BMW E30 Intake Adapter (M20 and M42 engines) - Gen 2
Attaching a cone air filter to the square air flow meter (AFM) inlet requires an adapter to manage the transition from the circular cross-section of the cone filter to the square cross-section inlet of the AFM. We've seen many cheap, poorly designed adapters on the market with an abrupt transition from circular to square cross-section that likely flow worse than the stock configuration. You can read more about the technical aspects of it here.
It takes several extra manufacturing processes and is labor-intensive to make an intake adapter with a smooth transition, but we did the work to make it happen. Our generation 2 intake adapter is now lighter and made of aluminum, weighing in at 4.5 ounces (128 g). Custom thin-wall piping had to be fabricated, and then worked by pressing processes and hand-forming techniques to create the smooth transition. The CNC machined flange is then TIG welded to the pipe.
Note that changing from the stock airbox to our adapter will require custom mounting to structurally support the AFM, as the stock airbox is what the AFM mounts to. A heat shield or air box is recommended to keep the hot radiator air away from the inlet. We offer a complete intake kit here.
Gasket included with each intake adapter. Not for turbo applications.
Overall length: 2.75 inches (7.0 cm)
Inlet outer diameter: 2.5 inches (6.4 cm)
We like using Afe cone filter element (part number 24-25505) with this intake adapter, but you are welcome to use whichever filter element you like.
Applicable vehicles: BMW 318i/iS (E30 1989-1995), 318ti (E36 1992-1995), 318iC (E30 1991-1992; E36 1996-2000), 325e (E30 1985-1988), 325i/iS/iC (E30 1985-1991), 325iX (E30 1985-1990), 525i (E34 1989-1990), 528e (E28 1982-1988)