[quote=tighed1]The problem with turbos' and the boost spike is that the boost is seen before the throttle body plate. If you let off of the throttle the boost will continue to push forward and can cause damage to the throttle plate. To relieve the boost spike a blow off valve (BOV) is used. The BOV senses the boost spike and releases it rather than letting it "slam" into the throttle plate or blow off your intake hoses.

My 8/71 super charger does have a BOV located after the output of the blower. It's not there to relieve pressure from boost, it's there in case you get backfire from the engine (granted if you produced enough boost it would override the BOV spring pressure). When I let off the throttle air simply stops flowing and thus the boost stops.

And yes the blower could be turning 6000 rpm and still show a vacuum condition if the load is not high enough. Example, accelerate at a medium pace say to 55 mph and observe your vacuum gauge. While the actual acceleration is occurring you will see boost, once 55 mph is reached and you are cruising you will see that your boost gauge is now showing vacuum. And yes, your supercharger is still engaged.

Make sense?[/quote]

Well, no.

All I can say is I notice with the ignition turned on, but the car not started, a small amount of power is sent to the intercooler pump. This reading made me think the pump ran anytime the key was turned, even if the engine wasn't started. Well surprise surprise, the pump doesn't run until the engine is started, AND it doesn't run when the car is shutoff, like previous thought. So my electrical readings said one thing, but in reality the pump did another.

Of course that doesn't mean I doubt Woody. At all. I think we're just victims of good 'ol over-engineering and now we're trying to unravel the mysteries.

some good info in this thread!