F8X S55 Downpipes

ARM Motorsports SKU: SQ6319673


Available Now!


• Up to +30whp / 30wtq
• Enhanced Exhaust Note
• 304 Stainless Steel

• Improved Turbo Spool


The ARM S55 Downpipes are the ultimate solution for improving power, throttle response, and exhaust note on your S55 powered BMW. Our goal for the ARM S55 Downpipes was to provide a solution that would maximize power and torque, fit perfectly, and sound extraordinary.

Catless downpipes are considered a standard upgrade for any F8X M3/M4 owner looking to safely push their S55 engine beyond basic Stage 1 tuning. With Stage 2 and up tuning, higher boost increases back-pressure at the OEM catalysts and chokes the S55's turbochargers, causing them to work harder and shortening their life.
The ARM F8X M3/M4 Downpipes relieve the stressful back-pressure caused by high-boost tunes, allowing the exhaust to flow freely, increasing power and torque, all while extending the longevity of your S55's turbochargers. On our test car, after installing our F8X downpipes and switching to a Stage 2 flash we made 539whp/544wtq, this is 68whp and a massive 127wtq gain over just the Stage 1 flash! Even with the Resonated ARM F8X M3/M4 Downpipes installed on your stock-tune S55, you will notice an increase in power, torque and responsiveness. Not to mention the incredible, head-turning sounds your M4 will make under part and full throttle.


The ARM Resonated S55 Downpipes give your F8X M3/M4 an unparalleled sound that even other M2/M3/M4 owners will notice. The deep, aggressive tone of the ARM F8X M2/M3/M4 Resonated Downpipes will stand out next to the all too familiar high-pitched rasp of other catless downpipes. Our 4" resonators are installed in the perfect location to enhance the sound of your S55 without compromising the precise fitment of our M3/M4 downpipes.


Precision CNC machined v-band flanges offer a smooth transition of exhaust gasses from the the turbochargers to the ARM S55 Downpipes. The body of the 3" ARM M3/M4 Downpipes are constructed of SS304 Stainless-Steel and are threaded smoothly and perfectly though the space given by BMW towards the mid-pipe section.

Any downpipes that bolt up directly to the OEM mid-pipes must reduce to the 2.5" to meet the size of the OEM mid-pipes. Some aftermarket downpipes use an abrupt, short reducer which causes turbulence in the exhaust gasses. The ARM F8X M2/M3/M4 Downpipes feature a smooth, gradual transition from the 3" inlet to the 2.5" exit for optimum exhaust flow.

The ARM M4 Downpipes are a massive improvement over the OEM S55 downpipes, with precise fitment and brilliant finish the ARM S55 Resonated Downpipes are the perfect solution for your S55 project. Our goal for the ARM F8X M2/M3M4 Downpipes was to provide a solution that would maximize power/torque, fit perfectly, and sound uniquely extraordinary. We are so confident that you'll agree we've achieved this, we back every set of our ARM F8X M2/M3/M4 Resonated Downpipes with a 30 Day Money-Back Guarantee and the ARM Lifetime Free-Replacement Warranty.


• ARM F8X M2/M3/M4 Resonated Downpipes
• CNC Machined Bracket for Front-Turbo Downpipe
• 4x Downpipe to Mid-Pipe Bolts/Nuts
• ARM Lifetime Replacement Warranty