Good technical info here:
http://www.houseofjapan.com/auto-moto/mitsubishi-at-2012-pikes-peak-international-hill-climb
While the i-MiEV Evolution is a prototype racing car,
numerous components and systems are carried over from the street-legal production car. These include the electric motor, lithium-ion batteries, MCU, communication wiring for controls, and various instrumental panel gauge. Utilizing as many stock components and systems from the production 2012 Mitsubishi i-MiEV is a critical design element to the i-MiEV Evolution because Mitsubishi Motors engineers want to identify performance limitations of these production parts under the strenuous conditions of the Pikes Peak event so that they may work with their supplier partners (many of whom have sent key personnel to the Pikes Peak event) to gather and share engineering feedback.
Drivetrain
The i-MiEV Evolution features three electric motors, one front motor and two rear motors. These electric motors are identical to those found in the production Mitsubishi i-MiEV,
but they have received a software upgrade to increase the motor's power output from 49 kW (65.7 horsepower) to a more potent 80 kW (107.3 horsepower).
Likewise, the individual lithium-ion battery cells found in the production Mitsubishi i-MiEV have been used for energy storage in the i-MiEV Evolution, just in a larger quantity. While the road going version of the vehicle's main battery pack stores a total of 16 kWh, the Pikes Peak car's energy storage is rated at 35 kWh – more than twice as large as that of the street car.
Cooling of the lithium-ion batteries is accomplished by a ventilation fan (per
Pikes Peak regulations) while the electric motors are cooled in a nearly identical manner to that of the electric motor in the production Mitsubishi i-MiEV, using a similar water-cooled system.
The i-MiEV Evolution is
charged exclusively by DC quick-charging; Mitsubishi will have a specially-prepared truck equipped with a CHAdeMO DC quick-charging device at the Pikes Peak event.
Electric Motor Characteristics
By reworking the inverter control settings and increasing the
maximum rpm to 11,000, engineers were able to select a shorter gear ratio to gain an advantage in acceleration speed.
A key characteristic of these changes is that the electric motors are able to maintain maximum torque output in a lower rpm range for better lower and mid-range acceleration that better suits the uphill climb of the roads that wind their way along the Pikes Peak course, with the added benefit of minimizing the power output loss at higher rpm levels (when compared to the stock production i-MiEV).
Of note,
both the electric motor and its accompanying inverter hardware are identical to those found on the street-legal 2012 Mitsubishi i-MiEV.
High Voltage System Configuration
Using the identical individual lithium-ion battery cells from the 2012 Mitsubishi i-MiEV production vehicle, a higher voltage and capacity was achieved by connecting two cells in parallel, 96 cell pairs in series.
Each electric motor will receive information from its own controller to generate/modify torque output. Of note, the two electric motors placed at the rear of the vehicle are directly connected and are synchronous, while the single front motor feeds power to the
front wheels through the production-spec transmission found in the 2012 Mitsubishi i-MiEV production car.
Advanced New Mitsubishi All-Wheel Control (AWC) All-Wheel Drive
The one front/two rear electric motor layout was selected to provide a 1:2 front-to-rear ratio of power application. By doing so, Mitsubishi engineers were able to achieve the tractability and stability benefits of all-wheel drive while allowing the car to have handling characteristics more akin to that of a rear-wheel drive vehicle – the best of both worlds in terms of ideal vehicle dynamics.
Depending upon the condition of the road surface at Pikes Peak, the team will be able to adjust the front/rear power application level to maximize the vehicle's dynamic performance.
Data gathered from the new All-Wheel Control (AWC) all-wheel drive system used on the i-MiEV Evolution will be used to help develop a highly advanced AWC system that will be available on the next-generation plug-in hybrid electric vehicle (PHEV) when it arrives in North America in the near future.