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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 recalling 250,000 SUVs over door electronics

After a door-fire investigation that dates back to February, the National Highway Traffic Safety Administration has officially announced a recall today that affects around 250,000 General Motors SUVs for a faulty driver's door module. The recall applies to the Buick Rainier, Chevrolet Trailblazer, GMC Envoy, Isuzu Ascender and Saab 9-7X from the 2006 and 2007 model years, as well as the 2006 Chevrolet Trailblazer EXT and GMC Envoy XL for vehicles sold and/or registered in the Snow Belt.
Road salt use in these midwestern and northern states can lead to corrosion of the driver's door module on these GMT360 and GMT370 vehicles, which allows water to come in contact with the circuit board. If shorted out, the vehicle's power door locks and power windows will not work, and could possibly lead to overheating and, in some circumstances, a fire. No official word on how many total vehicles caught on fire, but back in June, 28 fires had been reported to the government agency. A fix for the problem is still being worked out, but all affected vehicle owners will be notified by GM.
Scroll down for the official NHTSA statement.

GM profits threatened by glut of pickups

Automotive News reports that General Motors may slash production or ramp up discounts in order to deal with an oversupply of pickup trucks. GM currently has more than double the standard supply of pickups, and the vehicles are threatening to dampen the automaker's profits for 2013. Typically, automakers try to sustain a 60- to 75-day supply of vehicles, but GM is currently loaded with a 139-day supply, as of last month. At the end of November, the automaker was sitting on 245,853 units.
The manufacturer says that it will adjust production accordingly before laying any incentives on the profitable pickups. Even so, there's some concern that the inventory swell could hurt the roll-out of the next-generation Chevrolet Silverado and GMC Sierra. GM actually began slowly stepping back production in August, but it's clear the company will take further action as it heads toward the end of the year and into the next. Analysts predict the automaker could reduce pickup manufacturing by nearly half in the first quarter of 2013.
That still may not be enough to keep GM from laying extra cash on the Silverado and GMC Sierra. While the company's incentive spending was down in November compared to the same month in 2011, both the Ram 1500 and Ford F-150 saw double-digit percentage increases in sales last month while the Silverado and Sierra numbers slid compared to a year prior. Incentive spending could help move more trucks and add some balance to the GM inventory surge.