The F90 M5 is a twin-turbo V8 super sedan with all-wheel drive that can turn into rear-wheel drive with a few button presses. It deserves an exhaust that sounds as serious as it goes. From the factory, it mostly sounds polite.
The Dinan Free Flow Axle-Back Exhaust for the BMW F90 M5 and M5 Competition is built entirely from T304 stainless steel, TIG welded and brush finished. Dinan steps the tubing up to 83mm from 80mm stock, fits twin 76mm secondary valves that are 30% less restrictive than the factory valves, and finishes it in quad 4 in. double-walled, laser-engraved black ceramic tips. Dinan rates it at +6 HP and +5 lb-ft at 6,600 RPM.
How the Dinan M5 Axle-Back Exhaust Flows More
Bigger tubing and bigger valves mean the S63 pushes through less restriction when the valves are open. The factory valves and actuators stay in place, so valve behavior does not change. They stay closed to keep noise down at low speed and open under high load. Your exhaust mode button still does what it does today. No coding, no tune, no lost functionality.
Install and Legal Status
It is a bolt-on install using the factory mounting points, with about 2.4 hours of labor. The full system weighs 63 lbs. 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. It pairs with the Dinan F90 M5 Resonator Delete Kit if you want more volume. Dinan part number D660-0079-BLK. Sold by AutoTecknic, an authorized Dinan dealer.
What's Included
- Dinan T304 stainless steel valved axle-back exhaust
- Quad 4 in. double-walled black ceramic clamp-on exhaust tips
- Installation hardware
Key Features
- Dinan-rated +6 HP and +5 lb-ft at 6,600 RPM
- 83mm tubing, up from 80mm stock
- Twin 76mm secondary valves, 30% less restrictive than the factory valves
- Retains factory valves and actuators, no coding required
- T304 stainless steel, TIG welded, brushed finish
- Quad 4 in. (102mm) double-walled, laser-engraved black ceramic tips
- Bolt-on install, about 2.4 hours
- Emissions legal in all 50 states (does not affect emissions)
Vehicle Fitment
Fits the S63-powered BMW M5:
- BMW M5 / F90 Sedan (2018-2023): M5, M5 Competition
Installation Notes
A DIYer with a lift can handle it, and a shop familiar with F90 cars will have it done in about 2.4 hours. Let the exhaust cool completely and have a helper for lifting the 63 lb system into place. Follow the Dinan instructions included with the kit.
- Raise and support the car and let the exhaust cool fully.
- Unplug the factory valve actuators and loosen the clamps ahead of the rear mufflers.
- Unhook the hangers and remove the factory rear section.
- Hang the Dinan axle-back, fit and reconnect the factory valve actuators.
- Fit and align the clamp-on tips, tighten all hardware, then start the car and cycle the exhaust modes to confirm valve operation.
