Can we get an official 'Catch Can' Thread?

[87M-GTE]

I've spent the last hour and a half searching and researching this topic and have come up with about two or three preferable options, which I will picture below.

I found at least 6 recent threads all relative to this topic and they all are different, suggesting different ways of installing and routing their PVC systems. This obviously is a very controversal topic, which it truthfully should not be. I think we should attempt to set the record straight.
There is apparently more than one way of doing this right. Lets set aside all ego's and "a buddy had..." I want personal exeprience with success.

Obviously there are different types of setups, and lets try to establish a "stock-ish" kindof PVC upgrade, No ffim, etc.

In my research I found a few pictures of setups that I personally think look to be successful by the desriptions in the original thread they came from, which I will post links to at the bottom in same order of pics.
none of these are my cars. If they are yours, or not feel free to coment on them. All I am trying to do is establish a good, easy, and understandable method of installing a catch can, to be efficient and more over do its job.









http://www.supramania.com/forums/showthread.php?t=100322

http://www.supramania.com/forums/showthread.php?t=72991&page=2

http://www.supramania.com/forums/showthread.php?t=43167&highlight=Catch

Thanks for looking, lets try to work together to make the community a better place.

-Sam

 

[dumbo]

I smell a much needed sticky...feel free to delete this.

 

[jdub]

I've spent the last hour and a half searching and researching this topic and have come up with about two or three preferable options, which I will picture below.

I found at least 6 recent threads all relative to this topic and they all are different, suggesting different ways of installing and routing their PVC systems. This obviously is a very controversal topic, which it truthfully should not be. I think we should attempt to set the record straight. There is apparently more than one way of doing this right. Lets set aside all ego's and "a buddy had..." I want personal exeprience with success.

Obviously there are different types of setups, and lets try to establish a "stock-ish" kindof PVC upgrade, No ffim, etc.

In my research I found a few pictures of setups that I personally think look to be successful by the desriptions in the original thread they came from, which I will post links to at the bottom in same order of pics.

none of these are my cars. If they are yours, or not feel free to coment on them. All I am trying to do is establish a good, easy, and understandable method of installing a catch can, to be efficient and more over do its job.

View attachment 29970
View attachment 29971
View attachment 29972
View attachment 29973

http://www.supramania.com/forums/showthread.php?t=100322

http://www.supramania.com/forums/showthread.php?t=72991&page=2

http://www.supramania.com/forums/showthread.php?t=43167&highlight=Catch

Thanks for looking, lets try to work together to make the community a better place.

-Sam

The reason you get so many "opinions" is guys seem to route the PCV system on the fly...basically whatever looks good or offers the most convenient hose routing. The problem is these same people don't know how the PCV works on the 7M...kinda surprising since it's such a simple system.

A few facts on how the stock 7M PCV works:
- The engine requires vacuum to effectively remove combustion byproducts from the crank case/oil...primarily water vapor.
- The primary vac source is the TB port...it is an orifice designed to provide max vacuum and limit back flow from boost.
- The accordion hose provides near zero vacuum...it is actually a return path for boost back pressure on the turbo motor.
- Under boost, the flow from the TB port to the accordion hose produces a venturi effect across the cam cover ports, assisting flow to the accordion hose.
The same thing happens under manifold vacuum, but pulls crank case vapor to the TB...it is much more effective.
- Flow depends on the path of least resistance...the 7M PCV system is an elegant design in that respect.
- The PCV is a closed system. The design keeps metered air in a circuit eliminating any adjustments by the TCCS.

When installing a catch can, you want to mimic the stock system as close as possible...in reality, there is ONE WAY to install a catch can and route the hoses correctly. Pic #1 above is the best set-up and will work as depicted. Personally, I would install a check valve (PCV valve) between the "T" and the accordion hose that will only allow flow toward the accordion hose. This will allow max vacuum to be exerted on the catch can (shown as a compressor filter in the diagram)...it will not inhibit back flow under boost, thus avoiding catch can pressurization.

On the NA motor, the path to the accordion hose (or intake) is not required...there is no boost to consider. Here's the TSRM depiction for both:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=EC&P=5

Sticky...meh. If guys would just stop and think about this for a minute and reference the TSRM vs routing hoses helter skelter, there would be far less "opinion" on this subject. It's funny how when people do something, pride takes over and the brain cuts off

 

[tekdeus]

Jdub, any idea why Toyota opted to pull such a very weak vacuum on the crankcase, instead of having a PCV valve create a strong vacuum like you mentioned?

 

[jdub]

Boost also tends to pressurize the crankcase to a certain degree...since flow will take the path of least resistance and with crankcase pressure assisting, the stock system is adequate. Putting a PCV valve in the location I mention will help though...if you are going to install a catch can, might as well do a small upgrade.

Note that the NA motor puts full vac on the cam cover ports via the same type orifice.

 

[Enraged]

what if you have an aftermarket throttle body (BBK for a mustang in my case)? Should I still plumb a line to the catch can as jdub posted? Pre or post throttle plate?

 

[jdub]

Plumb it after the TB plate...you will need an additional PCV valve in the line connecting to the intake manifold that allows flow only in the direction to the manifold. Otherwise you will have a boost leak.

 

[theKnifeArtist]

I just sold the catch can in my car. fuck it, nice simple redone oem setup for me

 

[QWIKSTRIKE]

My car domain page shows the proper way to set up the PCV, and you can see the check valve inserted in between the stock hard pipe and vaccum hose. You will also see 2 catch cans in my setup. One goes to the intake off of the turbo for optimum efficiency, and the other is in between the FFI intake, and the hard pipe off of the valve covers. This setup was personally confirmed to be the best route to me by the great Dean Marcum! Since I thought it was an origiinal idea he told me he had his setup this way years ago. I guess great minds think alike.

http://www.cardomain.com/ride/571789/19