With six consecutive victories in the World Rally Championship, the Lancia Delta HF 4WD/Integrale is arguably the most successful rally car of all time. At the end of the 1968 season, a series of accidents forced the cancellation of Group B racing, so the WRC shifted to Group A cars. Group B required 200 examples for homologation, however, Group A was production-based and required 5,000 examples. Lancia stepped up to the challenge, transforming the Giugiaro-designed four-door, front-wheel drive production Delta HF by adapting all-wheel-drive and increasing its engine capacity. The Delta S4 was the source of the AWD system with Ferguson center coupling and Torsen rear differential.
In mid-1986, Lancia introduced the Delta HF 4WD which was produced through 1987, after which the model was renamed Delta HF Integrale.
The new rally car was an immediate success, wearing the Martini Racing colors of Lancia's long-term Works sponsor. It won its first competitive event, the grueling 1987 Monte Carlo Rally. Of the 11 championship events, the Delta would be victorious in eight of those, delivering Lancia the world championship. In 1988, it won 10 of the 11 championship events, and in 1989, it won seven of the ten championship events. In 1990, the victories continued with six of the 11. The following year, it won six events and took four 2nd place finishes of the ten championship events.
After the 1991 season, Lancia officially withdrew from rally motorsports. However, Integrale's dominance continued, winning another eight of 10 events in the hands of Martini Racing in the 1992 season.
Built between 1991 and 1992, Lancia produced the ultimate homologation version of the Delta HF Integrale, the Evoluzione. It was powered by a 16-valve version of the turbocharged 1,995-cc engine producing 210 bhp in street tune. The second-generation 'Evo 2', produced from 1993 to 1994, was introduced and is generally recognized as retaining the closest connection to the Group A cars.
After winning its fifth Group A Constructors Championship in 1992, Lancia celebrated by introducing a limited edition Delta Integrale Evoluzione 16V 'Martini 5.' Four hundred examples were built and they were all liveried with the iconic Martini stripes running down each side, commemorative 'World Rally Champion' badging, Recaro seats trimmed in dark gray Alcantara with red stitching, and red seat belts.
by Dan Vaughan