Tested: 1990 Nissan 300ZX Turbo Rises to the Top

From the November 1989 issue of Car and Driver.This fall’s bumper crop of new Japa­nese cars must come as a shock to many auto analysts—at least those who expect­ed the rise in the value of the yen three years ago to provide relief for the rest of the world’s automakers. Not only are the Japanese moving into the new model year with the usual allotment of ever more competitive models, but they’re now armed to take on the world’s most established and prestigious automotive brands. As proof, we present one of the most potent weapons in that arsenal: the new Nissan 300ZX Turbo.Brace yourselves, sport fans: what we have here is nothing less than the first Japanese sports car able to run with the big dogs. Whether you’re comparing acceleration, roadholding, or top speed, the Turbo Z has the qualification need­ed to compete against the likes of the Chevrolet Corvette, the Porsche 911, and even the Ferrari 328.
Feast your eyes on the performance figures we measured with our five-speed-­equipped, pre-production test car: 0 to 60 mph in 5.5 seconds, the standing quarter-mile in 14.1 seconds at 99 mph, a top speed of 153 mph, lateral accelera­tion of 0.89 g, and a 70-to-0-mph stop­ping distance of 175 feet. The only car in the world that can better this perfor­mance are high-buck exotics. The 300ZX Turbo lists for $33,000. At a glance, the Turbo looks virtually identical to its normally aspirated sibling. The only visible differences are the Tur­bo’s small rear spoiler, fat rear tires, and larger front air dam with subtle vents on each side. Don’t be fooled, though: the minor exterior revisions cloak a host of significant mechanical upgrades.
The most important of these is the in­vigorated engine. Nissan engineers have grafted twin turbochargers and inter­coolers onto the new Z’s four-cam, 24-valve, 3.0-liter V-6. Not one of these new pieces is visible in the 300ZX’s crowded engine bay: The intercoolers are wedged into body cavities immediately forward of the front wheel wells, and the turbos­—one for each bank of three cylinders—are tucked below and behind the engine. About all you can see are the ducts that direct the intake air in its various states of compression. A reduction in compression ratio from 10.5:1 to 8.5:1 helps the engine resist the detonation that a peak boost pressure of 9.8 psi can precipitate. Should the engine’s knock sensor detect any untoward combustion, the electronic engine-con­trol system can reduce boost pressure or retard ignition timing. Recirculation valves in the intake tracts help keep the twin water-cooled AiResearch turbos spinning near full boil when the throttles are briefly closed. The blown engine also receives oil-cooled pistons, larger fuel injectors, stouter con­necting rods, cast-iron exhaust manifolds, recalibrated camshafts, an engine-oil cooler, and exhaust valves carved from temperature-resistant Inconel alloy.
All of these changes add up to a claimed 300 hp at 6400 rpm and 283 pound-feet of torque at 3600 rpm. When mated to the optional automatic transmission, the engine receives different camshafts and smaller turbochargers, which boost low-rpm performance but extract a 20-hp penalty. More on the Nissan Z From the ArchiveBoth the five-speed and the automatic are modified to cope with the turbo­charged engine’s power. The manual gearbox, the same basic unit introduced on the naturally aspirated 300ZX, is equipped with reinforced second and fifth gears. To transfer the increased out­put to the transmission without slippage, Nissan engineers increased the clutch pressure from 1232 pounds to 1760. Then, in order to keep clutch-pedal ef­fort at manageable levels, they fitted a vacuum power booster (similar in con­cept to a common power-brake booster) to the clutch linkage. The automatic box is a beefed-up ver­sion of the electronically controlled transmission used on the naturally aspi­rated car. It communicates with the engine-control computer, which retards ignition timing momentarily during shifts for greater smoothness. With either transmission, the Turbo receives a larger differential fitted with the same viscous-­coupling limited-slip device found on the regular 300ZX. The suspension also received a thor­ough reworking to help it cope with the Turbo’s increased power and speed. The Turbo Z wears sticky, Z-rated rubber all around; the fronts remain 225/50-16s on 7.5-inch-wide wheels, but the rears in­crease to 245/45-16 on 8.5-inch wheels. The Turbo also gets stiffer springs, shock absorbers, and suspension bush­ings. To mitigate the effects of these changes on ride comfort, the shock offer two damping positions, controllable by a switch on the center console.The Turbo also benefits from “Super HICAS,” Nissan’s designation for the latest iteration of its four-wheel-steering system. Unlike the 4ws systems offered by Honda and Mazda, Super HICAS pro­vides no benefit in parking-lot maneuverability. Its maximum rear-wheel steer­ing angle of one degree is tailored exclusively to improving the car’s han­dling at speed.At the beginning of a corner, Super HICAS briefly turns the rear wheel in the opposite direction of the front wheels, thereby helping the car bend crisply into the corner. Then, as corner­ing progresses and the car begins to ro­tate, the system turns the rear wheels in phase with the fronts. This in-phase four­-wheel steering helps to reduce tail­-swinging and promote stability. A computer determines the exact de­gree and timing of the rear-wheel steer­ing by monitoring inputs from sensors that measure speed and steering-wheel motion (steering angle, steering-angle velocity, and steering-angle acccleration). The HICAS computer steers the rear wheels by regulating solenoid valves that direct fluid flow to a hydraulic cylinder behind the differential. The cylinder in turn moves a set of tie-rods leading to the rear wheels. It all sounds very complicated, but you never sense anything unusual or artificial from the driver’s seat. In fact, the 300ZX Turbo responds to steering inputs as ac­curately as any car we’ve ever driven. Steering effort is just about perfect at any speed, straight-line stability is excellent, and the car bends into corners without any high jinks from the tail. Whether you’re toodling to the grocery store or imitating Alain Prost, the 300ZX does your bidding effortlessly. Of course, the rest of the suspension also deserves some credit for the Turbo’s superb road manners. The suspension signals the approach of its lofty 0.89-g cornering limit with gentle, reassuring understeer, although trailing the brakes or applying a strong dose of throttle can bring the tail around. The Turbo also has outstanding longi­tudinal traction. Most cars that accelerate as hard as the 300ZX Turbo demand a deft touch on the throttle when cornering in the lower gears. But the Z’s ad­vanced suspension and viscous limited-­slip differential transfer the power to the ground surely and effectively.
The engine’s smooth power delivery doesn’t hurt, either. Unlike those turbocharged engines that explode onto boost as if a second engine had cut in, the twin-­turbo V-6 builds boost smoothly and progressively. That is not to say slowly, for the Turbo’s 10.6-second 30-to-50-mph top-gear acceleration time suggests that boost begins to build at very low rpm. At the other end of the rev band, the V-6 pulls cleanly to its 7000-rpm red­line in every gear except fifth, at which point the engine-control computer pro­gressively cuts fuel flow to the cylinders to limit top speed to 153 mph. The Turbo is equally impressive in hard running and relaxed cruising. Set in the Touring position, the suspension is reasonably supple for such a high-perfor­mance car; the ride is at least as good as any in this class. The stiff body structure helps achieve that composure. Even equipped with the standard T-tops (which Nissan has unfortunately decided to bestow on all U.S.-market 300ZXs), the body remains free of creaks and rat­tles on any road surface. A boost gauge has been added and the upholstery is slightly different, but the 300ZX Turbo’s interior is otherwise the same as the naturally aspirated car’s. And that’s good. Visibility to the rear quarters is a bit restricted, but the new Z’s cockpit is otherwise just about perfect. We do wish the car weren’t so heavy, however. The additional equipment on the Turbo brings its weight up to a hefty 3501 pounds—about 250 pounds heavier than a Corvette. And despite the Turbo’s fine showing at the test track, our calcula­tions indicate that the turbocharged en­gine actually produces 20 or 30 hp less than Nissan’s claim of 300 hp. Still, these are nit-picking complaints given the Tur­bo’s performance, solidity, and excellent (for a high-performance car) EPA city fuel-economy rating of 18 mpg.The Turbo commands a $5000 premi­um over the naturally aspirated Z, but we think the extra cost is justified. The Tur­bo’s $33,000 base price includes all of the performance goodies; you pay extra only for such features as an electronic cli­mate-control system, a power seat, or leather upholstery. And considering that the 300ZX Turbo promises to be one of the best all-around GTs on the market, $33,000 is bargain fare.SpecificationsSpecifications
1990 Nissan 300ZX Turbo
Vehicle Type: front-engine, rear-wheel-drive, 2-passenger, 2-door hatchback
PRICE

Base/As Tested: $33,260/$33,260
ENGINE
twin-turbocharged and intercooled DOHC 24-valve V-6, iron block and aluminum heads, port fuel injection
Displacement: 181 in3, 2960 cm3
Power: 300 hp @ 6400 rpm
Torque: 283 lb-ft @ 3600 rpm 
TRANSMISSION
5-speed manual
CHASSIS

Suspension, F/R: control arms/multilink
Brakes, F/R: 11.0-in vented disc/11.7-in vented disc
Tires: Michelin MXX
F: 225/50ZR-16
R: 245/45ZR-16
DIMENSIONS

Wheelbase: 96.5 in
Length: 169.5 in
Width: 70.5 in
Height: 49.2 in
Passenger Volume: 52 ft3
Cargo Volume: 10 ft3
Curb Weight: 3501 lb
C/D TEST RESULTS

60 mph: 5.5 sec
1/4-Mile: 14.1 sec @ 99 mph
100 mph: 14.6 sec
130 mph: 30.9 sec
Top Gear, 30–50 mph: 10.6 sec
Top Gear, 50–70 mph: 8.8 sec
Top Speed: 153 mph
Braking, 70–0 mph: 175 ft
Roadholding, 300-ft Skidpad: 0.89 g 
C/D FUEL ECONOMY

Observed: 15 mpg
EPA FUEL ECONOMY
City/Highway: 18/24 mpg 
C/D TESTING EXPLAINEDCsaba Csere joined Car and Driver in 1980 and never really left. After serving as Technical Editor and Director, he was Editor-in-Chief from 1993 until his retirement from active duty in 2008. He continues to dabble in automotive journalism and WRL racing, as well as ministering to his 1965 Jaguar E-type, 2017 Porsche 911, 2009 Mercedes SL550, 2013 Porsche Cayenne S, and four motorcycles—when not skiing or hiking near his home in Colorado. 
Source: caranddriver.com