Evolution Racewerks BMW B58 F and G Chassis 4.5-inch High Flow Catted Downpipe
Unlock serious performance from your BMW B58 engine with the Evolution Racewerks 4.5-inch High Flow Catted Downpipe. This premium 200 cell metallic sports cat downpipe is a proven upgrade for BMW M140i, M240i, 340i, 440i, G20 M340i, G30 540i, Z4 M40i, X3 M40i, X4 M40i and X5 M40i models. If you are searching for BMW B58 downpipe, B58 high flow catted downpipe, 200 cell sports cat, M140i downpipe, M240i downpipe, 340i downpipe or Z4 M40i downpipe in the UK, this is the quality, flow and fitment you want.
Built from 100 percent 304 stainless steel with a CNC machined 4.5-inch V-band turbo flange, TIG welded construction and a proper stainless flex section, this ER B58 catted downpipe reduces backpressure, improves throttle response and helps the turbo spool faster. The result is a sharper, stronger power delivery and a more engaging drive. We run this product ourselves and our customers consistently report excellent fitment, impressive drivability gains and robust durability.
Why this B58 4.5-inch catted downpipe is the upgrade you need
- High flow 200 cell metallic catalytic converter to replace the restrictive factory ceramic 900 cell cat
- Smoother exhaust flow for increased horsepower and torque potential on the BMW B58 turbo engine
- Faster turbo spool and better throttle response for M140i, M240i, 340i, 440i, M340i, 540i, Z4 M40i and X3 X4 X5 M40i
- Mandrel bent 4.5-inch to 4-inch transitions designed for minimal turbulence and reduced backpressure
- Precision CNC machined 4.5-inch turbo outlet flange for a seamless transition from the B58 turbo
- Proper stainless flex section retained for longevity and reduced stress on the turbo, manifold and exhaust
- 100 percent 304 stainless steel, 100 percent TIG welded, track tested durability
- O2 sensor location retained in the factory position
- Compatible with the factory exhaust system and aftermarket exhausts
- Includes all required hardware for a complete installation
- Limited Lifetime Warranty and made in the USA by Evolution Racewerks
How the 200 cell metallic sports cat makes the difference
The OEM downpipe uses a dense 900 cell ceramic core that creates major exhaust restriction and turbulence. ER’s 200 cell metallic core has larger passages that allow exhaust gases to flow more freely. Lower cell count equals higher flow which supports more power, quicker turbo spool and stronger response. Metallic cores also tolerate higher temperatures and are more durable than ceramic.
Smart 4.5-inch design for the BMW B58
The B58 turbocharger outlet is 4.5 inches. ER engineered a matching 4.5-inch CNC flange and long, smooth transitions to the rest of the system to prevent the step and turbulence you get with smaller inlets. Less turbulence near the turbo means less backpressure and better performance.
Options and finishes
- Finish: Brushed or Polished
- Optional Black Ceramic Thermal Coating rated to 2000°F to reduce under bonnet temperatures and further resist corrosion
- Optional additional O2 sensor bung for wideband monitoring, supplied with pre-installed plug
- Optional 1/8-inch NPT EGT bung for exhaust gas temperature sensors, supplied with pre-installed plug
Compatibility
BMW 1 Series F20 F21 B58 M140i and M140ix
BMW 2 Series F22 F23 B58 M240i and M240ix
BMW 3 Series F30 F31 F34 340i and 340ix
BMW 3 Series G20 M340i and M340ix
BMW 4 Series F32 F33 F36 440i and 440ix
BMW 5 Series G30 540i
BMW X Series G01 X3 M40ix, G02 X4 M40ix, G05 X5 M40ix
BMW Z Series G29 Z4 M40i
What is included
- ER B58 4.5-inch High Flow Catted Downpipe assembly
- All required installation hardware
- Limited Lifetime Warranty
We recommend replacing the downpipe gasket during installation for best results.
Fitting and support
Professional fitting available at Nforcd in Warwickshire. Request a quote: Sales@nforcd.com.
Part numbers
- BM-EXH018SCAT - Brushed
- BM-EXH018PCAT - Polished
- BM-EXH018TBCAT - Ceramic Thermal Coated Black
Manufactured by
Evolution Racewerks
Why buy from Nforcd
Enthusiast run, expert advice and customer proven products. We have installed and used this Evolution Racewerks B58 high flow catted downpipe on multiple customer cars and feedback has been outstanding for fit, finish, durability and on-road performance.
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