The pinnacle of the S-series barchetta range was the 450 S, developed by G. Taddeucci for the engine and V. Colotti for the chassis and transmission, under the direction of Giulio Alfieri, in 1956.
The 4.5-liter inline V8 produced 400 hp at 7,200 rpm and could reach 320 km/h!

It became legendary by winning its first race, the 12 Hours of Sebring, driven by Fangio and Behra, and would go on to accumulate 23 victories in total.