Nissan GT R Package and Engine

vehicles has been focused on the static load distribution during stopping. However, to ultimately heighten the fundamental performances of "driving, cornering, braking" , inertia load shift has been fully separated and independent between the front and rear wheels; the engine load on the front tires and transaxle load on the rear. In addition to this, the transaxle placed below the rear wheel center lowers the center of gravity of the vehicle. The Nissan GT-R, capable of utilizing inertia load, realizes ultimate flat riding comfort with minimal load shift during braking, cornering and any driving situation.

The basic dimension of the vehicle has also been optimized. Run-flat tires with a large diameter and high capacity have been adopted to maximize the tire grip area where power and torque are applied, and optimize power weight and torque weight ratio. Heavy load is placed in the center of the vehicle based on the wheelbase tread.A brake with powerful braking force, is adopted to handle " driving and cornering" . The optimized dimension realizes balanced load distribution on all four wheels, improved cornering performance and stability, pitching convergence, damping force and braking force improvement, and minimized shift in posture.

As load distribution is evenly balanced on all four wheels with the optimized load distribution and dimension, vehicle behavior is easy to grasp, allowing the driver to start accelerating earlier. In addition, powerful traction of the front wheels helps the vehicle to accurately accelerate in the steered direction. With this newly created " traction steering" driving concept, the fun-to-drive range is widely expanded.

2-2. Balanced combination of powertrain cooling performance and aerodynamics

The newly developed Premium Midship Package has achieved a balance in the improvement of aerodynamics and cooling, two contradictory performances of the powertrain. The Nissan GT-R designers moved the transmission from just behind the engine to the rear. Cooling air passes over the engine, enters a space where the transaxle would normally be, then passes through the floor tunnel to cool the transaxle. This cools the powertrain far more efficiently. Creating this flow from the engine room to through the floor tunnel enables downforce air control under the floor, just as a racing car.

Working 2 years with Group Lotus in Europe to develop more efficiently, and 1.5 years with Yoshitaka Suzuka in Japan for aerodynamic development using moving belt systems, the vehicle has successfully balanced low air-resistance (Cd:0.27) and greater downforce - something formerly believed to be impossible - to realize aerodynamic performance on a par with racing cars. Higher front and rear downforce gives the Nissan GT-R better grip, improves active safety performance, reduces air resistance (Cd:0.27) and raises fuel-efficiency.

The wind noise during high-speed driving has been reduced by careful reconsideration of the form of each body part. The under floor noise is controlled with the minimized floor through-hole and rectification due to vehicle undercover. This allows the driver to drive at 300km/h on the Autobahn and still enjoy conversation with the person in the passenger seat.

2-3. Reduced powertrain vibration

In the Premium Midship package which adopts an independent transaxle 4WD, powertrain vibration is highly reduced and durability potential at maximum speeds is highly improved. The engine and transmission are independently antivibration mounted, and the transmission placed further away from driver helps clear the engine sound and greatly reduces air noise around the driver seat. This quiet cabin in high-speed driving is made possible by preventing mechanic vibration noise that was formerly generated from the unified engine and transmission at around 4000 revs. The overall length of each the engine and the transaxle, which are separated/ joined by the high vibration damping carbon fiber propshaft, are shorter compared to the conventional FR-4WD vehicle. This highly improves powertrain durability performance at maximum speeds and increases the potential of high-speed driving.

<<3. Driving position and utility>>

In the Premium Midship package, the transmission has been moved from just behind the engine to the rear, expanding the foot space in the cabin and creating enough space to design an optimized pedal layout. Also, the adoption of run-flat tires helps to realize a larger and flatter trunk space.

Ideal driving position space for supercar drivers

Horizontal distance from floor surface to hip point: 200mm
Tilt mechanism from the base is applied to keep the steering wheel angle optimized
The steering position adjusts to optimized angle. (Tilt: 60mm; telescopicF 60mm)
The largest seat position coverage in supercar market
Long seat slide: 228mm, lift amount: 30mm
The best driving position from short females to tall males / 144cm-190cm
Optimized pedal layout for smooth operation
Pedal stroke extension: 65mm (Fairlady Z (Z33): 55mm)
Optimized pedal angle: 42.5 degrees (Fairlady Z (Z33):37.5 degrees)
Acceleration pedal surface slip amount: 4.3mm

To enable the driver to fully concentrate on safe driving especially at high speeds, the door mirror, combination meter and multifunction meter are positioned an uniformed height, minimizing the driver's eye movement while driving.

Thanks to the flat floor by abolishing the spare tire, larger trunk room than the other super cars is realized. 2 sets of golf bags (8.5 inches) or a pair of Special A size suitcase and C size suitcase can be loaded. (Trunk room height:435mm, length:850mm, width (maximum):1470mm)

Engine

Nissan's VR38DETT is a brand new engine specially developed for the Nissan GT-R. The 3.8-liter unit uses twin IHI turbochargers. Its maximum power is 480 PS (353 kW) at 6400rpm. This makes the Nissan GT-R one of the world's most powerful road cars and the most powerful production car ever built by Nissan.

'More important than the absolute power, is the manner in which it is delivered,' says chief vehicle engineer Kazutoshi Mizuno. 'The engine's very tractable and that means it's very easy to drive, a key quality of the Nissan GT-R.' Maximum torque of 60kg/m (588 Nm) is delivered seamlessly from 3200-5200rpm.

It is also a very efficient engine, reducing emissions and fuel consumption. The Nissan GT-R is the world's most efficient supercar in balancing speed, acceleration and fuel consumption. Environmental performance is further reinforced by its satisfying Japan's U-LEV (ultra low emission vehicle) standards.

The engine's high environmental standard is partly due to the innovative plasma-coating bores, which improves cooling, boosting fuel efficiency and power. The plasma sprayed cylinder liner bores are just 0.15mm thick, compared with conventional cast iron liners of 2.6mm. Not only are they much better at dissipating heat, improving efficiency, they're also lighter - saving about 3 kg in a V6 engine. To ensure sufficient lubrication of this sprayed-on cylinder liner in the aluminum block, special synthetic engine oil is used (Mobil-1 RP OW-40).

In addition, the fully independent intake and exhaust systems produce a higher output and a faster response. These fully symmetrical intake and exhaust systems increase air intake and reduce exhaust resistance, producing a smooth and fast gas flow. The twin IHI turbochargers are highly responsive.

Emissions are improved by a secondary air system, featuring an air pump, which promotes faster catalyst reaction, better to cleanse the exhaust.

The Nissan GT-R's advanced electronic controls respond quickly to climate and altitude changes, ensuring maximum performance at all times. Precise monitoring of the air-fuel ratio further improves fuel efficiency and emissions. This precise control improves high-performance fuel consumption by five percent. During ordinary low-rev driving, the Nissan GT-R will typically generate about 40 kg/m (392 Nm) of torque - sufficient for excellent pick-up and acceleration - and this high output allows for an optimum air-fuel ratio, significantly improving fuel efficiency and exhaust cleanliness. 'When driving on moderate throttle openings - in other words, in normal everyday driving - the Nissan GT-R proves to be especially ecologically friendly,' says Mizuno. 'Its fuel economy advantages over rivals is magnified in such normal everyday driving situations.' In automatic mode, the transmission quickly chooses high gear ratios, allowing the engine to ride along on a wave of low-rev torque.

Other technical innovations include a thermostatically controlled air-cooled type oil cooler system, for greater cooling efficiency. The engine oil is cooled by oil cooler system and in extreme cornering - of which the Nissan GT-R is easily capable - a scavenger pump maintains turbocharger oil flow. A collector tank inside the fuel tank always stores enough fuel to maintain fuel flow even under strong g forces. The oil collecting structure inside the engine is optimized by a lateral wet and dry sump system, which helps secure stable oil collecting and oil pressure in various driving scenes.The engines, like the transmissions, are all hand made. One craftsman hand-assembles the entire engine. The dedicated engine builders work in a special Nissan GT-R 'clean room' area of Nissan's Yokohama plant.

Date : 02 Nov 2007 13:15:04 Source: Nissan

Date : 02 Nov 2007 13:15:04
Source: Nissan