These fins(made by CFM) are designed to direct air to your headers and top end. Like someone else said, they don't do that much for a liquid-cooled engine. I have these installed on my raptor 700, along with two CFM inline coolant coolers, and a CFM oversized oil tank, and a PWR oversized radiator. I'm sure that any one of these items installed by themselves wouldn't make that much of a noticable difference, but all-together they make my raptor run cooool as SHIT!! 8) And anyone here will tell you, a COOLER running engine will make more HP. :thumbsup: