1994 Gmc K1500 Suburban Sle Sport Utility 4-door 5.7l 4x4 on 2040-cars

Auto blog

'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 recalls 740,000 Terrains to address headlight issue

GM is recalling 740,581 of its 2010-2017 GMC Terrains to address an issue with their headlight lenses that allow intense beams of light to escape at certain angles. GM had petitioned the government for an exemption because the errant photons aren't being cast directly at oncoming drivers, but after a review, NHTSA denied the request, leaving the ball in GM's court. After taking time to "review NHTSA's decision and explore potential next steps," GM relented and announced a recall campaign.  The Terrain's headlight design allows a narrow sliver of low-beam light to reflect off the inner surface of the high beam reflector, GM's defect report says. The reflections depart the lens at angles that don't make them directly hazardous to oncoming drivers, which is why GM petitioned for an exemption. However GM says the bright spots can cause glare or just be inherently distracting, either of which can cause problems on the road. Per NHTSA, these slivers are four times brighter than allowed for low-beam headlights.  If you own a last-generation GMC Terrain, expect to start receiving notices about this recall in mid- to late April, however the company has not yet said exactly how the problem will be remedied. Current Terrain owners can rest easy, as 2018 and newer models have a completely different headlight assembly.  Recalls GMC Ownership Safety Crossover SUV

GMC boss wants a Jeep Wrangler rival

Challengers come and challengers go, but the Jeep Wrangler continues to push forward even after vehicles like the Toyota FJ Cruiser and the entire Hummer brand have been shut down. Now GMC reportedly wants to take a stab at the quintessential Jeep, as well.
The news comes directly from Buick-GMC vice president Duncan Aldred, speaking with our compatriots over at Edmunds. Although Aldred said there are no plans currently on the table to expand GMC's lineup beyond the current range, "there is plenty of room everywhere in the hierarchy."
That could include a rival to the Wrangler, as well as a flagship luxury SUV positioned above the current Yukon Denali (pictured above). Just when (or for that matter, if) such models might come into fruition remains a big question mark, but it's certainly interesting to see what GM's dedicated truck brand has on the drawing board.