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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.

Infiniti Q50S getting G37's hydraulic steering for 2016

Sometimes, new technology doesn't make things better. Take the march of power steering technology as an example. Electrically assisted systems are in vogue at the moment for their ability to increase fuel efficiency, but tuning them to offer good feedback remains something of a dark art. Some automakers get it, but most don't. The previous hydraulically assisted setups just seem to be inherently more communicative when driven with enthusiasm. And it looks like Infiniti might be learning this lesson the hard way.
In talking with Keith St. Clair, the luxury brand's head of product planning, Car and Driver has learned that the Q50S is probably going to ditch its standard electrically assisted steering in favor of a hydraulic system derived from the old G37, a model soon to be renamed the Q40. The system should make the sedan more engaging behind the wheel, but it still won't help those who tick the option box for Infiniti's controversial Direct Adaptive Steering drive-by-wire system.
According to St. Clair, Infiniti's engineers have heard the complaints of critics and previous G37 owners about the Q50S model's electric steering system, and wanted to see what they could do. They didn't have to go far to figure it out - all it required was taking the steering rack off of a G37 and putting it onto the Q50S. After a little tweaking, "the car is a blast to drive," St. Clair reports. Now, the company is said to be fast-tracking the switch, and it could be ready for the 2016 model year.

Red Bull keeps 2015 RB11 F1 challenger under wraps [UPDATE]

UPDATE: A previous version of this post suggested that Daniil Kvyat drove for Red Bull last year, when he actually drove for its affiliate team Toro Rosso. The text below has been updated with the correct information. This season will be one of new beginnings for Red Bull Racing. It's the first time in three years that it's not returning to the Formula One grid as defending champions, and without a world champion at the helm. But return it will to fight to regain its title, and this is the car with which it intends to do so. Revealed ahead of the season's first test session in Jerez this weekend, the new RB11 is wearing a bold camouflage "testing livery" of the type we're more accustomed to seeing on road-going prototype than on a racing car. Expect it to be replaced by the familiar blue, red and yellow by the time the season kicks off in Melbourne next month. Though the camouflage may keep certain aero developments disguised (if not altogether hidden) from the prying eyes of its rivals, the sloping nose mandated by the new regulations is plain to see. Otherwise the new RB11 is likely more of an evolution rather than a revolutionary clean-sheet redesign over the RB10 that returning hot-shoe Daniel Ricciardo drove last year, to be joined this season by Daniil Kvyat, who's been promoted from Toro Rosso to replace departing four-time champion Sebastian Vettel. Whether they can succeed, however, will largely depend on the engine. Red Bull has emerged as the primary partner for engine supplier Renault (sister company to the team's title sponsor Infiniti). In fact, after Lotus switched to Mercedes (and assuming Caterham doesn't make it back to the grid), Red Bull and its sister team Toro Rosso will be the only teams running Renault engines this season. The team says it has worked closer than ever with the French automaker to develop the Renault power unit, but chances are slim that they'll be able to catch up to Mercedes given the restrictions on engine development. If anyone can catch the Silver Arrows, though, it'll surely be Red Bull – the only other team to win a grand prix last season. THE RB11 REVEALED After an intensely busy off-season, Infiniti Red Bull's Racing's 2015 Formula One car, the RB11, has hit the track and begun testing at the Circuito de Jerez in Spain ahead of the new season.