Quote:
Originally Posted by M4TW
Thanks for saving me the work of digging up your calculations. However, how would you convert 14.5 lbs of unsprung weight to sprung weight? What factor would be appropriate? 1:1, 1:2, 1:4, 1:10? Unsprung weight savings should be magnified in the handling characteristics of the car no?
Further, there was a big ballyhoo about the 40% reduction in the rotating mass of the drive shaft improveing engine responsiveness. Wouldn't a further reduction of 27.5 lbs add to that? Or do we only use half of that representing the back wheels?
I'm not being rhetorical here. I have a genuine interest in your reply.
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There is no conversion for unsprung to sprung weight that I know of. The improved handling provided by lower unsprung weight does not translate back to the total weight of the car per se.
You might have missed the
link I provided in my previous reply. Some of the answers you seek are there.
As for the driveshaft, the impact of the reduced inertia on equivalent mass is amplified by the square of the final drive ratio. So inertia reduction on the driveshaft has ~11 times more impact than inertia reduction on the wheels/tires on the F8X. But since the diameter of the driveshaft is fairly small, reducing the weight does not have huge impact on inertia. The mass factor of the driveshaft is about 1.1, which is less than the wheels and tires. IMO, the increased responsiveness provided by the CF driveshaft comes from both, the increased stiffness and the reduced weight.