vacume questions

[bustedasska-t]

Ok so welcome to my post I'm a long time reader and FIRST time poster. So on to my issues so I'm working on my s13 and I'm in the processof boosting it. I have done a vacume delete and only have the vacume line going from the fuel pressure regulator to the intake, brake booster and whatever that line that comes out right next to the tb. I need to run my boost gauge wastegate bov and manual boost controller the kind with 2 pegs. my question is where I should pull vacume from I have the port on the bottom of the tb plugged but I can un block it easily enough I keep hearing conflicting things like the tb is unreliable and such is it bs? Or should I t off the fuel regulator line? Another thing I heard is that the best way to mount the maf is down stream of the bov but I couldn't get a good reason why. How do I hookup the external wastegates vacume lines, I read that the vacume line runs into the side and the top is for a electronic boost controller but everything iv read just says leave exposed and that seams like a bad idea so should I put the fitting in and just leave it with no hose or should I put a hose on it and recirculate it somehow or what!!! Where does the boost controler go in front of? Well thanks in advance

[compactfean]

You are correct, the vacuum nipple on the throttle body itself is not meant to be used as a manifold vacuum. Its purpose is actually for the charcoal canister. Leave it capped. As for where to get vacuum is by preference. As long as the vacuum is straight from the manifold (next to the tb where you get vacuum for your fpr should be a couple nipples, or some people get a vacuum block and install it. to the booster line and run lines to it) than it should be fine. Alot of people will say to run everything you can straight to the mani with no t's if possible so everything has its own vacuum signal but if your system is air tight I personally don't think it makes a difference. As for the external waste gate, and boost controller what kind do you have? I don't think it makes too much of a difference between brands but I always fallow the manufacturers recommendations as far as routing.

[compactfean]

As for the maf being after the bov it is to prevent the ecu from dumping more fuel in between shifts from the bov releasing already metered air. You can run the maf like that, or run it at the beginning of the intake and just route the bov to the cold air intake after the maf.

[bustedasska-t]

Thanks for the info. So what do you mean run the vacume block off the booster line I was under the impression that that wouldn't work because of the check valve. Can I just run a block off the fpr line?

[zmannz]

I've always run the reference for the boost gauge, fpr, and bov from one manifold with one attachment from that to the intake manifold. Never had a problem with it and it allows you to make good permanent seals over the unused nipples on the manifold. Easier to see the possible places you could be having a leak from there on out.

[compactfean]

I don't think, the fpr line would be big enough for vacuum to be accurate with a vacuum block. If you ran the vacuum block on the booster line in between manifold and check valve you'd be fine.

[bustedasska-t]

Are you sure about putting the block in the section of hose that goes to the intake. I don't make enough money to destroy stuff unintentionally. I do not have any of the oem vacume its all been removed except the 3 I mentioned. No plumbing left all hacked off during my free modding stage

[compactfean]

Yes it will be fine. Honestly you shouldnt even need a vacuum block anyways. This is how I have mine setup and you could do something close to this. Fpr, map sensor for avcr, and vacuum line for boost gauge off of intake manifold (small line next to tb) . Bov on its own line to intake mani (bigger line next to throttle body...provably one you ”deleted”) and then the actual vacuum nipple on the throttle body itself capped off. If you are running external waste gate than one is the nipples on the waste gate is supposed to go to intake mani, so that one you could t off of the bov. THE OTHER NIPPLE FOR THE WASTE GATE NEEDS TO GO TO THE CHARGE PIPING, NOT THE INTAKE MANI. this is also the same nipple that you would put your boost controller in series to...so it would go charge pipe nipple-boost controller-waste gate.