I have and autometer boost/vac gauge and i have tried every vacuum line going to the intake, like the instructions say, and all my gauge reads is vac pressure and at wot it goes to zero. I am running a vortech s/c not sure if there is some place that i don't know of that i should connect the line. I was thinking of tapping in to the air intake tube from the s/c to the throttle body but not sure if that will give me a accurate reading. Any suggestions??