Milltek Sport Axle-Back Rear Silencer Bypass Back Box/Muffler Delete, Non-Valved, GT-90 90mm Titanium Tips - BMW 1 Series 125i F20/F21 B48 2016+ - Fits 3 & 5 Door Hatch, M135i Diffuser/Rear Valance - UK 304 Stainless, Louder Exhaust

Milltek Sport valve-less rear section muffler delete with 90 mm titanium tips for BMW 1 Series 125i F20 F21 B48 2016 onward - suits M135i diffuser

Transform the character of your BMW 125i with this Milltek Sport axle-back upgrade. By replacing the factory back box with a free-flowing rear section and premium 90 mm titanium tailpipe finishers, your 1 Series gains a sharper, motorsport-inspired soundtrack and a purposeful look that complements the M135i style rear diffuser. It is the perfect choice for drivers who want a bolder tone on throttle while remaining civilised on the motorway without intrusive cabin boom.

Engineered and hand finished in the UK from high grade 304 stainless steel, this rear section features precision mandrel-bent pipework for consistent diameter and optimised gas flow. The result is durable construction, excellent corrosion resistance and that unmistakable Milltek performance sound. The titanium tip set delivers a lightweight, high-end finish that sits beautifully in the M135i valance.

Highlights

• Back box delete rear section for increased volume and a more aggressive exhaust note
• 90 mm titanium tailpipe finishers for a premium, motorsport look in the M135i style diffuser
• Valve-less design for consistent tone and reliable operation
• Crafted in the UK from type 304 stainless steel for long-term durability
• Mandrel-bent tubing for smooth flow and responsive performance
• Refined at cruise yet assertive under load with minimal cabin resonance
• Direct-fit to the OEM system using factory mounting points

Compatibility

• BMW 1 Series 125i F20 and F21 hatchback
• B48 engine only
• Model years 2016 onward
• Designed to suit the M135i rear valance diffuser
• Suitable for 3 door and 5 door models

Why enthusiasts choose this upgrade

We have fitted and driven this Milltek rear section on customer cars and our feedback has been consistently positive. Owners love the deeper tone, the enhanced presence on acceleration and the clean fit of the 90 mm titanium tips in the M135i diffuser. It is a quality, UK-built solution that looks right and sounds right on the B48-powered 125i.

Professional installation

For expert fitting, book with MJ Modifications in Warwickshire. Our team knows BMW performance exhausts inside out and will install with care and precision. Request a quote at info@mjmodifications.co.uk.

Search terms customers use

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