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Discussion Starter #1
hi all,

i bought a corner weight scale and weighted my car. (2008 Audi S3)
unfortunatelly i learned that i should have removed the sway bars before the weighing.
my first question is how much do the sway bars effect the weighing?

and my second question is; according to my weights can i do an alignment with coilover height adjustment or is it far beyond the limits to compansate.
Is there a limit to adjust corner balance by changing the suspension heights?

LF 464 423 RF
LR 268 272 RR

CROSS 691 48,42%

LEFT 732 51,29%
REAR 540 37,84%

TOTAL 1427

*all weights are in "kg"s.
*driver and a half tank of fuel is included

any advise will be much appreciated..
 

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First, the effect of the sway bar is hard to estimate... theoretically if your left/right ride heights are identical, the sway bar should not be under load, and won't effect the corner weights; if the left/right ride heights are different, the sway bar will increase load on the lower side, decrease load on the higher side. The amount will depend on the stiffness of the bar and the amount of ride height difference. That's why it's best to disconnect the bars when measuring corner weights.

Second, since your total weight is 1427kg, your ideal cross weight is 713.5kg. That's only 22.5kg from your current cross of 691. If you could add approx. 7kg to the LR and 14kg to the RF (decreasing the same amount from the RR and LF), you'd be right on a 50% cross. That sounds attainable if your coilovers have a height adjustment (i.e. adjustable spring perches)

Third, limits to corner weight adjustment will have to do with the combination of ride height and spring settings the car currently has. You could wind up running out of spring perch adjustment at the extreme high and low range of ride height adjustment before you reach the ideal cross weight.
 

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Discussion Starter #3
First, the effect of the sway bar is hard to estimate... theoretically if your left/right ride heights are identical, the sway bar should not be under load, and won't effect the corner weights; if the left/right ride heights are different, the sway bar will increase load on the lower side, decrease load on the higher side. The amount will depend on the stiffness of the bar and the amount of ride height difference. That's why it's best to disconnect the bars when measuring corner weights.

Second, since your total weight is 1427kg, your ideal cross weight is 713.5kg. That's only 22.5kg from your current cross of 691. If you could add approx. 7kg to the LR and 14kg to the RF (decreasing the same amount from the RR and LF), you'd be right on a 50% cross. That sounds attainable if your coilovers have a height adjustment (i.e. adjustable spring perches)

Third, limits to corner weight adjustment will have to do with the combination of ride height and spring settings the car currently has. You could wind up running out of spring perch adjustment at the extreme high and low range of ride height adjustment before you reach the ideal cross weight.
i calculated the same numbers but when it comes to adjustment, i lowered a corner nearly 2cm and only 2kg changed and ride height difference was too much. that was because of the sway bars connected i assume? thats why i thought i am doing something wrong.
 

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Only 2kg? Your sway bar must be quite stiff.
 

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i calculated the same numbers but when it comes to adjustment, i lowered a corner nearly 2cm and only 2kg changed and ride height difference was too much. that was because of the sway bars connected i assume? thats why i thought i am doing something wrong.
I suppose that's possible. After adjusting the heights, have you been "bouncing" the car at each corner to minimize bushing/damper bind before remeasuring corner weights?
 

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Discussion Starter #6
Only 2kg? Your sway bar must be quite stiff.
not exactly 2kg i dont remamber but it was a very small difference 1,5-3 something like that. actually i stripped the car and took out around 10% of the total weight, may be sway bars became stiff for the new weight..

I suppose that's possible. After adjusting the heights, have you been "bouncing" the car at each corner to minimize bushing/damper bind before remeasuring corner weights?
yes we bounced the corners..
 

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Only other thing I can think of, is your left side to right side tire pressures exactly the same? A lower pressure tire will compress more affecting your measurements.
 

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It's usually relatively easy to disconnect one side of the sway bar(s). That's what I'd recommend before proceeding further. Do you happen to have your ride heights, by the way?
 

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Discussion Starter #9
Only other thing I can think of, is your left side to right side tire pressures exactly the same? A lower pressure tire will compress more affecting your measurements.
i dont remember the pressures but they should be exact, i always check them.

It's usually relatively easy to disconnect one side of the sway bar(s). That's what I'd recommend before proceeding further. Do you happen to have your ride heights, by the way?
i will sure disconnect one side next time, i dont have the ride heights i will get them also next time..
 
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