Lancia introduced the Delta HF 4WD model in 1987 World Rally Championship, and they refined the car with different and successful versions. It was not until 1992 when they introduced a rear spoiler. In fact, it was designed by the factory to be incorporated into the road car spec, so the rally team decided to include it in the 1992 Super Delta HF Integrale model, since then best known as the Deltona.
D.Auriol/B.Occelli, Lancia Super Delta HF Integrale, Test in Corsica, December 1991
Pre-season tests developed in Corsica in December 1991 with Didier Auriol and Philippe Bugalski showed that the presence of the spoiler at the max angle of attack resulted very effective in reducing lift, and the car showed better stability. However, such position also led to significant increase in drag, resulting in reduced top speed and higher fuel consumption and rear tire wear.
P.Bugalski/D.Giraudet, Lancia Super Delta HF Integrale, Test in Corsica, December 1991
Road cars were supplied with the spoiler at an almost flat position, but two brackets were also supplied so the owner could raise it through two angles of attack. FIA homologated it in January 1992 (see the form here).
All cars used the spoiler at the higher angle of attack position since its debut in Montecarlo Rally 1992, where Didier Auriol led the car to another victory.
P.Bugalski/D.Giraudet, Lancia Super Delta HF Integrale, Montecarlo Rally 1992, 5th
The only race where rear spoiler was used at a flat position was 1992 Safari Rally, where maximum speed was privileged over lift reduction.
B.Waldegaard/F.Gallagher, Lancia Super Delta HF Integrale, Safari Rally 1992, retired
Lancia renounced to continue as Manufacturer in the 1992 Championship, after winning the make’s title for six consecutive years. The cars were run that year by Jolly Club, with the support of Martini, as Fiat had already taken the decision to withdraw in late 1991. For this reason, cars were inscribed under the name of Martini Racing, instead of Martini Lancia as in previous years.
J.Kankkunen/J.Piironen, Lancia Super Delta HF Integrale, Rally of Australia 1992, 2ond
For the driver’s title, and even the six victories of Didier Auriol in the year, he could not beat the regularity of Carlos Sainz (Toyota), who won his second title in the RAC Rally, before moving to the Italian team.
D.Auriol/B.Occelli, Lancia Super Delta HF Integrale, Tour de Corse 1992, 1st
Front brakes lacked sufficient air cooling, so in those rallies where brakes were extremely used they were forced to use external disks to force air into brake discs for cooling purposes.
In 1993, Lancia cars were run again by private team Jolly Club, this time with the support of Repsol as the main sponsor, and Carlos Sainz and Gustavo Trelles replaced Auriol and Kankkunen. The results in that year showed the loss of competitiveness of the Deltona in front of the new cars generation, led by Toyota and Ford, and the team concluded the year with no victory and only three podiums.
C.Sainz/L.Moya, Lancia Super Delta HF Integrale, Rally of New Zealand 1993, 4th
After such a disappointing year, the Italian team decided to completely retire from the Championship and only private drivers such as Alessandro Fiorio incidentally took part in some 1994 races.
Lancia Super Delta HF Integrale rear spoiler is one of the most vertical spoilers ever used in rally cars. However, as tests showed, it was really helpful to generate downforce at car rear, by generating a barrier to air flow thus promoting a sudden change in airflow direction and a sudden increase in pressure. The difference in pressure between top and bottom of the car was the origin of the resulting downforce and better car grip.
History continues, with the arrival of one of the most successful rally cars, the Ford Escort RS Cosworth.