Racing car Suspension
From the early 1960s to the present day virtually all serious racing cars have used the classic double wishbone suspension arrangement or a close variation of that.
This type of suspension has the advantages of light weight, impressive strength and a well-controlled ride. The purpose of a F1 Car's (and any car) suspension is to keep all four wheels glued to the track despite these aberrations in the pavement. A racing car's suspension also has to be lightweight, compact and, in any serious open wheel racing class, aerodynamically well designed. F1 cars operate substantially similar suspension front and rear,the packaging varies each end but the main components are the same.
The front suspension consists of two triangular supports (wishbones) that mount to the front hubs. The springs and shocks, as well as the equivalent of the anti-roll bar, are all mounted inside nose cone, just in front of the driver legs.
The rear suspension is similar to the front by design. The main differences are the lack of the steering mechanism, the addition of the drive shaft and the greater weight that the rear suspension must carry. The springs and shocks follow an arrangement similar to the front suspension, but they are larger and fold alongside the gearbox.
Double wishbones control the wheels attitude and from the outer end of the wishbone, a rod controls a rocker that then activates the various elements that control the suspensions compliance. Firstly the springs are in the form of torsion bars, these are like straightened coil springs and their resistance to twist provides the springing medium to support the cars mass. Dampers, one for each wheel, control the movement of the wheel as it raises and falls (bump and droop). The antiroll bar controls the amount of weight transfer from one side of the car to the other. Lastly the third spring, also known as a heave damper control the pitch movement (both wheel bump or droop simultaneously) This is especially important to prevent the downforce load pressing the car against the track and bottoming the car on the ground at high speed. Teams may also fit an inerter in this position to offset the uncontrolled bounce of the tires having an effect on the chassis.
The beauty of double wishbone suspension arrangement is that by carefully design of the pivot points (points on which suspension arms rotate) and arm lengths, the camber of the wheel can be maintained close to the optimum even while the body rolls during cornering.
Not only that but the roll centre - a term for the abstract point around which the car rolls when cornering - can be held consistent, helping to race with the car with stable handling characteristics. Then there are ways of further refining the handling characteristics by angling the axes of the wishbones in various ways. For instance wheel toe-in, camber angle and castor angle can be made to vary with body roll to enhance steering feel, or upward (bound) suspension deflection can be made to act against the forward weight transfer under braking to oppose front end dip. This is known as anti-dive and a similar arrangement in reverse, known as anti-squat, can be applied at the rear.
In recent years, suspension members have been streamlined into an aerofoil shape. According to the rules however, they are not allowed to produce downforce, and are simply shaped that way to reduce drag, and to keep the flow heading for the sidepods relatively undisturbed. The suspension arms are a good example, as they are often made in a shape of a wing, although the upper surface must be identical to the lower surface. This is done to reduce the drag on the suspension arms as the car travels through the air at high speed. Diagram A, represents an unstreamlined suspension arm, and the lower one, B, a suspension arm with an aerodynamic covering. Both have roughly the same cross sectional area, but the B has a drag force ten times less than A.
