Enthusiast's Buying Guide: Nissan 300ZX

The 300ZX Turbo was the embodiment of brains and brawn. Introduced in 1989 as a 1990 model, the fourth-generation turbocharged car received rave reviews from the automotive media and sent Corvette designers scrambling to meet the Nissan's 300 hp.

Although the twin-turbo Z sales were initially strong, approaching 40,000 units in 1996, in its final year of production, it's estimated that less than 4,000 units made their way into garages across America.

Despite being out of production for seven years, the twin-turbo Z still looks great, the technology was topnotch and the aftermarket continues to pay homage to the model. Nicely preserved 300ZX Turbos aren't hard to find, and prices have come within reach of most enthusiasts. Use this guide to find yours.

Bodywork
Even now, the fourth-generation car's appearance is both fine and refined. At its introduction, it was noted the third-generation's boxy shape and pop-up headlights that screamed "ChiPs" at primetime were gone. The new look was low and wide with smooth lines and a rounded roofline. The twin-turbo Z also had staggered wheel and tire sizes--wider in the rear than the front--which gave the car a menacing stance.

Bodywork for the twin-turbo, which was only available as a two-seater, was essentially the same as the normally aspirated Z, which was available as a two-seater and a 2+2; however, there were a few differences. The Z wore a small rear spoiler, which grew larger in 1994, and three small slat-like grille openings on the corners of its front spoiler. Also, the label Twin-Turbo, albeit small, can be found on the right rear of the decklid.

Turbocharged cars were also available with T-tops or a solid roof. We recommend, for added handling stability, going with the non-open car when possible.

Engine
The 3.0-liter 60-degree V6 of the third-generation Z remained--in title only. For the fourth generation, Nissan kept the iron-block and aluminum head configuration, but the block was redesigned and the crank, intake and exhaust manifolds, heads, valvetrain, electronics, and boost system were changed.

Performance at low and mid-range rev range was improved without sacrificing any top-end performance, thanks to the intake valve-timing control system. Peak torque was 283 lb-ft at 3600 rpm. One thing to note: The 1996 model dropped the variable valve timing due to smog regulations.

According to Steve Mitchell, who's worked with Nissan for 15 years, OBDII required the car's computer to not only monitor the fact the variable cam timing had changed, the regulations also required the ECU to monitor the exact position of the camshaft in adjustment range. The cost to update the ECU and add the sensors to the engine was too high for the final year of production. While officially the horsepower still hovered at the 300 mark, Nissan enthusiasts acknowledge the unofficial level was more like 280 hp.

Transmission
The rumored six-speed never came to fruition. Five-speeds, along with automatics, were offered all seven years of production. The five-speed is controlled by a perfectly placed short throw shifter.

Brakes
The ABS stock brakes were big for the time, with 11-inch, four-piston discs in front and 11.7-inch, two-piston discs in the rear. These brakes are still sufficient for street use, but fall short on the track. According to Mitchell, the brake calipers switched from aluminumto cast iron in 1993 in order to solve a warping issue.Brake pad upgrades to semi-metallic or carbon-metallic are a good idea, along with changing to stainless-steel brake lines. A better brake fluid with a higher boiling point is also recommended by many weekend racers.

Steering and Suspension
If the 300ZX Turbo's suspension was a crude DVD, it would be "Nissan Engineers Gone Wild." All Turbos came with four-wheel independent suspension, two-position cockpit adjustable shocks and Super HICAS four-wheel steering system, which tosses out a dose of opposite steering in the rear, immediately followed by same-direction rear steering.

Below 20 mph and above 75 mph, the system is inactive, but between 20 and 75 mph, it moves the rear wheels up to 1 degree, depending on vehicle speed, steering wheel angle, and the speed the steering wheel is turned. Turn the wheel quickly, and you get more of a response.

Until 1993, HICAS was electro-hydraulic, but for the 1994 model year, the system was changed to an electric rear rack for a small weight savings. Today, most die-hards disable it for track use.

The adjustable suspension had Sport and Touring settings. Additionally, the suspension geometry in the rear discouraged any squat at drag starts; in fact, it could produce a bit of annoying wheel hop. Stiffer lowering springs help.

What to look for
Like any car, there are some things to consider when looking to purchase a fourth-generation 300ZX Turbo. Mitchell recommends looking for one with lower mileage. The difference in price may pay for itself. If you're going to modify the vehicle, however, the car's mileage is less important, so consider your goals before shopping.

When you're looking over vehicles, he also recommends checking the wiring harnesses, which are particularly suspect in a car of this age, vulnerable to heat, time and age.

Look for latter production cars; by then, some of the bugs, like a drippy brake master cylinder or problematic VTC springs that are more

common in the earlier production models, had been dealt with. As well, there was one recall with the fourth-gen model: an ignition system power unit. When shopping around, check that the car's owner has a record of this service.

Also, take a second to make sure the ignition coils are firing. When the engine is running, you should hear a faint rapid ticking as they fire. Any discrepancy in the firing rhythm may indicate one of the coil packs has gone bad.

Another problem, according to Mitchell, are the clutch throwout bearings, which when worn, make a lot of noise. The clutch in a 300ZX Turbo should be good, if it hasn't been abused, for about 70,000 miles.

All cars have an Achilles heel. For the 300ZX Turbo, it was the alternator. You'll likely have to get a new one if it hasn't been replaced already. Sixty grand on the odo? Better also have the timing belt changed or you'll live to regret it. And so will your wife. And your kids. And your kids' kids.

Looking for a project car? According to Adam Lotz, who maintains an enthusiast Web site on the Z32, the preferred years would be '91-'95; the '94-'95 are the most desirable--and the most expensive. Anything from 1996 is hard to find because of low production numbers, and the earlier Z32s are subject to some minor technical issues. Technical Service Bulletins may give you some indication as to any other things that may influence your purchasing choice. You can find these at www.nhtsa.dot.gov/cars/problems.

Year-to-Year Changes*
1990: Totally new fourth generation. Introduced in 1989 as a 1990 model.
(Colors not known)
1991: Available as a two-seater without a T-bar roof; centered "hamburger" logo added between headlights. Logo on floor mats changed to "Z". CD added for an option on the TT; previously, it had only been available on the naturally aspirated version. No more ambient temperature gauge. Manual climate controls are eliminated except for on the 1993 convertible. (Aztec Red)
1992: Driver-side airbag now standard, cloth seats, power door lock mechanism is all-new. Power driver's seat and leather-covered automatic transmission shift lever become standard on T-bar roof models. Change from woven interior cloth to a suede-like interior. Mirror heater switch is eliminated; instead, it's combined with the rear defroster switch. (Super White, Cherry Red Pearl, Ultra Red, Onyx, Glacier White Pearl, Oxford Gray, Sapphire Blue, Silver Ice Metallic)
1993: Brakes switched from aluminum to cast iron, convertible model--for those who like bugs in their teeth--is introduced. Air Induction Valve dropped--a part that no one missed. (Super White, Cherry Red Pearl, Ultra Red, Cocoa Bronze, Onyx, Glacier White Pearl, Platinum, Oxford Gray, Sapphire Blue)
1994: Seatbelts redesigned, mounting to B pillar instead of door itself. HICAS electrically instead of hydraulically driven. Rear spoiler design changed and keyless entry introduced. (Super White, Cherry Red Pearl, Ultra Red, Black Emerald, Super Black, Glacier White Pearl, Platinum, Sapphire Blue)
1995: Windshield washer reservoir relocated to under the hood instead of in the trunk. Front facia becomes body colored, instead of being a gray strip. (Colors not known)
1996: OBDII requires Nissan drop the variable cam timing, causing the 300ZX to unofficially lose 20 hp. The driver's seat back no longer includes adjustable side bolsters. (Arctic White Pearl, Platinum Metallic, Ultra Red, Cobalt Green Pearl, Deep Purple Metallic, Sapphire Blue, Super Black)
*Information in part supplied by www.fiendation.com/300ZX.htm, www.zhome.com, wwwz32.org