So why convert a car that has a perfectly good gas engine to electric power? Well I enjoy building things, and the more the project has to do with engineering the more enjoyable it seems to be for me. I have in the past built an airplane, a number of racecars and various remodel project around the house. My day job has me build and develop all kinds of thing, so the idea of an electric car seemed to be a perfect project. Not paying a oil company for gasoline is a bonus.
So choosing a car. I started thinking about the type of car I would like to drive. No sense in completing this type of project only to have a car that is not enjoyable to drive. Two seat convertible sports cars it is then.
The list of potential candidates included;
Porsche Boxster
Mazda Miata
Honda S2000
Audi TT
Pontiac Solstice
Mini
BMW Z4
Mercedes SLK
Corvette
Porsche 911
and a few others...
After a number of test drives and looking at specification, including the weight of the car, room for batteries, the systems in the car and so on, I choose the BMW Z4. During the winter of 2013 a not so fine example come on the market. It was one of the coldest day we had in a long time and I when to look at the car. December seemed like a to time to be a buyer of a convertible. It was at a price that would be very hard to bet. So I returned home with the car to start the project. The fantastic deal turned into only being a reasonable deal as there where many, many items broken on the car, including;
- Passenger window switch
- Replaced steering wheel, gear shift knob, and hand brake leather
- Repaired driver door interior card
- Recovered seats and added seat heaters
- Replaced third brake light lens
- Replace both head lights
- Replaced front bumper
- Replace left front inner fender well
- Replace under engine tray
- Replaced oil pressure switch
- Repaired hood latch
- Replaced convertible top hydraulic motor
- Repaired electrical limit switch wiring for convertible top
- Replaced water pump and thermostat
- Added aux input to stereo
- Outside air temperature sensor
Well I suppose that the cars is fairly well shaken out now and the project can get underway.
So what about the plan. By the time I got the car working it was well into summer here and it didn't make sense to but the car in the garage during the nice driving weather while the conversion took place, so the plan to convert electric power was put on hold until the fall (2014).
But the project continues. I started finding sources for all the items that I would need. I settled on a conversion that will use a three phase AC motor, as opposed to a DC motor. The AC motor seems to be the choice of the manufactures that are being to make electric cars. So it would be goo enough for me too. It also offers less maintenance and more control options that my perception that the DC motors have available.
The electric motor was purchased from www.evtv.me . It is a AC three phase unit manufactured by Seimens. Originally made for the Azure Dynamic Ford Transit Connect van. Azure Dynamic took the van from Ford without a gasoline engine and install this electric motor. But as sales did not met expectations Azure Dynamics went bankrupt. The is where EVTV stepped in purchase the remaining inventory.
