IAG Air / Oil Separator (AOS)
The IAG Performance V3 Street Series Air / Oil separator (AOS) is an excellent investment to keep your Subaru vehicle running well. The Street Series AOS maintains OEM PCV system functionality, but supplements its capacity. The Street Series AOS design is based on years of extensive testing on standard and competition applications. The Street Series AOS' large, 1-liter, cast aluminum swirl pot canister more effectively separates oil from the PCV system upstream of PCV gasses return to the intake system. The Street Series AOS' fully-heated cast aluminum housing, superior venting, and unique, patent pending, baffle design set it apart from the rest. The Street Series AOS is compatible with all fuel types, extends engine life, improves crankcase ventilation and is compatible with standard ECU calibrations.
Keeping Oil Out
Keeping oil out of the engine intake tract is extremely important towards preventing premature mechanical failure and maintaining performance. Oil in the intake tract of the engine has several detrimental effects. First, the oil coats the internal portions of the intake, intercooler, and piping. This oil may cause premature failure of rubber or silicone hoses, which leads to failed connections.
Once the oil reaches the intake tract it will directly enter the intake manifold and then the combustion chamber of the engine. Oil inside of the combustion chamber can cause detonation and preignition, high emissions, smoke, loss of power, decreased gas mileage, and even catastrophic engine failure leading to expensive repair bills.
PCV Recirculation
The Street Series AOS maintains the OEM PCV system functionality, but supplements its capacity. The Street Series AOS PCV discharge gasses return to the turbo inlet, retaining a PCV valve to draw additional suction, improving air oil separation. The Street Series AOS protects from oil dilution and lubrication failures in ethanol fueled application because the Street Series AOS captures fuel vapors out of the oil and returns these vapors to the intake tract for combustion. The Street Series AOS protects from both oil entrainment in the intake flow and oil dilution in the engine's lubrication system far better than the OEM PCV system alone.
Version 2 vs Version 3 IAG AOS
The most popular Subaru AOS is now even better! The IAG AOS body is completely redesigned using cast aluminum and features an integrated coolant passage for better heat retention. Additionally, the V3 AOS heating system is upgraded by relocating the coolant lines to the bottom of the body using new swivel fittings, heat sleeving and an integrated coolant bleeder. These heating system upgrades will allow for a cleaner installation and less condensation buildup in colder climates. The new compact body has the same 1-liter capacity as V2, but features a sleeker design and adds removable ORB fittings for greater versatility.
AOS TOP
- True 360 Degree Rotating Breather Port
- Dual Breather Ports
- Greater Pressure Stream Oil Separation
Notice the dual breather port? At first glance you might think this is excessive, however, our reasoning is grounded in simple physics. As air and particles of oil enter into the AOS, the largest particles of oil will collect on the inner surface of the can and drain to the bottom, but the smallest particles will remain suspended in the pressurized stream.
As the air makes its way through the multi-stage baffle system, gravity pulls oil from the air. By increasing the overall volume of the breather opening on the top of the AOS, we have drastically decreased the exit velocity of the crankcase vent (CCV) stream. The slower velocity leads to greater oil separation from the pressure stream. A total of 20 mounting holes enable the breathing port a full 360° of rotation. On the top, a thick Viton o-ring seals the can. Every o-ring in our AOS is formed from Viton which offers superior temperature and chemical resistance.
AOS BODY
- Compact Cast Aluminum Design
- Approximate 1 Liter Holding Capacity
- Integrated ORB Ports
- Aluminum Body is powder coated in Red or Black Wrinkle Finish
- The side of the AOS features 3 -8 ORB removable billet hose barbs.
The Subaru EJ engine has 3 ports that vent crank pressure: one on each cylinder head, and another on the top of the block. Each engine vent port receives its own connection to the AOS. By giving each engine port its own entrance to the AOS IAG has allowed for more effective and faster excavation of crankcase pressure. Additionally, this reduces overall system pressure. The AOS has an approximate 1 liter of holding capacity. The larger the AOS, the more power you can safely make in competition applications without having to worry about the AOS overfilling.
AOS BOTTOM
- Unique Baffling Controls Crankcase Pressure
- Returns Oil To The Engine
- No Maintenance or Manual Draining Required
Fitment:
Subaru WRX - 2008-2014 2.5 Turbo
Subaru STI - 2008-2021 2.5 Turbo
