Catch can / AOS for Turbo

[scarfo]

im also running the crawford aos, 10,000km's now with no issues and no oil in the intake tubing

[wbradley]

Originally Posted by Northwest86

You don't have to but it is good insurance. If the PCV is working it doesn't need it.

I am confused, sort of.

Running a Cusco catch can and installed it before going FI. Thought the instructions in Japanese might be wrong and ignored the pictures showing hook up to crankcase vent. Attached to PCV instead.

It collects very little oil.

Should I be getting a lot more oil from the CCV?

Edit:

Just checked my throttle body this morning and it's dry as a bone.

[Northwest86]

With my experience the Crankcase vent produces more vapours in a FI build and can be a little more difficult to see depending on where it vents to in the intake stream. I can only speak from my street and track use.

[xkalelx]

Originally Posted by Northwest86

With my experience the Crankcase vent produces more vapours in a FI build and can be a little more difficult to see depending on where it vents to in the intake stream. I can only speak from my street and track use.

That makes me really nervous because I dont think I am seeing ANY vapor or oil coming from my CCV. Im boosted with 12psi on e85. Using a big quart size can with -10AN lines. Plumbed back to the intake pre-turbo.

[xkalelx]

wtf...

[wbradley]

^^^That's not a ton.

Where do you have the lines re-entering the intake?

I have the can re-entering from the PCV to the intake manifold where the original rubber tube went from the PCV.

The stock crankcase tube re-enters the intake just past the MAF. If that's how you have everything routed that would indicate the crankcase vent catch can isn't catching all of it.

My throttle body looking so clean indicates little/nothing getting thru. Maybe due to low miles (~22500), thicker oil (0W-40) and or my piston rings holding up well and letting thru less blow by.

I am running 8.5 Lbs max boost but very few miles since FI as I had to remove the blower all last year, so total maybe 1000 mi on it. The true test will be track days next year.

[xkalelx]

Best image I can find ATM. Return lines are roughly 6" from turbo inlet on the intake pipe.

PCV can is by the battery, CCV can is under the turbo.

Thats good news then that you arent seeing any indications. Interested in more feedback after track season.

[Efferalgan]

Originally Posted by killboy

We run Crawford AOS on both our AVO turbo BRZ (14psi) and Cosworth supercharged FRS. (6psi) With no issues. You do have to install a check valve once you are boosted though.

Then could you please answer a simple question: how, via which hose, this thing returns the caught oil to the engine? Through the PCV apparently? But PCV is there to prevent anything from re-entering the engine, right?

[Amputechture]

I was running a Crawford AOS in N/A form. Been running a JDL kit for a month now...had some issues with an incorrectly setup wastegate, along with unsecured EVAP hoses causing boost leak. In the midst of trying to find out what my problem was, I deleted the AOS at the advice of my tuner and JDL implored me to cap off my intake manifold plenum and let the PCV just vent. For some reason the car just feels like it does not breathe as well as it was prior to having the pcv set up as intended by Subaru...but it could just be me being paranoid. Where are people putting a check valve in their AOS units?

[VABeachBRZ]

I'm in the same boat. I recently purchased a SC kit and do not know if a catch can is needed.

[ShadowReaper]

Originally Posted by R2RO

I run a Radium PCV catch can, it works like a charm on my JDL Turbo kit.

Just a heads up when my car was N/A after 15k miles the catch can would fill up like 30% with blow by oil and unspent fuel.

After I went turbo the catch can fills up to 30% in only 5k miles, I would highly recommend a Radium PCV one. You can hold off on the Crankcase one, I don't find it as necessary for our cars but it wouldn't hurt to have it.

The catch can is by the battery.

Just to verify this is just one catch can correct. I see a lot of people recommend dual catch cans but if one works then whats all the hype about. I'm actually getting the same kit, and this looks to be a cheaper option than running duals.

[DAEMANO]

Originally Posted by VABeachBRZ

I'm in the same boat. I recently purchased a SC kit and do not know if a catch can is needed.

Take a look inside your intake, if there is oil or blowby type fluid in there. You need a catch can on the PCV side with a check valve. It's cheap, and will trap most of that before it re-enters your engine.

The reason why not everyone has the same result is that each engine seals differently when cold & warm. It's on a case by case basis, but I'd say it's such an inexpensive item to add (in relation to the cost of all F.I. kits) that every boosted car should probably have one as a precaution.

The image posted above (i've posted again below) shows what this looks like. It's not a lot, but would likely be trapped by a baffled catch can.

[stevo585]

Or you could save your money and just vent to atmosphere on both sides???

That's what I do...not sure if any downsides other than smell/emissions.

[dchan8]

Originally Posted by R2RO

I run a Radium PCV catch can, it works like a charm on my JDL Turbo kit.

Just a heads up when my car was N/A after 15k miles the catch can would fill up like 30% with blow by oil and unspent fuel.

After I went turbo the catch can fills up to 30% in only 5k miles, I would highly recommend a Radium PCV one. You can hold off on the Crankcase one, I don't find it as necessary for our cars but it wouldn't hurt to have it.

The catch can is by the battery.

Thanks - this information is so helpful. I will just install a catch can on the PVC side.