AMR-One prototypes sidelined in Le Mans 24 Hours

14 Jun 2011

Although Aston Martin Racing was openly treating last weekend’s Le Mans 24 Hours race as purely another test session for its new AMR-One sports-prototype, fate cruelly intervened to deny the team even that.

After running without problems in the final qualifying sessions on the Thursday before the race, both sports-prototypes suffered from water pump failure induced overheating following a precautionary pre-race change of the pulley driving the pump: first number 007, with Darren Turner at the wheel, locked its wheels as a result, spinning into a gravel trap on only the second lap, before eventually limping back to the pits; then on the following lap Adrian Fernandez in 009 similarly succumbed and was forced into immediate retirement. It marked a miserable and early end for Aston Martin’s return to the French classic.

The two Astons, driven respectively by Christian Klien/Stefan Mucke/Turner and Fernandez/Andy Meyrick/Harold Primat, had qualified in 22nd and 25th places overall and 15th and 17th in the top 17 car LMP1 class, but no fewer than some 13 seconds off the pace of the petrol-fuelled cars. Encouragingly, though, despite running some ten per cent down on maximum power – the 2.0 litre turbocharged, straight six cylinder, engine should produce 525 to 530bhp (under the new for 2011 regulations petrol cars can run either 3.4 litre normally aspirated or 2.0 litre turbo’ engines, and diesel cars 3.7 litre turbo’ units, all supposed to produce around 520bhp) – the drivers of Peugeot’s front-running 908 diesel-fuelled cars reported that they couldn’t touch the AMR-Ones through some of the corners, such is the Aston’s excellent chassis balance.

As for the cooling system failure, this resulted after a small crack was discovered in the belt-driven aluminium pulley that propels the gear-driven water pump. New pulleys were made in steel and fitted but the different and untried material increased both weight and momentum which proved too much for the water pump gears. Once 007 had reached its pit garage frantic work ensued to replace the offending item with an original aluminium pulley, which necessitated removing the engine; over two hours later 007 rejoined the race only for Mucke to return one lap later and ultimately retire, the earlier overheating having caused terminal engine damage.

While such a relatively minor event as changing the pulley thwarted any hopes Aston Martin Racing had of finishing the race and making some headway through the field, it is at least another lesson learnt in these still early days of the AMR-One. Slow in its gestation, its very limited testing directly correlates to Aston Martin’s vastly limited budget compared to the likes of Peugeot and Audi, the latter this year taking its tenth Le Mans win. Unveiled in September last year and the first all in-house sports-prototype since the AMR1 of 1989, the latest in a long and illustrious line of Aston Martin race cars only got the go-ahead once Le Mans organiser the Automobile Club de L’Ouest had formally committed to finally resolving the long disputed disparity between petrol and diesel-fuelled cars.

This late start was compounded by the until then secret new engine – the straight six configuration is central to both the AMR-One’s design and its aerodynamic packaging – not running before January this year. It was then almost mid-March before the car’s maiden run on the test track, followed by further testing at Snetterton and Dijon. The Aston’s race debut – but still very much a test session, described as a ‘test race’, and with power output well down while awaiting new engine components – came two days after the Dijon test at Paul Ricard for the Le Castellet Six Hours, the first round of the 2001 Le Mans Series. Although some five seconds off the top LMP1 qualifying pace, the sole AMR-One did complete the race and then remained at the circuit for more testing.

Despite the ACO promising that this year, at last, there would be parity in 2011 between diesel and petrol fuelled LMP1 prototypes – the main criterion that persuaded Aston Martin to build an all-new car conforming to the 2011 regulations – the oil-burning cars of Audi and Peugeot remain disappointingly dominant. At the previous round to Le Mans, the Spa 1,000 Kilometres, the fastest of these in qualifying was 5.2 seconds quicker and in the race the winning Peugeot was 4.8 seconds quicker than the fastest petrol machine, the Pescarolo-Judd, in sixth place. The ACO duly reacted in advance of criticism by changing the regulations to reduce the deficit: smaller fuel capacity for the diesel cars and an increase in induction air restrictor size for the petrol machines.

Serious doubts, however, that these adjustments would be sufficient were fully realised by the end of the qualifying sessions of the 24 Hours: the fastest petrol-fuelled car was a full 7.1 seconds adrift of the pole position Audi, while the two other works German cars and the trio of works Peugeots immediately behind all qualified within just over half a second of each other; in the race, the best lap, by the winning Audi, was 11.2 seconds clear of the fastest petrol prototype lap by the Rebellion Racing Lola-Toyota that finished in sixth position. Plus ça change.