World Rally Car

World Rally Car is a term used to describe racing automobiles built to the specification set by the FIA, the international motorsports governing body, and used to compete in the outright class of the World Rally Championship (WRC). The WRC specifications were introduced by the FIA in 1997.

Technical regulations mandate that World Rally Cars must be built upon a production car with a minimum production run of 2500 units. A number of modifications may be made to the car, including but not limited to:
 * Engine with displacement of no more than 2.0 litres
 * Turbocharger with Anti-Lag System
 * Four wheel drive
 * Sequential gearbox
 * Aerodynamic parts
 * Weight reduction to a minimum weight of 1230 kg
 * Chassis strengthening for greater rigidity and safety enhancement (rollcage)

However, unlike Group A, manufacturers are no longer required to build "Homologation Specials" in order to meet approval. The base model need not have the characteristics of the WRC car, as evidenced from cars such the Peugeot 206, 307, Citroën Xsara and Škoda Fabia, which have no road car variant with a turbocharged petrol engine or four wheel drive.

To limit power, all forced induction (turbocharged) cars are fitted with a 34 mm diameter air restrictor before the turbocharger inlet, limiting the air flow to about 10 cubic meters per minute. This air flow limits power output of the engine to 300 hp officially, although the latest WRC engines are believed to produce around 330-340 hp in spite of the air restrictor. With this technologically easy to achieve, engine development is focused towards producing an engine with a very wide powerband (or power curve). Generally speaking, a power output in excess of 300 hp is available from 3000 rpm to the 7500 rpm maximum, with a peak of 330-340 hp at around 5500 rpm. At 2000 rpm, which is the idle speed in "stage" mode, the power output is slightly above 200 hp.

Before competing in stages (tracks) of the rally, the competing cars are tailored to the specific conditions of stages ahead. Suspension settings are adjusted, the most appropriate type of tyres are selected and fitted, the four wheel drive system's differential settings are also modified to suit the conditions of the coming stages. Stages may take place on asphalt roads, gravel and dirt roads of varying consistency and frozen snow-covered roads on some rallies held in relatively cold climates.