The Slip-On Racesystem provides even greater power and unburdens weight from the rear, offering better handling. The Slip-On Race system, made of our proprietarytitanium, includes side mufflers, a link pipe set with integrated exhaust valves, an X-pipe, and four exquisite tailpipes. Add a Slip-On Race system for even greater power and sound delivery, and the reduction in weight behind the rear axle markedly improves handling. The 911 with the Slip-On Race system is noticeably more powerful, especially in the middle rev range. Theperformance exhaustsystem boasts an optional Akrapovic sound kit for exhaust valve control, which offers a choice between a sportier loud sound and regular performance, suitable for everyday driving. When installing Akrapovič aftermarket optional down pipes with sports catalytic converters or without catalytic converters, which are developed for use on closed tracks only, remapping the ECU is mandatory. When installing Akrapovič aftermarket exhaust system that was developed for use on closed tracks, we recommend remapping the ECU in order to prevent potential »check engine light« warning signals. Shown performance data are measured on a car with manual transmission.