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Discussion Starter · #1 ·
Ok, I know there are threads in the N/A area but some of you may not frequent over there..

with the GDi technology, combined with forced induction, the need for a catch can is amplified.

The reason being is that there is nothing to 'clean' the intake tract/valves anymore. These parts used to be cleaned by the fuel spraying. In a GDi engine, the fuel is sprayed directly into the combustion chamber, so the intake valves/ports don't stay as clean.

I have always been an enthusiast on using catch cans and after finding out the VTurbo is GDi even more for it.

Check out this article here:

GDI carbon buildup issue, and a solution « drivegeek

Now onto what catch can to use..

Of course there a bunch of different catch cans out there so it might be hard to choose what you want to get.

Before I go anywhere with this I would like to clear a couple things up. I would consider myself 'educated' about the topic and NOT an expert.

Also, ANY catch can is going to be better than NO catch can. The reason being, you will keep some oil/blowby from going back into the intake, even with a small, un-baffled, un-filtered can.

You may have seen catch cans all over ebay with their 'fancy' sight tubes, 'CNC machined' wording, 'TIG welded' (even though some have no welds) etc. and been like OMFG, must get CNC machined, tig welded can with a sight tube so I can constantly monitor the oil level. That is how they get people to buy their stuff, there isn't much point for any of this.

Are some catch cans better than others? OF COURSE. It all comes down to what you think is going to work for you, if you are modding your car extensively (creating more blow-by), racing the car, etc.

What I am going to recommend in this thread will be for 90+% of drivers who MAY increase their power output by 20% and spent most of their time commuting/spirited driving and not much on the track.
If you will be doing a lot of racing, adding a big turbo, running 250+hp you might want to consider a 'better' setup.

A lot of people have been recommending catch cans in the range from 75-200$ and I think that is absolutely INSANE.. Yes, they look good and yes, they will do a great job but you could save your self a bunch of money with VERY similar results.

The first ones I am going to suggest have been around for ages and work very well. The only thing you need to do is keep the filter element clean (clean it out every couple oil changes, or every oil change if you are accumulating a lot of oil)

I used this back in 2004 on my Turbo Tiburon and the entire time I had my '05 SRT-4 (2.5 years). I have also sold a few kits and customers have had great results.

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These are simple air filters for air compressors and cost from 10-22$ and include a very fine filter and a 'block off' to prevent oil flowing right from one end to the other.

You will also need NPT barbed fittings (~1$ piece) that match your hose size to hook these up.

I typically run them WITH the included filter, but some people run them without. It is arguable on how much you will really gain by having the filter installed or not. In theory, you will collect more oil and fluid if you keep the failter because the blow by that doesn't go through ends up condensing into liquid.



-Another good option is pretty much ANY ebay filter, with a few minor catch's like the ones below:

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These will all work good, as long as they don't leak AND you take a couple extra simple AND cheap steps.

The 'ebay' cans don't include any type of filter or baffling to prevent the 'mist/vapor' from going right in the inlet and then out the other side.

This is where SS scouring pads and a .20 cent check valve come into play.

You may have read up on this already, but if not, I will explain.

When there is blow-by from the car it is typically a mist of various densities.
If it is a dense mist, once it gets in the can, gravity does its work, preventing it all from going further down the intake tract.
If it is a very light mist, most of the flow will go in one side and out the other, preventing the can from doing much good
Here comes the point of the SS (Stainless ONLY) scouring pads, NOT STEEL WOOL. Get a couple SS scouring pads and pull them apart a little bit but DO NOT make it a bunch of pieces (this will help prevent any slim chance of the pieces getting in the engine) Taking this step alone will greatly improve the efficiency of the catch can while costing almost nothing and taking 5 minues of your time.

This is where you can go a step further to help keep your mind at ease and not worry about any of the scouring pad getting into the engine. It consists of a VERY cheap check valve and a piece of FG screen (like from your screen door) and something to keep the screen in place (super glue). This will make it all but impossible for any steel to end up in your intake tract.

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A piece of the screen will be glued in front of the catch can outlet. The holes in the screen are smaller than the SS pad strands so nothing will make it through.

The check valve would be placed after the can inline with the flow. This will prevent the can from being 'boosted' and ripping the screening off the inside of the can.



Both of these setups will work GREAT. You could probably skip the screen/check valve part but for those who are concerned about stray pieces of scouring pad (never heard of a single instance happening) this should ease your mind.

You could do a dual setup using either of the cans above and it would still cost much less than any of the 'engineered' or fancy catch cans.

I don't want to bash on any of these more expensive cans as they do their job VERY well, but there just isn't much practical purpose for them in the REAL world.

Some people will still want them because of the 'bling' factor or because they don't like to DIY things but other than that, there isn't a good justification (to me anyway) to go that route.

Either of the setups above will probably cost you a maximum of 35$ per can. This means you can set one up on your breather also (recommended as some vapor is vented through that location also) for less than 75$ and be assured that your intake tract will remain clean.

*As with any catch can setup, you will NEED to periodically check the level and empty the can. If the can is FULL, there is nowhere else for the vapor/oil to go and it WILL go into your intake tract*
 

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newbie question.. is the catch can necessary for a non-enthusiast who doesn't do mods and does no more than do regular maintenance of the car ?
 

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Discussion Starter · #3 ·
I would still put one on the car. You are going to be keeping blow by out of the engine, regardless of mods, which will keep the intake chamber and valves a bit cleaner. As intake valves get dirty (as well as the chambers) the flow is decreased as is the performance of the car.
 
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ok another noobie question , where does this go and what exactley is it doing, sorry for my stupidity
 

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Turbosocks, I just wanted to commend you on sharing this information. It's been a long time since I've seen open-ness like that on a forum, where a member openly shares the specs for a product he could be selling to other enthusiasts at a profit.

-Justin
 

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has anyone posted a pic of where the pvc valve is on the car ?
 

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Discussion Starter · #8 ·
I will be installing mine this weekend, so I wil do a write up.. the PCV hose looks like it will be a pain in the ass since it connects under the IM. I will probably cut it and put a coupler on the exposed side to fix this inconvenience..

here is where the areas that could use a catch can are located.

For the valve cover breather, I will not be installing a port on my SRI and will have the hose go to the catch can and outlet the other side to the atmosphere. I know, not enviro friendly but hardly anything will get through to the other side..



GREEN = PCV
RED = Valve cover breather
 

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Turbosocks...

Have you installed a BOV yet? If you have can you post a link to a video? I'm really curious about the way it would sound on a VT. Also, any recomendations for a good exhaust note? The stock one really sucks!!!
 

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Discussion Starter · #10 ·
yeah stock exhaust has no note.. LOL

installing the BOV today.
 

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Okay, Catch Can, BOV, etc. There are a few of us out here with our deposits down who could use a little more explanations. I don't understand what blowby is ? Is this out of the PCV ? What the heck is a BOV ? Blow off valve ?
 

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From what i "know" or think I know... the BOV is the blow off valve which dumps PSI atmospherically instead of back into the exhaust like a waste gate. This is set by a spring rate and when its open it gives off a cool sound..
and blow by "I think" is rogue gases and pressures that contain small amounts of unburnt fuel and oil particles, created by engine operation captured and rerouted back into the combustion chamber thru the PCV?. Or am I way off ..I never Google'd it or cared to. One would want to use a catch can to reduce the amount of "Oil" being returned to the valves and fuel mixing areas to prevent "gunk"......i think lol..
 

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Blow Off Valve........Officially known as a wastegate, its a valve used on turbochargers to allow the engine to get rid of excess pressure generated by the turbos in the lines. Prevents the engine from damaging itself.......... Oh and sounds really coooool! I had a BOV and Turbo timer on 3 mr2 turbos, 91,92,93(335hp to wheels/~450 at crank) and first gen WRX (315hp)........ a good starter mods on turbos AND relatively inexpensive...................... oh and SOUNDS REALLY COOL!
 

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do you thinh the instal of a catch can will void the warranty ?
 

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I know when I had a catch can on my S2000 I was amazed at how much crap ended up in the can. Great mod for sure.
 

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Ok. Lets just say I don't want to do the catch can install. Is there a way I can service those parts that lead to the performance degrade ? Is the catch can the only option ? I have never done these things and I am afraid I may screw things up. I would rather the dealer do some service that would alleviate this issue. On a broader note - why doesn't Hyundai offer this out of the box ?
 

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Great write-up FOR SURE! Thanks for the info and looking forward to the BOV pic install as well as the can install.
 

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Discussion Starter · #20 ·
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