|T810 - Nissan GTP ZX-T|
Electramotive became America's leading specialists in the sale and preparation
of road and racing Nissans, and when the Japanese company decided to
enter the GTP category, they naturally approached Devendorf to run the
project. First of all, Devendorf bought a Lola T810 rolling chassis
which was really a T710 monocoque, very similar to the tubs built for
GM for their "Corvette GTP" project. The T810 had slight detail
modifications to allow for the Nissan engine, cooling and bodywork installations.
The two chassis shared the same suspension installation and physical
The John Knepp-developed turbo V6 engines, based upon the production "Z" car engine, were built by Nissan and featured the stock iron block and aluminum heads of the original engine, but Knepp designed, developed and reprogrammed the engine's sophisticated electronic brain. This engine was named the 3.0-liter VG30 and, in 3.2-liter twin-turbo alloy-block (Electramotive cast) configuration, was also used by Nissan in their March-based Group C cars. The Bodywork of the American GTP car was designed by Yoshi Suzuka.
Appearing first of all at Laguna Seca in May 1985, the Nissan ZX-T was not successful in its first year, but in 1986, at Portland, Geoff Brabham won pole. He and Elliot Forbes-Robinson led the race only to run short of fuel with just two laps left. Stopping for a top-up, they finished third.
The effort was in full swing by 1987, more chassis arriving from Lola and development was ongoing: a Hewland gearbox replacing the original Weismann transmission. At Miami in early 1987, the car won at last. Brabham and Forbes-Robinson took pole and beat Rahal and Mass' Porsche 962. Electramotive Nissans took four more pole positions but no more victories that season. The Nissans were fast but unreliable.
In 1988, Jim Chapman's JC Prototypes built a new chassis, designed by Trevor Harris, to take the older car's running gear and bodywork. Goodyear tires replaced the Bridgestones previously used. IMSA had introduced new regulations to restrict the tremendous horsepower which was beginning to be seen from the turbo-engined GTP cars. Restrictor plates had to be fitted to engine intakes, IMSA reasoning that the horsepower advantage would now go in the favor of the big American V8s. Nothing daunted, John Knepp built an electronically-controlled turbocharger wastegate into the engine management system. This much-copied wastegate was the key to the team's success. In desperation, in mid-season, IMSA made another rule change, which gave the pushrod cars an extra weight advantage but it made little difference.
Nissan dominated IMSA racing in 1988, much to the dismay of the newly-arrived TWR Jaguars. Knowing that their strength lay in the shorter sprint races, Electramotive avoided the early races at Daytona and Sebring. But after that, Geoff Brabham, using the new chassis "8801" , won almost every race, taking nine wins (including eight in a row), usually partnered by John Morton. Nissan won the manufacturers" title and Geoff Brabham became the IMSA GTP Drivers" Champion.
1989 was very much a repeat of 1988. A second Chapman chassis "8802" had been built and delivered to Electramotive. The opposition was in disarray, as Porsche were now fading from the scene with the 962, Jaguar were developing their new XJR-10 V6 turbo and Dan Gurney's Eagle Toyotas were still on the learning curve. Nissan and Brabham were champions again.
Devendorf's team, by 1990, had been reorganized and re-titled "Nissan Performance Technology, Inc." (NPTI). The lightweight Eagle Toyotas were now showing themselves as the main threat even though Jaguar were providing slightly better opposition, but the ZX-Ts still dominated. Both Nissan and Brabham kept their championships. Halfway through the year, an all-new NPT90 car, still using the VG30 engine, was debuted and ran concurrently with the older car. Just one month after its first race, it was driven to victory at Mid-Ohio in June, by Derek Daly and Geoff Brabham.
NPTI took delivery of two Lola-built Group C R90CKs with VRH35Z engines in 1990 and took them to Le Mans as part of Nissan's 7-car attack, but both retired.
DESIGN / TECHNICAL SPECIFICATIONS
PLANS and DETAILS
- Nissan VG30 3.0L Turbo
60-degree V6, blown, water-cooled.
Single Garrett TO3 turbocharger. 87.0 x 83.0mm / 2958.9cc.
Iron block, aluminum heads. Wet iron liners, 4 plain main bearings.
Steel con rods.
Ross light alloy pistons.
Sealed Power rings. SOHC belt driven. 2 valves / cylinder (44.07mm inlet, 35.05mm exhaust), 1 plug. Compression ratio 8.5:1.
Semi-stressed chassis member. Maximum rpm: 9,000.