I need some help figuring out how some guys at our local track are cheating. I thought maybe you guys could help..... I hope!!

I'm talking Pro, Heavy, Non electric CLASS
Whenever this certain group of guys stage at the tree they automatically go to there max RPM and there is no fluxuation in the rpms at all. No sound of the engine going to their preferred rpm. It just immedatially is like they have it to the floor. Their lights are normally all 00's and these guys aren't this consistent. What could it be? Please help if you have any insight.