Lancia Delta S4

Gorgeous. Oh, and batsh*t crazy.

Someone described it as looking a bit like a hearse for short, wide people— which we think isn’t inaccurate.

The S4 featured a midship-mounted engine and all wheel drive for superior traction and handling. The car’s 1759 cc four cylinder engine combined supercharging and turbocharging to reduce turbo lag at low RPM. Officially the car produced 550 horsepower (410 kW). Independent figures show the S4 could accelerate from 0 to 100 km/h (62 mph) on gravel in just 2.3 seconds.

The method of turbocharging and supercharging an engine is referred to as twin charging. This technology is very rarely used because most racing restricts to one means of forced induction, and rarely on road cars as its benefits lie mostly in the realm of boost curve fine tuning (quicker boost response) and allowing for said with the use of a freer flowing turbine/housing spec on the turbo to make it more efficient (or less inefficient, compared to the tighter housing needed to minimise lag) at higher rpm. Such twin charging does still see use in some hillclimb racing, where throttle and boost response are paramount over peak power concerns. The S4 itself, when everything worked perfectly, managed to hit 2.2 bars (32 psi) boost (source).

Images: Michael Ward/autoitalia.co.uk


~ by velofinds on February 12, 2010.