In 1993, Porsche developed a highly tuned 964 Turbo S prototype for use in international motorsport. The car, known as the Turbo S Le Mans GT (or simply Turbo S LM-GT), was based on the standard road-legal Turbo S, but stripped down and modified for circuit use. A deep chin spoiler was added to the front, while two air inlets were added just above the rear wheel fenders. An adjustable racing rear wing was added on top of the standard Turbo's wing. Wider fenders were used to house 12-inch (300 mm) wide racing slicks. The interior was completely stripped, a rollcage added, and the windows replaced with plastic. The engine used was not the standard road-car unit, but a smaller twin-turbocharged 3.2 liter unit which produced 475 hp.
The Turbo S LM-GT made its debut at the 1993 12 Hours of Sebring where the car finished seventh overall and first in its class with the Brumos Porsche racing team. From there, the car was entered in the 24 Hours of Le Mans, running under the guise of the Porsche factory team. The car would however fail to finish after the engine was damaged early in the race. For 1994, the Turbo S LM-GT would be moved to the hands of Larbre Compétition, where a new 3.6 liter engine based on the 993 unit would be used in place of the 3.2 liter engine. The team opened the year with a second place finish at the 24 Hours of Daytona, before moving on to select rounds of the BPR Global GT Series. The car would win all four races in which it competed, including the 1000 km Suzuka. The Turbo S LM-GT would make a few select appearances in 1995 with Obermaier Racing before being retired.
The development work from the Turbo S LM-GT helped Porsche in creating the 993-generation 911 GT2 in 1995, which would be mass produced and sold to racing customers. Some teams, unable to buy new 911 GT2s, developed their own twin-turbo racing versions of the 964 Turbo to mimic the Turbo S LM-GT, but lacked the success of the factory project.
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