1971 Chevrolet Cheyenne Short Wide 4x4 on 2040-cars

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GM will recall 3.5 million pickups and SUVs to fix brake issue

WASHINGTON — General Motors Co is recalling 3.46 million U.S. pickup trucks and SUVs to address a vacuum pump issue that could make braking more difficult and increase the risk of a crash. The recall, which covers 2014-2018 model year vehicles, including some Cadillac Escalade, Chevrolet Silverado, Chevrolet Tahoe, GMC Sierra, Chevrolet Suburban and GMC Yukon vehicles, was triggered because the amount of vacuum created by the vacuum pump may decrease over time, GM told the National Highway Traffic Safety Administration (NHTSA) in documents posted Wednesday. NHTSA opened a preliminary investigation into the issue in November 2018, and said it had reports of 9 crashes and two injuries related to the issue. It provided GM in July with additional field reports that prompted the automaker to open an investigation. The company did not immediately say on Wednesday how many injuries or crashes are linked to the issue but said it could impact braking in "rare circumstances." GM said dealers will reprogram the Electronic Brake Control Module with a new calibration that will improve how the system utilizes the hydraulic brake boost assist function when vacuum assist is depleted. GM said the vacuum assist pump, which is lubricated with engine oil that flows into the pump through a filter screen, can in some cases lose effectiveness over time, as debris such as oil sludge can accumulate on the filter screen. GM told NHTSA that prior model years used a different brake assist system design, and vehicles manufactured after 2018 were not equipped with the affected pump design. Recalls Chevrolet GM GMC

'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).

Camaro spy shots show subtly different grille, front fascia

It looks like there some changes in store for the Chevrolet Camaro - the only thing is that we just don't know what Chevy has up its sleeve. Looking at these spy shots, we'd initially be inclined to think that there is just a minor facelift or a new special edition, but upon closer inspection, there are a few oddities about this car that definitely have us intrigued.
The most obvious difference on this prototype is the slightly restyled front fascia with a smaller lower air inlet and the two-bar grille. Then we get to some of the car's mysterious details. For starters, this fascia has the SS vent above the grille, but it looks to be blocked off. Granted this could just be a one-off piece used for testing. What really piqued our interest was at the rear of the car where it has quad exhaust outlets that are used on the ZL1. Could this be the LS7-powered Camaro that we reported on back in December?
At this point, your guess is as good as ours as to what we're looking at here, so let us know in the comments what you think this could be.