[chrisp]

Originally Posted by JLMounce

That's correct, it's functioning like a PCV valve where you're moving pressure from the crank case to the intake, until there is a surplus of pressure and at that point the draft can will vent the pressure.

The breather has some foam in it to keep oil contained, but is otherwise open.

I did not have to change anything in my tune when I made this change and have not witnessed any changes in my reported AFR's or my short/long term learn trims.

The big thing this is doing for me is providing ventilation operation during high vacuum/high rpm situations where a stock type PCV valve would otherwise be closed.

Any increase in engine vacuum @ idle after the upgrade ?