In an effort to improve top speed along the legendary Mulsanne Straight at the 24 Hours of Le Mans race, a number of enclosed, coupe variations were constructed using the leafspring chassis and running gear of the AC/Shelby Cobra Mark II. The most famous and numerous of these were the official works Shelby Daytona Cobra Coupes. Six were constructed, each being subtly different from the rest. AC Cars also produced a Le Mans coupé. The car was a one-off and was nearly destroyed after a high-speed tire blow-out at the 1964 Le Mans race. The car was qualified conservatively second in GT. The race started well with the AC, chassis number A98, maintaining its position in the top two in GT and even leading the class for a time. This was not to last as an act of sabotage (newspaper in the fuel tank) began to block the fuel filter. The car lost time until this was diagnosed and cleaned out.[citation needed] The car proceeded on at the predetermined conservative lap time and for the next stint remained trouble free. The car was able to match the Shelby Daytona's speed despite running a higher differential ratio (2.88 instead of 3.07) and a lower state of engine tune for reliability (355 hp instead of the Daytona's 385 hp). The third significant Cobra-based coupe was the Willment Cobra Coupe built by the JWA racing team. A road-going Shelby Daytona Cobra replica is being manufactured by kit-car companies Superformance and Factory Five Racing. These cars use Pete Brock's bodywork designs, scaled up to increase room inside, and newly designed spaceframe chassis, they are powered by Roush-built Ford Windsor (Sportsman) engines. The Superformance Shelby Daytona Coupe is the only modern-day vehicle recognized by Shelby as a successor to the original Coupes. Other road-going Shelby Daytona Cobra replicas include Daytona Sportscar from Australia.
