What criteria activates bypass valve solenoid?

Booba,

I tried your smoke test and was not able to get the smoke to come out of anywhere, although it did go through the exhaust when I started it. Also when you stated that the coupler is designed to fail, it is not designed to fail to keep the shaft from being damaged. It is there for misalignment between the input of the blower and the shaft. If the couplet fails then you have the pins hitting each other and that will damage the blower beyond repair. The coupler is the same type you would see in any other industrial application where you have 2 shafts meet. They are designed to take up for slight angular and parallel misalignment. Look up Lovejoy coupling they do the same thing.

I am still not getting any boost. Sometimes it will go up to 1-2 psi if I ease into it, then it drops back to atmospheric pressure "0".

Sometimes the engine feels weak then it comes alive, but still no boost.


Jeff

If you leave the coupler destroyed then of course it'd going to hurt the blower. The thing is the blower will make ALL KINDS of noise when it happens before the the blower destroys itself. I said the coupler is designed to go out first, I never said it was designed to protect anything. Yours isn't making any noise, so I'd think the coupler is fine. Can you see the BBV move when you give it gas?

My coupler isn't making any noise and is solid, so either they started using solid couplings sometime or it's been changed. The butterfly moves when I rev it. It closes when I shut the engine off and opens when I start the engine.

I am not new to the M series of superchargers, I came up with all the bearings back in the late 90's for rebuilding M90's in fact it wasn't 3 months after I posted the information on the drive bearings, shaft seal and rear needle bearings that someone started selling a kit on Ebay. I am new to the way the supercharger is setup with regards to the bypass valve. Most of them are operated by vacuum only (to open them), this one has a port and solenoid to allow pressure to be piped under the diaphragm that will force the bypass to open. It seems like as soon as I go into boost either the solenoid causes the bypass to open or the shaft starts spinning at the coupling drive or the pressed on flange for the pulley. I made witness marks and it's not slipping there so something is going on.

I used to buy up a lot of blowers with broken spring couplings and make my own solid couplings out of Delrin before you could buy them on Ebay. The coupler is not designed to fail first at all it is there for misalignment and that is it's only purpose. The spring coupling was designed for the same purpose but was supposed to lower the NVH by taking up the slack in the coupling and preventing the chatter that would happen with the coupler and differing loads on the rotors at idle.

Jeff