ok, ive seen diagram after diagram, but i still have not a clue what it is. Can someone tell me what the thing does? BTW the 1st time i had ever heard of it was on Duc's 700hp dyno video. Why does his sound like a shotgun?

Thanks

 

the 2 step is killing the igntion randomly to keeps rpms in check.

All it is, is a revlimiter.