Time for some updates since many happened to the car since my last post
18.03.2011Car's weight without driver + 55% gas :
Front left > 442Kg
Front right > 515Kg
Rear left > 339.5Kg
Rear right > 279Kg
TOTAL > 1575.5Kg
Car's weight + driver + 55% gas :
Front left > 474Kg
Front right > 530Kg
Rear left > 372Kg
Rear right > 288Kg
TOTAL > 1664Kg
The difference between the 2 measurements = 88.5Kg, meaning exactly my weight :
My weight distribution on the 4 wheels :
Front left > 32Kg
Front right > 15Kg
Rear left > 32.5Kg
Rear right > 9Kg
TOTAL > 88.5Kg
It's interesting to notice that on the left side, more of my weight went to the rear wheel than the front one, meaning that either my CG is more towards the rear than the car's CG (hard to believe), either the rear suspension compresses more under the same weight than the front one.
Weight distribution including driver :
Left - right :
Left = 846Kg > 50.84%
Right = 818Kg > 49.16%
Front - rear :
Front = 1004 > 60.34%
Rear = 660Kg > 39.66%
Cross weight :
Front left - Rear right = 762Kg > 45.79%
Front right - Rear left = 902Kg > 54.21%
If the left - right distribution is pretty good, you can clearly see the cross weights are very different. The front right must be heavier due to the subwoofer from the passenger's feet and the rear left might be heavier because the car is lower on that side. This distribution may also be related to the stiff roll-bars.
Car's CG position on a horisontal plane :
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ImageShack.usCar's CG position on a vertical plane :
You first need to weigh the car on a horisontal plane (did that), then you need to raise the rear of the car by say 30-40cm and only weigh the front this time (you need to completely block suspension movement (this is kind of hard to accomplish by me). The position of the CG on the vertical axxis is necessary in order to be compared with the rotation center (CR) of the car wich can be obtained like this > On a transversal section of the car, you draw a line parralel to the lower arm and one perpendicullar to the damper on the upper side of this one. From the point where these 2 intersect, you draw a third line to the point where the middle of the tire meets the road. The intersection of this line with the vertical symmetry axxis of the car gives the CRSe traseaza o dreapta in prelungirea bratelor inferioare si o dreapta perpendiculara pe amortizor plecand din partea de sus a acestuia (la flansa). The closer the CG and CR are, the less body roll you have and the chassis will lean less on both directions !
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