1999 Chevrolet K2500 Suburban 7.4l (454) 4wd on 2040-cars

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NHTSA closes book on Ford, GM probes of 600,000 vehicles

US safety regulators have closed a pair of investigations into some 500,000 Ford Crown Victoria, Mercury Grand Marquis and Marauder sedans built between 2004 to 2007, and 100,000 Chevrolet Impala models from 2014. The Ford investigation focused on rusting heat shields, which may become dislodged and jam the steering, according to Reuters. The National Highway Traffic Safety Administration found that this happened very rarely. In fact, of the ten incidents filed with the government safety watchdog, six came from a single police department, which evidently had some sort of problem with its reporting. As for the Impala, the NHTSA investigators attributed two incidences of "unintended autonomous braking" to user error. In both cases, the vehicles were involved in rear-end collisions. According to GM investigators, it's believed that drivers accidentally activated the electric parking brake, causing the collisions. The vehicles in question were rental cars. Featured Gallery Ford Crown Victoria Related Gallery 2014 Chevrolet Impala View 10 Photos News Source: ReutersImage Credit: Ford, Chevrolet Government/Legal Chevrolet Ford Safety Sedan ford crown victoria mercury grand marquis

2014 Chevrolet Corvette Stingray Convertible gives us a couple of looks

Put away your pixel paintbrushes, kids. Pack up your Photoshop. This is the real-deal 2014 Chevrolet Corvette Stingray Convertible in its first official images. The droptop Chevrolet will roll into the bright lights of the Palexpo exhibition at next week's Geneva Motor Show, a four-wheeled statement of intent that General Motors is serious about taking its Corvette franchise global.
Chevy isn't providing anything in the way of further details with these two shots, but we've learned at least a couple of things about the car shown here. First off, the example seen in these images is fitted with the optional Z51 Performance Package - something that isn't immediately evident because there's no sign of the coupe model's prominent ductwork on its rear haunches. In order to accommodate the power folding hard tonneau cover, the vents that feed the transmission and differential coolers have been relocated to the underside of the car. The dark paint color on this example also does a good job of muting the contrasting black front fender vents and hood opening - Z51-spec design details that have proven to be somewhat controversial.
One other thing to note: These two shots also display the Stingray wearing different alloy wheels than the split five-spoke design shown at the hardtop's Detroit Auto Show unveiling in January. The simpler, thin five-spoke wheels should do a good job of showing off the Z51's upgraded brakes, and they'll be optional on the coupe as well.

'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).