This kit is compatible with the 2015+ Subaru WRX and 2014+ Subaru Forester XT with the FA20F engine (left-hand drive models only).
Not for use in climates that experience extreme cold temperatures!
High-powered modified Subaru engines tend to generate excessive blow-by oil and gasses. In these cases, an ordinary small catch can may quickly fill with oil and not be adequate. Like the Radium Engineering Subaru Dual Catch Can Kit, the AOS (Air Oil Separator) kit is responsible for keeping blow-by oil and other pollutants out of the intake pipe, manifold, turbocharger, and intercooler during all engine loads. The main difference is that an AOS system returns what is collected back into the oil pan so there is no servicing required. The built-in heater keep water from condensing in the AOS, making sure ONLY oil is returned back to the oil pan, not a milky sludge.
The AOS is constructed of CNC machined sections that screw together and are sealed with O-rings. The AOS can be completely disassembled for cleaning or servicing.
-Effectively raises the fuel octane and increases engine performance with cleaner inlet air
-Prevents oil buildup in the intake or intercooler system walls, throttle body, intake manifold, etc.
-Lowers hydrocarbon emissions
2015+ Subaru WRX Installation
The Radium Engineering AOS kit installs on the LH side of the engine bay, near the brake master cylinder. The outlet (side port) of the AOS is plumbed back to the turbo inlet pipe, creating a completely sealed system.
-Machined aluminum Radium Engineering Air/Oil Separator
-Specially designed mounting bracket
-All necessary SAE J30R7 rated PCV/Emissions hose
-Coolant hoses and fittings
-PCV delete fitting
-All necessary aluminum fittings and hose-ends
-Stainless steel mounting hardware
-20-0255 Master Cylinder Brace (20-0258-00 only)