Milltek Cat-back Exhaust for BMW 5 Series M5 & M5 Competition 4.4l Twin Turbo F90 LCI (OPF/GPF Equipped Cars) (2021 onwards) – Sharper Sound, Reduced Back Pressure
This is Milltek's cat-back system for the BMW 5 Series M5 & M5 Competition 4.4l Twin Turbo F90 LCI (OPF/GPF Equipped Cars). It replaces everything from the factory catalytic converter rearward with wider-bore pipework, a re-profiled mid-pipe and silencers tuned specifically for this platform, cutting back pressure and sharpening the exhaust note. The factory catalytic converter stays in place, so the car's emissions hardware is left as standard. It's offered in 5 tailpipe finishes, so you can pick the setup that suits how the car's used.
It's aimed at owners who want a noticeably different sound and a genuine, if modest, flow improvement without touching anything upstream of the cat: check the notes on each version below, as some need supporting software.
Specifications
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System Type: Cat-back
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Pipe Diameter: 80mm (3.15")
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EC Approved: No
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Race System: Yes
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Fitting Time: approx. 3 to 4 hours (Milltek figure)
Key Features
- Made from T304L aircraft-grade stainless steel, which is anti-magnetic and resists discolouration
- Mandrel-bent pipework keeps a constant diameter through every bend for unrestricted flow
- 80mm (3.15") pipework
- Replaces the standard exhaust from the catalytic converter back, so the factory cat is retained
- Choice of 5 tailpipe finishes: GT-100 Brushed Titanium, GT-100 Burnt Titanium, JET-100 Carbon Fibre, GT-100 Cerakote Black, GT-100 Polished
- Designed, developed and manufactured in the UK by Milltek Sport
Fitment
- BMW 5 Series M5 & M5 Competition 4.4l Twin Turbo F90 LCI (OPF/GPF Equipped Cars) (2021 onwards)
Not suitable for: the BMW 5 Series M5 & M5 Competition 4.4l Twin Turbo F90 (OPF/GPF Equipped Cars), which needs the Milltek Cat-back Exhaust BMW 5 Series M5 & M5 Comp 4.4l Twin Turbo F90 OPF/GPF 20-21; the BMW 5 Series M5 Saloon M TwinPower Turbo V8 (F10), which needs the Milltek Cat-back Exhaust BMW 5 Series M5 Saloon M TwinPower Turbo V8 F10 11-16.
Installation
Milltek quotes a fitting time of approx. 3 to 4 hours. Some versions: Cat Back System inc. OPF/GPF Bypass with Brushed Titanium GT-100 Trims - Required Stage 2 ECU Software or OPF/GPF Bypass Module - For Vehicles with Flange Connection to OE Downpipes. Some versions: Cat Back System inc. OPF/GPF Bypass with Burnt/Blue Titanium GT-100 Trims - Required Stage 2 ECU Software or OPF/GPF Bypass Module - For Vehicles with Flange Connection to OE Downpipes. Some versions: Cat Back System inc. OPF/GPF Bypass with Carbon JET-100 Trims - Required Stage 2 ECU Software or OPF/GPF Bypass Module - For Vehicles with Flange Connection to OE Downpipes. Some versions: Cat Back System inc. OPF/GPF Bypass with Cerakote Black GT-100 Trims - Required Stage 2 ECU Software or OPF/GPF Bypass Module - For Vehicles with Flange Connection to OE Downpipes. We recommend professional fitting on a ramp. Once fitted, check the tailpipe alignment and re-check all clamps after the first few hundred miles.
Upgrade Further
Also available from Milltek for this car: Milltek GPF/OPF Bypass BMW 5 Series M5 & M5 Comp 4.4l Twin Turbo F90 LCI OPF/GPF 21+.
Which tailpipe finishes are available?
You can choose from: GT-100 Brushed Titanium, GT-100 Burnt Titanium, JET-100 Carbon Fibre, GT-100 Cerakote Black, GT-100 Polished. The finish is cosmetic and does not change the sound.
Does it fit the BMW 5 Series M5 & M5 Competition 4.4l Twin Turbo F90 (OPF/GPF Equipped Cars)?
No. For that car, choose the Milltek Cat-back Exhaust BMW 5 Series M5 & M5 Comp 4.4l Twin Turbo F90 OPF/GPF 20-21.
Is it road legal?
Milltek lists this as a race part without EC approval, so it is intended for off-road and competition use.
Do I need a remap?
Some versions do. Milltek notes: "Cat Back System inc. OPF/GPF Bypass with Brushed Titanium GT-100 Trims - Required Stage 2 ECU Software or OPF/GPF Bypass Module - For Vehicles with Flange Connection to OE Downpipes". Check the notes for the version you choose.
Does it keep the factory catalytic converter?
Yes. It fits behind the factory catalytic converter, which stays in place.
How long does it take to fit?
Milltek quotes approx. 3 to 4 hours.
What is it made from?
T304L aircraft-grade stainless steel, which is anti-magnetic and resists discolouration better than lower grades.
Is there a warranty?
Yes. Milltek products are covered against defects in materials and workmanship. Contact us with your order number if you have a problem.
