There are some cars which, despite an unsuccessful start-limitation by the rules of the day, still manage to shine. This 1988 Nissan GTP-ZX is one of them. As shown by the footage above, it’s still frighteningly fast. Imagine what it was like thirty years ago, when the IMSA board shackled it with restrictions.
In an attempt to level the playing field between the turbocharged cars and the atmospheric cars, IMSA introduced mandatory 57mm-diameter inlet restrictors for the force-fed engines. This deprived the Nissan’s VG30ET V6 of roughly 200 horsepower, though it still made somewhere around 800 horsepower in race trim, with roughly 25 pounds of boost.
As the majority of races on the IMSA GTP calendar were set on city circuits, some drivers — notably those driving the naturally-aspirated Jaguars — felt the Nissans would struggle in the cramped conditions. Ironically, the restrictors increased torque lower in the rev range, which allowed the wide Nissan (nearly 80 inches across the hips) to be driven quickly, accurately, and consistently around the point-and-shoot hairpins at places like Miami and Del Mar.
It also put that power to the ground very well. With a single turbocharger, over 750 lb-ft of torque, and a mule-kick power delivery, one would assume the rear Goodyears would spin at every prod of the throttle. However, the GTP-ZX launched out of the slowest corners with the traction of a four-wheel-drive machine. Massive 350-section tires at the rear helped there, but so did the wild ground effects.
To ensure constant downforce, they needed a stable aerodynamic platform. Therefore, the car was run quite stiffly — so stiff a front swaybar was unnecessary. This made the car a pig in the slower corners. To counteract the understeer, a little toe-out in the rear was necessary. At high speeds, the car was at its best — as evidenced by the puckering speeds Theo Bean carries through Turns 12 and 1 at Road Atlanta in the lead video. The outrageous stick made it special, but the relentless acceleration made it extraordinary.
Whereas the Chevy Intrepid — a rival powered by an atmospheric V8 — runs out of steam towards the end of Road Atlanta’s long straights, the Nissan pushes on, unfazed by the drag. Bear in mind that, in this footage, the car is running on low boost. With the wick turned up, it’s happy to make 900 horsepower — and it only weighs 2,100 pounds!
Strong in most departments, the GTP-ZX suffers in one area: visibility. The right-side mirror is inline with the a-pillar and there’s no rear window. The mirrors are convex to help, but they don’t provide the driver with much information. Even the windshield is quite small. However, that’s excusable, since the car was designed to be quick in high-speed sections over all else.
Its successful development and the team’s methodical hard work were reflected in its results from the 1988 season: 9 wins, 8 poles, 10 fastest laps, and the IMSA GTP Driver’s Championship for Geoff Brabham, even having skipped Daytona and Sebring. Simply incredible.
Even more incredible: its ability to run with modern LMP cars. Watching this, you have to pinch yourself — this machine was racing at its peak during the Reagan administration.