Perrin Performance has released their Air Oil Separator for the Subaru WRX/STI. The AOS increases intercooler efficiency by reducing the amount of oil deposited into your intercooler and intake system! As blow-by/oil builds up inside your intercooler, it becomes less efficient due to less heat being transferred away from your engine. This leads to power loss and detonation, which can be damaging to your engine.


Reduce Carbon Buildup


Crank case blow-by is recirculated back to the intake to be ingested by the engine, but in doing so, gets stuck in the intake tract, intake valves, and the intercooler. This builds up over time that causes a loss in power and extra wear and tear on your valves. Reduce carbon buildup in the combustion chamber, intake valves, and in your intake tract.


Not a Catch Can


The Perrin Air Oil Separator is not a catch can. Catch cans capture water and oil vapor filling with a sticky mess requiring it to be emptied. The PERRIN AOS separates engine oil from water vapor and allows it to drain back into the engine. Oil entering from the crankcase vents spins counter clockwise through the entire body of the AOS, passing along four walls equaling roughly 50.25 sq/in of surface area. The multiple baffle walls in their compact design simulate the surface area of an AOS that is 13.5" tall.

As oil accumulates on all the walls, gravity pulls it to the bottom of the can where it drains back to the engine block while water vapor and air merge with the intake air and are re-burned in the engine. This means little maintenance or upkeep.


Heated by Coolant


The base plate of the AOS is heated by coolant drawn from the engine. By keeping the AOS the same temperature as the engine and blow-by gases, water condensation is decreased allowing oil and water vapor to separate and pass through the can.


This vital feature eliminates nearly all the sludge that can build up in the AOS body, which drastically reduce how often it must be cleaned.


Product Fitment:

• PSP-ENG-605BK = 02-07 WRX/STI with TMIC : Black

• PSP-ENG-605RD = 02-07 WRX/STI with TMIC : Red

• PSP-ENG-606BK = 08-14 WRX/08-16 STI with TMIC : Black

• PSP-ENG-606RD = 08-14 WRX/08-16 STI with TMIC : Red

• PSP-ENG-607BK = 02-14 WRX/02-16 STI with FMIC : Black

• PSP-ENG-607RD = 02-14 WRX/02-16 STI with FMIC : Red

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PERRIN PERFORMANCE AIR OIL SEPARATOR: 2002-2016 SUBARU WRX/STI

  • Brand: Perrin
  • Product Code: PSP-ENG-605xx
  • Availability: In Stock
  • $396.00
  • $374.00


Available Options


Tags: PERRIN, PERFORMANCE, AIR, OIL, SEPARATOR, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, SUBARU, WRX, STI