I recently bought a 96 SSEi and this is the first car I have owned with a */c. I work on an ambulance with a turbo diesel and have some understanding of turbos, and I thought that the only difference in the two was that the */c is belt driven off the motor, and the turbo is air driven off the exhaust. But I am finding that my boost gauge shows negative to no pressure when I am driving casually and only goes to positive pressure when I get on the gas hard. Also why does the boost "step up" as the tranny up shifts and actually drops RPM'*. I am used to a turbo where you have more boost with higher revs, and it drops boost as you up shift.

Sounds like your supercharger is working just fine.

I'll move this to the Forced Induction section so that it gets better exposure.

Sounds pretty normal. How much does it step?

It goes up about 2-3 psi when up shifting

Under part throttle that'* about right. WOT might show a little boost rise with upper RPMs, but not much.

So how much boost do these things put out at peek? Are you getting any benefit from the */C when it is in the negitive side?

I think 7 to 9 psi is norm on a Series II. You don't get any SC benefit when it'* under vacuum. It'* a function of the wastegate. Without it, you'd have boost at all times which would be murder on a gasoline engine'* MPGs.

Anybody remember that animation that shows the supercharger and its wastegate operating under different engine loads?

that was in this coblat thread

http://www.bonnevilleclub.com/forum/...ght=cobalt+gen

Thanks. Yeah that'* the jist of it. Not the same motor, but at least the same style of supercharger.