Technical question: VANOS

["Michael Ting" <lupin@xxxxxxxxxx>]

I was reading about variable valve timing technology. (credit to AutoZine)

First, there is Honda's cam changing VTEC. Then, there is BMW's cam phasing
VANOS.

I think it's safe to assume that VTEC costs more to implement than VANOS.
(multiple cams, as opposed to changing angles)
It's also clear that VTEC offers higher performance gains. The closest
example that I could think of, is E36 325s. Can I say zero performance
gain??

So my question is:
Why does BMW, being an advanced engine manufacturer, uses the cheaper, lower
performance gain technology? (surely price is not a big concern in BMW
engines)
Or why not implement something that uses both valve changing and valve
phasing? (like new Celica GTS' VVTL-i)

To add the confusion, sports cars like Ferrari's 360 Modena, and Diablo SV
is also said to use VANOS like, cam phasing technology. (Not sure on this
one)

The only answer that I can come up with is that smaller displacement is more
crucial in Japan. thus they're willing to put in the $$$ to research these
technological tricks.

Maybe someone can come up with a better explanation.


Michael Ting
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Learning the theories behind my wonderful bimmer. :)

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