yea, i forgot how my old rev limiter worked, mine killed the engine till i dropped back down to 10500rpms. (didn't have any power). i like ronv's idea. add a pot for adjustments for your main tire runout adj. and even add a fine adj for differing track conditions.
ps. one drawback to this idea would be if your car lifts the front wheels?? if that happens, you would be hindering your times, then a sensor override
in the front suspension would be the next item.