From the June 1995 issue of Car and Driver.
Nissan 300ZX Turbos have been high on our hit parade ever since this model's introduction in 1989. With 300 horsepower, timeless good looks, and a fine balance of comfort and command, the 300ZX is a truly versatile sports car.
But if you had a voice in an improvement exercise for this Z-car, what would you add? Power? Maybe, but it doesn't need much more. Styling? Okay, but too much of a makeover might spoil the Z-car' s underlying elegance. What about handling? The car already turns in like a race car and has a fierce ride with its two-position shocks set on "sport."
So how do you improve a car that has been so thoughtfully developed? The answer is, very carefully. And that appears to be the approach Stillen Motorsport adopted with its Z-car, called the SMZ. Company founder Steve Millen has been racing and modifying Nissans for years. Back in 1992, we drove a Stillen-modified convertible 300ZX, a car that already flaunted many of the styling cues you see here on his latest project.
Despite some similarity to the convertible, the SMZ is unique in a number of ways. First, it's a turbocharged coupe. Second, it was developed in cooperation with Nissan's North American operations to be sold at Nissan dealerships as a complete package, with the same warranty as a factory car, for around $14,000 more than the factory 300ZX Turbo.
If you can overlook the tall rear wing for a moment, Stillen's upgrades to the exterior are rather subtle. And even the replacement wing proves more practical than the original low-profile tail spoiler because it does not block rearward visibility. Along with the Yokohama wheels, Stillen's makeover includes a mock-louvered nose panel, a more aggressive front spoiler, and voluptuous rocker-panel and rear valance plastic.
Inside the car, a major change is carbon-fiber cladding on the door-handle surrounds, the center console, and the gearshift knob. Then, sliding down into the seat, the driver notices the big alloy pedals with black metal inserts. They're nice to look at, and helpful during heel-and-toe exercises, but a size-11 foot occasionally blips the throttle as it applies the brakes.
At the twist of the key, the results of Stillen's various engine mods become apparent. A new intake manifold and air filter improve the car's breathing, while an aluminized steel free-flow exhaust system gives the Stillen a more authoritative burble than the stock 300ZX Turbo makes. Together with an extra 2 psi of boost, these changes produce 65 more horsepower, according to Stillen spokesmen.
Any misgivings that virile exhaust note might raise about the car's drivability are erased as soon as you step off the clutch. The Z-car's flexibility is undiminished, and the SMZ moves off with docile ease. In fact, it will pull away happily in second gear.
Higher in the rev range is where the Stillen engine revisions reveal themselves. Full-throttle launches produce plenty of tire smoke, axle hop, and furious acceleration. On anything other than a scrupulously clean surface, the Stillen SMZ's two extra pounds of boost will spin the rear wheels in second gear. This despite the 275-section, 35-series Yokohama AVS donuts embracing the 9.5-inch-wide rear rims. The engine is distinctly muscular in midrange, with what feels like a faster onset of boost and quite emphatic improvement in high-rpm thrust.
On paper, these translate to a 0.3-second improvement over the last standard ZX Turbo during sprints to 60 mph, and a quarter-mile performance better by 0.2 second and 1 mph. Modest accomplishments, to be sure, but they're not the whole story. The car's enhanced flexibility is demonstrated in our 5-to-60-mph street-start test, where it's a half-second quicker than the stock Z-car. The SMZ also shows its torquey midrange response in top-gear 30-to-50-mph and 50- to-70-mph tests, where it runs 10.5 and 8.2 seconds, compared with 10.9 and 8.9 seconds for the stock car. These are improvements you can feel out on the highway a quicker throttle response.
Stillen's suspension upgrades are less subtle than the engine mods. Wearing higher-rate springs and stiffer anti-roll bars, the SMZ feels very tightly constrained. The extra control and the bigger tires provide 0.92 g of skidpad grip, up from the usual 0.89, and prompted a comment by our tester that "the SMZ is excellent at the limit—uncommon for a tuner car."
The tauter chassis emphasizes the Z-car's extremely quick off-center steering response, yet the car still tracks like a train. Unless, that is, there are truck ruts. Here in Michigan, the car darts and jinks like a prison bloodhound as its wide 255/40ZR-17 Yokohama AV1-40 front tires roam our asphalt gullies.
Although the 300ZX Turbo's two-position shocks are unchanged in the Stillen SMZ, its harder springs and lower-profile tires transmit road topography a little more abruptly than the standard car. But we think the SMZ remains, by and large, acceptable for a car of this type, and not too much different from a normal 300ZX Turbo. Like that car, it feels reasonably cushioned at speed, where its strong body and intelligent suspension geometries take the edge off the worst bumps. Also like the stock vehicle, its two-position suspension switch is best left on "touring" unless you're really in a hurry.
As we stressed at the outset, the key to producing a successful 300ZX conversion is not to compromise its practicality, and Stillen seems to have gotten most of that right with the SMZ. The Nissan 300ZX was never a wonderful vehicle in bad weather, and this remains true of the SMZ. In fact, with it tighter suspension and high-performance rubber, it's probably worse. The tendency Z-cars have to hang out the tail when the boost overtakes the grip seems more abrupt than ever, even though the SMZ was just as quick to recover once the usual techniques were administered. But don't play boy racer on wet roads in this or any other strong rear-wheel-drive sports car. Not unless you're Steve Millen, whose prodigious driving talents helped set this car up with the quick-but-predictable handling we observed. Nissan North America wouldn't stand behind just anybody's 300ZX Turbo upgrade, you know.
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
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