I took my car to the track yesterday and was convienently logging the data off of my car. I noticed that Datamaster had a dyno built into its software.

I set the beginning and end points properly and it gave me a great number. I really don't believe it, so thats why I was asking this question.

By the way, Datamaster said I had 362 ft/lbs torque and 250 hp.

 

could be very accurate.

 

Some just use:

(Trap speed) squared/ETxWeight/1000, and that product divided by 9.1. This is based on a 1/4 mile, but you can get the drift, just from memory, so there might be a misplaced */*. I'd bet googling would reveal some others, or some time with a physics book.

 

If you log speed and RPM at a fast rate and with some good resolution you can then derive acceleration using some math. Take the acceleration and the vehicle weight and you've got horsepower because horsepower is the measurement of how fast you do work (moving a mass from point A to point B).