The concept raises more than a few eyebrows, but DuPont officials say they're confident a plastic radiator is doable. Made of a modified nylon 6/6 resin, DuPont engineers argue that a plastic heat exchanger could be shaped to fit any available space and moved to the wheel well or tucked behind the front fascia. That could free up plenty of real estate in the engine compartment, allowing designers to drop hood lines and further enhance cab-forward designs.

John R. (Jack) Levi4s, DuPont's director of engineering materials, admits that "more than a few engineers still find it difficult to conceive of nylon, a natural insulator, working as well as metal, which conducts heat."

However, he says the plastic design is composed of thin nylon layers through which the coolant flows, rather than conventional metal fins that merely conduct heat away from the metal tubing. The heat transfer efficiency comes from the much greater surface area that the coolant is exposed to through the thin-walled construction. Skeptics also wonder how nylon, which has a strong tendency to absorb moisture, could do April 1995 well in such an application, but Mr. Lewis seems confident that problem also can be hurdled. Field trials already are under way on some diesel-powered military vehicles. Non-automotive commercial applications could appear in 2 to 3 years.

SEAT WITH A MASSAGE

Vermont-based Ergomedics Inc. introduces a product designed to increase driver comfort during lengthy stays behind the wheel. BackCycler gently moves the spine back and forth, shifting patterns of stress on the vertebrae, increasing fluid movement in and out of the discs.

The microprocessor-controlled seat support is available as a portable unit and is being incorporated into Lear Seating Corp. products. Volvo Car Corp. also is incorporating BackCycler into some designs.

ACTIVE ROLL FOR SUV'S

As an offshoot of its active-suspension system, TRW Inc. displays an active roll control it says will improve both ride and handling of future sport/utility vehicles. TRW says the system will be on a production vehicle in a few years.

Designed to offer easier cornering with less body lean and better road feel, active roll control uses sensors to detect lateral movement and hydraulic pressure to move computer-controlled stabilizer bars to steady the vehicle.

Chester O. Macey, executive vice president and GM of TRW's steering, suspension and engine group, says 4-wheel-drive vehicles with high centers of gravity are perfect candidates for active roll control. Mr. Macey adds that TRW has talked with Bosch, Kelsey Hayes and ITT Automotive about incorporating active roll control in a vehicle dynamic control package.