🔊 MAD Valved Axle-Back Exhaust System – BMW G80 M3 / G82 G83 M4 (S58 Engine)

Unlock the true sound of your G8X M3 or M4 with the MAD Valved Axle-Back Exhaust System – engineered to deliver the aggressive, refined tone your S58-powered M car deserves. Designed for enthusiasts who expect both performance and sound quality, this exhaust transforms your driving experience with OEM+ fitment, deeper tone, and a smoother exhaust note.

🔥 Why Upgrade?

While the G80 M3 / G82 M4 are incredible performance machines, the stock exhaust system still suffers from the same issue as its predecessor – a flat, raspy tone that lacks depth and emotion. The MAD axle-back system addresses this directly, offering a clean, aggressive, and refined exhaust note that stays civil when needed and wild when desired.

Pair it with the optional MAD single midpipe for an even fuller, louder, and smoother sound without rasp or drone.

⚙️ Performance-Driven Design

• 📈 +5 HP / +5 lb-ft gains with improved exhaust flow

• 🔊 Louder, deeper exhaust tone with minimized raspiness

• 💨 76mm piping diameter (vs. OEM 70mm) reduces backpressure and enhances throttle response

• ⚙️ Valved design retains factory electronic actuators and M-Drive functionality

• 🧰 7 lbs lighter than stock axle-back system (Stock: 44 lbs / MAD: 37 lbs)

• 🔇 Drone reduction technology for comfort during highway cruising

🧩 Intelligent Valve Control

The MAD system uses the OEM exhaust valve motors for factory-like behavior:

• Valves Closed → Gases route through the MAD muffler and exit the inner tips, keeping the sound deeper and controlled during low-speed or comfort driving.

• Valves Open → Gases bypass the muffler via a near straight-pipe path, exiting through the outer tips for maximum sound and flow under throttle.

🔩 Seamless Integration

• 🔧 Connects directly to the OEM midpipe (cutting required) or to the MAD single midpipe (no cutting required)

• ✅ Factory-style fitment using included hardware

• 🔁 Fully reversible install

• 🧰 Includes extended valve harness for proper integration

🎨 Premium Materials & OEM+ Aesthetic

• 💎 Constructed entirely from TIG-welded 100% T304 stainless steel

• 🧼 Brush-finished throughout for a clean, high-end appearance

• 💥 Includes quad 4.5-inch (114mm) clamp-on tips for an aggressive look that fills the OEM cutouts perfectly

• 🎯 Designed to meet the expectations of refined performance car enthusiasts

📦 Fitment:

• 2021+ BMW G80 M3 (S58)

• 2021+ BMW G82 M4 Coupe (S58)

• 2021+ BMW G83 M4 Convertible (S58)

✅ Compatible with both RWD and xDrive
✅ Retains all factory electronic valve functionality

🏁 Experience the Sound BMW Forgot to Give You

Whether you're carving corners in M Mode or cruising in Comfort, the MAD Axle-Back Exhaust System adapts to your driving mood—delivering a rich, commanding tone that transforms your G8X into the M car it was meant to be.

🛒 Order today and hear the difference MAD makes.1,