1978 Chevy Blazer Jimmy 2wd K5 on 2040-cars

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Is the skill of rev matching being lost to computers?

If the ability to drive a vehicle equipped with a manual gearbox is becoming a lost art, then the skill of being able to match revs on downshifts is the stuff they would teach at the automotive equivalent of the Shaolin Temple. The usefulness of rev matching in street driving is limited most of the time – aside from sounding cool and impressing your friends. But out on a race track or the occasional fast, windy road, its benefits are abundantly clear. While in motion, the engine speed and wheel speed of a vehicle with a manual transmission are kept in sync when the clutch is engaged (i.e. when the clutch pedal is not being pressed down). However, when changing gear, that mechanical link is severed briefly, and the synchronization between the motor and wheels is broken. When upshifting during acceleration, this isn't much of an issue, as there's typically not a huge disparity between engine speed and wheel speed as a car accelerates. Rev-matching downshifts is the stuff they would teach at the automotive equivalent of the Shaolin Temple. But when slowing down and downshifting – as you might do when approaching a corner at a high rate of speed – that gap of time caused by the disengagement of the clutch from the engine causes the revs to drop. Without bringing up the revs somehow to help the engine speed match the wheel speed in the gear you're about to use, you'll typically get a sudden jolt when re-engaging the clutch as physics brings everything back into sync. That jolt can be a big problem when you're moving along swiftly, causing instability or even a loss of traction, particularly in rear-wheel-drive cars. So the point of rev matching is to blip the throttle simultaneously as you downshift gears in order to bring the engine speed to a closer match with the wheel speed before you re-engage the clutch in that lower gear, in turn providing a much smoother downshift. When braking is thrown in, you get heel-toe downshifting, which involves some dexterity to use all three pedals at the same time with just two feet – clutch in, slow the car while revving, clutch out. However, even if you're aware of heel-toe technique and the basic elements of how to perform a rev match, perfecting it to the point of making it useful can be difficult.

GM recalls 3.6 million vehicles for airbag-software problems

The Basics: General Motors is recalling 3.64 million vehicles across its lineup for an airbag-related issue. The recall covers the 2014-2015 Buick LaCrosse, Chevrolet SS, and Spark EV; 2014-2017 Chevrolet Corvette, Trax, Caprice PPV, Silverado 1500, Buick Encore, and GMC Sierra 1500; and 2015-2017 Chevrolet Tahoe, Suburban, Silverado HD, GMC Yukon, Yukon XL, Sierra HD, Cadillac Escalade, and Escalade ESV. The Problem: Affected vehicles have a sensing and diagnostic module that controls the airbags and seat-belt pretensioners. The software it uses has a defect that can prompt the module to run a diagnostic test under specific driving conditions, which will also deactivate the front airbags and pretensioners. This means that it would be possible for those safety systems to not activate in a crash, potentially leading to injury or death. Injuries/Deaths: General Motors began an investigation that led to the recall after a 2014 Silverado was involved in a crash in which the airbags did not deploy. No information was given as to injuries or deaths. The Fix: Owners can bring their vehicles to a local General Motors dealer where a software update will be installed to fix the issue. The fix will be free of charge. If you own one: General Motors will contact owners of affected cars, and owners can check whether their vehicles are affected by visiting entering their vehicle identification numbers at either the GM Owner Center website or the NHTSA website. Owners can then schedule a time to have the update installed. Related Video:

UAW rejects GM contract proposal but makes a counter offer

The United Auto Workers union said a new comprehensive offer made by General Motors Co late Monday to end a two-week-old strike was not acceptable and said it had made a new counterproposal. UAW vice president Terry Dittes said in a letter to members "there are many important issues that remain unresolved." The union is awaiting GM's next proposal. He said GM's offer came up short on many issues.  Dittes said GM made a "comprehensive proposal" at 9:40 p.m. Monday. "This proposal that the company provided to us on day 15 of the strike did not satisfy your contract demands or needs. There were many areas that came up short like health care, wages, temporary employees, skilled trades and job security to name a few." Dittes is the union's vice president for GM relations and the UAW's lead negotiator in these contract talks. "We have responded today with a counterproposal and are awaiting GM's next proposal to the union," he wrote. "Regardless of what is publicized in print or social media, etc., there are still many important issues that remain unresolved." The strike, in its third week, has cost GM more than $1 billion, according to J.P. Morgan analyst Ryan Brickman. He said the cost per day in potential profit is $82 million. However, another analysis, by East Lansing-based consultant Anderson Economic Group, put the losses at $25 million a day. And the effects of the strike are expanding. GM said Tuesday the strike has created a parts shortage that forced the automaker to halt production at its pickup and transmission plants in Silao, Mexico, temporarily laying off 6,000 workers. Silao is where GM builds its highly profitable four-door crew cab Chevy Silverado and GMC Sierra pickups. The strike has also forced GM to idle some Canadian workers, and many suppliers have been forced to halt operations. About 48,000 UAW members went on strike on Sept. 16 seeking higher pay, greater job security, a bigger share of the leading U.S. automaker’s profit and protection of their healthcare.