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I use one as well. Virtually no restriction when you blow through it. No odor that I can tell but I don't have excessive blowby.
 

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So can you run a closed pcv system with these?
Yes, mine is a closed system. I added a few things to make it work better for a turbo/supercharged setup.

I used a Turbo Coupe PCV valve which has a check that is not supposed to allow boost into the crankcase. In testing it worked properly about 50% of the time. I still used it and ran a 3/8" line off of it to an oil separator like this one: JEGS Performance Products 52205 | Buy JEGS Air Oil Separator at JEGS. From the other side of the separator the line goes to this check valve: McMaster-Carr which is very well built and will not let boost pressure back into the crankcase. From there it splits into two 3/8" lines that run to the intake.

To pull fresh metered air into the crankcase, I used the factory nipple off of the passenger side valve cover and ran a line into the piping after the mass air meter. I installed an inline fuel filter like this one: http://www.autozone.com/filters-and-pcv/fuel-filter/duralast-fuel-filter/246927_0_2606/ just in case to keep anything out of the intake tract. The filter is hidden under the front fender because it would look terrible if not.

This works great for me on a draw thru setup. In boost the McMaster check valve closes off the crankcase from any pressure while the check ball cap releases any blowby. In vacuum, the check ball cap closes and the pcv does it's job like normal.
 

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Discussion Starter #8
Cool. That little checkvalve is just the ticket between the TB and the Valve Cover.

I too bought a Turbocoupe PCV Valve. I hope it works more than half the time.. lol
 

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No, you can't use it to go between the TB and valve cover. The crankcase has to pull air through it and it uses the TB on stock engines because that is metered air. On boosted applications, you can't use the TB anymore because it will be sending boost directly into the crankcase. You can't use the check valve there because under vacuum it has to pull through it. Under boost, the pressure would open it and it would be useless.

I capped off the nipple on the TB. I used the nipple off of the valve cover and ran a hose to the coupling after the MAF. It can draw fresh metered air from there and it will never see pressure from the turbo.

You have two vacuum lines tied together running from your intake to the pcv. This is where that check valve goes, before the vacuum line goes into the air/oil separator. A vacuum line runs from the other side of the separator to the pcv. The check valve makes sure no boost makes it into the crankcase. I don't trust the pcv to work every time.

This is a terrible drawing to illustrate what I am trying to get across. The arrows indicate air flow through the crankcase being pulled by vacuum from the intake.

 

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Discussion Starter #10

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Saw your post @ Bullet.
Lots of good information on that thread by guys that have experience.

2 things to remember in forced induction.
1) motor under vacuum
2) motor under boost

You need to address both. And F no, there is no % of time in the simple 2 equation formula.

1) under vacuum, let the normal course take care of the cleaning. A simple solution is to run 1 line for a PCV system. Just make sure to address the added intake pressure. The addition of a secondary check valve works great.
Photo of an intake I had laying around for example.

EV 127, new screen.



Another showing the addition of a secondary check valve.



Next part to address is what you will do under boost.
You can run a can. But that's a passive system and will only keep your seals from leaking oil. We can do better than that!!

I choose to run a header evac system. I've done electric vacuumes in the past. All I can say is, if there ever was a design that actually worked well. All of us would use them! Unfortunately for a street car, they suck eggs.

With the header evac system, there are few parts to fail.

After several attempts to find a baffle that works, I've settled on the Jeg's brand. It's a nice unit. It has a 3 piece baffling system with a very large suction port. Almost 2" if I remember??

Here is the unit, and the -8 line.



From there I tie the 2 valve covers via a BBRC 'Y' block. -8,-8,-10.
Then a -10 line to a sealed catch can.
With several miles of using this system, there is ZERO signs of oil after the can.
On a monthly basis I have to drain the can.

This is an old picture, but if you look at it, it starts to all make sense.



The picture shows heater hose after the can. You really don't want to use heater hose and instead should use fuel line. Again, it's an old picture and was taken during testing.

Running 2 systems together addresses both Vacuum & Boost. Simply running 1 system will lead to issues.
A PCV system only will lead to blow by issues.
An evac system only, will not adequately clean your oil.
An open breather catch can only, addresses blow by. But doesn't help clean the oil, can cause oil vapor smell, as well as other issues.

A correct PCV & evac system is Active for both scenarios.
A vented catch can is a Passive system.

Good luck!!!
 
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