KYOSTAR Catless Downpipe for 2019+ Audi C8 RS6 RS7 EA825 4.0T V8 Mild Hybrid Upgrade your 2019+ Audi C8 RS6 or C8 RS7 equipped with the EA825 4.0T twin-turbo V8 Mild Hybrid quattro system with the KYOSTAR Catless Downpipe. Designed as a performance-oriented replacement for the factory downpipe configuration, this system provides an upgraded exhaust flow path for high-performance Audi RS applications. The catless downpipe design removes the catalytic converter section from the