late 1990s, where there was not really a commercially available road car. But the then secretary general of GTA, the governing body of Super GT, said that it was no problem and that we did not have to make a road car.’
CHASSIS CONUNDRUM With the path clear for Mooncraft to convert an existing Grand-Am chassis into a GT300 car, the next question was which chassis to choose as, in 2006, a number of chassis manufacturers came to the market. ‘To decide which chassis
to use we went to Daytona to choose the best handling car for our gentleman driver. That proved to be the Riley Mk XXII.’ With the chassis decided, the team turned its attention to the powerplant. To keep things simple, and to conserve the Riley’s handling and weight distribution, the choice was
restricted to those powerplants already utilised in Grand Am. ‘There was a range of engine choices and we chose the Lexus engine because it Japanese, of course!’ smiles Yura. ‘We had to modify the engine to take part in Super GT so it’s not completely the same as a Daytona Prototype
resulted in an output of around 350bhp for the engine in original trim, around 150bhp down on the versions used in the American series, though over the years the performance of the 4.4-litre V8 has been pegged back. ‘We also decided to carry over most of the suspension from the
“We chose the [Riley Mk XXII] chassis for its handling, so why change it?”
engine. The intake was made in house and, whilst the Daytona Prototype engine only has four butterflies, ours has one per cylinder. Also, to fit the Japanese specification for these races, we have a lot less power than a Daytona Prototype, because the restrictors are very small.’ This
Daytona Prototype. We chose this chassis for its handling, so why change it?’ says Yura. The six-speed sequential Xtrac transmission used by Riley was also carried over. After all the key components had been decided, Riley Technologies developed a revised
version of the Mk XXII at its new headquarters in Mooresville, NC. As is the case with the new third generation Daytona Prototype, the new chassis featured a standard Mk XXII lower chassis, but with a much narrower and lower ‘greenhouse’. The rolling chassis was then supplied to Mooncraft in Japan without a body. Yura’s team then set about developing a bespoke body for the car which, when it was first rolled out on track, drew admiring looks from all who saw it. But the body did more than look pretty. It was the absolute focus for Mooncraft’s engineers. ‘I couldn’t say how this car
would compare with a Riley because it is not polite to Riley!’ enthuses Yura. ‘The Daytona Prototype regulations have many restrictions about the aerodynamics, particularly cockpit
February 2012 •
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