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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

GM finds steering flaw, decides it doesn't warrant a recall

Guess what? General Motors is back in the spotlight for not recalling something. This time, though, not only does the company have an argument against a recall campaign, but its position is supported by the National Highway Traffic Safety Administration. According to The New York Times, over 50 owners of GM vehicles have reported instances of stuck or seized steering after driving long distances without moving the wheel. One owner complained to NHTSA that the "locked" steering of their 2013 Buick Verano caused a collision with a concrete barrier in a construction zone. Along with the 2013 to 2014 model year Verano sedans, Chevrolet Cruze and Malibu sedans are also affected. Considering the popularity of those models, GM needs to have a reason for not issuing a recall, right? "Based on a very low rate of occurrence – ranging from less than one half to less than two incidents per thousand vehicles – and the fact that the condition is remedied when the wheel is turned, GM determined this was not a safety issue," spokesman Alan Adler told The Times. The company has, however, issued a technical service bulletin for owners that complain of the problem. The fix is nothing more than a software update that is covered for 10 years or 150,000 miles from new. NHTSA cited GM's actions, along with descriptions of the problems from customers, in its decision not to issue a recall, with spokeswoman Catherine Howden saying, "the symptoms described would be a brief, perceptible change in steering feel that has little to no effect on the driver's ability to safely steer the vehicle." "When terms like 'notchy,' 'stick,' 'slip' or 'feel' are used, it does not indicate a meaningful increase in steering effort," Howden told The Times via email. What do you think? Is GM in the wrong here? Should there be a recall, or is the issue so limited as to not warrant one? Have your say in Comments. Featured Gallery 2013 Buick Verano Turbo: Review View 20 Photos Related Gallery 2014 Chevrolet Malibu: First Drive View 36 Photos Related Gallery 2014 Chevrolet Cruze Turbo Diesel: Quick Spin View 14 Photos News Source: The New York TimesImage Credit: Copyright 2015 Steven J. Ewing, Seyth Miersma / AOL Government/Legal Recalls Buick Chevrolet GM Safety Sedan buick verano

2014 Chevrolet SS makes its live debut

Chevrolet showed off the new 2014 SS in an airport hangar last night, its first rear-wheel-drive performance sedan in the US since the Impala SS from 1997. We'll have more to say about the SS later today, but this is the sedan that Chevrolet sees as the final piece in restoring its performance credentials. For those of you looking for a manual transmission, however, that wish will go unfulfilled - at least for now: the only two options buyers will have are the color and whether or not they want a sunroof.
We'll work on getting some more angles (in better light) today at Daytona International Speedway, but with fans seeing the car for the first time, we don't hold out much luck of getting a clear shot. So for now, enjoy the high-res gallery above.