VC Breather

[TSITurbo95]

So there are two breathers on my vc, one going to the intake pipe, and other going what looks like the intake mani. To install a catch can, do I unhook the one going to the intake mani too and just plug it off, and rout both breathers into the catch can?

 

[snakeyes711]

Just leave that one alone, and run your catch can. Its probably your PCV valve.

 

[warranty]

The one going from your VC to the intake hose is the breather hose. You can either just directly vent it with a breather filter (and plug up the intake side), or splice in a non-vented catch can. If you install a vented catch can in between the VC and the intake hose your engine will suck in unmetered air (which causes some drivability problems).

The one going from the VC to the intake manifold is the PCV hose. The PCV valve is screwed into your VC. You can splice in a non-vented catch can into that hose to catch the oil, but if you want to vent THAT then you'll need to replace the PCV valve with something that is free-flowing, and plug up the intake manifold side of course.

 

[quiksilver20004]

do NOT eliminate your PCV valve and try to run the catch can between the VC breather and tie it back into your intake tract, before the turbo. This VC venting system is there for a reason and you need to maintain it! When your car is running under vac the PCV valve is open and is pulling air throught your valvecover and removing all the airborn crap in your motor and when you hit boost the PCV valve shuts and the intake creates a suction on the VC and pulls all the blowby gasses out of your VC and helps maintain oil life and integrity.

 

[snakeyes711]

sounds convincing enough for me!

 

[joegamma1]

do NOT eliminate your PCV valve and try to run the catch can between the VC breather and tie it back into your intake tract, before the turbo. This VC venting system is there for a reason and you need to maintain it! When your car is running under vac the PCV valve is open and is pulling air throught your valvecover and removing all the airborn crap in your motor and when you hit boost the PCV valve shuts and the intake creates a suction on the VC and pulls all the blowby gasses out of your VC and helps maintain oil life and integrity.

+1
Now theres some common sense, the breather is exactly that; it breathes both ways, and designed to do so.
Both to keep your engines oil clean and the air outside the car, recirculating it back into the intake.
The problem(and reason we use catch-cans) is that oil gets sent into the intake, PRE-turbo, which gums up the turbo,ic piping, ic, the throttle body AND the intake manifold.
SO:
Put it between the VC breather and the intake tube, NOT the PCV line, if you want to do something with the PCV, put a check valve in it so you can actually trust the function of the PCV valve is being carried out.
Good luck