vortech FAQ: read this before asking vortech questions
#1981
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17 PSI with an SC trim Blower!?!? Didn't think that was possible!
Cool man thanks for the imput! I wouldn't be surprised that once the PCV valve is no longer seeing vacuum, hooking it up as such would pretty much see all the Blow by gas just going out the Driver side vent, but I suppose as long as there's sufficient venting happening, it really doesn't matter, right?
Which leads me to question the point of running both VC's to the catch can. If the bulk of the oil will be drawn from one of them once running no return to IM, then you can simply pop an atmospheric vent on the other side and run a smaller Catch Can, right?
Cool man thanks for the imput! I wouldn't be surprised that once the PCV valve is no longer seeing vacuum, hooking it up as such would pretty much see all the Blow by gas just going out the Driver side vent, but I suppose as long as there's sufficient venting happening, it really doesn't matter, right?
Which leads me to question the point of running both VC's to the catch can. If the bulk of the oil will be drawn from one of them once running no return to IM, then you can simply pop an atmospheric vent on the other side and run a smaller Catch Can, right?
#1982
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17 PSI with an SC trim Blower!?!? Didn't think that was possible!
Cool man thanks for the imput! I wouldn't be surprised that once the PCV valve is no longer seeing vacuum, hooking it up as such would pretty much see all the Blow by gas just going out the Driver side vent, but I suppose as long as there's sufficient venting happening, it really doesn't matter, right?
Which leads me to question the point of running both VC's to the catch can. If the bulk of the oil will be drawn from one of them once running no return to IM, then you can simply pop an atmospheric vent on the other side and run a smaller Catch Can, right?
Cool man thanks for the imput! I wouldn't be surprised that once the PCV valve is no longer seeing vacuum, hooking it up as such would pretty much see all the Blow by gas just going out the Driver side vent, but I suppose as long as there's sufficient venting happening, it really doesn't matter, right?
Which leads me to question the point of running both VC's to the catch can. If the bulk of the oil will be drawn from one of them once running no return to IM, then you can simply pop an atmospheric vent on the other side and run a smaller Catch Can, right?
The reason both are used is cross sectional area. Why run dual exhaust instead of single? More flow. The last thing you want is restriction when venting crankcase gases.
#1984
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Well, when you have built a few cars and tune cars on a regular basis you can use that experience. Until then I would probably listen to all of us on the forums with years of experience and have high hp cars already in the garage.
#1986
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Raj (rcdash) on here I think did some logs and there were a few guys in the large crankcase vent thread by Jet Pilot. Open breather into catch can showed little to no pressure build up in the crankcase from what I remember.
#1987
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Ok, I've read those threads (panned through previously and just re-read again), they mostly mention utilizing a system similar to most, which is similar to the OEM setup I posted in the diagram above.
Granted the concept of venting both of them isn't a bad one, but if you're doing it that way, what's the purpose of having a catch can at all? Why not just install a breather with a filter on bolt VC's and that's it? I fail to see the difference, unless it somehow relieves part of the stink?
It was those threads and some head scracthing that brought this inquiry on for me personally. Hence mentioning Drilling out/modding the stock PCV.
The threads, specifically mentioning JCDASH's setup, and the JETPILOT thread:
http://www.*********.com/forums/119-...case-vent.html
https://my350z.com/forum/forced-induction/403905-crankcase-ventilation-mod-w-pics.html
Which helps me realize that this whole topic would be better suited for that thread, so I'll pop an inquiry/idea there to see if it helps my understanding.
A quote from rcdash that is precisely my feelings on this, and part of why I'd like to see some measure of vacuum in the CrankCase:
Granted the concept of venting both of them isn't a bad one, but if you're doing it that way, what's the purpose of having a catch can at all? Why not just install a breather with a filter on bolt VC's and that's it? I fail to see the difference, unless it somehow relieves part of the stink?
It was those threads and some head scracthing that brought this inquiry on for me personally. Hence mentioning Drilling out/modding the stock PCV.
The threads, specifically mentioning JCDASH's setup, and the JETPILOT thread:
http://www.*********.com/forums/119-...case-vent.html
https://my350z.com/forum/forced-induction/403905-crankcase-ventilation-mod-w-pics.html
Which helps me realize that this whole topic would be better suited for that thread, so I'll pop an inquiry/idea there to see if it helps my understanding.
A quote from rcdash that is precisely my feelings on this, and part of why I'd like to see some measure of vacuum in the CrankCase:
Using 2 breathers right on the valve covers pretty much eliminates any chance of crankcase pressure build up and will work just fine. I like a fresh air pull through set up a bit better since it doesn't smell as much, helps to actively pull fuel vapors out, and helps to maintain vacuum in the crankcase for better ring sealing during idle/cruise (consider the pressure differential between the crankcase and combustion chamber during decel - oil will move in that direction).
I think for any FI setup, drilling out the PCV and opening up the driver's side valve cover orifice a bit is always helpful. My driver's side valve cover hasn't been touched, so that is a point of restriction in my setup which I haven't addressed because the setup is working fine as is. As blow by increases with engine age, I may need to drill that out...
I think for any FI setup, drilling out the PCV and opening up the driver's side valve cover orifice a bit is always helpful. My driver's side valve cover hasn't been touched, so that is a point of restriction in my setup which I haven't addressed because the setup is working fine as is. As blow by increases with engine age, I may need to drill that out...
Last edited by TunerMax; 10-25-2012 at 05:43 PM.
#1988
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Catch can is only used to "catch" oil. That is why a person uses it. With just breathers oil will come out when they vent.
The point of drilling the pcv out is to get a larger hole in order to vent better. The stock opening on that pcv is very tiny and restrictive. Since there is no connection to the manifold anymore there is no reason to have a check valve stopping the boost leak at the manifold.
The pull through is a great idea for idle and cruise so it will eliminate the smell. Since the crankcase will force the gases out under boost it really won't change much under boost. I had mine set up that way with a series of check valves from my catch can to the manifold (some people put it into the intake pre-turbo). It didn't work out so well for me and caused excess pressure in the crankcase and blew my front timing seal out on the highway. After tearing that apart and replacing it I went back to my standard vented catch can and don't have any problems in pressure build up.
To paraphrase in my own words Occam's razor: the simplest hypothesis is the more likely hypothesis.
or the army way : keep it simple stupid
I like simple.
The point of drilling the pcv out is to get a larger hole in order to vent better. The stock opening on that pcv is very tiny and restrictive. Since there is no connection to the manifold anymore there is no reason to have a check valve stopping the boost leak at the manifold.
The pull through is a great idea for idle and cruise so it will eliminate the smell. Since the crankcase will force the gases out under boost it really won't change much under boost. I had mine set up that way with a series of check valves from my catch can to the manifold (some people put it into the intake pre-turbo). It didn't work out so well for me and caused excess pressure in the crankcase and blew my front timing seal out on the highway. After tearing that apart and replacing it I went back to my standard vented catch can and don't have any problems in pressure build up.
To paraphrase in my own words Occam's razor: the simplest hypothesis is the more likely hypothesis.
or the army way : keep it simple stupid
I like simple.
#1989
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in the end you are overanalyzing. I was making 17psi and 460whp on my vortech setup with the stock PCV system and absolutely no issue.
Now I just run breathers on the valve covers. My cams dont pull alot of vacuum anymore so no reason to introduce a potential vacuum leak.
The only reason you would tie vacuum into a catch can setup is to reduce smell at idle. Any other time you are barely pulling an vacuum from a manifold source.
Now I just run breathers on the valve covers. My cams dont pull alot of vacuum anymore so no reason to introduce a potential vacuum leak.
The only reason you would tie vacuum into a catch can setup is to reduce smell at idle. Any other time you are barely pulling an vacuum from a manifold source.
#1990
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Great responses guys, thanks! That pretty much clears it up for me I think. Recirculate if you want to lessen smell at idle/low load, and just vent it if you want simplicity with better ventilation.
I overanalyze because i like (trying) doing it right the first time around, and I also like my mods to perform as a complete upgrade to the stock system, minimal to no shortcomings/sacrifices. It's for that reason I wanted something similar to the OEM setup but with more venting, and an oil catch in line.
I'll probably try running the stock PCV setup with catch can in line for now (standard Catch can install), and see where that goes. I may even pop a MAP sensor in there if I can find one cheap enough to log where things are at, see if I need to do anything at all.
Thanks again for your help and advice on this one!
I overanalyze because i like (trying) doing it right the first time around, and I also like my mods to perform as a complete upgrade to the stock system, minimal to no shortcomings/sacrifices. It's for that reason I wanted something similar to the OEM setup but with more venting, and an oil catch in line.
I'll probably try running the stock PCV setup with catch can in line for now (standard Catch can install), and see where that goes. I may even pop a MAP sensor in there if I can find one cheap enough to log where things are at, see if I need to do anything at all.
Thanks again for your help and advice on this one!
#1991
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GM 3 bar is about 40$. You can get gm 2 bar for around 20$ and someone would probably just give you a gm 1 bar. Go to a pick and pull and swipe one for a couple bucks off a camaro.
#1994
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http://vibrantperformance.com/catalo...1073_1141_1168
Last edited by the3kgt2; 10-29-2012 at 08:29 AM.