Groub B Rally Cars

[Cotterik]

Thread by Cotterik + Mustang

FIA (International Automobile Federation) introduced Group B in 1982 as the most exotic category in motor rallying. The regulations for Group B required the manfacturers to build only 200 road cars, very much lower than Group A's 5000 cars. Besides, more modifications were allowed for the race version. Therefore car makers could put as much state-of-the-art technology as possible into their racing cars.

This created a golden era in motor rallying history - Audi, Lancia, Peugoet, Ford, Citroen and Austin Rover created many super rally cars to compete in World Rally Championship, all with at least 400 horsepower, lightweight Kevlar body and most of them were mid-engined and 4-wheel drive also. Recalling that period, motor rally enthusiasts always regard that as the best moment of their life. WRC had never been as exciting as that period.

What a pity the Group B ended in misery. In 1986 season, series of accidents involving spectators as well as led to the death of Lancia's top driver Henri Toivonen and navigator Sergio Cresto happened. Group B was accused of being too powerful and too light to be controllable. As a result, FIA axed it after that season.

[Cotterik]

Since 1981, Audi stormed the rally world with its 4WD pioneering Quattro and established the reputation as King of Rally. In fact, Audi was not unbeatable. The biggest insult came when it was beaten by the rear-wheel drive Lancia 037 in 1983, this proved that a winning car also need a complete good package besides the drivetrain. Therefore it went to the drawing board again and created the mighty Quattro Sport - the most powerful rally car in history.

The 2133 c.c. all-alloy 5-cylinder unit had 4-valve head plus a big turbocharger. Maximum power in race car reached 500 hp, while the road car still managed to put out 300 hp. No wonder R&T recorded 3.6 sec for 0-60 mph and 11.8 sec for quarter mile for the race version, both were faster than Peugeot 205T16, Ford RS200 and Lancia 037.

The chassis was as conservative as the normal Quattro road car - steel monocoque was retained, front-engined configuration remained unchanged. To reduce weight and enhance nimbleness, wheelbase was shortened by a massive 12.6 inches. This led to the very strange-looking appearance - it simply looked like a Quattro coupe with the center section chopped away. Short wheelbase married with long overhangs in front and tail, what a contrast to today's design philosophy !

The body was made of mostly Kevlar, some aluminium and glass-fiber, just like other Group B cars. Also like other Group B cars, the Quattro Sport road car was very difficult to drive. It was very raw, too.


Engine

No. cylinder

5 in line

CC (x1.4 if turbocharged)

2110 (2954)

Bore / Stroke (mm)

79.5 / 85

Comp. Ratio

7,5:1

Max.Power (bhp)

444

Revs.

7500

Max.Torque (kg/m)

49

Revs.

5500

Induction

Bosch Motronic

Turbo

Inj. KKK Turbo

No. Valves

20

No. + Position Cams

2 Overhead Camshaft

Location

Front-Longitudinal

Transmission

Location


4WD

Differential (Front-Central-Rear)

Clutch (Manufacturer)


2 plate

Gearbox (Manufacturer)

6 speed

[Mustang]

here are some more pics


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[Mustang]

and some more of all the cars with info about them

http://www.stormloader.com/groupb/gallery.html

[Cotterik]

Undoubtedly, the emergence of Peugeot 205 T16 represented a new generation of Group B cars which could eat the old generation (headed by Audi Quattro Sport) for breakfast. While Quattro Sport was still front-engined, with a heavy monocoque chassis, Peugeot redefined the rules as mid-engined, space frame chassis and at least 100 lb lighter.

The 1.8-litre 16 valves turbocharged four generated up to 440 hp in race form but only 195 hp in road trim - in fact, unlike Audi and Ford, Peugeot (as well as Lancia S4) had no intention to fulfill the customers' expectation. All it wanted was to win the WRC and spend as little to the road car development as possible.

However, the road car still (had to) shared most of the advanced technology with the race car, including the unique center differential which enable on-board selection of different torque slit ratio between front and rear axle. Driver might select the most suitable setting for different kinds of road.

Engine

No. cylinder

4 in line

CC (x1.4 if turbocharged)


1774 (2485)

Bore / Stroke (mm)


83 / 82

Comp. Ratio


7,0:1

Max.Power (bhp)


450

Revs.


8000

Max.Torque (kg/m)


50

Revs.


5500

Induction


Bosch

Turbo


Garrett

No. Valves

16

No. + Position Cams


2 Overhead Camshaft

Location


Mid-Transverse

Transmission


Location


4WD

Differential (Front-Central-Rear)


Clutch (Manufacturer)


2 plate

Gearbox (Manufacturer)


5 speed

Brakes


Front


DV303

Rear


DV303

Suspension (shock absorbers)


Front


Wishbone+Coil

Rear


Wishbone+Coil

Dimensions


Length (mm)


3825

Widht (mm)


1674

Height (mm)


1353

Wheelbase (mm)


2540

Front track (mm)


1430

Rear track (mm)


1430

Weight (kg)


910

Date 1st Homologation (number)


1.4.1984 (B262) E2 1.4.1985

1st Major Rally


Corsica 1984

Debut: 205 Turbo 16 E2


Corsica 1985

WRC Wins (16)


Finland 1984 (Vatanen)


Italy 1984 (Vatanen)


RAC 1984 (Vatanen)


Monte Carlo 1985 (Vatanen)


Sweden 1985 (Vatanen)


Portugal 1985 (Salonen)


Greece 1985 (Salonen)


New Zealand 1985 (Salonen)


Argentina 1985 (Salonen)


Finland 1985 (Salonen)


Sweden 1986 (Kankkunen)



Corsica 1986 (Saby)


Greece 1986 (Kankkunen)


New Zealand 1986 (Kankkunen)


Finland 1986 (Salonen)


RAC 1986 (Salonen)

[McReis]

I was expecting new pics...

[Mustang]

Lancia 307



It was developed based on Lancia Beta Monte Carlo, a mid-engined sports car that looked better than it went. Even in rally form, its low-body and tilt-windscreen told you its real nature. Its 2.0 engine was modified by Abarth, with 16 valves and a root type supercharger added to boost power to 205 hp. In race car form, even the final Evolution 2 had only 325 hp, well below the average of 400 plus for its competitors. In addition, being the earliest Group B car, Lancia Monte Carlo 037 was driven by rear wheels, so Lancia eventually replaced it with the Delta S4.

Model

Lancia Monte Carlo 037
Year of production

1982
Layout

Mid-engined, Rwd
Chassis

Steel monocoque with glass fiber body
Engine

Inline-4, dohc, 4v/cyl, supercharger
Capacity

1995 c.c.
Power

205 hp
Torque

173 lbft
Gearbox

5M
Weight

1170 kg
Top speed

137 mph (estimated)
0-60 mph

7.0 sec (estimated)

[Mustang]

307 #2

[Mustang]

307 #3

[Mustang]

307 #4

[Mustang]

307 #5

[Mustang]

307 #6

[Mustang]

307 #7

[Cotterik]

Being one of the most high-tech cars ever built, Delta S4 had a legendary and dramatic fate. It had actually no relationship with the production Delta series, as you can see from its mid-engined design and tubular space frame chassis. It was designed for pure racing purpose from day one, aiming to beat Peugeot 205T16 and Audi Quattro Sport in Group B world rally championship. It would have done that, if fate was not against it.




Although Lancia already had a mid-engined race car called "037" (or "Monte Carlo" for road version), this car was found outpowered (only 325hp, compared with 440hp of Peugoet and 500hp of Audi) and outhandled by rivals (2WD only, unlike Audi and Peugeot's 4WD). Therefore Lancia had to develop the Delta S4 as a replacement.

Like contemporary rivals, Delta S4 was styled and named to promote the mass-production Delta. In fact, under the skin it was a clean sheet design. Being disagreed with Audi Quattro Sport's front-engined theory, it adopted the more popular mid-engined layout. The engine was longitudinally mounted behind the front seats, directly driving the viscous-coupling LSD which transfered 30% torque to front wheels and 70% to the rear. At each of the corners of the steel tubular space frame chassis, double wishbones and twin absorbers were employed as suspensions. All these were covered by a glass-fibre / epoxy resin composite body. (Kevlar for race car)

While its 4WD system was not as advanced as Peugeot 205T16's (which had variable torque split between front and rear axles), its engine was by far advancer. As I know, it was the only car ever employed turbocharger and supercharger simultaneously.


Turbocharger is generally regarded as the most efficient means of forced induction, but it requires higher rev (hence a lot of exhaust gas) to operate. The result is poor low-speed power and the presense of turbo lag. On the contrary, supercharger performs strongly and instantly right from idle, but it is rahter inefficient in high rpm. For a rally car, a flat torque curve over a wide range of rpm is always very crucial, since rally car has to brake to very slow in tight corners and then accelerate to near top speed in 10 seconds. Therefore Lancia spent a lot money with Abarth to develop a system combining both turbocharger and supercharger to get a perfect output. It employed twin intercoolers, one for the turbo and one for the supercharger. The supercharger worked at low speed. Once the turbo cut in, a bypass valve relieved the pressure from the supercharger so that energy efficiency was be lifted.

This system was not only complex, but also faced great difficulties during development. The biggest problem was the transition between supercharging and turbocharging, since a short zero-boost period existed. However, after further developement, this problem was eventually solved.

As a result, the 1.8-litre engine had an outstanding power of 250 hp and a healthy 214 lbft of torque, while the rally car had at least 470 hp and 333 lbft.

Like other Group B cars, only 200 units of road version were made to fulfill the minimum requirement for homologation.

In WRC, Delta S4 experienced a dramatic fate. It won its debut race, then continued to dominate the following races and was leading both the driver and manufacturer championship standings. Such excellent results amazed everyone, since it was a completely new car. In 1986, Tour de Corse (Corsica Rally), leading driver Henri Toivonen and navigator Sergio Cresto crashed in their S4 and both were killed. The team lost its momentum and eventually handed the title to Peugeot. This accident led to the rethink of Group B cars. Races went on but finally FIA annouced the termination of Group B, because it was too powerful and dangerous. Therefore, Delta S4 became the most outstanding rally car in history that did not won world title.



Model

Delta S4
Year of production

1985
Layout

Mid-engined, 4wd
Chassis

Tubular space frame + box section structure, glass-fibre + epoxy body panel
Engine

Inline-4, dohc, 4v/cyl, turbo, supercharger.
Capacity

1759 c.c.
Power

250 hp
Torque

214 lbft
Gearbox

5M
Weight

1200 kg
Top speed

140 mph (claimed)
0-60 mph

6.0 sec (claimed)

[Mustang]

307 #8