Vehicle: 2012 Subaru Sti
I have been driving turbocharged cars for a while now and I have blatantly accepted that before shutting down you must let your car idle for a few minutes after driving hard to allow the turbo to cool down. This process will allow you to extend the life of your turbo, however, I must say I have not heard of any scenarios where the turbo on these cars actually gets damaged by not following this process.
Are there any set rules on how long you should let your car idle after driving hard (i.e., keeping the turbo in boost, revving up passed 6000 rpm)? Is letting your car idle before shutting down an effective method for cooling the turbo? I have also used a turbo timer at one point, it may be useful to point out where this device has strengths in this matter.