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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).

Junkyard Gem: 1973 GMC Sierra Grande Camper Special

Starting in the 1973 model year, General Motors introduced the "Rounded Line" family of C/K-series Chevrolet and GMC trucks, and sales of the pickup versions continued all the way through 1987. Nice examples of these trucks can sell for large money, but the junkyard teaches us that not all collectible vehicles are worth rescuing and fixing up. Here's a reinforcement of that lesson, courtesy of a first-year GMC C2500 Camper Special with the high-zoot Sierra Grande trim level, found in a self-service yard just outside of Denver, Colorado. I'm no GM truck expert, but I know enough to stay clear of the battles over what to call this pickup. Let's just say it's a three-quarter-ton, rear-wheel-drive third-gen C-Series with really cool badges. Yes, I bought this badge for my garage wall, and it was totally worth the $4.23. GM came up with the Camper Special package during the late 1960s, when removable pickup campers became popular, and for 1973 it included heavy-duty springs and a wiring harness made to plug into the connectors on slide-in truck campers. It also included woodsy-looking badges, but someone pried the ones off this truck before I could buy them. This may well have been a one-owner truck, because it still had original warranty paperwork inside. Here we see that it was purchased new on August 2, 1973 (which happens to be the day that George Brett got his very first hit in the big leagues) by a resident of Compton, California. Yes, that Compton. The build tag tells us that this Camper Special was born at the Fremont Assembly plant in California, which became the GM-Toyota NUMMI venture in 1984 and is now the Tesla Factory. I think most 1973 C/K pickups sold new in Colorado would have come from Pontiac Assembly in Michigan. There was a time, not many years ago, when a genuine 454-cubic-inch (that's 7.4 liters to those of you sweating under the oppressive weight of the French Empire's Measurement System) big-block Chevrolet engine would have been yanked out and purchased within hours of hitting the rows of a yard like this. These days, engine-swappers can get more power with less weight from any number of donor vehicles. If this engine is the original 454, it was rated at 240 horsepower and 355 pound-feet (down from 270 hp in 1972 due to emissions-related changes). This truck had a three-speed automatic transmission, like most optioned-up Detroit pickups of its era.

Watch GM's new pickup crash its way to five-star NHTSA ratings

General Motors has just scored a big win with its Chevrolet Silverado and GMC Sierra pickup trucks, acing the National Highway Traffic Safety Administration New Car Assessment Program. The two full-size trucks had already netted a five-star Overall Vehicle Score in their crew-cab variants, but the new testing certifies them as five-star trucks in both regular and double-cab bodystyles, so GM's trucks offer top ratings across the board.
"Our incredibly capable trucks have been engineered to be some of the safest," Gay Kent, GM's general director of Vehicle Safety and Crashworthiness said. "We've designed the vehicle structure, strategically placed high-strength steel and developed the occupant restraint system to achieve high levels of safety performance."
The scores mark the Silverado and Sierra as the first pickups to net five-star scores since NHTSA beefed up their testing regime in 2011, a nice feather in GM's cap as it continues to slug out the pickup truck wars with crosstown rivals Ford and Ram.