nvr2fast

iTrader: (1)

Could someone please post a pic of which lines you are tapping exactly?

CarFanatic

iTrader: (6)

do you guys have any pictures of your 2 can set up?? I know where to tap the intake one, but not the one on the manifold. I'm also guessing the its better to have the can a shorter distance, instead of running long lines??

denial

iTrader: (27)

I'll put some pictures up but I won't be able to access them until tonight. I'd be interested to see pictures of other people's 2 can setups as well.

sleet

iTrader: (9)

I can take some pictures of my setup right now and post them up in a bit. I use to run a dual catch can like listed there but since the intake side was catching nothing I removed it and left only the PVC line. My PVC line catches a very good amount of oil, so i'll get some pictures in a few.

Also before I post the pictures, I made my own catch can that costs like $20 bucks using an air tool filter so no bashing

ShiftySVT

I'm new to turbo-charged engines so let me get this straight. In a stock setup, under normal (non-boost) operation, oil from the crankcase gets sucked up into the intake manifold, which is bad, but at least it goes directly to the intake instead of through the turbo and inter-cooler. See my picture:



This is normal for all cars and a catch can can be used to prevent this as shown.


However, in a turbo-charged car, the high intake manifold pressure under boost causes the PCV valve, which is suppose to be one-way, to leak and allow positive crank case pressure. This forces oil into the air filter box, which is bad because it gums up the whole intake track (turbo, inter-cooler, manifold) and engine. A second catch can could be used to prevent this.

What I don't understand is why the vent must be connected to the main air filter? Why not use a separate filter just for the crankcase? This would allow oil to harmlessly come out the vent filter and you could avoid using a second catch can. This way there is no way for oil to go through the turbo and inter-cooler and the regular single catch can will prevent the normal flow of oil from the crankcase to the intake. My suggestion:



The only problem I see with this is that the small amount of air that will travel through the vent and eventually into the intake will not be accounted for by the MAF sensor thus causing improper A/F mixtures. I suspect that the amount of air is so small that this probably wouldn't be an issue.

Also, it seems a couple people have noticed that a catch can in the vent tube doesn't collect hardly any oil, which indicates that the PCV leakage is minimal when it's properly functioning as a one-way valve. In this case, a single catch can between the crank and PCV valve is all that is necessary. If the PCV valve hardly leaks, then there's essentially no difference between a NA engine and a turbo engine when it comes to oil getting into the intake. NA cars run fine without a catch can, so why does a turbo charged car need one? Perhaps a small cans worth of oil going directly into the intake over the course of 5000 miles isn't all that bad.

Please let me know if I'm going wrong anywhere.

Saikou_kun

iTrader: (41)

Ok, just my 2 cents added at this point regarding some of the observations made.

I don't agree in just venting the crankcase to atmosphere because it is emissions illegal everywhere, as far as I know. When it is just vented, then there is no vacuum at any time to suck out excess oil vapor which leads to sludge built up.

Also, I have heard people saying that they don't have much oil collected in their catch cans...
well, if they are running the most common cans that don't have anything designed to condense oil vapors, that would explain why. The vapor goes in one fitting, and goes out the other one.
Of course, there is going to be a little build up, but that is simply because the can has a large interior, and some oil will condense on the walls of the can. This also means that the same amount of residue is building up in the intake.


If I am wrong about this, tell me. Anyway, this is a very good thread for discussion. I think some really good ideas are coming out of it.

MR. SNOW

iTrader: (4)

I am going to connect my catch can with two y connectors. The 1st lines will be connected to the air intake and the intake manifold. The second line with the y will be connected to the head where the lines go to the air intake and the intake manifold. Case closed. The system will pull oil into the one catch can and keep oil away from the air intake and the intake manifold. No need for two catch cans or a complicated design, only one can and four lines two y splitters.

My O2. Who has a different opinion or thinks this might be right or wrong?

ShiftySVT

That won't work. The vacuum from the intake will suck air from the filter to the catch can then directly into intake. You'll get very little crankcase ventallation because the y-connection will bypass it.

MR. SNOW

iTrader: (4)

#1)Ok, well how about if I copy the ARC design. I will plug the intke port and the y will join both sides of the head and go to the can the last line will go from the can to the air intake.

#2)Or I can do the oppisite, the two lines can be used to still connect to the catch can and the line leaving the catch can can connect to the intake manifold. Leaving the air intake plugged.

What idea is better due to vacume pressure, or lack of vacume pressure?

PA-silver03evo

iTrader: (7)

nice write up!

Saikou_kun

iTrader: (41)

OK, at this point, I totally agree with your logic.

One can keeps oil residue out of the intake side to prevent carbon build-up and sludge build up.

Another can keeps oil out of the turbo and intercooler because under high boost the PCV could leak and create vacuum on the breather hose side which would draw out oil vapors from the valve cover into the turbo.

This makes sense. Anybody wanna double check this ?

MR. SNOW

iTrader: (4)

Still no response to the one catch can Idea like the ARC design?

EvoDan2004

iTrader: (94)

OK SO WHAT SHOULD I DO??? i have mine set up like this.


there are to nipples coming out of the valve cover. one is in the back left. pvc and the other is on the right side vent. i have 1 catch can and it gos from the right side vent to the catch can then to the intake pipe.


now for my pvc valve i have a hose running from the pvc valve to the atmostphere and i caped off the intake manifold where the pvc used to hook up.

am i ok or what should i do. thanks

Saikou_kun

iTrader: (41)

When you say "copy" do you mean you are making your own?

IMO I wouldn't change the OEM setup, what I think is needed, and what the other people have suggested is adding a functional catch can to each of the lines.

again, IMO I don't like the idea of plugging up holes, venting to atmosphere, or joining the 2 lines with a y-connector etc.

The OEM setup works, it has been engineered. It can be improved by reducing the contamination of oil in the system by the addition of an oil catch can...in EACH of the lines.

I hope this helps.

I saw a picture somewhere that I think really helps with this... I will try and find it.

ShiftySVT

That's definitely the wrong way to hook it up. The PCV (not PVC) valve should never run to the atmosphere. Look at the drawings and try to understand what is going on before you ruin your engine with sludge build up.