With the revival of international sportscar racing in the mid-1990s through the BPR Global GT Series (which then morphed into the
FIA GT Championship) Porsche expressed interest in returning to top-level sportscar racing and went about developing its competitor for the GT1 category. Cars in this category were previously heavily modified versions of road cars, such as the
McLaren F1 and the
Ferrari F40. Porsche originally modified the
993 GT2 into an EVO version and homologated it as a GT1 car, but it proved to be uncompetitive against the other cars in its class.
911 GT1 Despite using the 911 moniker, the car barely had anything in common with the existing
911 at the time, only sharing the front and rear headlamps with the production sports car. However, its frontal chassis is based on the 993-generation 911, while the rear subframe was derived from the
962C Group C prototype along with its
water-cooled,
twin-turbocharged and
intercooled,
4 valves per cylinder
flat-six engine fuel fed by
Bosch Motronic 5.2 fuel injection, which was
longitudinally-mounted in a
rear mid-engine, rear-wheel-drive layout, compared to the
rear-engine, rear-wheel-drive layout of a conventional 911. The engine generated a power output of about . In comparison, the
993 generation
911 GT2, which was otherwise the company's highest-performance vehicle at the time, used an
air-cooled engine with only two
valves per cylinder. The 911 GT1 made its debut in the
BPR Global GT Series (the FIA championship's predecessor) at the Brands Hatch 4 hours, where
Hans-Joachim Stuck and
Thierry Boutsen won comfortably, although they were racing as an invitational entry and were thus ineligible for points. They followed up by winning at Spa, and
Ralf Kelleners and
Emmanuel Collard triumphed for the factory team at Zhuhai. The 1996 911 GT1 clocked at a top speed of exactly on the legendary
Mulsanne Straight in the practice sessions of the 1996 Le Mans 24 Hours Race.
911 GT1 Evo Towards the end of the 1996 season, Porsche made revisions to the 911 GT1 in preparation for the 1997 season. The front end of the car was revised including new bodywork which featured headlamps that previewed the all-new generation of the (
996) Porsche 911 which would be unveiled in 1997. The revised car was known as the
911 GT1 Evo (or Evolution). The car had the same engine as the 1996 version, but its new aerodynamic elements allowed the 1997 version to be considerably faster than the 1996 version with improved acceleration, the top speed was still around on the La Sarthe Circuit (in the race, the GT1 Evo attained a top speed of 326 km/h). At
Le Mans the works cars led the race but did not last the full distance; a privately entered 1996 specification GT1 managed 5th overall and third in the GT1 class.
911 GT1-98 For the 1998 season, Porsche developed an all-new car, the 911 GT1-98. Designed to match the also new
Toyota GT-One and the
Mercedes-Benz CLK LM, the 911 GT1-98 featured bodywork that bore more of a resemblance to traditional sports-prototypes than the previous two models. A new
sequential gearbox was installed to reduce shift time. Engine control also moved to a TAG Electronic Systems TAG 3.8 ECU. As per the regulations, a street-legal version of the 911 GT1-98 was made but it is believed that only one variant was produced which was still sufficient to satisfy the new regulations. During the 1998 FIA International GT season, the 911 GT1-98 struggled to match the pace of the Mercedes, which also was improved, with the main reason being down to the air-restrictor rules which were regarded as unfavourable to the turbocharged engine (the Mercedes had a naturally aspirated V8 engine). The
Michelin tyres of the factory team and especially the
Pirelli of the private
Zakspeed team were also considered inferior to the Bridgestone tyres of the Mercedes. At the 1998 Le Mans, however, it was a different story. The
BMW V12 LM retired with wheel bearing trouble, and the
Mercedes CLK-LM cars had oil pump troubles in the new V8 engines that replaced the former V12. The
Toyota GT-One, which was considered to be the fastest car, also suffered gearbox reliability problems. The 911 GT1-98, despite being slower than the Toyota or the Mercedes, 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 the
Petit Le Mans race in
Road Atlanta, the 911 GT1-98 of
Yannick Dalmas made a spectacular backward flip and landed rear first before hitting the side barriers, similar to what would later happen to a
BMW V12 LMR at the same race in 2000, and the
Mercedes-Benz CLR at Le Mans in 1999.
1999 With
Mercedes dominating
FIA GT1 in 1998, all other entries including Porsche withdrew for the 1999 season. The GT1 class was cancelled, and the FIA GT Championship was contested with GT2 cars. Having won the 1998 24 Hours of Le Mans, Porsche could have entered at
Le Mans, but they opted not to try to defend their 1998 victory against the new entrants from other manufacturers.
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 an LMP (Le Mans Prototype) class entry, where it proved uncompetitive against actual prototypes such as the
BMW V12 LMR.
Gunnar G-99 Following Champion's purchase of a 911 GT1 Evo for 1999, Gunnar Racing offered a custom race car to the team with intentions to race in 2000. The car, known as the Gunnar G-99, was a custom-built 911 GT1 with an open cockpit. The chassis was made from scratch yet remained nearly identical to the 911 GT1 mechanically, even using the bulk of the body parts. A large rollbar was put over the open cockpit to help protect the driver. A 3.6-litre flat-6, from a
Porsche 911 GT3, was used in place of the standard 911 GT1 unit. However, Champion would instead turn to buy a
Lola B2K/10, so the Gunnar G-99 was temporarily abandoned. The car would resurface in the
Rolex Sports Car Series in 2002, yet would not be allowed to race until it had a roof again. Therefore, Gunnar Racing rebuilt the car with a near-identical GT1 roof, and briefly competed in 2003. The car would take a best finish of second in class twice before being retired due to lack of funding and due to the ban on SRP cars in favour of
Daytona Prototypes. == Street-legal version ==