ok here we go ,here in phila we we were told by our good friends at star cycle that the best horsepower gains were from muzzy unless you went to brokton racing & ordered 1 of their race pipes but that is all your going to do wtih this pipe is race it is not designed for street riding ,so muzzy beleive it or not has better horsepower gains than the akaropovic pipe ,if power is what you crave than iys muzzy