Re: Vapor Pressure
Nomad,
Without getting into the science of gas laws and partial pressures, think of the V.P. number as an effect that subtracts from the barometer. An increase in V.P. means the air is carrying more water vapor I.E: slower E.T. So, a vapor pressure change of plus .25 (.40 to .65) would have the same effect as the barometer dropping from 29.75 to 29.50.
I have found the effect of V.P. on car performance to be linear and consistent on gasoline burning engines both normally aspirated and supercharged.
Now for the cherry on top: .06-.07 change in V.P.=.01
See you at the races,
Wayne Kerr
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