I would have to disagree with your comments about the beams at the drag strip. the beams at the strip at triggered by your front wheels, when you stage the vehicle and bring on the two bulbs on the christmas tree you are breaking the beam, as soon as you roll forward a fraction the beam breaks and the timing sequence starts, any difference in staging ie deep staging or short staging will only effect the et by a very small margin, around 0.001-5 of a second not a couple of tenths.