# Catch can question



## the snake 87 (May 26, 2013)

Okay, right now I can't justify spending $430 on a BFI setup right now, since I also need to save for school.

My question is if anyone has bought a catch can from eBay or wherever, how did you hook it all up or what other fittings did you have to get? Or is it even worth the trouble?

I have the stock manifold btw


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## WhatNoGarnish (Jul 6, 2007)

I would also like to know, thanks for posting this. After cleaning off my MAP sensor 2 weeks, I really want to do this..

I was thinking of getting the 42DD or IE catch can and running my own hoses and fittings as well.


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## gugu1981 (Jul 25, 2011)

I have an SRI, so the connector on the manifold side of the PCV hose was already cut off. When I installed the catchcan, I cut off the connector on the valve cover side, and just hooked up some generic PCV hose from pepboys to the connector, and ran the connection through the catchcan. I also modified the catch can to add a long tube inside, drilled with some holes. Then i added scrubbing pads to catch the vapor. I also added a drain valve, but that's mainly because when I got the catch can, the bottom drain hole wasn't plugged, and i happened to have a valve sitting around.











Peter


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## HelloMyNameIs (Aug 2, 2011)

Hah, I bought one of the BFI can's as a drunk impulse buy. Worth it? Eh probably not. But hot damn it looks good in the bay...

Drink some brews, break out your wallet, and forget how much you spent! :beer:


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## gugu1981 (Jul 25, 2011)

the rubber PCV hose isn't as flexible as the braided hose, but if you run a longer PCV hose, you can route it better(than mine) too. Also, I think i reached out to BFI and see if they will sell me the connector on the valve cover side, and was shot down. I would've loved to run their connector with a braided hose too. Oh well.

As far as I see it, the hood is going to be closed 99% of the time, how it looks under the hood is not very high up on my priority list.


Peter


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## the snake 87 (May 26, 2013)

gugu1981 said:


> I have an SRI, so the connector on the manifold side of the PCV hose was already cut off. When I installed the catchcan, I cut off the connector on the valve cover side, and just hooked up some generic PCV hose from pepboys to the connector, and ran the connection through the catchcan. I also modified the catch can to add a long tube inside, drilled with some holes. Then i added scrubbing pads to catch the vapor. I also added a drain valve, but that's mainly because when I got the catch can, the bottom drain hole wasn't plugged, and i happened to have a valve sitting around.
> 
> 
> 
> ...


This is exactly what I needed!

Inside the catch can, was yours already baffled? And would those hoses inside of it even be necessary? I still planned on using steel wool inside of mine, but that part I'm a little lost on.


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## gugu1981 (Jul 25, 2011)

The cheap ebay cans are not baffled. The inside hose is added to force the vapor to travel down and through the scrubbing pad, instead of stay at the top of the can, in one port and out the other.

My catch can came with that clear hose, whose exterior diameter is a perfect match for the interior diameter of the port (very very tight fit, no chance of vapor blow by on the exterior of that hose)


Peter


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## the snake 87 (May 26, 2013)

gugu1981 said:


> The cheap ebay cans are not baffled. The inside hose is added to force the vapor to travel down and through the scrubbing pad, instead of stay at the top of the can, in one port and out the other.
> 
> My catch can came with that clear hose, whose exterior diameter is a perfect match for the interior diameter of the port (very very tight fit, no chance of vapor blow by on the exterior of that hose)
> 
> ...


I just found that same can and added it to my watch list. In essence then, the tube acts as a baffle then? Pretty smart. I like that and will probably do the same then. Could you tell me the size of the fittings for the hoses so I can find different ones? I'm on Intergrated Engineering's site right now and plan to purchase their boost cap and breather adapter as well.


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## gugu1981 (Jul 25, 2011)

The size of the hose will depend on the fitting on the catch can. 
For example, this listing provides 2 sizes, so you will have to pick the hose accordingly.



I believe the connector at the valve cover side takes 3/4" ID hose. I had to run a reducer on the intake manifold side because my SRI has a smaller fitting.


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## the snake 87 (May 26, 2013)

gugu1981 said:


> The size of the hose will depend on the fitting on the catch can.
> For example, this listing provides 2 sizes, so you will have to pick the hose accordingly.
> 
> 
> ...


Oh sorry I was referring to the thread size on the fittings themselves haha, not so much the hose size. My bad. Do you know that?


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## gugu1981 (Jul 25, 2011)

sorry, I do not know that. I used the fittings that came with the can, and didn't mess with that part.



Peter


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## Matti von Kessing (Jan 17, 2011)

the snake 87 said:


> Okay, right now I can't justify spending $430 on a BFI setup right now, since I also need to save for school.
> 
> My question is if anyone has bought a catch can from eBay or wherever, how did you hook it all up or what other fittings did you have to get? Or is it even worth the trouble?
> 
> I have the stock manifold btw


Help me out here: why on earth would anybody spend $430 on a solution to a problem that doesn't exist on a low compression, port injection, naturally aspirated engine? Engine decor?


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## the snake 87 (May 26, 2013)

Matti von Kessing said:


> Help me out here: why on earth would anybody spend $430 on a solution to a problem that doesn't exist on a low compression, port injection, naturally aspirated engine? Engine decor?


I guess decor, but it's not like it doesn't have a purpose...

Hence why I don't feel like a catch can system is worth $450 especially since I can piece and make my own for $150 or less...

Plus a catch can allows us to delete our vacuum pumps and what not. Again, it's not like it doesn't have a function.


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## le0n (Jun 12, 2013)

Matti von Kessing said:


> Help me out here: why on earth would anybody spend $430 on a solution to a problem that doesn't exist on a low compression, port injection, naturally aspirated engine? Engine decor?


cleaner plenum. some of our 2.5s get a build up of oil that drops out of the crank-case vapor. in turn, the oil gives false manifold absolute pressure readings by interfering with the MAP sensor.

i'm not sure that the reason for these guys doing it, however, this is why i want to do it.


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## gugu1981 (Jul 25, 2011)

le0n said:


> cleaner plenum. some of our 2.5s get a build up of oil that drops out of the crank-case vapor. in turn, the oil gives false manifold absolute pressure readings by interfering with the MAP sensor.
> 
> i'm not sure that the reason for these guys doing it, however, this is why i want to do it.


Yup, even on a stock car, there is enough vapor to coat the MAP sensor in oil, I imagine the rest of the intake manifold is coated too. On SRI equipped cars revving to 7300rpm, it's a bit worse than stock cars. For about $60 (if you don't go all fancy with the connectors), I think it's worth the peace of mind.

PLUS, I have my eyes on a snail already, so this is all part of the prep work.


Peter


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## the snake 87 (May 26, 2013)

gugu1981 said:


> Yup, even on a stock car, there is enough vapor to coat the MAP sensor in oil, I imagine the rest of the intake manifold is coated too. On SRI equipped cars revving to 7300rpm, it's a bit worse than stock cars. For about $60 (if you don't go all fancy with the connectors), I think it's worth the peace of mind.
> 
> PLUS, I have my eyes on a snail already, so this is all part of the prep work.
> 
> ...


Yup. Mine is not really modded (05.5 w/ MAF), but while I replaced my vacuum pump I took a peak inside the manifold through the exposed throttle body and saw the inside was coated in a layer of oil. Plus today I unclipped that air return/separator tube that goes from the valve cover to the manifold and there was a lot of oil inside.

Even if it's not a heavily modded car, it's all for peace of mind and maintenance as well.


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## WhatNoGarnish (Jul 6, 2007)

So on a stock manifold, where can we plumb the return hose?


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## gugu1981 (Jul 25, 2011)

WhatNoGarnish said:


> So on a stock manifold, where can we plumb the return hose?


i cannot remember 100% whether the connector on the manifold side is re-usable, i would imagine it is. So I would cut the stock PCV hose, cut off the corrugated plastic hose, salvage the 2 connectors. Then you should be able to use generic rubber PCV hoses (with the right inside diameter) from pepboys, attached to each of the connectors.


Here's a picture borrowed from a manifold removal DIY thread, showing where the manifold side of the hose connects to (under the throttle body)
https://lh3.googleusercontent.com/-bSJL3d-I8U8/UXyoAD9x3vI/AAAAAAAACsM/X1xECYGBB8k/w800/IMG_4685.JPG


And here's the full DIY thread, showing how much oil is in the manifold and on the MAP sensor on a car with just an intake.
http://volkswagenownersclub.com/vw/...DIY-2.5L-MKV-Intake-Manifold-Removal-Cleaning



Peter


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## the snake 87 (May 26, 2013)

WhatNoGarnish said:


> So on a stock manifold, where can we plumb the return hose?


Or get Integrated Engineering's boost cap, that way you can either use a threaded connection or barb if you want. $40 though :/ but it'll be clean. I plan on using that and their breather cap adapter as well which is another $40.


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## gugu1981 (Jul 25, 2011)

the snake 87 said:


> Or get Integrated Engineering's boost cap, that way you can either use a threaded connection or barb if you want. $40 though :/ but it'll be clean. I plan on using that and their breather cap adapter as well which is another $40.


yah, that'd be the fancy solution. You'd also need/want nice hoses with AN hose ends(you will need 2 hoses and 4 ends, to and from the catchcan). Look at another $60-80 for that. That puts you at $140-160 for the connection. Will definitely look pretty though. 


Peter


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## the snake 87 (May 26, 2013)

gugu1981 said:


> yah, that'd be the fancy solution. You'd also need/want nice hoses with AN hose ends(you will need 2 hoses and 4 ends, to and from the catchcan). Look at another $60-80 for that. That puts you at $140-160 for the connection. Will definitely look pretty though.
> 
> 
> Peter


Yup! That's the plan! Already have everything all priced out now actually. Just waiting for some extra cash.


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## gugu1981 (Jul 25, 2011)

looking at the IE boost cap/tap, i'm not sure how well it will work. The opening is very small, and it will come with a barbed fitting. Have you talked to IE to see if they can supply a different fitting? The breather adapter is a humongous(relatively) 10an, so if fitting on your catchcan is anything smaller than a 6an, it's going to increase the velocity significantly. Not sure if the velocity generates enough turbulence to reduce the effectiveness of the baffle. Just some items to think about as you are piecing it together.


EDIT:
http://www.performancebyie.com/integrated-engineering-boost-tap-for-fsi-tsi-and-2-5l-5cyl-engines
this will work. $5 more, but is designed to work for the PCV system, in addition to a boost gauge (you can cap that if you are not boosted)


Peter


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## the snake 87 (May 26, 2013)

gugu1981 said:


> looking at the IE boost cap/tap, i'm not sure how well it will work. The opening is very small, and it will come with a barbed fitting. Have you talked to IE to see if they can supply a different fitting? The breather adapter is a humongous(relatively) 10an, so if fitting on your catchcan is anything smaller than a 6an, it's going to increase the velocity significantly. Not sure if the velocity generates enough turbulence to reduce the effectiveness of the baffle. Just some items to think about as you are piecing it together.
> 
> 
> EDIT:
> ...


I planned on getting just the cap and getting a thread adapter to go from whatever is on the cap to an AN 10 thread. Because in reality, even if it decreases the effectiveness of the catch can, it's still better than the stock setup regardless.


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