Yes, boost pressure seen at the valve cover is the same... but without the vacuum, crankcase boost pressure is now seen all the time instead of only under boost.

Is it enough of a difference to create a problem with long-term reliability? Probably not.
But it's enough of a question for me to spend the rather low $100-200 for a 2nd can instead of rolling the dice on my car.

-------

Another point that should probably be brought up is, with the boost tap & single catch can (or similar) method, one failure in the catch can installation can cause serious problems.

For example, the hoses on my catch can install were collapsing on me, restricting flow. It wasn't too bad because there was still the 2nd vent path for the crankcase, but without that (and if I didn't notice it first), it could've led rather quickly to a serious crankcase pressurization issue and possible blown gaskets.

And a MINI service technician was telling me a month or so ago about one guy who came in with blown gaskets due to a catch can (that I've seen other NAM people talk about installing in their R56s) restricting flow because it had much smaller diameter ports on it than the stock hose diameter.

Two vent paths at the very least provides a safety net against such cases where something doesn't behave as expected.

 

I've been running with the BSH boost tap plugged for 23K now with no problems or leaks anywhere. I'm using the 42 DD can and hoses and the hoses are still firm and not collapsing.

 

If you're using the boost tap, then your hoses are on the line to the CAI, not the vacuum line to the intake manifold. That's where I was seeing them collapse.

 

Quick question: Is the Dual Boost Port easy to put on and take off? Does it look like it's manufactured to survive that kind of stress? I autocross and the class I'm in prohibits any modification of the PCV, so I can't run with it on. But I have the OCC and when I'm just street driving I want to make the most of the OCC by shutting off the PCV side. Basically, I'd have to take it off before events and put it back on afterwards. Does it seem like this would be feasible, or a complete PIA?

 

If you de-burr the inside edge of the PCV nipple/port that you're pushing the dual boost port into (to prevent tearing/damaging the O-Rings on the part), you might be able to swap it in and out before & after autocross events. If you need to install and remove this part a lot, I'd recommend having spare o-rings on hand.

-Clint

 

Clint, for de-burring what would you recommend? Also I suppose no lubricant of any sort to easy the Boots Tap port in?

 

Lubricant may help to ease the boost tap install, there are a few O-ring lubricant products out there for camera equipment that come in small tubes and will fit the bill for a one time installation.

http://www.adorama.com/IK5020.html?u...m_source=gbase


I'd recommend getting a larger tube if you're constantly swapping this part.
http://www.impactcomputers.com/68201-19-4.html#

As for the deburring, something like this (or similar) will work.

http://www.amazon.com/Fowler-52-483-.../dp/B002YK93S4
A deburring tool like this one can be purchased at just about any hardware store or home center.

This item also seems like it could work for deburring.

http://www.build.com/ridgid-35155-mo...LAID=580843753

Best,

-Clint

 

Does anyone know what size the hose is that comes with the BSH OCC?
I want to go buy some hose clamps and want to make sure I get the right size... is that about 3/4" hose?
Do i need clamps for the intake and valve hose connections? Or just for the connections into the OCC?

 

I didn't use any clamps on the hoses to the Oil Catch Can. There isn't any pressure on those hoses, there's actually a slight vacuum. They fit pretty tight anyway.

Dave

 

ok, i guess i'll see how it goes during install. I suppose some people put clamps for piece of mind?

 

+1 Its just slight vacuum, you dont need a heavy duty clamp or anything like that, The factory pcv isnt even on tight its self.

 

I just used ty-wraps.

 

I'd use clamps (as opposed to nothing) just to be sure oil won't leak out over time.

 

Its under vacuum, technically that will prevent "leaks" alone.

 

deleted

 

Usually per oil change for me, I emptied it after 5k this past go around and it was 3/4 of the way full, As long as it is not up to the hoses you should be good, i also installed mine in a different location tilted a little backwards so theres no chance of liquid passing through the hoses.

 

i just received my BSH OCC and Dual boost tap! They both appear to be high quality.

Quick question about the dual boost tap. I need to put in all the pipe plugs for use with the occ and no boost gauge? There are 2 small plugs on the sides and 1 large plug for inside? Do I have it correct?

 

Yes, you are correct. If you know you won't be using the ports for a boost gauge, use high temp loctite to seal the plugs in place. Happy motoring....

 

Yup

 

You insert plugs into all the holes if you're:
A) not running a boost gauge or another pressure-based device/sensor, -and-
B) want to block one side of the PCV plumbing with the large plug to make the catch can grab more gunk.

-Clint

 

I may be wrong, but I don't think there is a high temp Loctite. Usually you use heat if you need to, to release Loctite products.
I would recommend a tiny bit of teflon pipe paste unless you want to try and wrap the tiny plugs and big plug with teflon tape. Good luck.

 

thanks all for the quick replies!
I am going to get some teflon pipe compound and hose clamps today. Hopefully i'll get the install done tomorrow or wed.

 

Yet the neck of the "in" port on my catch can has a coating of oil on its exterior up to right around where the clamp sits. Not sure if the clamp is keeping it from seeping or not, but the oil seems to want to go that way (my guess is that small quantities of oil are pooling where the hose meets the mouth of the "in" port, and capillary action is pulling it down that crack between the hose and the exterior surface of the port... but that's just a guess).

 

If its blocked there is no airflow going through there so theres nothing to worry about. You have 2 cans though correct?

 

No Fishbert only has a can on the Throttle Body side and no can on the turbo side for now.