Originally Posted by hutch959
with today turbos, the real reason to let them idle a few seconds is to make sure the turbine is not still spinning (or spinning fast)
spinning with no oil pressure is bad.
i think this is correct... but others may have input.
*quoted from PTP's FAQ section*
There is a misconception that the heat retained by the turbo blanket will cause damage to the turbocharger. This is not correct. Turbochargers are designed to handle well in excess of peak engine exhaust temperatures. Maintaining the heat of the exhaust within the turbocharger will not damage the turbocharger. However, as with all turbocharged vehicles, whether utilizing OEM or aftermarket turbochargers, it is very important to not shut off the engine directly after periods of heavy acceleration. It is advised by us, as well as all OEM and aftermarket turbocharger manufacturers, to allow a period of time to let the oil (and in some cases water) circulate and cool the turbocharger. We recommend that before shutting off the vehicle after periods of heavy acceleration, you should allow one to two minutes of idling to allow the turbocharger to cool down effectively. You may also consider purchasing a turbo timer to allow the engine to idle for a predetermined amount of time after you have left and locked your vehicle.