Description
The AEM 21-863WR combines a mandrel-bent aluminum intake tube, reusable Dryflow filter and custom heat shield for supported WRX STI 2.5L applications. The factory fresh-air duct attaches to the shield to supply the filter area.
Design and operation
The formed tube and conical filter replace the factory intake arrangement as a matched system. The heat shield helps separate the filter from nearby engine-bay heat. This part must be identified by its full WR suffix when comparing it with the 21-863C.
Key specifications
- Manufacturer part number: 21-863WR
- Aluminum tube; custom heat shield with factory fresh-air duct connection.
- Washable, reusable, oil-free synthetic Dryflow filter.
- Replacement filter: 21-2157DK.
Installation and compatibility
Confirm the exact STI year and required tube finish before ordering. The listing identifies Wrinkle Red, but current manufacturer specification data conflicts on finish; finish requires confirmation for part 21-863WR. Follow the installation instructions and confirm calibration compatibility with the vehicle’s existing modifications.
Maintenance
Inspect the filter according to dust exposure and use. Clean it with a cleaner suitable for the Dryflow media, allow it to dry fully and do not apply filter oil. Check clamps and connections during routine servicing.
Important application notes
Finish information requires confirmation: the catalog identifies Wrinkle Red while current manufacturer specifications list gunmetal gray. Verify the supplied finish before ordering. Emissions eligibility is application-specific.
Vehicle fitment
The following catalog applications include trim-specific year ranges. Confirm the exact vehicle before ordering; listed fitment does not by itself establish emissions approval.
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2019-2021 | Subaru | WRX STI | Base |
| 2019-2021 | Subaru | WRX STI | Limited |
| 2019 | Subaru | WRX STI | S209 |