Nissan NPT-90

The Nissan NPT-90 was a racing car developed in 1990 for Nissan Motors by Nissan Performance Technology Incorporated (NPTI), formerly known as Electramotive Engineering. It was a replacement for the highly successful GTP ZX-Turbo that had won the IMSA GT Championship in 1989. The NPT-90 would go on to win the championship in 1990 and 1991 before being retired by Nissan at the end of the 1992 season.

Although officially known as the NPT-90, the car continued to race with the GTP ZX-Turbo naming painted on it. This was an attempt by Nissan to continue to use that name to market for the Nissan 300ZX road car.

Following five years of development and improvement on the GTP ZX-Turbo, Nissan realized that incoming competition from Toyota and Jaguar meant that a new car was needed to be able to continue to defend their championship. NPTI, Nissan's North American motorsports division, was therefore tasked with construction of an all-new car, abandoning the original Lola-based GTP ZX-Turbo chassis. The new car would abandon the angular look of the previous car, with the cockpit being rounded and narrower. The large intakes at the nose of the car would also be replaced with smaller duct work, while large vertical snorkels for the turbocharger would be placed on the sides of the car.

Nissan chose to continue to use the VG30 3.0 litre turbocharged V6 engine that had previously powered the GTP ZX-Turbo, but with improvements to allow for more power output, including the addition of a four-valve head to replace the two-valve design. Eventually, in 1992 Nissan chose to reduce the VG30s displacement to 2.5L in the NPT-91.

The NPT-90 would be upgraded during its life, leading to the cars being renamed NPT-91 in the middle of the 1991 season. Further upgrades during 1992 would come in various specifications, signified as NPT-91A through NPT-91D.

While the first NPT-90 chassis were under construction, NPTI began the 1990 season using the older GTP ZX-Turbos. The first chassis would be completed halfway through the season and debut at Topeka where it took an eighth-place finish, behind the second place GTP ZX-Turbo. Although engine problems at Lime Rock Park would put the lone NPT-90 out of the race, it would quickly show its potential at the next round at Mid-Ohio by taking the race win. With a second victory at Watkins Glen, and the second chassis completed, the NPT-90s would completely take over from the GTP ZX-Turbos.

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Wikipedia