would a FIT benefit on a catch can?
You can do it, I personally wouldn't. But some would call me eccentric.. or OCD
It should.. but how much air is actually bypassing the system is what will determine that.
I have seen people run their blow off valve to atmosphere because they like the sound (and maybe it gives them ricer street cred?) on cars where the MAF is pre-turbo so the majority will stall between shifts and at stop lights with a generally crappy idle.. but sometimes people can get away with it.
There is practice, and then there is theory. So, it is tough to say. As a general rule I would suggest not to do it.
So I guess try it? If you can get away with it go for it. But I am not sure what the benefit would be, aside from maybe cost advantage?
Depends on the car, and that cars configuration.
On our cars GE/GD, I would segregate them and plumb everything back into the system. YMMV
I have seen people run their blow off valve to atmosphere because they like the sound (and maybe it gives them ricer street cred?) on cars where the MAF is pre-turbo so the majority will stall between shifts and at stop lights with a generally crappy idle.. but sometimes people can get away with it.
There is practice, and then there is theory. So, it is tough to say. As a general rule I would suggest not to do it.
So I guess try it? If you can get away with it go for it. But I am not sure what the benefit would be, aside from maybe cost advantage?
Depends on the car, and that cars configuration.
On our cars GE/GD, I would segregate them and plumb everything back into the system. YMMV
Please share pics of your catch can! A whole pint of oil is a lot.. you might need bigger lines or a bigger check valve... Did you have fittings welded to your valve cover or are you using the stock fittings?
Have you ever hot tanked your IC to clean all the gunk out?
You mentioned that you are venting your can to atmosphere.. Is there at least a filter of some form?
Otherwise you will pull whatever is blowing around under the hood into the engine under vacuum.. dust, leaves, etc.
But based on your build and all of your posts that I have come across, I would imagine you are already aware of this...
If so please disregard this last portion of my post. I am genuinely curious about the first couple questions either way
Have you ever hot tanked your IC to clean all the gunk out?
You mentioned that you are venting your can to atmosphere.. Is there at least a filter of some form?
Otherwise you will pull whatever is blowing around under the hood into the engine under vacuum.. dust, leaves, etc.
But based on your build and all of your posts that I have come across, I would imagine you are already aware of this...
If so please disregard this last portion of my post. I am genuinely curious about the first couple questions either way
Current setup
Now it's basically the same type of catch cans, ones a knock off since it's considerably cheaper that does the same thing and looks the same. The old setup would throw oil back into the system. I was talking about all that oil after a good half a year of driving. Never seeing the catch can fill up but just to flow back into the intake. I've never cleaned the Intercooler, never thought of hot tanking it. I'd assume I'm losing some power there. Anyways, the new setup is an open end with a filter. This can fills up and needs to empty periodically or else the engine will run choppy.
That is just beautiful.. Well done sir.
Are those -6AN fittings I see??
You stand to pick up a good deal of power if you were dumping that much oil over a year by just cleaning the core.
That choppy running is most likely oil vapor and blow by gasses inducing knock retard.
A clean core and a clean catch can should net you some power back!
Both those intake plenums and the lower intake manifold in the second pic are just top notch!
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Joined: Oct 2007
Posts: 2,304
From: Illinois
@BC: if I'm not mistaken... that type of catch can does not have any mesh on the inside. The mesh catches the oil when blown into the catch can.
Last edited by ThEvil0nE; Jan 21, 2011 at 11:43 PM.
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Joined: Oct 2007
Posts: 2,304
From: Illinois
I guess you can modify it and use a screen on the enterance side so that water doesn't form, but the fumes would follow it to the bottom and gather with out it, because oil is heavier.
Not true, Oil can come in and out and only catch some of the oil or not at all. It really depends on how much pressure there is. Like my old setup, my catch can never filled at all. It stayed only a few drops full. A baffle is needed (mesh) to help catch the oil and bring it downward.
I agree. The amount of pressure used to dump the oil into a rather small catch can will definitely need baffling (don't know if that's a correct word lol). Without it, most of the oil sprayed will be sucked right out into the intake.
Last edited by ThEvil0nE; Jan 22, 2011 at 12:11 AM.
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Joined: Oct 2007
Posts: 2,304
From: Illinois
Not true, Oil can come in and out and only catch some of the oil or not at all. It really depends on how much pressure there is. Like my old setup, my catch can never filled at all. It stayed only a few drops full. A baffle is needed (mesh) to help catch the oil and bring it downward.
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Joined: Oct 2007
Posts: 2,304
From: Illinois
Sorry about jumping in, The catch can is suppose to be put away from the motor were it cools the gases and drops in the can. Honda vtecs are notorious for oil getting past the the valve seals because of high oil pressure needed to operate the vtec. Usually the valves need to be adjusted if its to bad. Happen on every Honda I seen with a oil burning problem and that was the problem.
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Joined: Apr 2008
Posts: 364
From: oregon
our cars are slow, but the funnest time anybody has ever had while playing gran turismo, is when they first start out with that terribly slow car, and slowly increase it's speed. when you get the fast cars it's not THAT much fun. ok it's a little fun...
but the fact remains, most sport compacts can easily out corner most supercars with the same amount of money put into them as a supercar, i watched the some SCCA stuff today on speed channel, and much to my surprise, i saw a team of kia forte's LAPPING a mustang. slow cars FTW
Last edited by wontfit; Feb 5, 2011 at 08:48 PM.
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Joined: Feb 2011
Posts: 97
From: Southwest US
Does anyone have a link to a diagram or image showing the proper way to connect a catch can on a naturally aspirated GE motor (2009 - 2011)? I have a brand new Greddy polished 15mm tank I never opened, from my old turbo car. I can get some 9mm fittings to screw onto it with new hose.
I'm just not quite clear on how to connect this properly. Thanks gents!
I'm just not quite clear on how to connect this properly. Thanks gents!
Last edited by XJP5; Mar 19, 2011 at 01:37 AM.
Somewhere around here I have an old hookah made from a dark blue bottle... If I can locate it I will have a very trick catch can (oil vapor separator).. I got that thing 41 years ago at the first head shop in Dallas...
I love how this thread has flowed and provided so much useful information... The thing about oil flowing into the intercooler on BlueCell's work of art has opened my eyes to one of the reasons why my intake air temps are as high as they are... I can see that I am going to have to do better than a Mason Jar or old hookah as a means of dealing with the amount of blow by I have when on boost on a hot Texas day.
You don't have to be fast to have a catch can.. 
You realize that oil vapors and other combustion blow-by gasses get sucked into the intake under vacuum and make you far more knock-prone? It also helps cut down on carbon and other forms of grime that build up in the intake tract and cylinder head?
Also meant to point out in my initial response that EVERY piston engine has blow by, just to what extent is the question. Thats why we all have PCV's...
You realize that oil vapors and other combustion blow-by gasses get sucked into the intake under vacuum and make you far more knock-prone? It also helps cut down on carbon and other forms of grime that build up in the intake tract and cylinder head?Also meant to point out in my initial response that EVERY piston engine has blow by, just to what extent is the question. Thats why we all have PCV's...
Agree.
To understand its purpose you have to understand blowby. Blowby exists in all cars as leftover combustion gasses that leak past your piston rings back into your crankcase. Pistons dont seal 100% thus some of this gas will escape. This causes pressure in your crankcase which is recirculated because of emissions regulations back into your intake system. This is especially a problem in turbocharged cars and constant high reving cars due to the excessive cylinder pressures. A catch can removes the oil and other contaminants and prevents them from recirculating. Blowby is recirculated for emissions reasons, but it can cause quite a few problems. Oil gums up intakes and intercoolers, making them less effective. Blowby that is mingling with your air/fuel mixture can lower its effective octane, not only lowering power potential but also encouraging detonation. Lets just say you want to eliminate as much of this as possible.
The reasons why I just installed a catch can is do to the fact that I track my fit constantly and canyon run. My fit runs constantly at high revs during long sessions. I have found about 3 table spoons of oil coming from the pcv line in my PRM instake every time I cleaned it at about 5k miles.
To understand its purpose you have to understand blowby. Blowby exists in all cars as leftover combustion gasses that leak past your piston rings back into your crankcase. Pistons dont seal 100% thus some of this gas will escape. This causes pressure in your crankcase which is recirculated because of emissions regulations back into your intake system. This is especially a problem in turbocharged cars and constant high reving cars due to the excessive cylinder pressures. A catch can removes the oil and other contaminants and prevents them from recirculating. Blowby is recirculated for emissions reasons, but it can cause quite a few problems. Oil gums up intakes and intercoolers, making them less effective. Blowby that is mingling with your air/fuel mixture can lower its effective octane, not only lowering power potential but also encouraging detonation. Lets just say you want to eliminate as much of this as possible.
The reasons why I just installed a catch can is do to the fact that I track my fit constantly and canyon run. My fit runs constantly at high revs during long sessions. I have found about 3 table spoons of oil coming from the pcv line in my PRM instake every time I cleaned it at about 5k miles.
now here's question and need some clarification to... I'll quote what is relevant so as to we and the readers won't be back tracking throughout the pages...
is that a T fitting?
It should.. but how much air is actually bypassing the system is what will determine that.
I have seen people run their blow off valve to atmosphere because they like the sound (and maybe it gives them ricer street cred?) on cars where the MAF is pre-turbo so the majority will stall between shifts and at stop lights with a generally crappy idle.. but sometimes people can get away with it.
There is practice, and then there is theory. So, it is tough to say. As a general rule I would suggest not to do it.
So I guess try it? If you can get away with it go for it. But I am not sure what the benefit would be, aside from maybe cost advantage?
Depends on the car, and that cars configuration.
On our cars GE/GD, I would segregate them and plumb everything back into the system. YMMV
I have seen people run their blow off valve to atmosphere because they like the sound (and maybe it gives them ricer street cred?) on cars where the MAF is pre-turbo so the majority will stall between shifts and at stop lights with a generally crappy idle.. but sometimes people can get away with it.
There is practice, and then there is theory. So, it is tough to say. As a general rule I would suggest not to do it.
So I guess try it? If you can get away with it go for it. But I am not sure what the benefit would be, aside from maybe cost advantage?
Depends on the car, and that cars configuration.
On our cars GE/GD, I would segregate them and plumb everything back into the system. YMMV