Step One: Weights & Measures

Let the conversion begin! There are several factors that will eventually determine my performance with the electric motor. For my purposes I am defining performance as top speed and range on a full charge.

Two important performance factors have already been removed from the equation, as I have already decided on a 9" series-wound DC motor, running on 156 volts. The remaining factors have to do with the car itself.

The most important variable with the car is the weight. Also somewhat important is rolling resistance (tires, wheels, brakes, gears) and aerodynamics (air resistance). Some things can be done to improve rolling resistance and aerodynamics, but I am primarily concerned with weight at this stage of the project.

As my starting point, I wanted to know the weight of the car before conversion. I will then keep close track of the weight of all items removed and added during the conversion so that I will have a good estimate of the final weight of the converted vehicle. Of course the easiest way to increase performance of an Electric Vehicle is to make it as light as possible. If the performance of this car when finished is not satisfactory, I will start removing weight wherever I can.

Various books and manuals list the weight of a 1971 Duster 340 at 3200-3400 pounds. I was pleasantly surprised to learn that the car actually weighs 3080 pounds as it sits today. I was a little untrusting of that result so I drove a few miles to a different scale. The weight came out exactly the same.

I will be removing the internal combustion engine, mufflers & exhaust system, fuel tank, radiator, and a few other miscellaneous items including the back seat. The 3-speed manual transmission will remain, but not the clutch & flywheel. I roughly estimate that all of these items will total 1000 pounds.

I roughly estimate that I will be adding 2000 pounds back into the car. The electric motor is only about 140 pounds, but the 26 batteries (66 pounds each) will total a whopping 1716 pounds.

My goal is to keep the final weight under 4000 pounds (including driver). This is well within the maximum load that the car was designed to carry. Judging by the performance numbers that others have reported, I hope to attain a maximum speed of 65 mph and a range of 50 miles.