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Old 04-11-2011, 04:37 PM   #15 (permalink)
ChipsWithDips
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Drives: '11 Gunmetal 370Z MT
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Quote:
Originally Posted by 370Fitment View Post
just a little point to throw in here is that we've had problems with our bmw customers and a decent amount of others that have broken bearings inside the motor as well lost their motors because they've used different crank pulleys

the rotating assembly is balanced from factory with the stock front pulley so by changing it you essentially "unbalance" the motor...not to sure how this effects the 370s motor because in some cars this doesnt cause any issues for the most part

but just something to keep in mind...
What sort of bmw engines? From what I've heard and read, harmonics play a more important role the longer the crank is. If they were I6 that's a big difference from V6.

I'm still curious what the harmonic frequencies of a given crank would be and how those are determined. The hope is that the frequency is high enough for our motors that it's only an issue at a rpm higher than we are using (10k or something)
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