In Reply to: Wrong... posted by Omar on September 14, 2001 at 12:27:23:
So for those, you should correctly apply some other loss factor, but for E36 M3, 1.21 is the one.
If you use the same 1.21 factor, the horsepower numbers for 01 M3 and 00 M5 will be understated as shown below:
(hp figures are from AA dyno page)
2000 M5 304hp X 1.21 = 368hp
2001 M3 248hp X 1.21 = 300hp
I have used both dynojet and mustang dynos and there is a significant difference in the numbers they generate. From my experience dynojet numbers are about 15%-17% more than the mustang's.
One method to figure out what the correct/estimate horsepower for a car (in any type of dyno) is to compare the numbers to numbers from a stock car (from the same dyno, same conditions).
Even doing this is not going to give you the correct drivetrain loss. At the end of the day the rear wheel horsepower is what counts...