If You Find a Road With No Speed Limit ...

IT'S sleek, it's fast, and for the moment, it's not for sale. But based on the reaction to Chrysler's new Viper at the recent Detroit Auto Show, it could be the automaker's top-of-the-line sporty muscle car sometime in the 1990s.

``It's a great car,'' said Tony Godo, an assembly-line worker from Windsor, Ontario, as he elbowed his way through a crowd surrounding the Viper display. ``It's like an airplane. It's really hot.''

While many of the prototypes displayed on the auto-show circuit this year boast the latest in aerodynamic styling and high-tech electronics, the Viper is something of a throwback, Chrysler officials say. With its 10-cylinder engine, the emphasis is on muscle, not electronics.

The Viper is far afield of the cars that Chrysler has been turning out through most of the '80s. The No. 3 automaker has the highest corporate fuel economy of any domestic manufacturer, primarily because of its front-wheel-drive models equipped with modest-sized four- and six-cylinder engines. The Viper, on the other hand, is designed to be powered by a newly designed V-10 engine that will turn out more than 350 horsepower.

Offering engines bigger than the V-8 has become a sort of industry status symbol, says Thomas Gale, Chrysler's vice-president of product design. With oil prices remaining stable and relatively cheap, ``muscle cars'' in general have been making a comeback in the United States. Though most European automakers have seen a slump in demand over the past 12 months, there are waiting lines for some of the most expensive, high-performance imports, such as the V-12-equipped BMWs and Jaguars.

Chrysler's entry into the ultra-power race would be the biggest US-made engine. It would also be one of the most powerful engines on the highway. ``It will enable us to reach the upper end of the market,'' Mr. Gale says.

The long-rumored 8-liter V-10 is expected to make its debut sometime in the early 1990s. It is designed to be used in both passenger cars and light trucks, according to company officials, though Chrysler president Robert Lutz says ``we might want to do a sports car first.''

That creates a bit of a problem. The V-10 is far too powerful for any Chrysler car now in production and it's highly unlikely any of the automaker's front-wheel-drive cars could be modified enough to make the grade. So something would have to be designed around the brutish engine, and the Viper could be it.

Although the V-10 has gotten a preliminary go-ahead, Chrysler officials say that its fate - and that of the Viper - will depend in part on Congress. If the current fuel economy standard of 26.5 miles a gallon is sharply increased, it might squelch the demand for high performance cars. ``It might be a program we'd have to cancel,'' says Mr. Lutz.

Otherwise, insiders say, the Viper has a good chance of making it into production in limited numbers by the early to mid-1990s.

As for price, Chrysler planners say you should expect it to be above $40,000.