PROFILE

The ARM Motorsports N20 Downpipe is the best hardware upgrade to get the most power from your 320i or 328i.  The N20 has a stock downpipe with a catalyst that drastically restricts exhaust flow.  This limits not only the amount of power N20 can make on the stock tune, but also prevents upgrading to a stage 2 tune due to excessive back-pressure.  An N20 downpipe upgrade is the first hardware upgrade every N20 owner should invest in.  Upgrading your downpipe unlocks the most power, increases turbo spool, allows you to run stage 2+ tuning, and improves the exhaust note of your N20 powered BMW. 

CONSTRUCTION

The ARM N20 Catless Downpipe is built with mandrel bent SS304 stainless steel and backed by the ARM Motorsports Lifetime Warranty.  The ARM N20 Downpipe starts with a 4" diameter at the precision CNC machined turbo v-band connection and gradually reduces to a 2.5" diameter to optimize exhaust flow while matching up to the stock mid-pipe.  The ARM N20 Downpipe also features two mounting points to reduce tension on the turbo from shifting and twisting during aggressive driving.  

The ARM N20 Downpipe features two O2 sensor bungs to allow for reinstallation of the OEM oxygen sensors.  An tune or CEL Delete will be required to avoid a check engine light from displaying on instrument panel.

 By reducing the back-pressure on your turbocharger, the ARM N20 Downpipe prepares your 320i / 328i for higher boost tunes. Testing on our 328i with only a Stage 1 tune yielded a very respectable 17whp and 25wtq gain.  While switching to a Stage 2 tune gave it an additional 13whp and 12wtq, a total gain of 30whp and 38wtq over Stage 1 alone.

In addition to helping your N20 make more power and torque, it also opens up the otherwise tame exhaust note.  If you're running a stock midpipe and catback section you'll notice a substantial increase in volume under full throttle and a moderate increase in sound during part throttle.  Coupled with a midpipe or full exhaust your N20 can sound quite impressive.  The ARM N20 Downpipe connects to any aftermarket exhaust that is compatible with the stock N20 downpipe.

All ARM Motorsports Products are backed by a 30 Day Guarantee and ARM Limited Lifetime Warranty.  

IN THE BOX

FITMENT GUIDE

Some models will require the stock midpipe to be expanded a few millimeters to accommodate the upgraded downpipe.