Unsprung weight
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Unsprung weight
In another thread I was told that there is a big difference in tyres weights. I saw on this website, www.edgeracing.com that there can be a difference of up to 5lb, which is quite a lot. Now for my question. What influence does the unsprung weight of the car has on say, performance handling and the like? Also, is there a direct correlation between u/s weight and performance as in 1:1 or 1:2 or something like that? All info would be greatly appreciated.
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From: Atlanta, GA
The tuner magazines have discussed this and agree that unsprung weight has more significant effects than sprung weight. Depending on the source, unsprung weight has 3 to 7 times more effect than sprung weight, meaning adding 5 lbs to each tire is like adding as much as 140 lbs to the interior (if my math is correct). Also, heavier tires mean that the extra weight is added further out from the center of the wheel, and the further out the weight is, the greater the effect will be. So, thanks to the laws of inertia, a heavier tire will take longer to accelerate and brake, as well as be more taxing on the suspension system as it tries to control the heavier assembly in its up and down motions.
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From: Boston/Hartford
he he,
if they are brabus apparently so .
but they look so nice tho
I think the formula is like 3 or 4 but its a little bit less with cars with more torque. Torquey motors such as ours are better at moving weight than high horsepower low torque motors.
Bottom Line is unsprung weight really helps.
if they are brabus apparently so .
but they look so nice tho
I think the formula is like 3 or 4 but its a little bit less with cars with more torque. Torquey motors such as ours are better at moving weight than high horsepower low torque motors.
Bottom Line is unsprung weight really helps.
Last edited by Prasith32; Jun 11, 2004 at 03:34 PM.
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OK, so lemme get this right. Say I save about 5lb at each wheel. That is 20lb. Multiply that by 4 and it gives you 80lb. On a car that weigh approx 3600lb that is not such a big difference right? Or am I missing the point? 
Thanks for the advice anyway. At least now I know what effect unsprung weight has on a car.
Thanks for the advice anyway. At least now I know what effect unsprung weight has on a car.
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From: Atlanta, GA
Originally posted by AMG FANATIC
OK, so lemme get this right. Say I save about 5lb at each wheel. That is 20lb. Multiply that by 4 and it gives you 80lb. On a car that weigh approx 3600lb that is not such a big difference right? Or am I missing the point? Thanks for the advice anyway. At least now I know what effect unsprung weight has on a car.
OK, so lemme get this right. Say I save about 5lb at each wheel. That is 20lb. Multiply that by 4 and it gives you 80lb. On a car that weigh approx 3600lb that is not such a big difference right? Or am I missing the point?
Thanks for the advice anyway. At least now I know what effect unsprung weight has on a car.
It's not important unless you run your car at the track and really want to get the extra performance. For a daily driver, the slight difference in acceleration, braking, handling, and fuel economy isn't that important.
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Originally posted by Micah
It's not important unless you run your car at the track and really want to get the extra performance. For a daily driver, the slight difference in acceleration, braking, handling, and fuel economy isn't that important.
It's not important unless you run your car at the track and really want to get the extra performance. For a daily driver, the slight difference in acceleration, braking, handling, and fuel economy isn't that important.
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Don't underestimate the advantages of unsprung weight reduction. The benefits are not just realized on the track, but are useful in every day driving. Steering feel and turn in characteristics are the most noticable and beneficially change the car's behavior in every situation.
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From: GTA
does that mean that lighter rims are good for track but bad for daily driving in cities?
because i have been thinking why our stock rims are so heavy... did AMG meant to put heavier rims on our AMG cars because they planned our cars for greater durability?
for a price of an Ronal made AMG rim, it cost as much as a, let say BBS or forged light weight rim... i'm sure AMG can put light weight rims on our cars, but they did not...
i see people putting very nice forged rims on their car... but whenever i'm driving on our poorly condition highway... don't think they will survive over those holes...
thats what i have been wondering about...
because i have been thinking why our stock rims are so heavy... did AMG meant to put heavier rims on our AMG cars because they planned our cars for greater durability?
for a price of an Ronal made AMG rim, it cost as much as a, let say BBS or forged light weight rim... i'm sure AMG can put light weight rims on our cars, but they did not...
i see people putting very nice forged rims on their car... but whenever i'm driving on our poorly condition highway... don't think they will survive over those holes...
thats what i have been wondering about...
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Lighter rims are good for any driving situation as long as they are strong enough for their intended environment. Most high quality aftermarket three piece wheels have forged centers, and a few tuners and wheel manufacturers produce high quality one piece forged wheels which are much stronger than the typical cast wheel. The forging process increases their strength and reduces their weight. Unfortunately, forged rims costs more to produce and represent a limited volume on the market. Heavy wheels are not necessarily stronger, although a heavier quality cast wheel will hold up better to pot holes than a lighter cast wheel.
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Originally posted by smgC32
Lighter rims are good for any driving situation as long as they are strong enough for their intended environment. Most high quality aftermarket three piece wheels have forged centers, and a few tuners and wheel manufacturers produce high quality one piece forged wheels which are much stronger than the typical cast wheel. The forging process increases their strength and reduces their weight. Unfortunately, forged rims costs more to produce and represent a limited volume on the market. Heavy wheels are not necessarily stronger, although a heavier quality cast wheel will hold up better to pot holes than a lighter cast wheel.
Lighter rims are good for any driving situation as long as they are strong enough for their intended environment. Most high quality aftermarket three piece wheels have forged centers, and a few tuners and wheel manufacturers produce high quality one piece forged wheels which are much stronger than the typical cast wheel. The forging process increases their strength and reduces their weight. Unfortunately, forged rims costs more to produce and represent a limited volume on the market. Heavy wheels are not necessarily stronger, although a heavier quality cast wheel will hold up better to pot holes than a lighter cast wheel.
