The RK Autowerks 4.5” catless downpipe is designed to reduce exhaust restriction and backpressure for faster turbo response and measurable horsepower and torque gains. Developed using advanced 3D scanning and prototyping, it delivers OEM-level fitment and proper alignment.
Built from mandrel-bent T304 stainless steel with a CNC-machined velocity stack turbo flange, this downpipe improves flow right at the turbine outlet. Precision TIG-welded construction and stainless V-band/exhaust flanges provide a strong, leak-resistant seal for long-term reliability. O2 sensor bungs are positioned in the factory locations for straightforward installation.
Features
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T304 stainless steel construction with mandrel bends
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Precision TIG-welded joints
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Heavy-duty stainless V-band / exhaust flanges
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Factory O2 sensor locations retained (stainless bungs)
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Helps reduce under-hood temperatures (via reduced restriction)
Fitment
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2019+ Toyota Supra 3.0L
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2016–2019 BMW 340i / xDrive
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2020+ BMW M340i / xDrive
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2015+ BMW M240i / xDrive
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2016+ BMW 440i / xDrive
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2016+ BMW 540i / xDrive
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2016+ BMW 740i / xDrive
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2017–2020 BMW X3 M40i
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2017–2020 BMW X4 M40i
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2019+ BMW G05 X5 40i / xDrive
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2019+ BMW G07 X7 40i / xDrive
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2019+ BMW G29 Z4 M40i
WARNING (Emissions / Legal)
Catless downpipes are for off-road use only. Installation will typically trigger a Check Engine Light. Removal or modification of emissions equipment is prohibited for vehicles operated on public roads in many jurisdictions.
