Well, I'm just gathering parts/information right now for a soon to be s475 turbo'd 5.3. From what I've read on here, I need to put a breather on both valve covers, plug the hose to the throttle body and that's it right? I think the only purpose of a catch can is to contain the oil smell if there is any? I'm running a speed density tune by the way. Also, do I need to run check valves on anything to prevent boosting something like the brake booster or evap line coming from the manifold? Any information/comments will be appreciated!

 

One or two breathers will work. I opted to keep the factory PCV system (with a check valve and catch can inline) because the fumes were too much in traffic. And the PCV system is supposed to help with oil life and cleanliness inside the engine. If you change your oil more often then its less of an issue. And then I ran the passenger side valve cover nipple to the turbo inlet with a 3/8" line. I thought it would be too small but I have yet to see evidence of pressurizing the crank case. The vacuum in the turbo inlet also helps to pull fumes from the motor in boost. No signs of oil in the inlet either after ~1k miles. Nothing else needs a check valve.

 

So the drivers side valve cover goes to the catch can? sorry, little new to this. Is the catch can then run to the turbo inlet or just vented to atmosphere?

 

To just get up and running, I put a check valve near the manifold in the stock PCV line from valve cover to intake on the drivers side and capped the fresh air inlets on the passenger side valve cover and TB... ran a oil breather cap from advance auto, which surprising fits snug into the oil cap tube. so itll vent there in boost atleast. I plan on getting a setup like Ferocity02 has soon, though with a catch can, and it under vacuum during boost.

 

Here's a diagram of mine and how the air flows in boost and vacuum. The only thing I'm going to change is putting a large fitting into the top of the oil cap and run a 1/2 or 5/8 line to the turbo inlet to ensure the blowby can escape easily in boost, and then cap the nipple on the passenger side valve cover. From what I've seen a catch can is not necessary in this line, I haven't seen the slightest evidence of oil getting into the turbo inlet yet.

If you're running MAFless then the options are endless. If you use a MAF then it gets much more difficult as you cannot use the PCV system and a breather because it would just be a glorified vacuum leak. My tuner said it would be to unpredictable to tune around it, but perhaps it can be done. The only option to use just breathers and no PCV, unless you want to get fancy with diverter valves or something.

 

Well that helps me alot, shows me exactly how it works.

 

I am running a breather on the pass side, blocked the TB hole off, the driver side remains un touched. No catch cans. Never had any issues with oil puking out of the engine.

 

That works too, except sometimes the PCV valve can leak in reverse flow, not a huge deal. I'd check it though.

 

???..

 

I am running mine exactly like this Minus the catch can and it seems to be working fine.
I have a MAF tho and it doesnt seem to bother it.
As a added bonus I used my throttle body port on the Passenger side as a Reference for the Wastegate since its before the throttle body.