Restrictions in the exhaust system robs horsepower and torque especially on turbocharged cars. Thus, removing as much exhaust flow restrictions will increase horsepower and torque significantly. The factory catalytic converter found in the factory downpipe is a big culprit of this and is a major exhaust flow restriction. The factory catalytic converter is made up of catalyst material formed into "honeycomb" weaves. Exhaust gas must pass through these tiny "honeycomb" weaves on their way to the exhaust system thus causing a major exhaust flow restriction. It also causes turbulence after the catalytic converter which causes the exhaust flow to slow down (which increases restriction). By replacing the factory downpipe/catalytic converter with Evolution Racewerks Sports Series 4" High Flow Catted Downpipe, more power is unleashed! The factory catalyter uses a 400 cell ceramic core. What the 400 cells means is that per every inch, there are 400 "cells" that the exhaust gas must pass through. Evolution Racewerks use a 200 cell metallic core. By having less cells per square inch, these individual "cells" are bigger in size thus allowing exhaust gas to pass through it more easier. Thus, the lower the cell count, the higher the flow. Higher flow = more power, faster turbo spool up (less turbocharger lag) and better throttle response. Bottom line, faster. The benefits of a metallic catalytic converter vs a ceramic like the factory is that it can take more heat and is more durable (last longer). They are also lighter than their ceramic counterparts.

Evolution Racewerks Sports Series Catted Downpipes is constructed out of 100% 304 grade stainless steel and utilize mandrel bent piping. They are 100% TIG welded by Evolution Racewerks in house fabricators and built in the USA. The factory turbocharger turbine housing utilizes a 4" V-Band flange which Evolution Racewerks have duplicated and CNC machined cut out of billet 304 stainless steel. Stainless Steel CNC machined O2 sensor and laser cut brackets are TIG welded using stainless steel rods. The O2 sensor is positioned at the factory location. Since the outlet of the turbocharger is 4" and the factory exhaust system is 2.5", the factory downpipes reduces size using short transitions from 4" before the catalytic convert and 2.5" afterwards. Due to space needed for the cataylic converter, the factory downpipes reduce in size using very short transitions. Since Evolution Racewerks catted downpipes utilize a s more compact cataylic converter, they have more space. Thus, they use very long transitions. These longer transitions allow the exhaust gas time to smoothly transition from the larger piping to the smaller. This results in less exhaust turbulence and backpressure which again improves throttle response and increase turbocharger spool times (less turbocharger lag).

Evolution Racewerks downpipes are designed to fit perfectly with either the factory exhaust system or your aftermarket exhaust system. There are no compatibility issues whatsover.

Features:

• Available for the 2012+ BMW 335i (F30 Chassis) N55 Engines!
• Available for the 2013+ BMW 435i (F32/F33 Chassis) N55 Engines!
• Available for the 2012+ BMW M135i (F20/F21 Chassis) N55 Engine!
• High Flow 200 cell metallic catalytic converter used
• Higher Max Horsepower Power Curve.
• Higher Intial Torque Curve. Torque curve hits faster and higher and longer.
• Better throttle response and faster turbo spool up times.
• Mandrel Bent 4" piping. Smooth transition to the exhaust system.
• 100% Stainless Steel Construction
• 100% TIG welded for better quality welds
• Precision CNC machined turbocharger V-Band flange.
• Brush Finish (standard) or optional Polish Finish
• Available with high temperature Black Thermal Coating to reduce underhood temperatures.
• Optional - Additional O2 sensor bung for wideband O2 sensors (comes with pre-installed plug)
• Optional EGT sensor bung for EGT gauges (comes with pre-installed plug)
• Compatible with the factory or aftermarket exhaust systems.
• Track tested durability.
• Includes all hardware for complete installation.
• Limited Lifetime Warranty.

Fitment:

• BMW M135i Single Turbo N55 Engine (F20/F21) 12-14

Notes:

• This product is intended for OFF ROAD USE ONLY.
• Not legal for use on pollution controlled vechiles upon public highways.
• This item is not for sale, installation, or use on licensed vehicles in the state of California.

.