1 1

Remus

Remus BMW M135i/M235i N55 Valved Rear Silencer Backbox Muffler – Axle-Back Sports Exhaust (F20 F21 F22 F23, incl xDrive) | Switchable Flap, OE Valve Control, EC Approved Stainless Steel | 1 Series/2 Series

Remus BMW M135i/M235i N55 Valved Rear Silencer Backbox Muffler – Axle-Back Sports Exhaust (F20 F21 F22 F23, incl xDrive) | Switchable Flap, OE Valve Control, EC Approved Stainless Steel | 1 Series/2 Series

£423.31
£470.35 £423.31
Sale Sold out
Shipping calculated at checkout.

Heads-up on cancellations & returns: if you cancel an order or return an item, you won't get back 100% of what you paid. We apply a 10% restocking fee, the outbound shipping is non-refundable, and we have to pass on Shopify / PayPal payment processing fees; these aren't returned to us when we refund you. International orders also lose on exchange-rate spread in both directions. If the original packaging is damaged or missing, a reboxing charge applies. For international orders specifically, if you refuse to pay our shipping invoice or supply a prepaid label after placing the order, the same deductions apply. We're upfront about this — please be sure of your purchase before ordering.

Switchable Rear Box for BMW M135i and M235i, EC Approved Stainless, OE Flap Control

Give your M Performance hatch or coupe the voice it deserves with this Austrian-made switchable rear box. Designed for the 3.0 turbo straight-six platform, it delivers a deeper, motorsport-inspired soundtrack under throttle while remaining calm and civil on the motorway with the flap closed. The built-in valve works seamlessly with the factory actuator and vehicle electronics for genuine OE-style operation and everyday usability.

Crafted from shot-blasted, corrosion resistant stainless steel and precision welded for strength, this performance rear section reduces back pressure and improves gas flow. The result is a sharper response and a richer tone without unwanted cabin drone. It is EC approved for road use and built to last.

We have installed this system many times at MJ Modifications in Warwickshire and feedback has been outstanding. Customers praise the clean fit, premium finish and the perfect balance between sporty character and long-distance comfort.

Why this upgrade stands out

  • Switchable sound, aggressive when you want it, refined when you need it
  • Factory flap integration via the original actuator and on-board electronics
  • Shot-blasted stainless construction and high quality welds for durability
  • Reduced back pressure and improved flow characteristics
  • Lightweight rear section with precise, OE-like fitment
  • Handmade in Austria to exacting standards
  • EC approved for road use

Tube diameter

  • Stock pipe: 80 mm
  • Performance pipe: 84 mm

What is included

Stainless steel sports rear silencer with valve integration for BMW M135i and M235i models using the OE control system. Tailpipe trims are required and are supplied separately.

Build your system

Axle-back setup - add:

  • Remus BMW N55 F20 F21 M135i Black Tailpipes, pair

Cat-back setup - add:

  • Remus BMW N55 F20 F22 Catback Front Section, for M135i and M235i
  • Remus BMW N55 F20 F21 M135i Black Tailpipes, pair

Turbo-back setup - add:

  • Remus BMW N55 F20 F22 F30 F32 Racing Downpipe 200 CPSI, for M135i, M235i, 335i and 435i
  • Remus BMW N55 F20 F22 Catback Front Section, for M135i and M235i
  • Remus BMW N55 F20 F21 M135i Black Tailpipes, pair

Prefer a louder track-biased note Only for off-road or circuit use, a non EC approved racing rear box is available separately.

Fitment

  • 1 Series F20 F21 M135i including xDrive, July 2013 onward
  • 2 Series F22 F23 M235i, 2014 onward

Professional installation

We recommend expert fitting. MJ Modifications offers installation at our Warwickshire workshop, request a quote via info@mjmodifications.co.uk.

Compatibility check before dispatch

To ensure perfect fit, add your UK registration or the last 7 of your VIN at checkout and we will verify compatibility prior to shipping.

Part number

088014 0500

Manufacturer and warranty

Manufacturer: Remus

Warranty: 2 year Remus warranty, non transferable

Search terms, M135i backbox, M135i rear box, M135i muffler, M135i sports exhaust, F20 performance rear silencer, F21 rear muffler, M235i back box, M235i rear section, F22 performance exhaust, F23 performance muffler, BMW 1 Series sports exhaust upgrade, BMW 2 Series exhaust upgrade, switchable flap exhaust, valve controlled rear box, OE actuator exhaust, EC approved rear silencer, stainless steel rear box, Austrian made muffler, road legal performance exhaust, BMW M Performance exhaust alternative, axle back system, rear section upgrade, performance rear silencer BMW, BMW straight six turbo exhaust.

View full details