Toyota Prius Sets Land Speed Record for Hybrid Vehicles

Now that the Bar has been Set Look for Others to Follow

If its got wheels and a motor, theres probably a class for it to set a record in at the Bonneville Salt Flats in the Utah desert. This kind of mentality has stuck with generation upon generation of automotive, truck and motorcycle enthusiasts who create their own vehicles in order to land a spot in the speed record books.

Once dominated by bucket-seat hotrods and chopped Fords and Mercurys, the scene at Bonneville has changed, with entries from all sorts of vehicles, ranging from one-cylinder motorcycles, to 1,600-horsepower diesel fire trucks, to V8-powered station wagons and, of course, jet-powered manned missiles that look more like wingless fighter planes than anything resembling a car.

One category in which the SCTA, the governing body at Bonneville, had a blank entry was for hybrid-powered vehicles. Toyotas Motorsport division jumped on the opportunity to be the first to set a record in this category with their gasoline-electric- powered Prius. Since the record books were empty, the team chose the line of least resistance by opting for a near-stock approach to the challenge.

The vehicle in question, prior to the application of its vivid green livery, started out as a randomly-selected production Prius. Toyota Motorsport did not change the cars trademarked Hybrid Synergy Drive system, which consists of a blend between a battery-powered DC electric motor and a small-displacement 1.5-litre 75-horsepower inline-four.

Though the Prius has a total horsepower rating thats eclipsed by nearly every midsize vehicle on the market, it does have an ace up its sleeve: the electric motor is unaffected by the thin air at Bonnevilles 4,200 foot altitude.

In order to extract the most out of the powerplant, Toyota Motorsports engineers made minor changes to the cars drivetrain to enhance the efficiency of its components. The final drive ratio was changed from 4.32:1 to 3.20:1 to improve top speed, while the voltage inverter was upped from 500 volts to 550 volts, a similar upgrade as was made to the Prius GT prototype racer displayed at this years Goodwood Festival of Speed. Both units were cooled from the 40°C air temperature of the desert with ice and cold water, to improve their performance and reliability.

To minimize airflow under the car and to make the best of the Prius wind-slippery 0.26 Cd body, the racer was lowered by a whopping 0.5 inches. Special Bilstein shocks and 3,600 pound-per-inch Eibach springs were used, making the cars suspension approximately 30 times stiffer than stock. The finishing touches to the car were specially-made Goodyear Eagle Land Speed Record ties measuring 26 inches at the front and 25 inches at the rear with aerodynamic wheel cap covers.

Inside, much of the Prius space-age interior was stripped out to reduce the cars weight. Aside from the lack of front passenger and rear seats, door panels and sound insulation, the modified Prius also featured a full tube-style roll cage and a 15-gallon tank for the ice-water circulatory system. Prepped and primed, the Prius ran the three mile-long "Short Circuit", designed for cars running at under 175 mph, at a speed of 130.794 mph.

Aside from its position as the fastest hybrid-powered vehicle, the Prius has proven its mettle in competition. The first-generation Prius was the first hybrid-powered car to compete in and finish an FIA-sanctioned event at the 4,970 mile Midnight Sun to Red Sea Rally in 2002, and was an active competitor in the Canadian Pro Rally series that year.

Off the track, the second-generation Prius has won international recognition by capturing the title of 2005 European Car of the Year, plus various other awards.