The Evolution Racewerks Sports Series 4" High Flow Catted Downpipe is engineered to dramatically reduce backpressure and improve turbocharger efficiency on the BMW N20 four-cylinder engine. The factory downpipe uses a restrictive 400-cell ceramic catalyst that slows exhaust flow and increases turbulence. By replacing it with a high-flow 200-cell metallic core, this system unleashes horsepower, improves throttle response, and reduces turbo lag.

Built from 100% 304 stainless steel, the downpipe features mandrel-bent 4" tubing, precision CNC-machined flanges, and full TIG welds for maximum strength and long-term reliability. A stainless flex section is incorporated to match factory movement and prevent stress on the turbo and exhaust system—a critical feature many competitors skip.

The improved long-transition design allows exhaust gases to move smoothly from the turbocharger to the factory or aftermarket exhaust, reducing turbulence and maintaining higher exhaust velocities. Optional ceramic thermal coating helps control underhood temperatures while further improving flow efficiency. Additional O2 and EGT bung options are available for custom tuning setups.

Key Features:
• High-flow 200-cell metallic catalytic converter
• Increased horsepower and torque with faster turbo spool
• Significantly improved throttle response
• Mandrel-bent 4" stainless steel piping
• CNC-machined turbo V-band flange
• Stainless flex section for correct exhaust movement
• Fully TIG-welded 304 stainless steel construction
• Optional ceramic thermal coating
• Optional O2 and EGT sensor bungs
• Compatible with factory and aftermarket exhausts
• Includes all installation hardware
• Limited Lifetime Warranty

Fitment 

Compatible With N20 Engine (Not Compatible With N26):

• 2012 BMW 320i
• 2013 BMW 320i
• 2014 BMW 320i
• 2015 BMW 320i

• 2012 BMW 328i
• 2013 BMW 328i
• 2014 BMW 328i
• 2015 BMW 328i

• 2012 BMW 420i
• 2013 BMW 420i
• 2014 BMW 420i
• 2015 BMW 420i

• 2012 BMW 428i
• 2013 BMW 428i
• 2014 BMW 428i
• 2015 BMW 428i

This system is track-tested for durability and comes complete with all required installation hardware along with a Limited Lifetime Warranty.