: <421FE4E6.6040700@logan.com>
Date: Fri, 25 Feb 2005 21:54:30 -0500
From: Rob Logan <rob@logan.com>
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To: Lancair Mailing List <lml@lancaironline.net>
Subject: Re: [LML] Re: FADEC Rough idle explanation
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 > It starts out with the timing near TDC for the first pop,
 > then sets it as needed to hold the optimal thetaPP.

cool, so we might soon have a computer that can seek
peek pressure at 16^o After Top Dead Center to maximize the area
under the curve after TDC (HP). This is perfect if one changes
the the quality or amount (mixture) of fuel. (rate of fuel burn)

But if we have another computer to seek the perfect
.072 Fuel/Air mixture, we can eliminate the inefficiencys
of amount of fuel (mixture) toward our goal of best power.

Aerosance address both issues. While Aerosance can't
directly measure ICP like PRISM can. (we know how hard
it is to find sensors that can measure ICP otherwise
George and others would have done it sooner!) It does
have a huge number of maps that tracks the amount of
air (temp, MAP, RPM) for a metered .072 F/A and sets
the spark advance for a given type of fuel (100LL) by
looking it up in a table.

now are all the Aerosance sensors (MAP, temp, RPM, cross
checked with EGT and CHT) more reliable than PRISM's ICP
sensor cross checked with EGT and CHT?

is the inter cycle variability so great the problem
can't be monitored this closely?

When would you not want to run at best power?
ie: (neck out on a limb) my guess with no data to back
it up is 240HP at best power will have a lower CHT
(lower ICP) than 240HP lean of stociametric (with a higher
MAP to make the same HP) if both use a perfect 16^o thetaPP.

	std mag	Rob