After bodywork testing with the prototype 934, 930 670 0001, the Porsche factory built its first 935 to actually race at the end of 1975. This was known internally as 935-001, or R15. The Chassis number was 930 670 0002.
The engine had a bore and stroke of 92.8 x 70.4mm, to give a cubic capacity of 2856 cc. With its single turbocharger, it produced 590 PS at 5,400rpm. The car weighed 970 kg.