3MI Racing AOS Oil Return Hose Kit Install "Short Kit" Subaru WRX 02-14 / STI 04-21 | 3MI00125017

Fitment Information:

• 2002-2014 Subaru WRX
• 2004-2021 Subaru STI

Please note: This kit is a direct fit for your KillerB or Verus AOS system. Other AOS systems may require additional components for the installation.

Features:

Many drain hose installations have the drain hose close to horizontal or with very little vertical angle. Under acceleration this prevents the oil from freely draining back to your sump. It is also well documented that EJ engines, under heavy cornering, push oil into the heads and can lead to excess oil entering the AOS. Additionally, this eases installation of the drain hose as many times it is inadvertently installed incorrectly by people who do not have experience.

The 3MI Racing Drain Hose Kit has been designed to replace the turbo drain hose allowing the return point to be around 4 inches lower and improve oil return in all conditions. This allows your AOS to do its job better.

• The hose is constructed of wrapped silicone with nylon reinforcement, with a fluorosilicone (FVMQ) liner to have a long life interacting with oil. -lt comes cut to length to install with stock location turbos.

• It features a 24" AOS drain hose to fit all common AOS install locations. Simply cut to length.

• It includes a new stainless hose clip (for the upper/turbo side) and a smooth band hose clamp (for the lower/cylinder head side).

• An aluminized-fiberglass heat sleeve is included to help protect the AOS drain section from high exhaust heat.

In track testing we found that the AOS's were acting more as an "oil capacitor" only really draining under braking. In testing we had secondary cans catching oil being pushed from the AOS and/or excess oil found in the vent hoses. We suspect most of this was due to the AOS designs having more oil in the can than designed for. The addition of the hose helped alleviate these issues.

Installation notes:

• Along the bellhousing seems the most popular and leaves plenty or room for TMIC or FMIC mounted locations.

• You can also plumb it in front of the uppipe, under the OEM turbo bracket.

• Please note that if you don’t have heat shielding on your uppipe, you might require an additional heat sleeve on the turbocharger to cylinder head section. Exposure to prolonged high temperatures can break down the material and allow oil to permeate through it. 

What's Included in this Kit:

• (1) Silicone Drain Hose

• (1) Thermal Sleeve

• (1) Stainless Steel Spring Clip

• (1) Stainless Steel, Smooth Band, Hose Clamp

Please note: A single hose adapter from the 7/8" inch block outlet to the 5/8" inch vent hose is required for the installation of the IAG Street, IAG Comp, Cobb and Crawford AOS systems. Perrin’s AOS requires an adapter kit that includes a hose barb adapter (block side) and NPT to ½” barb adapter (threads onto AOS). These are available to purchase separately.