Figure 1
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Lowering |
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It reduces weight transfer |
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If you ask
the average enthusiast "Why is it good to lower a car?" you might get the
following answer:
"Because it lowers the center of gravity." Well that is certainly correct. But if you continue and ask "Why is a lower center of gravity beneficial to handling?" you might get a blank stare. But let's assume that you get the correct answer: "A lower center of gravity is good because it reduces weight transfer during cornering." Then you might ask "What's so good about reducing weight transfer?" Possibly at this point the best answer you might get is "Reducing weight transfer just makes the car corner better." Again, this is a correct answer, but it is not very instructive. A better answer would be that "Reducing weight transfer is good because a pair of tires can create the greatest lateral grip when the weight they carry is evenly distributed." When a car corners, a centripetal force acts on its center of gravity (CG). This centripetal force acts as a lever arm to transfer some of the vehicle weight from the inside tires to the outside tires. |
Figure 1
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This figure shows the forces involved
in creating weight transfer. The car is cornering towards the left
and some of its weight has been transferred to the right-side tires.
Since the outside tires are loaded more heavily, they can create a greater lateral grip then the inside tires. But the key point to remember is that the tires would generate the most grip if they were evenly loaded (N1 = N2). This is due to "load sensitivity". Tires do not create friction like blocks of wood on a smooth surface (or like brake pads on a rotor). During cornering, the loss of grip experienced by the inside tires is not made up for by the increase in grip of the outside tires. Thus the overall cornering power of a pair of tires is reduced due to weight transfer. |
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So we might want to reduce the weight transfer that occurs during cornering.
Short of actually reducing the overall weight of the car...
There are only two ways that you can make a significant reduction in weight transfer: | ||||
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| This is why all purpose built race cars are low and wide. |
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