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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.

2014 Nissan GT-R Track Edition loses rear seats, gains performance

Nissan is adding yet another tier to the GT-R hierarchy for 2014 with the GT-R Track Edition. Debuting at the 2013 Chicago Auto Show, the bruiser ditches its back seat in the quest for a lower curb weight, and a set of more seriously bolstered front buckets keep occupants planted once the going gets twisty. The Nürburgring-developed Track Edition offers an integrated carbon fiber front splitter with brake cooling ducts as well as an even harder-core suspension. Engineers swapped the stock bits for special Bilstein DampTronic shocks and paired them with more aggressive springs.
The engine still delivers 545 horsepower and 463 pound-feet of torque and still relies on the split-second quickness of the standard GT-R's six-speed dual-clutch transmission. Expect to see just 150 examples of the 2014 Nissan GT-R Track Edition land on American shores starting this May. In the interim, check out the full press release below for more information.

A realistic approach to fixing Mitsubishi

There are going to be a lot of words written about what Nissan needs to do with Mitsubishi in the coming months and years in the interest of turning the brand around. After Nissan's purchase of a controlling stake in the diamond star brand, there's been more interest in Mitsubishi thanks to the potential of platform sharing and plenty of cash from Nissan-Renault to get the juices flowing again. But, while some have been doing their best to advocate for the return of the 3000GT, Evolution, and even the Starion - Many of these posts forget the reality of the market we live in today. As much as we like to look back fondly at the sports coupes of the '90s, a byproduct of the insane cash flows all the Japanese manufacturers had at the time, the reality of today puts a much greater emphasis on what is most-boring; Crossover SUVs, alongside mid-size and compact sedans. We do need to ask a fundamental question, how much Mitsubishi is enough to be able to continue to call the cars Mitsubishis? Aside from slight product revisions and reconfigurations, Mitsubishi (at least in North America) has been largely dependent on the same GS platform and 4B1 engines that date back to their long-time partnership with Chrysler (and Hyundai) in the mid '00s. Admittedly, the chassis and engines have served the company well, underpinning a wide variety of vehicles sold around the world, and seeing quite a few revisions to at least attempt to keep products competitive. But, the GS chassis is old, heavy, and severely out of date - and when matched to the underpowered 4B1 series engines - make for largely uncompetitive offerings in the market. While something like the Outlander Sport is indeed interesting compared to a Honda CR-V, it is by no means the smart choice in the segment. So, going forward, unless Mitsubishi has had a skunkworks of sorts developing their chassis and engine replacements over the past few years, what exactly are they planning to do for their bread-and-butter models? I think the straightforward answer is without a doubt the Nissan North America parts bin. With so many of their models selling well, and for the most part, are reasonably well-reviewed, it would be quite simple to adapt the chassis and powertrain to Mitsubishi's liking to create a high-volume alternative to what is currently available now.