The Grimmspeed Air-Oil Separator (AOS) is one of RallySport Direct's highly sought after items. Grimspeed uses a unique patent pending design which allows you to maintain your PCV valve while separating oil from the air in both the heads and crankcase. These boxer engines have inherent issues with harmful oil and vapors getting into the intake system of your vehicle which can cause issues like having an effect on the octane rating with your gas, and after long periods of use and mileage can cause buildup on your valves.

This particular air-oil separator takes the place of an oil catch can, or a tank which is convenient to eliminate the need to empty the catch can. This is a subtle installation that replaces your factory oil filler cap.

New lines, fittings, and zip ties will be included to make this catch can system ready for the installation. 

Note that this particular unit will come in the anodized black finish for protection against corrosion, and to add a nice touch to the theme of your engine bay.

APPLICATIONS:

Subaru WRX 2002-2007 / STI 2004+