KYOSTAR Catless Downpipe for 2011-2017 BMW F10 M5 2012-2018 F12 F13 F06 M6 S63 4.4T V8 The KYOSTAR Catless Downpipe is designed for BMW S63 4.4T Twin Turbo V8 engines, including BMW F10 M5 and F12/F13/F06 M6 models. This performance exhaust upgrade removes the restrictive factory catalytic converter section to improve exhaust gas flow, reduce backpressure, and enhance turbocharger efficiency for high-performance BMW M applications. Manufactured from durable stainless steel