# Friction Coefficient, F1 corners

1. Nov 10, 2014

### al_garnett

I am using the tyre friction equation Fc=mu*Fnormal to calculate the downforce required for each corner of the Gilles Villeneuve circuit in Canada.

Fnormal composes of the downforce and weight of the car.

mu has a maximum value of 1.7, however this value will vary from corner to corner right?

this is resulting in negative values for downforce in some corners.

Does anyone know a way of calculating the tyre friction coefficient for each corner without needing the Fnormal force?

All of my calculations are on the attached excel spreadsheet.

#### Attached Files:

• ###### Force Calculations Using Lateral Acceleration.xlsx
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2. Nov 11, 2014

### billy_joule

Could you explain a mechanism that the friction coefficient could change from corner to corner?
Where did you get your value of 1.7?

It sounds like you are assuming the car is at the limit of it's lateral grip for every corner, through the entire corner.
Lateral grip is decreased during braking or acceleration.
Downforce is a function of forward velocity.
Racecars do not follow a circular arc around corners or have constant speed.

Carrol Smiths "Tune to win' is a great, easy reading book that'll clear up some misconceptions.

3. Nov 20, 2014

### Dr.D

Remember that the friction equation you are using says,

Ffriction <= mu * Fnormal

The friction force can certainly be less than the product mu * Fnormal.