PCV Help?

You only need one check valve. The PCV line should go from the PCV to catch can to check valve to intake vacuum source. The turbo inlet will not have enough vacuum at low rpm. You can have a line from the valve cover to the turbo inlet similar to the stock set up to help with crank case evacuation under boost. A oil separator could be in that line too. There are many theories on this. On the Corvette Forum, there is a member Kingtal0n that has a many posts on how the PCV system works and what the vacuum a needs are for the PCV and before turbo inlet for engine evac under pressure.
Another theory on oil in the PCV line I've heard is oil from the turbo return line getting on top of the intake bathtub gasket and running to the back of the engine is getting sucked up in the PCV valve. Don't know if that one is possible or not.
Great response, I will run the 1 check valve after catch can. I do have breathers on both valve covers. I hear that should help? I’ll update soon as I’m done today or tomorrow? Thanks, Gene
Vents in the valve covers work fine if they are free flowing. I had got a new set and the rubber flaps were almost closed. It ended up not being enough flow to let the internal pressures out. That ended up pushing the dipstick out. I just cut the flaps out and all was well.
I’m in the process of making CAI but, I finished the PCV, here’s a few pics, basically working forward…new pcv- rubber hose to inlet of catch can - rubber hose on outlet going to check valve - another rubber line going to intake tube. I didn’t have a 3/8 90 free elbow but I did have a straight hose barb and a old O2 Fowler I welded into tube and straight barb screws into it. Gonna try this setup and see what happens? Idk…forgot to mention, removed charcoal canister? Might relocate it? For now, plugged metal line from vacuum block under TB and put a one way check valve on the vent line. I might put a gas filter in it? From what I read, seems to be the thing to do?
You want to use the 3/8" inlet on top of the throttle body. Put the check valve in the line between the catch can and the vacuum port. The line going to the intake is not needed. If you still want to use it, you'll need a sealed valve cover cap with a 3/8" port in it. Run that without a check valve to the intake port. You can run an open cap on the other passenger side.