HIGHLIGHTS

PROFILE

ARM Motorsports new N63/N63TU Catted Downpipes for the 4.4L V8 Twin-Turbo powered 550i allows you to take your N63/N63TU engine to the next level. Designed with the same precision as our N63 Catless Downpipes, the ARM N63 Catted Downpipes feature high-flow 200 cell ceramic sport catalytic converters positioned in the OEM location. 

Made with full 304 Stainless Steel and 3″ construction these downpipes provide a significant increase in power and torque over the OEM catted downpipes. In addition to the massive power gains, these downpipes open up an incredible exhaust sound from the turbocharged V8!

 
By replacing the OEM downpipes with the ARM N63 Catted Downpipes, you’ll be removing the restriction from the OEM converters.  This will reduce exhaust back-pressure and allow the exhaust from the turbochargers to flow more freely. This increase in exhaust flow allows for the turbos to spool faster, increasing power and torque throughout the RPM range of your N63. 

DYNO PROVEN

Tested on an N63-powered 2012 550i GT xDrive with a Stage 2 tune, the addition of ARM’s 3″ Downpipes and Cold Air Intake yielded +48whp and +43wtq, raising output to 460awhp and 525awtq. The catted version maintains nearly identical gains compared to the catless setup, while offering the benefits of a catted exhaust system.

CONSTRUCTION

Like all BMW performance components, precision fitment is critical. The ARM N63 Catted Downpipes are engineered to follow the smoothest possible exhaust flow path while easing installation.  Consequently, the ARM N63/N63TU downpipes mount up to the turbos and midpipes with the same precision as you would expect from the factory 550i downpipes. 
 
 
The ARM N63 Catted Downpipes come with a flex section to relieve stress between the upper and lower portion of the downpipe from engine movement during aggressive driving. To further reduce any tension on the turbochargers, we have developed a lower bracket, on the lower portion below the flex joint where it is secured to the transmission housing. This is the same point BMW designed their factory N63 downpipes to be secured, which means a strong and lasting connection safe for all the components on the vehicle.
 

 
The ARM N63 Catted Downpipes utilize two O2 sensor bungs on each downpipe to allow for reinstalling the O2 sensors in their factory locations. This not only allows for the accommodation of the upper factory heat shield, but also allows the correct O2 sensor data to be sent to the DME. This is essential for the DME to properly monitor the parameters in the exhaust that are critical to having your N63 running smoothly. 

IN THE BOX

• 2x ARM N63 3″ Catted Downpipes
• 2x ARM Crush Brackets
• 1x Hardware Kit

FITMENT GUIDE

The ARM N63/TU Catless Downpipes are compatible with the cars on the list below that have a slip-fit style OEM downpipe only. The most reliable and accurate way is to simply look under your vehicle for the connection point between the downpipe and mid pipe. In most cases, this is visible without having to remove any undertrays or covers. If your connections look like the images below and your car is listed on the fitment chart, these will fit your vehicle.