1G Vacuum Line Set up Help. Taboo diagram accurate?

[Avatar_Squadron]

I know this is a well discussed item, but i've been finding a lot of conflicting information and i was wondering if someone could clarify.

I'm trying to set up the vacuum lines on my 1g turbo, using the taboo diagram as a guide

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However, while reading other threads, people are saying that it's bad to T your MBC to your blow off valve as this causes problems? MBC Set up

So, why does the taboo diagram say to do exactly that? Was it made before people knew this was a problem, or is it only a problem if you're running a non-stock setup. Should I ignore the taboo diagram in this regard or follow it?

Also, I'm having trouble finding the second inlet on throttle body where the taboo diagram shows the BOV connecting. When I bought the car, the PO had the BOV connected to TB port P and had a custom tap on the TB elbow running his boost gauge, so i dont trust anything about how he set it up and i dont see any pictures in either my haynes or chilton's manual about where it's supposed to be. (and yes, i have a new TB elbow to replace the one he screwed up)

Lastly, this one is probably dumb, but i just want to confirm, the FP solenoid has the vacline hookups on opposite sides of the solenoid and the evaporative solenoid has both lines next to eachother (as shown in the diagrams). My solenoids are flip-flopped from how the diagram shows them (what i think is the evaporative solenoid is to the left of what i think is the FP solenoid)

Incase it's relevant, i'm running a stock 1g with the EGR removed and blocked off and the evaporative canister removed and the hard line blocked off. I have a screw-style MBC to replace the stock boost control solenoid.

 

[jcarmichael]

my mbc comes off my j pipe from, my turbo down to my waste gate there use to be a line that went from jpipe to waste gate cut it and put it in there works for me. when i tried it from my bov to waste gate wasn't working properly. if I remember correctly.

also if you dont have egr stuff block off all pots but the p put your boost gauge line there and then there is a spot in the middle of your intake towards the fuel rail side where your bov will run to if I can get a picture of it today sometime I will.

 

[crash89]

Yes, there are some contradicting things that come from the Taboo diagrams as to what is the best way. Such as the MBC. For the boost controller to work the best and most efficient you will want straight from the boost source (turbo compressor cover or J-pipe) straight to the wastegate in the shortest route possible.

As far as the boost gauge, Ive never seen or heard anything about the port "P". Ive always seen and ran my gauge just from the fuel pres solenoid into the cabin..

 

[knochgoon24]

I have my boost gauge ran from one of those ports. I just can't remember which one at the moment.

2 of those ports are post throttle plate (I think P & E) while the one is before the throttle plate (A?).

I'll check when I get home tonight.


I have my BOV ran from one, my boost gauge off the other, and then the BOV port is connected to a GM 3 Bar map. I think I have the A capped off. With everything connected this way, everything has its own line. No T's anywhere.

 

[99gst_racer]

So, why does the taboo diagram say to do exactly that? Was it made before people knew this was a problem, or is it only a problem if you're running a non-stock setup. Should I ignore the taboo diagram in this regard or follow it?

That Taboo diagram was created a decade+ ago back when that was commonly accepted. Since then, many people have discovered shortcomings with that configuration. Teeing into the same line for the BOV and wastegate can cause pressure fluctuations, which can lead to BOV flutter and boost spikes. It's just good practice to keep their pressure sources separated, just like from the factory, and a more up to date diagram would/should show that.

 

[jcarmichael]

forgive the j pipe had to jbweld my nipple on because cx racing intercooler kit didnt come with a nipple on the j pipe and was having issues running it from bov to waste gate as stated above. in the throttle body picture if you go to the right of the pic towards the eninge on the intake there is a little spot possibly hidden behind wires where your bov will go to. but all other ports on throttle body are for egr stuff block them off if youve already blocked off your egr. and use p for boost gauge.

 

[Avatar_Squadron]

Alright... I figured it was just that the taboo diagram was out of date. Thanks for the info there.
(thanks for the pictures jcarmichael)

I'm still a little confused about the Intake manifold. I only have 2 nipples (minus the TB nipples) for vac lines to connect, one on the back for the brake booster, and one on the front between cylinders 1 and 2. I have my FP line coming from the nipple between 1&2 , but the taboo diagram shows a second nipple near cylinder 4. It could be it's just a topology diagram so relative locations arent accurate, but if i use the nipple between 1&2 for BOV, where is the source for the FP system suppose to be?

EDIT: i also have another nipple on the 'front' near the TB for where the PCV valve connects.
I also want to point out i'm basically setting my vaclines back up from nothing. The PO clearly had everything all messed up so I dont have any reference points for where things are supposed to go beyond what my tech manuals say. They both kind of gloss over the exact location of things assuming that you've already seen it hooked up...

 

[LiquidX]

A turbo intake manifold should have 1 on the back for the brake booster and 3 on the front for BOV, PCV, and FPR.

 

[jcarmichael]

the one between injs 1 and 2 goes to the valve cover if you go to the right of that you will see another nipple somewhat hidden behind wires probably I go to break in 20 mins Ill grab another photo.

 

[Avatar_Squadron]

Thanks LiquidX, That's what i wanted to know. I have 2 intake manifolds so I will recheck both for that third nipple. If the manifold really is lacking the third nipple, would I want to hunt down a turbo manifold, or would it be sufficient to just run BOV on TB port P and T the FPR line for the Boost Gauge?

 

[jcarmichael]

behind injetor one is the one going from the intake to the valve cover behind injector two is the one coming from bov

 

[9!'clipseDOHC]

It sounds like you are using a N/T intake manifold. The turbo intake manifold has an extra vacuum port for the BOV as seen here:

 

[Batmobile 1G]

You should only have 4 vacuum lines if your emissions control is deleted. the 4 vacuum lines should be BOV, Fuel pressure regulator, brake booster, and the waste gate, as far as a boost gauge you can run that off of p but if you have a good idle you can T is off of the fuel pressure regulator in my experience you get a more accurate boost reading from there.

i forgot to add pcv to the above post

 

[Avatar_Squadron]

Thanks 9!'clipseDOHC. That picture really helped. Definately NT intake manifold, but the other one is a turbo so I'll just switch them out.

I wasnt seeing the vertical PCV nipple.

Thanks for the help guys

 

[jcarmichael]

this might be useful to you then, under tech in the vfaq section how to get your intake manifold off wish I had read it over the weekend when I was doing my hg would of saved me sometime.

http://www.dsmtuners.com/forums/art...257-tricks-removing-your-intake-manifold.html

 

[9!'clipseDOHC]

Thanks 9!'clipseDOHC. That picture really helped. Definately NT intake manifold, but the other one is a turbo so I'll just switch them out.

I wasnt seeing the vertical PCV nipple.

Thanks for the help guys

No problem, glad to help! A lot of people don't realize there is a difference from the N/T and turbo intake manifolds. Plus with all the turbo swaps and interchangeable parts it's not uncommon to find turbo bits and pieces in N/T cars and vice versa.

 

[knochgoon24]

Alright. Just went out and checked my car. Here's how I have stuff run. (Emissions deleted)

P - BOV
E- Boost Gauge
A - Capped off
BOV - GM 3 Bar MAP
FPR - Still just the FPR solonoid
Brake Booster - Still just the brake booster

I don't know how well the P port would work for others. I have a SSQV, and it doesn't take much of a pressure change to get that to pop open/closed.