Cobb Tuning Air Oil Separator (AOS)
The Cobb Tuning Air Oil Separator (AOS) is positioned within the Subaru crankcase ventilation system to prevent oil vapor from entering the intake system. The Cobb Tuning AOS was developed in partnership with IAG Performance and offers unique features.
Subaru EJ engines have three ports for venting crankcase pressure: one on each cylinder head and one on top of the block. Each engine vent port receives its own dedicated connection to the AOS. By providing each engine port with its own dedicated inlet to the AOS, crankcase pressure can be evacuated more effectively and quickly. Furthermore, this reduces overall system pressure. The AOS, measuring 4 inches in outer diameter and 5.75 inches in height, has a holding capacity of approximately 1 liter. A larger AOS allows you to safely generate more power without worrying about overfilling the AOS.
The bottom of the AOS is snail-shaped, directing positive crank pressure into the same swirling pattern created by the three side ports. This maximizes oil drainage while separating oil from air at all vent ports. The back plate of the AOS features a unique coolant routing system that heats the entire AOS to the same temperature as the engine. This maximizes the evaporation of water that collects inside the can. When the AOS is hot, less water collects inside and mixes with the oil.
Features
- Billet aluminum tank design
- Custom Cobb Tuning anodized cap
- Wrinkle black powder-coated canister
- Laser-etched Cobb Tuning logo
- Developed in partnership with IAG Performance
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Applications
- 2015-2020 Subaru WRX STI
- 2008-2014 Subaru Impreza WRX
- 2008-2014 Subaru Impreza WRX STI
What's in the box?
- 1 - Cobb AOS
- Hoses and hose fittings
- Mounting bracket and mounting hardware
References
Warranty
- Manufacturer Warranty
Before You Order
〇 Regarding Import Taxes
At Shaftoya Shopping Site, we pay the import taxes incurred during importation on your behalf, so you will not be charged any additional fees beyond the total amount paid at checkout.
〇 Checking Compatibility
Our entire product database is based on North American vehicles (USDM), so please check whether installation is possible on Japanese vehicles (JDM) before ordering. (If you are unsure if the listed product is compatible with your vehicle, please feel free to contact us. Our support team will investigate for you.)
If you place an order without confirming compatibility, we cannot accept returns due to incompatibility.
Please note that even if products are sorted by selecting the year, manufacturer, and vehicle model on the tabs of our home page, this does not necessarily mean they will fit Japanese model vehicles without modification.
All products have been translated into Japanese using translation software. There may be confusing expressions, so please contact us before ordering if you have any questions.
○ Regarding Delivery
Shipping costs are paid at the time of settlement. Shipping cost estimates are automatically calculated when you enter your shipping address on the checkout page. For large items such as body parts, there may occasionally be a significant discrepancy between the automatically calculated shipping cost and the actual shipping cost. In such cases, we will contact you individually by email.
All products are generally shipped internationally from our U.S. warehouse. Unlike domestic delivery within Japan, international delivery takes about 7 to 14 days, so please order with enough time. If you are in a hurry, please contact us in advance to confirm the delivery date. Please note that all products are transported by air; they will not be shipped by sea.
○ Regarding Compliance with Japanese Vehicle Inspection (Shaken)
All products we handle are basically designed and manufactured outside of Japan. Please note that they do not comply with the "Japanese Vehicle Inspection System" at all, and we cannot provide strength calculation documents or similar items for the Japanese inspection system. Therefore, all parts are sold for the purpose of "use on circuits, private property, or off-road," and installation and use are at your own risk.
○ Regarding Warranty
Please check the contents immediately upon arrival. Since all products are shipped internationally from outside Japan, there may be shipping damage to the packing boxes or the products themselves. Please understand that we will only provide returns, refunds, or replacement support if you contact us within 7 days of receipt regarding products with shipping damage, defective products, or products different from your order. Furthermore, for products sold through our company, warranty-related support will be provided "only through our company." Please note that we do not provide support through other companies or distributors located within Japan.