3MI Racing LLC

12/24/2025

So these OEM Location Turbo drain hose kits were quietly released a few months back to our retailers and installers. This AOS drainhose kit is designed as an OEM location specific kit to remove the fear and measuring that comes with using our universal kit, particularly for first-time time installers.

We still sell our universal kit (long hose) for people with rotated turbos. We also have several Subaru specialty shops stock them as an easy upgrade to keep on hand to go along with AOS installs, or to upgrade an AOS during a turbo upgrade. "Would you like fries with that?"

Please reach out to our retailers for purchase; Flatirons Tuning Import Image Racing or Penguin Garage

Specialty shops can inquire directly for jobber/wholesale pricing.

05/31/2024

02/29/2024

Thanks to Flatirons Tuning for being so fantastic to work with. Give the video a look and a like. Check out the other Subaru content they've put together while over on their page.

The 3MI Air Oil Separator for most Subaru AOS's came out a while back, and we have been recommending it to maximize the effectiveness of your AOS.

08/27/2023

Man, I am terrible about posting on here!!

So the AOS Drain Hose kits have been released for about 18 months now and they have gained great feedback from users.

TLDR; it helps keep your oil where it belongs, in the sump and not your AOS system.

They allow the AOS to more efficiently drain through the turbo oil drain, and not TRY to drain into the crankcase vent. This actually replaces the turbo drain hose in the system and allows the crankcase breather to vent unhindered.

We have adapter kits to allow them to fit most popular AOS kits foe your turbo EJ engine.

Check them out , or

08/10/2023

Our friends over at Import Image Racing are now stocked up on our AOS drain hose kits. Head on over to them to help get your AOS working better than ever!!

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...

12/24/2021

And our friends at Penguin Garage has AOS kits in stock now as well. Time to get that oil back to where it belongs!

3MI AOS Oil Drain hoses in stock and on the website. I know I’ve got at least 4 of the 10 pre-sold. If you want one message us or schedule an appointment.

12/23/2021

Our friends over at Flatirons Tuning have put together a nice writeup on our new AOS oil drain hoses. Go give it a read and let us know what you think!

Air Oil Separators are pretty common these days on modified Subaru's. There are a number of different options out there, but when installing them, there is one common factor that you have to take into consideration. That is the drain hose. Every AOS that we have seen as of writing this uses

12/09/2021

New Product Alert!

Put simply this hose is used to improve the oil return from your AOS so that it can better perform for you.

So what's going on?
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.

Testing
In track testing we found that the AOSs 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.

The Fix
This hose replaces the turbo drain hose allowing the return point to be 4"-5" lower and improve oil return in all conditions. This allows your AOS to do its job better.

The Hose Kit ($65)
- 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 with an extra long turbo oil drain hose for use with rotated turbo kits as well. The drain hose is marked for cutting for stock location turbos.
-It features a 24" AOS drain hose to fit all common AOS install locations. Simply cut to length.
-It includes new stainless hose clips for the turbo drain hose
-An aluminized-fiberglass heat sleeve is included to help protect the AOS drain section from high exhaust heat.
Separate Hardware kits are required for installation of certain common AOS systems.

KillerBee and Verus: The hose kit alone is all that is needed.

IAG Street, IAG Comp, Cobb and Crawford: A single hose adapter from the 7/8" block outlet to the 5/8" vent hose. ($10)

Perrin: Requires a 7/8" block outlet to a 1/2" vent hose adapter, and then also a 1/8"NPT to 1/2" barbed 90* fitting for oil drain back. ($15)
Attached are few pictures of various installation options. Along the bellhousing seems the most popular and leaves plenty or room for TMIC or FMIC mounted locations. Reverse mount (you can see coming up by the turbo compressor outlet). You can also plumb it in front of the uppipe.

08/03/2021

We have several sets of Subaru Lower Intake Manifold Housings. These are new parts, but have cosmetic blemishes.

The blemishes range from damage from tooling and/or mishandling, while others had signs of porosity at the bottom side of the injector. Please see pictures for examples. These parts are completely functional.

MSRP for these is $229, so we're knocking $60 off each set.

These are a lightweight replacement for Subaru PN 14001AB370 or 14003AB930 only if converting to top feed injectors. These are housings for engines that came without TGVs.

The housings have a few features that a typical housing won't have:
- a hard anodized center "nut-plate" that can be flipped around to be used with cable and drive-by-wire intake manifolds
- the outer bolt columns were deleted to allow more room for larger aftermarket turbo inlets
- we left a gap between the center columns to save some weight while also allowing potential routing options for hoses and harnesses

We include lower gaskets and new stainless steel hardware with each set.

05/20/2021

The RPM Act is being put forward again.
Please take 60 seconds to send a letter to your congressman to grab support and keep our industry and race cars alive and legal.

SEMA’s & PRI’s top federal legislative priority is passing the RPM Act. We are currently working with the RPM Act’s strongest supporters in Congress to identify the best strategy for reintroducing the bill in a way that maximizes its chances of becoming law, either...

04/08/2021

Been toying with bringing another 132.5mm ("+2") rod to the market. I've never kept 132.5mm rod with 23mm pins as a OTS part.

This was spurred from the discussion we had on the Flatirons Tuning podcast (see link in the first comment).

What are you thoughts? Does anyone even build their own engines anymore or just buy off-the-shelf from whoever has a block ready?

03/06/2021

It's a lovely day to watch some RACING!!!!
If the live stream is dead, check their page and you'll see the latest live session.

LIVE! from COTA - Super Lap Battle Day 1 Session 2