Hints wanted

[Mike Pitts]

$0253 = (VE * ((kPaMAP / TempRelated) * 0.6235)) / ReferencePulseCounts

VE - Lookup result from Volumetric Efficiency table

kPaMAP - MAP converted to 16-bit fixed point kPa value

TempRelated - Difference of IAT and CoolantTemp is used to index into
a couple of tables, the results of those lookups, with some additional math
create this value.

ReferencePulseCounts - Directly from the reference pulse counter.

The above is a formula used in my calibration.  I'm wondering is anyone
knows for certain what it is calculating.  The result ($0253) is used as an
index for *alot* of table lookups.

Is this the speed density equation?  Is it calculating airflow?  That's the
only thing it seems like it could be doing.  If so, is it in grams/sec?

BTW: I've figured out that the IRQ interrupt is triggered by reference
pulses.  It sets up TOC1 to occur 1.67 ms later.  TOC1 then reads the
ESC monitor, finds the difference in spark control counts,  then adjusts
the result according to RPM.

TIA,
-Mike
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Mike Pitts
Delray Beach, FL
mpitts at emi.net
http://www.emi.net/~mpitts/mike.htm
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