N20 Downpipe

The ARM N20 Catless Downpipe is a crucial hardware upgrade for N20 engine owners looking to maximize performance. The stock downpipe significantly restricts exhaust flow, limiting power output and preventing optimal tuning. This upgraded downpipe alleviates excessive back-pressure, unlocking more power, faster turbo spool, and enabling Stage 2+ tuning. It also enhances the exhaust note. Constructed from SS304 stainless steel with mandrel-bent tubing, the ARM N20 Downpipe features a 4-inch diameter at the turbo v-band connection that tapers to 2.5 inches to match the stock mid-pipe. It includes two O2 sensor bungs to accommodate OEM sensors. A tune or CEL delete is required to prevent a check engine light. ARM Motorsports backs this downpipe with a Lifetime Warranty. Please note, this product is for Off-Road Use Only and is intended for racing vehicles. When installed on a 328i with a Stage 1 tune, testing showed gains of up to 17whp and 25wtq. With a Stage 2 tune, an additional 13whp and 12wtq were observed, for a total gain of 30whp and 38wtq over Stage 1 alone. The downpipe also noticeably increases the volume of the exhaust note under full throttle and moderately at part throttle when paired with the stock mid-pipe and cat-back section. It is designed to connect to any aftermarket exhaust compatible with the stock N20 downpipe.