The 637 originated from Enzo Ferrari's dissatisfaction with looming Formula One engine regulations that mandated a V8 configuration. Rather than accept the new rules, Enzo commissioned a purpose-built Indycar as both a genuine racing project and a bargaining tool against the FIA. Ferrari made no secret of his ambition to win the Indianapolis 500, though many within motorsport believed the CART program was principally a threat designed to pressure the governing body into softening its stance on engine specifications.
To research the CART environment, Ferrari approached Goodyear, who in turn recommended a partnership with the Truesports team for research and development. After the 1985 CART season, Truesports and driver Bobby Rahal traveled to Italy to demonstrate a March 85C powered by a Cosworth engine. Both Rahal and Ferrari works driver Michele Alboreto tested the March at Ferrari's Fiorano test track. Engineers subsequently disassembled the car and studied it in detail before designing their own machine.
For a car that began as a diplomatic lever, the 637 was a carefully engineered piece of machinery. Its construction combined an aluminium upper body mechanically bonded and adhesively joined to a lower carbon fibre monocoque chassis — a hybrid approach that reflected Ferrari's experience with composite materials in Formula One.
The powertrain was the Type 034 engine, a turbocharged 32-valve V8 displacing 2.65 litres with a 90-degree bank angle, built to meet CART technical regulations. The unit featured upward-mounted exhaust pipes, an unconventional routing that was part of the car's overall aerodynamic and packaging philosophy.
Michele Alboreto drove the 637 during testing in 1986, providing Ferrari's engineers with feedback on the car's behaviour in Indycar-specification configuration. The results were sufficiently encouraging to demonstrate the project's technical soundness, but Enzo Ferrari ultimately chose not to race the car himself.
The FIA revised its Formula One engine regulations in a manner that satisfied Ferrari's concerns, removing the principal motivation for a full CART programme. With the political objective achieved, Ferrari transferred the 637 chassis to Alfa Romeo, another company within the FIAT industrial group, which was seeking to raise its profile in the North American market.
Alfa Romeo had its own ambitions in American open-wheel racing and received the 637 chassis as the basis for further development. When Alfa Romeo eventually unveiled their 2.65-litre Indycar engine, it appeared in a March chassis for public presentation; however, the unit was tested privately at Fiorano in the 637 chassis. This cross-pollination reflected the shared resources and engineering relationships that existed across the FIAT group's racing subsidiaries during the 1980s.
The Ferrari 637 occupies a singular place in motorsport history as one of the very few purpose-built Ferrari racing cars never to have competed in an official race. Its existence illustrated the degree to which Formula One politics in the mid-1980s could redirect enormous engineering resources. The project also demonstrated that Ferrari possessed the technical capability to compete seriously in American open-wheel racing had commercial and regulatory circumstances aligned differently.
The 637 stands alongside a small number of other major manufacturers — including Lotus and Porsche — that explored or entered CART during the 1980s as the series attracted international attention. Unlike those programmes, Ferrari's venture remained permanently confined to the test track, a reminder of how closely motorsport ambition and regulatory negotiation were intertwined during the Enzo Ferrari era.