1st, The turbo is spinning the whole time the car is on. It never stops when the car is running. So there for, the purpose is of the turbo timer is to keep oil running through the turbo to cool down the center housing. This is critical after a hard run, where the turbo can spin at VERY high RPM and reach temperatures as high as 1600 degrees. If an engine is shut down immediately after a hard run, the turbo may still be spinning without any circulating oil, and even if they are not spinning, the turbo can still be very hot causing oil coking. Extended and repetitive oil coking within the oil lines and center housing of the turbo could result in clogging problems and a damaged turbo.QuickSilver said:I'm curious, does any one know what leaving the car in idle will do for the turbo?
The oil pump is on, but do you need to keep lubicating a part that's no longer moving?
I've read that the coolant running through the turbo will recirculate regardless if the engine is on or not.
Anyone care to enlighten here, cause right now, the need for a timer does not seem to be there (driven hard or not).
That is incorrect. According to Subaru's own document, the cooling system is specifically designed so that the coolant will continue to flow through the turbo even if the engine is shut off. That's why WRX's manual does not mention cooling down or use turbo timer at all.AaronC said:
2nd, The water pump is powered by the belt running from the crank pulley. This means if the engine is not running coolant is not pumping throughout.
I took a look at what you were talking about, and apparently the WRX has a "Passive Cooling" system, that does not use the water pump. This would allow the turbo to cool faster when the car is off, but if you are running higher then stock boost the turbo is still VERY hot, and having oil sitting in the turbo cooling "slightly" faster is still a band-aid for a proper cool down.Foxbat said:
That is incorrect. According to Subaru's own document, the cooling system is specifically designed so that the coolant will continue to flow through the turbo even if the engine is shut off. That's why WRX's manual does not mention cooling down or use turbo timer at all.
I think they did address this on a completly stock WRX. I seriously doubt that the turbo needs to cool down on the car stock, although, as someone mentioned earlier, it cant hurt. If the boost level is left at 13.5 PSI, then the trubo does not get nearly as hot as running it at, say, 15 or 16PSI like many of us do. The turbo hits much higher RPMs then subaru designed the system to support, when you are upping the pressure with a boost controller.QuickSilver said:I'm not disagreeing w/ you, but I'm very surprise Subaru did not address this problem?