i cant see any filter or moving parts? mabye a restrictor? whats with that spring in there?

crank case. That is one of the reasons I am putting a catch can on my car.

Positive Crankcase Ventilation.

Basically, it helps to stop the crankcase from being pressurized. Plus, if any exhaust or whatever gets past the rings, it can vent through there, helping to prevent oil contamination.

I just disconnected mine (pulled the motor out tonight), and oil came pouring out.

Is there no way to stop it short of going back to stock?

the larger turbo flows more air, so it sucks more air in, and draws oil in from the crankcase. This oil then goes through the turbo and into the combustion chamber where it gets burned. Which is bad, since oil can cause detonation.

You should probably check your oil feed line and the oil return line. Those are the only two oil related things that should have been changed during the upgrade.

The oil ends up all over my rear bumper. I am putting on a catch can soon.

It's actually not a valve at all, dunno why there's a spring in it. The real PCV valve is actually on the left side of the engine under the intake manifold.

Under boost conditions, the main PCV valve is closed, so this would be the only way to vent any boost that may have built up in the crankcase.

Plus it could help releive a vacuum condition in front of the turbo.

and the car keeps sucking down oil every day.

When I get done putting in a new line for the catch can and take out the valve I will crack it open since it does not do much anymore.