TURK,
For an incredibly long and painful discussion on density altitude and how to calculate it go to:
http://rshelq.home.sprynet.com/density_altitude.htm
Density altitude makes a huge difference! I found an engine tuner's calculator at the following website:
http://rshelq.home.sprynet.com/calc_hp_dp.htm
Using the following variables:
Air Temperature 100 degrees F
Altimeter Setting 30.10 inches Hg
Dew Point 42 degrees F
Altitude 4412 feet
I came up with the following calculations:
Relative Horsepower 82.6%
Air Density .9678 kg/m3
Relative Air Density 79%
Density Altitude 7847 feet
Virtual Temperature 102.2 deg F
Actual Air Pressure 25.61 inches Hg
Actual Vapor Pressure .268 inches Hg
Relative Humidity 13.9 %
Dyno Correction Factor 1.21
Note the density altitude of 7847 feet and Dyno correction factor of 1.21.
Plugging the Density altitude of 7847 into the calculator Bill provided I get 83.3 HP loss to the rear wheels on the chasis dyno due to the high elevation and temperature in Reno.
354 + 83.3 = 437.3 to the rear wheels
437.3 X 1.20 = 524.8 at the flywheel
Not bad my friend, not bad at all!
Jeff