After creating a distinguished reputation as developers and manufacturers of aero engines, the French Société Des Moteurs Salmson diversified after the First World War into the manufacture of machine tools and automobile bodies, and from 1919 onwards produced a lightweight cyclecar under licence from GN.
Salmson’s own designs first appeared in 1921, created by Émile Petit, with a cyclecar-type chassis, shaft drive and a differential-less back axle, and powered by a 1,100cc overhead-valve four.
In 1927 Salmson introduced the ‘Grand Sport/Grand Prix’ (GS-GP). 18 cars of this type were produced ‘for racing only’, of which only two complete examples are believed to exist today. First used by the works in 1926 and offered to customers for the first time in 1927, the GS-GP was the last of this particular series of racing Salmsons and featured the latest version of the ‘San Sébastian’ dohc engine that had already been seen in some examples of the preceding GSS and GSC models.