i have similar setup as above. tb capped off. passenger side to intake tube. driver side to vented catch can than to the manifold. got a check valve between the can and filter, so it can only blow out and not suck in. added a filter to the oil filler too. can't vent crankcase to much.

 

Ok after reading more I understand the need for the catch can to be vented as long as there is a check valve between the filter and can so vacuum can still be applied.

I drew up two diagrams to make what im thinking of doing more visual so you can add input and advice to it.

The first one is what I think most of you are doing so both valve covers will have vacuum to them under boost and can vent when not under boost if positive pressure is present.



The second is one I have seen others do so vacuum will be present all the times. The throttle body will draw vacuum when not in boost where the turbo inlet might not (from what i have read on other forums they say not enough restriction to air flow is present pre-turbo to create vacuum until in boost.) but once in boost it will pressurize the valve covers if there isn't a check valve. Once in boost the turbo inlet will become the vacuum source.

Is this correct? Is this setup necessary or have any real benefits?

 

there are several ways to do it. you will want vacuum to be pulling fumes etc out of the crankcase even when not in boost. i use the driver side port to get my vacuum. here is basically what i have. sorry for the paint skills.

 

By going to the manifold how do you account for the unmetered air? It would have to go before the maf right?

Or are you using a sd tune?

 

Dont try and reinvent the wheel. Notice blackhmg, black04 and I are all running the same setup.

The setup works fine with a maf, same as stock.

 

Is this the setup you are running? so do you need 2 catch cans or one? This is the most confused I have ever been about anything.

 

i've been running this setup for 2 yrs now, works great. i usually drain the can every couple hundred miles. i'm in boost a lot tho. driver side is basically stock w/ vented catch can. passenger side take the line on front of the valve cover and move it to behind air filter for turbo. cap it off where you took it off the tb. the filter on the oil filler is just used for extra venting, not a have to. simple as it gets. don't make it more difficult than it is.

 

I dont know why but this just made something click in my head and i now understand how it will work. Thanks for the help!!!!

 

This is what I have been doing since day one. No issues.

 

Any suggestions of what brand catch can to get??
Also cheap check valves? a boomba 1/2" check valve is $40 just seems like a lot for that part.