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It's been a long time since I've posted new items, and if it's a repost, well it probably won't be the last time...

New VQ engines for upcoming Skylines.

The current VQ series engines have been reviewed and updated in time for the upcoming launch this northern Autumn. The names 'VQ35HR' and 'VQ25HR' mean High Revolution/High Response due to the refined and revable nature of the new engines. A max rev ceiling of 7,500rpm for the HR series engines should put to rest the complaints some had about the previous generation VQ, aswell as greater power and a sweeter engine note.

With the new engine development, it started with the update of each main part based on the current VQ. 80% of the engine has been changed, and the remaining 20% are parts not related to engine performance such as the bolt/nuts and seals etc. The V6 configuration is the same as is the bore and stroke, hence keeping the 'VQ' designation.

Power wasn't the only thing that was pursued but also the sound, Nissan wanted a pleasant acceleration soundtrack to compliment the superior refinement offered by the V6. Alot of testing was done to eliminate unwanted noise while efforts were made to improve the 'sports note' of the engine by means of exhaust optimization of the twin mufflers, the tuned length exhaust manifolds and also the exhaust catalysts etc.

As for the engine induction, a symmetric twin throttle body induction system and straight suction ports are adopted to obtain class-leading maximum power, and intake resistance has been decreased by 18%. In addition, CVTC (Continuously Variable valve Timing Control) is installed controlling the camshafts, the setting of the valve timing with a high degree of adjustability is possible, and the combustion efficiency of the whole intake system has been improved from low in the rev range to high. On the exhaust side is an electromagnetic type CVTC, and on the induction side is an oil pressure type. The overall improvement in torque through the rev range is welcomed by use of CVTC, though the main reason CVTC is installed on the exhaust side is to control EGR (self-EGR). The engine block was not only refined for vibration and harshness, but also improvements in oil circulation (enlarged sump) and cooling.

In a big step to decrease friction, the Conrods are lengthened giving a reduced angle of upwards/downwards force in relation to the piston so that piston friction is reduced along the cylinder wall during full crank rotation, therefore the height of the deck of the cylinder head has had been increased. As well as reducing friction for the main movement parts, the piston rings and crank surfaces also were given attention. Also in a world first for use on a domestic engine, the valve lifters are coated in a 'diamond like carbon coating' so that friction decreased by 40%.

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actually, re-engineering a motor after 3 years sounds to me like an admission that it was under-engineered and developed in the first place :rolleyes:

Good to hear that the engineers have had a win over the renault accountants.

Doesn't mention if its a direct injection engine or not?

Nothing in that article I translated mentioned direct injection which went into a bit of detail regarding the new features, so I guess the HR engines don't have it... although the previous VQ25DD and 30DD engines did.

actually, re-engineering a motor after 3 years sounds to me like an admission that it was under-engineered and developed in the first place :)

How many revisions did the various RB versions get over its 15+ year life?

The VQ35DE has been around for quite some time, and appeared in Wards' list of Top 10 Engines of the Year (in its class) for the past decade. Its just not ever been put into a sports car before.

I'd agree that it wasn't engineered for a sports car application in the first place (too much low end, not enough top end, and weak internals) but the fact that they're revising it doesn't indicate an inherent problem with the VQ design.

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