Porsche 911 GT1

The Porsche 911 GT1 was a racing car designed for competition in the GT1 class at the 24 Hours of Le Mans and sold as a road car for homologation purposes. The roadgoing version was labeled the 911 GT1 Straßenversion.

History
Porsche debuted the 911 GT1 in 1995, announcing that it would compete at the 1996 24 Hours of Le Mans. In spite of its name, the car actually has very little in common with the 911, its floorpan was taken from the Porsche 956|956/962 Group C car. In addition, the GT1 featured a water cooled, twin-turbocharger|turbocharged and intercooler|intercooled 3.2 L, multivalve|four valve per cylinder flat-six in a MR layout|mid-mounted position and making about 600 horsepower. In comparison, the Porsche 993|993 generation Porsche 911 GT2|911 GT2, which was otherwise the company's highest-performance vehicle, used an air-cooled engine with only 2-valves per cylinder and mounted in the rear, which is the traditional layout for the 911.

1996
The new vehicle was an outright success at Le Mans, winning the GT1 class at its debut race, although it lost the overall victory to Joest Racing's TWR-Porsche prototype, still a success in that this vehicle used a Porsche powerplant.

The 911 GT1 made its debut in the BPR Global GT Series (the FIA championship's predecessor) at the last race of the 1996 season, in Zhuhai, although the organisation was reluctant to accept the car and did not allow it to score points. Emmanuel Collard and Ralf Kelleners won outright without much contention.

1997
In 1997, the new Mercedes-Benz CLK-GTR was successful in the new FIA GT Championship that replaced the BPR, as it was developed for racing. Mercedes did not enter Le Mans yet with their new car, though. The Porsche did not prove to be as fast in the FIA series, and failed to win a single race, first against the McLaren F1 GTR, and then against the new CLK-GTR.

Porsche made minor revisions to the car for the 1997 Le Mans, including restyling the front end to incorporate "kidney shaped" headlamps like what would appear a year later on the 996 generation 911s, and Boxsters; this version is known as the 911 GT1 Evo (or Evolution). However, the works cars suffered from reliability problems and did not last the full race distance; a privately entered GT1 managed 5th overall and third in its class, but was beaten by the BMW-backed and powered McLaren F1 GTRs.

1998
Porsche committed themselves to a full blown re-thinking of the vehicle for the 1998 race, as the FIA and ACO abandoned the rule that GT1 cars must be based on a production vehicle. Designed to match the Toyota GT-One and Mercedes CLK-GTR, the 911 GT1 '98 featured radical changes to the bodywork and a new sequential gearbox. In 1998, in spite of improvements to the car, the privately entered Porsches proved to be no match for the works CLKs which also were improved. This was also due to the air-restrictor rules being regarded as unfavourable to the turbo engine. The Michelin tyres of the factory team and especially the Pirelli of Zakspeed were considered inferior to the Bridgestone of Mercedes, which also would dominate in F1 for many years.

At Le Mans, it was a different story. The new BMW V12 LM retired with wheel bearing trouble, and the Mercedes CLK-LM vehicles had oil pump troubles in the new V8 engines that replaced the former V12. The Toyota GT-One was very fast but also unreliable.

The revised 1998 model, despite being slow, fulfilled Porsche's slim hopes, taking both first and second place overall thanks to reliability, giving Porsche its record-breaking 16th overall win at Le Mans, more than any other manufacturer in history.

At Road Atlanta, the 911 GT1/98 of Yannick Dalmas made a spectacular backward flip, as did the BMW V12 LMR at the same place in 2000, and most famously the Mercedes-Benz CLR at Le Mans in 1999.

1999
With Mercedes dominating FIA GT1 in 1998, all other entries including Porsche withdrew for 1999. The GT1 class was cancelled, and the FIA GT Championship was contested with GT2 cars. Porsche could have entered at Le Mans, but chose not to try to defend the lucky win of '98 against new machines from other factories.

Champion Racing brought a 911 GT1 Evo to America to race in the American Le Mans Series, but was only allowed to do so as a LMP (Le Mans Prototypes) class entry, where it proved uncompetitive against actual prototypes such as the BMW V12 LMR.

The road version
Regulations for the GT1 category stipulated that to be eligible, a total of 25 cars must be built for road use. Porsche developed a fully road-legal version of the GT1 and delivered one in early 1996 to the German government for compliance testing, which it passed. The engine had to be slightly de-tuned to meet European emissions laws, although its 544 PS (400 kW) and dry weight of 1,100 kg proved to be more than adequate; the vehicle could accelerate to 100 km/h (62 mph) from a standstill in 3.5 seconds on its way to a top speed of 310 km/h (193 mph).