Working on one or our customers 350Z twin turbo, replacing the center cartridges on these Garrett turbos because they were blowing out oil. This GTM kit was riddled with little issues and looking over these turbos we found another. When GTM installed this kit they did not check the Wastegate arms length or closing point. So one of the turbos always had the waste gate open. When putting the new center cartridges in the turbos we shortened the actuator arms and set their opening pressures to match.
Your local speed shop located in Orange Ca, Project Import.