Bypass Valve's arm move? Iam thinking mine is defective because when I watch it when the engine is rev'ed (causing vac), I dont see it do anything.

What is the lower hose "nipple" for? Ive got the lower one blocked and the upper one attached to the intake manifold for the boost/vac signal.

-Tom

 

top one hooks to the supercharger before the rotors (just after the tb), and the lower one hooks to the boost control solonoid, and the other side of that hooks to manifold vacume.

im not sure of your setup, if you have some pics it may help.

 

Blower is directly below the intake mani in this pic. Ive got the top nipple on the bypass valve connected to the manifold for the boost/vac signal.

So your saying the lower nipple should be on the manifold and the top should be after the TB and before the blower?



Whats this solonoid you speak of? This?

 

it would apear you are running the throbttle body before the blower, at least from what i can tell.

right on top of the blower there is a nipple, right by the bypass actuator. that nipple is what hooks to the top port on the actuator. the bottom one one hooks to the solonoid. that is the solonoid, its run by the pcm.

im not sure what would happen if you hook the actuator up to the manifold and try to run it like a wastegate on a turbo. the actuator doesnt have a heavy spring in it so id guess you would end up with pretty low boost. you could however run it with a boost controller like you would on a turbo car.

 

wouldnt happen to have a diagram of the ss cobalts vac system or know where I could find on do ya?

What exactly does the pcm do with this solenoid? Does it open up at a particular vac or boost levels?

Thanks for the info so far btw.....

 

the solonoid is there to controll boost under certain conditions. for example, in first gear it runs the solonoid at a 50% duty cycle, with my mods i see 12psi in 1st gear (normally run 15-16 in other gears). it also limits boost with cruise controll, and when the pcm detects a problem (limp mode opens the actuator fully).

not much to our vacume system. all we have is the bypass valve and evap. evap line goes to the nipple right by the throttble body, other lines as stated. i have a picture from alldata but am unable to post it.

 

ahh, so it basically bleeds off some excess boost if needed. I just want it so open some under cruise conditions or maybe idle. Hopefully I can get by without the solenoid. So ill try hooking the top nipple up to the TB and the lower to the manifold and see what that does.

Could you pm me the pic?

 

There is a bit of reading involved... but I have a diagram, and an explanation of the blower boost/vac system.

Edit:
Wrong link...
Here is the right one...
https://www.cobaltss.net/forums/showthread.php?t=78861

 

didnt see much of anything in that thread?????

 

****... sorry, wrong link...
Fixed it...

 

thanks!! very nice write up and info. Think an ebc would work on my set-up? I could patch it in the same but I have no pcm that does anything with boost. But you basicaly took the pcm out of the way with that install correct?