RPM Pro R “Big Core HeadPipe” Head Pipe

Often hated is the Pro R’s “out of frame” head pipe. Make no mistake this is the most efficient head pipe design for this engine and we wont bore you with information in regard to gas wave propagation, cylinder overlap timing, gas particle flow, and proper exhaust pressure waves. Let’s just say Polaris had help designing the head pipe the way it is, and there wasnt a lack of R&D.  Does this mean it’s perfect? No. Polaris mass produces these and naturally the head pipe has “mass production” flaws. Furthermore the OEM head pipe is designed and built for a stock machine with a stock restrictive muffler. Polaris simply did what they could, with what they had.

First less start with saying the RPM Big Core HeapPipe is a direct bolt on head pipe that retains the stock heat shield and can even bolt to the factory muffler ( or any aftermarket muffler that will bolt to a factory head pipe ). The RPM Big Core HeadPipe has a smoother than stock flowing inner core with less restrictive interior design than that of the OEM head pipe. This was achieved by not only slightly increasing the manifold size to better port match the gasket and cylinder head ports but also the size of the 4 “smaller pipes” after the manifold.  The 2 “medium sized” pipes are also increased in diameter, but decreased in length almost completely by eliminating the 2-1 factory section & incorporating it into the unique 4-2-1 collectors. With the decrease in the 2″ section of the 2-1 RPM has drastically increased the 3″ sections length while allowing it to make a smooth bend around the frame rail towards the muffler. The 3″ section is much closer to the frame rail allowing for less exhaust pipe exposed and creating more tire clearance. In addition to the factory O2 sensor retaining its stock location, next to it is an added O2 bung for those with an added O2 monitor or data logger. All of this happens between the 10mm thick header flange, and OEM replicated muffler flange! Each head pipe includes new kit of grade 8 allen head hardware & gaskets are optional at a discounted price!