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Nissan 370Z Nismo freshening coming tomorrow

Nissan is set to bring a special to the Fairlady faithful at the annual ZDAYZ fest. Based on the sole teaser and the event it's being unveiled at, it's pretty clear that Nissan is going to be issuing some kind of update to the Nismo version of its 370Z.
What that update is, though, is unclear. We can see a few small visual tweaks, like the horizontal LED running lights and their associated vertical vent. The grille looks reformed as well. Beyond that, though, it looks like we're stuck waiting for the full details until tomorrow afternoon. Until then, take a look below for the world's shortest press release.

2015 24 Hours of Le Mans live race report

Check back regularly for more race updates every few hours. No, you don't need to stay up for the entire 24 Hours of Le Mans, but if you want to catch any of the action, Autoblog friend Reilly Brennan has a handy guide. And to keep you up to speed on the latest race events, we'll be posting live from Le Mans with regular race reports.Hour 1: Five laps in, Audi breaks up the three Porsches at the front, with the #19 919 Hybrid, driven by Nico Hulkenburg, passed by all three R18s. Hulkenburg eventually took back fifth position only to fall back again after the first pit stop. Meanwhile, clutch trouble kept the #23 Nissan GTR-LM in the pits until 15 minutes into the race. The other two Nissans were forced to start at the back of the grid after failing to the meet the 110 percent qualifying speed regulation. At the end of the first hour, just 7.5 seconds separated the first six cars. Then the factory team #92 Porsche GTE car caught fire, with the the #13 Rebellion P1 car taking frontal damage in the ensuing carnage. With the safety car out, the field is once again bunched up.Hour 2: The slugfest between Audi and Porsche continues, with neither side backing off. Halfway through the second hour the #7 R18 passes both leading Porsches for the top position. After another round of pits stops Porsche regains the lead until lap 30, when the Audi overtake once again and quickly pulls out a three-second gap. Nico Hulkenburg passes the other two Audis to join his Porsche teammates. At the beginning of the third hour it's Audi #7, Porsche #17, #18, and #19, followed by Audi #8 and #9. 33 seconds separates this group, with Toyota a minute back from the front car.Hour 3: On track the action refuses to stop. Although it's early, Audi is looking strong with the overall lead in the #7. What's more is that the Audis run four stints per set of tires, while the Porsche cars have to change rubber every third stop. But after a quick refueling, the lead R18 gets a tire puncture and comes back in 3 laps later, allowing Porsche to take over the top two spots. Then as the hour closes out a yellow flag causes traffic to bunch up and the #8 Audi gets stuck with nowhere to slow down. Driver Loic Duval dives for the side of the road but hits the guard rail and careens across the track, damaging the front and rear bodywork. The rest of the car is still intact, though, and once in the pits Audi replaces the entire front and rear of that in only three minutes.

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.