I just installed a boost gauge(VDO) in my Rivi and it showed about 1 to1& 1/2 Lbs of boost.So I took the one out of my Grand national ,it is an Autometer and it reads Vac. and boost. It reads the same amount of boost as the VDO gauge.Its reading 17 to 18 lbs of Vac. I have it Teed in at the throttle body where it goes to vac modulator on trans. Whats up with that?????

I might add also that you CAN hear the supercharger when you stomp it BUT my wifes new 300C SPANKED MY A%#! My car does NOT feel strong at all.

Your problem is that you have it hooked up to the vacuum modulaor vacuum line. That'* right after the throttle body and will never see boost of any kind, only a maximum of atmospheric pressure.

You need to hook the gauge up to either the MAP sensor line or the line that goes to the Boost Bypass Valve Actuator (round black thing near throttle body). It has 2 vacuum lines on it, and one will be the correct one, but I don't have a Series I so I couldn't tell you which one it is. I'm sure someone'll know.

Your Rivi won't have a MAP sensor. That means you have an empty vacuum port on the tree by the BCA. If you have no empty port, get a vacuum tree from an SSEi, then you will. You can use that port for your gauge.

Wait, you won't have any empty ports. But what you can do is snag the FPR vacuum line from an SSEi. It will have an extra port on it that the MAP sensor usually uses.