[jonm42]

Originally Posted by retrodrive

Not sure what oil bmw uses but if it is fully synthetic, you have nothing to worry about. If it is not synthetic, change it.

It comes from the factory with a full quotient of synthetic.

[T Bone]

I used to race Turbo cars and the best way to cool down is actually drive very sanely and off boost for about 5 minutes before shutting down.

Back before synthetic oil was vogue, processed oil coked (fried into solid bits which kill the bearings) very easily if you shut off after some fun times.

You should NOT use a turbo timer or let it idle after a hot run, this does very little. You need to stay off boost and get air over the rad and oil cooler to cool the entire system down before shutting off.

Without a steady flow of cool air over the rad and oil cooler, the turbos stay hot for a long period of time which leads to coking......

If you have the patience to let your oil warm up to about 80 degrees celcius before you beat on it, you should have the patience to drive calmly for 5 minutes before shut down......

[Corey]

Originally Posted by T Bone

You should NOT use a turbo timer or let it idle after a hot run, this does very little. You need to stay off boost and get air over the rad and oil cooler to cool the entire system down before shutting off

It does a WHOLE LOT more than just shutting the car off. Keep in mind a lot of turbo cars don't have stock oil coolers or water cooled turbos. It may not be the BEST solution but I certainly wouldn't tell someone not to use one..

[Zeiss]

Yeh good points.

Definitely depends on the situations, climate being a crucial part. If we talking about 335i, its absolutely unnecessary. From my experience and what people have told me, even running 400bhp cars with chargers, you don't need a timer. Just be easy on the throttle and leave the car on for awhile and wait for it to cool down. In most cases people like just have the gadget in their cars because it looks professional

[retrodrive]

Well,if it is fully synthetic from the factory then it will not damage the turbos. It does not "cook up".

[freddiemac]

Originally Posted by retrodrive

Well,if it is fully synthetic from the factory then it will not damage the turbos. It does not "cook up".

Modern synthetics turns to harmless ash in extreme temperatures, will not harm the oil seals and bearings in th turbos. My friend used to work for Garrett turbo chargers used to do these tests.

So
turbo timer = ricey mod