[judec]

Originally Posted by hotrod2448

So?

The pistons go up and down, cams and crank rotate while idling but, people still break in engines.

By that rational should you just run the engine wide open as hard as you can right from the get go too?

The hard break in vs. soft has been debated numerous times. There is pretty much no reason to get into it but, from my experience with the Evo, the guys who broke their cars in hard had a higher instance of puffing small amounts of white smoke out the exhaust on decel from oil leaking through the turbo seals.

I wont argue, but U answered your question in your post imo. Turbos only rotate, whether on an oil film or on ball bearings. There's not too much to break in there. On the other side the engine consists of quiet a few parts which are known for higher friction - especially piston rings, but also e.g. camshafts, which need a proper break in procedure.

On the other hand even when the engine is idling, the turbos rotate @ approx. 28000rpm. Not really low rpm if U ask me. So how would U like to break it in? Idle it for 2-3 days or what? Nono, I have a better idea - just interconnect the turbo shafts with the ventilator for the first 12 hours

Also if U are really liberal on the engine break-in, the turbos work at full rpm/full pressure any time - it does not take too much effort to spin them over 100.000rpm, an easy throttle blip can do that with those small turbos in N54, so no matter what, they work on full load from the beginning. Anyway I like to be on the safe side with cars and stuff, so I recommend to take it easy.

[hotrod2448]

From the Garrett website:

How should I break in a turbo?
A properly assembled and balanced turbo requires no specific break-in procedure. However, for new installations a close inspection is recommended to insure proper installation and function. Common problems are generally associated with leaks (oil, water, inlet or exhaust).

So, I guess I'm just overly cautious.

A quick throttle blip is different than sustained high temp, high load right off the bat but, whatever...

[07335]

I went by to BMW to get a part number list of the replacement parts for my engine. Since there were questions on what BMW had actually ordered, I have attached the printout of the parts they gave me. The price for each of the turbos over here in Germany is 1,293 Euros ($2,041-each). So, brand 2 new turbos will be in on the 14th!