From Wikipedia, the free encyclopedia

Subaru Impreza WRC

World Rally Car is a term used to describe the racing automobiles built to the specification set by the FIA and used to compete in the outright class of the World Rally Championship (WRC).

Technical regulations mandate that World Rally Cars must be built upon a production car with a minimum of 2500 units, based on a pre-existing Group A model, to which a number of modifications may be added, including but not limited to increasing (or decreasing) engine capacity to 2.0 litres, adding a turbocharger, four wheel drive, active differential, sequential gearbox and aerodynamic parts, and the Anti-Lag System on turbocharged engines. The cars must also have a minimum weight of 1230kg.

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, as evidenced from cars such the Peugeot 206 and 307, Citroën Xsara, or the Skoda Fabia, which have no road car with a turbocharged petrol engine or four wheel drive.

To limit power, all forced inducted (turbo) cars are fitted with a 34 mm diameter air restrictor before the turbocharger inlet, this limits the air flow to about 10 cubic meters per minute. The restrictor therefore limits the power output to about 330-340 hp (officially 300 hp - which was correct about 10 years ago). Because of that, engine development is more focused on producing an engine with a very wide power curve rather than a high peak power output. This means that a power ouput in excess of 300 hp is available all the way from 3000 rpm to the red line of 7500 rpm 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 ^[1]. The cars are further modified for greater rigidity with rollcage and other chassis strengthening measures. Before each rally, the competing cars are fitted with suspension and tyres along with different differential settings to suit the conditions of the many stages, which may take place on asphalt roads, gravel and dirt roads of varying consistency, and even frozen snow-covered roads on some rallies held in relatively cold climates.

• Citroën C4 WRC (2007-)
• Citroën Xsara WRC (2001-2006)
• Ford Escort WRC (1997-1998)
• Ford Focus WRC (1999-)
• Hyundai Accent WRC (2000-2003)
• Mitsubishi Lancer Evolution WRC (1997-2003)
• Mitsubishi Lancer WRC (2004-2005)
• Peugeot 206 WRC (1999-2003)
• Peugeot 307 WRC (2004-2005)
• Seat Cordoba WRC (1998-2000)
• Skoda Fabia WRC (2003-)
• Skoda Octavia WRC (1999-2003)
• Subaru Impreza WRC (1997-)
• Suzuki SX4 WRC (2007-)
• Toyota Corolla WRC (1997-1999)

• Photos of World Rally Cars 2006 in Monaco

1. ^ "Subaru Rally Engine - Developing a World Rally Car power plant", page 23-30, Race Engine Technology, issue 005, 2004