Get the precision and peace of mind required to take your build to the next level

Ferrea also offers precision CNC-machined retainers

1/8" NPT threaded port is required for installing

Recommendation: For those pushing their S55 to the absolute limits

BMW F1X M5 / M5 S63 Downpipes Alpina B5 Get the precision and peaceUpgrade your BMWs performance with RK Autowerks Catless Race Downpipes for the F10 M5 and F06 F12 F13 M6 equipped with the S63 engine. Designed to eliminate the restrictive factory catalytic converters, these downpipes dramatically reduce backpressure and allow your turbos to spool faster for sharper throttle response and immediate gains in horsepower and torque. Each set is engineered using advanced 3D scanning and prototyping technology to ensure