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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 cutting vehicle trim options to save money for electrification

Information continues to filter out about GM's plans based on comments the automaker made during its Capital Markets Day event in February. GM President Mark Reuss said the company's push to save money by rationalizing the number of build combinations will continue in 2020, carrying on the work done in 2019. As GM Authority covers, last year, the carmaker cut 3,500 components across model lines, a 12% drop in the number of parts it needed to stock in its plants. Reuss used the next-generation Chevolet Equinox and GMC Terrain as examples for more cost efficiencies, saying build possibilities — which include international markets and their options — will be cut by more than 50%, and use more shared parts. "We will reduce total trim levels on Equinox and Terrain from eight to six," Reuss said, "reduce engine variants from 11 to 5, reduce build combinations from more than 200 to less than 100 per program, and see significant cost savings of an already paid-for architecture that took the mass out, helping us self-fund electrification programs." GM will plow a large amount of the money it saves into its ambitious EV program. In 2017, the automaker said it intends to have 20 electric vehicles on the market by the end of 2023, some of which could be shared between brands. An automotive analyst at Seeking Alpha and a piece in Automobile attempted to put specifics to what we should expect. As Automobile points out, the first two EVs in the 20-car program are already on sale, being the Ariv Meld and Ariv Merge eBikes available in Belgium and The Netherlands. We've seen the Cruise Origin autonomous rideshare taxi, although we don't know when it will hit the road. The next three, which we should see in the metal shortly, are two Cadillac EVs and the GMC Hummer EV pickup. The Cadillac pair are expected to be sized like the XT4 and XT5, and along with the Hummer, should hit the market starting in late 2021.

Race Recap: 2013 Twelve Hours of Sebring, cakewalk up front, grindfest out back [w/spoilers]

This year's 12 Hours of Sebring wasn't exactly a foregone conclusion because we're still talking about racing, and anything can happen when the speeds are as high as the adrenaline and the desire. But we're still talking about Audi bringing it's two top-spec racers - and its huge budget and its nearly neurotic attention to detail - to a race that it uses as a test bed for The 24 Hours of Le Mans and as a way to open the endurance racing season with a victory.
Besides, 12 hours is a long time, especially at Sebring, and things didn't go all Audi's way. On top of that, although it was a pretty quiet race, behind the Audis things got even grimier, with plenty of battles, plenty of mechanical issues, and the new BMW Z4 GTE and Viper GTS-R being race tested. Oh, and that brand new chromed-out DeltaWing...