COBB Tuning Air/Oil Separator (Part #822615)

The COBB Tuning Air/Oil Separator (AOS) is engineered to optimize the crankcase ventilation system in your Subaru, effectively preventing oil vapors from contaminating the intake system. This product has been developed in collaboration with IAG Performance, ensuring high-quality construction and performance enhancements.

Key Features

• 1 Liter Holding Capacity: Adequate volume to handle crankcase pressure without the risk of overfilling.
• Integrated ORB Ports: Designed to facilitate easier connections and improved airflow.
• Compact Cast Aluminum Body: Finished with a sleek black powder coat for durability and aesthetics.
• Heat Shielding: Protects crankcase breather and oil return lines from excessive heat.
• Coolant Bleeder Valve: Allows for easy maintenance and ensures optimal performance.
• Distinctive COBB Color Combination: Enhances visual appeal under the hood.
• Laser Etched COBB Logo: Mark of quality and authenticity.

Design and Functionality

The AOS is designed with a unique snail-shaped bottom that redirects positive crank pressure into a swirl pattern, maximizing oil drainage while effectively separating oil from air across all venting ports. Each of the three engine vent ports—located on each cylinder head and the top of the block—connects directly to the AOS for rapid pressure relief and reduced overall system pressure.

With dimensions of 4 inches in diameter and a height of 5.75 inches, the AOS’s capacity allows for increased power potential without the concern of oil vapor recirculation. The back plate features a coolant routing system that maintains the AOS at engine temperature, promoting evaporation of any moisture that could mix with oil.

Impact on Performance

By preventing crankcase oil vapors from re-entering the intake system, the COBB AOS helps maintain the effective octane rating of your fuel while mitigating oil and carbon buildup over time. This is particularly beneficial for high-performance applications where maintaining engine cleanliness is crucial.

Confirmed Fitment

• Subaru Legacy GT AT USDM 2005-2009
• Subaru Legacy GT MT USDM 2005-2009
• Subaru Legacy GT Spec B MT USDM 2006-2009
• Subaru Outback XT AT USDM 2005-2009
• Subaru Outback XT MT USDM 2005-2009
• Subaru Impreza STi Hatch MT USDM 2008-2014
• Subaru Impreza WRX Hatch AT USDM 2008
• Subaru Impreza WRX Hatch MT USDM 2008-2014
• Subaru Impreza WRX Sedan AT USDM 2008
• Subaru Impreza WRX Sedan MT USDM 2008-2014
• Subaru Impreza 2.5 GT Hatch AT USDM 2009-2010
• Subaru Impreza 2.5 GT Sedan AT USDM 2009-2010
• Subaru Impreza STi Sedan MT USDM 2011-2014
• Subaru Forester XT AT USDM 2009-2013
• Subaru WRX STI Sedan MT USDM 2015-2021
• Subaru WRX STI Type RA Sedan MT USDM 2018
• Subaru WRX STI S209 Sedan MT USDM 2019

Installation Notes

For detailed installation instructions, please refer to the official documentation: CLICK HERE.