You can get the brake booster check valves from the HELP section at your favorite parts store. I bought the oil separators from Home Depot (they're the same ones that Steeda sells for like $40. Home Depot sells them for $7 a piece). The hardest part is getting the check valves plumbed up because of the size of the intake side. It's just a matter of finding yourself a set of fittings etc. to adapt it down. I'll take some pics today and post what I've got for you so that you have a better idea.
Here, I'm going from the PCV port at the rear of the intake to the intake manifold. The brake booster check valve is the piece at the top, above the hose clamp. Everything else (other than the oil separator) is just hose fittings etc. to adapt the various ports. It all tucks down nicely into a small cradle that I made, that is attached to the rear of the shock tower.
The reason that I did this is because the PCV valve was doing a poor job of keeping the oil from working it's way back into the intake from the PCV port. The extra check valve cured this. With this setup, air/oil can only travel one way... through the separator and TOWARD the intake valve. I don't have to worry about boost pressure pushing it the other way.
This one is simple... it requires no check valve since it only pulls at idle and part power anyway.
The portion that I haven't done yet is to put another check valve and separator into the passenger side valve cover. I have the parts and will do it the next time I have occasion to pull the blower. That will plumb into the PCV port as well.
Thats just what I needed to see man. My brother has those on his supercharged Harley truck. But I didnt really understand what they were for... going to get the stuff right now!
In that first pic, where is the other end going to? I know one end goes to the PVC on the back of the intake, but where does the one on the left side go if your looking a that pic?
The top picture shows the line I have going from the PCV to the intake.
The bottom picture shows the one I have going from the oil filler neck to the intake.
Because you're using a centrifugal blower and your throttle body will see boosted air, you should install a check valve inline with the separator to your oil filler neck. It will keep you from pressurizing that valve cover with boosted air.
With my setup, the intake NEVER sees boosted air. Only the pressurized manifold AFTER the blower sees boost.
I tried the breather method before and it probably wouldn't have been an issue if I were running a centrifugal. What I noticed with the breather setup on my combo was what I call, "chop" during low speed driving. It was a pretty aggrevating to me and acted like a vac leak.
I switched back to the closed system and it smoothed out considerably. All that remains is for me to put one more separator in-line to the intake from the pass valve cover and I think I'll be good to go.
I'll tell ya though... I think that just having the little bit of extra plumbing in there has made as much of a difference as having the separator(s). I say that because I used to see more oil sitting in my intake than I do in the separators. A portion of that may be due to opeing up the plumbing and providing more than once source than just the PCV port to pull from. Sharing that volume between mutiple ports has to have slowed the air velocity going through the PCV (causing it to pull less oil mist through the PCV).