This 3MI Racing drain hose kit is a game - changer for your Subaru WRX (2002 - 2014) and STI (2004 - 2021). It's a direct fit for KillerB or Verus AOS systems, though other AOS setups might need extra parts for installation.
Many regular drain hoses are nearly horizontal or have a small vertical angle. When you accelerate, this stops oil from flowing back to the sump freely. EJ engines also push oil into the heads during sharp turns, leading to too much oil in the AOS. This kit solves these problems by replacing the turbo drain hose. The return point is about 4 inches lower, which improves oil return in all driving conditions, letting your AOS work at its best.
The hose is made of wrapped silicone with nylon reinforcement and a fluorosilicone (FVMQ) liner, so it lasts a long time when in contact with oil. It comes with an extra - long turbo oil drain hose for rotated turbo kits and is marked for cutting for stock - location turbos. The 24 - inch AOS drain hose fits all common AOS install spots, and you can just cut it to the right length. It also includes new stainless hose clips for the turbo drain hose and an aluminized - fiberglass heat sleeve to protect the AOS drain from hot exhaust.
In track tests, the AOS often acted like an 'oil capacitor', only draining when braking. Secondary cans caught oil pushed from the AOS or extra oil in the vent hoses. Adding this hose helped fix these issues.
For installation, the area along the bellhousing is popular and leaves enough space for TMIC or FMIC mounts. You can also connect it in front of the uppipe, under the OEM turbo bracket.
The kit includes 1 silicone drain hose, 1 thermal sleeve, and 2 clips. Note that a single hose adapter from the 7/8 - inch block outlet to the 5/8 - inch vent hose is needed for IAG Street, IAG Comp, Cobb, and Crawford AOS systems. You can buy these adapters separately. Click here for the 3MI Racing 3/4 - inch Barbed End to 5/8 - inch Barbed End Hose Adapter.
Using the 3MI Racing AOS to EJ Turbo Drain Hose Kit is a great way to improve your Subaru's performance. First, check if your AOS system is a KillerB or Verus. If it's not, you may need to buy some extra components for installation.
When installing, you can choose to place the hose along the bellhousing, which gives plenty of space for other parts. Or you can connect it in front of the uppipe under the OEM turbo bracket. The 24 - inch AOS drain hose can be cut to the right length according to your needs.
Be aware that for IAG Street, IAG Comp, Cobb, and Crawford AOS systems, you'll need to buy a single hose adapter separately. This adapter connects the 7/8 - inch block outlet to the 5/8 - inch vent hose.
To keep your kit in good shape, regularly check the hose clips to make sure they're tight. Also, keep an eye on the heat sleeve. If it shows signs of damage, replace it as it protects the drain hose from high exhaust heat. With proper use and maintenance, this kit will serve you well and keep your AOS working effectively.
