I'm installing my Performer X intake on my gsr na built i'm finishing up. And i'm going to need to make a new intake tube. For ease of installation and not having to find the correct fittings. Can i move the valve cover vent line from the stock location of the intake tube to one of the many vacuum sources on my Performer X intake manifold? Does the valve cover need pre throttle body air or does this not matter?

Thanks guys

 

If you are going to keep the cover vent it needs to be pre throttle body

 

I'll set it up with the stock configuration than. Thanks Since i love to learn things what is the reason for the valve cover vent line needing pre throttle air?

 

If you hook it up post throttle body it will be a vacuum leak into the crank case. Just pull one of your vacuum lines off while your car is idling and see what happens it will rev up like your giving it throttle

 

The reason it is pre throttle air is simply because it is not under vacuum and it has been filtered. Technically you can remove that tube and install a filter on the vlave cover, as long as you maintain the stock PCV vacuum hose on the plenum.

 

It lets all the combustion gasses, blowby, and crankcase pressures get recycled back into the engine (and burnt) instead of letting it out to atmosphere and polluting the air.

This is why you see oil residue where the hose goes back into the intake a lot of times. Venting it to atmosphere lets the engine breathe in cleaner air with less oil vapor (which increases chances of knock).

 

The fresh air inlet, that goes between the intake tube (pre throttle) and valve cover, is not a crankcase/engine vent. If you are experiencing oil through the air inlet, you are having PCV system issues or excessive blow by that can not be handled by the PCV system.

A lot of times when you see oil in that tube. It is due to a clogged PCV valve or collapsed hose. These situations cause there to be no vacuum to suck the crankcase gases/oil vapors out of the valve cover/engine. Therefore it exits wherever it can.

 

Oops your right. Was thinking about it backwards. This hose that goes back into the intake (manifold, post throttle body, in line with #2 runner) is where it gets recycled back into the intake.
Been a long time since I had a stock functioning pcv system.