Circuit de la Sarthe

The Circuit de la Sarthe, located near Le Mans, France, is a semi-permanent race course most famous as the venue for the 24 Hours of Le Mans auto race. The track uses local roads that remain open to the public most of the year. The circuit, in its present configuration, is 13.629 km (8.469 mi) long, making it one of the longest circuits in the world.

Le Mans is a race where up to 85% of the time is spent on full throttle, meaning immense stress on engine and drivetrain components. However, the times spent reaching maximum speed also mean tremendous wear on the brakes and suspension as cars must slow from over 200 mph (322 km/h) to around 65 mph (105 km/h) for the end of Mulsanne in a short distance. Downforce in the era of Group C cars helped braking to some degree but presently cars are tending towards low downforce to seek higher speeds in the face of power limiting regulations.

Track modifications
The track, which basically was a triangle from Le Mans down south to Mulsanne, northwest to Arnage, and back north to Le Mans, has undergone many modifications over the years, with CIRCUIT N° 14 being in use since 2007. In the 1920s, the cars drove from the present pits on Rue de Laigné straight into the city, and after a tight right-hander near the river Sarthe Pontlieu bridge, left the city again on the rather straight street now named Avenue Georges Durand after the race's founder. Then 17.261 kilometres (10.725 mi) long and unpaved, a bypass within the city shortened the track in 1929, but only in 1932 the city was bypassed when the section from the pits via the Dunlop Bridge and the Esses to Tertre Rouge was added. This classic configuration was 8.369 miles (13.469 km) long and remained almost unaltered even after the 1955 tragedy. The pit area was modified at a cost of 300 million francs, but race track and pits were not separated for another two decades. The signalling area was even moved to the exit of the slow Mulsanne corner. With cars getting ever faster in the 1960s, criticism rose, especially when several drivers were killed, often in the testing session in April. Since 1965, a smaller but permanent Bugatti Circuit was added which shares the pit lane facilities and the first corner (including the famous Dunlop bridge) with the longer version. For the 1968 race alone, the Ford chicane was added before the pits to slow down the cars. The circuit was fitted with Armco for the 1969 race. The purpose built Porsche Curves section bypassed the dangerous and fast Maison Blanche kink between buildings in 1972.

Le Mans was most famous for its 6 km (3.7 mi) long straight, called Ligne Droite des Hunaudières, a part of the route départementale (for the Sarthe département) D338 (formerly Route Nationale N138). The Targa Florio featured the even longer Buonfornello straight along the coast, though. As the Hunaudières leads to the village of Mulsanne, it is often called the Mulsanne Straight in English, even though the proper Route du Mulsanne is the one to Arnage. The Porsche 917 long tail had reached 380 km/h, but after engine size was limited, the top speed dropped until the Group C allowed powerful turbo engines. Speeds on the straight reached over 400 km/h (250 mph) during the late 1980s, and the combination of high speed and high downforce caused tyre failures. Due to safety concerns two roughly equally spaced chicanes were consequently added to the straight before the 1990 race to limit the achievable maximum speed. In 1990 FIA decreed that it would no longer sanction any circuit which had a straight longer than two kilometres. The fastest qualifying lap average speed dropped only from 249 to 243 km/h in 1993, and it rose up to 247 in 2008, not far from the all time best of 250 and 251 set by the Porsche 917 and 956. Regarding the lap record in the race itself, 2008 saw the fastest ever.

Bugatti Circuit
Bugatti Circuit is a race track located within Circuit de la Sarthe, named after Ettore Bugatti. The circuit uses a part of the larger circuit and a separate, purpose-built section. The sections of track on the Bugatti Circuit that are on the Circuit de la Sarthe include the Ford Chicane at the end of the lap, the pit complex, and the straight where the Dunlop Tires bridge is located. At this point in the overlapping section of the tracks there is a left right sweep that was added for motorcycle safety in 2002. Vehicles turning to the left continue onto the Circuit de la Sarthe, toward Tertre Rouge and Mulsanne, vehicles turning to the right will continue the Bugatti Circuit.

The track is home base for Pescarolo Sport, founded by famous French driver Henri Pescarolo. The circuit also hosts the 24 Hours of Le Mans motorcycle race, and a round of the MotoGP Championship. The circuit also holds French motor club races and in the past has hosted a round of the DTM (German Touring Car series).

As well as motor racing it is the venue for the 24 rollers, a 24h race on inline skates or quads.

The track was used for the 1967 French Grand Prix.

Speed record
In 1988, Team WM Peugeot knew they had no chance of winning the 24 hour endurance race, but they also knew that their Welter Racing designed car had very good aerodynamics. Thus they nicknamed their 1988 entry "Project 400" (aiming to be the first car to achieve a speed of 400 km/h on the famous straight), although the official team entry was named WM Secateva. Roger Dorchy, Claude Haldi and Jean-Daniel Raulet would be the three drivers that year.

The Peugeot 2.8L V6 turbo charged PRV engine had its air intakes taped over to improve aerodynamics, and they also equipped the car with special narrow Michelin tires. The plan worked: with Roger Dorchy behind the wheel, the WM P87 achieved the speed of 407 km/h (252.9 mph).

Taping over the air intakes obviously impeded engine cooling, and the Peugeot was only the third Group C1 car to exit the race after 59 laps with an overheating engine.