Originally Posted by
2001TEGGSR
Crankcase Ventilation, a direct replacement of the PCV system. The lines usually go to a catch can, which is either vented to the atmosphere or has some form of vacuum.
Exactly. The front of the valve cover is usually vented because it has a baffle right there that will help separate the oil vapors from the oil.
The stock PCV system is inadequate for a boosted application because the PCV valve closes when it sees positive manifold pressure causing pressure to build up in the crankcase because it has nowhere to go. At best, it will cause poor piston ring seal and at worst, it could crack the ring lands.