We all love Sports Cars, or the idea of them at least. Probably something to do with the Sheer Speed and Control, or Feeling Superior to the other cars on the road! The backbone supporting all these boundary-pushing numbers is stability on the road. Many of us will know that to achieve this, the car is lowered
and given a larger Wheelbase and Track, but few will know exactly why this is done:
The main Physical Concept at play here is Centre of Gravity, which is defined as “The point in a Body through which its entire mass is focused or appears to act” or, in simpler terms, the point at which the body would be perfectly balanced. The amount of movement of this point when a force is applied to the body is what helps to determine the stability of a vehicle, to elaborate: if this point moves less, the mass of the body goes less awry, and it is less likely to topple (Yes, Topple is a Technical Term).
All it takes is a little visualization (Of the manner in which a car tilts when cornering) to realize that a Lower Centre of Gravity Point will move less and lead to greater stability. There are a variety of ways to achieve this, where recurring concepts include lowering the stance of the vehicle and spreading its weight over a large area, rather than ‘stacking’ it. The most common techniques are:
Lowering suspension and Shorter Body: Both of these aim to bring the extreme point of mass of the body in the vertical direction closer to the ground to lower the center of gravity.
Lower mounted engine: The engine is where the majority of the weight of a car is focused. Hence,
the lower mounting of the engine creates a significant difference in stability. Note: This is the main advantage of a Horizontally-Opposed Boxer Engine.
Wider Track and Longer Wheelbase: This spreads the weight of the car over a larger area, reducing the displacement differentials through the center point due to the rigidity of the body and suspension.
Larger Tires: Although the primary purpose for these is grip, the larger contact patch with the road can help to exploit the benefits of a well weight-distributed body.
Anti-Roll Bars: This is one that only affects the Stability in cases where there is a large rotational/tilt displacement of the Centre of Gravity when cornering hard, by helping the body to stay fairly level.
This said, even if a few of these are well followed on a tall vehicle, it can be amazingly stable! Perfectly depicted by Double decker buses, which have an extremely flat and low powertrain layout with added ballast under the floor to keep them grounded!
- Personal Experience
- Physics Education
PS. This is my apology for the late posting of my article of RFID tagging.