Group B - Groups N, A and B

Groups N, A and B

The FISA decided to separate the rally cars into three classes: Group N (production cars), Group A (modified production cars), and Group B (modified sport cars). These groups were introduced in 1982.

Group N and Group A cars were the same cars with different amounts of race preparation allowed (in Group N almost no modifications, in Group A significant modifications). The cars had to have four seats (although the minimum size of the rear seats was small enough that some 2+2 cars could qualify) and be produced in large numbers. This was 5000 cars/year between 1982 and 1991. It later changed to 2500 cars/year if the version being homologated was derived from a mass-market car (25000 cars/year for all versions).

Group B was conceived when the FISA found that numerous car manufacturers wanted to compete in rallying; witnessing the successes of the Stratos and the Quattro, they felt that having cars with mid-engine and RWD or 4WD was the way to go. They found that their RWD models had been gradually replaced by their FWD counterparts, lessening their chance of winning. By reducing the homologation minimum from 400 (in Group 4) to 200, manufacturers had a chance.

Group B cars could be two-seaters and the minimum production was 200 cars/year. Manufacturers were allowed to homologate an evolution each year by producing 20 cars of that evolution. The cars entered in the races were further modified (same modifications allowed as in Group A). Group B could in theory be used to homologate production sport cars, which could not be homologated in Group N or A, because they did not have four seats or were not produced in large enough numbers (e.g. cars like the Ferrari 308, the Porsche 911, etc.). The designation used in the regulations ("Sports Grand Touring Cars") shows this intention.

The big manufacturers, however, used them in a different way: they designed a rally car, of which 20 were produced and designated the evolution model, and then built a limited series of 200 street cars for homologation. (Similar things have been done before in Group 4, for instance the Lancia Stratos.) In some cases these cars were sold at a loss and journalists reviewing them now acknowledge that their development was not quite finished.

In each group there were classes based on engine displacement (with a 1.4 equivalence factor for forced induction engines). Each class had different weight limits, maximum tyre sizes, etc. The most important classes for Group B were the 3000 cc class (2142.8 cc with turbo or supercharger), 960 kg minimum weight (Audi Quattro, Lancia 037) and 2500 cc (1785 cc), 890 kg (Peugeot 205 T16, Lancia Delta S4).

The original Renault 5 Turbo had a 1.4 L engine so it was in the 2000 cc class. The Ferrari 288 GTO and the Porsche 959 were in the 4000 cc (2857 cc), 1100 kg class, which would have probably become the normal class for track racing if Group B had seen much use there. Otherwise they existed for old Group 4 cars which competed until 1985.

Classes in Group B:

Audi was in the 3000 cc class because the displacement of the street car happened to be in that class, and as a car derived from the street version, it would have been difficult to reach the minimum weight needed. For the 037 Lancia decided that the lower class might be too light and consequently too fragile for gravel rallies, and they happened to have a good 2000 cc engine.

When these rules were decided it was felt that these displacement restrictions would be enough to control power, but in the early and mid-80s engineers learnt how to extract almost unlimited amounts of power from turbo engines (the same thing was happening in F1). Nowadays the power of turbo engines is limited by mandating a restrictor in the intake (in World Rally Car, Group A and Group N).