These are the specifics about the problems I am having with on-line density calcs. I logged onto
www.airdensityonline.com Bonneville data is:
temp = 37.0 degrees fahrenheit
corrected baro = 30.38 in Hg
52% relative humidity
uncorrected baro = 26.06 in Hg
elev = 4212.6 feet
A "tit stiffener" is what we call this weather.
Input into the on-line calculator at
http://wahiduddin.net/calc/calc_hp_abs.htm or
http://www.anycalculator.com/enginehorsepower.htm (they are the same)
air temp = 37.0 degrees Fahrenheit
absolute pressure = 30.38 in Hg (corrected baro used)
relative humidity = 52 percent
Output is:
SAE relative horsepower = 109.1 percent
dyno correction factor is 0.917
air density = 1.297 kilos per cubic meter
density altitude = -1965 feet
ICAO relative density = 105.9 percent
virtual temperature = 37.7 degrees fahrenheit
vapor pressure = 0.115 in Hg
Input into the on-line calculator at
www.csgnetwork.com/relhumhpcalc.html is:
current air temp = 37.0 degrees Fahrenheit
ambient barometric pressure = 26.06 in Hg (uncorrected pressure used)
ambient relative humidity = 52 percent
physical or pressure altitude = 4212.6 feet
Output is:
calculated relative horsepower to rated = 75.8 percent
calculated dynomometer correction factor = 1.320
calculated air pressure = 22.24 in Hg
calculated vapor pressure = 0.114 in Hg
Big differences in answers. Any ideas?