Ford’s Heritage Fleet Revived a V10-Powered Mustang Prototype After Almost 25 Years

• This Prototype was made in 2002 to prove a V10 engine could fit under the hood of the then-current Mustang.

• This project didn’t lead to a production version, and the prototype was left to sit in a garage.

• The automaker’s heritage fleet teamed up with the original engineers to revive this one-of-a-kind Mustang.

While most automotive prototypes lead a fairly short life, being scrapped once their auto show or development duties are complete, some manage to stick around much longer.

The latter is the case for a V10 Ford Mustang prototype from the early 2000s, which remained stashed in a garage until very recently, when the automaker’s heritage fleet got hold of it.

Meant more as a proof of concept than a showpiece, this prototype never really made a public appearance at the time of its creation in 2002 and quickly disappeared from the radar, making it somewhat of a mythical tale among Ford employees.

Nevertheless, this one-of-one V10-powered SN95 Mustang is very much real, and it is now alive too, having completed a dyno run after the Ford heritage team completed the work needed with the help of some of the original engineers who developed the car.

The idea behind this project was to convince Ford management that the company could compete with the Dodge Viper and other exotics, many of which were powered by V10 engines.

Another part of the company was already working on the 2005 GT behind closed doors, and it was hoped both projects could merge.

Ford already had its own V10 powerplant, but this was a heavy-duty truck engine tuned for trailer-towing low-end torque rather than drag-strip high-rpm performance, featuring an iron block and a 6.8L displacement.

Therefore, the engineers worked, mostly after hours and without much budget, to develop a new V10 engine that would be fit for a supercar.

The result was an all-aluminum, 5.8L (351 cu in) short-stroke V10 engine that was essentially a standard Mustang 4.6L V8 with the addition of two cylinders.

The cams and cam covers were made using the same moulds as those used in the then top-of-the-line V8-powered Cobra R, and so were the pistons.

The crankshaft was unique to this engine, making it odd firing instead of the truck V10’s even firing order.

This prevented the use of the company’s usual EEC-V engine control module, which couldn’t manage an odd-firing V-10. Instead, the engineers used a separate EEC-V computer for each cylinder bank, as the ECU could run an inline-five cylinder.

The team also had to fabricate a number of parts that didn’t exist in the company’s parts bin, such as the oil pan and the intake manifold, which is a heavily reworked variant of the Cobra R item.

Using the 4.6L V8 as a starting point for this V10 meant the engineers could use the same mounting points for the engine, limiting the modifications that had to be made to the body shell.

In addition, the addition of two cylinders only added about 4-inches of length to the front of the engine, and the use of aluminum instead of iron meant the 10-cylinder was 60 pounds lighter than the 5.4L V8 used in the Cobra R.

Once the engine was complete sometime in 2002, the engineers found a silver 1999 Mustang coupe that had served as a test mule for the Cobra R, which entered production in 2000.

The prototype V8 engine was replaced by the new experimental V10, and loads of performance monitoring computers were fitted to help the engineers gather data.

In the fall of 2003, this V10 Mustang, badged Boss 351, was tested by Hot Rod Magazine at the Milan Dragway in Michigan. The best quarter-mile time achieved that day was 11.51 seconds at 118.18 mph (190.19 km/h) on race tires and 12.28 seconds at 117 mph (188.29 km/h) on street tires.

This made the prototype faster than any road car on the market at the time. By comparison, a contemporary supercharged Mustang Cobra could manage 12.83 seconds at 110 mph (177 km/h).

Despite this achievement, Ford’s management decided on a new V8 engine for the 2005 GT rather than a production version of the experimental V10, which relegated the prototype to obscurity.

Almost twenty-five years later, the Ford heritage fleet brought the car back to working order alongside some of the people who created it, marking the end of their recommissioning work with a celebratory dyno run.

Almost a quarter century after having been fabricated using a hodgepodge of parts by a small team of dedicated engineers operating on a shoestring budget over nights and weekends, the 5.8L V10 still produces over 510 horsepower at the wheels.

Now, this unique part of Ford’s history will continue to be preserved, this time as part of the company’s heritage fleet rather than as a forgotten artifact in a closed garage.

Source: Ford and Hot Rod Magazine