FOR CLOSED COURSE COMPETITION USE ONLY. NOT INTENDED FOR STREET USE.

The Factory 4.1 RCT incorporates the latest in FMF Resonance Chamber Technology™ both internally and externally. It starts at the center with a new core - a patent pending shape enhances and refines the exhaust pressure wave for optimal power output while lowering the sound level. In addition, we achieve a shorter overall length that is less susceptible to crash damage and complementary to our Factory Forward Engineering - moving the muffler closer to the motor to centralize mass. Visible changes to the exterior include a redesigned canister to increase internal capacity for the maximum volume of packing material. The packing itself was not overlooked – a proprietary blend formulated for superior durability and sound attenuation. The final component is a new rear endcap engineered for simple tuning adjustments incorporating a snap ring feature to secure the standard and optional inserts. The Factory 4.1 RCT is constructed from only aerospace grade materials that meet our exacting specifications and is manufactured 100% at our Southern California factory.

- Available in Natural or Anodized Titanium muffler
- Massive Power gains throughout the RPM range.
- Quieter than stock
- Huge weight savings
- New RTS (Rapid Tuning System) makes for easy sound insert changes as well as adding US Forestry Approved Spark Arrestor.
- FMF uses the highest quality proprietary blend of alloy titanium made especially to our standards.
- Can be used with FMF header or stock.
- #1 Exhaust in 2011 Supercross Series, 2011 Motocross Series, 2011 Motocross of Nations and 2011 Monster Energy Cup!