[05wrx]

Originally Posted by jagstyle

So you are going to run three catch cans? one for each rocker cover and one for the pcv?

No, I was an idiot when I posted that. I've done much more research on the topic and realized I was dumb for even thinking that. I do have 3 catch cans running though.

1 for the two rocker cover vents before they go back into the inlet hose.
1 for the PCV vent to the turbo inlet hose.
1 for the PCV vent to the intake manifold.

For some reason, I am not catching a dang thing in my PCV vent to inlet hose catch can whatsoever. I catch a little in the rocker cover breather can, but I catch the most in the PCV vent to intake manifold. So much that I have to empty it pretty frequently in fact. I just changed my oil today and got to wondering about it all. I am considering deleting my PCV vent to the intake manifold if it's not catching anything.

Now, hopefully I won't get any crap for this but 2 of my catch cans are Home Depot air compressor filter style setups. The one on the intake manifold is a Husky and the one on the PCV valve is a Kobalt. I've checked them for leaks and made sure they're fine. They handle the heat and torture of an engine bay just fine. Going on 6000 miles so far with them. The one can off the breather vents is a Greddy ebay knock off though. It sucks.

So in conclusion I'm really guessing that the only catch can that's worth a darn is the one off the PCV/intake manifold setup. Why could/would this be? Possibly because I have an aftermarket turbo inlet hose and had to put a resistor in the factory connection there at the PCV vent to the hose? Maybe the ECU doesn't think it's attached? Weird.

[Deuce Cam]

^^Great idea, I think you're the first to do this. I've had the idea of running a 3 cc setup in the same manor for a while, but I'm still undecided on what I want to do.

Out of the following text that you posted I don't understand the line in bold, it doesn't fit with the rest:

I catch the most in the PCV vent to intake manifold. So much that I have to empty it pretty frequently in fact. I just changed my oil today and got to wondering about it all. I am considering deleting my PCV vent to the intake manifold if it's not catching anything.

So in conclusion I'm really guessing that the only catch can that's worth a darn is the one off the PCV/intake manifold setup.

Are you just looking to take the intake manifold line and cc out of the equation (i.e. plug the manifold) because it collects the most oil?

It's not surprising that the intake manifold pcv line gets the most oil. During off boost conditions - when the engine is in vacuum - the pcv valve opens and the oil has almost a straight shot from the crankcase into the intake manifold, completely bypassing the intake track. There's only 4-5 inches of hose between the crankcase fitting and intake manifold, it starts at 3/4" ID and necks down to around 1/4" ID about half way through.

Considering this, it's ironic that nobody ever puts a cc on the intake manifold line, they always put it on the pcv turbo inlet line and/or valve cover breather lines.

[jagstyle]

Originally Posted by 05wrx

For some reason, I am not catching a dang thing in my PCV vent to inlet hose catch can whatsoever. I catch a little in the rocker cover breather can, but I catch the most in the PCV vent to intake manifold. So much that I have to empty it pretty frequently in fact. I just changed my oil today and got to wondering about it all. I am considering deleting my PCV vent to the intake manifold if it's not catching anything.

These statements contradict, please clarify which of the three catch cans is collecting the most.

[SenseiL2007]

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[05wrx]

Originally Posted by Deuce Cam

^^Great idea, I think you're the first to do this. I've had the idea of running a 3 cc setup in the same manor for a while, but I'm still undecided on what I want to do.

Out of the following text that you posted I don't understand the line in bold, it doesn't fit with the rest:



Are you just looking to take the intake manifold line and cc out of the equation (i.e. plug the manifold) because it collects the most oil?

It's not surprising that the intake manifold pcv line gets the most oil. During off boost conditions - when the engine is in vacuum - the pcv valve opens and the oil has almost a straight shot from the crankcase into the intake manifold, completely bypassing the intake track. There's only 4-5 inches of hose between the crankcase fitting and intake manifold, it starts at 3/4" ID and necks down to around 1/4" ID about half way through.

Considering this, it's ironic that nobody ever puts a cc on the intake manifold line, they always put it on the pcv turbo inlet line and/or valve cover breather lines.

First off, I love your signature. I just have to say it. I tried using it over at ClubWRX and got in big trouble. I just think it's awesome.

Anyways, yea, I'm sorry for the typo there. What I meant was I was considering deleting the PCV vent to the turbo inlet hose as it is not catching anything

You're right about the intake manifold getting a straight shot of a few inches away from the PCV valve there, that's why I just figured I would see what it would do to put a catch can there. It seems to have made the biggest difference of them all. It catches the most oil (obviously the other two catch virtually nothing) and I'm sure that the black oil I see in the can can't possibly be good to be in the intake manifold. Correct me if I'm wrong.

Originally Posted by jagstyle

These statements contradict, please clarify which of the three catch cans is collecting the most.

Again, I'm sorry. What I meant to say was that the catch can I put between the PCV vent-to-intake-manifold is catching the most oil. The other two catch nearly nothing.

I don't know why this is, but there are no leaks (tested twice with air and smoke). The only reason I can conclude is that possibly since I put a resistor in the plastic nipple thing that used to be on the stock inlet tube (I have a Gimmick one now) that the ECU isn't thinking it's connected properly? Er, I may be way off and sounding stupid, so I'll stop there.

[kh15]

what do you guys think of this?
beatrush Gd Catch Tank ; Not Just Any Oil Catch Tank - NASIOC
im not sure how i feel about it dumping back into the oil pan, im thinking i would rather just get a catch can.

[Deuce Cam]

^^It looks pretty cool. They only thing is it only takes care of the valve cover breathers and not the crankcase vent. It looks like it does basically the same thing as the prova unit for less money. Even still, there's no reason that thing should be above $150 imo.

[tyler_sti]

^ +1 I'm seing the most blow by out of the crankcase.

[kh15]

thanks guys! great info! so i should really look into a crank case catch can?

[easyryder_28]

digging this up but this is for 05wrx

Anyways, yea, I'm sorry for the typo there. What I meant was I was considering deleting the PCV vent to the turbo inlet hose as it is not catching anything

does that mean your deleting your catch can circled in green on the previous page? any links to diagrams of the pcv system on the sti? ima catch can noob and just starting me research