DAVID HEACOCK's 1985 AVANTI EV CONVERSION (IN PROCESS)
After separating the frame from the body I starting looking closer at the condition of the frame and suspension components. I decided to rebuild the front suspension even though the design is basically over 40 years old. On the plus side this suspension was designed to handle a vehicle with a GVWR of almost 4500 pounds with a V8 engine over the front suspension. Therefore I felt the front suspension would be capable of handling the weight of the batteries I was going to install in the engine compartment.
The following picture shows the original condition of the front suspension and the frame. I wasn't too excided about working with the coil springs but decided the more I learned about the suspension the better feel I would have for future modifications and maintenance needs. Removing the suspension would also give me the opportunity to clean and repair the frame.
After several months of working on the suspension and learning more than I ever thought I would, the front suspension was rebuilt and installed. I was finally able to install the new low rolling resistance tires which could be pumped up to 51 pounds. My 85 Avanti had power steering but I had heard the original Avanti did not. I was hoping that by using the low rolling resistance tires and balancing the weight distribution I could eliminate the need for the power steering and the corresponding weight. The following picture shows the rebuilt front suspension.
The original drive train for my car included an automatic transmission. Therefore I started looking at possible manual transmissions I could use to replace the automatic. Somewhere along the line I was talking to my brother, who suggested using a Harley Davidson motorcycle transmission and eliminating the drive shaft. At first this sounded a little crazy but we decided to explore the concept because I could eliminate the drive shaft and the heavy weight of a normal transmission. This idea also would provide a lot of options for the future with respect to drive train modifications by simply changing sprockets. As it turns out there are kits made to actually shift the transmission electronically so the shifting linkage could be eliminated. The original concept was to simply drive the original Avanti rear end with a chain drive from the Harley transmission. The following picture shows the original rear end as a fixed axle with the rear end moving independently from the frame.
The original idea also had the 9-inch Advanced DC motor placed behind the rear seat where the gas tank had been located. The picture below shows the empty area behind the rear seat where the 19-gallon gas tank had been removed. This also seemed like a good idea because the motor would be protected inside the car and would help distribute the weight toward the back of the car as part of balancing the weight on both axles.
As the idea of using the Harley transmission progressed I invited the owner of a local shop over to talk about how the motor and transmission could be installed. Shortly after starting to discuss our idea it was pointed out that we probably had a fatal flaw in our thinking. With the motor and transmission attached to the frame and the rear end moving up and down independently from the frame, there was a high probability that every time the car went over a bump the chain might come off. So the direction of the project took another turn. It was decided a rear end with independent suspension would be needed. After looking at Ford, Jaguar and Corvette suspensions it was decided a Corvette rear end would be installed. Most of the components are aluminum and again I was hoping for a weight reduction. The modification should also provide for a better ride so everything seemed positive. A 1984 Corvette rear end was found at a local Corvette shop and is shown in the following pictures before it was cleaned and modified.
In order to get the Corvette rear end under the Avanti the half shafts and tie rods needed to be shortened. I found a shop in southern California that actually made a kit for installing the rear end but the kit was not specific to the Avanti so further changes would be necessary. The kit and the Corvette rear end allows for use of a coil over spring arrangement, which can be tailored for the final weight of the completed electric vehicle.
The various components of the Corvette rear end were disassembled and cleaned. The half shafts were taken to a shop in Sacramento where they were shortened and balanced along with the installation of new U joints. It turns out the rims on the car were really Ford rims from a Lincoln. Since the bolt pattern for a Corvette and a Ford are different, I had to find a shop that could re-drill the new Corvette rotors and the original hubs. At first this sounded simple but the problem was the bearings in the Corvette hubs are sealed and any needed welding to change the bolt pattern of the hubs could have damaged the bearings. However, another shop in Sacramento was able to modify the rotors and hubs so the Ford rims could be mounted. The following picture shows the assembled half shafts, knuckles, hubs, rotors and new brakes.
The center section of the Corvette rear end was cleaned, completely drained of oil and visually inspected. The gears appeared to be in good condition so the unit was reassembled after a crack in the web structure of the "wing" portion of the unit was welded. The following picture shows the completed center section.
After an extended period of time, during which I cleaned and repaired the frame as much as possible, the rear end components and the frame were taken to a local shop for installation. This turned out to be a much bigger project than originally expected. The following pictures show the rear end temporarily positioned in the Avanti frame.