The Group B rally car rivalry, spanning from 1982 to 1986, witnessed intense battles among major automakers like Audi, Citröen, Fiat, Ford, Lancia, Opel, Peugeot, and Rover. Despite its brief existence, this class encouraged groundbreaking innovation, introducing technologies like all-wheel drive, ‘twin-charging,’ and Kevlar materials. One standout was the Lancia Delta S4 Stradale, conceived as the successor to the Rally 037.
Built to comply with the 2,500cc class regulations, the Delta S4 prioritized a lightweight, all-wheel-drive platform, competing against the Peugeot 205 T16. Breaking from tradition, this Lancia model, entering the 890kg weight class, became the most potent Group B Rally car for the brand, winning its debut at the 1985 RAC Rally.
Built with a CroMoly steel tubular space frame reinforced with aluminum alloy, the Delta S4’s chassis allowed easy maintenance in demanding rally conditions. Its rear-mounted 1,759cc engine featured aluminum cylinder bores and a hardened ceramic surface, utilizing a twin-charged forced induction system—blending a responsive supercharger and a turbocharger—to deliver 247bhp at 6,750rpm and 215 lb-ft torque at 4,500rpm.
While the Delta S4 Stradale is an extraordinary piece of automotive history as revealed by Henry Catchpole in his video shared on Hagerty YouTube channel, the car saw limited success in the market due to its high price and the rapid evolution of rallying.
