Just had a quick scout around but couldn't find anything worth posting, but basically would it be fair to say that if the PCV valve is obviously under positive pressure (boost?) then remapping will increase this pressure and lead to premature failure of the diaphagm?
Would that make sense TT?
Sam
The PCV valve has NOTHING to do with turbo boost! 
It is ONLY the DV which is affected by turbo boost, unless you have modified your engine to work on the two stroke cycle!
The PCV valve may have nothing to do with boost, but it can be affected by it. Therefore increased boost can damage it.
Crankcase Ventilation
The crankcase is maintained in a constant
vacuum while the engine is running.
The crankcase breather that supplies
this vacuum is connected to the intake
manifold.
The crankcase blow-by gases are separated
in two stages. In the first stage, the
primary oil separator in the oil filter module
takes most of the oil out of the gases. A
second separator in the cylinder head cover
removes the remainder of the oil from the
gases.
Since a turbo engine requires a more
sophisticated pressure control system, a
two-stage pressure control valve is located
on the cylinder head cover. If vacuum exists
in the intake manifold, blow-by gases flow
directly into the intake manifold.
If a boost pressure is present in the intake
manifold, a one-way valve in the pressure
control valve housing closes and the blowby
gases flow into the cylinder head cover
ahead of the turbocharger. The system can
detect faulty installation of the pressure
control valve. Unmetered air is detected by
the reaction of the oxygen sensor.
Where - exactly did that blatant cut, copy and paste come from? Because that categorically is NOT from a Volkswagen Group FSI engine? And there are some serious, and fundamental basic errors with that!
And I will categorically state again, boost pressure has absolutely NOTHING to do with the PCV - nothing! Furthermore, it can NOT be affected by boost either.
But hey, you read and stole the above from some other internet forum, so that then means it must be true!
Didnt say it wasnt a copy and paste.
It was copied and pasted from the 'self study guide' for the GTI engine
Have you read it
Plus YOU got that guide from from the SAME internet forum as I did so it must be true.
Page 8 I think you will find.
Still stand by your
Because that categorically is NOT from a Volkswagen Group FSI engine? And there are some serious, and fundamental basic errors with that!
http://www.golfmkv.com/forums/golfgoodies/mk5golfengine.pdf - Self-Study Programme
Yup, I still stand by my claim. Sadly, you seem to be utterly gullible if you honestly think crankcases work on a 'vacuum'. Go and read Hillers. That PDF is simply a 'dummed down' guide for the Yankie audience (whos' intelligence is debatably considerably less than ours).
Here is another mistake from the same said PDF:
High-pressure oil pump drive from a
triple cam on the intake camshaft
I suppose you believe that as 'gospel truth' too!
