Porsche 911 GT3

Porsche 911 GT3
Overview
Manufacturer	Porsche
Production	1999–present
Assembly	Stuttgart-Zuffenhausen, Germany
Body and chassis
Class	Sports car (S)
Body style	2-door coupé
Layout	RR layout
Powertrain
Engine	Flat-six engine
Transmission	6-speed manual or 7-speed dual-clutch gearbox

The Porsche 911 GT3 is a high performance version of the Porsche 911 sports car primarily intended for racing. It is a line of high-performance models, which began with the 1973 911 Carrera RS. The GT3, introduced in 1999, is named after the Fédération Internationale de l'Automobile (FIA) Group GT3 class, created in 2005, in which it was designed to compete.

A number of variations, designed for road and track duty, have been introduced since its launch in 1999. More than 14,000 911 GT3 cars have been produced.

The GT3 has had a successful racing career in the one-make national Porsche Carrera Cup series, and the international Porsche Supercup. It has won championship and endurance races, including the GT class of the American Le Mans Series seven times, first overall in the 24 Hours of Daytona, and first overall at the 24 Hours Nürburgring six times.

Road cars

996 GT3

996 GT3
Overview
Production	1999–2005
Powertrain
Engine	3.6L 360 PS (265 kW) H6, 3.6 L 380 PS (279 kW) H6
Dimensions
Length	174.6 in (4,435 mm)
Width	69.7 in (1,770 mm)
Height	50.2 in (1,275 mm)

996.1 GT3

The "GT3" nameplate was introduced in 1999 as part of the first generation of the Porsche 996 model range (commonly known as 996.1^[1]). As with Porsche's previous 911 RS models, the 996 GT3 was focused on racing, and so was devoid of items that added unnecessary weight to the car. Sound deadening was almost completely removed, as were the rear seats, rear loud speakers, sunroof, and air conditioning, although automatic air conditioning and CD/radio became no-cost optional add-ons.

The engine of the 996 GT3 set it apart from most of the other Porsche 996 models, although it shared the same basic design of the standard so-called "integrated dry sump" flat-six engine. The engine is naturally aspirated and based on the unit used in the Porsche 962 and Porsche 911 GT1 race cars. That engine was known as the 'Mezger' engine, after its designer Hans Mezger. The engine uses the original air-cooled 911's versatile dry-sump crankcase, with an external oil reservoir. The 996 GT3 has 360 PS (265 kW; 355 hp), compared to the 300 PS (221 kW; 296 hp) of the regular Porsche 996. In GT3 configuration, this so-called "split" crankcase (meaning the parting line of crankcase is on the crankshaft centreline) uses, instead of a fan and finned cylinders, separate water jackets added onto each side of the crankcase to cool banks of three cylinders with water pumped through a radiator. Thus, the GT3 engine is very similar to the completely water-cooled Porsche 962 racing car's engine, which is based on the same crankcase. The 962 differs, however, by using six individual cylinder heads while the GT1/GT3, like the air and water-cooled Porsche 959, uses two cylinder heads, each covering a bank of three cylinders. The GT3 engine could thus also be thought of as similar to a 959 engine, but with water-cooled cylinders. Up to early model year 2004 996 GT3 production, the basic casting used for the crankcase of the GT3 was the same as the air-cooled engine. The "964" casting number was visible on the bottom of the crankcase, and on areas normally machined in air-cooled applications, but not in water-cooled ones. The crankcase casting was changed in mid-2004 to a "996" casting number crankcase to eliminate these external air-cooled remnants, but internally it was the same.

Because the 911 air-cooled crankcase uses the Porsche 356 engine to transmission mounting flange configuration, the 996 GT3 used a manual gearbox also of air-cooled 911 heritage. This gearbox has interchangeable gear ratios and is more durable making it more suitable for racing than the standard 911 type 996 gearbox.

To bring the vehicle's track-prowess to the maximum level, Porsche endowed the GT3 with enlarged brakes, a lowered, re-tuned suspension system, lighter-weight wheels and a new front bumper with matched rear spoiler to help increase downforce, thereby increasing grip.

Porsche offered a no-cost option for the GT3 called the 'Clubsport' package. This option replaced the standard electrically adjustable leather front seats with manually adjustable racing buckets finished in fire-retardant fabric, single mass flywheel, bolt-in half-roll cage, 6-point drivers racing harness (also replacing the standard side airbags), fire extinguisher (mounted in the front passenger footwell) and preparation for a battery master switch. The Clubsport option was never offered to US customers, ostensibly due to the additional DOT crash testing that would have been required to allow US sales.

996.2 GT3

Porsche made significant updates to the GT3 for 2004 (the first year the car was offered to US customers), using the 2002 996 facelift including headlights that were differentiated from the Porsche Boxster. The 2004 version is commonly known as the 996.2 GT3.^[2] Horsepower was raised to 381 PS (280 kW) and torque to 284 lb·ft (385 N·m), 80% of which was available from 2,000 rpm. The braking setup was upgraded, now featuring 6-piston calipers on the front (rears remained 4-piston), and the Porsche Ceramic Composite Brake system was offered as an option.

In track testing by American automotive journals, the GT3 managed a 0-60 mph (97 km/h) time of 4.5 seconds and a quarter mile time of 12.0 seconds at 118 miles per hour (190 km/h). During skidpad testing the vehicle posted 1.03g.

Porsche's official test-driver Walter Röhrl completed the Nürburgring Nordschleife with the 996 GT3 in 7 minutes 56 seconds, a feat which was used by Porsche to promote the car.

• 
  1999 Porsche 996 GT3 (pre-facelift) front.
• 
  1999 Porsche 996 GT3 (pre-facelift) rear.
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  Porsche 996 GT3 (post-facelift) front.
• 
  2005 Porsche 996 GT3 (post-facelift) rear.

996 GT3 RS

In 2003, Porsche introduced the Porsche 911 GT3 RS, an even more track-focused version of the 996 GT3. RS is short for the German RennSport, literally "racing sport" in English. The "RS" moniker, and the characteristic lightweight blue or red wheels and "GT3 RS" side stickers link the 996 GT3 RS to historically important Porsches such as the Carrera 2.7 RS of the early 1970s. The 996 GT3 RS is lighter than the 996 GT3 thanks to a polycarbonate rear window, carbon fiber hood and rear wing. Porsche Ceramic Composite Brake (PCCB) Carbon fibre-reinforced Silicon Carbide (C/SiC) ceramic composite brakes, which are also more heat and fade resistant than the cast iron units fitted as standard, are optional.

The 996 GT3 RS has a slightly different engine specification to the 996 GT3. The cylinder heads of the 996 GT3 RS have reshaped intake and exhaust ports for race homologation. Porsche claim the same 381 hp (284 kW) power output as the standard GT3 but Porsche's control dyno showed a jump to nearly 400 hp (298 kW) The RS also has progressive springs rather than linear. The dampers are uprated and are between 10 and 15 percent stiffer than the 996 GT3 in bounce and rebound.

The wheel carriers are totally redesigned to maximize the improved dynamic camber control. The suspension top mounts can be turned 120 degrees to a cup car position. Both front and rear control arms are adjustable. The RS is 3 mm (0.1 in) lower than the 996 GT3.

The RS rear wing delivers 35 kg (77 lb) of downforce at 125 mph (201 km/h). The RS has ram air ducts on the engine bay which force air into the intake with 18mb of pressure at 187 mph (301 km/h) and this is enough to create an additional 15 bhp (11 kW; 15 PS). That extra bhp cannot be homologated since the official engine output figures are certified on a dynanometer.

The Porsche 996 GT3 RS had a production run from 2003 to 2005. Only 140 right hand drive 996 GT3 RS cars were built by Porsche and 113 of those were officially imported into to the UK. The 996 GT3 RS was not sold in USA or Canada.

Automobile magazines claim the 996 GT3 RS can accelerate from 0-60 mph (97 km/h) in about 4.3 seconds, maintain over 1.0g on the skidpad, and have a top speed of around 190 mph (306 km/h).

• 
  Porsche 996 GT3 RS front.
• 
  Porsche 996 GT3 RS rear.

997 GT3

997 GT3
Overview
Production	2006–2011
Powertrain
Engine	3.6 L 415 PS (305 kW) H6 3.8 L 435 PS (320 kW) H6 3.8 L 450 PS (331 kW) H6 4.0 L 500 PS (368 kW) H6
Dimensions
Length	174.3 in (4,427 mm)
Width	71.2 in (1,808 mm)
Height	50.4 in (1,280 mm)

997.1 GT3

In February 2006, Porsche revealed the first generation 997 GT3, commonly now known as the 997.1 GT3.^[3] In addition to a new 415 PS (305 kW) 3.6 litre flat-six engine, the vehicle featured "zero lift" aerodynamics, meaning the car creates only aerodynamic downforce and no grip-diminishing "lift" upwards and away from the road surface. The vehicle made use of a modified, track oriented version of Porsche's active PASM suspension making it the first of Porsche's RS or GT3 versions to feature an electronically adjustable suspension system. Also available was a navigation system and Porsche's "sports chrono" gauge package. The car went to sale in summer of 2006 and had a starting price of $106,000 USD. A total of 917 units were sold in the United States and 46 units in Canada.

The vehicle has a rated 0-60 mph (97 km/h) time of 4.1 seconds and has a top speed of 193 mph (311 km/h). Road and Track was able to achieve a 0-60 mph run in 3.8 seconds.^[4] Porsche's official test-driver Walter Röhrl completed the Nürburgring Nordschleife in 7 minutes 42 seconds with the 997 GT3 in 2006.

997.2 GT3

In 2009, Porsche launched the 2nd Generation 997 GT3 (commonly now known as the 997.2 GT3^[5]), with an enlarged 3.8 litre engine producing 435 PS (320 kW). It also featured a number of new options including dynamic engine mounts and a pneumatically lifting front axle to compensate for the low ground clearance. The rear spoiler was also modified along with other parts of the bodywork. Deliveries in Europe commenced in November the same year. A total of 65 units were sold in the United States and 58 units in Canada.

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  2006 Porsche 997 GT3 (pre-facelift) front.
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  2006 Porsche 997 GT3 (pre-facelift) rear.
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  Porsche 997 GT3 3.8 (post-facelift) front.
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  Porsche 997 GT3 (post-facelift) 3.8 rear

997 GT3 RS

Porsche also offered an RS version of the 997 GT3. In common with its predecessors, it provided a homologation model for use in a range of racing series. The 997 GT3 RS was released in Europe in October 2006 and in North America in spring 2007.

The 997 GT3 RS is 20 kg (44 lb) lighter than the 997 GT3, weighing in at 1,590 kg (3,505 lb). This weight-saving was achieved by the use of an adjustable carbon plastic wing, a steel engine cover, and a lightweight plastic windscreen. The weight savings gives the 997 GT3 RS corresponding engine power to curb weight ratio of 300 bhp (220 kW) per tonne.

The body of the 997 GT3 RS is 64 mm (2.5 in) wider at the rear than the 997 GT3 (a legacy from the Carrera 4 models with which it shares its shell). The muscular-looking rear end conceals a wider track that not only improves directional stability but also increases the potential cornering grip. However, drag is increased and top speed reduced. In addition to the new technology, the paint scheme and body panels are all designed specifically for this car. For the RS version, the limited edition RS Green and RS Orange colour was mixed specially for this car.

The American version of the 997 GT3 RS has a standard rear window (not plexiglas) and the smaller 911 fuel tank to comply with rules of SCCA, Can-Am, and IMSA. For Grand-Am races, the central locking wheel nut is replaced with the standard five-lug pattern required under Grand-Am rules.

Production of the first generation 997 GT3 RS (997.1 GT3 RS^[6]) ended in 2009. An estimated 1,168 vehicles were delivered worldwide, with a total of 410 units sold in the United States and 42 units in Canada.^[7]

For 2010, the second generation 911 GT3 RS (known as 997.2 GT3 RS^[8]) received an additional 15 PS (11 kW; 15 hp) due to a new 3.8-liter flat-six, bringing total power output up to 450 hp (336 kW; 450 hp). This car was not approved for competition in the United States by IMSA American LeMans. Grand-Am originally did not approve the car, but after performance issues (a Porsche team did not compete at the Indy Grand Prix of Alabama round), Grand-Am approved the second-generation car in April 2010.^[9][10]

Fifth Gear carried out a road test on the 997 911 GT3 RS which highlighted the exceptional performance of the car^[11]

Porsche test driver had intended^[12] to enter the 2011 12 Hours of Nürburgring on a standard road legal 911 GT3 RS, but had to withdraw due to health reasons from the team that comprised racers Roland Asch and Simon Cowell, plus journalists Horst von Saurma and Chris Harris. The car, entered in cooperation with sport auto (Germany),^[13] is registered as S-GO 2400, and was driven from Weissach to Nürburg. The RS was modified according to safety requirements, which included a larger roll cage and fire extinguisher. As no race tyres were available for 19" rims, the 18" wheels of the Cup racers were used. Asch qualified with 9:15, 42nd overall, and 9th^[14] among the 17 SP7 class entrants, only beaten by its race-prepared Porsche 997 siblings. In an otherwise disappointing race for Porsche, with the best race 997 finishing only 6th, the road legal car did 145 laps, only 9 less than the winning BMW, for place 13.^[15] It supposedly had to cover another 306 km, on the Autobahn back home.

Of the 997.2 GT3 RS a total of 541 units sold in the United States and 71 units in Canada

• 
  Porsche 997 GT3 RS (pre-facelift) front.
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  Porsche 997 GT3 RS (pre-facelift) rear.
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  Porsche 997 GT3 RS (post-facelift) front.
• 
  2010 Porsche 997 GT3 RS (post-facelift) rear.

997 GT3 RS 4.0

The 911 GT3 RS 4.0, launched in 2011, was the final evolution of the 997 GT3 and featured a 4.0 litre flat-six engine (the largest engine offered in a street-legal 911).^[16] The engine itself uses the crankshaft from the RSR with increased stroke dimensions (from 76.4 mm to 80.4 mm). This change has increased the power to 368 kW (500 PS; 493 hp) at 8250 rpm and 460 N·m (339 lbf·ft) of torque at 5750 rpm. Chassis development has been influenced by the GT2 RS and uses parts from other RS 911s. Front dive planes give additional downforce up front. The car weighs in at 1,370 kilograms (3,020 lb), giving it a power-to-weight ratio of 365 bhp per ton. Only 600 cars were built.^[16][17] At 493 hp (368 kW),^[18] the engine is one of the most powerful six-cylinder naturally aspirated engines in any production car with a 123.25 hp (92 kW) per litre output.

Performance is 3.5 seconds for 0-60 miles per hour (97 km/h) and a top speed of 193 mph (311 km/h).^[19] The lap time on the Nürburgring Nordschleife is 7 minutes and 27 seconds.^[20]

The car was offered in Black, Carrera White, Paint to Sample Non Metallic and Paint to Sample Metallic. A total of 141 units were sold in the United States and 16 units in Canada.

• 
  2011 Porsche 997 GT3 RS 4.0 front.
• 
  Porsche 997 GT3 RS 4.0 rear.

991 GT3

911 GT3
Overview
Production	2013-present
Powertrain
Engine	3.8 L 475 PS (349 kW) H6 4.0 L 500 PS (368 kW) H6
Dimensions
Length	178.94 in (4,545 mm)
Width	72.91 in (1,852 mm)
Height	49.96 in (1,269 mm)

Porsche introduced the 991 GT3 at the Geneva Motor Show in 2013.^[21] The 991 GT3 features a new 3.8 litre direct fuel injection (DFI) flat-six engine developing 475 hp (354 kW; 482 PS) at 8,250 rpm, a Porsche Doppelkupplung (PDK) double-clutch gearbox and rear-wheel steering. The engine is based on the unit fitted in the 991 Carrera S, but shares only a few common parts. All other components, particularly the crankshaft and valve train, were specially adapted or developed for the 991 GT3.^[22] For example, the 991 GT3's engine uses titanium connecting rods attached to forged piston, in order to allow the engine to reach up to 9,000 rpm. The dual-clutch gearbox is another feature specially developed for the 991 GT3, based on sequential manual transmissions used in racing cars.^[23]

After a number of engine failures, it was discovered that the supplier of the connecting rod bolts had made a production error in the alloy of the bolt.^[24] Subsequently, all 785 of the GT3s that had been produced up to that point were recalled to the dealership organisations and fitted with new engines, and all owners were issued with an extra year's warranty.^[25]

A formal letter sent to Porsche from members of the US-based Rennlist.com "991.1 GT3 Concerned Owners Group" about additional engine durability issues lead to a meeting between representatives of the owners group and Porsche, including head of Porsche Motorsport Dr. Frank-Steffen Walliser, on 3 August 2017 at the Porsche North America Atlanta headquarters. According to Dr. Walliser the concerning high-RPM misfire issue could be traced primarily to a metallurgical defect in certain batches of "finger followers" (valve train rocker arms) and secondarily to individual driving patterns and engine variations - such as temperature, oil quality, oil viscosity and parts tolerances - that lead to increased wear of the specific parts. In response to the issue and after implementing new engine tests to trace down the issue Porsche had developed revised camshafts and finger followers and offers a fully transferable 10-year, 120,000 mile extended engine warranty to all 991.1 generation GT3 owners world-wide that covers the replacement of the defective engine with a new engine with the revised parts if failure is a direct result of the finger-follower issue. The base bumper-to-bumper warranty and all other warranty terms and conditions remain unchanged. Porsche confirms that the issue is isolated to the 991.1 GT3, and that the 991.1 GT3 RS and the 991 R are not affected.^{[26][27][28][29]}

The 911 GT3 is claimed to be able to accelerate from 0-60 mph (97 km/h) in 3.1 seconds or less, and the quarter mile in 11.2 seconds at 126 mph (203 km/h).^[30][31] The GT3 has a claimed top speed of 202 mph (325 km/h). The lap time on the Nürburgring Nordschleife is 7 minutes and 25 seconds.^[32]

991.1 GT3 RS

Porsche launched the RS version of the 911 GT3 at the Geneva Motor Show in 2015.^[33] Compared to the 911 GT3, the front fenders are now equipped with louvers above the wheels and the rear fenders now include Turbo-like intakes, rather than an intake below the rear wing. The roof is made from magnesium. The interior includes full bucket seats (based on the carbon seats of the 918 Spyder), carbon-fibre inserts, lightweight door handles and the Club Sport Package as standard (a bolted-on roll cage behind the front seats, preparation for a battery master switch, and a six-point safety harness for the driver and fire extinguisher with mounting bracket).The car was nominated as one of the Britain's best driver's car 2014 by Autocar magazine.

The 3.8-litre unit found in the 911 GT3 is replaced with a 4.0-litre unit with 500 horsepower and 339 pound-feet (460 N·m) of torque. The transmission is PDK only (with the exception of the rare 1 of 1 worldwide manual owned by Robert Janev and assembled by BGB Motosports). The drivetrain delivers 0-62 mph (0–100 km/h) in 3.4 seconds (0.6 seconds quicker than the 997 GT3 RS 4.0) and 0-124 mph (0–200 km/h) in 10.9 seconds. The 991 GT3 RS also comes with functions such as declutching by "paddle neutral" — comparable to pressing the clutch with a conventional manual gearbox –- and Pit Speed limiter button. As with the 911 GT3, there is rear-axle steering and Porsche Torque Vectoring Plus with fully variable rear axle differential lock. The Nürburgring Nordschleife time is 7 minutes and 20 seconds.^[34]

991.2 GT3

Porsche released its facelifted 991.2 GT3 at the 2017 Geneva Motor Show in 2017. Changes made from the 991 are the engine and the spoiler, which is 20% taller. The engine unit is a "Carbon Copy" of the 911RSR engine, producing 500 horsepower. Another change from the 991 is the introduction of a manual transmission option, along with the PDK version.

Specifications (road cars)

Car	Years of Production	Engine Displacement (cm³)	Power (PS)	Power (kW)	Power (hp)	Weight (lb)	Weight (kg)	Units Built[35]	0-62 mph (100 km/h)
996.1 GT3	1999-2001	3,600	360	265	355	2,976.2	1350	1,868
996.2 GT3	2003-2005	3,600	381	280	376	3,042.4	1380	2,313
996.2 GT3 RS	2003-2004	3,600	381	280	376	2,998.3	1360	682
997.1 GT3	2006-2009	3,600	415	305	409	3,075.4	1394	2,378[36]
997.1 GT3 RS	2006-2009	3,600	415	305	409	3,031.4	1375	1,106
997.2 GT3	2009-2011	3,797	435	320	429	3,075.4	1394	2,256[37]
997.2 GT3 RS	2009-2011	3,797	450	331	443	3,020.3	1370	Approx. 1,600
997.2 GT3 RS 4.0	2011	3,996	500	368	493	2,998.3	1360	600	3.5s
991.1 GT3	2013-2016	3,799	475	349	468	3,152.6	1430 (DIN)	3500	3.5s
991.1 GT3 RS	2016-2017	3,996	500	368	493	3,130.6	1420 (DIN)	6500	3.3s
991.2 GT3	2017-	3,996	500	368	493	3,152.6	DIN: 1430 (PDK), 1413 (manual)	In production	3.4s (PDK), 3.9s (manual)

Racing

Racing cars

The following race versions were or are offered:

• 1998 996 GT3 Cup
• 1999 996 GT3 R
• 2000 996 GT3 Cup^[38]
• 2001 996 GT3 RS
• 2004 996 GT3 RSR – with sequential gear box^[39]
• 2005 997 GT3 Cup^[40]
• 2006 997 GT3 RSR^[41]
• 2008 997 GT3 Cup S^[42]
• 2010 997 GT3 Cup^[43]
• 2010 997 GT3 R^[44] – homologation includes 2013 bodywork update^[45]
• 2012 997 GT3 RSR^[46]
• 2013 991 GT3 Cup^[47]
• 2013 991 RSR
• 2014 991 GT America
• 2016 991 GT3 R
• 2017 991 RSR^[48]
• 2017 991 GT3 Cup^[49]

Apart from numerous class wins, the GT3 won major events overall:

• 24 Hours Nürburgring in 2000, 2006, 2007, 2008, 2009, 2011
• Spa 24 Hours in 2003, 2010
• 24 Hours of Daytona in 2003
• Petit Le Mans in 2015

Also, at the Nürburgring, the GT3 RS and modified versions (with 3.9 litre engine) win many VLN races.

The various national Porsche Carrera Cup series, and the international Porsche Supercup which is mainly run at Formula One events, also use the GT3 Cup.

997 GT3 Cup 3.8 (2009–2011)

The 997 is a Porsche Carrera Cup race car based on 911 GT3 RS. It includes 44 mm (1.7 in) wider rear body, 15 mm (0.59 in) lower front spoiler lip, 1.70 m (67 in) rear wing (from 911 GT3 Cup S race car), LED taillights, racing exhaust system with a fully controlled catalytic converter, a modified special exhaust system offering more dynamic and muscular sound (from Porsche Mobil1 Supercup cars), Porsche Ceramic Composite Brakes. 9.5Jx18 front alloy wheels with 24/64-18 Michelin racing tyres and 12Jx18 alloy wheels with 27/68-18 tyres, additional Unibal joints on the track control arms and front and rear sword-shaped anti-roll bars with seven position settings each, additional vent in the upper part of the front lid, steering wheel mounted Info Display with 6 switches, Carrara White body. The vehicle was unveiled in 2009 Frankfurt Motor Show.

Production model began delivery in 2009–10. European model has base MSRP of €149,850 (before tax).^[50]

997 GT3 R Hybrid

The new Porsche 997 GT3 R Hybrid made its debut at the 2010 Geneva Motor Show. The hybrid technology featured in the car was developed by the Williams F1 Team and is based on their F1 kinetic energy recovery system (KERS) which they did not race in 2009.^[51] Unlike other KERS that were developed for F1, the Williams system is based on using kinetic energy stored in a flywheel rather than batteries. The GT3-R has two electric motors, both developing a total output of at least 218 brake horsepower (163 kW), driving the front wheels to supplement the 500 brake horsepower (370 kW) four-litre flat-six engine at the rear.^[52] It is planned to enter the car in the 2010 24 Hours Nürburgring.^[53][54] As part of the buildup to the 24 hour race the GT3 Hybrid made its racing debut at the VLN 4 hour endurance 57th ADAC Westfalenfahrt at Nürburgring on March 27, 2010.^[55] On May 28, 2011, it won its first VLN race.^[56] At the 2011 24 Hours of Nurburgring, weight/restrictor penalties as well as technical difficulties prevented the R Hybrid from climbing higher than 28th place. The car also ran as an unclassified car at the 2011 American Le Mans Series at Monterey event; despite starting from last place, it finished ahead of all the other GT cars and also performed the fastest GT lap of the race.

997 GT3 RSR (2006–2012)

The Porsche 997 GT3 RSR was developed for the GT2 category and has a dry weight of 1,220 kg (2,690 lb) and 563 bhp (420 kW; 571 PS).^[57] In 2007 Porsche had also installed front air louvers that channel air into the radiators and exit through the bonnet. For 2011 Porsche added splitters to the front and increased the tyre diameter to cope with the understeer problem. The 997 GT3 RSR has scored many class victories around the world, including first-place finishes at the 2011 and 2013 Petit Le Mans. The 997 GT3 RSR set a Nürburgring Nordschleife lap time record for non-turbocharged cars at 7:07 while driven by Sabine Schmitz.^[58]

991 GT3 Cup

Porsche introduced the 991 GT3 Cup for the 2013 Porsche Supercup season, based on the 991 GT3. Like the 991 GT3 road car, its improvements over the 997 model include revised aerodynamics, an improved rollcage, new wheels and a revised chassis. The direct-injection 3.8-litre flat six produces 338 kW at 8500 rpm and drives the rear wheels through a mechanical limited slip diff. The transmission includes a paddle-shift, race-bred, pneumatically-activated six speed developed specifically for the track. It uses lightweight materials in its construction, and a stripped-out cabin complete with a full roll cage, racing seat and all the safety gear required for competition, weighing 1175 kg.^[59]

991 RSR (2013–2016)

In 2013, Porsche introduced the newest version of the RSR based on the 991 model for the LM GTE category.^[60] Because the 991 GT3 was not in production at the time of the announcement, Porsche was forced to homologate it based on the 911 Carrera model. The 991 RSR includes revised aerodynamics, a lighter gearbox and a new, lower suspension.^[61] For the 2013 season, Porsche retained the Metzger engine of the 997 GT3 RSR model. Manthey Racing was chosen to run the cars in the FIA World Endurance Championship; the team achieved its best success at the 2013 24 Hours of Le Mans where the 991 RSR finished 1-2 in the GT class.^[62]

For 2014, Porsche announced that it partnered with CORE Autosport to run 2 Porsche 911 RSRs in the United SportsCar Championship (under the Porsche North America team name) while AKB GT Raceline has announced that they would run a pair of 911 RSRs in the series. Team Falken Tire also announced that it would be running a 911 RSR from Sebring onwards. Manthey Racing will continue to run two 911 RSRs in the WEC.

991 GT America

Porsche also announced a variant of the 991 GT3 Cup car for the United SportsCar Championship known as the 911 GT America.^[63] The car is homologated exclusively for the Grand-Touring Daytona category of the series. Upgrades over the regular Cup car include improved aerodynamics, a bigger 4.0L flat-six engine, a new gearbox, a different safety cell, new brakes and reliability upgrades for endurance racing.

991 GT3 R

In May 2015, Porsche announced the release of the 991 GT3 R, a customer race car designed to compete in Group GT3 from 2016 onwards. The car is homologated based on the 991 GT3 RS road car, and uses the production car's 4.0-litre flat-six with around 500 bhp, running through a six-speed paddle-shift sequential gearbox. The GT3 R features a double-bubble roof, and a wheelbase which had been lengthened by 8.3 cm. Engineers also "significantly optimised" the centre of gravity position versus the old R, using carbon-fibre composite material (CFRP) for the roof, front cover and fairing, wheel arches, doors, side and tail sections as well as the rear cover. All windows – and for the first time ever, the windscreen – are made from polycarbonate to cut weight. Race car essentials such as an integrated (welded) roll cage according to FIA Appendix J, safety fuel cell (approximately 120 litres, with fuel cut off safety valve in accordance with FIA regulations), removable roof escape hatch and an air jack system are present. The weight is 1,220 kg.

The GT3 R has adopted the concept of the central radiator from its 911 RSR big brother. By eliminating the side radiators, the position of the centre of gravity is improved, the radiator is better protected against collision damage, and the venting of hot air through louvres in the front cover is enhanced. The two-metre wide rear wing lends aerodynamic balance and distinctive wheel arch air vents on the front fairings increase downforce at the front axle. The GT3 R's front McPherson strut suspension and multi-link rear suspension are adjustable in height, camber and toe, and there are adjustable anti-roll bar blades at both ends. All wheel hubs come with centre-lock wheel nuts. There are two separate brake circuits for the front and rear axles; driver adjustable via a brake balance bar system. The front brakes consist of six-piston aluminium monobloc calipers gripping 380 mm discs; the rears are four-piston items with 372 mm discs.^[64]

The Porsche 911 GT3 R is priced 429,000 euros excluding country-specific taxes.

991 RSR (2017–)

In November 2016, Porsche revealed the new version of the 911 RSR prepared for the LM GTE category. The car has a mid-engined design, powered by a four-liter flat-six boxer engine placed in front of the rear axle. It is estimated to produce 510 horsepower. Other new features include a new transmission, a new aerodynamic pack, a larger rear diffuser and new suspensions. The car made its debut at the 2017 24 Hours of Daytona.^[65]

Racing history

1999

Due to the absence of the official Porsche team in the 1999 24 Hours of Le Mans, only privateers with the nearly obsolete air-cooled 993 GT2 Turbo were expected to represent the marque, with few chances to beat the Chrysler Viper for GTS class honors. Two new race versions of the water-cooled 996 GT3-R were entered in the GT class by private teams. The car entered by the German Manthey Racing team finished 13th overall.

2000s

The 996 GT3-R were made available to privateer teams. In the 24 Hours Nürburgring of the year 2000, a factory-backed effort of the local Phoenix team managed to beat the Zakspeed Chrysler Viper that dominated this race from 1998 to 2000. The improved 996 GT3-RS version of 2001 was entered in countless races in the years to follow, scoring not only many class wins, but also overall wins at Daytona and Spa in 2003. In 2004, the 996 GT3-RSR was made available, with numerous improvements to the RS, including a sequential gearbox, which allows for faster gearshifts.

VLN

In 2005, the new 997-generation racing vehicles began to debut with the GT3 Cup, followed by the launch of the 911 GT3-RSR at the 2006 Spa 24 Hours. In VLN endurance races, the Manthey entry won the last 4h race before the 24h event, and then the big event also. Their Porsche 997 GT3 RSR has a larger front splitter, taller rear wing and a 500 bhp 4.0L Flat-6 engine.

24 Hours of Le Mans

After winning the 1998 24 Hours of Le Mans outright, Porsche dominated the GT/N-GT class at Le Mans. There were no major competitors and Porsche took seven consecutive class wins from 1999 to 2005. In 2006 the Porsches led for much of the race but one by one the competitors hit bowel problems and withdrew. Last minute mechanical issues threw the Seikel car back behind the surprising winner Panoz Esperante.

2007 saw the debut of the 997 GT3 RSR. IMSA Matmut took pole by more than a second over the Ferrari (but lost it after breaching Parc Fermé rules). The new Porsche was now fitted with wider rear tyres and smaller restrictors than the rules allow. This was compensated by the car weighing 100 kg more. The Porsche now stood at 1220 kg and 485 bhp. This was an advantage at Le Mans over the lighter and nimbler F430.

Le Mans Series

Felbermayr-Proton and IMSA-Matmut received the new 997 just before the 2007 season. Marc Lieb and Richard Lietz share the better of the two Felbermayr cars. Patrick Pilet and Raymond Narac share the IMSA car. Felbermayr-Proton won the championship in 2009 and 2010. In 2011, Nicholas Armindo won the GTE-Am class.

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  2003 Porsche 996 GT3 RS rear.
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  2005 Porsche 996 GT3 RS front.
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  2006 Porsche 996 GT3 Cup front.
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  Porsche 996 GT3 Cup rear.
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  Porsche 996 GT3 RSR front.
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  Porsche 996 GT3 RSR rear.
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  Porsche 996 GT3 RS GT300 front.
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  2007 Porsche 997 GT3 RSR front.
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  2010 Porsche 911 GT3 R Hybrid front.
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  2011 Porsche 997 GT3 R front.
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  2011 Porsche 997 GT3 RSR front.
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  2013 Porsche 997 GT3 Cup front.
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  2008 Porsche 997 GT3 Cup rear.
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  2014 Porsche 991 GT3 Cup front.

See also

• 9ff GT9, a high-speed automobile, based on the 997 GT3
• Ruf RGT, a sports car similar to the GT3 built by Ruf Automobile

References

External links