I have thunderbike pipes which i *think* are probablt as open as any other unless of course they removed thier baffles. 130's made no difference in my bike over the stock 120's except in the bike's demeaner. In other words, they made it feel a little smoother and the sound changed slightly. But no poer diff. While needle changes has netted me significany increase in power. So that led me to thyink maybe i need richer mains. But i was hoping someone would be able to tell me how high i likely could go before seeing negitive resluts. if he went to 160's w/o an airbox removal kit i just cant help but think i should be able to go to at least 140's and that maybe then i WOULD see an increase in wot situations. But i hate buying jets w/o knowing because they get expensive with shipping if they end up being put on the shelf.
