The Audi R8 is a sports-prototype race car introduced in 2000 for sports car racing as a redevelopment of their Audi R8R (open top LMP) and Audi R8C (closed top LMGTP) used in 1999. It is one of the most successful sports cars ever (alongside such greats as the Porsche 956/962) having won the prestigious 24 Hours of Le Mans in 2000, 2001, 2002, 2004, and 2005 (five of the seven years it competed). A streak of six straight Le Mans victories was broken-up only by the Bentley Speed 8 (a sister design) in 2003, when the R8 finished 3rd.
The gasoline-powered Audi R8 race car was replaced by the new Audi R10 TDI Diesel in 2006; however, the need to further develop the R10 meant that the R8 saw action in a few races leading up to Le Mans.
With the upcoming American Le Mans Series also providing a stage for the US-market, Audi announced plans in 1998 to compete in 1999, with a car called R8 and powered by a V8 turbo. As it was considered the better choice for a whole race due to less weight and wider tires, Audi ordered an open top roadster from Dallara, to be developed and run by Joest Racing.
Yet, during the fall of 1998, after the necessity of GT1 homologation was dropped in favour of LM-GTP prototypes, regarding the speed and success of these closed GT coupés like the Porsche 911 GT1, Mercedes-Benz CLK-GTR, and the Toyota GT-One, Audi also ordered their newly acquired Norfolk based RTN (Racing Technology Norfolk, led by Tony Southgate) to build a closed-cockpit car using the same drivetrain.
The ACO rules for closed-top prototypes allowed cars to run with larger air restrictors, resulting in more power (about 600 hp), which resulted in a higher top speed in combination with the lower drag. To compensate this advantage over the duration of a race, the LMGTPs were limited to smaller tires and smaller fuel tanks.
After further tests and modifications, the Audis returned for Le Mans. The new debuting R8Cs lacked pace and unfortunately suffered mechanical gearbox woes. Lap times were 10 seconds down from the leading LMP and LMGTP competitors. Joest's R8Rs ran steady, yet still was too slow to run for pole position. After a race which saw the spectacular flights of the Mercedes-Benz CLR as well as leading cars of Toyota and BMW crashing out, the Audi R8R took 3rd and 4th behind the surviving #15 BMW and the Japanese-driven Toyota.
Based on the experiences, Audi decided to regroup for 2000, and built a new R8 roadster together with Joest and Dallara. The British-built R8C GTP was retired, but Audi-owned Bentley developed the concept of the R8C closed cockpit LMGTP and entered the Bentley EXP Speed 8 in 2001, eventually leading to success in the future.
This left only Porsche as a major possible challenger for 2000 — however the Porsche LMP project was scrapped before it had a chance to race. Rumors at that time said that Ferdinand Piech himself made them stay away, using his influence as a co-owner of Porsche as well as his management role at Volkswagen, which would develop the upcoming SUV VW Touareg in cooperation with the Porsche Cayenne . The Porsche V10 racer was turned into the Porsche Carrera GT instead.
The Audi R8 was the only car until today to have beaten the 1999 Toyota GT-One's Le Mans record qualifying lap in 1999 (3:29:930) with a time of 3:29:905 in 2002. This proved the R8 to be the fastest LMP category car around the circuit.
The R8 won a hat trick at Le Mans (three wins in a row) campaigned by Audi Sport Infineon Team Joest and driven by Tom Kristensen, Emanuele Pirro and Frank Biela during the 2000-2002 seasons. First time out in 2000, the team won a 1-2-3 finish, which was just a small preview of what this all-new Audi was capable of. Since then, the Audi R8 has won numerous championships and races, including wins at Le Mans in 2004 and 2005.
The R8 is powered by a 3.6 L twin-turbocharged and intercooled Audi FSI V8. FSI stands for Fuel-Stratified Injection, which is a variation on the concept of gasoline direct injection developed by VW which maximizes both power and fuel economy at the same time. FSI technology can be found in products available to the normal public, across all brands in the Volkswagen Group.
The power supplied by the R8, officially listed at about in 2000, 2001 and 2002, in 2003 and 2004 and in 2005, is sent to the rear wheels via a Ricardo six-speed sequential transmission with an electro–pneumatic gear change. That means it has a computer-controlled clutch that allows the driver to make gear changes without touching the clutch pedal. These gear changes can be done by the computer far quicker than even the fastest human being with a conventional manual transmission.
Unofficially, the works-team Audi R8 for Le Mans (2000, 2001 and 2002) is said to have had around instead of the quoted . The numbers were quoted at speed, and were due to the car making 50 extra horsepower due to twin ram-air intakes at speeds over 150mph. Official torque numbers were quoted for this version of the engine at 516 Lb.Ft@6500rpm. The equation for horsepower (torque divided by 5250, multiplied by rpm) for these numbers produces a horsepower rating of 638 horsepower at the same 6500 rpm (516/5250*6500=638). Peak rpm for horsepower was 7200, so it can be safely said that the engine made much more than 610HP in those years.
However, while the R8's speed was quite dominant during the races, speed is but a minor factor in winning the 24 Hours of Le Mans. The main key is reliability. The R8 was a reliable car, yes; but not far more so than its competitors. The real reason for the R8's dominance at La Sarthe was its ingenious design.
The Audi R8's structure was designed from the very beginning to expedite parts changes during the race. The car has a chassis that has been likened to a Lego model — anything on the car can be changed and changed quickly. During its campaign, the Joest pit crew was able to change the entire rear transaxle of a damaged R8 — a process which usually takes between one and three hours — in three and a half minutes, a feat that was unprecedented in its efficiency and speed. The reason for this was that the transmission, rear suspension and rear subframe were built as one unit. The car had numerous quick-connect hoses and easily removable bolts. The whole rear section of the car could be removed as a whole and a new back half installed with the help of a crane. The Automobile Club de l'Ouest (ACO), organizers of the 24 Hours of Le Mans and the American Le Mans Series acted quickly to void this advantage by mandating the gearbox casing be the same item through the duration of the race, with only the internals being allowed to be changed. However, the R8 still had quicker access to the gearbox internals than any other car due to its quick-change construction . This was critical as the gearbox was the weak link in the car.
The R8's structure and body are both composed of carbon fiber, a strong, lightweight polymer material that is both expensive and time-consuming to mold.
Performance - from top speed to acceleration - was, as in most race car cases, variable depending on the car's setup. The highest speed of the R8 at Le Mans was in the practice sessions of the 2002 Le Mans 24 Hours Race. A low downforce setup could generate about 350 km/h (217 mph).
Audi Sport's program saw tragedy in 2001 when on April 25, popular driver Michele Alboreto died in an accident after suffering a high-speed tire failure during an R8 test session at the Lausitzring in eastern Germany .
† - Season partially run by the Audi R10 as well.
Emanuele Pirro, Frank Biela and Marco Werner made history by becoming the first drivers to win the Le Mans 24-hour race in a diesel-powered car. The Audi R10 TDI completed a record 380 laps of the La Sarthe circuit, with Pirro at the wheel for the finish. French trio Sebastien Loeb, Eric Helary and Franck Montagny took second in the Pescarolo Judd No 17, four laps adrift. Scotsman Allan McNish was third in the other Audi, which came in 13 laps down after suffering mechanical problems.
The venerable R8 continued to campaign the American Le Mans Series through the first half of the 2006 season, and made its final US appearance on July 1, 2006 at Lime Rock Park, Connecticut, piloted by McNish and Capello. The R8 ended its career in style by winning the race, the 50th American Le Mans Series win for the Audi R8. The R10s participated in the rest of the ALMS season, beginning with the race at Miller Motorsports Park, Utah.