Tesla Technology

This page is dedicated to the Tesla technology borrowed from the Model S 70D that is being transplanted into the DeLorean DMC-12.

Moving technology from one car to another is challenging enough, but moving technology from a 2015 electric drive car to a 1981 car is really challenging. Thankfully some things are consistent, such as the use of 12 volts for ancillary electronics (non-traction), and the use of hydraulic pressure to apply the brakes.

System Description Gallery
Drive Unit The Tesla drive unit is comprised of an electric motor, a transmission, and a motor controller/inverter.
The drive unit (using the inverter) converts DC power from the battery pack to AC power for the motor. The unit communicates with and takes instruction from the Model S through CANbus.Electric motors do not have a narrow ‘torque band’ like a combustion engine, so the transmission requires only one gear. Reverse is achieved by reversing the spin direction of the motor.The Model S70D rear motor weighs approximately 210 lbs and measures roughly 22 in wide (motor to inverter), trans final gear housing is 8″ wide (shaft port to port), 13in tall, 25in front to back including the unit mount on front and back.
Tesla 259HP Drive Unit
Drive Unit from a Model 2 70D
iBooster Brake Master The iBooster made by Bosch is a vacuum-less brake assist. The iBooster assists the driver pressing the brake pedal with an electric motor as there is no combustion engine to provide vacuum. The power transfer from the master brake cylinder to the wheels uses hydraulic fluid, consistent with non-EV cars.
The iBooster is used on autopilot Model S cars, as the unit can be instructed, via CANbus, to press the brake independently of the driver.The iBooster only consumes power when braking is required. Prior EV conversions would use an electric vacuum pump and a vacuum reservoir to provide a standard brake booster with a vacuum supply. Vacuum pumps can make noise or cause a start-up delay while sufficient vacuum pressure is supplied.
Bosch Ibooster
Bosch iBooster
Electric AC Compressor The Tesla AC compressor is fully electric, integrating both an efficient scroll compressor and and an electric motor. Other AC compressors require to be belt driven from the motor or engine. This compressor takes electric power from the battery pack.
The unit does not require a clutch, as the electric motor can be switched on and off as desired.

Note: I’ve switched to the AC compressor out of the 2014 Tesla Model S so that it can be easily controlled.  The 2015 compressor is controlled with CANbus code and currently the control codes are unavailable.  The 2014 compressor is controlled using PWM.

Tesla AC Compressor
Tesla electric AC compressor
DC-DC Converter  The DC-DC converter takes in 400v battery pack power and provides as output 12v (actually 12.6v) to power common automotive devices.  DC-DC-Converter
Coolant Heater The coolant heater uses high voltage power to raise the coolant temperature.  Electric-Heater
Coolant Chiller The coolant chiller is a heat exchanger between the AC R-134a system and the coolant system.  The AC compressor provides compresser R-134a refrigerant to the unit, it goes through an expansion valve to lower the pressure and produce a cooling effect.  The coolant loops also run through the chiller and thus the unit reduces the temperature of the coolant.

I will need to add a solenoid valve to the coolant line to be able to activate and deactivate the chiller as necessary.

Coolant Pumps and Valves The coolant pumps and valves are used by the computer to manage the temparture of the main components of the car (drive unit, inverter, dc-dc converter, charger, battery) and also provide heat or cooling as necessary to the passenger cabin. The computer manages the heating/cooling to keep the operating conditions of the components as close to their optimal temperature as possible.  Diverter-Valve
Steering Wheel and Column  The steering wheel and column provide the standard driving signals (indicators, wipers, lights) and also steering wheel adjustment. Additionally the steering wheel has computer controls on the left and right hand sides. These buttons and scroll wheels allow the driver to interface with the computer while maintaining a hold on the steering wheel.

The controls also include the PNDR selector stalk – which the DeLorean does not have as it has a manual transmission.

High Voltage Distribution Box The high voltage distribution box distributes battery voltage to the high voltage devices, i.e. AC compressor, cabin heater, coolant heater, DC-DC converter. High-Voltage-Junction-Box
High Voltage Junction Box The high voltage junction box sits under the back seat of the Tesla Model S and pairs up with the charger (or chargers if dual chargers).  It moderates the flow of power to and from the battery and charger, and from the charging and supercharging port.

I have deconstructed (not to be reconstructed) the high voltage junction box.  I’m going to rebuild the junction box into a new switch box to house contactors and a pre-charger circuit.  The contactors, copper bus bars and fuses were recovered from the Tesla box.

 High Voltage Juction Box
PTC Heater The Positive Temperature Coefficient (PTC) heater is a resistor that increases its resistance as it heats up. This limits the current it can pull and regulates heat production.  The PTC heater runs on 400v power from the high-voltage distribution box.

The heater is used exclusively for cabin heating, so it is located inside the airbox inside the passenger cabin air conditioning system.

The 2015 PTC heater appears to be CANbus controlled. As yet I have not decoded or gained access to the control codes.  There are many PTC options available (not CANbus controlled) that may also fit better in the DeLorean airbox.  In addition seat heaters are an energy efficient option which has been successfully implemented in the DeLorean by others.

 PTC Heater Model S