I just for the life of me get my head round the catch can

[Nino]

I need to get this nailed and rio, ive seen what rocker has hopefully he will reply soon

[rockmonkey69]

No, the T pieces goes between the rocker cover and top inlet of the catch can and goes down to the block opposed to the hockey puck.

The lower catch can inlet goes directly to the hockey puck.

Excuse the poor edit of your pic, but you'll get the idea:

As above, that is indeed the correct route.
The elbow for the crankcase breather from the block can be replaced with a billet adapter, a few companies sell these now, I purchased mine from integrated engineering
http://www.performancebyie.com/integrated-engineering-billet-block-breather-adapter-for-1-8t-mk4-2-0l



And of course I just used my valve cover as a t-piece

[Nino]

Very interesting, your link only shows the red part?

[rockmonkey69]

All the other hoses, fittings and adapters were purchased separately from other vendors. Depending what route you plan to plumb the crankcase breather you will need different angle fittings. They are easy to source, it is only the block crankcase breather adapter (red part) that is unique to a few vendors that's why I thought to include the link for that.

[Nino]

Arhh okie dokie cheers for that

[Dalo Harkin]

forgive me jumping in, but what difference does it make what goes where in the catch can, don't all the gases end up in the catch can anyway 

[rockmonkey69]

A well routed system will better evacuate crankcase gasses and prevent an excessive build up which normally leads to the oil dipstick popping up and oil forcing it's way through the oil filler cap. So it should be fine as long as this doesn't happen.

While moving the t-piece on a system ventilated to atmosphere is fine, doing so on the above with a catch tank fitted will effectively mean gasses from the rocker cover breather will bypass the catch tank.

[Dalo Harkin]

so am I right in thinking it doesn't matter which line the T piece is in, was what I was getting at.. I don't want to chop all mine up again to route a different way unless its essential.

I don't have the hockey puck in mine as it was broke so its just a 90 degree piece of plastic now into the TIP, that routes to the T piece where one side goes to the catch can and the other to the oil breather part and then I just have the crankcase directly to the other catch can inlet

[rio_gti]

both the breathers need to enter the can first... or there would be no point in having the can there 

[dom]

so am I right in thinking it doesn't matter which line the T piece is in, was what I was getting at.. I don't want to chop all mine up again to route a different way unless its essential.

I don't have the hockey puck in mine as it was broke so its just a 90 degree piece of plastic now into the TIP, that routes to the T piece where one side goes to the catch can and the other to the oil breather part and then I just have the crankcase directly to the other catch can inlet

As Rio says, you need a single line going from the catch can to the TIP.

The whole idea is that the breathers both filter through the catch can to catch all of the 'gunk' to prevent it from entering the TIP.