3" Catless Downpipes for N63/N63TU 4.4L V8 Twin-Turbo

The ARM N63DP 3" Catless Downpipes are engineered to significantly enhance the performance and auditory experience of your BMW 550i, 650i, and 750i models featuring the N63 or N63TU 4.4L V8 Twin-Turbo engine. By replacing the restrictive OEM catted downpipes, these catless units allow for improved exhaust gas flow, leading to notable gains in horsepower and torque throughout the RPM range. Dyno testing on a 2012 550i with a Stage 2 tune showed gains of 48whp and 43wtq after installation, resulting in a total of 460awhp and 525awtq. Constructed from full 304 stainless steel, these downpipes are designed to follow the factory exhaust flow path with minor modifications for easier installation, ensuring they mount with precision to the turbos and midpipes. Key design elements include a flex section to absorb stress from engine movement and a lower bracket secured to the transmission housing, mirroring BMW's factory mounting points for a robust connection. Two O2 sensor bungs are incorporated on each downpipe, allowing for the reinstallation of factory sensors in their original positions, which is crucial for proper DME monitoring and maintaining smooth engine operation. The package includes the ARM N63 3" Catless Downpipes, ARM Crush Brackets, and a hardware kit. These downpipes are compatible with vehicles listed in the fitment guide that feature a slip-fit style OEM downpipe connection. It is crucial to visually inspect the connection point between the downpipe and mid-pipe to confirm compatibility. For European N63 owners, these downpipes will not fit vehicles equipped with OPF (Otto Particulate Filter); these are identifiable by large filter canisters near the turbos or by checking the VIN build sheet for Euro 6c/6d emissions. This product is intended for Off-Road Use Only and is illegal to use on public roads in most jurisdictions.