Installing ETS 3.5in FMIC this wknd and would like to make the call on either:

a) A catch can which can cost a bit, connected back to the intake since I am told from one friend "the suction of the turbo helps evacuate the gasses/vapors from the crankcase during boost conditions yielding a more efficient engine. Plus, an open breather with just a filter won't pass tech at some tracks since it poses a risk of putting oil on the track. Not much oil comes out of the breather unless your rings are shot so I don't think you need to worry too much about filling your intercooler with a film of oil. I just like keep it connected to the intake since."

or

b) A simple, cheap, breather filter: http://tinyurl.com/oo99ht, because again, it's cheap, and I don't want ANY oil inside my FMIC. Plus a different, respected friend recommends this solution. haha.

Thoughts? I do plan on taking the car to HPDEs, so not sure about my friend's comment about open breather filter not being allowed. but it is a concern.

Thanks!

 

I am not an engineer nor have I done any tests. But what I have done is searched the living crap out of this topic. Here is what I concluded and the reasons why....

https://www.evolutionm.net/forums/ev...-breather.html

Lets remember where this crank pressure comes from. Key word crank.

So there is no real ventilation effect there. Blow-by from the pistons accumulate and get pushed out to the top of the valve area. The blow-by contaminates the oil regardless. This contamination is part of the main reason why need to change our oil.

The stock pcv vacuum routing is designed to keep a closed system from allowing blow-by contamination onto the atmosphere (Emissions reasons).

Some really big drag cars might run a venturi effect pcv system or motor/belt driven vacuum pumps because they push soo much blow-by that vacuum assistance is needed to maximize for clearing it and increasing power output. And then some really big build project cars may have multiple breather ports on their valve cover to allow more gases to escape.

The breather filters might get some oil because of oil vapors with the blow by gas. But you could get one of those cheap catch cans that are not sealed and have a breather on them. This would then have a place for some oil vapors to collect while venting to atmosphere.

If it makes a difference, I'm currently venting to atmosphere with no breather filters. Eventually I'll get a catch can with a built on breather for some of the vapor oil to collect. Oh and on top of that make sure to remove the check valve so the pressure can be relived much easier from the valve cover instead of have to build slightly to push it open.

 

what about using huge AN lines for PCV and breather going to a catch can? any advantage to this?

 

the check valve? you mean the PCV valve that screws into the valve cover?

 

I personally run MAP's Crankcase Vent set with a catch-can (loosely packed with copper wool) , all routed back to my intake pipe. During idle/cruise, the vacuum from the intake manifold helps to evacuate crankcase gasses and vapors, but once you hit boost the PCV valve snaps shut. An open filter on the breather tube works, no doubt about it. But, I personally opted to go one step further by not only allowing the pressure to escape, but to help evacuate it similar to how the car is setup stock to do so. Here is a picture of my setup:

breather tube -> MAP Vent -> catch-can -> intake pipe

 

Correct. The pcv valve is actually a "check valve". It opens during vacuum and closes during boost.

 

[QUOTE=S2kracka;7063449]I personally run MAP's Crankcase Vent set with a catch-can (loosely packed with copper wool) , all routed back to my intake pipe. During idle/cruise, the vacuum from the intake manifold helps to evacuate crankcase gasses and vapors, but once you hit boost the PCV valve snaps shut. An open filter on the breather tube works, no doubt about it. But, I personally opted to go one step further by not only allowing the pressure to escape, but to help evacuate it similar to how the car is setup stock to do so. Here is a picture of my setup:

breather tube -> MAP Vent -> catch-can -> intake pipe

[QUOTE]


So your still running the pcv line to the intake manfild? If so then your still pulling in oil vapors into the intake manifold. Your intercooler might be clean from oil (for the most part) but the air going into your intake manifold is not.

 

Correct. I need to get a catch-can between my PCV and intake manifold sometime. Since its just sucked into the engine during idle/cruise I'm not too worried about it though. My intake manifold has been staying very clean since I blocked off the EGR.

 

A breather valve is a vaccum leak. Not a big one, but it is infact, a vaccum leak.

Run a small inline fuel filter. This is cheap, affective, and slightly ghetto BUT, the filter is so small, you can hide it in a remote location so it can't be seen I ran these for a long time and they always did the trick. They're $2 and you need to replace them once an oil change.

When I first bought the car, the intake tube was full of sludge. I used one of these little fuel filters and never saw an ounce of oil in the intake ever again. It was trapped in the filter, which is clear, so you can see it working There is so need to spend $100 or so on a catch can on the breather side of the engine. Do the math, even though you need to replace the filters every oil change (3000 miles) it'll take up to 150k mile to cost $100 in fuel filters But, I do infact recommend spending the money on a catch can the PCV side. It needs to hold pressure, and the PCV side ALWAYS has more oil pass through.

 

Ist the EGR on JDM/Euro evo's only? (the part that recirculate exhaust into the intake manifold) How is it that your car had an EGR?

 

I currently have a Saikou Michi Dual Oil catch can. It goes from the pcv valve to catch can and then back to intake manifold, so oil gets collected at the catch can. And for the breather side, it goes from the breather side to catch can and then just vents to atmosphere because I don't want any oil going back to intake. I know the catch can catches most of it, but I've still seen a little in the intake tube now and there, but it's def a lot less than before. This seems to work.

 

After much thought, I decided to just run the hoses from the PCV valve/VC driver side port to one catch can with a breather on the top. The hose routing back into the intake manifold from the PCV valve is simply there for emissions purposes. Since I run no emissions provisions, no sense in filling my intake mani with hot crankcase air.

I'm on AEM ems btw, for my stock ECU/stock intake manifold folk, I'd suggest keeping it routed the same with a catch can in between both.

 

I'm on stock ecu. It doesnt matter what ecu you are on as long as you dont set it up in a way to pull in air thats not metered by the maf. Example: 1 breather on driver side with stock pcv to manifold connection.

 

Bryce,
It's definitely a good investment IMO. Like S2kracka I've also replicated the stock setup except I've also got a can running on the PCV side. I'm running a Saikou Michi DC3 dual chamber catch can and I couldn't be happier. His site has lots of great information if you'd like to learn more about blow-by.
-Alex@ECS