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GM patent reveals new two-stage turbocharger

Modern turbochargers may be some of the best ever made, but performance is something that engineers are always trying to improve. According to GM Inside News, General Motors (GM) is hoping to alleviate some of the negative aspects of a two-stage turbocharger setup with a newly-patented design. The patent, that was filed on May 19, 2016, reveals a clever bypass system that allows the engine, a four-cylinder unit, to optimize both the low-pressure and high-pressure inlets for its respective functions. According to the filing, a conventional two-stage turbocharger setup is engineered to allow both turbines to operate simultaneously at low and mid engine speeds. At high engine speeds, only the low-pressure turbine works. The setup can't isolate either the low or high pressure side, which can impair low-end performance. GM's new two-stage turbocharger setup looks to eliminate this by linking the high-pressure turbo to the exhaust manifold through the high-pressure inlet duct. The low-pressure turbo is attached to the high-pressure turbo by a low-pressure inlet duct, which is linked to a connecting channel. A single actuator that is housed in the exhaust manifold creates a bypass that can opens the high-pressure inlet or close the connecting channel. Depending on what the engine load and speed is, the ECU guides the actuator—a single rotating spindle with discs corresponding to flanges on the high and low pressure sides—to isolate one of the two turbos. Isolating the turbos allow the respective inlets to be engineered for the best possible fluid dynamic performance. The setup should increase performance and decrease lag. There's no word on what car this setup will make an appearance on, but it will most likely be used in premium vehicles before trickling down to the rest of GM's vehicles. Related Video: News Source: GM Inside News, AutoGuide via GM Authority Cadillac Chevrolet GM Technology Sedan turbo patent engine turbocharging

Weekly Recap: Autonomous driving goes commercial in Nevada

Nevada granted Daimler Trucks North America the first license to run an autonomous commercial vehicle on public roads in the United States Tuesday, marking another milestone in the technology's rapid advancement. Gov. Brian Sandoval and Daimler truck chief Wolfgang Bernhard promptly used the license to lap Highway 15 near Las Vegas in a newly revealed Freightliner Inspiration Truck. It was a clear signal that autonomous driving is big-rig reality, though it's still a long way from widespread use. Nevada certified two of Daimler's Freightliner Inspiration Trucks, which use the company's Highway Pilot system with a stereo camera, radar, and lane-keeping collision-prevention features to regulate the brakes and steering. The radar component has a long-range sensor that can cover 820 feet at an 18-degree angle and a shorter-range unit that stretches 230 feet at a 130-degree angle. The Inspiration trucks are based on the existing Freightliner Cascadia Evolution model used on US roads. In addition to the autonomous technologies, it also has futuristic design cues, including blue lighting in the front and a new hood and grille. While there are only two Freightliner Inspiration trucks in existence, Daimler expects to bring the Highway Pilot system into mass-produced big rigs by 2025, in time to capitalize on the market's predicted growth. The German truckmaker predicts the global hauling market will triple by 2050, and the United States will be a key part of that growth. Trucks carry 69.1 percent the nation's domestic freight tonnage and hauled 9.7 billion tons of freight in 2013, according to the American Trucking Association. Daimler expects autonomous driving to augment this growth, and perhaps evolve the role of the truck driver. Still, the company points out autonomous tech is not meant to replace drivers, but to assist them and relieve fatigue and monotony on long hauls. The driver has to stay in control for passing, in city traffic, and when hooking up the trailer. The company said autonomous driving also offers the potential for improved fuel economy – tests showed a five-percent gain – and lower maintenance costs. Daimler also said the technology could reduce congestion on the road. Much of this is attributable to the constant flow of traffic, which is aided by autonomous driving. While the benefits are becoming increasingly apparent, autonomous technology is still met with skepticism.

What if the mid-engine Corvette is really a Cadillac?

Call me crazy, but I'm not convinced the mid-engine Corvette is the next Corvette. The rumor is strong, yes. And, contrary to some of the comments on our site, Car and Driver - leader of the mid-engine Corvette speculation brigade - has a pretty good record predicting future models. But it's another comment that got me thinking: or maybe it's a Cadillac. There is clearly something mid-engine going on at GM, and I think it makes sense for the car to be a Cadillac. First off, check out how sweet the 2002 Cadillac Cien concept car still looks in the photo above. Second, there are too many holes in the mid-engine Corvette theory. There are too many holes in the mid-engine Corvette theory. The C7 is relatively young in Corvette years, starting production almost three years ago as a 2014 model. Showing a 2019 model at the 2018 North American International Auto Show would kill sales of a strong-selling car before its time. Not to mention it would only mean a short run for the Grand Sport, which was the best-selling version of the previous generation. More stuff doesn't add up. Mid-engine cars are, in general, more expensive. Moving the Vette upmarket leaves a void that the Camaro does not fill. There's not much overlap between Camaro and Corvette customers. Corvette owners are older and enjoy features like a big trunk that holds golf clubs. Mid-engine means less trunk space and alienating a happy, loyal buyer. Also, more than 60 years of history. The Corvette is an icon along the likes of the Porsche 911 and Ford Mustang. I'm not sure the car-buying public wants a Corvette that abandons all previous conventions. And big changes bring uncertainty - I don't think GM would make such a risky bet. Chevrolet could build a mid-engine ZR1, you might say, and keep the other Corvettes front-engine. Yes they could, and it would cost a ton of money. And they still need to fund development of that front-engine car. I highly doubt the corporate accountants would go for that. But a Cadillac? Totally. Cadillac is in the middle of a brand repositioning. GM is throwing money at this effort. A mid-engine halo car is the just the splash the brand needs to shake off the ghosts of Fleetwoods past. And it's already in Cadillac President Johan De Nysschen's playbook. He was in charge of Audi's North America arm when the R8 came out. A Caddy sports car priced above $100,000 isn't that unreasonable when you can already price a CTS-V in that range.