ARM Motorsports' N63R downpipes for the 4.4L V8 Twin-Turbo powered M550i allows you to take your N63R engine to the next level. Made with full 304 Stainless Steel and 3" construction these downpipes open up an incredible sound from the twin turbocharged V8 even with the stock exhaust!
 
By replacing the OEM downpipes with the ARM N63R Catless Downpipes, you'll be removing the restriction from the OEM converters which 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 M550i. 

You can use discount coupon code "M3List" to save on the entire Midwest Bimmer Supply website at checkout!