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Group B |
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Brief history background
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Group B |
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Some history
Group A cars have existed for a long time (at least 20 years although the term Group A is more recent) but were eclipsed by the monstrous group B cars until 1986 when the latter were abandoned mainly due to Henri Toivonen's death in Corsica. Group B cars at the time had to be produced to 250 samples to get the FIA homologation and be able to race. The limited production allowed manufacturers to produce cars whose cost would be prohibitive if the production numbers were higher.
Group B cars had in common:
Their most known representatives were:
Lancia 037 (a.k.a. rally, centrally mounted engine, rear wheel drive),
Lancia S4 (4x4, centrally mounted engine). In rallying, the savagely powerful S4 Group B cars were nearing their demise, not least because they were simply just too powerful with some 400bhp on tap. The S4's 400bhp would whip it up to 60mph in under three seconds. Although the 4-valve per cylinder engine had a humble capacity of only 1800cc, the 400 horses would whip the light bodied S4 up to 60mph in under three seconds! The detuned road versions, which had 250Bhp on tap, would do it in under six. Impressive. All this power was achieved by using a supercharger that was proportional to the rotational engine speed, and a turbo that was more or less proportional to the square of the speed. Sounds complicated? It was. This configuration allowed the supercharger to produce substantially more low-speed boost than the turbo, although the latter would come into its own at higher speeds. For this to be effective, a centrifugal clutch that disengaged the drive at 4000rpm was fitted to the the crankshaft drive wheel. The turbo would then kick in. This genius subsequently produced plenty of low-down torque and huge dollops of power at high engine speeds, although later on, the single turbo was replaced by two smaller turbos. This change brought the turbos on song at around 3500rpm.
Tragically, though, the world of rallying lost the spectacular driving style of Henri Toivonen when he flipped his S4 over the edge; this horrendous accident helped convince the sport's governing body that changes had to be made.
The cars had 600+ Bhp engines and a weight around a ton. You realize the danger the drivers and the spectators were facing. The FIA decided to ban GroupB cars in rallying since 1986. Some evolutions of old Group B cars are still being used in rallycross events and some in the European Mountain championship. If you're a fan and lucky enough you might still see one in action. In 1996, for instance, I saw a Lancia Delta S4 racing in Switzerland, what a thrill!
To get an idea of the performance of Group B cars I'll mention that in the 1986 season Henri Toivonen made some laps around the Estoril circuit, during the Portuguese rally, the fastest of which would have qualified him in the sixth position of the F1 Grand Prix that same season...Toivonen was using the Lancia Delta S4 and was accompanied by his usual co-driver Sergio Cresto. Keep in mind, however, that current GroupA cars are yet faster than GroupB cars used to be.
Note that the engine used in the Metro 6R4, a 3.5 lt. V6 was used to power the famous Jaguar XJ220 in the early 90s (it was fitted with turbos in the XJ220).
