ARM Motorsports N55 CATTED DOWNPIPE - F3X - 4" EWG - N55EWG-C

Upgrade your BMW N55-powered F-Series with the ARM Motorsports N55 Catted Downpipe – 4-Inch EWG, designed to improve exhaust flow, enhance turbocharger response, increase exhaust sound, and support upgraded engine tuning. Featuring a high-flow 200-cell sport catalytic converter and premium SS304 stainless steel construction, this performance downpipe delivers the benefits of an aftermarket downpipe while helping reduce exhaust odor compared with a catless downpipe.

Key Features and Benefits

• Power Gains: Potential gains of up to 23 wheel horsepower (whp) and 29 wheel torque (wtq).

• Faster Turbo Spool: Improved exhaust flow helps the turbocharger spool faster.

• Enhanced Exhaust Sound: Increases exhaust volume and makes turbo spool and exhaust burbles more noticeable.

• Tuning Compatibility: Supports Stage 2 and Stage 2+ tuning applications that require an upgraded downpipe.

• High-Flow Catalytic Converter: Features a 5-inch, 200-cell sport catalytic converter to improve exhaust flow while retaining a catalytic element.

• Premium Construction: Manufactured from mandrel-bent SS304 stainless steel.

• Precision Turbo Connection: Starts with a 4-inch diameter at the CNC-machined turbo V-band connection.

• OEM Midpipe Compatibility: Transitions to a flared joint designed to connect to the factory midpipe V-band connection.

• Oxygen Sensor Compatibility: Includes two O2 sensor bungs for reinstalling the original oxygen sensors.

• Optimized Sensor Placement: The O2 sensor bungs are positioned higher on the downpipe to help prevent stretching the oxygen sensor wiring during installation.

• Warranty: Backed by the ARM Motorsports Lifetime Warranty against defects in craftsmanship or fitment.

Performance and Power Improvements

The factory BMW N55 downpipe contains a catalytic converter that restricts exhaust flow. Replacing it with the ARM Motorsports N55 Catted Downpipe helps reduce exhaust restriction, improve turbocharger response, and support increased power and torque when paired with appropriate engine tuning and supporting modifications.

The manufacturer advertises potential gains of up to 23 whp and 29 wtq. Actual results depend on the vehicle's configuration, engine condition, tuning software, fuel, and supporting modifications.

Enhanced N55 Exhaust Sound

The ARM Motorsports N55 4-Inch Catted Downpipe increases overall exhaust volume, particularly during cold starts and under full throttle. It can also make turbocharger spool more audible and enhance exhaust burbles, including on vehicles running the original BMW engine control programming.

The downpipe can be installed with the factory exhaust system or paired with a compatible aftermarket exhaust for a more pronounced sound. It is compatible with aftermarket exhaust systems designed to connect to the factory N55 downpipe.

High-Flow Construction and Design

The ARM Motorsports N55 Catted Downpipe is constructed from mandrel-bent SS304 stainless steel for durability and consistent exhaust flow. Its design begins with a 4-inch diameter at the precision CNC-machined turbocharger V-band connection, transitions into a 5-inch, 200-cell sport catalytic converter, and gradually reduces to a flared joint that matches the factory midpipe V-band connection.

Two oxygen sensor bungs allow the original O2 sensors to be reinstalled. Their elevated positioning helps avoid excessive stretching of the sensor wiring during installation.

Important Tuning Note: A suitable ECU tune or CEL-delete solution may be required to prevent the check engine light (CEL) from illuminating after installation. Confirm compatibility with your vehicle and tuning software before purchasing.

Stage 2 and Stage 2+ Tuning Compatibility

The ARM Motorsports N55 Catted Downpipe is designed to support F-Series BMW N55 tuning applications that require an upgraded downpipe. Improved exhaust flow helps prepare the vehicle for higher-boost tuning when used with the appropriate software and supporting hardware.

Many Stage 2 tuning setups require both an upgraded downpipe and a front-mount intercooler (FMIC). Confirm your tuning provider's hardware requirements before installation. The manufacturer notes that properly configured Stage 2 N55 applications can reach approximately 400 whp and 400 wtq; actual results will vary according to the setup.

What's Included

• One ARM Motorsports N55 Catted Downpipe

Vehicle Fitment

This downpipe is designed exclusively for the vehicles listed below equipped with the N55 3.0L engine and a 4-inch EWG turbocharger. Verify the turbocharger configuration before ordering.

ARM Motorsports Lifetime Warranty

Every ARM Motorsports product is backed by a lifetime warranty, automatically issued at the time of purchase. The warranty covers defects in craftsmanship or fitment and entitles the purchaser to a replacement unit in accordance with the manufacturer's warranty terms.

Intended Use

Off-Road Use Only. This product is intended for racing vehicles that may never be used on public roads. Products designated for off-road use only may be prohibited on public roads under applicable state, provincial, or local laws. Verify applicable emissions regulations and legal requirements before purchasing or installing this product.