VIEWS: 140 PAGES: 2 POSTED ON: 8/3/2011
May 30, 2009 lmu 1987 Toyota MR2 Mk1 Electric Conversion Project Car PEVA Owner: Lee Underkofler My electric vehicle (EV) project is the conversion of a MR2 Mk1 Toyota sports car to electric drive. Two pictures of the vehicle purchased to be converted are shown. It is a small two seat car that is light weight (~2250 lbs) and has a published aerodynamic drag figure (Cd) of 0.31– 0.34 and CdA of 5.80. The MR2 is a mid-engine rear wheel drive configuration which I believe is an ideal choice for electric power conversion. I looked for a couple of years to find this particular MR2 which has a „targa top‟ and no energy wasting power steering, power windows, power mirrors and such. The gas motor had a loud rod bearing “knock” which allowed me to purchase it for an economical(?) price. I was able to obtain a three-phase AC motor and drive unit from a General Motors 1997 S-10EV pickup for this conversion. Two photos of this motor and drive are shown. Photo 1 is a right side/rear view of the 85 kW (114 hp) induction motor which is attached to the reduction drive unit shown the lower right (drive mostly hidden). This motor is liquid cooled; the green caps cover the connections for the coolant. The orange cable and connector at the top of the motor is the input for the high voltage AC. The black object on the rear of the motor is an „encoder‟ that originates two low level analog AC signals electrically 90 degrees apart to allow monitoring the speed and direction of the motor. *[As I write this, the encoder from my S-10EV motor has been installed on an EV-1 motor that is on it‟s way to England to run in the „Isle of Man Clean Air‟ motorcycle race June 12, 2009.] Photo 2, taken from the left side of the motor, results in a better perspective of the gear reduction and differential drive unit into which the electric motor is bolted. It also clearly shows the high voltage cable end connector that plugs into the S-10EV inverter. The plan is to mount the motor and gear reduction/differential unit in the place the original transaxle occupied. The CV-joints on the half shafts driving the rear wheels will mate directly to output shafts on the left and right sides of the drive unit. There will be no transmission or clutch; only a single speed gear reduction from the motor to the axles. The motor and the attached gear box weighs ~150 lbs; considerably less than the original gas motor and transaxle! Of course, battery weight will more than make up for the difference… My current effort on the MR2 project is determining the approach I want to take for the motor inverter/controller. At the moment I am considering three possible ways to proceed: May 30, 2009 lmu 1) Do a “lobotomy” on the original large and heavy S-10EV pickup inverter replacing the logic and control circuitry with a much simpler „brain‟ for motor control only… 2) Purchase a custom inverter offered to me by the team that built the EV-1 powered electric „Isle of Man Clean Air‟ race motorcycle… 3) Further investigate the possible use and purchase of a MES-DEA vector control AC motor drive… The MR2 chassis will require much work and repair. At the least, it needs ball joints front and rear, shocks, brakes, bearings, new front bumper, possibly new springs, and ?? Mounts for the motor and reduction drive will have to be fabricated and welded into place. Likewise, the inverter will need to be mounted and cooling systems for both the motor and inverter will require design and fabrication. When a decision is made on batteries, the battery containers will also require design and fabrication, etc., etc. To be continued….the progression of a project in process.
Pages to are hidden for
"1987 Toyota MR2 Mk1 Electric Conversion Project Car"Please download to view full document