found this interesting

[htgsr]

Just found this, cant remember what I was looking for but found this quite interesting.
Done a quick search on here an found some stuff but thought I would throw it up anyway as it seems to be something that quite possibly gets over looked when installing a catch can to daily drivers. I know I just had mine going to atmo -soon to be changed
Plus be interesting to get some feedback from peps off here

http://www.dsmtalk.com/forums/showthread.php?t=177223&highlight=catch

 

[Gianni]

Interesting. I wouldn't use a breather off pcv valve anyways. It runs to your intake manifold so will leak preassure. I'd have a closed catch can. The pressure would still suck out of the rocker cover. But collect oil in the can. Fumes would be a different story though. But the valve that runs to the intake pipe (being pre turbo/psi ect can have a breather. That's my thoughts anyways

 

[4piknup]

there is also vacupan. they run the crank gasses into the exhaust. they dont get burnt at all.
http://www.summitracing.com/parts/MIL-85700/

i reckon you still need the pcv running into the inlet manifold, and a sealed catch can, but the other end of the catch can could vent into the exhaust pipe, probably after the cat, and you would need a 3" pipe so you dont have exhaust pressure trying to go into your catchcan. in practice maybe another pcv type of valve could be installed in the vacupan line to stop any exhaust pressure from entering the catch can.
there is a venturi effect as the vacupan enters the exhaust at a angle, this will drop crankcase pressure below 0hg, as long as exhaust is quite large.
we need to realize that in the catchcan setup in the usual way of being vented into the intake pipe before turbo, there is no vacuum source present at that point (or there shouldnt be unless you have a restricting airfilter). it is only the crankcase pressure pushing the vapours out through the catch can and into the intake pipe.

vacupans will be illegal in most cars

 

[htgsr]

Would you not get a venturi effect from the air heading into the turbo an get some suction from that?

Anyone got any good ideas for baffling in the catch can?

 

[4piknup]

dunno about venturi effect, would have to be at a angle on entry. and a venturi is a restriction. most i have seen are at 90* to the airflow

 

[htgsr]

My inlet pipe has a spare nipple on it so ill just use that for now an see how it goes if/when I get it going again

 

[htgsr]

Also yous fallas should check out post 130 on page 9 i cracked up

 

[brisvr4]

I have a -12 fitting into my inlet pipe and it is cut to make the most of the Venturi effect. In fact we tested the intake off the car by just pulling air through and it works a treat.
Also, vac u pan stuff usually doesn't work that well on a turbo system.

 

[Ian91]

Does anyone have a photo of how the catch can should be setup? I can't quite visualize where all the hoses go and come from, thanks

 

[htgsr]

There is a diagram in the thread somewhere if you flick thro it maybe page 8ish

 

[Ian91]

Cheers