ARM Motorsports BMW S55 MIDPIPE UPGRADE - 3.5" RESONATED

The ARM Motorsports 3.5" Resonated Midpipe Upgrade for the BMW F80 M3 and F82/F83 M4 dramatically enhances both exhaust flow and sound, offering one of the most effective upgrades for S55-powered vehicles. Featuring a large 3.5" resonated single-pipe design, this midpipe reduces backpressure, improves turbo spool, and delivers up to +20whp and +30wtq when paired with complementary modifications. It also transforms the tone of the S55, reducing rasp and creating a deeper, more refined exhaust note.

Precision-built from 304 stainless steel, the midpipe uses mandrel bends for uninterrupted flow and weighs only 17 lbs—cutting approximately 15 lbs compared to the OEM midpipe. When combined with the ARM S55 Track Exhaust, total exhaust weight savings can reach up to 40 lbs. The system begins with a CNC-fabricated Y-pipe that connects seamlessly to any downpipes compatible with the OEM midpipe layout, including ARM S55 Downpipes.

A 4.5" resonator is integrated to tune the exhaust into a smoother, richer tone, eliminating much of the harsh, high-pitched rasp commonly associated with the factory S55 system. The rear section transitions back into a Y-pipe that splits to dual 2.5" pipes, allowing perfect compatibility with the OEM rear muffler or aftermarket exhausts such as the ARM S55 Track Exhaust.

Because of the increased midpipe diameter, the OEM under-brace cannot be reused. To address this, the kit includes a custom 6061 aluminum under-brace engineered specifically for clearance, strength, and reduced weight. Installation is fully bolt-on and utilizes factory mounting points for a secure, precise fit.

Fitment:
• BMW F80 M3 – S55 3.0L
• BMW F82 M4 – S55 3.0L
• BMW F83 M4 – S55 3.0L