In a period of ten years, Riley & Scott has grown out to be one of American leading chassis manufacturers. It all started in 1990 with the Mk I Trans Am car chassis and since then successes were scored in most major American road-racing championships. Introduced halfway through the 1990s, the Mk III sportscar proved to be the finest product of the Indianapolis based manufacturer. Together with the Ferrari 333 SP, the Mk III was the most successful prototype racer of the 1990s.
The design of the Mk III was very conventional, with a monocoque constructed from a combination of carbon fibre and steel. Double wishbones, with push-rod actuated dampers all-round took care of the suspension. It was this simple but effective design that made the Mk III the ideal customer chassis. Over its career a multitude of engines were installed, including the quad-cam Oldsmobile Aurora V8 and the pushrod Ford V8.
In close to 90 entries, over 40 victories were scored, including victories in legendary races like the Daytona 24 Hours. With the factory focussing on the Cadillac prototype project in 1999 and 2000, the development of the chassis was halted. This did not stop the customers from racking up victories on both sides of the Atlantic. For 2001, R&S concentrated on the Mk III again and launched a revised C-type chassis.
Although most modifications were carried through under the skin, the most noticable changes were on the nose of the car. The square headlights were replaced by more aerodynamic looking round units. A new front splitter was also installed. To lower the centre of gravity, the engine could now be mounted slightly lower in the chassis. A double/single roll-hoop option made it comply with the various sportscar racing series.
The modifications were an obvious improvement, but it was not enought to break Audi's stronghold in the American Le Mans Series or at Le Mans. The days of customer sportscar racing were once again coming to an end. There was no way that either R&S or its customers could match Audi's 8 figure budget. Rule changes in the GrandAm series for 2003, also meant the end of the car's active career in that series. Although no longer in the fight for victories, the Mk III C remains a worthy contender.
Like its nemesis, the Ferrari 333 SP, the Riley & Scott Mk III remained competitive throughout its relatively long career. Despite being the manufacturer's first sportscar design, it will go into history as one of the most successful racers ever.