This rally car was built by Antonio Zanini, who decided to convert a regular Citroen AX to Citroen AX 4x4. The engine used in that rally car is from Citroen Visa 1000 Pistes, which was Citroen's main rally car in WRC from 1984 to 1985.

Source- rallyfc.mforos.com/1288292/8033557-prueba-comparativa-citroen-ax-proto-turbo-y-compresor/