FMF

The FMF Factory 4.1 RCT Slip-On Muffler is built to deliver strong power gains with controlled sound levels for motocross and enduro. RCT (Resonance Chamber Technology) improves exhaust flow while meeting AMA/FIM sound requirements.

• RCT patented core design lowers decibels while maintaining maximum power
• QuietCore 94 dB insert included + spark arrestor integrated
• Lightweight titanium canister with carbon-fiber end cap (Made in USA)

The FMF Factory 4.1 RCT Slip-On Muffler is built to boost off-road performance with Resonance Chamber Technology™ and a compact, crash-resistant design that moves weight closer to the engine. Made from aerospace-grade materials and manufactured in Southern California for race-ready durability.

• ✅ RCT Resonance Chamber Technology™ (internal & external)
• ✅ Shorter length helps reduce crash damage and centralizes mass
• ✅ Aluminum canister, carbon-fiber end cap, stainless-steel pipe

FMF Factory 4.1 RCT Slip-On Muffler is a premium race-focused exhaust upgrade built to boost performance with FMF Resonance Chamber Technology™ and a compact, mass-centralized design. Made from aerospace-grade materials for high strength and low weight.

• Titanium muffler and titanium pipe for lightweight durability
• Carbon fiber end cap with black finish
• Shorter length to reduce crash damage and move mass closer to the engine

FMF Factory 4.1 RCT is a high-performance slip-on muffler built to deliver massive power gains across the RPM range while cutting weight. Its shorter, factory-forward design helps centralize mass and reduce crash damage.

• RCT (Resonance Chamber Technology) internally & externally
• RTS (Rapid Tuning System) for fast setup changes
• Aerospace-grade aluminum/stainless construction with carbon end cap

FMF Factory 4.1 RCT Slip-On Muffler is built to deliver massive power gains across the RPM range while cutting weight for sharper handling. Its shorter Factory Forward design helps protect the exhaust in crashes and centralizes mass for better balance.

• Resonance Chamber Technology™ (RCT) for strong, broad power
• Shorter overall length to reduce crash damage & improve mass centralization
• RTS (Rapid Tuning System) + premium materials (carbon/stainless/aluminum)

FMF Factory 4.1 RCT is a high-performance slip-on muffler built to boost power across the RPM range while cutting weight. Its compact design helps reduce crash exposure and centralizes mass by positioning the muffler closer to the engine.

• RCT (Resonance Chamber Technology) for strong, usable power gains
• RTS (Rapid Tuning System) for quick, easy tuning changes
• Aerospace-grade build: aluminum canister, stainless pipe, carbon fiber end cap