"Live" from Jegs Northern Sportsnationals 2012

[Stewart Way]

Being a numbers guy I thought I'd run some numbers on trap speed and time. Not trying to stir anything, just add some logic and engineering to this discussion.
Common number for speed is 60 mph = 88 feet per second (fps). With that we know 120 mph = 176 fps. The speed trap is 66 ft long so it takes .375 seconds to go thru the traps at 120mph. 66/176 = .375. The speed given on the timeslip is not a top speed but is the average over the last 66 feet of the 1320.
Now if we look at 125 mph or 183.3 fps the time required to go 66 feet goes down to .360 seconds. 130 mph is .346. So a 10 mph change from 120 to 130 mph only takes .029 sec.
So the opposite is true. If you dump .029 sec in the last 66 feet starting at 130 mph you will read 120 mph.
If we say the car has a 3 foot nose or the distance from the nose to the cross section on the tire where the beam would hit with the nose up all that has to be done to see the difference is redue the calcs using 63 instead of 66 feet. That gives a trap time of .357 at 120 mph. That will trick the computer into printing a 126 mph.
I guess the timing computer has a formula or small data base the the trap time is input into and out pops a speed. Doesn't matter if its a car, rail, bike if snowmobile.
Just a little info fo thought. Sorry for further hijacking the thread.