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01292013, 04:13 PM  #155  
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01292013, 06:30 PM  #156 
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More please, can you or anyone else elaborate on how this helps.
This will be manual only, I am leaning S4 with Stasis. Again I should have stated in the OP this is a XDrive vs S4 debate. Last edited by seisspeed; 01302013 at 02:13 AM. 
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01292013, 06:35 PM  #157  
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Given the 335i RWD with a sport suspension has a slightly lower ride height than the 335i AWD, does the AWD have a lower center of gravity? Thanks Bruce
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01292013, 06:38 PM  #158 
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That's easy then, S4 if you want performance. 335xi if you want everything else.

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01292013, 06:46 PM  #159 
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and THAT's why i'm neither doing anything extreme NOR on the cheap. everything i'm doing is from EXTREMELY reputable vendors.
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'14 Estoril Blue II F30  335i  ZMM  ZPP  ZTP  ZPS 
2TP Traded 9113 '13 Estoril Blue II F30  328i  ZMM  ZPP ZDY  ZTB  403  465  494  4DX LC (Black)  6NL 
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01292013, 07:48 PM  #160  
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01292013, 08:51 PM  #161  
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If you only consider the nonsport 3 series lines, then yes, the COM would be marginally lower. The larger effect on the dynamics involve the pitch and yaw moments of inertia. This calculation is proportional to distance squared, so sticking a lot of mass in the front of the vehicle will throw off the natural balance of the car more so than you'd think. I know driving dynamics are more complex than this, but the 5050 balance of the BMW is what gives the legendary handling... As mentioned, you can still get the DHP package on xdrive, which allows you to stiffen things up.
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01292013, 09:14 PM  #162  
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But that stasis suspension, brake, exhaust and engine tune probably bring the S4 into M3 territory (well stock M3 of course), comparing it to a 335ix is at that point laughable. Sweet rims too...
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01302013, 01:07 AM  #163  
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01302013, 02:11 AM  #164  
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01302013, 02:15 AM  #165  
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Although I am intrigue by APR's pulley system. 

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01302013, 09:22 AM  #166 
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Oh OK, for some reason when you said an "S4 with Stasis" I assumed you meant the full on package  touring or challenge  which are both lots of $$$. There are some ECU tunes for the 3 series, check out Dinan for example. Stasis doesn't have a B8.5 ECU tune (assuming you're shopping for a 2013) yet, but it's expected any day now.
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01312013, 02:12 PM  #167  
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Thanks Bruce
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01312013, 07:36 PM  #168  
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(x * 135/2.2 + 0 * 3461/2.2)/(3596/2.2) >= .01m implies x >= .256m So if the xdrive hardware is .256m = 10 in lower than the current CM, you would be correct. I'll check out carsim at work tomorrow and might be able to get a rough guess of where a nominal vehicle's CM is. My guess is it will be quite low and probably less than 10 in above the drivetrain  based on nothing at all but my best guess Of course the 335 is heavier and thus CM is less affected by xdrive...
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02012013, 10:27 AM  #169 
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FWIW  the default CarSim DClass sedan has the sprung center of mass .54 m above the ground. The wheel center is .335 m above ground, which should be *at least* lower than the driveshaft + xdrive hardware. Thus the difference is .205 m which is not enough to lower the CM of a 328ix as compared to sport suspension 328i using my calculation above.
The GT model in carsim (supposed to be a Porsche) has the CM .39m above ground and wheel center .325m above ground. So for a sports car with low CM the xdrive would do nothing to the CM.
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02012013, 02:57 PM  #170  
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From looking at the drawing of xDrive for the 335i sedan on the BMW website, the extra hardware of xDrive looks like it is roughly in the same plane as the driveshaft, which is roughly in the same plane as the wheel centers. According to the example above, the sedan's wheel centers are .205m / 8" below the COM, so that would put the extra weight of xDrive lower than the COM. If so, that should have the effect of lowering the vehicle's COM with xDrive. I'm also having trouble following the effect of the 10mm lowered ride height for RWD with sport suspension. In terms of meters as the unit of measurement used in the example, that 10mm is only 0.01m. Am I missing something? Thanks Bruce
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02012013, 05:01 PM  #171  
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edit  I attached the data for you to see.
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Last edited by drob23; 02012013 at 05:07 PM. 

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02012013, 05:55 PM  #172  
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02022013, 02:52 PM  #173 
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I did, I wanted to like the S4 so much but after driving it, I could really tell the front wheel bias. Never owned an Audi so the difference was pretty apparant to me. I also was really dissappointed in the dated interior. Just doesn't hold a candle to the F30. Now if I had to choose between an E90 and the Audi, I would have taken the Audi just on the basis of how horrid the E90 interior was.

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02022013, 04:48 PM  #174  
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02032013, 01:15 AM  #175  
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SOLD: 2012 335i Mineral Gray M Performance Exhaust/Brakes/Suspension/LSDBav Stage 1/AMPER CP/IC/DP/OC  Dinan CAI/N55 PWG BIG TURBOBMWF30.com 

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02032013, 01:41 AM  #176  
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