Evolution Racewerks Sport Series 4" Catted Downpipe – BMW 328i / 428i (N20, F20 / F30)

OVERVIEW

Evolution Racewerks' Sports Series 4" High Flow Catted Downpipe is built for the N20 four-cylinder turbo engine and fits 2012 and newer 320i, 328i, 420i and 428i models with that engine. It does not fit the N26 engine.

Restrictions in the exhaust system rob horsepower and torque, especially on turbocharged cars, so removing as much restriction as possible increases both significantly. The factory catalytic converter inside the stock downpipe is a major culprit: its catalyst material is formed into tight honeycomb weaves that exhaust gas must pass through, and it creates turbulence downstream that slows exhaust flow further. The factory catalyzer uses a 400 cell ceramic core, meaning 400 cells per square inch. Evolution Racewerks uses a 200 cell metallic core instead — fewer, larger cells that exhaust gas passes through more easily. Lower cell count means higher flow, which means more power, faster turbo spool and better throttle response. A metallic core also tolerates more heat, lasts longer and weighs less than the ceramic factory unit.

The downpipe is constructed from 100% 304 grade stainless steel with mandrel bent piping, 100% TIG welded by ER's in-house fabricators and built in the USA. The factory turbine housing uses a 4" V-band flange, which ER duplicated and CNC machined from billet 304 stainless. Because the ER catalytic converter is more compact than the factory unit, there is room for very long transitions between the 4" turbo outlet and the 2.5" exhaust rather than the short transitions BMW was forced to use, which reduces turbulence and backpressure. Like the factory part, the ER downpipe incorporates a 100% stainless steel flex section so the exhaust can move without putting undue stress on the turbocharger, manifold and exhaust components — something many competitors leave out.

SPECS

• Catalytic converter: high flow 200 cell metallic core
• Piping: mandrel bent 4", with long transitions down to the 2.5" factory exhaust diameter
• Construction: 100% 304 grade stainless steel, 100% TIG welded, built in the USA
• Turbocharger flange: precision CNC machined 4" V-band cut from billet 304 stainless steel
• 100% stainless steel flex section, as used on the factory downpipe, for proper exhaust movement
• O2 sensor retained in the factory location; CNC machined O2 bung and laser cut brackets TIG welded with stainless rod
• Finish: mirror polish or brushed
• Optional high temperature black thermal (ceramic) coating rated to 2000°F; available in black only
• Optional additional O2 sensor bung for a wideband O2 sensor, supplied with a pre-installed plug
• Optional EGT sensor bung for EGT gauges, supplied with a pre-installed plug
• Compatible with the factory or aftermarket exhaust systems
• Track tested durability
• All hardware for a complete installation is included
• Warranty: Evolution Racewerks Limited Lifetime Warranty

PARTS INCLUDED

• Sports Series 4" high flow 200 cell metallic catted downpipe
• All hardware required for complete installation, as supplied by Evolution Racewerks

TECH RESOURCES

Additional Parts Required

• None. Evolution Racewerks specifies no additional hardware for this part; all installation hardware is supplied and the downpipe works with the factory or an aftermarket exhaust.
• A signed Vehicle Compliance Waiver and vehicle use verification are required before this part can be sold and shipped.

Installation

• Evolution Racewerks does not publish a downloadable installation guide for this downpipe. It bolts to the factory turbocharger V-band flange and to the factory or aftermarket exhaust with the supplied hardware.
• Verify whether your car has the N20 or N26 engine before ordering — this downpipe fits N20 only. Contact Speed Logic if you need help confirming your engine.

Notes

• Does not fit the N26 engine. Fitment above follows Evolution Racewerks' published application data; confirm your chassis and engine code with Speed Logic before ordering.

PART NUMBER

• BM-EXH006SCAT — Evolution Racewerks catalog number for the N20 Sports Series 4" high flow catted downpipe

VEHICLE APPLICATIONS