Quote:
Originally posted by Gustav
Is this because the downforce gets so high that the centripetal forces get neglegtible small? Or the forces that pushes the car forward?
Also, I remember that you don't have to steer anything at above some speeds at oval tracks. Why is this? Can someone please enlighten me?
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Luckily, I've managed to pay attention in my Mech Eng BSc classes...
Centripetal forces are the frictional forces that work sideways on a car's tires to keep it travelling in a curve. They The centripetal forces are the exact opposite of the centrifugal forces working on a car (if they arent...the car is sliding out of the corner) and therefore relative to the G-force generated by the car through a corner.
Not having to steer has to do with the banking on the oval track introducing an angle to the gravitational and frictional components. For a car with a given mass and G-force capabilities, on a banked corner there will be a status quo of all forces at a given combination of speed & corner radius, resulting in the lack of steering input Gustav mentions.
Ah yes, now for downforce. The downforce created by a car's shape doesnt really effect this equation directly...however downforce impacts the frictional forces (which are related to the pressure exerted by the car on the underlying road surface, so less downforce signifies less pressure on the road), which in turn impact the centriputal forces.
Downforce is however usually measured while the car is travelling directly into the air stream(so in a straight line) and with some car designs the downforce created at a certain speed may significantly DECREASE when the car is travelling at a slight angle to the air stream (for example in a corner or with a crosswind). Typical examples of this are venturi designs (for example Nissan Skyline) or just plain bad aerodynamic designs (for example Ford Sierra).
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