For those interested in Acceleration...

LANDLORD · 06-28-2010, 03:11 AM

I really love the way the X6M is able to accelerate from a dead stop. It really can surprise almost anyone next to you. No hint of tire slip, and an immediate surge forward that is unusual for the weight of the vehicle.

The M gets the same Final Drive ratio as the 35i which is 3.91.
The 50i gets a ratio of 3.64.

The 2011 8 speed transmission will improve the mileage and efficiency but it may not accelerate quite as well. Shifting gears takes time and will probably reduce the acceleration rates. Please see below:

2008-2010 50i:
1st gear ratio 4.17 x Final drive ratio 3.64 equals effective gear ratio of 15.1788.

2010 X6M and 2008-2010 35i
1st gear ratio 4.17 x Final drive ratio 3.91 equals effective gear ratio of 16.3047.

2011 35i and 50i with 8 speed transmission:
1st gear ratio 4.71 x Final drive ratio 3.15 equals effective gear ratio of 14.8365.

If someone would swap the 8 speed into an M (if it could handle the torque) you would end up with a Final drive ratio of 18.4161 in first gear! That could potentially break things and would be a very short 1st gear. They would have to reduce the axle ratio to use this transmission, possibly to the 3.64 in the 50i which would result in a final drive ratio of 17.1444, higher than the current M. Will the 8 speed end up in the M? I rather doubt it at this point.

Overall these are very stout numbers for all of the X6's and explains some of the quick off the line acceleration from these vehicles.

flipside99 · 06-28-2010, 06:57 AM

BMW claims that the new 8-speed shaves .2 seconds off the 0-60 times in both the 35i and the 50i.

kmg99 · 06-30-2010, 06:57 AM

Don't forget the torque convertor multiplication at stall speed in your calculation as it can have a significant effect on torque multiplication and vehicle performance.

The 8-speed would likely be marginally quicker; although with the X6M's extremely wide torque band the difference will be very small.

LANDLORD · 07-01-2010, 12:17 AM

Good Point, I have been wondering about the torque converter, and if the computer can change the performance of the torque converter at all. It seems to reason, that say during launch mode, the computer may be able to adjust the torque converter's response. It seems as if in sport mode the torque converter does react slightly differently.

I wish I knew a BMW engineer who could really divulge all of the abilities of the computers control of the vehicle.

06-28-2010, 03:11 AM	#1
LANDLORD Turbo Engines are Fun 24 Rep 252 Posts Drives: 2010 X6M Monte Carlo Blue Join Date: Jul 2008 Location: Los Angeles Coast iTrader: (0)	For those interested in Acceleration... I really love the way the X6M is able to accelerate from a dead stop. It really can surprise almost anyone next to you. No hint of tire slip, and an immediate surge forward that is unusual for the weight of the vehicle. The M gets the same Final Drive ratio as the 35i which is 3.91. The 50i gets a ratio of 3.64. The 2011 8 speed transmission will improve the mileage and efficiency but it may not accelerate quite as well. Shifting gears takes time and will probably reduce the acceleration rates. Please see below: 2008-2010 50i: 1st gear ratio 4.17 x Final drive ratio 3.64 equals effective gear ratio of 15.1788. 2010 X6M and 2008-2010 35i 1st gear ratio 4.17 x Final drive ratio 3.91 equals effective gear ratio of 16.3047. 2011 35i and 50i with 8 speed transmission: 1st gear ratio 4.71 x Final drive ratio 3.15 equals effective gear ratio of 14.8365. If someone would swap the 8 speed into an M (if it could handle the torque) you would end up with a Final drive ratio of 18.4161 in first gear! That could potentially break things and would be a very short 1st gear. They would have to reduce the axle ratio to use this transmission, possibly to the 3.64 in the 50i which would result in a final drive ratio of 17.1444, higher than the current M. Will the 8 speed end up in the M? I rather doubt it at this point. Overall these are very stout numbers for all of the X6's and explains some of the quick off the line acceleration from these vehicles.
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06-28-2010, 06:57 AM	#2
flipside99 Second Lieutenant 74 Rep 225 Posts Drives: iX M60 Join Date: Jun 2010 Location: New York Metro iTrader: (0)	BMW claims that the new 8-speed shaves .2 seconds off the 0-60 times in both the 35i and the 50i.
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06-30-2010, 06:57 AM	#3
kmg99 New Member 1 Rep 5 Posts Drives: X6 M Join Date: Jun 2010 Location: Chicago, IL iTrader: (0)	Don't forget the torque convertor multiplication at stall speed in your calculation as it can have a significant effect on torque multiplication and vehicle performance. The 8-speed would likely be marginally quicker; although with the X6M's extremely wide torque band the difference will be very small.
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07-01-2010, 12:17 AM	#4
LANDLORD Turbo Engines are Fun 24 Rep 252 Posts Drives: 2010 X6M Monte Carlo Blue Join Date: Jul 2008 Location: Los Angeles Coast iTrader: (0)	Good Point, I have been wondering about the torque converter, and if the computer can change the performance of the torque converter at all. It seems to reason, that say during launch mode, the computer may be able to adjust the torque converter's response. It seems as if in sport mode the torque converter does react slightly differently. I wish I knew a BMW engineer who could really divulge all of the abilities of the computers control of the vehicle.
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