PROFILE

The ARM BMW 335i 3.5″ Resonated Midpipe replaces the restrictive factory dual midpipes with a single, high-flow 3.5″ design engineered to improve exhaust efficiency while delivering a deeper, smoother exhaust note. By merging the exhaust flow into a single, 3.5″ midpipe, backpressure is reduced and overall exhaust flow is improved. The factory BMW 335i midpipe uses a dual midpipe design which incorporates secondary catalysts which prioritizes noise control and mass production over performance and sound quality. While effective for daily driving, the OEM setup creates unnecessary restriction and limits exhaust flow as power levels increase.

The ARM 335i 3.5″ Single Midpipe is designed to connect directly to the factory axle-back section, allowing full retention of the OEM exhaust valve controllers and factory valve operation. This maintains OEM drivability and comfort in normal driving conditions while unlocking a more aggressive and engaging sound under throttle.  The ARM 335i 3.5″ Resonated Single Midpipe prioritizes exhaust note and performance. The integrated resonator is carefully sized and positioned to reduce rasp and harsh frequencies commonly associated with straight-through midpipes, especially on N54 and N55 platforms.

CONSTRUCTION

The ARM 335i 3.5″ Single Midpipe begins with a dual 2-bolt flange design which allows you to connect it with any downpipes that mate up to the OEM 335i midpipe.  This allows the midpipe to bolt directly to any downpipes that are designed to mate to the OEM 335i midpipe, including factory downpipes as well as most aftermarket downpipes that retain the OEM-style 2-bolt outlet configuration.  

It then transitions smoothly to the 3.5″ single midpipe section.  This section incorporates a single resonator to deepen and improve the exhaust note by reducing rasp and high-pitched tones. The resonator is designed to attenuate high-frequency and raspy exhaust notes commonly associated with turbocharged BMW engines, while preserving a deep, aggressive tone under acceleration. The result is a smoother, more controlled exhaust sound without introducing excessive restriction or drone. 

Towards the rear section of the ARM 335i 3.5″ Midpipe splits back to a dual design to connect with the OEM axle-back exhaust section. By retaining the factory dual outlet layout at the rear, the ARM midpipe preserves full compatibility with the OEM axle-back and its integrated exhaust valve system. This ensures proper exhaust flow distribution, correct valve operation, and OEM-level fitment, while maintaining the performance and sound benefits of the single 3.5″ midpipe design throughout the center section.

To allow for clearance of the OEM chassis brace, the ARM 335i 3.5″ Resonated Midpipe includes two precision machined aluminum chassis brace spacers which allow extra space for the larger 3.5″ ARM Midpipe to pass through to the axle-back section. This solution allows the larger midpipe to pass through without contact or vibration while retaining the factory chassis brace and its structural function. The spacers are designed specifically for correct fitment and alignment, ensuring a clean installation without cutting, bending, or permanent modification to the vehicle.

FITMENT GUIDE

This product is for Off-Road Use Only. Items sold for off-road use only are illegal to use on public roads in most states and provinces. This product is intended for racing vehicles which may never be used on a public road.