Cobra Sport BMW M135i F40 OPF/GPF/PPF-Back Exhaust, Back Box Muffler Delete, Rear Silencer & Centre Section Delete, Non Valved 76.2mm (3 inch) 1 Series M135i F40 Performance Upgrade

Transform the soundtrack of your BMW M135i F40 with this Cobra Sport OPF-back rear section upgrade. This non valved back box delete replaces the middle and tail sections after the gasoline particulate filter, delivering a louder, deeper and more aggressive tone without touching the factory catalyst or GPF/PPF. If you are searching for a BMW 1 Series M135i F40 muffler delete, OPF-back system, PPF-back exhaust, rear silencer delete or centre section delete, this is the precision-built solution enthusiasts choose.

Engineered in 76.2 mm tubular diameter, the system frees up flow from the particulate filter back while keeping emissions hardware in place. Expect a bolder idle, richer bass through the revs and serious presence on throttle. We have fitted this setup for customers and the feedback has been outstanding for sound quality, fit and finish.

• Designed for BMW M135i F40 platform, OPF-back configuration that replaces centre and rear sections
• 76.2 mm pipework for improved gas velocity and a more intense note
• Non valved fixed-tone layout for consistent sound in all drive modes
• Supplied with the required clamps, gaskets and fittings for a straightforward installation
• Keeps the original catalyst and particulate filter in place
• Tailpipe choices in 4 inch, including carbon fibre tip options for a premium finish

Measured sound increase

• Idle: 73.5 dB, up by 10.5 dB
• Static 3,800 rpm: 95.1 dB, up by 13.1 dB

Why choose this M135i F40 OPF-back exhaust

• Back box delete and centre section replacement for a race-inspired soundtrack
• Direct-fit, bolt-on upgrade that maintains all factory emissions components
• Ideal for drivers searching for a BMW 1 Series F40 exhaust upgrade, M135i rear silencer delete or OPF-back performance system
• Cobra Sport quality with a fully guaranteed product and excellent long-term reliability

Non valved explained

This version does not use exhaust valves, so switching drive modes will not alter the volume. There is no adverse effect on how the car runs. You simply enjoy the consistent, tuned tone that Cobra Sport designed into this system.

Fitting and support

Professional installation recommended. For expert fitting, book with MJ Modifications in Warwickshire. Request a quote by emailing info@mjmodifications.co.uk.