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Infiniti Q50 steer-by-wire system took 10 years to develop [w/video]

Infiniti's Direct Adaptive Steering (DAS) is quite a novelty - the system employs no physical connection between the steering wheel and the front wheels under normal circumstances and instead relies on a computer, clutch and steering-angle actuator to guide vehicles down the road with input from the driver.
In our First Drive review of a 2014 Infiniti Q50 equipped with the system, we weren't overly impressed by the artificial feedback. But we can't help but be impressed with how long Infiniti spent on its development: a full 10 years, according to Autoline Daily in the video report below. A staggering 70 percent of the research and development time spent on DAS was devoted to getting the steering feel right, and unfortunately, our first impression suggests their results still leave something to be desired, as we found it lacked the sporty feeling a sport sedan should have.
The weight of DAS is comparable to that of a conventional steering system due to its complexity. For example, three ECUs are used in the first-generation DAS system to ensure there's never a loss of steering, but Infiniti is refining the technology and is working to simplify it to reduce weight. One day Infiniti hopes that only one ECU will be needed to control DAS. We just hope it doesn't take the Japanese automaker another ten years to get the steering feel right.

Infiniti extends long-wheelbase Q50 L for the Chinese market

Want to sell your luxury sedan in China? You're going to need a long-wheelbase model. Not because the still-dominant Chinese government mandates it, or because the customers are taller, but because Chinese buyers tend to like being chauffeured around in the back of their luxury sedans instead of driving themselves, so the priority is on rear-seat space over driving dynamics.
We've seen the likes of Audi, BMW, Cadillac, Mercedes-Benz and Volvo all roll out long-wheelbase versions of their compact and midsize sedans specifically to cater to Chinese tastes. Even Infiniti - which now bases itself in Hong Kong - offers a long-wheelbase Q70 L not only in China but around the world, and has now bolstered its extended offerings with the reveal of the Q50 L, set to debut at the Chengdu Motor Show later this month.
Set to be produced locally for the local market, the Q50 L adds nearly two inches to the wheelbase of the Q50 to the benefit of rear-seat legroom. Power comes from Infiniti's 2.0-liter turbo four offering 208 horsepower and 236 pound-feet of torque, driving to the rear wheels through a seven-speed automatic transmission with drive-by-wire steering.

Infiniti's new VC-T changes the rules of small turbocharged engines

The upcoming Infiniti QX50 crossover does not get our pulse racing, no matter how shapely the QX Sport Inspiration concept that previews it may be. No midsize SUV does, to be fair. But it has something special under the hood – the world's first production variable-compression-ratio engine. That means the QX50's 2.0-liter turbo four, which makes 268 horsepower and 288 pound-feet of torque, will have up to 27 percent better fuel economy. Here's how it works. The trend of moving to smaller, turbocharged engines carries with it one big falsehood. Under low load when the turbo isn't needed, these engines are less efficient than an equivalent engine without a turbo because of the low compression ratio the turbo requires. That is, if you never need the extra power, you're wasting fuel. Turbocharged (and supercharged) engines use a lower compression ratio to prevent detonation. When you force extra air in a cylinder and mix it with fuel, it's more likely to prematurely go boom. Lowering the compression ratio prevents this problem, but it's less efficient. Infiniti's VC-T promises the best of both worlds, with a compression ratio that ranges from 8.0:1 for high-power turbo needs to a 14.0:1 ratio for fuel-sipping efficiency. At its heart the VC-T engine is a simple idea, but it's complicated to explain. Consider yourself warned. The photo below from Infiniti serves as a good visual overview. For the truly nerdy, this patent application covers the mechanical concept. Instead of having the pistons connected to the crankshaft, Infiniti's engine has a pivot arm with a connection on each end. One end connects to the piston, the other connects to a second lower shaft, which is controlled by an actuator arm. At any given time the engine's pistons move up and down according to the lobes on the crankshaft. But the actuator arm can change the angle of the pivot arm up and down. That is, the pistons still move in the same motion with the same stroke, but phase the entire stroke up or down. Move the pivot up and there's less room at the top, which means a higher compression ratio. Move the pivot down and the compression ratio goes down, too. As an added bonus, the lower shaft eliminates the need for counter-rotating balance shafts. Infiniti says this system works constantly and can vary the compression ratio to any number between 8:1 and 14:1. It also uses electronic variable valve timing on the intake valves to switch into Atkinson-cycle combustion for greater efficiency.