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SKIDPAD
SIMULATION

This spreadsheet is intended to simulate a skidpad test for a RWD car. With this skidpad, however, you're allowed to change the radius at will. And, you can also add banking, if you like.

You can choose between a high performance sedan tire and the NASCAR tire.

Aero drag is taken into consideration by using the force required for a medium sized sedan. It is assumed that the center of pressure is at the same height as the CG.

Oval racers can insert an instantaneous acceleration and then evaluate the effect of asymmetric front spring rates. Also, any combination of corner weights can be used.

The output wheel loads are adjusted for bank angle, but the output radial acceleration is a function of only the speed and turn radius and is NOT adjusted for bank angle.

The rear slip angle is an "equivalent" slip angle, using the friction circle concept to compensate for the increased loads from aero drag and acceleration. Tha absence of calculated slip angles output indicates you have exceeded the capacity of the tires. By gradually reducing the input speed, it is possible to determine the maximum speed for a given configuration.

high performance sedan tire
NASCAR tire

front track =

rear track =

wheelbase =

front roll center height =

rear roll center height =

CG height =

roll stiffness-front sway bar (ft-lb/deg) =

roll stiffness-rear sway bar (ft-lb/deg) =

     

roll stiffness-front springs (ft-lb/deg) =

roll stiffness-rear springs (ft-lb/deg) =

tire rate (lb/in) =

left front spring rate (lb/in) =

right front spring rate (lb/in) =

LF static load (pounds) =

RF static load (pounds) =

     

LR static load (pounds) =

RR static load (pounds) =


turn radius (feet) =

speed (mph) =

angle of banking (degrees) =

forward acceleration (g's) =

ANSWERS:

Front Slip Angle =

Rear Slip Angle =

Radial Acceleration (g's) =

Chassis Roll Angle (degrees)

Percentage of Roll Stiffness at Front

SKIDPAD WHEEL LOADS:

Left Front Right Front

Left Rear Right Rear

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