1/4 mile times and HP

Drag Racers.....what do you think of this chart?

http://www.enginefactory.com/calculate_your_horsepower.htm

Like it said these are theoretical best times, but it was actually quite close to what I am running. With me in the car it weighs ~3600 lbs with 375-400 HP at the flywheel, and I'm running 12.8 seconds. The chart says 12.5 sec.

Not bad at all .