07 ss with a 60 trim turbo convert with hahn parts.ok so i have a auto meter guage and im not shure if its electrical or mechanical. my brother put it in the car. now all the sudden i lost boost. it doesnt read boost but reads vac. the gauge goes from 30-0 vac and 0-20 boost. now when i start the car it stays around 25 vac. when at times when i get on it it wont lesson 5vac. i hear the turbo. annd the blow off valve shoots off. all the piping to and from the intercooler to the turbo are tight. i double checked those. is it the guage or did i really loose boost? i had it 18psi. i just dont get it. i dont see any other lines to check. plz respond asap. i have to get this problem fixed before i can tune it this weeekend.