06 SS/SC Vacuum Line routing

XJLIFE

Member
I am in the process of troubleshooting a bit of performance and I think I have narrowed it down to the vacuum lines. When I got the donor the lines were in rough shape and dry rotted. I think that when I replaced them I may have missed/swapped some lines. Does anyone have a good diagram/photo for the routing? Ideally the whole vacuum system including the brakes. I also might have removed the bypass valve thinking it was part of the evap system. Pictures of my routing coming soon.
 

DCMoney

Goblin Guru
I was just looking for the same thing. Found an old pic of my engine compartment before taking it apart. I have the small vacuum line from the supercharger going to a sensor on the side of the engine then to the manifold.

 

askiles

Goblin Guru
The hose that you have coming off of your bypass valve and going to a vacuum port on the intake manifold is incorrect. You should have a small electrician piece that controls this valve that will be in between there. It goes from the intake manifold port to the electronic control piece, then from there to your boost bypass valve.
 

JeffsGoblin

Goblin Guru
Am believing the bypass valve has connection points for two vacuum lines. One of said lines (maroon) runs to/from the bypass-valve solenoid and the other (green) runs to/from the supercharger.
Did anyone else notice the price on the little vacuum line (green in the pic) from GM? About $34!!!
 

ccannx

Goblin Guru
Am believing the bypass valve has connection points for two vacuum lines. One of said lines (maroon) runs to/from the bypass-valve solenoid and the other (green) runs to/from the supercharger.
Do you know what hooks up to the other/bottom nipple on the bypass valve right under where the maroon line runs ?
 

Parson Green

Well-Known Member
Do you know what hooks up to the other/bottom nipple on the bypass valve right under where the maroon line runs ?
There's only two nipples and the lower one is the one that should be connected, via vacuum line (maroon) to the solenoid. The upper one should be connected (green line) to the supercharger. People have apparently swapped these lines at the canister gadget with the idea that they will get more boost and/or better performance. Am believing it's a big mistake to muck around with the factory locations. Said swapping could also be a source of confusion to a purchaser of a donor vehicle ...

Technically speaking, the actual bypass valve is inside the supercharger. The plastic-canister gadget is the actuator.
 

askiles

Goblin Guru
There's only two nipples and the lower one is the one that should be connected, via vacuum line (maroon) to the solenoid. The upper one should be connected (green line) to the supercharger. People have apparently swapped these lines at the canister gadget with the idea that they will get more boost and/or better performance. Am believing it's a big mistake to muck around with the factory locations. Said swapping could also be a source of confusion to a purchaser of a donor vehicle ...

Technically speaking, the actual bypass valve is inside the supercharger. The plastic-canister gadget is the actuator.
DC and I were referring to the electronic piece in there...vacuum solenoid?? Not sure what exactly it’s called. The piece that actually has an electrical plug, and the vacuum lines run into and out of it.
 

Parson Green

Well-Known Member
Boost control solenoid.

That device (which could be more accurately termed a solenoid valve) is the means via which the ECU controls the manifold vacuum that gets applied to the lower port of the bypass-valve actuator (which is itself often called a bypass valve).

The upper port of said actuator also receives vacuum from the neck of the supercharger. Which should, btw, be a pretty clear indication right there that the operation of said actuator is anything but a straight-line (i.e., linear) affair.

So, is it some kind of trivial pursuit to seek information regarding the bypass valve and the logic behind when/if it gets opened or closed? Maybe, except am believing it plays a major role in determining boost pressures, and boost pressure is, after all, a matter of such significant interest that it has its own, prominently positioned gauge.


Recommended reading:


Am still wondering, though, why the pictured device has three ports. Am also wondering why the bracket that attaches said actuator to the supercharger body has slotted holes ...
 

askiles

Goblin Guru
That device (which could be more accurately termed a solenoid valve) is the means via which the ECU controls the manifold vacuum that gets applied to the lower port of the bypass-valve actuator (which is itself often called a bypass valve).

The upper port of said actuator also receives vacuum from the neck of the supercharger. Which should, btw, be a pretty clear indication right there that the operation of said actuator is anything but a straight-line (i.e., linear) affair.

So, is it some kind of trivial pursuit to seek information regarding the bypass valve and the logic behind when/if it gets opened or closed? Maybe, except am believing it plays a major role in determining boost pressures, and boost pressure is, after all, a matter of such significant interest that it has its own, prominently positioned gauge.


Recommended reading:


Am still wondering, though, why the pictured device has three ports. Am also wondering why the bracket that attaches said actuator to the supercharger body has slotted holes ...
Lol. Like we said, one of those ports just goes to atmosphere. There is usually a small piece of foam on it. It is the one with the small bit of around the port. One of the ports goes to the vacuum actuator and one goes to the vacuum nipple on the intake manifold.
 

Parson Green

Well-Known Member
Good to know this when the time comes to put all the parts back on our engine.

Just one thing, though.

Are there occasions when that "vacuum nipple" isn't really a vacuum nipple at all? Such as when the engine is pulling hard, the bypass valve is closed and all the supercharger boost is being routed into the intake?

Lol?
 
Top