# 24v vr6 Catch Can



## 1broknrado (Jul 6, 2005)

Hi All,

As I am coming closer and closer to finishing my 24v vr6 swap on Lugtronics in my Corrado, I would like to talk about catch cans. How have you guys mounted your catch cans? Which brand have you gone with? Did you use a sealed or unsealed system? How often do you empty out the catch can with either system??

I have it in my head that I want to use a sealed catch can in order to eliminate any oil smells, however, I have been told I may want to recirc the catch can back into the oil pan as there is an issue with the baffles in the VC. Since there is not adequate baffle in the VC, there will be a WHOLE LOT of oil residue being dumped into the catch can and I will have to empty it out with every gas tank fill up. Don't quote me on this, this is just what I've been told. 

Thanks for any input and pictures!

Best,
Tim

PIX FOR CLICKS!


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## xtremevdub (Jun 26, 2004)

It almost seems like you dont understand the purpose of a catch can.
You use a catch can to eliminate oil vapors going back to your intake manifold and burning in the pistons.. Oil Vapor can cause detonation. 
Plus it gets all the inside of your intake manifold covered in oil. 
Oil Vapors/pressure are generated from the block and VC when the engine works.

So you put a catch to remove the PRESSURE and oil vapor from Valve cover and the block, if you dont relieve the pressure, you end up with blow by. And the VC may have so much pressure that you will see oil coming out of the seals. Not good. 
So you either rout the catcan back into the intake (sealed catcan), or buy one with a filter on top so it relieves the pressure to atmosphere. 
On either you could have a hose in the bottom so you can send oil back into the oil pan. 
If you are gonna have a hose back into the pan, you wanna mount your catchcan high on your bay.. :thumbup:


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## Jo|\| (Jul 3, 2011)

Our setups are very different so I don't know how much this will help, but here is my setup.

I'm running a MK5 valve cover with a AN fitting welded on connected to a 42DD catch can. The mounting bracket for the can is welded to the upper strut brace I drain about a cup every month. The return on the top still isn't hooked up so the occasional oil smell comes into the cabin. I would like to route the outlet back into the intake but since I'm supercharged the air intake is in front of the passenger wheel liner. In the end I'll probably just run a hose to the ground instead of running it all the way across the engine bay.


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## 1broknrado (Jul 6, 2005)

xtremevdub said:


> It almost seems like you dont understand the purpose of a catch can.
> You use a catch can to eliminate oil vapors going back to your intake manifold and burning in the pistons.. Oil Vapor can cause detonation.
> Plus it gets all the inside of your intake manifold covered in oil.
> Oil Vapors/pressure are generated from the block and VC when the engine works.
> ...


This is what I had believed. The issue with the filter on top was I wanted to eliminate the smell all together. I've seen pictures with people who have two AN lines coming from their VC going to the catch can in order to create a sealed environment, correct? If you look at say the FSI r32 catch can, it reroutes back into the VC with no filters on top. 

If it is as easy as just putting a catch can on the pass side and putting a filter on the top to eliminate the smell, then I'll do that. I had just figured it needed to be somehow connected back into the VC. 

How I thought the Catch can needed to be connected to the VC in order to be a sealed setup to eliminate 100% of oil vapor smell:


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## xtremevdub (Jun 26, 2004)

1broknrado said:


> This is what I had believed. The issue with the filter on top was I wanted to eliminate the smell all together. I've seen pictures with people who have two AN lines coming from their VC going to the catch can in order to create a sealed environment, correct? If you look at say the FSI r32 catch can, it reroutes back into the VC with no filters on top.
> 
> If it is as easy as just putting a catch can on the pass side and putting a filter on the top to eliminate the smell, then I'll do that. I had just figured it needed to be somehow connected back into the VC.
> 
> How I thought the Catch can needed to be connected to the VC in order to be a sealed setup to eliminate 100% of oil vapor smell:


Well, I hear you about the smell. but even on a factory car you dont see any AN fittings on something so simple.. plus the amount of air/vapor is not not much, is the accumulation of pressure is what causes issues. That whole AN fitting thing is there only for looks, nothing else. 
Also, the lines go from VC to catchcan to intake. The setup on that FSI R32 is going into the VC but is more than it meets the eye.. so I believe that internally routes to the Intake anyways.. I think I saw a diagram somewhere. Again, since you are NOT running that engine, it doesnt matter in your case. 










http://www.saikoumichi.com/

http://www.saikoumichi.com/DC3_page.htm
^^^^ Killer setup for your car. One individual catchcan for VC and Crank case. :thumbup:


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## 1broknrado (Jul 6, 2005)

*FV-QR*

That looks like a great product, however I am running the SRI which has no inlet for the return from Catch Can. Are my only options to tap into the SRI and make an inlet or just run a catch can that has a filter on the top.


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## 1broknrado (Jul 6, 2005)

*FV-QR*

http://www.performancebyie.com/integrated-engineering-billet-catch-can

Probably will end up using that catch can with a few AN fittings. Thoughts?


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## xtremevdub (Jun 26, 2004)

The one above can be made for like 10 bucks man.. 
Stick some







in a can, make two outlets and you get the same performance, if not better. 

And you dont have to drill the intake manifold :facepalm: you just route it after the air filter somewhere..

This is a much better design and comes with the AN fittings. http://www.youtube.com/watch?v=WJfwc6tMoSc

Maybe this picture will answer how to route it. 









^^^Again, this is for a sealed system, you dont need a catchcan with a filter on top.


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## 1broknrado (Jul 6, 2005)

My intake is cone filter to TB then manifold. No space inbetween them. 

I understand how to route it back to intake manifold, just think it would be easier for me to use a regular atmosphere vented can since I don't have a location to go back into the manifold with, correct? 


Sent from my iPhone using Tapatalk


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## Yareka (Mar 5, 2002)

You are overthinking the catch can Tim :wave:
The standalone guys not running a maf usually arent running an inlet pipe, like you and me. So there is no source of vacuum unless you use just the intake manifold, which sucks because when you have the most amount of blowby(under load) there will be no vacuum pulling on the tank. Simply run a catch can with one line going to your valve cover and another line that drops below subframe. The can will ventilate but not up near the raintray where you will smell it all day. 

If you really want do it right, follow this and finish where I left off
http://forums.vwvortex.com/showthread.php?6875603-Electric-Crankcase-Evacuation


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## 1broknrado (Jul 6, 2005)

Yareka said:


> You are overthinking the catch can Tim :wave:
> The standalone guys not running a maf usually arent running an inlet pipe, like you and me. So there is no source of vacuum unless you use just the intake manifold, which sucks because when you have the most amount of blowby(under load) there will be no vacuum pulling on the tank. Simply run a catch can with one line going to your valve cover and another line that drops below subframe. The can will ventilate but not up near the raintray where you will smell it all day.
> 
> If you really want do it right, follow this and finish where I left off
> http://forums.vwvortex.com/showthread.php?6875603-Electric-Crankcase-Evacuation


Hi Kevin,

I'm trying to make this as simple and clean looking as possible without spending $250 on that super awesome Mishimoto catch can. Do you ever have issues with the vent under the subframe spraying oil under the car? I know with any oil leak i've had, you can tell instantly by looking at the back of the car covered in oil :banghead:


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## Yareka (Mar 5, 2002)

No issues with the "draft tube" collecting on the back bumper. You *might* notice it more on a white car but there would be more more coming from the exhaust than coming all the way back to the rear from the subframe hose. Any oil leak that you have will cause way more of a mess than your crankcase tube since most of it is vapor.


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## 1broknrado (Jul 6, 2005)

*FV-QR*

Perfect. Now I need to figure out a clean install method. thanks for the advice :thumbup:


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## Yareka (Mar 5, 2002)

No problem Tim.
Great place to mount a can in the rado is right at the firewall behind the passenger rear motor mount. In your picture above if you look directly down where the valve cover vent is located, mounted under your brake line on the firewall. Ideally you'd chop off that crazy huge fitting on the valve cover and tap for 1/2 or 3/4" npt. Then do -12an line down with a 45* degree fitting down to the catch can. Other, lower fitting on can gets looped around under the frame rail/subframe. Another great part about mounting the can there is that it stays hot, moisture burns off instead of filling up the can :thumbup:

Kinda like the -an fitting this guy did on his valve cover but you can do it much cleaner by pointing it down toward the can and you have a lot more room. And please use black fittings


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## 1broknrado (Jul 6, 2005)

Yareka said:


> No problem Tim.
> Great place to mount a can in the rado is right at the firewall behind the passenger rear motor mount. In your picture above if you look directly down where the valve cover vent is located, mounted under your brake line on the firewall. Ideally you'd chop off that crazy huge fitting on the valve cover and tap for 1/2 or 3/4" npt. Then do -12an line down with a 45* degree fitting down to the catch can. Other, lower fitting on can gets looped around under the frame rail/subframe. Another great part about mounting the can there is that it stays hot, moisture burns off instead of filling up the can :thumbup:
> 
> Kinda like the -an fitting this guy did on his valve cover but you can do it much cleaner by pointing it down toward the can and you have a lot more room. And please use black fittings


IE sells an AN fitting that gets tapped (with mallet) right into the VC making -8an lines. I was planning on mounting it right behind the pass side headlight because I was told the can needs to be higher or at the same level of the VC. I'm definitely going to look into my mounting options going that route as it would save me a lot of $$ in braided hose and AN fittings 

Thanks Kevin!


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## 1broknrado (Jul 6, 2005)

1broknrado said:


> IE sells an AN fitting that gets tapped (with mallet) right into the VC making -8an lines. I was planning on mounting it right behind the pass side headlight because I was told the can needs to be higher or at the same level of the VC. I'm definitely going to look into my mounting options going that route as it would save me a lot of $$ in braided hose and AN fittings
> 
> Thanks Kevin!



Kevin,

Not sure if this would interest you but instead of running the hose to the ground instead of the TIP, I think I'm going to go with venting it back into the exhaust. 

http://vibrantperformance.com/catalog/product_info.php?osCsid=f2b55e4334890725b85a8bffe5c6bcf1&products_id=1243&cPath=1022_1035_1069

Mounted on the rear motor mount, then have a little hose going into the exhaust (post wideband) with that check valve installed in the system so that when you are getting on it, it pulls vac from the exhaust pressure instead of the TIP. 

God I love searching. It's like undigging little pots of gold everytime I find something useful!


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## Yareka (Mar 5, 2002)

I tried that idea a few years ago and it worked at idle and low revs. But between 4500 and 5500 the exhaust fitting would actually create positive pressure which you never want to have pressure on the crankcase as your gaskets will leak. I have heard that you may get lucky but if you do this you must put a vacuum guage on the line to make sure you are not creating that pressure there. There is a science to putting the venturi in the right part of the exhaust after a bend and some say that this is only meant for open headers with no mufflers. If you read the link I sent you above, I was able to make 5" vacuum with the secondary air pump on my car.


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## 1broknrado (Jul 6, 2005)

*FV-QR*

Hmmm. Maybe the answer would be to put that venturi valve into the exhaust and also have a filter on the top of the can, that way when/if positive pressure is created, it can escape through the filter instead of building up backpressure?


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## 24vGTiVR6 (Sep 14, 2010)

usually older US muscle cars with open exhausts use this type of evac scavenger setup - and it works well, but isn't ideal with most of our cars. also as Yareka stated the placement and angle of the fitting matters a TON. personally I'd stay away from the whole thing. dump it low past the subframe or re-route into the turbo inlet pipe.

I'd also stay away from dumping the catch can contents back into the oil pan. it's full of the stuff you DONT want in your motor.


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