The American V-8’s future looked wobbly emerging from the late 1970s. And Ford, hedging its bets, decided to test public sentiment in alternatives. Its Mustang M81 pushed toward a small-displacement ’80s turbocharged future that in some ways, foreshadowed this year’s news: Ford announced that its facelifted 2018 model would drop the V-6 engine, leaving just V-8 and turbocharged four-cylinder engines for Mustang buyers’ choice.
The plan was ingenious: Aim Ford, Firestone, Motorcraft and McLaren’s resources into building the racing and road cars to generate interest for factory production. It worked and the McLaren Mustang M81 was born. Success at the 24-hour Daytona race in 1981 – and the production of 10 hand-built road cars – established the formula for turbo four-cylinder Mustang performance ahead of, and independent from, Ford Special Vehicle Operations (SVO).
Gary Kohs of Marketing Corporation of America was the force behind the M81 program. He outlined the Mustang to Harry Wykes and Todd Gerstenberger, who, Kohs said, designed the McLaren-orange Mustang on a sketchpad while at a Mexican restaurant in California.
Kohs consulted his friend Roger Bailey at McLaren, who he worked with on a McLaren-powered street rod and Donzi powerboat propelled by a turbo-charged Pinto engine (among other projects). “I said to Roger, here’s what we want to do,” Kohs recalled. “We want to create an image for the Ford Motor Company and we want to do it through McLaren. We want to build a McLaren Mustang.”
Wrapping up Team McLaren BMW efforts, Bailey adopted the Mustang M81 cause. McLaren had established a United States operation in 1969 based in Livonia, Mich., where the M81 racecars and 2.3-liter engines were built. The formation of McLaren International in 1982 saw the U.S.-based operation become McLaren Engineering, still in powertrain and driveline development and still in Livonia.
Ed Nathman spearheaded the racecar build. As four-cylinder performance was at the core of the M81 project and IMSA rules allowed for an engine change, the racecars were equipped with Cosworth twin-cam BDA engines with Weber carburetion, Ford 4-speed manual transmissions, quick-change rear ends and Firestone HPR radial tires.
The M81 crashed early in its first outing at Daytona in ‘81, but after a pit thrash and many yards of duct tape, the car finished the 24-hour race on its shaved Firestones with drivers Tom Klauser and John Morton. That made news in American and European magazines - tape patching and all.
The road cars were hand-built from production Mustangs, with body modifications and wastegate hoods created by Dave Kent of Creative Car Craft. Power came from McLaren-worked Ford 2.3-liter turbo engines. The production fours were extracted at McLaren in Livonia for what engine master Wiley McCoy said was a “hot rod tune up,” with head porting and blueprinting for durability and performance.
Beyond the worked turbo engine and body mods, the M81 road cars featured a Koni-damped suspension with heavy-duty front and rear stabilizer bar, and BBS wheels with Firestone HPR tires. Recaro LS seats up front, Stewart Warner instrumentation, a Racemark steering wheel and a roll bar rounded out the interior. Air-conditioning was optional.
The carbureted and turbocharged Ford 2.3-liter engine was no brute by contemporary standards, but it was respectable. Two M81 Mustangs were set up with a dash-mounted boost controller, allowing 190-plus horsepower, but were sold with a caveat emptor, Kohs said. “We said ‘no warranty if you blow it up’ with the boost!”
The hand-built M81 cost about $25,000, but this Mustang special never made it to production for reasons unrelated to cost or enthusiasm. “We absolutely had it to the point where Ford said ‘what a great project’ and we actually did feasibility studies for putting them down the assembly line,” Kohs said. “There was no problem.”
Except for politics, that is. Credit for the M81 is often attributed to Ford’s SVO group, but this was not the case. Ironically, it was resistance from the nascent SVO that, in part, felled the M81, despite its success on the racetrack and road. Nearly four decades later, the M81 still generates interest in what could have been an alternate Mustang timeline.