Just having larger tubes though isn't enough to make the right gains. Might gain up top but sacrifice low and middle. There's definitely a science to designing a proper tubular exhaust header for sport bike engines that delivers REAL gains across the board. The factory already has a very good header system given it also has to pass exhaust and noise emissions, as well as packaging constraints. It's not easy to outdo that because a "better" header has to also come with a good tune to take advantage of it. Akrapovich, Yoshimura, Two-Brothers, are one of those manufacturers that do their homework when they release a header system.
Last edited by OCLandspeeder; 06-14-2019 at 02:40 PM.