Project P9311

Project P9311 officially began in November of 1993 and would follow Mike Brown's conversion philosophy. The internal combustion engine would be replaced with an electric motor. A traction battery of 96 volts or more would be installed using lead acid batteries. A battery charger would be installed on board so that the car could be plugged into the wall for recharging. A DC-to-DC converter would be used to convert the traction battery high voltage to 12 volts to operate the car's accessories. Gauges would be installed to monitor the battery state of charge and current drain.

Before starting work, I had to decide what type of batteries to use, where to put them and how many I could squeeze into the car. I chose the U. S. Battery model 1450, a 12 volt, 145 amp-hour, deep cycle lead acid battery. I figured I could fit eight of the batteries (96 volts) in the Porsche's limited space: four in the front where the fuel tank was located and four over the rear seats. For safety reasons, I chose to use plywood battery boxes, glued, screwed and banded together and clamped into racks with holddowns. This would help contain the batteries in case of a crash.

Project P9311 would consist of the following main tasks (taken loosely from the chapters of Mike Brown's Convert It book):

  • Remove the internal combustion components (e.g., engine, gas tank, etc.)
  • Install the electric motor and transmission adapter supplied in the kit
  • Design, build and install the battery boxes and racks (without batteries)
  • Install the electric vehicle components (e.g. motor controller, battery charger, etc.)
  • Install the wiring and test
  • Install the batteries and perform final tests
  • Tweak the suspension system to handle the new, heavier vehicle weight

Each of these main tasks consists of numerous subtasks. Also, the car is being refurbished as the conversion proceeds to ameliorate the effects of 15+ years on the road. A big part of the effort has been spent locating raw materials, special parts, tools and people to do the things that I couldn't. It would have helped to have a broad automotive experience and live near a wrecking yard.

Fundamental Principle
No part, no component or any portion of the car shall be made accessible and easy to work on.

The details of the work accomplished can be found in my diary. If you read the diary, be aware of my ignorance in mechanical design and in the practical application of the arts and crafts of automobile work. I had no idea what I was doing most of the time! There are a few pictures available, too.

Copyright 1996-98 D. M. Brockman - March 15, 1999