lol i mean the spike is the peak boost the turbo reaches then it settles to where it holds boost , mine will spike to 1.5 bar/22 psi then hold at 1 bar/15 psi , there is a diy guide on here how build a boost leak tester
 
i will take it for a drive 2moro if its dry on the roads and see what it peaks at and where it holds :) thanks for your help mate