ARM 4" Downpipe || N55 (F-Gen)

An F30 N55 Downpipe is regarded as the best hardware upgrade to get the most power from your N55-powered F3X BMW.  The stock N55 downpipe comes from the factory with a catalyst that severely restricts exhaust flow.  Upgrading your downpipe unlocks more power, improves the turbo spool, allows you to run stage 2+ tuning, and increases the exhaust note of your N55-powered BMW all at once.  An N55 downpipe upgrade is the first hardware upgrade every N55 owner should invest in.

The ARM N55 Catless Downpipe is built with mandrel bent SS304 stainless steel and backed by the ARM Motorsports Lifetime Warranty.  The ARM N55 Downpipe starts with a 4" diameter at the precision CNC machined turbo v-band connection and gradually reduces to a flared joint to optimize exhaust flow while matching up to the stock mid-pipe v-band connection perfectly.    

The ARM N55 Downpipe features two O2 sensor bungs to allow for reinstallation of the OEM oxygen sensors.  The O2 sensor bungs are located higher up on the ARM downpipe to avoid stretching the O2 sensor wires during installation.  A tune or CEL Delete will be required to avoid a check engine light from displaying on instrument panel.

In addition to helping your N55 make more power and torque, it significantly improves the exhaust sound.  While the downpipe only accounts for approximately 20% of the entire exhaust system, upgrading it will produce a noticeable increase in volume, especially under full throttle and on cold starts.  If you're looking for a more extreme sound, you can pair the ARM downpipe will a full exhaust.  The ARM N55 downpipe is compatible with any aftermarket exhaust that can connect to the stock N55 downpipe.

Included:

• ARM N55 Downpipe