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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 Acadia goes big again? Spy photos show next-gen prototype

GMC is testing what looks a lot like a new full-size SUV, signaling the likelihood that it will return to full-size segment after the current generation has run its course. GM downsized the Acadia for the 2017 redesign, carving nearly 10 inches off its length and 3 inches from its girth. For the next generation, it appears that script will be aggressively flipped.  The hierarchy of GM's unibody family SUVs was already a bit wonky before the Acadia's 2017 redesign, and continues to be now. While it would be logical for the Chevrolet Traverse, GMC Acadia, Buick Enclave and Cadillac XT6 — all three-row crossovers — to be different skins on the same fundamental chassis, that's not actually the case. The Acadia is a full foot shorter than either the Traverse or Enclave, with the XT6 falling in between. Based on these photos, that will no longer be the case when the new GMC Acadia debuts. Since the current one went on sale in 2016 as a 2017 model, it's about due for a replacement.  We can't see much beyond basic proportions here, but those tell a clear story. It's pretty obvious that the hood on the prototype is wider and sits higher than on the current car, with perhaps less slope to the now-wider nose. We can also see the faintest impressions of creasing on the flanks, likely leading to the same broad, angular hip treatment present on the current car. Viewed side-by-side, we can see a little more front and rear overhang. There's no obvious hint of substantially longer wheelbase here (the rear doors line up almost perfectly), so we're probably looking at something that is wider but not necessarily much longer.  In any event, we shouldn't have to wait too long to find out exactly what GM has in store for its "Pro" brand.  Related video: This content is hosted by a third party. To view it, please update your privacy preferences. Manage Settings.

2023 GMC Canyon debuts August 11

Chevrolet started GM's new-generation midsize truck party with the 2023 Colorado, now GMC's about to hit the stage with the 2023 Canyon. On August 11 at 11 a.m. Eastern time, we'll see what the new generation has done for the Colorado's upscale sibling. GMC teased us with a low angle of the coming Canyon in AT4X trim April. That revealed brawnier bits like big Goodyear Wrangler tires wrapped around 17-inch beadlock-capable wheels, plastic wheel arch flares, and rock rails. The initial version of that trim will be called the AT4X with Edition 1 Package, the front view showing split headlights, a new grille, thin LEDs, and a brush bar like the unit sprouting from nose of the Colorado ZR2 Desert Boss. We're also told there will be a "higher and wider stance, which is factory lifted." The current AT4 trim gets raised one inch, and we have a feeling the AT4X will get around three inches on its tippy toes just like the Colorado ZR2. The rationalization of body styles into a single Crew Cab Short Box will make ease configurations and production. Sadly, the 2.8-liter Duramax four-cylinder diesel is all but certain to be a goner here as well. The 2.7-liter four-cylinder gas engine should slip in here as the sole engine choice in two or three outputs. There's no telling which trims will get which outputs standard, but the choices are a base tune with 237 horsepower and 259 pound-feet of torque, a middle turbocharged tune with 310 hp and 390 lb-ft, and a high-output turboed topper with 310 hp and 430 lb-ft.   The 2023 GMC Canyon AT4X with Edition 1 Package will be available to order on the same day the lineup is revealed, at which time we expect to find out what's included in the Edition 1 versions compared to the AT4X variant that will join the lineup for series production. Related video: This content is hosted by a third party. To view it, please update your privacy preferences. Manage Settings.