RE: another darn ryobi post (ryobi performance modification, analysis and comparison)
Ok, sorry for the way too complicated explanation of correcting data. It's not too hard really.
1) Measure RPM and air temperature.
2) Add 460 to the air temp.
3) Divide that result by 519
4) Take the square root of that result. That number should be between .96 and 1.04
5) Take the measured RPM and divide it by the number you got in 4)
That's the corrected RPM.
Now you can compare data taken at different air temperatures.
diceco