Group B Rally

I am going to go through some of the most crazy and iconic Group B Rally cars and try and explain what made them so great through the technology they used to compete in one of the craziest forms of motorsport, ever.

The Group B Rally Technical Rules

I am first going to start by writing about the Rules and Regulations – there were none! At least not regarding car design (including interior and exterior dimensions), material composition of chassis or body work, drivetrain layout, or power output, however there were some general rules – the cabin must not be open rooved and must be able to fit to seats side by side, a minimum weight that was calculated using the engine displacement (forced induction engines counted as 40% bigger displacement than there actual displacement), this was the same with the tyres, there were also some basic safety rules.

MG Metro 6R4

Lets hope the 6R4 had better rust protection than many other British Leyland cars

Lets hope the 6R4 had better rust protection than many other British Leyland cars

The MG Metro 6R4 (6 for 6 cylinders, R for Rally and 4 for 4WD) debuted in 1985 and was based on the MG Metro Road car and was built in partnership with the Williams F1 team. Austin Rover decided to use a naturally aspirated engine instead of the turbocharged inline-4s used by most teams. Both the Honda V6 that later appeared in the Rover 800 and the Rover V8 were considered but Patrick Head (Williams F1 team’s technical director) wanted something smaller and lighter, so a rear-mounted 400bhp aluminium-alloy 3-litre V6 (based on the Cosworth DFV (V8), which also won every non-Ferrari F1 World Championship between 1968 and 1982) was designed and produced allowing the car to reach 60mph in just 3.2 seconds and 100mph in 8.2 seconds. The MG Metro 6R4 took its first win in March 1985 (Gwynedd Rally) but due to the long, punishing WRC events the MG Metro 6R4 often retired (mainly due to engine problems).

Ford RS200

Waiting for the turbo to spool up...

Waiting for the turbo to spool up...

Ford had been part of the WRC since 1976 but they didn’t have the right car to compete against cars like the Audi Quatro in Group B, so they designed the RS200 (The RS1700T was technically first). This was unusual as it was more common for Group B cars to be based off one of the company’s current production models instead of designing a car for Group B then homologating. The Ford RS200 debuted in 1986, but it didn’t have much success in its only season (3rd in the Rally of Sweden was its highest finish) despite it being well balanced and durable, this was mainly due to having low RPM turbo lag and having a lower power to weight ratio than its competitors. The RS200 had a mid-mounted 1803cc (bore – 86.0mm, stroke – 77.62mm) turbocharged (using a Garrett turbo) inline-4 with 444bhp at 8000RPM and 361lb ft of torque at 5500RPM to all four wheels meaning it had a 0-60 in 2.8 seconds. The RS200 had 3 LSDs and a 5 speed manual located at the front for better weight distribution although was worse for efficiency as the power had to be sent forwards the backwards again. The driver could change the torque split, but it was normally split 33% to the front and 67% to the rear. The Ford RS200 had double wish bones, an unassisted steering rack and 285x25mm disc brakes with four-piston callipers on each wheel.

Lancia 037

Does it have enough lights yet?

Does it have enough lights yet?

The Lancia 037 was the last RWD car to win the WRC, in 1983, it was based on the Lancia Montecarlo (or Scorpion in the US). It weighed 960kg and had a mid-mounted 2 litre supercharged inline 4 that made 265hp initially but was increased to 280hp which went through a 5 speed gearbox. The Evolution 2 made 325hp at 8000rpm due to the larger displacement (2.1 litres). A supercharger was chosen over a turbocharger to eliminate turbo lag. Even with the Evolution 2 model the 4WD used by most other manufacturers meant that the Lancia 037 couldn’t win another championship and only manged one win in 1984 and so was replaced by the Delta S4, one of the fastest Group B cars (which was 4WD and a had a turbocharger as well as a supercharger).

Ferrari 288 GTO

It looks like it wants to kill you

It looks like it wants to kill you

The 288 GTO originated from a series of modified 308 GTBs. Michelotto (an independent company that turned Ferrari Road Cars into Race cars) turned four 308 GTBs into cars eligible for Group B rally. One of the cars had a 2 valve V8 producing 288bhp and the other three had 4 valves and produced 310bhp at 8000rpm but they turned out to be 30kg heavier due to steel body panels meaning they were uncompetitive. Ferrari then decided to design a car for Group B (like Ford), this was the 288 GTO. Unfortunately, none of the 272 cars produced ever raced in the WRC because Group B rally had just ended. Although the 288 GTO was based on the 308 GTB there were a lot of differences such as the engine being mounted longitudinally, this increased the wheelbase by 110mm. The engine was also a smaller displacement to the one found in the 308 because Ferrari wanted to turbocharge it and the engine size had to remain below 4L (including the 40% of the displacement added on for forced induction engines). As the displacement of the engine was 3997cc (including the afore mentioned 40%) the car would have had a minimum curb weight of 1100kg and a maximum tire width of 61 cm per side of the car. Ferrari was part of the Fiat Group (so Lancia was meant to do the rallying) meaning the 288 GTO was expected to be run by privateer teams in Group B and predominantly on tarmac rallies.

Audi Quattro

Imagine living up there, commuting would be a nightmare!

Imagine living up there, commuting would be a nightmare!

Initially, the Audi Quattro’s traction and power advantage allowed them to win the WRC in 1982 but by 1984 the purpose built rally cars such as the Peugeot 206 T16 were starting to show that they had more pace, although they were not quick enough to beat Audi in 1984. The most of Audi engineers working on the project suggested also making their own purpose built Group B car to help reduce the understeer that the drivers were experiencing, but Audi said no due to the negative press the Audi Quattro (their flagship model) would get. This meant that the Audi engineers created the Sport Quatro S1 by shortening the wheelbase, to reduce weight and increase turn-in capabilities, this made things worse in some ways due to there being less weight on the rear axle (62.1% on the front when there used to be 60%). Another benefit of there being less weight on the rear was that if the car was driven right the reduced rear stability could offset the effects of the understeer in high speed corners (it was still a problem in the slower corners). The Sport Quattro S1 also got an upgraded turbocharged inline-5 engine that could produce 450bhp but only at very high rpms making it even more difficult to drive. To combat this Audi developed a 6-speed gearbox with closer ratios before moving on to and adapted version of the Porsche PDK. The Audi drivers found it hard to adapt to all the changes with Michèle Mouton and Stig Blomqvist finding it particularly difficult. Stig Bloqvist ended up using the Quattro A2 and won the 1984 driver’s title. In early 1985 the Peugeot 205 T16 was still quicker than the Audis this led to the creation of the Audi Sport Quattro E2, the first time for rally cars to use aerodynamics to gain a traction advantage (the body work on the Audi Sport Quattro E2 is estimated to be able to produce 550kg of downforce). Everything that could be moved to the back of the car was to improve weight distribution meaning that now only 51% of the weight was at the front. Moving everything to the back also made it easier to work on the car. The inline-5 was further improved, mainly to make the torque more available in the mid-range and the horsepower being upped to 590bhp as well as a central torsion differential being added so the power didn’t have to be sent evenly between the front and back axle. Although the car was much improved Stig Blomqvist was still not happy with it and so was signed to Peugeot for the 1986 season. He later said his ideal Group B Rally car would be the longer wheel-base A2 Quattro with the E2’s mechanicals. Unfortunately, all of the improvements weren’t enough as Peugeot beat Audi in both the 1985 and 1986 seasons.

Thank you for reading.