Porsche introduced the 996 GT3 R from mid-1999, built on the 3.6-litre naturally aspirated flat-six in racing trim producing 415 horsepower at 8,200 rpm and 380 Nm at 7,000 rpm. Sixty-six units were produced. The car made its competitive debut at the 1999 24 Hours of Le Mans and immediately took a class victory. In the 2000 FIA GT Championship it won every round in the N-GT class, and factory-supported Phoenix Racing won the Nürburgring 24 Hours that same year.
In 2001 the revised GT3 RS appeared, with improved aerodynamics and approximately 51 units produced. It was still more dominant than the GT3 R, also achieving outright victories in certain events. At the 2003 Daytona 24 Hours, Bergmeister and Bernhard won the race outright in the GT3 RS. The successor the RSR was built to continue the line of five consecutive Le Mans class victories accumulated by the R and RS together.
The GT3 RSR, produced for the 2004 and 2005 seasons, was built in 27 units according to one source and 37 according to another. The 3.6-litre water-cooled flat-six produces 445 horsepower at 8,250 rpm in the primary specification, with maximum torque of 405 Nm at 7,200 rpm. The radical-mag source cites 455 horsepower at 8,500 rpm for what it describes as the production figure. The FIA specification uses two 30.8 mm air restrictors.
A six-speed sequential gearbox with ignition cut for clean full-throttle upshifts replaced the earlier manual unit, providing quicker and more reliable gearchanges under endurance race conditions. The racing suspension uses McPherson struts at the front and Porsche's multi-link axle at the rear, with revised wheel-uprights and modified mounting points compared to the GT3 RS. Double springs adjustable to four settings, adjustable dampers, adjustable anti-roll bars, and uniball joints allow precise circuit-specific setup.
The brake system uses four-piston aluminium callipers on all four wheels, with 380 mm discs at the front and 355 mm at the rear. In FIA specification the car weighs 1,100 kg; ACO specification for Le Mans and American Le Mans Series events brings minimum weight to 1,115 kg. Both weights represent the minimum limit for their respective regulations. The front bodywork was redesigned to improve downforce at the front axle and includes a characteristic air inlet generating ram pressure.
By 2006, the combined 996 GT3 R, RS, and RSR programme had achieved seven class wins at the 24 Hours of Le Mans and five class wins plus one outright victory at the Spa 24 Hours. The RSR was available to customers in either ACO or FIA specification, allowing a single purchase to be configured for Le Mans, the American Le Mans Series, or FIA GT Championship events depending on the team's programme. Porsche Motorsport delivered the first RSR units in December 2003 ahead of the 2004 season.
The car's successor, the 997-generation GT3 RSR, carried forward the same customer racing philosophy into the second half of the 2000s, but the 996 RSR remained in customer hands and in competition well beyond its official production period.