Calculations

Torque

M = 550;        % Car mass (kg)

r = 0.27;       % Wheel radius (m)

Cr = 0.0055;    % Rolling resistance coefficient - Winning Solar Car pg 18

A = 2.2;        % Frontal area (m^2)

Cd = 0.18;      % Drag coefficient - from Ron's preliminary CFD findings

rho = 1.225;    % Density of air (kg/m^3)

g = 9.81;       % Acceleration of gravity (m/s^2)

Plotting the motor toque with the above parameters at various speeds, accelerations and angles of incline results in the following:

Note: these plots assume 0 headwind and no wheel slipping.

In order to travel 120km/hr we need to spin at 1180rpm (1km/hr ≃ 10rpm)