The stock setup works just fine, if you are stock (if you ignore the fact that the stock pcv doesnt keep oil from being sucked into the intake manifold).

When the pcv valve closes on a stock car, what you are calling the inlet is actually an outlet. The vacuum generated in the intake tube pulls those crankcase gases out of the valve cover and into the intake. There is no fresh air being drawn in during this time. Fresh air being drawn in during idle is a side effect of how the system is plumbed, not the goal.

It is not a one way system. At idle and decel, fresh air is drawn in, but as soon as the pcv valve closes (accel), crankcase pressure and blow-by is pulled into the intake via your "inlet". In this way, crankcase pressure is being relieved at all times on a stock car.



This is the turbo forum though. The stock pcv doesnt work under boost. The stock pcv works during periods of vacuum: idle and decel.

What happens when your not in high vacuum? Crankcase pressure is still generated, and that pressure is going to build until it finds a release. Sometimes its through the dipstick tube. Sometimes its through your main seals.

The goal then is to reroute the pcv to avoid boosting the crankcase, but still having a means of pulling blow-by and crankcase pressure at all times, both idle and under accel. One method is to reroute the "inlet" port preturbo -- depending on the setup though, very little to no vacuum is actually generated though. If you run an open turbo, or just a filter on the turbo, this is essentially no better than just venting that port to the atmosphere.

Another method is to run a vacuum pump. This is costly and unless you run a 350 in your eclipse, your probably not going to find a bolt-on kit. Some people use electric smog pumps, but they dont usually live long when run constantly.

Another method is the exhaust evac setup. Im choosing this because its the only means other than a vacuum pump that completely isolates the intake tract from oil and contamination and still generates vacuum in the crankcase. I will be running sealed catchs inline to avoid just dumping blow-by in the exhuast as well.

95 Avenger
ATX->MTX Swap
Holset HX40 @ 26 psi