turbo timers are not essential, please have a read of the following extract from turbotechnics website, if you follow this advice you wont go far wrong.
Useful tips when driving any turbocharged engine, whether it be petrol or diesel, are to always allow the engine to warm-up fully, until the water temperature gauge reaches normal, before full throttle is used. Try to plan the end of your journey sympathetically. Don?t use full throttle or allow the engine to labour during the last few miles. This will prevent excessive heat build-up within the turbo when the engine is turned off. Also, when coming to a standstill, try to leave the engine idling for a few extra seconds to allow the heat to decrease. Never rev the engine just as the ignition is turned off. Remember the turbo spins at a far greater speed then the engine, but is lubricated with engine oil. Once the engine stops the oil supply ceases. In reality, none of the above traits will cause a turbocharger to fail immediately, but repeatedly over a long period, they could reduce the life of your turbocharger.
