Is there such a thing?I thought thats what the throttle was for.I'm running an Emaxx 3905.But I'm really planning on revo.I don't really plan on 6s all the time.I'm afraid any lower kv won't perform to good on 4s.I'm a little bit spoiled on power.Until I got my maxx on wednesday I usually drove my Stampede with novak hv4.5 and 3s lipo.I was totally unable to hit full throttle. :) I don't really want that much power to weight in a big truck .Right now I have my 4.5 in my maxx,but it just isn't quite enough.Though it did hit 41mph and stays pretty cool.Under 150.