Quote:
Originally Posted by clarence
The low compression U0, which has no physical difference to the O0, is only fitted to E84 20i, F25 20i, F20 25i, E89 18i & E89 20i, plus any of the F30's & F10/11 that needs low compression ratio (decided by BMW according to specific market requirements, & it isn't a customer selectable option).
If u compare how many high compression U0s they make vs low compression U0s, u can see the high compression U0 is made in far larger numbers than the low compression version. I don't have the numbers off hand but u only need to compare annual sales of the various platforms plus which market those platforms are popular in (e.g. E84 & F25 are mostly sold with diesel engines in EU).
The limited option packages u talked abt is US-specific. For all other markets all the options are a la carte (as long as it's legal), so someone can spec the car as they wish & then apply aftermarket tuning. Remember for a market such as germany the price delta for a 320i & 328i is 4,000 euros.
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That is an interesting note (bolded), but I think it supports my hypothesis better than yours. If the production runs are smaller, then the binning approach makes even less sense. I'm still not convinced that BMW is concerned with broad scale modding affecting their bottom line.
Also, think about the entire argument you're making about BMW trying to protect their bottom line against chip-tuned 320i cars competing with a standard 328i. A chip-tuned 180 HP N20 is capable of 230-ish WHP according to the dyno chart referenced here:
http://www.f30post.com/forums/showpo...2&postcount=14
So customers could still buy a 320i, then chip tune it to get factory 328i power. In this case, BMW has failed in the goal that you set for them.
Quote:
Originally Posted by clarence
We do not know the exact power/torque output variances that exist between the engines, as well as the percentage that falls below that range. One thing is certain is that it's very rare to have engines that produce exactly the same power & torque rev for rev, so variance do exist however small it is. This is not exclusive to the N20. We also do not know how tight the standard is used by BMW. It could be that, judging by the dyno plots in this forum on stock O0's, BMW uses an extremely strict set of criterias for their tests. As they dyno every engine made, they can easily identify which engine is a potential candidate to be a U0 if it needed to be. Remember the production numbers for the low compression U0 is much much less than the O0, they can easily select those that give dyno numbers that lie in the lower end of the acceptable range.
As to why it's logical for them to detune the bad ones, that's to protect their bottom line. They don't want a 20i to be tuned to a 28i with no side effects. That's especially true for markets that have very high taxes.
Simply speaking their bottom line will be hurt if the engines can be upgraded by a simple & cheap remap. So far nobody has managed to bring a 20i up to 28i levels without major effort.
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Then they've failed for the reasons I've outlined above. I just can't accept this as the rational motivation, as it is not satisfied by the solution.
Quote:
Originally Posted by clarence
I know all these JIT manufacturing & stuff. With BMW engines it's a bit different. The majority of N20s are made in Munich, & they supply exclusively to other plants worldwide. Apart from Munich (& other German plants) it takes at least 1 mth for the engines to reach the respective assembly plants. That's the reason why for a lot of markets it takes many mths from ordering to taking delivery (e.g. production takes place 1-1.5mths after ordering) and also the SA made cars have an extended lead time.
As for randomness, it doesn't matter cos a good one can always be detuned. The surplus good ones won't be sitting idle cos they'll be used to fulfill the lower grade demand. It doesn't cost BMW anything to do things this way as they already dyno every engine.
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Ok, so sometimes the 180 HP U0 engines are made from defects, but sometimes they're not. Doesn't this also degrade the strategy you've outlined?
Quote:
Originally Posted by clarence
One thing to note is that the high compression U0s (i.e. those BMW that have complete control in terms of production numbers) are fitted to all BMWs made in German plants, except for the E84. Whereas the low compression (i.e. those binned) ones are fitted to all cars made in Spartanburg (F25 & E89). It's probable that when JIT is needed & achieveable then they won't use the binning approach whereas they'll use this approach when JIT is not achieveable. A related question is why BMW, after spending all these money, do not use the high compression U0 on all the platforms that use that engine, rather than wht they're doing now.
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Interesting, but there's still the matter of motivation. Simply protecting their bottom line still doesn't make sense for the reasons outlined above. What if, instead, they use the low-compression engine in foreign assembly plants expressly for the purposes of JIT. If all your engines were identical, you could just flash them with the appropriate software and send them down the line. I don't have an explanation for the lower than normal tuning results from the 20i, but maybe there is some other unknown factor?