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OK folks, routing my vac lines and have a question.

I've got my vac mani installed, no worries there.

Question 1: But what I'm curious is that on there is a vac port on the intake side of the turbo itself. This just needs a normal vac source right?

Question 2: Next question. MBC goes in between the WG and the vac mani. So does my boost gauge go in between the controller and the WG or just off the vac mani?

I would think in between the controller and the WG so I know how much boost my WG thinks its seeing, right?


Question 3: Last question on the catch can. I know you've explained this to me before Justin, but let me make sure I understand. Take it from PCV -> catch can -> intake mani, right? Like I've done in this diagram here?


Here's what I'm talking about.

MBC to boost gauge relationship #1 (I think this is right)




Or MBC to boost gauge relationship number #2

 
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I'll check this again in a half hour, before I run to town to pick up my buddy's Jeep. Gotta do some work on it while he's deployed.

News Team!!! Assemble!!! <Blows on conch shell>

 
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The turbo doesnt need a vac source. You need a post turbo vacuum source. The vac mani will work, but if you're using a MBC, make sure it can tolerate post throttle vacuum. Otherwise you're gonna want to put a tap in the charge pipes or turbo compressor housing.
the boost gauge taps into the IM (the vac block is fine)
PCV rig is wrong. Either vent it to the atmosphere, or put a slash cut tap in before the turbo (in the filter pipe). If you dont have a well baffled can, vent it to the atmosphere.

 
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Then what is this nipple for on the turbo? Could it be a feed to the wastegate, right at the boost source so the control may work a little quicker than if the signal was taken from the manifold?



OK, I understand the boost gauge bit now. The gauge will be accurate because when the WG bleeds off exhaust that vacuum pressure will be constant throughout the system. I won't have two different readings, one before and one after the MBC.

I'm using the Voodoo IV HP controller so it should be fine.

 
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I think I've got it now. Good thing I didn't go cutting hoses until after your post got edited about the PCV. Looking at homemade turbo.com, it shows this setup for a turbo with a pressure nipple on the turbo.





Since the manifold pressure under boost will be constant throughout the system, as its regulated by the MBC and WG, this seems to make sense. Turbo pushes air feeds at essentially two pressure sources - 1 directly on the turbo housing and the other by proxy on the intake manifold, which the vac manifold is tapped off of. Since you want the shortest length of line between the WG and the turbo, it makes sense that they put the nipple on the housing.

This makes sense, right?

Which in turn would make the wire diagram look like this. (Updated with correct PCV-catch can routing.)

 
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In case I didn't say it, I definitely appreciate the advice. This is embarrassing as I should have figured this out before starting the install. Lots to learn when you're doing this for the first time. Thanks!


OK, brought the laptop into the garage (yay wireless!). I changed my diagram after initially posting it (post is edited) to how I'm going to do it. Since I initially had the catch can incorrectly plumbed back in to the intake mani, that part of the diagram is still wrong. Let me fix it real quick.


There. Done.

This should be better and should also be the final correct version of the routing. Now to cut open my Ebay catch can and add some baffles and stuffin'!

 
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^^ would that be a correct diagram for most turbo setups??

 
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Only if they have a pressure source on the turbo housing. I'll clean up and post both versions, one w/turbo pres. source and one without - as long as the smart turbo folks agree this is correct - and ask the mods to sticky it in the this section.

Almost done modding my catch can.....

 
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cool beans...just saving all this stuff along the way. in case i ever do a turbo build years from now..

 
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Good to go man. Catch can is now modified. Check my build thread to see how I did it. Its neato.

 
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read the tial instructions. IIRC, with the twin port WG, one gets hooked up to the turbo and is boost only, the other side goes into a vacuum line and is boost and vacuum. I'm not sure, internal gates are easy.

 
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Yeah, I read them and it says that top one is an atmospheric vent - which would mean boost if I'm thinking straight (its late now - midnight - and the boys have been drinkin'). It shows the line routing like we have it in that final diagram. I almost went with an internally gated snail, almost wish I had.