The E90 M3 is the sleeper of the E9x family. Four doors, a quiet exterior and a high-revving S65 V8 underneath. The only thing that gives it away from behind is four small factory tips, and the stock mufflers keep that V8 more reserved than it deserves.
The Dinan Free Flow Axle-Back Exhaust with black tips for the BMW E90 M3 Sedan uses a straight-through canister design to cut restriction behind the rear axle. On Dinan's dyno it adds 6 HP and 5 lb-ft at 6800 RPM, and it weighs 10 lb less than the stock axle-back.
How the Dinan Axle-Back Exhaust Sounds on the E90
A sedan still needs to be livable. Dinan built a Helmholtz chamber into the system, a tuned resonance cavity that cancels drone, so highway cruising stays calm for everyone in the car. Put your foot down and the S65 gets louder and sportier all the way to redline.
It is 100% 304 stainless steel, finished with quad 3 in. tips that are black ceramic coated and laser engraved. The black tips suit the understated look of the sedan while still signaling that something is different.
Axle-Back Exhaust Fitment and Legal Status
It is a bolt-on part that uses the factory brackets and hangers, with clamps included, and Dinan lists 1.6 hours of labor. It sits behind the catalytic converters and does not affect emissions, and Dinan classifies it as legal for sale and use on emissions-controlled vehicles. Dinan part number D660-0028. Sold by AutoTecknic, an authorized Dinan dealer.
What's Included
- Dinan Free Flow Axle-Back Exhaust in 304 stainless steel
- Quad 3 in. black ceramic coated, laser engraved tips
- Clamps
Key Features
- Dinan-tested +6 HP and +5 lb-ft at 6800 RPM
- 10 lb lighter than the stock axle-back
- Straight-through canister design for reduced restriction
- Helmholtz chamber to reduce highway drone
- Quad 3 in. black ceramic coated, laser engraved tips
- 100% 304 stainless steel construction
- Uses factory brackets and hangers for a factory-like fit
- Legal on emissions-controlled vehicles per Dinan
Vehicle Fitment
Fits the following S65 V8-powered BMW M3 model:
- BMW M3 / E90 Sedan (2008-2011): M3
For the E92 Coupe and E93 Convertible M3, see Dinan part D660-0027.
Installation Notes
Dinan lists 1.6 hours of labor. A lift makes it easier, but jack stands, basic hand tools and a helper will do. Let the exhaust cool completely first.
- Safely raise and support the rear of the car.
- Loosen the clamps at the factory axle-back joints and unhook the factory mufflers from their hangers.
- Hang the Dinan axle-back on the factory brackets and connect it with the supplied clamps.
- Center the quad tips in the bumper cutouts and tighten all clamps.
- Start the engine and check every joint for leaks and clearance to the body.
