Years ago some Chrysler engineers came up with a horse power calculating formula, which used trap speed and total vehicle weight. It worked well, too, but I can't remember what it was. Oh, they figured it out by dyno-ing their hemi drag engines and then putting that engine in a car an making time runs. In other words, they "back figured" the formula, using a company main frame computer (this was in the days before the PC was common.)
It doesn't matter these days, though, as NHRA shortened the speed trap at the finish line, by cutting off the back half of it! The traps used to be 66 ft. long both before and after the finish line, so as to get an average speed when one crossed that line. Because Top Fuel cars started going so darned fast, and because drivers would hold the throttle down 66 ft. past the finish line, NHRA just eliminated that back half of the speed traps so that fast cars wouldn't run off the end of the strip.
The shortened speed trap messed up the results of the formula.
