E-SERIES N55 DOWNPIPE

The ARM E-Series N55 Downpipe increases power on your N55-powered BMW by optimising exhaust flow and reducing back-pressure. It's the first hardware upgrade every N55 owner should make — unlocking power, improving turbo spool and enabling Stage 2+ tuning, all while making your 135i or 335i sound better. Compatible with OEM and aftermarket midpipes via an 80mm V-band flange that fits standard and upgraded turbos.

Highlights

• Gains of up to 21 whp / 27 wtq.
• Faster turbo spool and improved exhaust sound.
• Enables Stage 2+ tuning.
• SS304 stainless steel.

Construction

TIG-welded SS304 starting with a precision CNC-machined 80mm V-band flange (fits the OEM N55 turbo and many upgrades) welded to a flex section to relieve turbo stress. A distinctive 4.5" middle section produces a deeper, more aggressive note than a standard 3" downpipe, then transitions to dual 2.5" flanges to integrate with OEM and aftermarket midpipes. Two O2 sensor bungs, located higher up, avoid stretching the sensor wires.

Fitment (N55 3.0L)

BMW E82 135i, E81 135i Convertible, E90 335i & 335i xDrive, E92 335i & 335i xDrive, E93 335i & 335i xDrive.

What's included: ARM N55 downpipe, 2x midpipe gaskets, 4x bolts/washers/nuts.

Backed by ARM Motorsports' lifetime warranty against defects in craftsmanship and fitment.

Emissions disclaimer: This product is intended for off-road, race, or closed-course competition use only and is not legal for use on pollution-controlled vehicles operated on public roads in most states and provinces. You are responsible for compliance with all applicable emissions laws. Please check your local laws before purchase and installation.

Ships from our Vancouver shop — KORE SPEED is proudly Canadian-owned, with no surprise cross-border duties for Canadian buyers. Questions on fitment? Email support@korespeed.com.