Staging in Stock Elim

[201250]

While watching some of the incar videos of the automtaic stock elim. cars, I noticed they seem to be pumping the brakes and bumping it into the stage beam. I know you can't use transbrakes so that only leaves a linelock and 2-step. So you have 2 switches one for just the line lock and another for linelock & 2-step. Determine what RPM that will alow you to go full throttle without the car moving or are they using pressure gauges to get consistant pressure (pumping brakes)