Remus Valved Switchable Axle-Back Rear Silencer Back Box/Muffler for BMW G20 G21 340i/M340i xDrive & G22 440i/M440i xDrive (B58) – Stainless Steel, OPF/GPF/PPF Compatible – 76mm Sport Exhaust – Part 085020 1500

Remus Switchable Rear Silencer Back Box for BMW G20 G21 340i xDrive and G22 440i xDrive

Unlock a richer soundtrack and real on-road performance with the Remus rear section for the B58-powered BMW G20 and G21 340i xDrive and the G22 440i xDrive. This premium stainless steel sports rear muffler replaces the factory back box to deliver a deeper, more characterful tone, enhanced response and a high quality finish that looks and sounds the part on both daily drives and spirited runs.

Engineered in Austria and shot blasted for durability, the Remus valve-controlled rear silencer uses a larger 76 mm tube diameter to reduce back pressure versus the 70 mm OEM setup. Dyno development recorded gains of up to +7.6 hp and +26.2 Nm, along with a 2.8 kg weight saving compared with the stock rear silencer. The valve integrates with the car’s factory electronics using the supplied original BMW actuator and Y-cable, so you keep quiet refinement in Comfort and an aggressive soundtrack in Sport.

We have fitted this system for many MJ Modifications customers and on our own builds, and the verdict is consistent - superb fitment, a mature exhaust note with no annoying drone at motorway speeds, and a meaningful uplift in character without compromise. It is a go-to upgrade for owners wanting a quality axle back solution that is OPF and GPF friendly on petrol particulate filter models.

Key reasons to choose this Remus rear section

• Switchable valve rear box for G20 G21 340i xDrive and G22 440i xDrive
• Noticeably deeper tone and stronger mid-range character without unwanted drone
• Reduced back pressure thanks to 76 mm pipework for improved throttle response
• Includes original BMW actuator and Y-cable for seamless OEM-style valve control
• Shot blasted stainless steel construction with precise fit and finish
• Up to +7.6 hp and +26.2 Nm in testing - with a 2.8 kg weight saving over stock
• Hand built in Austria with a 24 month Remus warranty
• Compatible with OPF and GPF equipped vehicles

Technical highlights

• Pipe diameter: 70 mm factory - 76 mm Remus
• Valve operation: controlled by OEM electronics via supplied actuator and Y-cable
• OPF and GPF compatibility: designed for vehicles with petrol particulate filters
• Measured development results: up to +7.6 hp and +26.2 Nm - weight saving 2.8 kg

Fitment

• BMW 3 Series G20 Saloon and G21 Touring 340i xDrive - 2020 onwards
• BMW 4 Series G22 Coupe 440i xDrive - 2021 onwards

Part number: 085020 1500

Tailpipe choices and system expansion

Complete the look with your preferred Remus tailpipe design to suit your build. For a track-only cat-back setup, pair this rear section with the non-resonated GPF replacement section and the appropriate connection tube, then choose your desired tips.

Installation, support and compatibility check

Prefer professional fitting and alignment of your new rear silencer back box upgrade We can help. Book installation with MJ Modifications in Warwickshire - request a quote at info@mjmodifications.co.uk. For peace of mind, we can run a compatibility check before dispatch. Add your UK registration or the last 7 digits of your VIN at checkout.

Road legality and tuning notes

Racing components and parts without EC approval are generally not permitted for road use. When using sports silencers, full systems or GPF replacement parts intended for closed-course use, an ECU calibration can be beneficial to maximise performance and to help prevent potential warning lights.

Manufacturer and warranty

Brand: Remus

Warranty: 24 months - non transferable

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