Seversky continued to develop the design with the hope of selling more aircraft both to the Air Corps and to civil and export customers. It modified the prototype SEV-1XP as a single seat racer, the S-1 entering it into the 1937 Bendix Trophy, where it finished in fourth place. The competition was won by the S-2 (registration number NR70Y), a similar aircraft built for Frank Fuller of the Fuller Paint Company. S-2 also won the Bendix Trophy in 1939 and placed second in 1938. The aircraft was used to portray the "Drake Bullet" in the 1938 film "Test Pilot".