2G Oil Catch can questions

[Allen2g]

Just wanting to make sure, ive read many threads and all the answers were either do it or dont do it so im confused now .
I bought a 3 port baffled catch can (mishimoto rep) was wanting to replace the pcv with a free flowing barb fitting then run a line from that to one of the 'in' ports on the can, then run the breather port to the other 'in' on the catch can, then the 'out' port on the catch can to the turbo intake pipe nipple as the vacuum.
Is that route optimal?
The other way i was thinking of doing it is keep the stock PCV system, seal off one of the 'in' ports on the catch can making it a 2 port can. Then just run a line from the breather port to the can, then a line from the can to the intake pipe.
wanting to note, this is a daily driven 2g.

thanks in advance!

 

[rEclipserGST]

https://www.dsmtuners.com/threads/the-4g63t-pcv-system.366890/

 

[CORNF3DECLIPSE]

Picture attached is what i think you described. Its a good setup.

 

[Allen2g]

Picture attached is what i think you described. Its a good setup.

Yeah, exactly that setup but i read that "Is crankcase pressure really high enough to warrant bypassing the PCV valve and running extra VC lines? Measure it!"
My crankcase pressure is not too high where my dipstick pops out so i gave a it a second thought and maybe a single line from the breather port to the catch can then a line from the catch can to the intake pipe would be better so i can keep the stock pcv system.

basically this setup with stock pcv system
or is it okay for me to go with the first initial setup for a DD?

 

[rEclipserGST]

Yes. Just run a check valve inline behind the factory PCV anyway. They almost always leak from factory.

https://www.google.com/search?q=dsmtuners+check+valve+pcv&tbm=isch&source=iu&ictx=1&fir=0aIXSdJNYGF1xM%3A%2C8GcnzRKB6aYtjM%2C_&vet=1&usg=AI4_-kTYll0DAzwIroIbE2LgsOT5ISESNQ&sa=X&ved=2ahUKEwi5_OPxjPvgAhUqmeAKHZ6NB-MQ9QEwAnoECAUQBA#imgrc=0aIXSdJNYGF1xM:

I am running two cans. Two lines from each. PCV behind the cans, then the check valve before the line hits the intake manifold.

I daily my car.

 

[Allen2g]

Yes. Just run a check valve inline behind the factory PCV anyway. They almost always leak from factory.

https://www.google.com/search?q=dsmtuners+check+valve+pcv&tbm=isch&source=iu&ictx=1&fir=0aIXSdJNYGF1xM%3A%2C8GcnzRKB6aYtjM%2C_&vet=1&usg=AI4_-kTYll0DAzwIroIbE2LgsOT5ISESNQ&sa=X&ved=2ahUKEwi5_OPxjPvgAhUqmeAKHZ6NB-MQ9QEwAnoECAUQBA#imgrc=0aIXSdJNYGF1xM:

I am running two cans. Two lines from each. PCV behind the cans, then the check valve before the line hits the intake manifold.

I daily my car.

thats the thing, i dont want to be running two catchcans so i wanted to do that 3rd se tup on calan's thread. which is deleting the pcv with a barb fitting then run that to the can, the other breather port to the can then get the vacuum source from intake pipe

 

[rEclipserGST]

You do not need to delete the PCV unless this is a racecar. So get that out of your head.

I was just telling you I run TWO CANS. You don't have to. But you do need to add a check valve if you want to maximize the efficiency of your setup. Even WITHOUT cans, a check valve is great to add inline.

 

[Allen2g]

Do you not delete the pcv valve for this setup with one can.

 

[ThunderChild]

Do you not delete the pcv valve for this setup with one can.

You keep the stock pcv valve and line to the intake, you're just adding a catch can between the fresh air intake and VC port for more flow. I'd venture to say the setup you showed would be better for a larger turbo moving a larger volume of air.

I personally run 2 sealed cans, with stock pcv valve and a check valve. This is my setup:

You must be logged in to view this image or video.

 

[99gst_racer]

Do you not delete the pcv valve for this setup with one can.

Actually, no. Craig calls it a Positive Crankcase Ventilation setup because it uses pre-turbo intake pipe vacuum to draw on the crankcase, but it does NOT use the OE PCV valve in that configuration. And the reason is that the OE PCV vale would never open and would essentially act as a plug in the line.

 

[rEclipserGST]

You keep the stock pcv valve and line to the intake, you're just adding a catch can between the fresh air intake and VC port for more flow. I'd venture to say the setup you showed would be better for a larger turbo moving a larger volume of air.

I personally run 2 sealed cans, with stock pcv valve and a check valve. This is my setup:

You must be logged in to view this image or video.

Same setup I am running.

 

[ThunderChild]

Actually, no. Craig calls it a Positive Crankcase Ventilation setup because it uses pre-turbo intake pipe vacuum to draw on the crankcase, but it does NOT use the OE PCV valve in that configuration. And the reason is that the OE PCV vale would never open and would essentially act as a plug in the line.

Correct for the pic he posted from Calans thread, you would delete it of you're only going to run the dual line, single can to the turbo inlet.
I just assumed OP would be keeping the pcv to IM line, and hence the pcv valve itself, since it will be a street car.

 

[Allen2g]

Correct for the pic he posted from Calans thread, you would delete it of you're only going to run the dual line, single can to the turbo inlet.
I just assumed OP would be keeping the pcv to IM line, and hence the pcv valve itself, since it will be a street car.

Yesss thats what im talking about . Delete pcv with a barb, then run that towards the can, the other port to the can then get the vacuum from the intake pipe. What im wanting to know is whether itd be okay to run that setup for a daily driven 2g gst.
I really like that setup as its a single can and super simple

 

[ThunderChild]

Personally I'd at least leave the stock pcv in place and run the can on the fresh-air side, since a DD will see alot more vacuum scenarios. That's why I retained mine, it's a street car that sees the strip a few times a year, and I get a bit of oil in both my cans, more on the fresh-air side tho since I have my foot buried most of the time...

But yes, you could delete the pcv and run the single can on the fresh air side, just not what I'd recommend for a street/strip.

 

[Allen2g]

Personally I'd at least leave the stock pcv in place and run the can on the fresh-air side, since a DD will see alot more vacuum scenarios. That's why I retained mine, it's a street car that sees the strip a few times a year, and I get a bit of oil in both my cans, more on the fresh-air side tho since I have my foot buried most of the time...

But yes, you could delete the pcv and run the single can on the fresh air side, just not what I'd recommend for a street/strip.

Thank you! Made it clear aha

 

[slowwhite]

Its currently being suggested that I am having a high crank case pressure issue. My car came with a vta dual -10an off the VC catch can. which id like to switch to a sealed setup.

The radium engineering catch cans have caught my eye. Has anyone ever used them or recommend using them?
Should I go with single or dual cans?
http://www.radiumauto.com/Universal-Competition-Catch-Can-P289.aspx (for reference)

Or Calan's V3 can (thought I read he was working on a road race specific can but hadn't seen if it ever panned out)

Or would just welding a bung where the vta filter went on my current can and route a line from there to my fp intake pipe?

My car is street driven but will see road race use hopefully often once I get this issue sorted out.

 

[rEclipserGST]

Its currently being suggested that I am having a high crank case pressure issue. My car came with a vta dual -10an off the VC catch can. which id like to switch to a sealed setup.

The radium engineering catch cans have caught my eye. Has anyone ever used them or recommend using them?
Should I go with single or dual cans?
http://www.radiumauto.com/Universal-Competition-Catch-Can-P289.aspx (for reference)

Or Calan's V3 can (thought I read he was working on a road race specific can but hadn't seen if it ever panned out)

Or would just welding a bung where the vta filter went on my current can and route a line from there to my fp intake pipe?

My car is street driven but will see road race use hopefully often once I get this issue sorted out.

That is a nice looking can. I like the velocity graph they added. My ebay can is about half the size of that. Using the same type of filler as well. And a lot cheaper.

 

[EVLGSX]

Ive done a ton of reading on this and havent found why if SD, you shouldn't just run 2 lines to 1 atmosphere vented can. No PVC valve at the cover.

Is there a reason? On SD just to be clear. No MAF.

 

[ThunderChild]

Yesss thats what im talking about . Delete pcv with a barb, then run that towards the can, the other port to the can then get the vacuum from the intake pipe. What im wanting to know is whether itd be okay to run that setup for a daily driven 2g gst.
I really like that setup as its a single can and super simple

Ive done a ton of reading on this and havent found why if SD, you shouldn't just run 2 lines to 1 atmosphere vented can. No PVC valve at the cover.

Is there a reason? On SD just to be clear. No MAF.

I guess I don't see how being SD would have any bearing on the catch can setup, but I'll bite.

Essentially, since SD system only looks at baro and iat, the catch can could somehow cause a pressure differential and throw things off. I highly doubt this though.

Catch cans should be more thought of in a "what am I doing with the car" fashion. Just because you have two massive lines to a vented can that looks pretty, doesn't mean it's right for you're car.

2 sealed cans seems like a reasonable choice for 90% of us running street/strip.

Once you start pushing higher crank case pressures, spending less time idling or DDing the car than you do with you're foot mashed to the floor, is when you might consider moving to a high flow can, capable of at least relieving pressure to near ambient levels.

Also, most race cars aren't even running an intake pipe on the turbo so you cant run a fresh air suction line to the can, and I'd bet ppl running 50+ psi aren't wanting to have a possible leak from a pcv line/valve self destructing or popping off at said pressure in the middle of a race.

The idea is to pull a vacuum on the crank case, which a stock like system is barely able to do, but better than a single, huge lined vented can.
Race cars should be running a vacuum pump of sorts to actually pull vacuum on the crank case from a proper ventilation and power production stand point. Sadly they're complicated, costly, and steal power from the engine/electrical system, as well as take up space and add weight.

Vented catch cans are more cost effective and at least keep things manageable for race teams. For daily cars, one or two sealed cans are better options. I also don't see how SD or MAF plays into it aside from my above mentioned thoughts.

 

[EVLGSX]

If you ran a vented setup like I described with a MAF you would have a huge un-metered air issue.

Crankcase vapors promote detonation.

I just wasnt sure if there was a downside to this preassure relief setup.

 

[slowwhite]

This is a bit off topic. But has anyone combined a sealed can along with the stm -6an dipstick routed to the catch can as another way to help remove crank case pressure?
Or what are people's thoughts on this?

 

[ThunderChild]

If you ran a vented setup like I described with a MAF you would have a huge un-metered air issue.

Crankcase vapors promote detonation.

I just wasnt sure if there was a downside to this preassure relief setup.

I guess I didn't quite get that out of your other post, but yes you're correct on both counts. Once again, in daily driver I don't see it being as big of an issue (detonation from CCG) as on a race car, on which i definitely wouldn't want things going through my intake tract.

As far as pulling from the dipstick, yes you could do that in addition (I wouldn't use it as a sole draw point) to another vent, but I think you'd be more likely to suck up oil since its proximity to the sump is quite close.

I was always a fan of tapping the rear balance shaft/oil pump shaft hump and running a line off there, since it would promote oil drain back through the head drains as well as relieve CCP. Add a vacuum relief valve on the valve cover with a small foam filter over it and you could regulate the amount of vacuum the crank case sees, promote oil drain back and clean things up engine-bay-wise all in one shot. Obviously a vacuum pump or dry sump would be the only way to go for that style.

 

[curt-s]

Ive done a ton of reading on this and havent found why if SD, you shouldn't just run 2 lines to 1 atmosphere vented can. No PVC valve at the cover.

Is there a reason? On SD just to be clear. No MAF.

if you plug the intake manifold barb and only run those two lines off the valve cover, there is no metering issue or SD VE problem.


i have been running two lines off the VC and then two to the preturbo intake through a custom baffled ebay can. works great based on amount of oil is in can and not sitting in compressor housing.
however, how much vacuum is actually being drawn by the can, even at 160k rpm on a b16g? i might do some metering this year.

most blowby and crank vapour churn happens on boost but a higher vac source pulling at idle and cruise would be nice, thus a two can setup as described earlier. although, the vac loss from the check valve may reduce overall gains.

 

[EVLGSX]

Of coarse no metering issues if SD. That was never in question.

Metering issues would only be if using MAF

The main benefit of the two line 1 atmosphere can, from my understanding, is no crankcase vapors being sent back through your charge....... so if your on the ragged edge, in send mode, with something like a 16g, this could help raise the knock threshold?.......along with anything else you can do............... Correct me if Im wrong.

I just dont know if there are downsides to this setup for a street/strip car. Anyone?

 

[ThunderChild]

Aside from not evacuating CCP in normal driving as well as a stock setup or single/dual sealed can could and when NOT in full send mode, should work fine technically.
Just have to wonder where your fractions of power are being left on the table. Save some knock range, but lose some power to more CCP. We're talking fairly small power amounts on a street/strip car or daily, but it's all up to you're driving style and what you do with the car.