[Kevin]

Okay so I'm a bit curious. I understand that a single catch can will catch the blow-by that comes out of the PCV valve, filter it, and send it into the air intake tubing.

But what does a second one do? Does the car have two PCV valves or ..

 

[Switt23]

One Catches from the PCV to the Intake Manifold, the other should be from the Valve Cover to the Intake...

Forgive me if my verbiage is incorrect. Essentially there are two lines that VT owners are filtering out Blow-By for. PCV is worse than the Intake

 

[mehringe]

PCV catches more than the intake but any intake blow by goes through the intake tubing, turbo, hot pipe, intercooler, and cold pipe and results in a coat of oil on all of those components.

 

[Incognito]

Just vent the top one to atmosphere. Don't hook it back up to the intake, catch can or not.

 

[Kevin]

Just vent the top one to atmosphere. Don't hook it back up to the intake, catch can or not.

Is there a reason for this?

Also which side is the "top one" should I hook one of these up to it? ADD W1 Black Baffled Universal Aluminum Oil Catch can Reservoir Tank Ver.2 | eBay

 

[rspec2014]

I would avoid ebay cans... the top one is the valve cover that people will vent. but vent to atmosphere after you go through a catch can.

 

[btalont]

Dual cans are a must. I typically have about 4-5 oz of oil in the PCV can and an oz or so in the valve cover breather hose between oil changes (4000 miles) I have the 6th element kit..outstanding quality parts.

 

[geekdragon]

The PCV catch can gets little argument from me, but I'm still of two minds about the valve breather catch can. It's ridiculous to let oily junk go into the intake, but if the breather is vented to atmosphere (like most suggest) the only reason to worry about a can is to reduce the fumes and mess.

I got really pissed off with the off-gassing smell from my vented breather, moved the outlet several times, and ended up reattaching the loop to my intake out of desperation. In this case, the catch can might actually be doing something -- reducing the damage. If the breather is vented to atmosphere, holding the residue back to dump later seems like an necessary step.

 

[leesrt]

You can vent the breather to atmosphere but you have to route a longer hose to a place where it's away from the engine bay. It also needs to be somewhere where oil drippings is ok.
That's why I have a dual catch can set up. My breather side catches a good bit of fuel oil mix by every oil change. A good bit being a few tablespoons. If the open end of the breather hose, even if going through an OCC, is anywhere in the engine bay you are going to get fumes in the passenger compartment. The only way around it is to get a longer fuel hose and route it down under the car. I put a breather filter on it to keep things from crawling back up the hose. The filter isn't needed but I had one so used it. A simple mesh screen on the end of the hose would have done the same.

If you don't know how the PCV system works with the breather system I suggest you do some reading, Google searching, YouTube watching, whatever before you make changes to the system. You need to understand what you're doing before you do it.
Don't be the ricer that just puts shit on your car because it's what the other guy did.

 

[Kevin]

You need to understand what you're doing before you do it.
Don't be the ricer that just puts shit on your car because it's what the other guy did.

I learned all about the PCV system when my miata's pcv hose snapped in half and it needed replacing.

What I don't get is why somebody would let gross oily air out of that small filter that would just clog up eventually.

If somebody could show me a picture of their setup .. It would help a bunch

 

[rspec2014]

The PCV or valve cover line has to go through a catch can first... on the valve cover the outlet of the can can go to a breather... the PCV exit recirculates back to the engine.

 

[leesrt]

I learned all about the PCV system when my miata's pcv hose snapped in half and it needed replacing.

What I don't get is why somebody would let gross oily air out of that small filter that would just clog up eventually.

If somebody could show me a picture of their setup .. It would help a bunch

Your original post indicated you didn't know.

The filter, screen, what ever you use won't clog. It's oil/fuel vapor, it flows through the mesh quite easily. There's also a thing called "maintaining your car" where you check on stuff like that.

My previous comment didn't say you "were" a ricer, it said don't become one. I see to many posts with people wanting advice on how to use, install, set up this new mod they got. The information is readily available to become highly knowledged on any mod you chose to do. I'm just saying study before you do.

The PCV and breather circuit work hand in hand depending on whether you're in vacuum or boost.

 

[Kevin]

I did search around, but I had additional questions which I why I made the post.

I appreciate your reply because now I don't have to research into the wrong products.

I'm not doing this to be like other members. I'm heavy into preventative maintenance and simply just curious because I want to take care of my engine ASAP (since I have a long daily drive commute) I can't imagine somebody would actually buy a catch can for appeal instead of protection. You barely see them anyways unless its a SXTH

 

[leesrt]

I did search around, but I had additional questions which I why I made the post.

I appreciate your reply because now I don't have to research into the wrong products.

I'm not doing this to be like other members. I'm heavy into preventative maintenance and simply just curious because I want to take care of my engine ASAP (since I have a long daily drive commute) I can't imagine somebody would actually buy a catch can for appeal instead of protection. You barely see them anyways unless its a SXTH

You'd be surprised, just look at all the fancy colored OCC's on ebay.

I have never felt a car needed OCC's more than this one. There are others here with much more knowledge abut LSPI than I ever will but just from the accumulated oil I've poured out of those things, I wouldn't run this car without them. I to can testify that my pipes are clean all the way from the output of the turbo to the throttle.

 

[swordfish]

The valve cover, when not exposed to an external vacuum produces hardly any waste oil. I had mine attached to a 8" hose and filter on the end. It would start to look gummy every other oil change, a quick rinse and back on. It never once blew oil onto the transmission it was hanging over.

 

[leesrt]

The valve cover, when not exposed to an external vacuum produces hardly any waste oil. I had mine attached to a 8" hose and filter on the end. It would start to look gummy every other oil change, a quick rinse and back on. It never once blew oil onto the transmission it was hanging over.

I think the breather side is more vaporized so the airflow down there may prevent it from appearing on the transmission. Each car is different and I know my car accumulates a good bit in the can and the breather filter on the end of my hose always has residue on it. When my car was on the dyno last year my breather filter was just off the stock hose with no OCC and on each run I could see a puff of vapor each time you let off on the throttle. It is much less than the PCV side, I would say half, but saying it hardly produces makes it sound like it's not that important. The PCV side is just routing that crud between the manifold and valve cover. The breather side takes the crud through the whole turbo system and then the manifold.

 

[Stacyj917]

If you vent to atmosphere, what to do with the inlet to the CAI/SRI? How do you close that off if there isnt anything connected to that part of the system?

 

[trdtoy]

A vacuum cap from an auto store