intenseapple

I know that this topic has been analyzed and debated excessively here -- I am beating a dead horse. However, after reading thread after thread, it sounds like the ideal properties for a CCV setup on a street car are:

1. Retain normal PCV function to clean crankcase at idle.
2. Increase VTA flow proportionate to engine horsepower increase. 2x stock hp means 2x more VTA flow under boost.
3. Catch can everything to avoid distasteful fume smells

The biggest issue most people run into here is doing both #1 and #2 without drilling another hole in the VC, head, or block. However, I think I have found a halfway decent solution:


The exhaust side of this setup works. This has been generally agreed upon. If you don't want to suck fumes into your intake tract, you could vent CC1 to atmosphere, does not affect function of the system.
A quick description of states and their relation to the intake side of the system:

1. Engine at idle: PCV valve is open slightly, CV is closed from IM vacuum, thus vacuum from the IM is applied to the VC/CC
2. Engine under load <=100 KPa AKA not in boost: PCV valve is fully open, CV could be opened or closed but likely closed, PCV still applying vacuum to VC/CC
3. Engine under load > 100 KPa AKA in boost: PCV valve closes. A second check valve could be added inline with the PCV to ensure no leaks. CV is opened, especially with excessive blowby and/or low pressure on the pre-turbo intake side if routed there and not VTA. VC/CC are vented passively (if both CV and CC1 are VTA) or with slight vacuum from the intake tract if plumbed there.

This checks off all of the goals I mentioned above and, while fairly complicated, doesn't really have any downsides as far as I can tell. Anyone have other thoughts?

LeoNA

When I tried a similar setup cc1 never caught anything.

intenseapple

Any idea why? We’re you using a slashcut in the pre turbo intake piping?

LeoNA

Yes. I also enlarged the hole in the vc between the side to center areas.

95RedM

My idea was similar to this. I drilled a hole in the top of my valve cover and routed both sides of the VC to a single vented catch can, and put a strong check/PCV valve in the factory location that is capable of holding 35psi without leaking. So that I can have the ventilation of 5/8” hoses in boost with the evacuation at idle and vacuum of the stock setup (street car). This works well. Your system may work better because it eliminates oil from getting into the IM or pre-turbo. Anytime I tried to put a hose from th VC to pre-turbo, even with a catch can, it filled my charge pipes with oil. Horrible. So I don’t plumb pre/turbo. Idk if the VVT has anything to do with that but I found it rather odd