Moment of Inertia Weight - Fact or Urban Legend?

[CanAutM3]

Originally Posted by FogCityM3

BMW's website says CCB system saves nearly 30 lbs vs the regular braking system. How is the savings not ~7+ lbs per corner, or am I missing something?

Total weight is ~14.5lb (3.6lb per corner) according to this reference and rotating mass reduction in 12.5kg (6.9lb per corner) as specified here.

[FogCityM3]

I get the rotating mass reduction but still thought the CCB calipers were lighter, per this multimedia presentation (click on the CCB box) which states that total unsprung weight reduction (rotating and non-rotating masses) is ~30 lbs?

Interestingly the Mov'it CCB system I was looking into was also around a ~30 lbs total unsprung weight reduction (rotating and non rotating masses) vs stock.

http://www.bmw.com/com/en/newvehicle...struction.html

Originally Posted by CanAutM3

Total weight is ~14.5lb (3.6lb per corner) according to this reference and rotating mass reduction in 12.5kg (6.9lb per corner) as specified here.

[CanAutM3]

Originally Posted by FogCityM3

I get the rotating mass reduction but still thought the CCB calipers were lighter, per this multimedia presentation (click on the CCB box) which states that total unsprung weight reduction (rotating and non-rotating masses) is ~30 lbs?

Interestingly the Mov'it CCB system I was looking into was also around a ~30 lbs total unsprung weight reduction (rotating and non rotating masses) vs stock.

http://www.bmw.com/com/en/newvehicle...struction.html

It seems the callipers for the CCB on the F8X are quite heavier than the standard ones. From the interview I referenced above:

Carbon ceramic brakes save 6-7kg (13.2lbs - 15.4lbs) overall. Not as much weight saved as on the F10 M5 with ceramic brakes, but that's because the caliper upgrade is much bigger than in the M5's situation. Here, we're seeing the calipers go from 4 piston front / 2 piston rear on the standard M3/M4 brakes to the 6 piston front / 4 piston rear calipers on the M Carbon Ceramic Brakes.

From the above, I deduce that the CCB callipers are about 13lb heavier.

[FogCityM3]

Wow, weird, all this marketing talk is making things very confusing! Thx.

Originally Posted by CanAutM3

It seems the callipers for the CCB on the F8X are quite heavier than the standard ones. From the interview I referenced above:



From the above, I deduce that the CCB callipers are about 13lb heavier.