The S55 in your F80 M3 or F82 M4 is a proper M engine. Twin turbos, a hard-charging top end, and a factory exhaust that spends most of its life keeping the volume down. Put it in Sport+ and it wakes up, but it never quite sounds as sharp as it drives.
The Dinan Free Flow Axle-Back Exhaust for the BMW F80 M3, F82 M4 and F83 M4 Convertible keeps everything you like about the factory valved system and removes what holds it back. It is 100% 304 stainless steel, runs twin 76mm secondary exhaust valves, and finishes in quad 3.5 in. laser-engraved black ceramic tips. Dinan rates it at +5 HP, and at 56 lbs it is 3 lbs lighter than stock.
Dinan M3 and M4 Axle-Back Exhaust With Factory Valve Control
The big worry with any valved exhaust swap is losing the stock behavior. You will not. The Dinan system reuses the factory actuators, and valve operation is unchanged, so your M-Drive exhaust setting still controls the sound exactly as it does now. The valves stay closed to keep noise down at low speed and open fully under high load, where the larger 76mm valves let the S55 flow freely. Quiet start in the morning, full voice when you want it. No coding, no tune.
Install and Legal Status
It bolts to the factory brackets and hangers with about 1.8 hours of labor. Because it sits behind the catalytic converters and does not affect emissions, Dinan lists it as legal for sale and use on emissions-controlled vehicles in all 50 states. Dinan part number D660-0050-BLK. Sold by AutoTecknic, an authorized Dinan dealer.
What's Included
- Dinan 304 stainless steel valved axle-back exhaust
- Quad 3.5 in. laser-engraved black ceramic exhaust tips
- Installation hardware
Key Features
- Dinan-rated +5 HP
- Twin 76mm secondary exhaust valves
- Retains factory valve actuators and M-Drive exhaust control
- 100% 304 stainless steel construction
- Quad 3.5 in. laser-engraved black ceramic tips
- 56 lbs, 3 lbs lighter than stock
- Bolt-on install, about 1.8 hours, no coding or tune required
- Emissions legal in all 50 states (does not affect emissions)
Vehicle Fitment
Fits the following S55-powered BMW M models:
- BMW M3 / F80 Sedan (2015-2018): M3, M3 with Competition Package
- BMW M4 / F82 Coupe (2015-2020): M4, M4 with Competition Package
- BMW M4 / F83 Convertible (2015-2020): M4 Convertible, M4 Convertible with Competition Package
Installation Notes
A confident DIYer with a lift or solid jack stands can handle this, and a shop familiar with F8X cars will have it done in about 1.8 hours. Let the exhaust cool completely and follow the Dinan instructions included with the system.
- Raise and support the car and let the exhaust cool fully.
- Unplug the factory exhaust valve actuators and loosen the clamps ahead of the rear muffler.
- Unhook the rear hangers and remove the factory rear muffler assembly.
- Hang the Dinan axle-back, transfer the factory valve actuators, and connect them.
- Align the tips, tighten all clamps and hardware, then start the car and cycle the exhaust modes to confirm the valves operate.
