My buddy got the solas impeller and we raced I have free flow exhaust and removed the flame arrestor (not really performance mods in my opinion) and we were dead tied, we did race a stock spark at the same time and were just a little bit faster, so far I am not sold on the impeller due to these results. However I will still be purchasing one to see how much I can gain from it as well as reducing cavitation and corrosion as the stock one is already heavily corroded after only 14 hours.