Lancia's Delta S4 was a rally car developed for the WRC's short-lived Group B category, where the cars had a massive power output compared to their Group A counterparts. Like all Group B rally cara it had a civilian version called the Delta S4 Stradale.
It had an Abarth tuned 1,759 cc inline-4 engine, which produced 550 horsepower; made possible by the use of a turbocharger and supercharger; a system called twin-charging.
The S4 made it's debut at the 1985 event of the RAC Rally (now called the Wales Rally GB) and won that event; at the hands of up-and-coming Finnish rally driver Henri Toivonen; who also won the Monte Carlo Rally of 1986.
Sadly however, with so much unfulfilled potential left, Toivonen and his co-driver Sergio Cresto; both died in the 1986 Tour de Corse, when their S4 Delta missed a tight left-hand hairpin and plunged off into a wooded ravine and exploded in flames; leaving only the badly burnt spaceframe and chassis. The crash was nearly a year after Lancia's Attilio Bettega died after crashing his Lancia 037 (the car that was replaced by the S4.)
A comment made by Cesare Fiorio, then team boss of the Lancia rally team, just told of how much unfulfilled potential Henri Toivonen still had to show; as he was the only driver on the team who could control Lancia's S4 Delta but Toivonen himself said that the car had a mind of it's own and that he himself didn't know how to drive it.
