IAG + PSR RHD Performance Street Series Air/Oil Separator

New Release 2025 Updated Kit - Developed by PSR and IAG Performance to bring the best RHD suitable IAG AOS yet. Exclusive to Pro Speed Racing.

IAG x PSR: Updated AOS Kit for RHD Vehicles

(note, images still show LHD kit)

The 2024 changes to the IAG Performance Air/Oil Separator kit introduced pre-assembled hoses with new SAE Quick Connect fittings to simplify installation for LHD vehicles. Unfortunately the lengths of these hoses did not suit the RHD mounting position at all, and coupled with the already present hurdles with installing this kit on RHD vehicles it made installation much harder. This spurred PSR to work together with IAG to come up with a better solution.

The IAG x PSR kit now has the following changes to improve installation for RHD vehicles:

• No pre-assembled or pre-cut hose lengths: This allows the user to decide the best hose routing for their engine bay and cut the hoses to the appropriate length. 
• Additional hose: As the RHD mounting position is further away from where IAG designed the LHD position we have included extra hose to accommodate. 
• 5/8" Coolant Hoses. This allows installation onto the heater core coolant loop without the need for adaptors or reducers.
• Including intake manifold barb fitting: Allows the included AOS return hose to connect to the manifold without the need for hose reducer fittings.
• PSR Mounting Bracket: Allows mounting on to the passenger side strut tower and includes multiple bolt holes to allow correct positioning.

the IAG x PSR kit still includes the new 2024 updated SAE quick connect fittings which can be installed onto all hoses after they have been cut to the correct lengths, allowing for simple installation and removal of the vent hoses.

We have included RHD installation notes available beneath the instructions tab below.

SAFEGUARD YOUR SUBARU

The IAG Performance Air / Oil Separator (AOS) is a valuable investment to protect and maintain peak performance in your Subaru. Developed through years of meticulous testing on standard and competitive applications, the design of the AOS offers unparalleled protection for your engine. This AOS features a 1-liter swirl pot canister made of cast aluminum. This construction significantly enhances the separation of oil from the PCV system before the PCV gasses are directed back to the intake system.The Air Oil Separator features an aluminum housing that has superior ventilation, and it incorporates an exclusive baffle design that sets it apart from the competition. It works with all fuel types, prolongs engine lifespan, optimizes crankcase ventilation, and seamlessly integrates with standard ECU settings, so no tuning is required.

KEEPS OIL OUT OF THE INTAKE

The presence of oil within the engine's intake tract brings about a range of adverse effects, so preventing oil from entering the engine intake is crucial for avoiding premature mechanical issues and maintaining optimal performance. Initially, the oil coats the internal components of the intake, intercooler, and piping, which can potentially harm or prematurely deteriorate rubber or silicone hoses, eventually leading to compromised connections. Once the oil enters the intake tract, it has access to the intake manifold and then the engine’s combustion chamber. Oil inside the chamber has the potential to trigger detonation, pre-ignition, excessive emissions, smoke generation, power loss, reduced fuel efficiency, and in extreme cases, severe engine damage or even complete engine failure.

NO MAINTENANCE NEEDED

The IAG AOS is designed for effortless upkeep. Unlike typical catch-can systems, our Air Oil Separators operate without the need for routine draining and maintenance. Separated oil gathers on AOS can walls and slowly drains into the engine's crankcase. With the help of our unique heating system, the collected oil remains free of sludge, ensuring that there is no risk of reintroducing it into the engine. The substantial size of the AOS body allows for a safe and gradual oil drainage process, effectively removing the chance of overflow commonly observed in smaller catch cans.

HOW DOES THE AOS OPERATE? WHAT’S INSIDE?

The IAG Air / Oil Separator features a unique baffle system that captures the oil suspended in your engine's PCV gasses, which are then able to drain back into the crankcase. The AOS body's inlet hoses are set up to create an internal gas vortex, which is then filtered through a series of baffles. The baffles gather the oil while enabling the gasses to exit from the upper part of the AOS canister. As the factory PCV remains active, this allows the engine to generate a vacuum in the AOS assembly to draw out even more of the PVC gasses.

IMPROVES UPON THE OEM PCV SYSTEM WITH NEW CHECK VALVE

The AOS works with the OEM PCV system, while also providing a boost to its capacity. The AOS directs PCV gasses to the turbo inlet, using an upgraded PCV valve for additional suction and air-oil separation. For applications using ethanol fuel, the AOS provides protection against problems like oil dilution and lubrication issues. This is accomplished by capturing fuel vapors emitted from the oil and then reintroducing them into the intake tract for combustion. The AOS provides exceptional protection against oil entering the intake flow and oil dilution in the engine's lubrication system, exceeding the capabilities of the OEM PCV system alone.

MINIMIZES CONDENSATION BUILDUP

The IAG Air / Oil Separator uses a unique heating system to solve problems found in lesser catch cans. In inferior models, hot PCV gasses pass through a cold pathway, which causes condensation that mixes with the oil and causes sludge. IAG’s upgraded design attaches to the vehicle’s cooling system, allowing heat from the engine to transfer into the AOS canister. By warming the AOS canister to the engine's temperature, condensation and related buildup are greatly reduced or eliminated.

SAE QUICK CONNECTION LINES

IAG’s Air / Oil Separator includes a full set of custom length SAE Quick Connection lines that not only simplify the installation of the AOS system, but they also reduce the chance of leakage because they offer a more reliable and secure connection than basic hose clamps. Once installed, our AOS system has a clean, factory-look that integrates seamlessly with your Subaru’s engine.

Notes regarding this guide:

This guide is intended to be used in conjunction with instructions provided by the catch can/AOS kit manufacturer. This guide refers primarily to the changes to installation of these kits due to the new mounting position of the RHD PSR bracket.

Routing of hoses shown in this guide are suggestions only. Your vehicle may require different routing depending on the position of other accessories in the engine bay. While every attempt should be made to allow the drain hose to travel downwards, in our testing we have found that the AOS still drains effectively if not perfectly flat.

Installation is recommended to be performed by a qualified automotive mechanic. Vehicle malfunction or damage can occur if installation is not carried out correctly.

PSR is not liable for any problems that may arise due to improper installation.

Click to Download PSR Guide

Click to Download IAG Instructions for 18-21 STI

Click to Download IAG Instructions for 15-17 STI

Click to Download IAG Instructions for 08-14 STI

Click to Download IAG Instructions for 10-14 WRX

Click to Download IAG Instructions for 08-09 WRX