I know the catch can install questions have been covered in this forum before, mostly with FD's, but I am curious to know why not keep the PCV valve and could it OR should it be "T" split from both filler neck and centre iron to catch can ???

I have a HBP S4 T2 with greddy catch can and am recirculating both oil and gas vapours back into intake.

Previously, when I would cap/block 1 vent tube of either the filler neck or centre iron, my filler neck and dipstick would pop off and spit oil in engine bay at 7000rpm on dyno.

I then installed a breather filter on oil filler tube and no more oil spills in engine bay, YAY!

Howerver, I am wondering if installing a new oem PCV valve would help make my car smoke less on idle and while driving or no difference at all ?

My setup right now looks like this... Ignore the filter breather, I would pass a hose to the centre iron if necessary.

 

some advice or opinions plz

 

Looks like you are missing a vacuum connection to the OEM purge valve. That would be the vacuum connection which opens the valve.

Here's how I configure these.

Bottom nipple on middle iron to catch can.

Upper nipple to vacuum port on intake manifold through a 1 way check valve (flowing to intake) for big port/big boost or a generic parts store PCV for more stock engines.

If stock ECU, the filter connection on the top of the catch can needs to connect to the intake tube just after the AFM.

If standalone, you can just stick a filter on it.

 

Where is the purge valve normally located, is that on the emissions rack?

I have to see what I need to do since I'm removing all emissions and both charcoal canisters.

Rotary > Pistons

 

Probably should do one or the other fully, don't mix the systems.

I put all the stock PCV/charcoal systems back into my car and it's perfectly happy with my standalone and upgraded turbo engine. I did this to keep the smelliness down in my engine bay.

Of course some people don't care and just plug the lines and put a catch can.