In most forms of motor racing, be it circuit racing or rallying, there have always been particularly arduous venues causing excessive brake temperatures. On any vehicle the brakes are a safety critical item, and clearly losing part or even all braking power at racing speeds is potentially fatal. Traditionally, rally applications have proved challenging to brake designers because of the extremes of temperature experienced. Such cars generate high stop energies partly because of the relatively high weight of the cars (and high centre of gravity, resulting in considerable weight transfer during a stop) and the use of modern high performance carbon metallic pads. Add to this, marginal cooling and the extremes of abuse provided by left foot braking techniques, and it becomes easy to see why maintaining consistent stopping power throughout a stage can sometimes be a problem.