The Z-tunes are built on second-hand R34 GT-Rs, specially selected by Nismo. This is because Nissan stopped production of the Skyline GT-R in August 2002, therefore no new cars could have been supplied by the factory. This, of course, is not too relevant, as the base cars for the Z-tunes are completely stripped down and hand-built from the ground up. As the car bodies and chassis are prepared, the work on the 2.8 L RB26DETT get underway in the engine room at Nismo HQ. The Z-tune engine is built around the GT block, which is the extremely strong, thick-walled item used in the GT-500 cars that competed in JGTC. This block has proven itself time and time again and is reliable even for a highly tuned street car like the Z-tune. The engine is assembled with a special bottom end made up of a GT crank, GT connecting rods and forged pistons. With a capacity of 2,771 cc the engine gains more than 200 cc over a factory RB26 (2,568 cc), allowing for a fuller low-end torque curve and better spool-up for the turbines. The Z2 engine is built to very tight tolerances with high-quality Nismo bearings all round. Next on the cards is the porting and polishing of the cylinder heads, a step that requires many man-hours, not to mention skilled workmanship. The head is then fitted with the uprated valve-train and high-lift camshafts. To guarantee the highest possible reliability, the engine has been limited to 8,000 rpm (same as a factory RB26). IHI turbines are used to provide the boost necessary to develop the 500 hp. Juggling the power is a factory Getrag 6-speed transmission mated to a Nismo Coppermix twin-plate clutch and lightweight flywheel. A carbon propeller shaft sends drive to the rear reprogrammed A-LSD while up front a specially devised 1.5 way mechanical LSD juggles front torque. Other interesting parts include the full-dual titanium exhaust system and the gearbox and rear differential oil coolers.

A great deal of the price of the Z-tune comes from the painstaking attention to detail that has gone into the chassis and body preparation. Once the donor car is stripped down to the bare shell, it is spot-welded around the door and glass surrounds. This is done to boost rigidity in the central area of the chassis, something that's not really done - even on a stiff shell like the BNR34's. To further increase body rigidity in crucial areas, Nismo has gone all out and used carbon fiber. The carbon is bonded to the front suspension turrets and to the transmission tunnel to guarantee exceptional stiffness in these high-stress areas. Carbon is also used in the trunk to give additional rigidity to the rear end. The exotic composite material is further used in the bodywork, more specifically the front bumper, front fenders and vented hood. Even the adjustable flap on the rear spoiler is made from carbon fiber. The next step is body prep and painting. To add to the exclusivity of the Z-tune, Nismo decided to paint all 20 cars in a special shade of metallic silver, a shade that truly pops under the sun's rays.

The build continues with the suspension and brakes, which are just as special as the rest of the car. Nismo suspension arms are fitted all around; they aren't adjustable but feature a more aggressive geometry, additional bracing and stiffer bushes. All of these combine to sharpen up the handling and steering-feel. Custom built three-way adjustable Sachs dampers have been specifically developed by the German company for Nismo. They feature the same design used on race cars and are by far some of the best suspension pieces in the world. The same goes for the brakes. Nismo called in the help of Brembo, which designed custom 6-pot front calipers. These calipers feature an extremely compact design to fit under the Rays Engineering-made LM GT4 18-inch wheels, and are mated to 365mm slotted brake rotors mounted on custom made center bells via a fully floating system. The rears feature 4-pot Brembo calipers and 355mm one-piece rotors. High friction pads offer fade free braking in all conditions and temperatures.

The interior is kept very close to factory, with only a few choice parts making their way into the Z-tune. Connolly leather is used on the seats, while red alcantara inserts keep occupants from sliding around on the faster corners. The door panels and sports steering wheel are also finished off with the soft red suede. Nismo instrumentation with white background optimistically reads to 11,000 rpm on the rev counter, but the 320km/h max reading on the speedometer is a little more realistic. The LCD multi-function display has been upgraded to the Nismo Ver.2 software, which adds even more readings to the already impressive graphical layout. Completing the interior treatment is a black GT-style shift knob and a rather rudimentary head unit for the audio system. This has been chosen because it's believed most customers will upgrade to a better audio system.

On our final visit to Omori Factory we shot the fully completed n16 just minutes before it was due to be picked up by a special transporter to be taken to the Yokohama docks for shipping. The Z-tune was immaculate. It was all packaged up ready to go, like it had just rolled off the Nissan production line. By the time you read this, the lucky owner should be receiving his limited edition toy and then begin the lengthy process of registering the car.