Thanks to MotorTrend, we have a tour of the Bowling Green Assembly Plant. Clicking on the link below will take you to another 17 photographs inside the Plant.
Read more: Visiting the Home of the Chevrolet Corvette Stingray - Motor TrendMotortrend said:For Chevrolet Corvette Stingray fanatics, the best welcome mat in America sits in southern Kentucky. It leads you into a modest foyer and through double doors, where you're greeted by multiple copies of the Corvette's mug painted in Torch Red, Arctic White, and Laguna Blue. In the distance, the silhouette of a Stingray-inspired coupe sits under harsh fluorescent lighting, while the roar from an LT1 V-8 coming to life for the first time echoes off the walls. This is the Home of Corvette -- a place where excitement can quickly turn into sensory overload. We witnessed this during a fast-paced tour of the factory. A group of General Motors employees, including Corvette chief engineer Tadge Juechter, made us feel right at home. If you've read our coverage of the C7 Corvette, you already know that we like the car a lot. "Refined" and "precise" are just a couple words we've used to describe the brand's flagship sports car and much of that can be attributed to the improvements made at the Corvette factory in Bowling Green, Ky., located about 500 miles south of Motor City and 70 miles north of the home of country music. In preparation for C7 production, GM extensively renovated the factory to the tune of $131 million, almost seven times the amount spent when Bowling Green switched from C5 to C6 mode back in 2005. More on the Corvette: Epic Drive - 2014 Chevrolet Corvette Visits Legendary NASA Space Sites Preparing for the renovation was no walk in the park. Thirty-three employees from the Bowling Green plant routinely traveled to GM headquarters to help plan the renovation. Every Monday morning the crew hopped on a plane to Detroit, stayed the week, flying back to Bowling Green on Friday. They did this for two years. Among those 33: Jon Andrews, who manages a new body shop that represents the bulk of the renovation investment. "I didn't get much sleep during that time," Andrews said. The body shop occupies a spot where the factory once produced the Cadillac XLR. The space includes no fewer than 90 robots and 30 employees working to build the Corvette's aluminum frame completely in house. The body shop will not be included in the public tour, so we spent much of our time here. "The biggest challenge was training my team how to work with aluminum," Andrews explained. "It's a whole different animal." The animal they've created is an all-aluminum frame weighing 306 pounds. Not only is it 99 pounds lighter than the C6's steel frame, but it's 57 percent stiffer. And among the many tools needed to put the frame together are three laser welding machines (the most expensive items in the shop), with each laser putting out about 5 to 6 kW of power through a tiny fiber optic tip just a tad thicker than human hair.
The light emitted by these lasers is intense. So much so that federal law requires these lasers to be enclosed in sealed booths that prevent any of the energy from escaping. A computer monitor allowed us to watch the lasers in action, as it welded items like the center tunnel assembly and the seat back. The lasers are extremely fast -- performing 37 feet of welds in just five minutes. The laser's concentrated energy means there's less overall heat to weaken the aluminum. It's similar to ironing a shirt -- an overly hot and slow moving iron will likely result in burned threads. After the laser station, it's time for the center tunnel to join the two main frame rails and the front and rear bumper beams. Here, traditional MIG welds are used, as well as high strength adhesives and a new flowdrill fastening system (Flowdrill). The flowdrill fasteners look like thick, one-inch nails and are drilled into the frame at high speeds. The heat and pressure created extrudes the aluminum before resulting in a screw-type fastener. GM says flowdrills are quicker, stronger, and provide a better seal than a traditional screw. Once the complete frame is assembled, it goes through a final inspection (TIG welds are used for any needed repairs) before going to pre-treatment (we were not shown this area, nor the section where the frame components are made). With the frame built and treated, it's time for general assembly. One of the first stops is installing the floor pan, which is constructed from carbon nano, sheet-molded compound (SMC). The lightweight composite, a mixture of carbon fiber, fiberglass, and nano clay, is also used to form the rear structure that frames items like the rear quarter window and hatch. GM points out that every part is assigned a car number, whether it's produced in-house or sourced from a supplier. The factory is packed with parts -- stored in crates, hanging on racks, or moving along on overhead conveyor belts. And all eventually make their way through the plant's maze before creating one C7. Another unique item to the Corvette is its cockpit module, which comprises the steering column, windshield frame, dashboard, instrument panel, and related electronics. About a third of the C7's total parts are contained in the cockpit module. Building this section of the car separately from the chassis allows easier access, testing, and, if necessary, repairs. When it comes to painting, most cars enter the station as an entire unit -- frames, doors, and all. Not so with Corvette. Since the C7's structural rigidity is not dependent on the body panels, they're painted separately and are added towards the end of the production line. One benefit is that the panels are less likely to be scratched or dinged while moving down the line. "It's really nice to build a car almost like a racecar chassis and just put those panels on at the end," Juechter told us. "That's actually another way that this is more like a racecar than a typical car." From general assembly, we move onto the marriage of the chassis and the drivetrain, perhaps one of the most popular stops on the tour. Here, one overhead conveyor belt carries a line of chassis, while a belt on the floor rolls in the drivetrains perpendicularly. And like a freeway onramp, the two eventually merge, as the chassis is carefully lowered onto the drivetrain. Here, the assembly line workers have very little space to work with, with some areas providing just one inch of spare space.
After its wheels are bolted on and a final paint inspection, the C7 is lowered onto the ground and is supporting its own weight for the first time. But before loading the C7 onto a big rig, it must pass a number of tests. First up is dynamic roll and brake test, where workers run the Corvette to 80 mph and ensure items like the transmission are running smoothly. Then it's off to a rain simulator to check for water leaks and a quarter-mile outdoor road course to check for squeaks and rattles. In all, it takes about three and half days to build a C7. The plant, which includes over 1000 employees, produces 17.2 Corvettes an hour, or 137 units daily. And improvements to Bowling Green are not done. As previously reported, GM is moving its Performance Build Center from Wixom, Mich. to Bowling Green. Set to open this year, the Performance Build Center will allow customers to build their own engines. We expect the center will build many of the range-topping engines used for the Corvette and other GM models like the Camaro. The plant ceased public tours due to the renovations, but GM has resumed tours, with the price of entry set at $7. And after going through the tour ourselves, we consider that price of entry a great value, much like the C7 itself.