I tend to agree with Z U L8r, and it goes back to what i was saying earlier.

There are LOAD BEARING dynos which tend to typically read LOWER than Acceleration Dynos aka Dynojet.

Most "tuners" prefer that load bearing, its alot more accurate.

Problem is the dynos are usually 2-3 times the price.

There is a difference between calculating hp based on how fast a roller accelerates and calculating horsepower based upon load to the wheels.

Actual HP versus Intertial HP