Darko Technologies was the only wind tunnel west of Detroit that was big enough to test full-size vehicles. The tunnel was used to test aerodynamics for cars, bicycles, motorcycles, and even Olympic skiers. We use the past tense because, as of this printing, Darko Technologies has shut down its wind tunnel. The tunnel was self-contained inside a closed building. The huge fans look like some sort of tail section from a scifi movie. Air exited through three 150-horsepower, six-foot diameter turbines. The air circulated around the side of the testing area and back into the front of the booth. The fans moved air through the wind tunnel chamber at 76 mph. Software allowed them to calculate much higher speeds. The computer was reading from the sensors it parked on in the floor and under the car. The data collected for Big Red was calculated to give readings of 260 mph. The side of the tunnel opened up to allow Big Red to be pushed inside. At the front of the tunnel, there was a honeycomb screen wall that straightened the air as it entered the tunnel.
The whole testing process was viewable from the control room. Layne Christensen, the owner of Darko Technologies, ran the wind tunnel from his computer and oversaw the entire testing process At the front of the tunnel, there was a honeycomb screen wall that straightened the air as it entered the tunnel. The whole testing process was viewable from the control room. Layne Christensen, the owner of Darko Technologies, ran the wind tunnel from his computer and oversaw the entire testing process Along with the extra hoods and trunk lids, the team brought the narrow BBS front wheels they used at Mojave and other Top Speed events. They have always thought that they needed to run narrower front tires to tuck inside the front fenders a little more (compared to the wider Road Race wheels and tires). The wind-tunnel testing showed that they could run the wider tires in the front from now on. The narrower front tires didn’t help reduce drag. The bonus was that the wider tires have a better speed rating.They installed a two-inch cowl hood with a hole for The Elephant’s new Hi-Ram intake manifold. Compared to the other hoods with smooth-cowl hood scoops
, this hood didn’t perform as well in regard to downforce and drag. Dave brought a front section of an old splitter. He clamped it to the bottom of the splitter, but stuck it out a couple of inches. He found that a longer splitter made a considerable difference in downforce. Tim removed The Elephant’s Hi-Ram in order to install a few other hoods. Luckily, the guys already had unbolted the intake back at the shop, knowing it would be removed for wind-tunnel testing anyway. They installed the four-inch cowl hood, which created less lift than the two-inch cowl hood. The four-inch cowl hood scoop was closed to the base of the windshield with cardboard and high-speed racing
tape. This was a big improvement for the hood.The four-inch cowl was the best of the cowl hoods so far. They went back to the two-inch cowl hood without the splitter extension. The next hood (all red) was the custom three-inch carbon-fiber hood they built to run at Pikes Peak. They also removed the splitter extension, with expected results
To get an idea of how Big Red’s numbers were affected by simulating a full tank of water, they loaded Big Red’s trunk with lead plates. An interesting find was that the factory rear spoiler created a little bit of lift over 150 mph. That’s a scary thought, considering RJ ran 222 mph at the Silver State Classic Challenge and Mojave with this spoiler. It’s no wonder Big Red was a little unstable at 220 mph. The crew swapped the rear spoiler with a custom height spoiler, which was an original spoiler that they had modified to gain extra height. It’s a subtle change, but the lift decreased. The best rear spoiler is the Land Speed/Top Speed setup. The wind-tunnel readings went from a little lift with the stock spoiler to actual downforce.For the heck of it, they removed the rear bumper to see if it changed the aerodynamics. It does hang out over the quarter panels, so it was worth a look. The drag was reduced slightly, but it wasn’t enough of a change to warrant removing it for good
Overall, the trip paid off big time. They felt vindicated with many of the modifications they had made over the years. The shape and size of the front air dam will be scrutinized in the future if they can make effective changes without pushing the car into a different class. The boxing up the back of the hood scoop to the windshield also will be addressed in the future. Running wider tires and bigger rear spoilers didn’t create unwanted drag. Every little bit will improve Big Red’s speed on the top end, while improving RJ’s safety. Dan and RJ’s mission with Big Red was to build a competition-eating Camaro that stayed true to the Camaro form as much as possible. The team has stuck to that rule since the beginning. Big Red’s grille is a huge air pocket, so they added a Lexan™ panel to close it. The Land Speed/Top Speed hood scoop started as an aerodynamic Pro Stock scoop to improve airflow to a pair of carburetors mounted atop a tunnel ram. When the Pro Charger was added, the scoop was closed with an aerodynamic cover; the
scoop stayed in place to cover the supercharger’s intake tube. The crew took Big Red to Darko Technologies to test the performance of the aero it already had achieved to this point. It also wanted to test how different parts work together, and how they could improve the Big Red brick to better cheat the wind. Film crew member Justin Shell was on the job to record the windtunnel process. He found out that he’s not aerodynamic. Aeronautical Engineer Tom Burkland stepped into the wind tunnel with the smoke wand and moved it around the aero hood scoop. If the smoke trail starts to break up, it’s getting turbulent. Slippery is faster than turbulent. When running the big Land Speed/Top Speed spoiler, the team always left the adjustable trunk lid spoiler in the center adjustment hole, so theywouldn’t create a lot of drag. In the tunnel, they lifted up the spoiler’s flap to the top adjustment hole and found that it created more downforce and little drag. Layne checked the data on his computer between tests. The crew brought five different hoods and three different trunk lids (with different spoilers). The team didn’t bring the narrow Land Speed wheels, so the salt-flat disc covers had to be taped to the BBS wheels and Hoosier Road Race tires. The covers kept air flowing around the car smoothly and created less drag, which also settled the car
