A Dodge Omni electric car was prepared for competition in an electric “stock car” 2-hour endurance event: the inaugural Solar and Electric 500 Race, April 7, 1991. This entry utilized a series-wound, direct-current 21-hp electric motor controlled by an SCR frequency and pulse width modulator. Two types of lead-acid batteries were evaluated and the final configuration was a set of 16 (6-volt each) deep-cycle units.
Preparation involved weight and friction reduction; suspension modification; load, charge and temperature instrumentaltion; and electrical interlock and collision safety systems. Vehicle testing totalled 15 hours of operation. Ranges observed in testing with the final configuration were from 30 to 52 miles for loads of 175 to 90 amperes. These were nearly constant, continuous discharge cycles. The track qualifying speed (64mph) was near the 68 mph record set by the DEMI Honda at the event on the one-mile track.
Based on test data, a strategy was developed for the event to allow 2 hours of continuous operation, while maximizing distance traveled. This resulted in a plan of 90 amperes at approximately 30mph.
Improvements are necessary in transmission gear ratios, motor controls and battery energy density to improve overall performance. Other plans for development include possible conversion to hybrid operation (with a range extender I. C. engine) and supplemental power supplies such as a thermoelectric waste heat generator.