Published on: Feb 5, 2016 @ 19:43 Originally Published in: 2015 (old website) (C) Jay Auger - website owner & author Notice: Any form of duplication methods (including but not limited to copy/paste of text and screen capture) of the website's content is strictly forbidden.
INTRODUCTION
Brainchild of Tony Fall, the Group 4 Ascona B 400 was developed to replace the Group 1/2 Kadett GT/E and put Opel on top of the international and World Rally Championship (WRC) scenes.
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HISTORY
First shown at the Frankfurt Auto Show in September of 1979, the “B 400” variant was an homologation special produced especially to make the Ascona eligible for rallying’s top Group 4 category. It was aimed to compete directly against the Ford Escort RS1800 and Fiat 131 in both national and international rallies. As such, the car featured a traditional chassis paired with rear-wheel drive. Engine specialist Cosworth (which had greatly helped Ford achieve success with their Escort) was given charge of building the engines while specialist Irmscher would take care of the bodywork modifications.
As it was often the norm in racing, the plan was to use the engine from the outgoing rally car, in this case the Kadett GT/E’s 2.0L unit, but these did not produce enough power for Group 4 competition. Therefore, many alterations were made to the engine to fix the output problem; the cylinders were bored out to make use of larger pistons, different connecting-rods, and used the much beefier crankshaft of Opel’s CIH diesel engine.
The new 2420 cc engine gave rise to some massive power outputs while using the Cosworth 16 valve head: in race trim the normally aspirated engines delivered a base power of 230 BHP with a maximum expected output of 340 BHP (albeit with much reduced reliability).
About a year later in 1980, the FISA officially announced the approval of the complete revamp of its regulations which would introduce the new Group B category set to begin in 1982. Not long afterwards in 1981, Audi introduced the quattro which would soon become the Ascona’s fiercest competitor in the WRC.
Furthermore, the second generation of the Ascona was soon to be replaced by a third generation. As such, Opel chose the shift its motorsport branding image to the new second generation of the Manta (the Ascona’s sister car) to build their upcoming Group B machine instead. Both cars would be subsequently developed at the same time.
In 1982, per the transition rules allowed, the Ascona was transferred from Group 4 into Group B. Near the end of the year, Opel would implement a few improvements to the car, also known as “phase 2”, in hopes to retain the competitiveness of the car while the Manta replacement was being finalised. These improvements mainly featured the switch to composite materials for body panels and screens.
The Ascona gave the Audi quattro a good fight in the WRC but fell short of the manufacturers championship. It did however provide Walter Röhrl with his second drivers title. As history would unfold, that would be the last time that a driver won the WRC championship with a rear-wheel drive car, hence securing the Ascona’s spot in motorsport history.
In early 1983, Ari Vatanen would give the Ascona a fairy tale ending with a victory at the Safari Rally, its very last event. For the next rally, Opel had to forcibly retire the Ascona and switch its international Group B rallying efforts to the further improved Manta B 400 (also known as “phase 3”) to retain the eligibility of scoring points in the WRC.





Ultimately, the bad timing of its introduction and the infamous engine teething issues prevented the Ascona from achieving a long and successful rally career on the international scene. However, many privateers would continue to rally the car and achieved much success in national events. Today, the car is a mainstay of historic rallies around Europe.







RALLY CAR SPECIFICATIONS
The following specs are for the “phase 2” Group B version.
Group/Class | B/12 | Homologations:
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Years active | 1980~1986 | Homologation start:
Homologation end:
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Engine | |||
Type | 4S “phase 2” with Cosworth “crossflow” cylinder head, I-4, DOHC 16v, gas | located front longitudinal | |
Capacity | 2420 cc | WRC: 2420 cc | |
Compression ratio | 11.5:1 | ||
Output power – torque | 270 HP @ 7000 rpm | 214 lb-ft @ 5000 rpm | |
Materials | block: cast iron | cylinder head: aluminium | |
Aspiration |
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Ignition | electronic, firing order 1-3-4-2 | ||
Cooling system | water-cooled | ||
Lubrication system | dry sump | 15 liters | |
Transmission | |||
Type | rear wheel drive | 5 speed getrag gearbox | |
Gearbox ratios | constant input: 1.038/1 (27/26) 1st: 2.337/1 (36/16) 2nd: 1.671/1 (34/21) 3rd: 1.355/1 (30/23) 4th: 1.163/1 (28/25) 5th: 1.000/1 (direct) R: 2.650/1 (41/16) |
constant input: 1.652/1 (38/23) 1st: 3.717/1 (36/16) 2nd: 2.403/1 (32/22) 3rd: 1.766/1 (31/29) 4th: 1.263/1 (26/34) 5th: 1.000/1 (direct) R: 4.230/1 |
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Diffrential ratio | from 6.1/1 to 3.180/1 | hypoid spiral bevel gears, 75% – 80% limited slip rear differential | |
Clutch | dry – double plate | ||
Chassis-body | |||
Type | steel monocoque chassis with steel roll cage, steel front subframe for front suspension. 2 doors coupe steel/plastic bodyshell with plastic bonnet, front and rear bumbers and spoilers | ||
Front suspension | double unequal wishbones with coil springs, Bilstein gas shock absorbers and anti-roll bar | ||
Rear suspension | live axle with 4 longitudinal links, panhard rod, coil springs and Bilstein gas shock absorbers | ||
Steering system | rack and pinion |
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Brakes |
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adjustable dual circuit with servo | |
Dimensions | |||
length: 4320 mm (170.0 in) | width: 1760 mm (69.3 in) | height: 1360 mm (53.5 in) | |
wheelbase: 2518 mm (99.1 in) | front track: 1387 mm (54.6 in) | rear track: 1375 mm (54.1 in) | |
Rims – tires | 5″~8″ x 14″~15″ | Michelin TRX 135-250TR290, 205/50 R14 | |
Dry/Unladen Weight | 1050~1100 kg (2315~2425 lb) | ||
Weight/power | 3.9 kg/hp (8.6 lb/hp) | ||
Fuel tank | 60 lt, 80 lt, or 110 lt |
HOMOLOGATION VERSION

The “B” stands for the second generation of the model, while the “400” moniker comes from the required units aimed specifically to acquire Group 4 homologation for use in rallying. As such, only 400 of these special two-door Asconas were produced in 1979.
The car featured a few improvements over the normal Ascona production models, more prominently in the basic “phase 1” engine that produced 144 BHP in street trim. The wide arches, body kit, and decals were optional features that were fitted out of factory by German specialist Irmscher.
ROAD CAR SPECIFICATIONS
Class | Sports | Homologations:
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Years produced | 1979 (400 units) | Assembly: Germany |
Engine | ||
Type | “24E”, I-4, DOHC 16v, gas | located front longitudinal |
Displacement | 2420 cc | |
Compression ratio | 9.7:1 | |
Output power – torque | 144 HP@ 5200 rpm | 155 lb-ft @ 3800 rpm |
Materials | block: cast iron | cylinder head: aluminium |
Aspiration |
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Ignition | electronic, firing order 1-3-4-2 | |
Cooling system | water-cooled | |
Lubrication system | N/A | N/A |
Transmission | ||
Type | rear wheel drive | 5 speed gearbox |
Gearbox ratios | N/A | N/A |
Differential ratio | N/A | N/A |
Clutch | dry – single plate |
Chassis-body | ||
Type | steel monocoque 2 door sedan chassis. Optional body kit consisting of; Irmscher front & rear wheel arch extensions, side skirts, rear spoiler | |
Front suspension | double unequal wishbones with coil springs, Bilstein gas shock absorbers and anti-roll bar | |
Rear suspension | live axle, radius arms, panhard rod, coil springs and Bilstein gas shock absorbers | |
Steering system | rack and pinion | N/A |
Brakes | N/A | N/A |
Dimensions | ||
length: 4320 mm (170.1 in) | width: 1670 mm (65.7 in) | height: 1360 mm (53.5 in) |
wheelbase: 2518 mm (99.1 in) | front track: 1387 mm (54.6 in) | rear track: 1375 mm (54.1 in) |
Rims – tires | 6J x 14 |
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Curb Weight | 1082 kg (2385 lb) | |
Weight/power | 7.5 kg/HP (16.6 lb/HP) | |
Fuel tank | N/A |
VIDEOS
REFERENCES
AWIN Affiliates Program – by purchasing books with the links provided here you are also helping to support the Rally Group B Shrine!*
Group B – The rise and fall of rallying’s wildest cars (English)
Gruppe B – Aufstieg und Fall der Rallye-Monster (German)
Group 4 – From Stratos to quattro (English)
Gruppe 4 – Das Jahrzehnt der Heckschleudern (German)
(C) Article by Jay Auger – website owner, main author & chief editor
- Images & videos are the property of their original owners
- All homologation papers are the property of the Fédération Internationale de l’Automobile (FIA): SOURCE
- Eifel Rallye Festival Pictures used under permission – McKlein Publishing
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DISCLAIMER / LEGAL NOTICES
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