Milltek Sport OPF/GPF Back Valved Exhaust with Rear Silencer Bypass & GT-115 Polished Tips for BMW M8 & M8 Competition 8 Series (F91 Coupe, F92 Cabrio) 4.4L V8 Twin Turbo, 2020+, Stainless Steel, OPF/GPF Cars Only

Unlock a richer V8 soundtrack and sharpened response for your BMW 8 Series flagship with this GPF-back, valve-controlled rear section and GT-115 mirror polished tailpipe finishers. Tailored specifically for the 4.4 twin‑turbo V8, this premium T304 stainless system brings a deeper, more characterful tone, a bolder rear-end look and precision fitment that feels factory-plus. It keeps the factory particulate filters in place, delivering everyday refinement with an addictive, motorsport-inspired bark when the valves open.

Compatible vehicles

• BMW 8 Series M8 and M8 Competition 4.4 twin‑turbo V8
• F91 Coupé and F92 Cabriolet
• Model years from 2020 onwards
• For OPF and GPF equipped cars only – retains the original particulate filters and catalytic converters

Why enthusiasts choose this rear section

• Switchable valve control – calm and refined with valves closed, aggressive tone on demand with valves open
• Rear silencer bypass design for a more vivid, hard‑edged note without turning every cruise into a drone fest
• GT‑115 polished tailpipes – large diameter, mirror finish tips that fill the apertures and elevate the rear aesthetic
• Crafted in the UK from high-grade T304 stainless steel for durability, corrosion resistance and a consistently premium finish
• Mandrel‑formed tubing with enlarged diameter for smoother gas flow and sharper throttle response
• Developed to minimise cabin resonance for comfortable long‑distance driving
• Direct bolt‑on fitment for OPF/GPF models – commonly referred to as a GPF‑back or axle‑back upgrade on particulate filter cars

Built to perform and last

Hand‑finished in Britain by specialists using non‑magnetic T304 stainless throughout, this system features smooth-radius bends and carefully optimised pipework. The result is robust construction, consistent weld quality and a precise fit that aligns perfectly with the factory hangers and bumper cutouts. It looks as good as it sounds.

Sound you can tailor

With the valves closed you get a deeper bass line and a more cultured tone for daily driving. Open the valves and the V8 gains bite and clarity, with a crisp upshift crack and authentic performance character. Customers love the balance – more presence outside, controlled volume inside.

Proven with M8 owners

We have supplied and fitted this upgrade to both M8 and M8 Competition clients seeking a meaningful sound change, premium materials and OE‑level fitment. Feedback has been consistently positive on finish, valve operation and the refined, drone‑resistant acoustic tuning on both Coupé and Cabriolet models.

Ideal search terms and use cases

• BMW M8 rear section exhaust upgrade
• GPF‑back valved system for F91 F92
• Switchable flap exhaust with polished tailpipes
• Back box replacement for 8 Series M cars
• Axle‑back exhaust for particulate filter models
• T304 stainless performance rear silencer bypass
• Mirror polished GT‑115 tip set for M8
• Deep V8 sound upgrade with minimal drone

Fitting and support

Professional installation recommended. MJ Modifications offers supply and fitting in Warwickshire. For a fitting quote or to book your BMW 8 Series exhaust installation, email info@mjmodifications.co.uk.

Notes

• For OPF/GPF equipped F91 and F92 models from 2020 onwards
• Retains factory particulate filters and catalytic converters
• If you are unsure about compatibility, contact us and we will be happy to help