Where do these vacuum lines go?

[pumpiniron]

Finishing up my RB20DET swap in my S13... There is a few vacuum lines that are missing the hose and I am wondering where they go... I was hoping if I took some pictures some of you all might be able to help so here goes nothing...

These two vacuum ports right on the intake manifold...

[pumpiniron]

This vacuum line coming from underneath the throttle body...

[pumpiniron]

This line is coming from the underside of the stock turbo (the line says TRUST on it so I'm assuming the previous owner had some sort of boost controller or something hooked up)

[pumpiniron]

This vacuum port is on the back of the intake manifold I believe...

[skillzilla]

The first two connect to the Intake pipe that runs across the top of the motor. The big one connects on the rear side, towards the firewall, small one connects to one of the hardlines that are attached under the pipe.

The third one is for the wastegate actuator. It looks like the previous owner had an aftermarket boost controller on there. To revert it back to stock, just run that onto the nipple on the actuator (brass drum looking thing on the turbo). That will give you stock boost levels.

Fourth one is most likely where the previous owner had a boost gauge hooked up. If you are using an aftermarket boost gauge, hook the vacuum source to here. If not, find a bolt that fits in there or cut a small piece of hose, put it on the nipple and clamp the end shut. This is just a true vaccum source, and isnt needed for anything.

Thats about it, good luck with the swap.

edit: 420th post, w00t!!!

[pumpiniron]

Thanks, you answered all my questions perfectly! My swap didn't include the intake pipe that goes across the top of the valve cover... Guess I better try and find one ASAP!

[Gold Digger]

Ok...I have some pics for you just to make sure you know where each part goes. I have this fresh in my mide due to the fact I had to redo my lines on my Laurel. The Laurel and the Skyline RB20DET's have many subtle little differences that I didn't know. So, I will fill you in on what you need for a Skyline RB20DET.

First up...your pic with vacum ports numbered.

This pic, the big line, number 1 goes here...right before the coupling to the throttle body.

This one, numbers two and three. I don't have a number three because the C33 Laurels didn't come with a BOV (recirc valve) Mine has one because the previous owner put a Skyline cross pipe and had to rig the vacum lines to support the BOV.This is how it should look.This is where numbers 2 and 3 go to. You will see there are three steel tube lines. The lines will have mounting tabs to bolt to the intake cross pipe. At the throttle coupling, there are three lines. One goes from the number 3 port to the BOV line. 2 and 4 go from their locations to the charcoal filter box. (I think that's what that thingy is.) This picture is taken at just before the curve in the cross pipe from the cold side of the intercooler.

And here is what my RB has where you have a fitting.

I am also including a MS Paint diagram of the three steel tube lines I mentioned before. Make sure if you get that cross pipe, you get these lines. I plan on going back to a stock BOV, but I need to route a fitting into my intake tube to the turbo so I can recirc, because, as I said before, the C33 Laurel didn't have a stock BOV and the stocker vents to much at idle to allow my engine to idle correctly.

Hope this helps you out a little more.

-Neal

[pumpiniron]

Good god man, that was by far the most helpful thing you could have ever done for me. That totally answered every question I had, thanks for the diagrams and everything to. Now I'm very clear on things. I guess I will have to be sure to locate those lines when I pick up a stock intake pipe... I think that fitting that you have blocked off on the back of your intake manifold has an aftermarket plug in it on mine because I'm almost 100% sure the previous owner of this motor had a boost gauge hooked up to it. So how about these people who aren't running the stock intake pipe... Are you having your custom pipes made with all these vaccum line plug ins or can you just cap off the vacuum lines if you go with an aftermarket setup?

[pumpiniron]

Oh by the way... Where is the charcoal filter box? I am not sure if my motorset came with one or not and if it didn't I'm assuming I'll have to locate one? Probably not good to run the motor without one? Got a picture of the charcoal filter box perhaps so I know exactly where my 2 and 4 lines are going...

[Gold Digger]

I can't remember if USDM cars have them...I think they do...but it's that round cansiter that has a little cap on the top. Mine is up by the radiator right behind the left headlamp, up by my air fliter.

Glad you liked the pics and stuff. Just be sure, if you need any help, let me know, I'll see what I can do. I'll even keep my eyes open for the lines for ya too.

[pumpiniron]

Oh the charcoal canister, yes my car has one, I know what you're talking about... Can I remove that thing or is it actually needed to make the car run right? Seems like it's hoakey and taking up room to me.

[Gold Digger]

Oh the charcoal canister, yes my car has one, I know what you're talking about... Can I remove that thing or is it actually needed to make the car run right? Seems like it's hoakey and taking up room to me.

Well considering one of the vacum lines runs to it, I don't know how it would act if you didn't run them.

[skillzilla]

It isnt needed, just a part of the emissions sytem. However, if you get an underhood visual inspection for an emissions test they will look for it, so be prepared. If you dont want to keep it, just block off the vacuum line that runs to it. I put about a 1.5" piece of hose on the end of the hardline, screwed an apprpiately sized screw into it, and put a ziptie on that. It is under the intake pipe so you cantsee it unless you look.