Rotational Weight & Unsprung Weight
03-10-2003 | 11:33 AM
#2
Wannabe yuppie
Joined: Dec 2000
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From: Madison, WI
Unsprung weight and rotational weight affect different things. Unsprung weight is weight that the suspension can't work against, like the control arms, wheel hubs, etc. Rotational weight affects mainly how the car accelerates like a flywheel.
03-10-2003 | 06:19 PM
#4
Joined: Jun 2001
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From: oakland, ca
ive heard of the ratio...but forgot it.
but then i dont think there is a set ratio, since lets say on a rim...1lb on the edge of the rim, wont equal 1lb on a part of the rim closer to the hub. the 1lb on the edge of the rim (lip), will take more engery to move.
but then i dont think there is a set ratio, since lets say on a rim...1lb on the edge of the rim, wont equal 1lb on a part of the rim closer to the hub. the 1lb on the edge of the rim (lip), will take more engery to move.
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03-11-2003 | 07:35 AM
#6
Senior Member
Joined: Jan 2003
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1 lb on wheel is worth 2 lbs anywhere else that isn't rotating. But there's more...
That only works if you take the one pound off at the outside, like the tread or the belts in the tire. Take it off right in the center, & its only worth 1 lb. Anywhere else, like the brake rotor, its worth somewhere in between. That doesn't have anything to do with sprung vs. unsprung weight.
The UNSPRUNG weight is stuff that moves up & down with the wheel. Like the brake rotors, calipers, CV joints, etc. The entire body is SPRUNG weight. Parts of the shocks are sprung, parts are unsprung. You want to have lower unsprung weight, but that's for a different reason.
That only works if you take the one pound off at the outside, like the tread or the belts in the tire. Take it off right in the center, & its only worth 1 lb. Anywhere else, like the brake rotor, its worth somewhere in between. That doesn't have anything to do with sprung vs. unsprung weight.
The UNSPRUNG weight is stuff that moves up & down with the wheel. Like the brake rotors, calipers, CV joints, etc. The entire body is SPRUNG weight. Parts of the shocks are sprung, parts are unsprung. You want to have lower unsprung weight, but that's for a different reason.
03-11-2003 | 11:57 AM
#7
Wannabe yuppie
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From: Madison, WI
Originally posted by InRageD
if you remove 1 lbs. from say the wheel, doesnt the car accelerate like you removed X amount of lbs. from the unsprung body weight?
if you remove 1 lbs. from say the wheel, doesnt the car accelerate like you removed X amount of lbs. from the unsprung body weight?
Unsprung weight is not the whole weight of the car. It's the weight of the suspension components and such which are not part of the car that is held up by the suspension.
Like JimBlake said, SPRUNG weight is the weight of the car. Whether or not the weight is sprung or not though, does not change how much weight the motor has to tow around.