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'Killing a Duramax' Gale Banks YouTube series methodically tunes a diesel to death

Learning or perfecting a skill by watching YouTube videos is known as attending YouTube University. GM Authority picked up on one of the video site's more fascinating courses, hosted by Gale Banks; in a fair world, he should be referred to as Professor Banks when it comes to diesel engines and truck tuning. A few months after GM introduced the updated L5P 6.6-liter Duramax diesel V8 in the 2020 Chevrolet Silverado HD and GMC Sierra HD that ships with 454 horsepower and 910 pound-feet of torque, Banks decided he wanted to methodically tune the engine to death. The purpose of the resulting series, called "Killing a Duramax," is to push more power out of the engine in order to discover which parts break and when — or, as Banks puts it, force-feed the Duramax "until the crank hits the street and the heads hit the hood." With that knowledge, Banks can figure out all the weak points on his way to building what he calls a "Superturbo," that being a supercharged, twin-turbo race engine with more than 1,000 hp. What makes the series fascinating is Banks' knowledge, paired with the company's comprehensive iDash engine monitoring system that keeps tabs on a glut of parameters every step of the way. So for instance, you get Banks explaining the differences between inches of mercury and barometric pressure, how those are different from the water content of the air measured in grains, then showing those readouts on the iDash, then explaining in detail how they affect the air density in the Duramax system. The stock Borg-Warner variable turbo gets a lot of airtime — Banks accuses it of being "out to lunch" because he feels it's the weakest link on the engine. That turns into a turbo teardown and a deep explanation of performance pitfalls, such as when air pressure on the turbine begins to diverge from the boost pressure coming from the compressor. Banks says he can keep close tabs on where power's coming from, because the iDash monitors the horsepower contribution provided by the ambient air, the turbo, and the intercooler separately. The major changes so far are a stouter Precision 7675 turbo and TurboSmart wastegate (episode 5), a twin intake (episode 6), a custom liquid-cooled intercooler from a marine engine, a new GM oil cooler and synthetic oil (episode 10), and new injectors (episode 11).

GMC shows how the 2022 Hummer could have looked even more futuristic

Excitement filled the room when GMC asked its designers to resurrect the Hummer in April 2019, but a tinge of uneasiness permeated the department after executives locked in an early 2020 unveiling date. Luckily, stylists knew what they wanted early on in the development phase, and preliminary design sketches give us a fascinating look at how they shaped the electric off-roader that ended up making its global debut online in October 2020. Hummer, the brand, unceremoniously shut down in 2010 after General Motors failed to sell it to the Chinese, but its design DNA was so strong that stylists were able to pick up where their predecessors left off. All of the sketches published on Instagram by the official General Motors Design account show a boxy truck with a tall front end, a short windshield, and a generous amount of ground clearance. These styling cues trace their roots to the AM General Humvee that entered production in 1984 and made its combat debut when the United States invaded Panama in 1989. Even the wildest drawings still depict a pickup that's immediately recognizable as a Hummer. Most of the early design sketches wear some variation of the seven-slot grille that characterized Hummer's production models; it's a styling cue that hints at a heritage shared with Jeep under the American Motors Corporation (AMC) umbrella. Oddly, none wear the round headlights seen on the H2, the H3, and the HX concept that nearly became the H4. Was GMC afraid that its Hummer would end up looking too much like a Jeep? And, at least one sketch shows a fold-down windshield, a feature that will not make it to the assembly line. Sketches never reach production without modifications made in the name of packaging and safety concerns, and the Hummer is no exception, but stylists did a good job of reinventing the brand's design language without copying or erasing the past. If the company had stuck around long enough to make a second- and a third-generation H2, odds are it would look a lot like the GMC-branded model that will enter production in a year. GMC remains on track to start 2022 Hummer deliveries in late 2021, though it told Green Car Reports that it still hasn't built a fully functional prototype yet. When it arrives, this outdoorsy pickup will land in a burgeoning segment of the truck market that numerous models (including the Rivian R1T and Ford's electric F-150) will also call home.

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.