- Thu Apr 03, 2008 10:22 pm
#49079
teal_dx wrote:I assume the black arrow is an inline check valve
what is the little grey thing on the runner of the intake manifold?
this is gonna have to go in the DIY section soon 
The black arrow is labeled "brake booster check valve". You go to the junkyard and pull it out of the brake booster vacuum line. It's far superior to a PCV.
The little grey thing on the intake manifold was the PCV valve as in the original diagram which I left there just to show that it will no longer be used.
Your current setup is a breather. I forget what the derogatory term for that was. I wouldn't even pull out of the driveway with that.
The exhaust slash cut gives you more vacuum. But you don't want TOO MUCH vacuum or else you'll suck oil out of the valve cover. The problem with exhaust is that it's hot. You're going to have a rubber hose attached to it and that will cause problems. It's not impossible to do but it's difficult.
The pre-turbo slash cut is easier and it provides sufficient vacuum. Used in conjunction with the intake manifold vacuum, you'll have vacuum under all conditions. But the brake check valve is critical to prevent boost from flowing into your crankcase from the intake manifold.
There is a great article on this somewhere out in the net, but I am clueless as to where. Someone tried different methods, measured the vacuum with a gauge under all conditions, and had the research to know how much vacuum is optimal. I forget the details but remember the conclusions.