Mazda RX-8 completes 24-hour torture test

Mazda out to prove rotary reliability

Mazda is cock-a-hoop about the fact that its rotary-engined cars have completed a 24-hour endurance test. Rotary engines have in the past been noted for their fragility and high fuel consumption.

At the beginning of this month a 14-strong team of motoring journalists from 11 European countries, as well as Formula Woman champion Natasha Firman, put two Mazda RX-8s through 24 hours of non-stop maximum speed around the 7.6 mile banked circuit at Papenburg test facility, near Hamburg in Germany.

Under the auspices of the FIA, motorsport's official governing body, the German motorsport federation DMSB, selected two Mazda RX-8s for the event. The first was a standard road car and would compete in Category B for standard production cars. The other entrant was one of the cars used in this year's successful Formula Woman all-woman race series, competing in Category A for special vehicles.

Both cars were fitted with a bespoke racing seat, a full roll cage and fire extinguishers – all mandatory requisites for competition racing – but their mechanics were left untouched. The FIA even sealed the engine and gearbox to ensure its mass-produced authenticity. The race team was also supported by tyre manufacturer Kumho which supplied dry and wet weather tyres for the event, and German fuel supplier Aral provided on-site refuelling for the pair of Mazda RX-8s.

The cars started their ordeal at 12:20 pm on Saturday 3 October and, pausing only to refuel and change drivers, were pushed to their limits to create 40 new endurance records for naturally aspirated rotary-powered cars.

Under the hawk-like eyes of Shoji Tokuda, Mazda Motor Europe's chief engineer who tended to the cars' every needs throughout the 24 hour period, the pair of RX-8s racked up respective average speeds of 132.3 mph in the Group A section, and 134.1 mph in Group B, as well as an array of other time and distance records (see accompanying tables).

Mazda reckons the event underlines the bulletproof reliability of the Mazda RX-8. Each car covered a total of 3,174 miles during the 24-hour period without a blip from the Renesis twin-rotary engine.

The rest of the car was almost as fault free: a snapped boot release cable caused mass consternation in the pits because it meant one of the cars would be unable to refuel. But a bit of inspirational handy work with a mallet and a length of new cabling soon sorted the problem.

These records better those set by Johnny Herbert, Bertrand Gachot and Volker Weidler under race conditions during the 1991 Le Mans 24-hour endurance race. Their ferocious 700 bhp Mazda 787B racecar lapped the famous French circuit at an average speed of 127.1 mph.

But it’s not just about sitting in a car and driving at top speed around a big bowl. Papenburg's track is more lozenge-shaped – two long straights joined by a pair of sweeping, steeply banked curves at each end.

Despite driving flat out in sixth gear to maintain maximum speed, further precious seconds can be shaved off a single lap simply by positioning the car with millimetric accuracy into the entry of the corner and slingshotting it out the exit. Now, a second here and there on a lap may not sound much, but over 415 laps, that adds up to a lot of saved time and higher speeds.

Driver change-over times were also crucial, hence the flurry of activity when one of the cars came in to collect a new driver. The outgoing driver has to enter the pit area as quickly and safely as possible, position the car for refuelling, kill the engine, release himself from the four-point harness and then climb out. While the new driver gets strapped in, the car is refuelled, the oil level and tyre pressures are painstakingly checked, the headlamps and windscreen are cleaned and then the go paddle is flashed up and the race against time starts again. Throughout the entire race every move on either car was adjudicated by an FIA official to ensure the attempt met their stringent qualifications.

It's through the long dark night that the drivers really need to be at the top of their game, as Formula Woman ace Natasha Firman explains: "It's a lot easier when it's light because you can pick up your turning reference points and you have a sense of what's around you. At night though, all you have is what the headlamps pick up. It makes it difficult to focus on the corner ahead when you can't see it. And," she admits, "it can feel quite lonely out there because you feel really isolated from the action."

It didn't help when rain started. Just after midnight the skies opened, releasing a cold and persistent downpour. A combination of lights and flags brought the cars into the pits for a quick tyre change, the Kumho engineers swiftly lowering the car's tyre pressure to reduce the chance of aquaplaning. But fortune was smiling on the Mazda team because the rain lasted no longer than an hour and the cars were soon back up to full pace.

And they maintained this v-max speed for 24 hours, crossing the line just after noon on Sunday 3rd October, with Shoji Tokuda enthusiastically waving the chequered flag. "There's no tougher test than this," he said. "We can't think of a better example of the reliability, strength and power of the Mazda RX-8's Renesis engine than a round-the-clock race against time."

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