Dinan Valved Axle-Back Exhaust System | BMW G80 M3 / G82 M4

The G8x M3/M4 deserves better than stock exhaust rasp. Dinan's valved axle-back system transforms the S58's thin vocals into a deeper, more aggressive soundtrack—without the cabin drone that plagued earlier generations. Engineered for versatility, the system uses computer-controlled valves to deliver refined civility at low speeds and full-throttle aggression when you demand it. Larger 76mm piping (vs. 70mm stock) reduces backpressure and unlocks +6 HP and +5 lb-ft of torque. When valves close, sound routes through the Dinan muffler for a subdued, controlled note. Open them up and gases bypass the muffler entirely for near-straight-pipe performance. Built entirely from T304 stainless steel and TIG welded, the system features quad 4.5-inch polished tips that fill factory cutouts perfectly—OEM+ aesthetics with serious attitude. Brush-finished construction and laser-engraved detailing ensure flawless appearance. At 38 pounds, it's 6 pounds lighter than stock while retaining factory valve actuators so you can adjust tone via M-drive settings. Pair it with Dinan's optional middle exhaust for an even louder, smoother, fuller experience. Factory fitment with included hardware makes installation seamless. This is the exhaust the G8x M3/M4 should have come with.