Supercharged Mustangs weren’t always a regular sight on our roads or racetracks. Early power upgrades to the iconic Mustang usually consisted of smaller, internal modifications to Ford’s legendary V8, and were often suited to motorsport.
The Mustang’s competitiveness at racing events around the globe caught the eye of renowned engineers like the Texan-born Carroll Shelby who, under his company Shelby American, spent time developing a supercharger conversion to enhance the Mustang’s existing characteristics and sporty persuasion. His dedicated work soon yielded a powerful combination that cemented Carroll’s reputation beyond that of a racing driver and endeared him to all muscle car enthusiasts.
It is on this annual Global Mustang Day, 17 April, that Ford South Africa chooses to honour 55 years since Carroll Shelby, in 1966, produced the first commercially available supercharged Mustang: the iconic and sought-after Shelby GT350 Fastback.
Fitted with a Paxton supercharger that forced increased airflow through the factory 460-cfm carburettor, Shelby claimed that power was 46 percent higher compared to models without the supercharger. What made the claimed 0-100km/h time of under six seconds and a top speed of over 240km/h even more impressive was that the Mustang retained the standard four-speed gearbox and very few other modifications were needed to cope with the extra power. However, to demonstrate the significant gains beyond all doubt, Carroll Shelby arranged a drag race between the GT350 and a Shelby Cobra Roadster. When the GT350 won in convincing style, Carroll Shelby placed an order of 500 Paxton superchargers and defined the Mustang and Shelby partnership.
This enticing and straightforward power upgrade could be done at the customer’s request, but the car’s rarity was ensured by the fact that only eleven of these were sold. The remaining supercharger kits were sold separately and over the counter.
These unique GT350s didn’t only feature an upgraded engine; motorsport-inspired gauges for manifold pressure and vacuum pressures were fitted below the centre instrument panel. Another highlight was the glovebox which included Carroll Shelby’s autograph, starting a tradition that still exists on the latest Shelby models like the Super Snake, GT-H and 2021 Speedster convertible.