Unbelievable levels of power, excitement, and controversy. The Group B class had it all. We take a look at some of the most famous rallying cars in the world. They were ultra powerful cars that were so fast that they had to shut it down because it was too dangerous. If you have a related fact that you would like to have mentioned, make sure to leave a comment below or visit my contact page.

The early ’80s saw major change sweep through international motorsport, with new Group N, A, B and C rules replacing the Group 1-6 regulations that had held sway for decades. Suddenly teams and manufacturers faced new challenges – and new opportunities. Group N and A cars had to be built in 5000 units or more, with the former in particular allowing very little scope for performance modification and the cars having to adhere to certain interior measurements and have at least four seats.  

Group B was very different. It was intended as a replacement for Group 4 and 5. The plan was that 200 examples had to be built over a 12-month period, and this time just two seats were required. Teams could apply Group A-style modifications to the cars to bring them up to competition specification, the idea being to allow and encourage more exotic, low-volume machinery. This way it would be easier for everyone to build a high-performance rally car.

Also, a manufacturer could introduce a new evolution model every 12 months, but if it wanted to change anything fundamental a further 200 cars would have to be built as an entirely new homologation model.

Over at Ford Motorsport, chief rally engineer John Wheeler remembers the pain of producing homologation cars. ‘Building 400 cars for Group 4 was a massive task for a manufacturer,’ he says. ‘The cost of design and development was huge – mega-millions for the entire project. It’s only when you get down to 20-or-so cars that you can look to build them in racing workshops.’ 

What a manufacturer could build was unfathomably relaxed by the standards of modern motorsport regulations, with their endless pages of prescriptive rules, air restrictors, and common-to-all parts. Essentially, there was a matrix of displacement, weight and wheel width, into which every car could fit. The regs ran from 1 liter up to 5 liters-plus, but the key categories for rallying fitted between 2 and 4 liters. Cars with engines up to 2-liter displacement had a minimum weight limit of 820kg (the Renault 5 turbo was in this category), rising to 4-liter machines that could weigh no less than 1100kg. An equivalent factor of 1.4 was applied to engines with forced induction, so, for example, the up-to-2.5-liter class meant a turbocharged engine of no more than 1.785 liters and a weight of 890kg. The Peugeot 205 T16 and Lancia Delta S4 fell into that particular category, while the turbocharged 2121cc Audi Quattro and naturally aspirated 3-litre Metro 6R4 both fell into the 3-liter class. The 4-liter class included the Porsche 959 and Ferrari 288 GTO the Ferrari in particular intended for Group B circuit racing – a form of racing that never came to existence. 

‘No one had been thinking four-wheel drive when Audi came along with the Quattro,’ says Austin Rover man Davenport. ‘Up to that point, four-wheel-drive cars were perceived as useless.’ 

Lancia had its 037, and Ford was working on a new rear-wheel-drive Escort that did at least use turbocharging – the ill-fated RS1700T – yet history now shows us it was wasting its time. Four-wheel drive changed everything, slashed seconds and even minutes off stage times, and opened the door to far greater useable horsepower. After all, there was only so much power that could be deployed through the rear wheels on a loose-surface stage, even if you could generate it in the first place. 

Nevertheless, it was also obvious to the engineers of rival teams that Audi’s approach was fundamentally flawed. What was required was much more favourable weight distribution. Both Ford and Austin Rover experimented with front-mid-engine layouts but found packaging an engine and four-wheel-drive running gear impossible. Both then put the engine in the middle, the Ford RS200 featuring the gearbox up front for arguably the most benign balance in a Group B car. 

More than anything else, it’s the raw power that defines the Group B era. By 1986 there was a 500 club: the E2 S1 Quattro with at least 550bhp, maybe more; the turbocharged and supercharged Delta S4 with the incredible response as well as immense power; and the Evo 2 T16, at least when fitted with an F1-spec turbocharger, as the team had tried.  

And just imagine what might have come later. For 1987 Ford planned to introduce the first evolution of the RS200, having bucked the trend by rallying the original ‘200-build’ car in its first year. The ‘Evo’ put right one of the original car’s main weaknesses: 444bhp in 1986 just simply wasn’t enough. The larger 2.1-liter BDT engine moved the car to the optimum point in its displacement/weight class and would have given the RS200 a reliable 650bhp from the start of the season. 

On 2 May 1986, Lancia’s superstar driver, Henri Toivonen, and his navigator, Sergio Cresto, were leading the Tour de Corse rally with ease. Toivonen was the best driver of Group B: young, charismatic, fast and fearless. He was the only one of Lancia’s brilliant driving team to truly tame the ferocious yet ungainly Delta S4, a car that in many ways summed up everything that was good and bad about Group B rallying. 

Exactly why Toivonen and Cresto left the road on a seemingly simple corner has never been established, but the Lancia appeared neither to brake nor turn before it tumbled down the hillside, bursting into a fireball almost on impact with the trees. The S4 had much in common with a sports-prototype racing car from the 1960s, with a simple tubular spaceframe chassis and the crew sat on fuel tanks with minimal protection; the pairing didn’t stand a chance. Group B was immediately banned from the end of the year, and its – safer – intended Group S replacement along with it. 

Toxic, extremely flammable fuel; rules that allowed freedom but stipulated little on safety; spectators who stood where they liked in their thousands; rallies many times longer than those of today… Many things contributed to the demise of Group B. One thing is certain: we’ll not see anything like it again.