Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum - View Single Post - What is the best ventilation setup for an SR?

om3ga · 10-25-2010, 04:09 PM

I see a ton of mixed results on this topic, i would like to put the best options in one place for a proper ventilation setup on a turbo SR.

I see a ton of people running breathers on the front of the T on the valve cover like so.

I also see crazy setups with the PCV valve hose running to a can along with a hose from the ventilation T running to the can and then the can having a breather on it.

Like this

I have always heard that it is best to have a vacuum source from the valve cover such as the stock setup for example that runs a line from the valve cover to the intake tube for vacuum.

From my understanding the PCV valve at idle is open which is pulling vapors out of the engine at idle then while boosting or driving the PCV valve is closed and that is where the vacuum from the intake tube would come into play and suck vapors/pressure out of the engine.

So do neither of these matter and you can just basically leave them venting to atmostphere like a lot of setups with a single catch can or does it actually cause problems?

Who knows? What is the best setup for crank case ventilation. Can you have the valve cover just vented to atmosphere and be fine with it?

10-25-2010, 04:09 PM	#1
om3ga Zilvia Addict Join Date: Jan 2007 Location: Up and Down! California Posts: 878 Trader Rating: (8)	What is the best ventilation setup for an SR? I see a ton of mixed results on this topic, i would like to put the best options in one place for a proper ventilation setup on a turbo SR. I see a ton of people running breathers on the front of the T on the valve cover like so. I also see crazy setups with the PCV valve hose running to a can along with a hose from the ventilation T running to the can and then the can having a breather on it. Like this I have always heard that it is best to have a vacuum source from the valve cover such as the stock setup for example that runs a line from the valve cover to the intake tube for vacuum. From my understanding the PCV valve at idle is open which is pulling vapors out of the engine at idle then while boosting or driving the PCV valve is closed and that is where the vacuum from the intake tube would come into play and suck vapors/pressure out of the engine. So do neither of these matter and you can just basically leave them venting to atmostphere like a lot of setups with a single catch can or does it actually cause problems? Who knows? What is the best setup for crank case ventilation. Can you have the valve cover just vented to atmosphere and be fine with it?