I know the mph posted on your time slip after a 1/4 mile run is an average for so many of the closing feet.
What distance is the average calculated from?

Thanks

 

I think the last 100'.(Not positive, just thinking out loud.)

 

It's the last 66 feet before the 1/4 mile mark.

 

Used to be 66 feet before and 66 feet after the e/t light. Nhra changed it a few years ago to give more shut down room. Speeds are now a little slower because the average is 33 feet before the end of the quarter mile. What I am saying is that they used to use 3 lights, speed start, e/t and speed stop (66 feet past the e/t light.) Now, they use only 2 lights. Speed start and combined speed stop and e/t light. A 110 mph car will probably read about 1/2 mph slower than it would have the old way. A Top Fuel car will read about 2-3 mph slower. Insurance companies do not like to hear about 335-340 mph speeds. Skip

 

wait so they take your speed at two points and average it? Or they take the time between the two points and come up with a speed?

/would make a difference since your still accelerating right?

 

There is a spped trap just before the finish line, 66 ft to be exact. 66 feet before you hit the finish line you trip a light, and at the finish line there is another light that stops your overall ET and the speed trap timing. So your MPH is determined by your speed inside that speed trap.

 

The first light starts the speed clock and the 2nd light stops it. Your true speed will be in the center of the 2 lights. The lights measure time, that is converted into speed. Skip

 

I had my speed posted on a yellow slip this weekend...76 in a 60
Whooooooo whoooooooo!!!

 

hahahahahah
Shane