The group CN designated in the sports car racing at a very specific processing standard of vehicles. Your rules is determined by Article 259 of the International Sporting Code of the FIA. These vehicles are used mainly in mountain championships, such as the EBM and in national sports prototypes Championships.
The vehicles of the group CN be defined as two-seat, open or closed racing car. In contrast to formula cars but all parts of the vehicle must be covered with a body. This can be up to 2 m wide, 4.8 m long and 1.03 m high.
The engines come from the group N, and have a maximum displacement of 3,000 cm ² and a maximum of six cylinders.
In addition to the well-known manufacturers also " self-built constructions " in the program booklets and winners' lists appear. This can actually be manufactured in-house, where the barriers to the fulfillment of the safety requirements are high. Partial but also prefabricated chassis are supplied, and the manufacturer has omitted the mention of his name. It depends on the contractual arrangements between the team and the supplier.
Lesser-known manufacturers build one or two vehicles, and this ride as long as it goes well. After a violent accident, the season may be finished before. Then the driver must wait until a new vehicle is built.