Group B
Group B regulations produced some of the fastest rally cars ever built.
Group B was a set of regulations for grand touring cars in sports car racing and rallying, created by the FIA in 1982. While these cars could compete in a GT class of the World Sportscar Championship alongside the faster Group C prototypes, they are best known for their role in international rallying. From 1982 to 1986, Group B served as the top class in the World Rally Championship, as well as in regional and national rally events. The rules led to the creation of some of the fastest, most powerful, and most technically advanced rally cars ever made, and this period is widely called the golden era of rallying.
However, a series of serious and fatal crashes occurred, driven by ongoing concerns about the unchecked growth of the cars' performance, the rally routes, and poor crowd control. After Henri Toivonen and his co-driver Sergio Cresto died in the 1986 Tour de Corse, the FIA banned Group B from the WRC starting the next season. The organization also abandoned its plans to introduce Group S, instead making Group A the top rally class, with engine limits of 2,000 cc and 300 hp.
In the years that followed, former Group B rally cars found a place in the European Rallycross Championship until that series dropped them in 1993. By 1991, the World Sportscar Championship had moved on from both Group B and Group C, and the GT championships of the 1990s preferred other classes, such as the new GT1. The last Group B cars were homologated in 1993, though the FIA allowed national championships and domestic racing to use them until as late as 2011.
In 1982, FISA restructured the production car categories in Appendix J of the International Sporting Code into three new groups. The old Group 1 and Group 2 were replaced by Group N and Group A, for standard and modified production touring cars respectively. These cars needed four seats (though the rear seats could be small enough for some 2+2 models) and high production numbers: 5,000 units in 12 months from 1982 to 1992, then 2,500 from 1993 onward.
Group B was for GT cars with at least two seats, redefined as sports grand touring cars in 1986. It combined and replaced Group 3 and Group 4, two grand touring groups used in rallying, and the production-based Group 5 silhouette cars used in circuit racing. Group 5 had never been allowed in the World Rally Championship for Manufacturers.
- Introduced
- 1982
- Governing body
- Fédération Internationale de l'Automobile (FIA)
- Homologation minimum
- 200 units
- Forced induction equivalence
- 1.4 times actual engine capacity
- Top class in wrc
- 1982–1986
- Ban from wrc
- 1986
- Last homologated
- 1993
Lore & Background
Group B replaced Group 3 and Group 4 in rallying, as well as the production-derived Group 5 silhouette cars used in circuit racing. The homologation requirement of 200 cars—4% of what some other groups required—made motorsport more accessible for manufacturers. 'Evolutions' could be included within the original homologation by producing 20 of the evolved cars rather than 200, leading to rare 'homologation specials' built only to satisfy the quota. Existing cars from Groups 2, 3, and 4 could be transferred to Group B. The regulations placed few restrictions on technology, design, or materials, allowing fiberglass bodywork, space frame chassis, and mid-engine layouts. Weight and engine displacement limits were the primary means of controlling speed, with no restrictions on boost, so power output increased from around 250 hp in 1981 to over 500 hp by 1986. Notable classes included the 3,000 cc class (960 kg minimum weight) for cars like the Audi Quattro and Lancia 037, and the 2,500 cc class (890 kg) for the Peugeot 205 T16 and Lancia Delta S4. The Ferrari 288 GTO and Porsche 959 were in the 4,000 cc class (1,100 kg).
Reader's Guide
A series of major and fatal accidents amid concerns over unchecked performance, rally itineraries, and crowd control led to the FIA banning Group B from the WRC after the 1986 Tour de Corse, where Henri Toivonen and Sergio Cresto died. The FIA dropped plans to introduce Group S and designated Group A as the top rally class with engine limits of 2,000 cc and 300 hp. After the ban, ex-rally Group B cars found a niche in the European Rallycross Championship until 1993. The World Sportscar Championship had moved on from Group B and C by 1991, and GT championships formed in the 1990s preferred other classes such as GT1. The last Group B cars were homologated in 1993, though the FIA made provisions for national championships until 2011. The regulations' low production requirement encouraged manufacturers to design specialized rear-wheel-drive or four-wheel-drive homologation specials without the financial commitment of large-scale production. Turbocharged engines, not yet common in road cars, were pushed to extraordinary power levels; some manufacturers used Formula One-derived antilag systems or twincharging. Today, power output of turbo engines is limited via intake restrictors, and each class in the Groups Rally hierarchy has an explicit weight/power ratio limit.
Did You Know?
- Group B homologation required only 200 cars, 4% of the requirement for Groups N and A.
- Evolutions could be homologated by producing just 20 cars rather than 200.
- The forced induction equivalence factor was 1.4 times actual engine capacity.
- The last Group B cars were homologated in 1993, with national provisions until 2011.
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