From the June 1995 issue of Car and Driver.

Nissan 300ZX Turbos have ranked high on our list of favorites since the model's debut in 1989. Offering 300 horsepower, enduring style, and an excellent mix of comfort with control, the 300ZX stands out as a versatile sports car.

Yet if you could suggest improvements for this Z-car, what would you choose? More power? It may not require much extra. Fresh styling? But excessive changes could diminish the Z-car's natural grace. Handling perhaps? The vehicle already corners sharply like a racer and delivers a firm ride when its adjustable shocks are set to sport mode.

Improving such a well-engineered car demands caution. Stillen Motorsport followed this careful path with its version, named the SMZ. Founder Steve Millen has long raced and tuned Nissans. In 1992 we sampled a Stillen-modified 300ZX convertible that previewed many styling elements seen on this newer effort.

Though it shares traits with that convertible, the SMZ differs in key aspects. It is a turbo coupe created with Nissan's North American team for sale through dealerships as a full package. It carries the factory warranty and costs about $14,000 above the standard 300ZX Turbo.

Setting aside the tall rear wing, Stillen's exterior updates stay understated. The new wing actually improves rear visibility compared with the stock spoiler. Paired with Yokohama wheels, the changes feature a mock-louvered front panel, a bolder front air dam, and fuller rocker panels plus a revised rear valance.

Inside, carbon-fiber trim covers the door handles, console, and shifter knob. The driver also finds large alloy pedals with black inserts that aid heel-and-toe shifts, though a larger foot may occasionally touch the throttle while braking.

Turning the key highlights Stillen's engine work. A revised intake and filter enhance airflow, while a free-flow exhaust adds a deeper note. With an added 2 psi of boost, output rises by 65 horsepower per Stillen.

Any concerns from the stronger exhaust fade once underway. The car remains flexible and pulls away smoothly, even in second gear without issue.

At higher revs the upgrades shine. Hard launches create tire smoke and strong acceleration. The extra boost can spin the rear wheels in second gear despite wide Yokohama tires on 9.5-inch rims. Midrange torque feels stronger with quicker boost response and added top-end pull.

These changes yield a 0.3-second quicker sprint to 60 mph and a 0.2-second better quarter-mile time than the stock Turbo. More noticeable is the improved flexibility shown in the 5-to-60 mph test, where the SMZ gains half a second. Highway passing runs also improve, reflecting the responsive midrange.

Suspension changes prove more pronounced. Stiffer springs and bars make the SMZ feel firmly planted. Grip rises to 0.92 g on the skidpad from 0.89 g, and our tester noted excellent limit behavior uncommon in modified cars.

The firmer setup sharpens the already quick steering yet maintains straight-line stability. On Michigan's rutted roads, however, the wide front tires cause the car to wander in grooves.

Unchanged shocks combined with stiffer springs and lower tires transmit bumps more directly than stock. Still, the ride stays acceptable for this class and close to a standard Turbo. The suspension switch works best in touring mode for daily use.

As noted earlier, a successful conversion preserves the 300ZX's usability. Stillen largely achieves this with the SMZ. Wet-weather manners remain a weak point, now slightly worse due to the firmer suspension and performance tires. Tail-out behavior can feel more sudden, though recovery stays predictable. Caution is advised on slick roads with any powerful rear-drive sports car, especially given Nissan North America's endorsement of this upgrade.

Specifications

Specifications

1995 Stillen SMZ 300ZX
Vehicle Type: front-engine, rear-wheel-drive, 2-passenger, 2-door coupe

PRICE
As Tested: $57,000 (est)

ENGINE
twin-turbocharged and intercooled DOHC 24-valve V-6, iron block and aluminum heads, port direct fuel injection
Displacement: 181 in³, 2960 cm³
Power: 365 hp @ 6400 rpm (mfr est)
Torque: 332 lb-ft @ 3500 rpm (mfr est)

TRANSMISSION
5-speed manual

DIMENSIONS
Wheelbase: 36.5 in
Length: 169.5 in
Curb Weight: 3602 lb

C/D TEST RESULTS
60 mph: 5.3 sec
100 mph: 13.5 sec
1/4-Mile: 14.0 sec @ 102 mph
130 mph: 25.8 sec
Rolling Start, 5-60 mph: 6.1 sec
Top Gear, 30-50 mph: 10.5 sec
Top Gear, 50-70 mph: 8.2 sec
Top Speed (gov ltd): 155 mph
Braking, 70-0 mph: 187 ft
Roadholding, 300-ft Skidpad: 0.92 g

C/D FUEL ECONOMY
Observed: 16 mpg

C/D TESTING EXPLAINED