2k13jk: Review the design of the PCV system with the Prodigy kit as I've described (admittedly, scattered across a couple posts)...

Keep in mind that there's two importantly distinct sides of the PCV system:
1) PCV hose, running from the PCV valve to the intake manifold.
2) Breather, or make-up air hose, from an open valve cover vent (no check valve of any type) to the intake system, somewhere up-stream from the throttle body (not a vacuum source), but down-stream from the air filter (source of fresh filtered air).

There already is a check valve in the PCV hose with the Prodigy kit: http://jeeplab.com/showthread.php?13...ull=1#post2116

So there is no boost directly entering the crankcase.

Normal operation for the PCV system is that manifold vacuum sucks air out of the crankcase through the PCV hose. The breather hose allows fresh, filtered air to enter the crankcase, replacing the oily air that was sucked out.

But when on boost, cylinder pressures are much higher than a non-boosted engine, which creates quite a bit more piston blow-by than a non-boosted engine. This causes a reverse airflow from the crankcase through the breather, because that's the only exit path available (The check valve in the PCV hose is held closed by manifold boost pressure). This happens with all the boosted systems.

With the supercharger setups, the breather hose is connected back up to the intake system (like the stock setup). This is why you get oil in the intercooler and supercharger. And this is why adding a catch can to this hose can improve on-boost performance, and even allow for a "hotter" tune.

With the Prodigy kit, the breather hose has its own air filter and is NOT connected back up to the intake system. The Prodigy kit does not suffer from the consequences of oily crankcase air when on boost. I fully described this in my recent post about my PCV setup, including reasons that it's not ideal, and that I'd really prefer to eventually run it through a catch can and back into the intake.

Adding a catch can to the PCV hose has less of an impact on a boosted engine, because oily air only comes through that hose when there is vacuum in the manifold (partial throttle, light load, not when trying to make big power). A catch can here does not prevent oil from coating the inside of the intercooler, because this hose is a direct line from the crankcase to the intake manifold, skipping past the whole intake system.