Trail mod Firecats one F7, one F8 best stock muffler performance

designed for high altitude riding, this system is quite happy on a bone stock CTEC 800 here at 1000

Cat 800 & TCat, Polaris 650 Patriot, SkiDoo E-TEC 600 & 850, Ace Turbo

RPM, torque, BMEP, IntakeAirVelocity, 2cycleVS4cycle, portTimingVSvalves&camTiming, BoreVSstroke,