|Audi R8 LMP|
The Audi R8 is a Sports Prototype race car introduced in 1999 for Sportscar racing as a redevelopment of their Audi R8R (open top LMP) and Audi R8C (closed top LMGTP). The 2000 and later version Audi R8 was very successful, winning many races and championships until it was retired during the 2006 season. It is considered by some to be 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. A streak of six straight Le Mans victories was broken-up only by the Bentley Speed 8 in 2003, when the R8 finished 3rd.
The gasoline-powered Audi R8 race car has been replaced from 2006 onwards by the new Audi R10 Diesel, however, the need to further develop the R10 has meant that the R8 has seen action in a few races leading up to Le Mans.
1998: The challenge
In 1997, sports car racing and especially the Le Mans 24 Hours was popular among factories like BMW, Mercedes-Benz, Porsche, Toyota, Nissan Motors and others. At that time, Audi Sport boss Wolfgang Ullrich started to evaluate the options of joining.
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 550 hp V8 turbo. As required by the rules it had simple RWD drive, which was a kind of surprise as Audi used to insist on its quattro all-wheel drive in touring car racing, or else stay away at least as a factory entrant.
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, similar to their Le Mans-Winner of 1996 and 1997 as well as to the 1998 BMW V12 built by WilliamsF1 (which would go on to win in 1999).
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 Porsche 911 GT1 ('98 Le Mans Winner), the Mercedes-Benz CLK-GTR ('98 FIA GT champion, beating the 911 GT1 in all GT races) and the Toyota GT-One (considered fastest), Audi also ordered their newly acquired Norfolk based RTN (Racing Technology Norfolk, led by Tony Southgate) to build such a 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 GTPs were limited to smaller tires and smaller fuel tanks.
1999: The R8R and R8C
At the 1999 12 Hours of Sebring, two R8R cars showed up, painted in silver, to revive the 1930s Silver Arrow rivalry with Mercedes — which was absent, as was Toyota and the brand new closed-roof R8C which needed to be tested first. Also, Porsche took a year off to develop a V10 car.
After further tests and modifications, the Audis returned for Le Mans, with the R8C only looking fast, even while standing still in the RTN pits, which it did too often. Lap times were 10 seconds down, too. Joest made their cars run steady, yet still was too slow to run for P1. 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 Bentley developed the concept and entered the Bentley Speed 8 at the 2001 event, and after more work again in 2003, this time as a winner.
1999: Retiring competitors
After the 1999 Le Mans shame, Mercedes retired from GTs to focus on the return of the DTM touring cars in 2000, as well as on F1. Toyota and BMW also went to F1, with BMW at least continuing to race for two years in the ALMS, where the open roadster of Bill Auberlen also suffered a "back flip" during the Petit Le Mans at Road Atlanta in 2000, as the closed-cockpit Porsche of Yannick Dalmas had done in 1998. Despite the BMW V12 not receiving further development, the German team Schnitzer Motorsport was almost as effective as Joest. They returned to race BMW M3 touring car since, dominating in the ALMS and in WTCC as well as at the 24 Hours Nürburgring.
This left only Porsche as a major possible challenger for 2000 — which never showed up, though. Rumors at that time, which where confirmed since, said that Ferdinand Piech himself made them stay away, using his influence as a co-owner of Porsche as well as his manager positions 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.
2000: The R8
The Audi R8 is a sports-racing car prepared for sports car racing in the LMP900 class at Le Mans and in the American Le Mans Series. The car was developed by Audi Motorsport and Joest Racing and first debuted in 2000, winning the 12 Hours of Sebring.
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 limited to about 580 hp (about 430 kW) during the 2004 race, 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.
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 four and a half minutes, a feat that was unprecedented in its efficiency and speed. 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.
The R8's structure and body are both composed of carbon fiber, a lightweight polymer material which is extremely lightweight and strong; however it is very expensive and time-consuming to mould.
Audi Sport's programme 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 RB test session at the Lausitzring in eastern Germany.
2003: Bentley Breaks the Streak
It should be noted, however, that the Bentley Speed 8, which ran at Le Mans from 2001 to 2003, winning in 2003, utilised a heavily modified 4.0 L version of the turbocharged V8 engine from the Audi R8. The Bentley racing effort was campaigned by Team Bentley (Apex Motorsport) with assistance from longtime R8 competitor Joest Racing and Audi Sport UK. Tom Kristensen, who won the previous three 24 Hours of Le Mans races in an R8, was assigned to drive the Bentley Speed 8, and helped guide the team to victory. (Kristensen went on to win the 2004 and 2005 races in an Audi R8). Some even say that the works Audi teams sandbagged the race in order to hand victory to the Volkswagen/Audi Group's newest addition, Bentley Motors. There is also some similarity between the Bentley Speed 8 and the Audi R8's successor, the R10. In some places the Bentley is referred to as being the R9.
2005: The end of a legend
Very few racing cars have a racing pedigree comparable to the R8. However, as amazing as the R8 was, during the 2005 season, it was evident that its time at the front of the pack was drawing to a close. Audi had made the development of the R10 diesel public, and cars from other manufacturers and teams started to catch up in terms of on-the-track speed. The ACO still felt that the R8 needed to be kept in check, therefore they reduced the restrictor size on the R8's engine and stipulated the car shall carry ballast in an attempt to make the races more competitive. At the 2005 Le Mans, the Audis failed to qualify on pole position; the fastest R8 started the race in third position. However, as a hallmark to the R8's legendary reliability, the car was able to outlast all other competitors to take its fifth checkered flag at the venerable Circuit de la Sarthe and the 24 Hours of Le Mans. This victory was also notable since it was Tom Kristensen's 6th straight 24 Hours of Le Mans victory, and a record 7th overall, beating legendary driver Jacky Ickx's previous record of 6 career 24 Hours of Le Mans victories.
2006: the R10 Diesel
In response to the new level of competition, development of the successor, known as the Audi R10, has been completed. The V12-Turbodiesel won at its race debut at the 2006 12 Hours of Sebring with both cars starting on the front row. Unfortunately the pole sitting R10 had to start from the pit lane due to the need to rectify heat exchanger issues. Peugeot is expected to build a Diesel powered rival in 2007. 
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 Diesel 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 will participate in the rest of the ALMS season, beginning with the next race at Miller Motorsports Park, Utah.
2007: the R8 Road Car
The name Audi R8 will also be used by the future production road sports car/supercar Audi R8 Road Car which will be based on the 2003 Audi Le Mans Quattro concept car, not the R8 race car. Audi has announced that this car will be built in 2007 or later.