Looking for a chart or the formula

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Mar 29, 2007 | 08:22 PM

NewYork Art

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Staging Lane

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From: New York

Looking for a chart or the formula

Looking for a chart that will tell me the temperture drop and the air flow on the intake.... on how it affects combustion and horse power gain.

Mar 29, 2007 | 08:38 PM

SSpdDmon

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From: Commerce Twp, MI

You mean like the formulas the SAE corrections use on the dyno to account for changes in atmospheric conditions?

Mar 29, 2007 | 09:06 PM

NewYork Art

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Staging Lane

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From: New York

yes
That should do

Mar 29, 2007 | 10:32 PM

SSpdDmon

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From: Commerce Twp, MI

Well, hopefully someone has that. I don't...but someone here might.

Mar 29, 2007 | 10:45 PM

RedHardSupra

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From: Laurel, MD

airflow=CYL * RPM/120 * VE * rho * CYLVOL

where rho is the air density, and you can get it with:
rho=1.2929 * 273.15/TEMP * MAP/101.325
there's also a more precise formula that takes humidity into account, but since our cars dont have a humidity sensor, we can blissfully ignore it.

TEMP (in Kelvin!) is a blend of ECT and IAT according to bias tables and airflow amount.
CYL is number of cylinders
CYLVOL is cylinder volume in Liters
MAP is MAP in kPa