The Lancia Delta Group A is a Group A rally car built for the Martini Lancia by Lancia to compete in the World Rally Championship. It is based upon the Lancia Delta road car and replaced the Lancia Delta S4. The car was introduced for the 1987 World Rally Championship season and has dominated the World Rally Championship, scoring 46 WRC victories overall and winning the constructors' championship a record six times in a row from 1987 to 1992, in addition to drivers' championship titles for Juha Kankkunen (1987 and 1991) and Miki Biasion (1988 and 1989).
During the early 1980s the top level of rallying was dominated by the Group B formula, for which Lancia produced the rear-drive 037 and then, when that became obsolete, the Delta S4. The entire formula was abolished at the end of the 1986 season, however, after a string of fatal accidents, leaving Group A as the top formula for the 1987 and subsequent seasons.
The sudden change in the rules left many manufacturers without a suitable car, with the exception of Lancia. The Delta HF 4WD (Abarth SE043), with its two-litre turbocharged engine and four-wheel-drive, was clearly a more suitable Group A rally car than its rivals, the underpowered Mazda 323 and Ford Sierra XR4x4, the powerful but rear-drive Sierra Cosworth and BMW M3, and the front-drive Opel Kadett GSi and Renault 11 Turbo. However, it was not without flaws. The wheel arches were restrictive, the wheels and therefore the brakes were too small, and the suspension travel was limited. Access to key components for servicing was also restricted by the car's compact size and transverse-engined layout, the one defect that subsequent evolutions could not fully rectify. Even so, little doubt was expressed before the 1987 season began that Lancia, and one of its drivers, would win the World Championship.
In 1987 the Lancias were driven by Massimo Biasion, Juha Kankkunen and Markku Alén. Biasion opened with victory in the Monte Carlo Rally and later in the season won the Argentina and Sanremo rallies. However, Juha Kankkunen’s four podium places, coupled with victories on the Olympus Rally and the final round, the RAC Rally, saw him clinch the title ahead of Markku Alén, whose title hopes ended on the RAC with a series of accidents, including overturning the car in front of the television cameras on one of the opening day's short spectator stages. Lancia won seven of the eleven rounds which counted towards the manufacturers’ championship and with them the world title. However Kankkunen, reputedly disillusioned with team politics and the apparent favoritism shown towards Biasion, left the team at the end of the season and rejoined Toyota.
The Delta HF 4WD also won the first two events of the 1988 season, Bruno Saby taking the win at Monte Carlo and Markku Alén in Sweden, before the Integrale 8V (Abarth SE044) appeared at the third round in Portugal. Team boss Cesare Fiorio remarked in an interview before that event that the Integrale’s larger wheels, bigger brakes, improved suspension and greater power would make it more competitive on asphalt, although on gravel it represented a relatively small improvement over the 4WD. Markku Alen went out with transmission failure early in the event, giving rise to some concern about the strength of the transmission and causing the team to undertake a great deal of precautionary maintenance to Biasion's car. However, the Italian driver suffered no serious mechanical problems and continued to take victory. A new and stronger six-speed gearbox was already under development and was introduced for the next event. Lancia then dominated the rest of the season. Only once were they beaten in a straight fight, on the dry asphalt of Corsica by Didier Auriol in a Ford Sierra RS Cosworth. By the season’s end Lancia had won ten of the eleven rounds which counted for the manufacturers’ series, and Biasion was drivers’ World Champion, having clinched the title on the penultimate round. Markku Alén rounded off the season with victory on the RAC Rally, a personal first for the Finn.