Production of Infiniti’s all-new compact and lightweight V6 twin-turbo engine has started at Nissan Motor Co.’s state-of-the-art engine manufacturing facility, the Iwaki Plant in Japan.
The new V6 is to be offered exclusively in Infiniti models, and is described as ‘the lightest, most powerful, cleanest and most fuel-efficient V6 engine’ that the brand has ever offered. The first application of this engine family will be in the 2016 Infiniti Q50 sports saloon, before making its way in to other models such as the Q60 sports coupe (top).
“Infiniti is in the middle of a major product offensive, significantly expanding and refreshing our product portfolio. With the new V6 engine, Infiniti vehicles will become even more powerful and more fun to drive,” said François Goupil de Bouillé, vice president of Infiniti Europe, Middle East and Africa. “The experienced team at the Iwaki Plant will deliver the engines with the highest levels of quality for our customers across our EMEA region and around the world.”
The VR30 is an aluminum engine block (above), which has been constructed as a ‘square’ engine with equal cylinder bore and stroke dimensions (86.0 x 86.0mm). Displacing three liters, the V6 twin-turbo is available in two performance levels 304 or 405PS, and belongs to the ‘VR-series’ powertrain family, born out of the brand’s long-standing heritage of V6 engine production at the Iwaki plant.
The 304PS version is fitted with a single intercooler pump, while the 405PS engine uses two for more effective management of heat when under operating at higher loads. In addition, the high-output variant gains an optical turbo speed sensor to give an additional 30% power boost to the turbo system by allowing the turbine blades to spin faster.
These outputs have been achieved while ensuring an improvement in fuel efficiency of up to 6.7% and this represents a best-in-class power-to-efficiency ratio for the 400hp power unit.
Infiniti states that this power-to-efficiency performance was made possible thanks to a set of newly-developed features on the engine; advanced timing control ensures improved responsiveness, enabling quicker reactions to driver inputs, while a new electric motor is fitted to the valve timing system to help reduce throttle response times (below).
The V6 also features a new turbine speed sensor, which allows for the twin-turbo system to perform at up to 220,000rpm at steady condition and 240,000 rpm at transient condition, higher than ever before for a V6 power unit. With greater capacity for faster revolutions, the twin turbochargers boost the higher-powered version of the engine to deliver higher power and torque. The turbo speed sensor on the 400hp version allows for up to 30% more power output.
Infiniti has also developed an all-new, compact water-cooled intercooler system (above) to further boost performance and efficiency. By ensuring the system remains small, flow paths for air entering the system are reduced, further reducing ‘turbo lag’ and improving throttle response. A new electronic wastegate actuator allows closer control of exhaust gas flow away from the turbocharger, restricting the amount of exhaust gas flowing through the unit to improve overall engine efficiency.
The core structure of the 3.0-liter V6 twin-turbo engine weighs 194.8kg (429.5 lb) 14.1kg (39.1 lb) less than the engine it replaces. The new turbocharger and advanced intercooler (or CAC) system componentry adds just an extra 25.8kg (56.9 lb), for 220.6kg (486.3 lb) in total.
Infiniti states that it has also adopted a series of ‘innovation technologies’ for application in the new V6 to deliver a more engaging driving experience. Chief among these is the use of a new direct-injection gasoline (DIG) fuelling system. The high-pressure DIG system allows for more precise injection of fuel into the combustion chamber, delivering the exact amount required for smooth engine acceleration, depending on throttle position and engine speed.
A new cylinder-bore coating process allows the pistons to move more freely in the cylinders by reducing mechanical friction by a claimed 40% in comparison to the previous V6 engines. This mirror bore coating process involves cylinder walls getting treated with a thermal arc spray coating after which the coating is hardened. The ‘mirror-smooth’ cylinder wall reduces piston friction and boosts performance.
The mirror bore coating process saves the 3.0-liter V6 twin-turbo engine 1.7kg (3.8 lb) in weight, when compared to previous V6 engines, owing to the hardened tolerance that the spray system gives to lighter metals.
One of the most significant features in the all-new 3.0-liter V6 twin-turbo engine is the adoption of a new integrated exhaust manifold, built into the cylinder head, enabling the catalytic converter to be placed closer to the exhaust point. This results in a shorter flow path for the hot exhaust gases, allowing the catalytic converter to heat up twice as fast as its predecessor, further reducing emissions from a cold start.
By integrating the unit closer to the engine, Infiniti has been able to reduce the weight of the system by over 5kg.
March 9, 2016
