Killer B Air Oil Separator for Subaru 15-21 WRX FA20DIT - FA-MV3S-CAfter years of being asked to develop a Killer B Motorsport Air Oil Separator, we are proud to announce we have released the FA20 WRX Air Oil Separator. This is a product weve been asked to develop for many years, and in that time there has been a lot of research, engineering, simulations, development, testing (and repeat), with several Subaru engines and build types. This has been going on over many seasons, exposing to environmental extremes, and