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      01-24-2013, 10:19 AM   #316
sean10mm
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Quote:
Originally Posted by bradleyland View Post
I'm well acquainted with semiconductors (pn junction anyone?). I'm also well aware of the binning required in the semiconductor industry. However, comparing the two is... well, stupid. There's no other way to say it.

a) Semiconductor manufacturing is much, a much, much younger technology than metal casting and machining.

b) The tolerances for semiconductor performance operate on a nanometer scale, versus engine tolerances. Even for interference fit parts, tolerances are typically 0.0000 inch (ten-thousandths of an inch). There are 2540 nanometers in 0.0001 inches. So, the precision required to manufacture a semiconductor is several orders of magnitude greater than high-precision machine work.

c) Binning and yields are an effect of the technology limits encountered in semiconductor manufacturing. This is not something that engineers intentionally designed in to the process. In other words, it's not desirable. If semiconductor manufacturers could eliminate binning tomorrow, they would. Why would we (humans), having the technology required to manufacture on a nanometer scale, settle for binning in something as well known, and well developed, as metal machine work?

I do not accept the binning assertion on the basis that I don't believe it is necessary. Stated another way, I don't believe that BMW would have significant enough yield issues when manufacturing the N20 to necessitate binning. There is, otherwise, no justification for the binning hypothesis.
Semiconductor industry veteran here chiming in to agree with you. The idea that BMW is binning engines based on dyno results is insane. Comparing semiconductor manufacturing and automotive engineering isn't even apples and oranges, it's like comparing apples and elephants.

Put another way, BMW would have to be the most incompetent engine builder in the automotive industry to be seeing enough variation in engine-to-engine horsepower for binning to make sense. Henry Ford probably didn't see a 33% variance in horsepower from one Model T engine to the next, so I'm pretty sure BMW isn't seeing it now building the N20 with fucking robots.