VQ35HR•VQ25HR Engine Technology Overview V6 GASOLINE ENGINE Advanced technology takes the next generation of Nissan’s world-renowned VQ engine to new pinnacles of high-rev performance and environmental friendliness. Nissan’s latest six-cylinder V-type Major technologies engine inherits the high-performance DNA that has made Nissan’s VQ Taking the award-winning VQ series another step series famous. Taking the acclaimed toward the ultimate powertrain, Nissan’s next- VQ engine’s “smooth transition” generation VQ35HR & VQ25HR are thoroughly concept to higher revolutions than reengineered to boost the rev limit and deliver greater ever, this VQ is a powerful and agile power, while achieving exceptional fuel economy and new powerplant for Nissan’s front- clean emissions. engine, rear-wheel-drive vehicles. Higher revolution limit By greatly reducing friction, Nissan engineers achieved a smooth transition to the high-rev limit, New VQ Engine which has been boosted to a 7,500rpm redline. Advantages Lengthened connecting rods Smooth transition up to high-rev redline Lengthening the connecting rods by 7.6mm reduces Lengthened connecting rods, addition of a ladder piston sideforce on the cylinder walls. This reduces frame and other improvements greatly reduce friction for smoother piston action to support high- friction. The result is effortless throttle response rev performance. all the way to the 7500-rpm redline. New ladder frame Top level power performance in class The lower cylinder block that supports the crankshaft Improved intake and exhaust systems, raised uses a ladder-frame structure for increased stiffness. combustion efficiency, and other enhancements This suppresses vibration to minimize friction at high achieve class-leading power. Fuel efficiency and engine rpm. emissions are also exceptional. Higher power performance Thrilling acceleration sound Power boosting technologies include a symmetrical A symmetrical intake and exhaust system helps twin intake system and continuously variable valve produce a linear and clear throttle sound in timing control systems. response to engine rpm. Better fuel efficiency & cleaner emissions The world’s first use of hydrogen-free, diamond-like carbon (DLC) coated valve lifters and other friction- contents reducing measures help raise fuel efficiency by about Higher revolution limit 4 10% and attain a class-leading emissions rating. Top-level power performance in class 6 Thrilling throttle sound Thrilling acceleration sound 8 The symmetrical intake and exhaust system Better fuel efficiency & cleaner emissions 10 configuration helps generate a stable, linear and clear sound signature for the new VQ. 2 VQ35HR•VQ25HR Engine Technology Overview Advanced technology takes the next generation of Nissan’s world-renowned VQ engine to New heights of VQ performance new pinnacles of high-rev performance Since its 1994 debut, Nissan’s VQ engine series has continued to and environmental friendliness. evolve, based on its original engineering goals of simplicity, light weight, low friction and responsive power. The VQ’s exceptional performance has put it on Ward’s 10 Best Engines list every year since the list’s inception in 1995. The Nissan VQ is the only engine to hold this record. The latest VQ in this distinguished lineage has been redesigned with new dimensions and higher rigidity, yet weight remains about the same in the 3.5-liter VQ and has actually been reduced by about 8kg in the 2.5-liter VQ, while lowering the center of gravity. The result is an even more impressive VQ powerplant. New VQ35HR VQ35DE Output New VQ35HR engine 5000 6000 7000 8000 Engine speed (rpm) New VQ25HR engine 3 Higher revolution limit By reducing friction in all the engine’s moving parts and increasing the stiffness of the crankshaft and its ancillary components, Nissan engineers achieved smooth and effortless transition throughout the powerband. Lengthened connecting rods (VQ35HR only) To support higher engine speeds, Nissan applied a friction-reducing solution used in racing car VQ35DE New VQ35HR engines: lengthening the connecting rods. Raising the cylinder block deck height permits a 7.6mm increase in connecting rod length. This reduces piston inclination and the resulting sideforce exerted against the cylinder wall, thereby reducing friction particularly at high speed. The result is Side effortless acceleration with a smooth powerband force Side extending up to the 7,500rpm redline. force Friction is reduced with the higher block deck and longer connecting rods Raised block deck height and longer connecting rods New ladder frame (VQ35HR only) At high rpm, crankshaft deformation leads to increased vibrations. As a countermeasure, the VQ35DE New VQ35HR VQ35HR engine employs a stiff ladder frame to support the crankshaft. This enhances the rigidity of the engine as a whole, thereby greatly reducing vibrations at the high rpm rates for which the engine is designed. Cylinder block vibration analysis Vibration Small Large Ladder frame effectively suppresses vibrations Ladder frame 4 VQ35HR•VQ25HR Engine Technology Overview Increased crankshaft stiffness During high-rev operation, the crankshaft may fl ex and twist, causing noise, vibration and, potentially, Pin diameter 52mm increased to 54mm (VQ35HR) damage to the journals. To deal with this issue, the 45mm increased to 50mm (VQ25HR) new VQ engine uses a larger journal diameter and a stiffer crankshaft. This minimizes vibrations at higher revs. In the VQ35HR, the connecting rod bolt diameter has also been increased from 8mm to 9mm to gain about 25% in strength. These measures help achieve the connecting rod and crankshaft durability required in a high-speed engine. Journal diameter 60mm increased to 65mm (VQ35HR) Crankshaft Friction is reduced with the higher block deck and longer connecting rods 8mm increased to 9mm Stronger connecting rod bolt (VQ35HR engine) Asymmetric piston skirt Pistons are normally designed with a “skirt” to prevent rocking within the cylinder. The new VQ engine uses asymmetrical piston skirts to reduce friction. A smaller skirt area is used for the part of the piston receiving less sideforce during reciprocal piston motion. This reduces friction by about 7.6%, thereby contributing to smoother revving performance. Large skirt on Small skirt on high-pressure (thrust) side low-pressure side Asymmetric piston skirt 5 Top level power performance in class A symmetrical twin intake system and Continuously Variable valve Timing Control (CVTC) help the new VQ achieve class-leading output. Symmetrical twin intake system To reduce air intake resistance, the new VQ engine adopts a symmetrical twin intake confi guration. Compared to the usual single intake, this enhances the engine’s breathing for more effi cient air distribution. Because it does not require enlargement of the duct diameter, this approach helps save space, thereby offering more leeway in engine compartment layout. Symmetrical twin intake system Straight intake port (VQ35HR only) To support high-rev, high-power engine performance, the new VQ adopts a straight intake port design. This confi guration signifi cantly improves intake effi ciency by providing air to the engine in the quantity required during high-speed, high-load engine operation. Straight intake port 6 VQ35HR•VQ25HR Engine Technology Overview CVTC The VQ engine adopts a valve control system that optimizes both intake and exhaust side CVTC for intake valves timing according to engine rpm. Employing hydraulically actuated Continuously Variable valve Timing Control (CVTC) for the intake cams and electromagnetic Valve Timing Control (e-VTC) on the exhaust side, the system enables high fl exibility in valve timing operation. The result is improved combustion effi ciency throughout the powerband. e-VTC for exhaust valves Continuously Variable valve Timing Control (CVTC) system Optimized valve diameter (VQ35HR only) Although it would seem a larger valve diameter would improve airfl ow, it can actually increase VQ35DE engine New VQ35HR engine airfl ow resistance, particularly when it is partially open and there is an interfering fl ow through an adjacent valve. In the VQ35HR, valve diameter is optimized to minimize intake resistance and improve breathing effi ciency throughout the operational Constricted Large Free fl ow Small cycle from low to high valve lift conditions. diameter diameter Intake valve diameter decreased from 37.0mm to 36.6mm. Exhaust valve diameter decreased from 31.2mm to 30.2mm Result: Improved fl ow at low lift Optimized valve diameter Raised compression ratio (VQ35HR only) The new VQ engine uses a higher compression ratio to raise thermal effi ciency and achieve greater power output. This also contributes to improved fuel economy. At the same time, refi nements in VQ35DE engine the exhaust system effectively minimize NOx to compensate for increased generation due to the higher compression ratio. New VQ35HR engine Redesigned combustion chamber permits higher compression ratio 7 Thrilling acceleration sound Drivers enjoy a clearer, more thrilling throttle sound, thanks to the symmetrical intake and exhaust system. Symmetrical intake and exhaust system The VQ engine uses a symmetrical intake and exhaust system to help produce clear and powerful Engine speed (rpm) Volume sounds that rise along with engine speed as Large the throttle is opened. The area where the left and right sides of the exhaust system merge is designed so that the two fl ows do not mix, thereby suppressing generation of 0.5 subharmonics*1. Muddy sounding components are also