Milltek Rear Silencer Bypass (Back Box Delete) Non-Valved with GT-80 Polished Tips | OE Twin Left Valance | BMW 125i F20/F21 3 & 5 Door B48 | 2016-on

BMW 125i F20 F21 B48 rear muffler delete with GT-80 polished tailpipes by Milltek Sport

Looking to unleash a sharper soundtrack from your 1 Series without altering emissions hardware? This UK-built Milltek Sport rear section replaces the factory rear box with a free-flow straight-through design for a stronger, crisper tone and a premium twin exit look. Perfect for 2016-on BMW 125i B48 turbo petrol models on the F20 and F21 platform with the left-side twin cut-out valance.

What makes this rear section a must-have

• Crafted from T304 grade stainless steel for durability in all weather conditions.
• Non-valved rear section for consistent, more vocal sound compared to the stock silencer.
• Precision-bent tubing for smooth gas flow and a more engaging drive.
• GT-80 mirror-polished tailpipe finishers for an OEM-plus twin left appearance.
• Engineered in the UK by Milltek Sport with a tone developed to minimise cabin boom.

Compatibility

• BMW 1 Series 125i F20 5-door, B48 engine, 2016 onwards.
• BMW 1 Series 125i F21 3-door, B48 engine, 2016 onwards.
• Suits cars with the factory twin-left rear valance aperture.

Included in the box

• Rear box replacement section without valve control.
• Pair of GT-80 80 mm polished tailpipes in twin left configuration.

The sound and feel

Expect a deeper idle, a cleaner, more aggressive note through the revs and a far more characterful driving experience. In our experience and from customer feedback, it hits the sweet spot for daily use while delivering the sporty tone enthusiasts want from the B48.

Fitting and support

Professional installation recommended. Book your fitment with MJ Modifications in Warwickshire. For a quote, email info@mjmodifications.co.uk.

Why buy from us

We have fitted this upgrade for many happy 125i owners and run it on customer cars. The finish, the sound and the UK-made build quality are consistently praised.

Search terms customers use

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