This Proto Ferrari MR400 is one of approximately ten examples reportedly produced and represents a fascinating meeting of French engineering innovation and Ferrari performance. Developed around the ideas of legendary French engineer Claude Fior, the MR400 is an uncompromising sports prototype built with lightweight construction, race-car packaging, and competition-oriented mechanical components throughout.

Claude Fior is widely regarded as one of France’s most original and innovative chassis engineers. Best known for his radical motorcycle designs and for his work on the aluminum chassis development of the Renault Sport Spider and Spider Trophy race cars, Fior consistently pursued maximum rigidity, low mass, and unconventional engineering solutions. The MR400 embodies many of those same principles and stands today as one of the most unusual and scarcely documented Ferrari-powered prototypes of its era.

Power comes from a Ferrari Tipo F119H 3.4-liter quad-cam V8 carrying engine number 137970. This later-evolution engine corresponds to the specification used in late-production Ferrari 348 GTB and GTS models and benefits from revised engine management, increased compression, and numerous internal refinements that raised output to approximately 320 horsepower—roughly twenty horsepower more than the earlier 348 tb and ts specification. Power is sent to the rear wheels through an original Ferrari manual transaxle.

The car is fitted with fully independent competition suspension, AP Racing braking components, and center-lock Speedline Corse wheels. The purposeful cockpit features a minimalist race-oriented layout with carbon-fiber-look dashboard trim, competition switchgear, aluminum pedal box, and integrated safety equipment. The engine’s timing system was serviced in 2022, and the car currently displays approximately 156 engine hours.