1995 Cadillac Deville 4door 4.9l Brown on 2040-cars

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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 under fire from safety advocates over braking problem caused by recall fix

Safety experts are lambasting General Motors over what they say is the automaker’s slow notification of owners of certain 2019 sedans and trucks that a recall fix could cause power braking to fail and increase the risk of a crash, the Detroit Free Press reports.  GMÂ’s original recall in December targeted about 550,000 Cadillac CT6 sedans and Chevrolet Silverado 1500 and GMC Sierra 1500 pickups, all from the 2019 model year, over potentially defective electronic stability control and antilock brakes. In that case, GM said the errors would not show up as a diagnostic warning on the instrument cluster. But after GM had done recall work on 162,000 vehicles, about 1,700 owner have complained that their power brakes didnÂ’t work after they had the recall done and then used the OnStar app to start their vehicle. GM then issued a supplemental fix for customers whoÂ’d already had their vehicles serviced. In this case, a diagnostic warning should illuminate saying either “Service Brake Assist” or “Service ECS,” which GM says is a signal that a customer should not drive the vehicle and instead call their dealer, which will tow the vehicle and have it repaired. Safety advocates say the automaker hasnÂ’t gone far enough to protect customers. “The fact that you could potentially start a vehicle and not have brakes is a pretty risky proposition,” Sean Kane, president of the Safety Research and Strategies, which works on auto issues for plaintiffs and governmental organizations, told the Freep. “The fact that they wouldnÂ’t notify owners (sooner) is pretty stunning.” GM told the Freep it was required to notify the National Highway Traffic Safety Administration and file paperwork before it notified customers about the original recall, which was made Dec. 12. It then had to investigate and resolve the problem created by its original recall fix before alerting customers. GMÂ’s call center and dealers are contacting the remaining 900 customers who havenÂ’t yet had the update made to the original recall repair. GM also hired a vendor to send recall letters to the 550,000 customers affected by the original recall notifying them about the update. There are no known injuries or deaths related to the problem. Read the Freep story here.

Cadillac abandons plans for six-digit flagship sedan

So much for that party. Cadillac has announced that it is walking away from plans to build a high-dollar, rear-wheel-drive ultraluxury sedan. The low-volume model would have been based on the lusty Ciel Concept, and the production iteration would have carried a price tag well over $100,000. Executives with the automaker reportedly claim the model wouldn't have bolstered the brand enough to be worth the investment.
Even so, Automotive News reports Cadillac is still on track to build a range-topping four-door to go head-to-head with the BMW 7 Series and Mercedes-Benz S-Class. That model will likely be constructed on the company's upcoming Omega rear-wheel-drive platform, but we won't see it bow until at least 2016. Right now, the front-wheel-drive XTS sits at the top of the Cadillac lineup, and while that machine and it's twin-turbocharged V6 variant makes a compelling argument against certain luxury entries, it falls short serving as a legitimate competitor for the likes of the 7 Series and S-Class for enthusiast drivers.