1968 Chevrolet Caprice 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

MotorWeek looks back at 1995 Chevy Tahoe, GMC Yukon

MotorWeek's Retro Review series gives us a nostalgic look back at some of the best sports cars and luxury sedans available in the 1980s and '90s. For its latest clip, the show shifts gears to remember the 1995 Chevrolet Tahoe and GMC Yukon. Similar to the success of crossovers today, SUVs were tallying big sales and making big money for automakers in the mid-'90s. The Tahoe and Yukon filled slots in the market as steps down from the larger Suburban. These twins weren't wanting for space, though, with plenty of room to haul around a family. MotorWeek came away generally impressed too, and called the models some "of the better riding sport utilities we've ever experienced." This review comes with some jazzy, electric guitar licks to enjoy in the background.

GM recalls trucks and SUVs for brake pedal problem

The Basics: General Motors will recall over 473,000 North American examples of the 2015-2016 Chevrolet Silverado HD, GMC Sierra HD, and police pursuit versions of the Chevy Tahoe. These include 426,573 vehicles in the US and 46,837 in Canada, according to Reuters. The Problem: The brake pivot nut can loosen over time, which can render the pedal inoperative. This would be a danger to drivers trying to stop the vehicles. In some cases, the "Service Engine Soon" light might come on. Injuries/Deaths: None reported. The Fix: Dealers will inspect the pivot bolt, and if necessary they will apply adhesive to it and reinstall the part with increased torque. If You Own One: "We expect to start customer notifications shortly," GM spokesperson Tom Wilkinson told Autoblog. Related Video: Transport Canada Recall # 2016053 Recall Date 2016/02/04 Notification Type Safety Mfr System Brakes Manufacturer Recall Number 20760 Units Affected The number of vehicles or components affected by the recall. 46,837 Category Light Truck & Van, SUV Recall Details On certain Heavy Duty and Police Pursuit vehicles, the brake pedal pivot nut may become loose, causing the brake pedal to be loose or inoperative. If the brake pedal becomes loose or inoperative, it could interfere with the accelerator pedal, and/or the driver may be unable to safely stop the vehicle through application of the brake pedal, potentially affecting stopping distances and increasing the risk of a crash causing injury and/or damage to property. Correction: Dealers will inspect the pivot bolt installation to determine whether the vehicle has already received the production remedy. If not, the dealer will add adhesive to the nut, and reinstall the nut at an increased torque. Note: This condition may result in the "Service Engine Soon" light illuminating, and brake lights may stay on longer than expected. Make Model Model Year(s) Affected CHEVROLET SILVERADO 2015 2016 CHEVROLET TAHOE POLICE PURSUIT VEHICLE 2015 2016 GMC SIERRA 2015 2016