У вашего броузера проблема в совместимости с HTML5
Unlike Top Fuelers and Funny Cars, Pro Stock cars require you to use a line lock button to lock the front brakes in preparation for launching off the start line (rather than just holding down the brake button). Then you have to go through five gears, which obviously can make the chances of over-reving the engine a little bit higher if you are too slow with your gear changing.