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Perrin Air Oil Separator 2015-2021 WRX

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Original price $572.00
Original price $572.00 - Original price $572.00
Original price $572.00
Current price $486.20
$486.20 - $514.80
Current price $486.20
  Lease to own   Pay as low as   $/week

Availability : 9 In stock

Color: Black

The PERRIN Air Oil Separator traps oil from the crankcase vents before it enters the intake, reduces carbon build-up, increases intercooler efficiency, which reduces the chance of performance-robbing detonation.


  • NO TUNING REQUIRED - Increase horsepower and torque without ECU recalibration or tune! This part is designed and tested to work safely on your vehicle without any tuning required! However, more power can be gained with proper ECU tuning!
  • NOT A CATCH CAN - Catch cans capture engine blow-by and stores it in a container, which requires constant attention and removal of oil every few hundred miles. The air oil separates the oil from the air, draining it back to the engine, which eliminates the need for constant attention and draining of oil. As oil drains from the bottom of the Perrin AOS, clean oil-free air vents out of the top to rejoin the intake tract.
  • SWIRL POT TECHNOLOGY - The Perrin AOS features swirl pot technology and multi-layer baffles. This design forces incoming engine blow-by to move rapidly across the baffles, separating oil from the engine blow-by. Multiple layers of baffles means more surface area to collect more oil, making for a compact and efficient design. Oil entering from the crankcase vents spins counterclockwise through the entire body of the AOS, passing along four walls equally roughly 50 sq/in of surface area. The multiple baffle walls in our compact design simulate the surface area of an AOS that is 13.5" tall. 
  • HEATED BY COOLANT - The base plate of the AOS is heated by coolant drawn from the engine. This heats the entire AOS to the same temperature as the engine blow-by. By keeping the AOS the same temperature as the blow-by, water condensation is significantly decreased, allowing oil, air, and water vapor to separate and pass through the body. This vital feature eliminates nearly all the sludge that can build up in the AOS body, which is a common problem with catch cans and other AOS.