Friday, August 22, 2008

I Got the Power!

Even though my motor is not due for another 2 or 3 weeks, I went ahead and got the traction batteries yesterday. I could have gotten these last, but having them on hand now will help me with designing & building the battery racks and battery connecting hardware. I picked all 1700 pounds of them up locally. As I was driving home with my truck's front wheels in the air, I could feel the effects of all of that weight on the handling of the truck. I was afraid to get on the freeway so I drove most of the way home on surface streets. I was seriously wondering how the duster would drive with all of that weight. Scary!

Saturday, August 16, 2008

Past the Point of No Return

Finally, after a very long wait of 6 weeks, some of the components that I've ordered finally began arriving this week. This inspired me to actually begin work on the car.

I removed the gas tank and filler pipe with its associated venting and tubing. Also, after a little bracket cutting I was able to remove the entire exhaust system in one piece. All of these items will eventually be transferred to my 1970 Duster project (to be started sometime later this century).

Next, and most painful, was cutting out the trunk floor to prepare for installation of some of the batteries. I will be building a rack to hold 12 of the 26 "traction" batteries between the rear frame rails. Eight of these batteries will be installed flush with the floor to save trunk space. This will allow enough room for a small charge-supplementing generator that I may install later.

I also plan to use this opportunity to finish my paint job in and around the trunk. This may delay the completion of this project, but it desperately needs to be done and I just can't leave it looking like it does now.

Sunday, August 3, 2008

Step One: Weights & Measures (continued)

With the weight calculations out of the way, on to the measurements. For comparison purposes I measured & recorded the ground clearance to the top-center of each wheel well lip. Fortunately the Duster has lots of wheel clearance all the way around, so adding a thousand pounds should not cause tire clearance issues. The Duster also has torsion bar adjusters to easily change the height of the front of the car.

I also carefully measured & recorded the position of the transmission. It will need to be reinstalled in exactly the same position to maintain the correct driveline angle.

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.