E90 · E92 · E93 M3
E9x M3 brake cooling ducts
About an hour a side·Jack and stands, the wheel socket, a trim tool
Sold each. Left and right are different shapes. One is the closed wedge. The other has the round port. A non-M E90 or E92 does not use this duct.
Step 01
Wheel off, liner back
Car on stands. Wheel off. Pull the liner back far enough to see the bumper opening and the path to the rotor. Do not work under a car on a jack.
Done when. You can see the opening and the rotor.
Step 02
The right shape for that side
Match the print to the side. The closed wedge and the ported duct are not interchangeable, and neither one flips. The mouth goes at the bumper opening. The small end points at the rotor.
Done when. The mouth sits in the opening without being forced.
Step 03
Hose and clamp
If you bought the duct only, the hose and the metal clamp are yours. Slide the hose on the small end and clamp it. The other end of the hose aims at the rotor, not at the tire.
Done when. The clamp is tight and the hose misses the tire.
Step 04
Liner and wheel
Liner back. Wheel on, and torque the bolts on the ground. Turn the wheel lock to lock. The duct and the hose never touch the tire. Then the other side, with the other print.
Done when. Lock to lock, nothing touches the tire.