This is the McLaren Mustang M81 prototype from when McLaren worked with Ford with plans for 250 units, to be built as a partnership between McLaren Engines and Ford’s SVO. Ultimately, only 10 were built due to the high price, and today they are among the rarest production Mustangs ever. McLaren Engines was founded in the United States in 1969 by racing legend Bruce McLaren, who was also the founder of the famous Formula One team of the same name.
The history of this Mustang is curious, to say the least. McLaren Engines was established as the primary facility for McLaren’s racing efforts in the United States, while McLaren in England remained focused on the company’s Formula One racing programme. Although today the McLaren name is better known for its long history in F1, the influence of McLaren engines on the North American scene was enormous. The company built engines for Can-Am, Indy, and for countless projects within the United States.
McLaren won five consecutive Cam-Am championships, built engines for three Indianapolis 500 winners, and developed a turbocharged version of the successful Cosworth DFV engine that powers both Team McLaren and Penske Racing’s IndyCar. It was acquired by Canada-based Linamar Corporation and operates as a subsidiary today, working with North American automakers on engine development.
By the time the McLaren Mustang M81 project was initiated, it was already well known in the United States due to the McLaren team’s successes in Can-Am racing. The team was dominated for years by gleaming Papaya Orange-stamped vehicles, all powered by highly modified American V8 engines after passing through their hands. The M81 McLaren Mustang was conceived as a 1980s version of the 1960s Shelby Mustang, one of the most desirable muscle cars today.
Ford’s Special Vehicle Operations (SVO) unit was established in the early 1980s and the M81 would be its first major project, preceded by the Ford Mustang SVO in 1984, which was very popular with nearly 10,000 being built between 1984 and 1986. It was sold in large numbers. In the United States and around the world, new emissions restrictions and fuel efficiency standards meant that the large displacement V8s of previous years would not cut it and new fuel efficiency technologies were needed.
For the new Mustang Fox body, Ford developed a 2.3-litre inline-four engine with a turbocharger that produced almost as much power as the 4.9-litre V8, with 131bhp versus 139bhp. In 1980, when the V8’s displacement was reduced to 4.2 liters and power reduced, the world turned upside down: for the first time, a four-cylinder Mustang was more powerful than the V8 version. Thus was born the McLaren Mustang M81, and all because Ford needed to make a turbo four-cylinder car better than a V8, and they turned to McLaren and its new SVO department for help.
SVO engineers took the standard Fox bodied Mustang and widened the wings in true IMSA style, fitted wider BBS alloy wheels, and installed functional brake ducts at the rear. This included bigger brakes, stiffer springs, adjustable Koni shocks, and matching stiffer anti-roll bars to complete the look, along with a new raised hood. Inside the car Recaro seats were fitted, a racemark steering wheel with Stewart-Warner watches was added, a bolt-on roll bar and air conditioning were offered as optional extras.
Now that it looked dangerous, it would need much more than the standard 131bhp. The engine was sent to McLaren Engines, who stripped it, and completely reworked the cylinder heads, fitted a new turbo that could produce 0.3 bar to 0.75 bar of boost pressure, this was adjustable from inside the car. This engine was capable of generating 175 hp at 0.7 bar and 210 Nm at 3,000 rpm, although it should be noted that the stated torque figure was at the lowest boost setting. By the standards of the time, the M81 was a beast and Ford planned to sell 249 of them, along with an additional car as a prototype.
Perhaps the biggest problem with the car was the cost of all those upgrades, as they weren’t cheap, starting at $25,000 in 1980, as high as $91,576 in 2023. At that price, many potential customers could add about $10,000 more and buy a Ferrari 308 GTS, forget the Mustang. Unsurprisingly, not many were sold, with only 10 being built, including the prototype, meaning they are among the rarest production Mustangs ever built.
Seven of them were finished in Bittersweet Orange (similar to McLaren’s famous Papaya Orange), one in black, one in white and two were Enduros. I haven’t been able to pinpoint exactly what color this last one is, but I think it must have been somewhere between the green and brown used at the time.