Building the Future

Article From: 11/1/2001 Automotive Design & Production, , Senior Associate Editor


This is the direction that the people at Hypercar think autos should take—not merely in terms of body design, but with regard to its composite-intensive manufacture.


The Virtuous Cycle. Hypercar’s clean-sheet design for super-efficiency started with a radical reduction in weight. It has been estimated that less than two percent of the energy a vehicle uses actually ends up transporting its passengers. The rest is lost to aerodynamic drag, rolling resistance and hauling around three or four thousand pounds of steel and glass. Reducing weight begets a virtuous cycle in which powerplants, braking and steering systems and suspensions can be downsized because there is less weight to propel, stop and turn.

With this in mind, the Revolution’s design team jettisoned the traditional steel body in favor of composite structures that provide strength and rigidity characteristics comparable to steel, at half the weight. This decision alone opened the door to a panoply of advantages...and disadvantages.

The Upside. First, the advantages: Using composites as a body material can greatly reduce the complexity of a vehicle by markedly decreasing part count. Hypercar estimates that a conventional car body is constructed of between 250 and 300 separate stamped steel parts. By contrast, since plastic can be formed into more complex shapes than steel, the Revolution has only 14 major components and a total of only 62 components in its entire structure.

Tooling costs can be minimized since you don’t need the expensive hard tools necessary to stamp all of that steel, nor do you need the complex jigs that hold metal parts in place while they are welded. (The Revolution’s structural components have been designed with self-aligning joints that reduce the need for jigs.) And speaking of the weld department, scratch that too, and all the fixed investment that goes into it.

Ditto for the massive investment and emissions headaches of the paint department. The Revolution’s thermoplastic exterior body panels have molded-in color.

The Downside. Now the disadvantages: Carbon-reinforced polymers like those used for the Revolution’s structure are typically laid up by hand at the rate of 30 or 40 plies per 1/8 in., making it a very labor intensive process. Unlike steel part manufacture, where most of the investment goes into hardware, with composite fabrication, the bulk of the cost goes to labor. As volumes rise, steel parts get cheaper, but composites have a built-in recurring labor cost that becomes prohibitive at higher volumes. Also, though the soft tooling needed for composites is cheaper than the hard tools for stamping steel, it wears out faster. So, at higher volumes, composite production tooling costs rise significantly.

As for thermoplastic panels, their cycle times are much longer than those for stamped steel, and molded-in color cannot yet reliably achieve class A surfaces on large panels.

The Solutions. To deal with the labor-intensiveness disadvantage, Hypercar is trying to take experience gathered in the aerospace industry and modifying it to fit automotive. David Taggart, senior vice president of Product Development, and leader of the core design team, spent much of his career at Lockheed Martin’s Skunk Works focusing on using carbon-reinforced materials for aircraft. He says, “While the requirements for a car are very different than an airplane, they are not so radically different that you can’t use the same approach. The biggest difference on the car is that we had a production volume requirement that is higher, but we also had different requirements for tolerances and specs on the materials that gave us some freedom and latitude on how we came up with solutions. So we exploited aerospace thinking but we blended it with production reality.”

The result is a proprietary production process. Though Taggart won’t divulge details, it is clear that his team is developing an automated process that can generate composite structures. He says, “We are convinced that you can’t get the quality, repeatability and cost necessary by doing it by hand and using a lot of labor.”

Hypercar has set itself the goal of developing technologies that can cost-effectively produce Revolutions at the 50,000 unit per year level. According to Taggart, no company has been able to make composites affordable at that volume, but he reckons that that is the number necessary to get the automakers to sit up and take notice.

Currently, the project has progressed to the point that if the design was frozen and all efforts were placed on scaling up production, Taggart thinks the Revolution would be price competitive with the BMW X5. The next phase will be a two-year engineering/manufacturing development period after which the goal is to be price competitive with a Ford Explorer.

Hypercar is not looking to become an automaker. The company sees its role as a developer of the technologies needed to make cars. It wants to license its handiwork to existing makers or companies that want to produce niche vehicles at low investment rates. And, if Hypercar can deliver a super-efficient car for the price of a conventional one, it may have lots of takers.

Beyond the Body Structure
The extensive use of lightweight composite structures has allowed the Hypercar design team to achieve a curb weight of a mere 857 kg, which is less than half the weight of the similarly-sized Lexus RX300. But weight savings alone will not get the Revolution to its product requirements of 100 mpg with zero emissions. Here are some of the other technologies at work:

  • Electric motors on each wheel powered by a hydrogen fuel cell
  • Michelin’s PAX wheel and tire system that reduces rolling resistance by as much as 50% over comparable vehicles
  • Integrated digital electronic control for all systems that reduces wiring complexity, mass and assembly time
  • Sidestick steer-by-wire system that eliminates the steering wheel and column and the need for an adjustable driver’s seat
  • Optimized aerodynamics that are estimated to be 30% to 40% better than a conventional SUV.

If This Is Such a Good Idea...

So if making cars with composites is such a good idea, why aren't traditional vehicle manufacturers aggressively pursuing the technology? David Taggart, Hypercar's senior vice president of Product Development, answers, “Because no one is asking for it. At least not on the level that we've tried to design to. No one is saying I need an SUV that gets 100 mpg. Customers are saying give me an SUV that gets 22 mpg, and you don't have to take a lot of weight out to get to that. Until the challenge gets a little more dramatic you will get what you get now, which is a few tweaks here and there with a slow progression toward something that Americans might say is economical but that the Europeans say is a joke. Until there is a demand for product it won't be delivered. Also, people don't realize that they have a choice. Part of what we are trying to do is show companies and the public that there is another way to design and build cars that delivers much more attractive economy and emissions.”