The MAD Titanium Axle Back gives your G80/G82 two cars in one: a refined, near-stock cruiser with the valves shut, and a hard-charging, burbling monster with them open. It runs off your factory valve control, so the whole personality of the car changes from the steering-wheel buttons.

How it works

• Valves closed: airflow routes through the muffler for a clean, quiet tone that's just a shade louder than factory — perfect for early mornings and long highway pulls.
• Valves open: most of the flow bypasses the muffler for a loud, aggressive note with proper burbles, all without any droning resonance.
• Always clean: even wide open, a portion of the airflow still passes through the muffler, so you get aggression without rasp — especially up high in the rev range.

Build & finishes

Titanium construction sheds significant weight over the OEM axle back, sharpening response and handling. Choose your tip finish to match the build: Brushed, Black, Carbon, or Burnt Titanium.

Fitment

BMW M3 (G80) & M4 (G82) with the S58 engine.

From KORE SPEED — Canadian-owned and enthusiast-run. Email support@korespeed.com with any fitment questions.