Where do you start? Three words: Aerodynamics, aerodynamics, aerodynamics. "I have a nasty feeling that aero will squash everything else in terms of importance," says Kia Cammaerts, a motorsports software supplier who's spent countless hours analyzing racecars in wind tunnels.
The aero front is where engineers face the tightest restrictions. Ergo, it's where, unfettered, they can make the biggest gains. The first step, paradoxically, would likely be to clip the wings. Say what? Don't wings produce downforce, exerting a vertical load on cars and enabling them to corner like they're on rails? They sure do. In fact, the first generation of wings-inverted wings, to be accurate-caused lap speeds at Indy to skyrocket from 170 to 196 miles an hour between 1970 and 1972. But by the end of the decade, aerodynamicists had discovered a far more efficient way to generate downforce. Known as ground effects, this entailed fashioning an underwing-venturi-shaped tunnels carved from the bottom of the chassis-that creates a traction-enhancing low-pressure zone between the car and the road.
Ground effects worked so well that rules were immediately instituted to limit the size and shape of the underwing. But absent any restrictions, designers would create huge tunnels to corral as much air-and generate as much downforce-as possible. To increase efficiency, the tunnels would be sealed with "skirts" that would descend on command to rub against the pavement. Modern Formula 1 cars can generate about 2,500 pounds of downforce at 150 mph. With an anything- goes format, 10 times that much would be within reach.
But wait, there's more! Besides ground effects, designers would use suction-think vacuum cleaner-to develop additional traction. "It's so much more effective than anything else," says Paul VanValkenburgh, a car journalist and former engineer at Chevrolet Research and Development. There, in 1968, VanValkenburgh rigged a test chassis with a fan that sucked the car to the ground. A similar system was implemented in the Chaparral 2J Can-Am racer in 1970, and although the "sucker car" didn't win any races, it was so fast that vacuum technology was immediately banned. (In Formula 1 racing, a conceptually similar fan car won its only race in 1978 before being legislated into oblivion.)
The suction fan would either be powered by an auxiliary motor or run off the main engine. Unlike ground effects, vacuum suction isn't speed-dependent, so it develops great gobs of grip even in slow corners. Put vacuum technology and ground effects together, and you´re looking at negative lift-over-drag ratios of as much as 20-to-1. (Modern racecars top out around 3-to-1.) And maximum G-forces in the turns, which now range from 3 to 5, would easily double or even triple.
This will translate into cornering speeds so preposterous that humans may not be able to keep up. Three years ago, an Indy car race at Texas Motor Speedway was canceled after most of the drivers experienced headaches and dizziness-and that was at a mere 235 mph. It turned out their symptoms were probably caused by inner-ear imbalances due in part to high G-forces. And as speeds ratchet up beyond 300 mph, G-loads are going to get worse, making drivers look like those poor astronauts-in-training wearing ghoulish, stretch-face grins while riding high-speed centrifuges.
And drivers aren't the only ones who might look weird. Another consequence of a no-rules aero package is that cars wouldn't resemble the missiles we're accustomed to seeing. The wheels would be enclosed to minimize drag. So would the cockpit. But ground effects and suction technology work best in big areas rather than small, arguing for a large, boxy shape. "The ideal sucker body is a pickup truck," says Lee Dykstra, technology director for the Champ Car series. Then again, the bodywork could be designed to change shape as circumstances warrant-angling straight up to serve as an air brake, for example. "Computers would allow you to use variable aerodynamics," says designer John Ward, a race engineer in the Indy Racing League, "so you'd decrease drag on the straights and increase downforce in the corners."
After aerodynamics, power plants take pride of place in the no-limits race. Rockets merit consideration-retro-
rockets might be used to help a car turn and stop-and even nukes get a few votes. Hey, while we're at it, why don't we dust off the flux capacitor in Michael J. Fox's DeLorean? But seriously, folks, small gas turbines are the most attractive alternative to conventional four-stroke piston engines. In fact, cars powered by modified Pratt & Whitney helicopter turbines coulda woulda shoulda won the Indy 500 in 1967 and 1968 before (stop me if this is getting repetitious) being effectively outlawed. Turbines boast superlative power-to-weight ratios, and they're smaller and torquier than four-stroke piston engines. Also, thrust could be vectored, or angled, to help turn the car. What's not to like? Well, turbines suffer from throttle lag: They take time to spool up to speed, and they take more time to slow back down-not a good combo for racing.
Stay up to date on the latest news of the future of science and technology from your iPhone with full articles, images and offline viewing
Featuring every article from the magazine and website, plus links from around the Web. Also see our PopSci DIY feed
Share links with friends, comment on stories and more
In our December issue, Popular Science names the 100 best innovations of the year: bombproof wallpaper, self-parking cars, the fastest helicopter, and 97 more. Plus inventor profiles and videos.
Check out the best of what's new here.