1994 Chevy Suburban on 2040-cars

Auto blog

How GM engineers are using diaper 'snow' to keep you warm

Testing how snow affects General Motors' vehicles isn't really a problem right now for the company's engineers, but in the dog days of summer the process isn't exactly easy. The only real option is for them to book time at the automaker's climatic wind tunnel. However, a flash of brilliance from an engineer allows snow to be simulated regardless of the temperature outside, and the discovery is all because of his daughter's wet diaper. The realization came to GM Thermal Systems engineer Nicholas Jahn while he was swimming with his daughter and noticed how her diaper ballooned in size in the water. He found out the substance that makes this possible is called sodium polyacrylate. When the material gets wet it grows and forms fluffy flakes that are a close imitation of snow. Best of all, the stuff can be prepared easily any time of the year, and it's reusable. The engineering team uses the material to test the effectiveness of the heating systems of GM's vehicles. They spread the sodium polyacrylate over the inlets at the base of the windshield to obstruct the airflow and then crank the heater. After some time, they can see how much is being sucked into the system and design more efficient systems in the future. See how the process works in the video above and read about the diaper discovery in GM's press release below. Diapers Change Chevy Cruze Winter Warm-up Time GM validation engineer uses diaper material "snow" to reduce frigid drives 2015-01-06 DETROIT – An item commonly found on an infant's changing table is helping General Motors' engineers simulate snow year round, ensuring heating systems in cars like the 2015 Chevrolet Cruze can quickly and efficiently warm its interior. Packed snow can prevent air from entering the inlet panel at the bottom of the windshield, obstructing the flow of air into the heating system and reducing the amount of air it can push out. This can lead to less efficient warming of the car's interior and windshield defrosting. "The last thing anyone wants to do when it's freezing cold out is scrape their windshield," said Nicholas Jahn, GM Vehicle Thermal Systems engineer. "The testing we perform on the Chevrolet Cruze with the diaper material allows us to maximize the car's heating capabilities." Ironically, Jahn stumbled upon his diaper-based testing method in the middle of summer. During a swim with his daughter, he noticed her diaper multiplied in size when it came into contact with water.

Driving Granatelli's turbine-powered 1978 Chevy Corvette [w/video]

With its curvy snout and feminine haunches, the third-gen Chevrolet Corvette looks like a dreamy – if dated – exemplar of Sports Car Fantasy 101 when viewed through modern eyes. This particular specimen circa '78, clad in silver and black paint with red pinstripes, appears to be a well-preserved example from the era. Apart from its low-profile Pirellis, slightly raised and slotted hood, spacious stance and a certain hand-painted descriptor alongside its crossed flag logos, you'd never guess there's a Space-Age propulsion unit powering this Coke bottle-bodied ride. Climb inside, and you're presented with aircraft gauges and big, colorful square buttons in the center panel. It takes a push of the "Ignitor" button, a tap of the starter button, and a slide of a T-handle for this nearly 40-year-old sports car to start sounding like Gulfstream G650 ready for takeoff. Yep, you're sitting in an 880-horsepower, turbine-powered Corvette, the only one of its kind in the world. Welcome to the whoosh. What The...? Built by Vince Granatelli, son of Indy 500 guru Andy Granatelli, this curious Corvette came into being by cramming a Pratt & Whitney ST6N-74 gas turbine engine into the donor car's lengthy front end. The same type of Jet A-burning mill powered Granatelli Senior's STP-sponsored racecar at the 1967 Indianapolis 500, where it famously led most of the 198 of 200 laps until a $6 transmission bearing failed, knocking it out of the race. The idea of turbine power usurping internal combustion was so threatening that Indy's governing body restricted turbine performance into obsolescence thereafter. A turbine-powered Corvette sounds excessive because it is. But there are also things about this 880-horsepower, 1,161-pound-feet monster that might surprise you. While it smacks of futurist exoticism and cost a then-dizzying $37,000 in 1967, the Canadian-built powerplant uses 80 percent fewer parts than an internal combustion V8 and will run on virtually anything combustible – whiskey, diesel, even Chanel No. 5. Though it's triple the length of a V8, the Pratt & Whitney beast weighs only 285 pounds. It's also one hell of a robust workhorse, typically serving as an auxiliary power unit for commercial aircraft or a generator in oil fields, where it can run for tens of thousands of consecutive hours before needing an overhaul. To adapt the Chevrolet for jet duty, the nose section was gutted and a sub-frame was built to compensate for the loosey-goosey front end.

GM opens official investigation into C8 Corvette transmission leaks

In March 2020, a month after Chevrolet began customer deliveries of the 2020 C8 Corvette, a GM dealer technician created a Reddit thread about a leaking gearbox in a Corvette with 32 miles. That car hadn't even been sold yet. Since then, as a search of "C8 Corvette transmission leak" shows, it's been tales of woe for some owners. Something in the Tremec TR-9080 transaxle in the back of the mid-engined Corvette doesn't work as it should, the fault able to cause codes that the transmission needs service, or that the driver needs to shift to park. In some cases, the battery would die because of follow-on issues after the initial transmission code, that code preventing the car from powering down. As Autoevolution reports, GM filed paperwork with the National Highway Traffic Safety Administration in August to look into what's going on. Between forum threads and GM's investigation document, there are several issues mentioned. The most common appears to be the dual-clutch transmission leaking fluid due to gasket failures like the one suffered by one owner at 858 miles, and another for an owner currently enduring a second leaking transmission. The Midengined Corvette Forum reported that Chevy engineers redesigned the TR-9080 pan, fitting Corvettes with the new unit at some point in the 2021 model year. The original pan was stamped steel unit affixed to the engine with two studs and 13 bolts, plus "reinforcement plates." The updated pan is said to be a cast aluminum unit affixed with two studs and 17 bolts, omits the reinforcement plates, and gets a new machined new groove around its edge to seat the gasket seal. The GM paperwork now at the NHTSA mentions a P1789 code, and says one reason for it could be "debris on the park position sensor magnet causing an incorrect position reading to the TCM." This might be caused by another issue mentioned in forums, which is clogged transmission filters. GM gives instructions for returning transmission filters to the company, and a poster on one forum said the Corvette tech at the dealer where he bought his Corvette told him the automaker "requires every used transmission filter to be returned to GM."  Whatever's going on, the problems haven't stopped, and they go beyond the P1789 code. Over the weekend, a 2022 Corvette owner posted on Corvette Forums that he got a check engine light on his car after just 850 miles.