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.
Photo courtesy of Peter McFadyen. See his website: http://petermcfadyen.co.uk
The GS Grand Prix series was based upon the first use of the works supercharged cars at the 1926 ACF Grand Prix at Miramas and are referred to in the factory records only as Grand Prix (no mention of San Sebastien (factory spelling)). San Sebastian is only referred to in the factory records for the GSC series.The GSC series is thought to have been based on the car used by Casse to win the 1925 (17 Sept.) Gran Premio do San Sebastian (although some earlier Service de Course GSS cars were built to the same spec.). This car if thought to be the first competitive use by Salmson of the Perrot Piganeau front axle and the production dual ignition engine. No GSC’s were supercharged from new. All Gran Prix were supercharged.