Catch Can Routing Diagram for Turbo

[SeaCompiler]

Originally Posted by fif_gen_powa

The valley plate is baffled does not flow as well as the valve cover which is free flowing

OK, so it let's air in, but restricted so it does not flow freely out the valve covers. So, if there was no restriction, then there would be no vacuum if I understand it.

Originally Posted by supergt99

i have mighy mouse catch can. i used his diagram when i had turbo and it worked fine. the diagram is on this page.

http://www.mightymousesolutions.com/#!mm-black/ca5m

Thanks. I saw that and the part I don't understand is the dotted line from the driver side back valve cover to the turbo inlet. I figure it is the inlet between the filter and the turbo - wouldn't this pull air/other from the back cover, but the arrow is showing the opposite direction going into it? I guess at idle, it can breath?

Originally Posted by Sakudog

The valley pan breather should be pulling air in at idle to help equalize and replace the air being evacuated via the valve covers & tb path.

Under boost the check valve stops air flow back into the catch can.

The valley pan is not part of the intake system. If this is getting pressurized at idle or light cruise well you've got bigger issues.

This is a street setup. I would contend that for something like road racing with extended high rpm engine operation, MightyMouse would recommend something else. In my case it has worked flawlessly.

The diagram is from MightyMouse and he has a much better way to explain how this system would work.

I would highly recommend spending the money to buy his products they are very well designed.

Sent from my iPhone

Thanks for explaining the valley pan breather, that makes sense.

Originally Posted by blake-b

I have a MM can also. He told me to run mine like this:
Each valve cover has a 10AN bung to an inlet on the can. PCV valve back to intake. I had a 10AN bung welded on the valley cover and it will "Y" to each CAI tube pre turbo. The factory valley cover port is blocked off.

For a minute, I could not figure out why you have two CAI tubes and I thought you were crazy and then I realized you must have a twin turbo setup? So under acceleration, I assumed a stronger vacuum pull is created on the inlet pre-turbo which would pull harder on the Y adapter coming from your valley plate thus possibly sucking in yucky stuff, but I guess this is not true or everyone would have catch cans there, but I forget that there will be blowby in the crankcase and there will not be some big sucking draw through the valley plate port?

[blake-b]

For a minute, I could not figure out why you have two CAI tubes and I thought you were crazy and then I realized you must have a twin turbo setup? So under acceleration, I assumed a stronger vacuum pull is created on the inlet pre-turbo which would pull harder on the Y adapter coming from your valley plate thus possibly sucking in yucky stuff, but I guess this is not true or everyone would have catch cans there, but I forget that there will be blowby in the crankcase and there will not be some big sucking draw through the valley plate port?

Regardless of whether I have twin turbos or not (I do), my wife is convinced I am crazy because of the car...

Yes, there will be a vacuum pulling from the valley (because of the suction from the turbos) in addition to the pressure from within the crankcase itself pushing itself out into the line going to the CAIs.

In the picture of the valley cover below, the black plastic piece is a baffle basically. The skinny part on the upper right is where the factory valley port is. I had my bung welded above the much larger part so it is protected from anything but (hopefully) gases getting by.

[supergt99]

My drivers valve cover is blocked off. Pass valve cover goes to catch can, from catch can pcv to intake. Valley cover is going to inlet tube before throttle body.

[Unreal]

Any of the setups that have the valley cover, or any line from crank case to an inlet are still going to pull oil/etc into intake. I don't see the point of that.

[SeaCompiler]

Originally Posted by Unreal

Any of the setups that have the valley cover, or any line from crank case to an inlet are still going to pull oil/etc into intake. I don't see the point of that.

Yes, that is exactly one of the reasons why I am asking, because it seems setups which are going directly to the inlet without going through a catch can are subject to the risk of pulling oil into the intake, intercooler, etc. It seems risky to me.

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I like some of the proposals on the first page and I have decided that if anything goes to the inlet, it will be through a catch can. I understand blocking off with a one-way valve under boost, then normal conditions it pulls. The valley plate port was the real enigma for me and I understand it better now. I appreciate everyone's insight.