Hi All
I echo what RobinA3 says you have NO set time or number or spins in the life of a turbo, few key things to remember are.. 1) if you have been running the car hard dont just stop, switch off and jump out let the turbo spin down and ideal for two min. 2) don't blip the throttle as your turn off the engine. 3) Use GOOD QUALITY OIL and change it as per the service plan and if youre running lots of mods half the interval between changes, it only adds £50 between services.
The fact about turbos is we only have about 5 or 6 mainstream produces such as Garrett (my home town), BorgWarner, Mitsubishi etc and they are found in everything from Audis to Volvos. I have owned a 1995 Volvo 850 T5 with a huge high pressure turbo running 2bar that had 180000 on the clock, our Citroen xantia 1.9TD with 500000 yes half a million miles (taxi for 9 years) with same engine and turbo. It had lots of clutches, the hydro-spastic suspension replaced and serviced every 6000 miles.
Summary, dont rape the turbo by turning up the boost (buy a bigger turbo), warm up and down the engine and use GOOD QUALITY OIL and change it as per the service plan.
Alex