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to side glass treatment, the vehicle ground clearance and the relatively

large vehicle cross-sectional area were considered areas which could be

improved to reduce drag.

Ground clearance, front end treatment and overall vehicle shape

were also important factors in the lift and side force distribution on

the 1969 race car, and thus, had an important effect on handling. The

aerodynamic forces which affect the handling of the 1969 race car are

schematically shown in Figure 3. The directional characteristics o -r h t the

1969 race car are significantly influenced by aerodynamic side forces.

As the car enters a curve, high side forces are produced at the front of

the car. These ide forces tend to make the car oversteer with the

amount of oversteer being directly proportional to the aerodynamic yaw­

ing moment about the center of gravity. The yawing moment is a function

of the total aerodynami U ide force and the distance from the center of

gravity to the center of pressure (this distance is termed the static

margin). The larger the static margin or the highe the aerodynami cn id C D

force, the more the oversteering tendencies. Notice the aerodynamic

ide forces act toward the center of the turning radius or oppose the

inerta forces at the center of gravity. High aerodynami u ide forces

near the center of gravity would be desirable rh O race cars to reduce

the tendency of the car to continue in a straight line or ’’push” as

termed by the drivers.

The static margin in the lift plane is shown in the lower part of

Figure 3 for the 1969 race car. As shown, the 1969 race car generates

large front end lift forces which tend to make the front end feel light

relative to steering response at race speeds. For good handling, it

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