I get what you are saying. Basically you are stating that air enters the crank case via the hose that on a stock car runs from the intake tube to the valve cover and then exits the crank case via the PCV valve and on into the intake manifold. You are also saying that by running your hose to the ground as VTA (same as a breather filter would do on your valve cover) that you will not get the full potential for vacuum as you will only be sucking air from the atmosphere and relying soley on the vaccum from the combustion chamber to draw air. By taking air from the intake tube you have the added vacuum of the turbo drawing in air. That would also be the sound you hear from any intake, turbo or NA. Sucking in air that is (vacuum). As an added bonus, that same air is metered, as you said, so you will not have any sort of AFR problems as the MAF read that air already.

I totally agree and actually plan to a DC3 or similar can and tig a nipple onto a Buschur intake this summer when I run new UICP. All I was saying is what was told to me. I was also saying that many people run breathers with no problems and running a hose would work just as well as a breather but def not as well as sourcing air from the intake.

In the end, as I stated weeks ago, the Mitsu engineers have things plumbed the way they do for a reason so if in doubt as to believe some tuner or the way the car sits stock, go with the latter unless you can thoroughly explain why your way is better.

PS: I was not getting upset at all. I like to talk and think about things rather than just repeat what I was told or read as many do.

 

Blowing out your dipstick is a problem and putting a spring on your dipstick doesn't fix the problem. So we see, in fact, people do have problems with running an open breather. I also had problems on my Z with an open breather until I took some advice from a good buddy who had designed a simple PCV system. I still don't know why people switch from the stock setup to an open breather system. Perhaps someone can post some information to add clarity to this issue.

 

Well I never blew out my dipstick but then I still run the stock intake tube and hose to my valve cover with my APS intake. I think the reason Buschur and some other companies do not have a nipple on their intake is so that you do not have to run a catch can and wont get blow by in your turbo/FMIC, etc. I personally plan to switch to a Buschur intake only so that I can run a shorter UICP and reinstall my stock reservoir making it easy to run meth/alky in the future when I am ready for that mod. But again, I plan to run the DC3 or build my own can and weld a nipple onto the BR intake so that I can run the double can set up in series with the other PCV components for all the reasons we discussed. I think we are, and have been the whole time, on the same page. As for the dipstick thing, well that is something I forgot that people have problems with. I never really paid much attention since I dont have that problem but it makes sense that the pressure would cause this. Or at least it seems possible.

I just wonder if anyone else is reading this and thinking about it or just not giving a rat's a$$.

 

Who knows? I would be interested in seeing what you come up with when it is done.

 

Well here is something else I thought of. How would a breather or hose off of the valve cover cause higher crank case pressure? Well, more so than stock. See I was thinking and when the dip sticks blow the car is under full boost right? But when the car is under full boost nothing comes out of the PCV into the intake manifold right? Well it that is true then no air would be sucked from either the stock intake or a breather or hose or anywhere when the dip sticks blow. The only advantage then to hook up to the intake tube at all would be sourcing metered air. But as most say, that slight bit of unmetered air does not cause driveablitly issues.

Please correct me if I am wrong on any of this. I am just trying to think about this and educate myself and maybe others.

 

Supposedly the sourced air coming from the intake (vaccume) provides assistance in getting the fumes/oil to circulate better out of the valvecover/pcv valve...

I dont think that the pcv valve only pops out under boost either...as the pcv valve is closed during boost...

 

^^Yes, that is exactly what I said.

 

With an open breather you can never hope to achieve anything better than atmospheric pressure within the block. However, we know that some people are blowing out the dipstick, which means the block is experiencing positive pressure. If we compare this with the stock setup that hooks to the turbo inlet(vacuum source) we have the potential for lower block pressures because of the greater delta Pressure.

With the tube running to the ground and the other on the PCV, when the car is under boost the PCV is shut and block pressure is forced out of the open tube. If you hooked that tube to the turbo inlet(vacuum source) you would have the benefit of an additional Pressure delta as compared to venting to atmosphere. As I stated with the TTZR1, the catch can was reading ~3in-mg at 7.5psi of boost. This is a closed system so I suspect the block is being completely evacuated and there is no positive pressure.

 

I may order a nipple to add to my turbo inlet tube and then use my DEFI boost gauge to measure the vacuum under full boost.

 

So basically you as saying this. Correct if I am wrong.

Under boost the crank case is ventilated by the intake tube as a vacuum source.

Under vacuum the crank case is ventilated by the PCV valve / intake manifold as a vacuum source.

This makes sense and would explain why there is blow by in the intake. According to some threads and the DC3 website, it basically says the hose from the intake to the valve cover only acts as a way to source air to ventilate the crank case out the PCV. But if it is also in fact a way to ventilate out while under boost while the PCV is not functional then this makes sense but is news to me.

I agree that the car would only see 14.7psi or 101.3kPa or whatever atomposphic pressure is (I think I remember correctly there) but I thought it would only ever see that anyway. But I was only thinking that because the intake tube is VTA via the air filter. I didnt think about the air being sucked in. That would cause vacuum. Actually, just air running over the opening of the hose (from the valve cover) alone would cause vacuum. It would work just like a Pito tube. The turbo would just increase this flow and vaccum.

 

Also, I am getting that same nipple there from ATP. I am going to put it in the coupler between my LICP and FMIC to source boost instead of the BOV line like now. Off topic a bit, but that is a neat little device.

I would be interested to see your vacuum data from your intake tube if you do this. <==That is on topic

 

What vcv fitting are people using that have intakes which do not have the vcv nipple on their intake?

I am looking at drilling and tapping the intake with a 1/4 NPT x 5/16 barb, but I dont want the restriction of the extra threads in the intake tube....unless it dosent matter..

 

^I doubt it matters but I thought of this too. Also, consider how thin the intake tube material is. Do you really think you can drill and tap that? Bring it up here and my buddy Ben from work will weld a nipple on for you if you buy the SS stick. He is a TIG masta!

 

well I drilled and tapped the UICP no problem.....shoot me a pm and I will make the trip up there to get the fitting welded on. Is there a certain type of material i should get the fitting in? IE, brass, SS?

 

How bad for the turbo is it to allow this oil to run into it?

I pulled off that intake hose the other day to change out my radiator and found black oil in my turbo.

Cars runs fine but this can't be good? I am going to need one of these catch cans to solve that issue.

WADAD