Model history: Run out of El Segundo, California by Don Devendorf's Electramotive, Nissan's GTP program was by far the most successful sports car effort of the Japanese manufacturer during the late 1980s. The cars used consisted of a chassis built to specification by Lola, a Nissan supplied V6 engine and a body developed in-house. Following back-to-back IMSA Championship wins in 1988 and 1989, Nissan bought out Electramotive and retitled the company 'Nissan Performance Technology Inc.' or 'NPTI' from 1990. The first fruit of this reorganisation was an all-new car introduced halfway through the year.
The design team was led by Yoshi Suzuka, who for the first time could create an aerodynamics package without having to work around an existing chassis. This was vital as the GTP cars relied heavily on ground-effect aero for their performance. Accordingly, Suzuka's design featured massive tunnels that ran on either side of the cockpit and exited behind the rear suspension. Additional downforce at the front was generated by small diffusers mounted ahead of the front wheels. The rear end featured a full-width rear wing, which served predominantly for trimming the balance.
Trevor Harris then filled the space left by Suzuka with a bespoke chassis. This was constructed from a honeycomb structure sandwiched by aluminium sheets. In choosing the gauge of the material used, Travis had to consider both maintaining the high level of rigidity required to make the ground-effect aerodynamics work, while also keeping the weight down to a minimum. To clean up the airflow into the tunnel, the front springs were mounted high in the monocoque and were actuated by rockers. Other than the location of the springs, the double wishbone suspension was conventional on both ends.
The NPT-90 was fitted with a further development of the twin turbo V6 previously used. It initially displaced just under three litre and featured a single overhead camshaft. The engine was an area of constant development with four-valve heads quickly being readied. A smaller displacement version was also constructed, which allowed the car to run at a lower minimum weight. In its original guise, the NPT-90 featured turbo inlets in the flanks just behind the door, while later versions sported prominent snorkels. The intercoolers were fed from intakes in the nose with the ducts running through the chassis.
Entered alongside the existing GTP ZX-T, the first NPT-90 made its debut at the May 5th Topeka round of the IMSA GTP Championship. Within a month after making its first appearance and in only its third race, the new Nissan racer was driven to victory by reigning champion Geoff Brabham and Derek Daly. Faced with ever growing competition from the All American Racers built Toyota-Eagles, the NPT-90 was driven to two more victories before the season was out. Helped by the wins scored by the GTP ZX-T earlier in the year, Nissan and Brabham managed to successfully defend their championship.
Nissan's added involvement was not all good news for the GTP effort as first Suzuka was called back to Japan to help with the development of the under-performing Group C car and later NPTI was tasked to run two of these Group C cars at the 24 Hours of Le Mans in the Summer of 1990. As a result of these personnel changes and added distractions, development of the NPT-90 was very limited. Renaming the car NPT-91 for the new season, did little to cover this up. All American Racers on the other handed readied a brand new Toyota-engined Eagle, which fortunately did not debut until late in 1991.
In its 1991 guise, the NPT-90 only managed to win two races, which did include the important Sebring 12 Hours. A very consistent season from Geoff Brabham did enable him to score his fourth championship win in a row. The team soldiered on in 1992 with only another minimal evolution. By this time the car created so much downforce that at Road Atlanta the load literally destroyed the tyres. Brabham and NPTI won just a single race in a season that was utterly dominated by the All American Racers. Nissan's stronghold on the IMSA GTP Championship had finally lifted after four seasons.
Meanwhile, orders from Japan prompted the development of an all new car that was built to the new 3.5 litre Group C regulations. Although at least four cars were built, this new NP35 was raced only once and at the start of 1993 the project was abandoned. NPTI folded soon after with Nissan's honour being upheld by privateers like Gianpiero Moretti. As the last of a great line, the NPT-90 extended Nissan's success in the IMSA GTP Championship but it could not quite dominate the series like its predecessors had done.
Chassis: 90-10
Originally built as chassis 90-02, this Nissan NPT-90 was raced extensively by the NPTI team during the 1990 and 1991 seasons. In 1992, it served mainly as a spare car but when pressed into service, it was involved in one of the massive shunts at Road Atlanta. The remains were acquired by Matrix Motors, who rebuilt the car with spare chassis 90-10 to its original specifications. In 1993 the car was one of two NPT-90s used by the late Gianpiero Moretti with the legendary Derek Bell as his co-driver. Together with John Paul Jr., the experience pairing finished second in that year's Sebring 12 Hours.
Following its contemporary racing career the car passed through the hands of Pete Racely and Peter Stoneberg before it was sold to a British enthusiast. He campaigned the car for several years in the Historic Group C Championship. Today the car is fitted with a twin-cam, 2.7 litre engine, which is good for a reliable 670 bhp in race trim. The current owner acquired the car in 2012 and has since raced the Phil Stott Motorsport prepared Nissan at various events including the Group C support race of the 24 Hours of Le Mans.
Article by Wouter Melissen, last updated on October 04, 2012
The NPT-90 was the result of a very good racing outfit backed up by the full resources of Nissan. Nissan spent nearly $40 million per year in those days on the GTP program and the result was that they were all but untouchable. The NPT-90 looked great in the red, white and blue livery and it was devastatingly fast at the same time. The V6 turbo would give at least 750bhp during races and was rumoured to be good for 1100bhp without restrictors. However the aerodynamics were the real forte, with up to 9300 lbs of downforce at 200mph. With more than twice as much downforce as a modern sports prototype, it's no wonder it's one of the quickest closed wheel racers ever built. It was also one of the last ground-effects racing cars before spoil-sport rule changes took effect.