Capitalising on the design innovations and success of our 996 and 997 range, the starting point for designing the 991 Carrera exhaust had been set high. Our trademark perfect x pipe geometry, harmonically tuned silencer geomtery, Inconel 625, and our proprietry acoustic silencer packing materials result in a system that has become famous for that perfect sound. Zero drone, and a raised pitch raucious incindiary howl in higher rpms and hard throttle

The x pipe geometry, designed to give a particular tone, a tone which has become synonymous with all kline systems as they all share the same relative geometry. This geometry within the x pipe is the result of a lot of R&D work specifically around tonal quality of exhaust notes (and I know it just looks like a simple x pipe) but minor changes in its geometry vastly effect exactly how the gas resonates at varying rev regions and gas throughput, and therefore have a pretty big impact on the sound.