What is the best ventilation setup for an SR?

[om3ga]

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?

[Sileighty_85]

You need to have neg crank case pressure, it will help seal the rings as well.

I have mine routed Crankcase>Valve cover T>Oil Catch can>Intake Pipe

there is thread on here dedicated to this topic, if you want more info

[PoorMans180SX]

People who run breathers are stupid.

Sealed catch can systems make more power.

Ones like these:

http://zilvia.net/f/tech-talk/235851...can-setup.html

[Bigsyke]

How does it make more power? Your guaranteed to have unmetered at entering the system at some point if you have any kind of oil leak then your definatey not having more power. The restriction the PCV system makes at any kind of load only makes blowby worse, and once you have a simple leak on a gasket somewhere, your not pulling out any vapors, just cycling air.

My Saab 9-5 v6 has its PCV vented. After a long hard drive you can see the vapors purging at idle. Personally I cant imagine what kind of positive pressure is in the crankcase at WOT with the OE PCV system's small orifices. If you dont drive the car in cold weather I'd vent both ports and make sure you dont keep the pcv check valve use a coupler.

[Wookie384]

Correct me if I am wrong, but the part of the benefit from having the PCV connected the way it is, in OEM form is that there is a vaccum applied to the crank case, it's a fact that the lack of wind resistance will allow the rotating assembly do it job with less resistance, Therefore the motor works easier...

[om3ga]

Originally Posted by Sileighty_85

You need to have neg crank case pressure, it will help seal the rings as well.

I have mine routed Crankcase>Valve cover T>Oil Catch can>Intake Pipe

there is thread on here dedicated to this topic, if you want more info

That is the setup i was planning on doing, i just cannot find space for this can lol. Where is this thread? As long as it isn't this (http://zilvia.net/f/tech-talk/235851...can-setup.html) one because i have read it a few times.

[sidedrifts13]

I run the same set up works great for me

Originally Posted by Sileighty_85

You need to have neg crank case pressure, it will help seal the rings as well.

I have mine routed Crankcase>Valve cover T>Oil Catch can>Intake Pipe

there is thread on here dedicated to this topic, if you want more info

[Sileighty_85]

Originally Posted by om3ga

That is the setup i was planning on doing, i just cannot find space for this can lol. Where is this thread? As long as it isn't this (http://zilvia.net/f/tech-talk/235851...can-setup.html) one because i have read it a few times.

Thats the thread i was talking about

[s14unimog]

same here. I've run the same setup that sileighty described for over 2 years at ~400whp... Not a single drop in my catch can. I've changed the hose since this picture but it clearly shows the routing

[slider2828]

Originally Posted by s14unimog

same here. I've run the same setup that sileighty described for over 2 years at ~400whp... Not a single drop in my catch can. I've changed the hose since this picture but it clearly shows the routing

When you create negative Crank Case pressure, piston rings seal better giving you a tighter combustion chamber..... Nascar runs like -24PSI in their crank case and have a crank case pump belt driven to get that....

Thats exactly what I didn't want... on the track or drifting with altitude changes, that setup sucks.... Been there done that..... Also with high horsepower your turbo is going to draw oil from the crank case during high load g's and it won't get recycled.... Do you run 400 at the track and I am talking circuit not dragging.... but whatever...

The idea of the other thread is to mimic a S14/15/RB26 setup where oil is salvaged....

Hence the other thread that I made about it....

[Giebs]

I'm not too familiar with SRs, but what does the hose that goes to towards the firewall connect to?

[s14unimog]

I run that power for drifting. I've never had the turbo suck up oil as you describe. I've read your thread.

Originally Posted by Giebs

I'm not too familiar with SRs, but what does the hose that goes to towards the firewall connect to?

the top of the block, just below the head.

[slider2828]

Sure no biggy, some people have that problem some people don't... no big deal.... But if you run Laguna or Thill or Infineon.... which has very high vertical elevation changes that setup for sure will have a problem.... Just saying what I have seen.... But hwatever.

[s14unimog]

sure, I can see that. Why not just install baffles in the crank vent line? Similar to the OEM setup but more aesthetically pleasing. Would avoid welding the VC...

[slider2828]

Originally Posted by s14unimog

sure, I can see that. Why not just install baffles in the crank vent line? Similar to the OEM setup but more aesthetically pleasing. Would avoid welding the VC...

Then I am also choking the vacuum that is going to the crankcase to evac the pressure.... Its just getting the most I can out of this system..... if I had baller money I would get a S13/14 hybrid cover.... this is just an alternative....

[s14unimog]

Originally Posted by slider2828

Then I am also choking the vacuum that is going to the crankcase to evac the pressure.... Its just getting the most I can out of this system..... if I had baller money I would get a S13/14 hybrid cover.... this is just an alternative....

well obviously it shouldn't be excessively restrictive, just some labyrinth of passages. But I get what you're saying, all in the same. Scavenging through the exhaust would be good too.

[rc1honda]

Originally Posted by s14unimog

OK stupid question i see from the T to the catch can, But where exatctly does it go from there? Looks like near the turbo but where exactly ? I know i have heard intake but is it?

[PoorMans180SX]

Originally Posted by Bigsyke

How does it make more power? Your guaranteed to have unmetered at entering the system at some point if you have any kind of oil leak then your definatey not having more power. The restriction the PCV system makes at any kind of load only makes blowby worse, and once you have a simple leak on a gasket somewhere, your not pulling out any vapors, just cycling air.

My Saab 9-5 v6 has its PCV vented. After a long hard drive you can see the vapors purging at idle. Personally I cant imagine what kind of positive pressure is in the crankcase at WOT with the OE PCV system's small orifices. If you dont drive the car in cold weather I'd vent both ports and make sure you dont keep the pcv check valve use a coupler.

I hope by now you have done some research and realize how dumb your post is.

rc1honda, it goes to the turbo intake pipe, after the MAF (aka the stock nipple).