Lots of myth out there VS a few empirical facts. there's the SJ 1150 'big bore' kit of course, and SJ is SUPPOSED to do good headwork. RD had pics here a while of his buddy's headwork done by someone else; I took those pics and phochopped pics of MY ports over the original pics to see the 'delta' (difference) then ported 'em (on the bike!!!..how hack is that??) to match. I can say the intake boot/intake port interface was WAY off and very ugly from a flow point of view (I've been carving on 2 and 4 stroke ports for a bunch of years, just like you carve on teeth..in fact, I discuss porting tools with MY dentist). Shovelstroked said it best when he commented on my infantile desire to make a S into a horsepower king: 'spit-shining a turd'...as a 20% power increase without super or turbo charging is HARD to do.
Big power from these, like dragging big power out of a porsche 911, costs big bucks. These engines are pretty efficient, actually, right from the factory. Fix the intake and exhaust restrictions and just twist the throttle a little harder...nothing short of a K1200S will catch that ZX10 on a straight, but you CAN get 'em in the turns
