Although the Aston Martin DBR9 race car is designed to withstand Le Mans, it has a surprising amount in common with the DB9 road car – from the moment that the driver opens the door and fires it up.
The DBR9’s 5999cc V12 engine is based on that of the road car, as the GT1 rules demand. The block and cylinder heads, in fact, are exactly the same ones you would find if you pulled apart any road-going DB9.
The similarities continue from top to bottom. The rules require competition cars to share exactly the same roof panel and shut lines as the road cars they are based on. The DBR9 also uses the same bonded aluminium tub from the platform of the road car. The overall height is the same although the DBR9 sits much lower and is slightly wider. The door handles and rear lights are also standard.
The fixtures and fittings are stripped out in the pursuit of speed, but the designers have to work within certain limits as the Le Mans rules impose a certain minimum weight for each class of car which is currently 1150kg for the GT1 class.
If the car is still a bit quicker than its opposition – even while sticking to the minimum weight limit – the race organisers are allowed to add on success ballast, in order to even things out. And this is exactly what has happened to Aston Martin’s DBR9, along with its key rival, the Chevrolet Corvette who will both be running 25kg heavier that the minimum weight this year. The price of success is…more weight.
But not all the creature comforts disappear - in extreme competition they are more like essentials. Air conditioning is one of them. On a hot day, in-cockpit temperatures can exceed 40 degrees centigrade. With the drivers clad in fire proof underwear, race suits, helmet and gloves, it’s very easy for them to overheat and dehydrate. Air conditioning is ultimately safer, so to encourage its use this year the ACO have granted rules breaks for cars that run it – like the DBR9.
The DBR9 is restricted to 600 horsepower as the rules dictate while the road car puts out around 450bhp. The ultimate top speed is not hugely different: on the Mulsanne straight there would be less than 20mph between road and race car although with improved breaking and handling capabilities and reduced weight the DBR9 lap time at Le Mans would be significantly less that the road going DB9.
The fundamental handling characteristics are similar as well, as the DBR9 uses the same double wishbone suspension layout as the road car. Tyres are bespoke for Le Mans, tyre partner Michelin formulate rubber specifically designed for protracted high-speed running.
One other thing that Aston Martin’s road and race cars have firmly in common is the fact that they are both hand-built. Each DB9 takes over 200 man hours to build in the factory in Gaydon, Warwickshire. The race car, assembled by Aston Martin Racing, takes somewhat longer – but the same attention to detail is evident in both.