No govenor on mine.I had alot of straight away and shifted to 6th as the GTO started to get a car on me. I went by and when I had 2 cars on him he let out and I let off and looked down to my suprise 150 or real cloose as to 140 and 160 being the MPH numbered. Just let her coast down and got a thumbs up from the GTO driver as he eased by. I'm not sure what it will top out at but seemed to have more left. The engine pulls hard right up to fuel cut.