Description
The Evolution Racewerks Sports Series 4" High Flow Catted Downpipe for the 2020–2024 BMW M135iX B48 engine is engineered to dramatically increase horsepower, torque, and turbo efficiency. Featuring a high-flow 200 cell metallic catalytic converter, CNC-machined V-band flange, mandrel-bent 4" stainless steel piping, and a factory-style flex section, this downpipe delivers exceptional performance with OEM-level fitment and durability.
Developed and manufactured in-house in the USA, this downpipe provides faster turbo spool, stronger torque curve, improved throttle response, and smoother exhaust flow thanks to long transitional piping and reduced restriction.
Key Features
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Made in the USA and manufactured in-house
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Designed specifically for the 2020–2024 BMW M135iX B48 engine
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High Flow 200 cell metallic catalytic converter
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Average gains of 9–11 whp (results vary by setup)
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Average torque gains of 15 wtq on stock boost, up to 20+ wtq with tuning
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Higher peak horsepower and stronger torque curve
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Faster turbo spool and improved throttle response
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Mandrel-bent 4" piping with smooth, long exhaust transitions
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100% 304 stainless steel construction
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100% TIG-welded for maximum strength
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CNC-machined turbocharger V-band flange
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CNC-machined ball joint flange with smooth interior for optimized flow
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Stainless steel flex section for exhaust movement and component protection
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Available in mirror polish or brushed finish
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Optional high-temp black ceramic thermal coating
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Optional additional O2 sensor bung (plug included)
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Optional EGT bung (plug included)
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Compatible with factory and aftermarket exhaust systems
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Track-tested durability
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Includes hardware for full installation
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Limited Lifetime Warranty
Performance Advantages
The factory downpipe utilizes a restrictive 900 cell ceramic catalytic converter, creating significant exhaust flow resistance and turbulence. The Sports Series 200 cell metallic core drastically increases flow capacity, enabling the turbocharger to spool faster and operate more efficiently. This results in better throttle response, stronger low-end torque, and increased peak horsepower.
Metallic catalysts tolerate higher temperatures and last longer than ceramic units while also being lighter. The long gradual transitions in this downpipe reduce turbulence and backpressure more effectively than the short transitions found in the factory unit.
The included stainless steel flex section prevents stress on the turbocharger, exhaust manifold, and downpipe. This is crucial for long-term durability, especially on lowered vehicles where the exhaust system is more likely to contact the ground.
xDrive AWD Version
On xDrive models, the driveshaft sits directly below the downpipe, limiting removal space. Factory-style downpipe removal normally requires disconnecting the driveshaft or lowering the front subframe, increasing labor time.
The Evolution Racewerks 2-piece xDrive version eliminates this issue, allowing full removal and installation without driveshaft disconnection or subframe lowering—saving significant time and cost.
OPTIONS
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Ceramic Thermal Coating (Black Only)
Reduces underhood temperatures, increases exhaust gas velocity, lowers backpressure, and adds corrosion resistance. Rated up to 2000°F. -
Additional O2 Sensor Bung
For wideband O2 sensors and air/fuel ratio gauges. Pre-installed plug included. -
Optional EGT Bung (1/8" NPT)
For EGT temperature probes and gauges. Pre-installed plug included.
Legal Notice
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For off-road competition use only
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Not legal for use on public highways or emissions-controlled vehicles
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Not for sale, installation, or use on licensed vehicles in California
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Requires Vehicle Compliance Waiver (USA)
