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.
* Delivers huge power at a very light weight
* Offers better handling thanks to a lower centralized mass coefficient
* Uniquely-styled pentagonal muffler body with a carbon fiber cone end cap
* Front cap design functions as a polyresonant chamber to lower dB output while improving mid- to top-end power
* Two-staged, stepped baffle
* Tapered headpipe delivers optimal flow and performance
* Systems come with 96 dB insert installed (meets AMA competition requirements), 2 meter Max insert in the box
* System features stainless steel header pipe and satin-finish aluminum muffler sleeve
![Yoshimura RS-4 Signature Slip-On Exhaust for 450 SX 16 Yoshimura RS-4 Signature Slip-On Exhaust for 450 SX 16](https://cdn11.bigcommerce.com/s-3p5jv3j67w/images/stencil/120x160/products/136717/327927/1821-17652-250__62448.1688707289.jpg?c=1)