Yes, but you also dont want too much vacuum(negative pressure) being applied to suck presssure out because this can increase blow by of the rings. This is why the pancake valve is designed to control how much vacuum there is at turbo hose vs how much pressure is inside the crank case.

No matter how much you try, when running a vacuum source some of the oil or oil vapor will find its way to the vacuum source. This is why race cars tend to use a vented can that has a large enough outlet(filters) so that there isn't all that much pressure in the can.

 

the pic is attached as a thumbnail in my last post, I shouldve been more specific.

When I said that I want it to work under boost and vacuum, I meant that I want the can to collect oil vapor when the intake is charged and when it is under vacuum. Each condition results in different flows and the cathc can may be positioned to be effective for only one of them.

The setup that I am thinking about will probably only work under boost, not sure. I basically want to stick a closed can in the hard pipe (breather line) that goes from the pcv to pancake valve on the TIP. I pretty sure that this is a sensible setup, but I want to be 99% sure before I begin modifying things. I also dont know how to disconnect the one end of the breather line.

 

Basically what you are discribing is just putting an inline catch can into the stock hard pipe. The stock setup works off of vacumm all the time since it is connected to the turbo inlet pipe in front of the turbo and the turbo is always spinning once the car is running, which means there is vacuum 100% of the time.

Plenty of people have done it just that way. There are 2 ways to do it. Remove the rubber hose at the end of the hard pipe and replace it with a longer hose to the catch can, then another line from the catch can to the pancake valve. The other way is to cut the hard pipe, have someone weld both ends closed, weld them back together and weld 2 fittings into each pipe. Then run lines to each of the fittings to a catch can. Doing it this way allows you to hide the catch can and the fittings behind the engine.

There is a thread on this forum about this from Fred.

 

Ghost posted the link to Fred's DIY on Audizine. I am thinking about doing something that is nearly identical, minus the braze welded brass fittings. I am curious about how it all worked out for him?

 

Not sure since he no longer posts and really hasn't driven his car all that much lately since it is not registered.

 

One more question before I proceed with installation. The inlets to my catch can are ~3/8''. Should I run large tubing, ~1'', from the hardline all the way to the can to minimize flow restrictions created from the smaller lines, or is it not that important?