The Straightline Performance Performance Header for 2017-current Arctic Cat Thundercat 9000 and Yamaha Sidewinder/SRX 998 Turbo delivers a proven 15 horsepower gain, increased torque, and dramatically faster turbo spool. Manufactured from premium stainless steel, this direct bolt-on header retains all factory heat shields for excellent heat management and OEM-style fit. It works exceptionally well with aftermarket ECU tunes, intake systems, clutch kits, and other performance upgrades, making it one of the best foundation modifications for any 998 turbo engine.