Active Autowerke Maad Maxx Triple-Can Valved Axle-Back/Axleback Exhaust Rear Silencer/Muffler Back Box for BMW M3/M4 F80 F82 F83 (F8X S55) | Tri-Chamber Drone-Reducing Rear Section

Active Autowerke Maad Maxx Triple Canister Valved Rear Silencer for BMW F80 F82 F83 M3 and M4

Turn the F8x S55 soundtrack into something genuinely special. The Maad Maxx tri‑chamber valve‑controlled rear section from Active Autowerke replaces the stock back box on the F80 M3, F82 M4 and F83 M4 Convertible with a richer, deeper note, cleaner tone and reduced cabin boom. If you are after a premium rear silencer upgrade for your M3 or M4 that delivers road‑friendly refinement with motorsport character when you want it, this rear section is the one to have.

We run this system ourselves and have installed it for numerous customers. Feedback has been outstanding: fuller bass, less rasp, great cold‑start presence and a quality fit that looks factory. Pair it with the Active Autowerke F8x mid‑pipe for the ultimate S55 sound and impressive performance gains.

Why enthusiasts choose this rear section

• Beautifully balanced tone that removes the thin, buzzy rasp common on standard systems
• Valve‑equipped rear section gives you quiet cruising and aggressive volume on demand
• Triple canister architecture for superior resonance control and reduced drone on the motorway
• Axle‑back design optimised for the F8x platform to improve flow and response
• Precision fit on the F80, F82 and F83 with all hardware included for a straightforward bolt‑on install

Key features

• Made in the USA
• 18+ whp and 30+ lb‑ft when combined with the Active Autowerke F8x mid‑pipe
• Quicker turbo spool characteristics
• Low, bass‑rich rumble with an assertive M tone under load
• Flex joints to minimise vibration
• Triple‑canister muffler design to tame resonance and cut drone
• Each system is test‑fitted on an F8x jig for spot‑on alignment
• Direct fit for BMW F80 M3, F82 M4 and F83 M4 Convertible
• Supplied with all necessary installation hardware

Tailpipe finishes

• Matte black
• Carbon fibre
• Brushed stainless steel

Real‑world results

Mustang dyno figures with full Active Autowerke exhaust system:

• Stock: 380 whp and 371 wtq
• Full Active Autowerke system: 398 whp and 401 wtq
• Full Active Autowerke system run 2: 397 whp and 398 wtq

Note: Power gains are achieved when this Maad Maxx valved rear section is paired with the Active Autowerke F8x mid‑pipe.

Vehicle compatibility

• BMW F80 M3 2012–2015
• BMW F80 M3 LCI 2015–2018
• BMW F82 M4 2013–2017
• BMW F82 M4 LCI 2016–2019
• BMW F83 M4 Convertible 2013–2017
• BMW F83 M4 LCI Convertible 2016–2019

Installation and fitting

Direct bolt‑on axle‑back with hardware included. Professional fitting recommended for best results.

Want it supplied and fitted. MJ Modifications in Warwickshire offer expert installation for BMW M3 and M4 exhaust upgrades. Request a quote at info@mjmodifications.co.uk.

Part number

11-073

Buy with confidence

We have hands‑on experience with this system on our own cars and customer builds. The Maad Maxx triple‑can valved rear section delivers a premium soundtrack, excellent drivability and OE‑level fit. Order today for your S55‑powered F8x and enjoy a proper M car tone without the unwanted drone.

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