2001 Chevrolet Silverado 2500hd Duramax Allison 4x4 Crew Cab Longbed Project on 2040-cars

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GM patent reveals new two-stage turbocharger

Modern turbochargers may be some of the best ever made, but performance is something that engineers are always trying to improve. According to GM Inside News, General Motors (GM) is hoping to alleviate some of the negative aspects of a two-stage turbocharger setup with a newly-patented design. The patent, that was filed on May 19, 2016, reveals a clever bypass system that allows the engine, a four-cylinder unit, to optimize both the low-pressure and high-pressure inlets for its respective functions. According to the filing, a conventional two-stage turbocharger setup is engineered to allow both turbines to operate simultaneously at low and mid engine speeds. At high engine speeds, only the low-pressure turbine works. The setup can't isolate either the low or high pressure side, which can impair low-end performance. GM's new two-stage turbocharger setup looks to eliminate this by linking the high-pressure turbo to the exhaust manifold through the high-pressure inlet duct. The low-pressure turbo is attached to the high-pressure turbo by a low-pressure inlet duct, which is linked to a connecting channel. A single actuator that is housed in the exhaust manifold creates a bypass that can opens the high-pressure inlet or close the connecting channel. Depending on what the engine load and speed is, the ECU guides the actuator—a single rotating spindle with discs corresponding to flanges on the high and low pressure sides—to isolate one of the two turbos. Isolating the turbos allow the respective inlets to be engineered for the best possible fluid dynamic performance. The setup should increase performance and decrease lag. There's no word on what car this setup will make an appearance on, but it will most likely be used in premium vehicles before trickling down to the rest of GM's vehicles. Related Video: News Source: GM Inside News, AutoGuide via GM Authority Cadillac Chevrolet GM Technology Sedan turbo patent engine turbocharging

Diesel details: Comparing Ram 1500 EcoDiesel, Chevy Silverado Duramax, Ford F-150 Powerstroke

With specifications for the 2019 Ford F-150 Power Stroke diesel already out, and the details on the 2020 Ram 1500 EcoDiesel and Chevy Silverado Duramax (and its GMC Sierra twin) trickling out, we felt it was a good time to start comparing the full-size trucks' light-duty diesels. Bear in mind, we've only driven one of these new diesel trucks, so we'll be sticking to numbers for now. Some numbers haven't been announced yet, either, but stay tuned, because we'll be updating this post with additional specifications as they become available. And if you want to compare any other versions of these trucks with other vehicles, be sure to check out our comparison tool. Now let's start comparing, starting with our big chart of numbers below. As we can plainly see, these trucks are quite closely matched. Each one has six cylinders, a displacement of 3.0 liters and a turbocharger to boost it. The output of each is somewhat close, too. The Ram 1500 EcoDiesel is the torque king at 480 pound-feet, 20 more than the GM trucks and 40 more than the Ford. The GM trucks win on power, though, with 277 ponies, 17 more than the Ram, and 27 more than the Ford. GM does report that you get their trucks' peak 460 pound-feet of torque from 1,500 rpm to 3,000 rpm, whereas the others only report peak torque at a particular point in the rev band, but all of these trucks should have wide, flat torque curves as you would expect from modern turbodiesels. 2020 Ram 1500 EcoDiesel View 8 Photos Engine output is only one part of the truck performance equation. We also have towing and payload capacity, as well as fuel economy. With towing, the Ram 1500 is the current leader with a maximum capacity of 12,560 pounds. That tops the Ford F-150's 11,400-pound tow rating by well over 1,000 pounds. The F-150 can carry 2,020 pounds in its bed, but we don't know yet whether that's better or worse than the Ram or the GM trucks. We also don't have numbers for the GM trucks' towing capacities. View 9 Photos As for fuel economy, the Ford F-150 manages a thoroughly impressive 22 mpg in the city and 30 on the highway with two-wheel drive. Choosing four-wheel drive drops those numbers to 20 and 25 respectively. The fuel economy numbers for the Ram, Chevy and GMC haven't been revealed yet, but for some comparison, we can look at the old Ram EcoDiesel. That truck's best fuel economy was 20 in the city and 27 on the highway with two-wheel drive.

GM alerting truck and sedan owners to a do-over on brake recall

A recall campaign intended to address issues with braking systems on certain 2019 General Motors trucks and sedans may have introduced a new issue, the automaker has acknowledged, and thousands of owners driving repaired vehicles may need to return to their service departments for another update.  The update addresses a fix that was pushed out to owners of more than half a million brand-new GM trucks and sedans that could potentially lose partial braking function, according to the Detroit Free Press. The original software fix helped address situations where the vehicles' anti-lock braking systems would become disabled, which in turn would prevent electronic stability control from activating. Vehicles subject to the recall would often experience software glitches that prevented them from properly communicating the operational state of these systems, meaning drivers would have no idea that their brakes may not behave as expected in an emergency. The 2019 Chevrolet Silverado 1500, Cadillac CT6, and GMC Sierra 1500 were all recalled in the original campaign.  Unfortunately, the early version of this fix appears to have introduced yet another software glitch, indicating that the original fix did not do the trick. Those who have not yet had their cars serviced can rest easy; they will only receive the most up-to-date version of the software fix.  Related video