Fastest quad ever stock was the quadracer 500 Suzuki then the rest ! But I think that renegade /thundarcat are the straightline fastest stock the 450,s can be made faster/easly compared to them 450,s are track/trail racers compared to those two stump pullers . When it comes to track/trail they,ll get spanked ! in straight line there 800cc-1000cc monsters going ahead to head with a 450 is almost double the cc,s it should win !