Perrin Subaru WRX/STI (08-13) Air Oil Separator Kit- LHD Models Only

Increase Intercooler Efficiency

The AOS increases intercooler efficiency by reducing the amount of oil deposited into yPerrin's intercooler and intake system! As blow-by/oil builds up inside yPerrin's intercooler, the less efficient it becomes due to less heat being transferred away from yPerrin's engine. This leads to power loss and detonation, which can be damaging to yPerrin's engine.

Reduce Carbon Buildup

Reduce carbon build up in the combustion chamber, intake valves, and in yPerrin's intake tract. 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 which causes a loss in power and extra wear and tear on yPerrin's valves.

Reduce Detonation

The octane level of oil is very low. Anytime there is a significant amount of engine blow-by (oil) being put back into yPerrin's engine, it reduces yPerrin's fuel's octane level leading to detonation or knock, which will cause loss of power and engine failure.

PCV System Included

We designed the PERRIN Air Oil Separator kit based on the idea that using a PCV on the AOS outlet ensures proper crank case venting during light loads and helps reduce unwanted blow-by gases into yPerrin's intake system. Incorporating a PCV reduces the smell from exhaust and keeps yPerrin's intake tract clean.

Easy Disassembly For Cleaning

Over the years, a slight buildup may occur inside yPerrin's AOS. This can be quickly taken care of by removing one bolt to access the inside for cleaning. This small feature is one of the many things that makes the PERRIN AOS stand out from the rest.

Swirl Pot Technology

Featuring swirl pot type technology and multi-layer baffles, the PERRIN Air Oil Separator forces incoming air to circulate across the baffles, separating oil from engine blow-by.

This is 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 fPerrin's walls equaling roughly 50.25 sq/in of surface area. The multiple baffle walls in Perrin's 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.

Custom Drain Back Fitting

Instead of using a universal type fitting, we have designed a purpose built crank case fitting that does the job perfectly. Like the AOS body, the drain fitting is threaded to except virtually any kind of fitting to allow for easy customization on special projects.

Heated By Coolant

The base plate of the 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 you must clean it.

Hardware and Parts

Every connection on the PERRIN AOS is threaded NPT which is a very universal way to connect fittings. This allows for totally customizable setups and installations to be done, to best match yPerrin's setup.

Application Specific Mounting Brackets

Each kit comes with specific mounting brackets and instructions to install yPerrin's AOS perfectly in yPerrin's engine bay or adapt Perrin's simple 2-hole mounting bracket for custom installations.

Finish

Powder coated for protection against the elements, the textured finish will look awesome for years to come. The PERRIN AOS is available in black or red texture powder coating.