DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Double Catch-can setup?

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Old 05-07-2007, 04:59 PM
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Default Double Catch-can setup?

Hi,
I am finally putting all the damn things togheter!!

I have removed the egr, cleaned the intake manifold so good that it shines, so I don't want oil and dirty in it anymore.

What do you think of a double catch-can setup?
- the first catch-can will be on the breather side of the valve cover, beetwen the breether port and the turbo inlet (after the afm);
- the second one on the pcv side of the cover, beetwen the manifold and the pcv port on the valve cover.

I want to mantein the pcv working, so I plan to move the valve (already bought the 323gtx one) beetwen the manifold and the catch can, so that the can doesn't see boost.

Does it sound good? Is it the best setup possible??
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Old 05-07-2007, 05:13 PM
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why not just have 2 lines going into 1 catch can?
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Old 05-07-2007, 05:28 PM
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I tought the same, then I read this:

From: http://www.saikoumichi.com/DC3_page.htm

"So, why 2 catch can? Why not join the breather and the PCV line into 1 can?

The simplest way to explain it is this... The PCV system works in ONE direction. Under vacuum the flow comes from the valve cover through the PCV valve and into the intake manifold, during this time, the air that is being sucked out is being replaced by the air coming in through the breather hose. Air comes in, and air goes out through the PCV line. When 2 lines go into 1 can, there is NO VACUUM effect possible.

So, why does the breather need a can if the flow only goes in one direction?

Under normal conditions this may be true...but under extreme boost, the breather line may experience a strong vacuum effect and actually cause the PCV valve to leak, allowing oil vapor to be sucked into the turbine and the intercooler which reduces it's efficiency."
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Old 05-07-2007, 07:08 PM
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yeah, putting both into one can effectively removes all the vacuum from the crankcase in boost.

sounds like a plan jhoexp. The hardest part will just be finding space.
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Old 05-07-2007, 08:05 PM
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Ok, I will start my project.

Read somewhere that to be effective the catch-can should be baffled internally to separate the inlet from outlet and filled with some sort of stainless mesh to help condensation.
Don't have time to go around to find the bits to do one myself, so I think I'll buy 2 from ebay and modify it with something that I already have...

Do I really have to sacrifice a PCV valve using it as an adapter to hook the hoose to the valve cover hole?

If the catch tank sees boost (say...max 12 psi), will it blow up?:gay:
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Old 05-07-2007, 08:10 PM
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shouldn't....I pressurized my to like 30psi...($20 ebay one)
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Old 05-07-2007, 08:45 PM
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Bought 2 of this:
http://cgi.ebay.com/ebaymotors/ws/eB...m=270117143510

Not the cheapest one, but has the lower shipping to italy. (still a theft, anyway...)
Hope i'll find a place to fit them...
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Old 05-07-2007, 08:50 PM
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"steal"
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Old 05-07-2007, 09:00 PM
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Originally Posted by Braineack
"steal"
Ehm, sorry :gay: ... sounded similar to me. (love this smile)

I am not just learning how to turboing a miata...I am learning your language too!
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Old 05-08-2007, 12:40 AM
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Chanting *One of us, One of Us, One of Us*
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