speed makes aeros much better IMO, but, as everyone has said, theese things arnt speed machines. go the west route, with the pipe. ive got one andits far far powerfuller than my irvine 53 on standard exaust. on bekra 10% fuel im turnng a 13x4w at 13,000rpm (1000rpm more than they quote). i didnt like it so i switched to the 13x4 sport. much beter IMO and far cheeper