The work that went into developing the RS-4 muffler design paid big
dividends in 2010 with Ryan Dungey winning the AMA 450 Supercross and
Motocross Championship series as a rookie in the same year, and again in
2012 with the Yoshimura-backed GEICO Honda team winning both 250
Supercross Lites titles.
That same R&D has been directed to
developing the current generation RS-4 — a unique design that provides
an unrivaled combination of power and a quiet exhaust note. The RS-4
features a Polyresonant duplex chamber, a two-staged stepped baffle and
an innovative carbon cone end cap.
Pentagonal-shaped sleeveFront muffler cap functions as a polyresonant chamber which helps reduce noiseTwo-stage stepped baffleCarbon fiber end-capStainless steel header and tail-pipe