What would happen if the bypass valve on the GM m45 SC were to die....

I assume it would either get stuck open or stuck closed (or possibly flutter around)....
(is there a spring or anything on the valve(like a TB springs closed at rest)? like if the diaphram was SHOT... is there anything else acting on the valve? )

so i know if it sticks open you will loose almost all boost. but would it continue to run? just turn back into a N/A engine pretty much? (with the loss of some HP from spinning a big usless set of rotors)?
Would any damage to the SC result (from the rotors spinning freely without any resistance, like it is bad to rev an engine to 5000rpm in neutral)

and then on the flip side....

what if the bypass was stuck closed? so your bolwer would be cramming air into the engine at all times... obviously you would have some aweful MPG, and prob a real high idle, if it idles at all..... but what else could or would happen? (and what did cars do back before they had bypass valves... isnt that a recent adddition to the newer generations of SC's i thought i saw that the SC's from just last decade or so had no bypass)
I would think this situation would be more harmful to the blower than stuck open would, but maybe not if older SC's never had one to start with.

It should stick so that you have no boost..... or actually very little boost. I'm sure if you really get on it it'll push a little air into the engine.

If it got stuck closed, and you were always boosting I could see it killing your MPG. As far as your idle, I don't think anything would happen. I've taken the bypass on my GTP and closed it manually with the engine running and it didn't seem to do anything to the idle. I think really the worst of your problem would be a noisy ride. One thing the bypass does do is make the blower stfu.

NO.

Vacuum holds it Open, IE low load, high Vac, open possession as to not work the blower.

when the valve fails, spring pressure holds it closed, causing a loss in gas millage and increased intake air temps.
i will also come into boost at a lower RPM, and make more noise at a lower RPM.

Chris


'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08