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Originally Posted by clarence
So u're now saying BMW doesn't have a consistent & predictable defect rate.
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No, that's not what what I'm saying at all. I never said anything like that. If anything, I'd say that they're able to build engines in a way that identifies defects before the engine reaches the dyno, and that each engine is built from beginning to end as it's final outcome intends. It's very easy, and cost effective, to recycle out-of-spec components like a block or head casting. Verification of dimensional accuracy is 100% automated, so it's a cheap way to dramatically reduce the very kind of variances you're claiming results in this binning approach.
Quote:
Originally Posted by clarence
I would say they already have enough statistics on the N20 as it's already in production for over 2 yrs. They know roughly how many units per mth that are considered as defective, everything else being equal. So wht do u think they'll do to those defective units, junk them? If they run out of defective units then they'll have to use good units, but it's only for the low compression version cos the high compression version is built as a U0 right from the start. It bears no extra cost to them as the BOM is the same for the whole N20 family (see the article).
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You should really step back and listen to what you're saying. Essentially, it's one way for one engine, and an entirely other way for another. They're able to build U0 engines entirely to spec, but the O0 engines are binned according to their output. Does that make any sense at all?
Quote:
Originally Posted by clarence
As mentioned before, the high compression version have different pistons but the low compression version is identical (again confirmed by ETK & BMW China technical rep). So how do they choose between identical engines to be a 20i & a 28i (talking abt low compression version only)? Randomly? Or is it better to use defective ones or underperforming ones (for a 28i) & detune it to be in-spec for a 20i? How complicated can that be when the defective rates are low?
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So you (or someone) has verified every single part number and every aspect of the software running on these two engines? There is a gulf of difference between "they are identical" and "we have not identified a difference".