Quote:
Originally Posted by jacobe92
Factory tune = Power within motor tolerances. Installing a tune to get more power out of the motor exceeds it.
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I disagree that the factory tune is within the motor tolerances. The factory tune was also spinning the crank hub out of place. Installing a tune only amplifies that possibility of this happening. Everyone drives differently and as such some spins on stock cars and most spins on tuned cars.
Factors like using the kickdown on the DCT extensively including the use of the kickdown during manual mode to drop it to the lowest gear introduces a huge rush of torque that puts a lot of strain on the crankhub causing it to spin apparently. This should not be happening as the crankhub is supposed to be keyed/pinned to the crankshaft. I myself am surprised BMW managed to overlook such an important factor on the S55 but some have mentioned the reason of fact that it is a failsafe from the engine grenading when the hub spins. Either way, it is a shitty fail safe system and a cost cutting measure to not have keyed/pinned the crankhub in the first place.
This happens both on stock and tuned cars with the excepetion that you do not hear much on stock cars happening because they probably are not even on this forum or the sample pool size of those having bone stock cars on this forum is low.
I am not substantiating that BMW should pay for cars modified nor encourage a culture that warranty should be fraudulently be claimed but this problem is an inherent weakness in the engine that is happening even on stock cars and BMW warrants them. If this is not happening on stock cars at all, I think we can agree that the factory tune power is within motor tolerances then. And this part of the sub-forum Engine / Drivetrain / Exhaust / Bolt-ons / Tuning would probably be empty.