Your info is about 20 years
Your info is about 20 years out of date. The Subaru turbo design in the WRX, for example, uses a water cooled turbo. No idle time to cool it after hard driving. Turn it off and the water turns to steam and forces cool water to cycle until it is below the vapor point. No more turbo timers, no more coked engine oil. You are talking about Mazda RX7 design faults, not Subaru issues. All the best...