Downforce, banked turns, and friction

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Discussion Overview

The discussion revolves around the role of aerodynamic downforce in motorsports, particularly in relation to banked turns. Participants explore how downforce affects the maximum velocity a car can achieve while navigating a turn, considering factors such as friction and normal force. The conversation includes theoretical derivations and implications of including downforce in calculations.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants suggest that aerodynamic downforce is crucial for speed in motorsports, especially in turns, but question its significance in banked turns where normal force is often omitted in calculations.
  • Others argue that downforce is only relevant when friction is the limiting factor, noting that increased downforce can lead to greater drag, potentially reducing top speed and acceleration on straight paths.
  • One participant proposes that including downforce in the formula for maximum velocity around a banked turn would alter the derivation, as downforce increases normal force without affecting the required centripetal force.
  • A participant shares a link to a diagram, seeking validation of the non-downforce variant of the formula presented.

Areas of Agreement / Disagreement

Participants express differing views on the importance of aerodynamic downforce in banked turns, with no consensus reached on its overall impact or the implications for the formulas used in calculations.

Contextual Notes

There are unresolved assumptions regarding the relationship between downforce, normal force, and centripetal force in the context of banked turns. The discussion highlights the complexity of these interactions without providing definitive resolutions.

jonesto95
In motorsports, everyone talks about getting the greatest amount of aerodynamic downforce on a car in order to get the most speed.

However, every derivation I see for a formula regarding the maximum velocity a car can take around a banked turn, with friction, ignoring aero downforce, removes the normal force. This makes me think that aerodynamic downforce isn't important when in a banked turn, but that doesn't make sense to me at all, since it can be important on 0° and 90°+ turns.

If I were to consider downforce, would this formula change at all? And if so, what would change?
 
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jonesto95 said:
In motorsports, everyone talks about getting the greatest amount of aerodynamic downforce on a car in order to get the most speed.

That is only true when friction is the limiting force. Downforce and it's associated increase in drag generally reduce top speed & acceleration in a straight line.

However, every derivation I see for a formula regarding the maximum velocity a car can take around a banked turn, with friction, ignoring aero downforce, removes the normal force. This makes me think that aerodynamic downforce isn't important when in a banked turn, but that doesn't make sense to me at all, since it can be important on 0° and 90°+ turns.
If I were to consider downforce, would this formula change at all? And if so, what would change?

Yes the formula would change. Try it out and see what you get.
 
Is this all valid? Above the line is the non-downforce variant. I can take it from here if it's good.

http://imgur.com/U1HBWYJ
 
jonesto95 said:
In motorsports, everyone talks about getting the greatest amount of aerodynamic downforce on a car in order to get the most speed.

However, every derivation I see for a formula regarding the maximum velocity a car can take around a banked turn, with friction, ignoring aero downforce, removes the normal force. This makes me think that aerodynamic downforce isn't important when in a banked turn, but that doesn't make sense to me at all, since it can be important on 0° and 90°+ turns.

If I were to consider downforce, would this formula change at all? And if so, what would change?

The reason that normal force is removed in most derivations of the speed a car can take around a corner is that the centripetal/centrifugal (take your pick) force to go around a corner at a given speed is proportional to mass, and the normal force is also proportional to speed, so they cancel out. Downforce increases the normal force without increasing the required centripetal force, so it will not cancel out in the derivation (and, in fact, it will also make it so the mass no longer cancels out as well).
 

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