Gérard Welter and Michel Meunier, both designers from Peugeot, began building racing cars in their spare time in 1969, starting with a modified Peugeot 204 convertible they named the WM P69. They continued developing cars, making their debut at Le Mans in 1976 with a GTP car powered by a Peugeot PRV engine.
Following years of development, Welter and Meunier focused their efforts on breaking the 400 km/h barrier on the Hunaudières straight at Le Mans. This ambition led to the creation of the WM P87, an evolution of their previous cars. The P87 was followed by the WM P88, built with assistance from the French coachbuilder Heuliez. The P88 refined and lightened the P87, saving 65 kg, and featured new rear suspensions and a larger displacement engine.
In 1987, the WM P87 reached 416 km/h (258 mph) during an exhibition on the A26 motorway, demonstrating the car’s potential. However, during the 1987 24 Hours of Le Mans, the P87 was forced to retire due to engine damage caused by poor-quality fuel. Despite this, speed detectors recorded the car at 381 km/h during the race.
The following year, in 1988, the WM P88 reached 387 km/h in qualifying at Le Mans. During the race, driver Roger Dorchy achieved speeds exceeding 400 km/h for several laps, with a maximum recorded speed of 407 km/h. Peugeot, however, chose to publicize a slightly lower figure of 405 km/h for marketing purposes related to their new 405 Sedan. Ultimately, the P88 retired due to electrical problems, cooling issues, and turbo failure.
The 1989 24 Hours of Le Mans saw Welter Racing fielding both a P87 and a P88, renamed the P489 with minor updates. During testing, one of the P489s (#51) suffered a fire and was irreparably damaged. Another (#52) experienced a tire explosion at the end of the Hunaudières straight, though the driver, Pascal Pessiot, maintained control. The remaining P489 retired from the race when Pascal Pessiot’s engine failed near the Mulsanne corner, subsequently catching fire.
Following the 1989 season, Gérard Welter and Michel Meunier dissolved their company, marking the end of Welter-Meunier’s involvement in racing. The WM P88 was later sold as part of a corporate restructuring of the Heuliez collection in 2012, without its record-breaking engine, which remains in the possession of Gérard Welter.
The high speeds achieved by the WM P88 and other prototypes prompted the FIA and the ACO to modify the Hunaudières straight at Le Mans in 1990, adding chicanes and effectively ending the possibility of reaching 400 km/h on the straight.