The Subaru FA engine has 2 ports that vent crank pressure: two at 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 we have allowed for more effective and faster excavation of crankcase pressure. Additionally, this reduces overall system pressure. With a 4" OD and 5.75" height, the AOS has an approximate 1 liter of holding capacity. The larger the AOS, the more power you can safely make without having to worry about the AOS overfilling.
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 9 mounting holes enable the breathing port a full 180° of rotation. On the bottom, 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. The bottom of the AOS is shaped like a snail, redirecting positive crank pressure into the same swirl pattern produced by the 3 side ports. Allowing maximum oil drainage while separating oil from the air in all the venting ports. The back plate of the AOS features a unique coolant routing system that heats the entire AOS to the same temperature of the engine. This maximizes the evaporation of any water collecting inside of the can. The hotter the AOS, the less water will collect inside and mix with the oil.
The AOS arrives completely assembled and ready for immediate installation. However, the entire unit can be broken down for cleaning. With a single allen wrench, you can remove 4 bolts and the AOS easily separates into individual pieces. The AOS drain port is able to be rotated for ease of installation. All fittings supplied with the AOS are anodized aluminum and feature Viton sealed ORB fittings. The supplied coolant hose is built to SAE 20R3 standards. It will withstand coolant temperatures of +257°F. The oil vapor hose is designed to withstand oil and fuel vapors, exceeding SAE J30R7 standards. The center bracket allows for adjustable mounting. If your engine bay changes, you can easily change how and where you mount the AOS. A single laser-cut mounting bracket is included that fits nearly all applications and configurations. A laser cut harness relocation bracket is also included. The bracket allows the engine harness connector to be moved forward for additional clearance.
- AOS Top - Dual Breather Port Rotation For Install Ease
- AOS Top - Greater Pressure Stream Oil Separation
- AOS Body - Large Billet Aluminum Design
- AOS Body - Various Powdercoat Finishes Available
- AOS Body - Approximate 1 Liter Holding Capacity
- AOS Body - Integrated 3 Port Billet Hose Barbs
- AOS Bottom - Unique Baffling Controls Crankcase Pressure
- AOS Bottom - Returns Oil To The Engine
- AOS Bottom - No Maintenance or Manual Draining Required
- Ready to Install - Includes Hardware, Lines, and Fittings
NOTE: IAG recommends the STREET SERIES AOS for ALL cars running E85 or high-ethanol fuel blends
In stock, non special order items can be returned within 30 days of the product arriving to your house or place of work.
Returns will NOT be accepted on final sales, special orders, opened, installed, incomplete, or otherwise used products. In order to initiate a return, an RMA number must be requested and approved via e-mail.
All returns will be subject to a 20% restocking fee minus complete shipping cost (roundtrip).
Any processed orders that have not shipped will incur a 6% cancelation refund fee unless the product was not available to ship within a timely manner. No fee will be incurred if used as store credit.
For complete details on our return policy, please see our Help and FAQ link under HELPFUL INFO.