Radium Engineering 2015+ Subaru STi Air Oil Separator-Return Kit 2015+ WRX Cooling Designed with industry first “B-Tube”

Designed with industry first “B-Tube” technology

NOTE: If operated in freezing environments

The outlet (side port) of the AOS is plumbed back to the turbo inlet pipe

Excess oil saturated air circulating back into the air intake stream can lead to degraded performance by depositing oil on the inside of the induction system

Their designs result in an excellent free-flow exhaust system with optimized back pressure

Radium Engineering 2015+ Subaru STi Air Oil Separator-Return Kit 2015+ WRX Cooling Designed with industry first “B-Tube”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 "R"