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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

How GM engineers are using diaper 'snow' to keep you warm

Testing how snow affects General Motors' vehicles isn't really a problem right now for the company's engineers, but in the dog days of summer the process isn't exactly easy. The only real option is for them to book time at the automaker's climatic wind tunnel. However, a flash of brilliance from an engineer allows snow to be simulated regardless of the temperature outside, and the discovery is all because of his daughter's wet diaper. The realization came to GM Thermal Systems engineer Nicholas Jahn while he was swimming with his daughter and noticed how her diaper ballooned in size in the water. He found out the substance that makes this possible is called sodium polyacrylate. When the material gets wet it grows and forms fluffy flakes that are a close imitation of snow. Best of all, the stuff can be prepared easily any time of the year, and it's reusable. The engineering team uses the material to test the effectiveness of the heating systems of GM's vehicles. They spread the sodium polyacrylate over the inlets at the base of the windshield to obstruct the airflow and then crank the heater. After some time, they can see how much is being sucked into the system and design more efficient systems in the future. See how the process works in the video above and read about the diaper discovery in GM's press release below. Diapers Change Chevy Cruze Winter Warm-up Time GM validation engineer uses diaper material "snow" to reduce frigid drives 2015-01-06 DETROIT – An item commonly found on an infant's changing table is helping General Motors' engineers simulate snow year round, ensuring heating systems in cars like the 2015 Chevrolet Cruze can quickly and efficiently warm its interior. Packed snow can prevent air from entering the inlet panel at the bottom of the windshield, obstructing the flow of air into the heating system and reducing the amount of air it can push out. This can lead to less efficient warming of the car's interior and windshield defrosting. "The last thing anyone wants to do when it's freezing cold out is scrape their windshield," said Nicholas Jahn, GM Vehicle Thermal Systems engineer. "The testing we perform on the Chevrolet Cruze with the diaper material allows us to maximize the car's heating capabilities." Ironically, Jahn stumbled upon his diaper-based testing method in the middle of summer. During a swim with his daughter, he noticed her diaper multiplied in size when it came into contact with water.

Chevy Spark EV could be coming to Midwest later this year

Ohio is not known as a hotbed of EV sales – if anything, the state is a bit anti-EV, thanks to a legislative fight against Tesla's direct sales model – but it might be on Chevrolet's short list to expand the market for the Spark EV in the near future. The latest official GM press release on the battery-powered Spark still says the car is "available exclusively in California and Oregon," but Hybrid Cars found four Ohio dealerships that list a Spark EV on their websites, with hints the the car will be coming to the Midwest state by the end of the summer. See, for example, here, here, here and here. But that's probably not going to happen, according to Randy Fox, GM communication's manager for passenger cars. Fox told AutoblogGreen that, "At this point in time, we don't have any official plans to expand the Spark EV beyond California and Oregon." The reason is that California and Oregon have the infrastructure to support EVs, Fox said, and GM wants to be able to support its EV customers. "We are continuing to look at other options," he said. "The selling point for electric cars today is not advertising, it's eyeballs, it's peer exposure" – John O'Dell John O'Dell, a senior editor at Edmunds.com, told AutoblogGreen that, "It makes sense for [GM] to expand sales and it makes sense to do it in a quiet manner, to get these vehicles on the road. The selling point for electric cars today is not advertising, it's eyeballs, it's peer exposure. If someone in my neighborhood has one and he likes it, then maybe I can trust him. So it's important to get these vehicles on the road." Chevy sold 182 Spark EVs last month, a significant increase over the 98 sold in April. That's still small potatoes compared to the 3,000+ Nissan Leaf EVs sold last month, but making the electric Spark available in Ohio, say, or GM's home state of Michigan could boost those numbers. AutoblogGreen called a few dealerships in Michigan to see what they had heard. One salesman said he didn't think GM had started production yet but the inventory manager for another dealership said the Spark EV is scheduled to arrive in the Midwest in "roughly the fourth quarter." What would GM's incentive be to offer the car in markets outside of California where it can gain ZEV credits with each sale?