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Porsche Tesla Motor Swap

Alright, today on Repairs 101 this 2002 Porsche Boxster S electric conversion using a 2015 Tesla model S P85 motor and a 2015 Kia Soul battery, charger and battery management system. This episode of Repairs 101 is sponsored by Princess Auto.

Porsche Tesla Motor Swap

Hi, my name is Terry Moore. I’m a retired engineer and what I’m going to talk about is a Porsche Boxster which I have converted to an electric vehicle. This is a perfect conversion for a Tesla electric motor because everything fits in there very, very nicely. The batteries for this conversion came out of a 2015 Kia Soul with about 20,000 miles or 30,000 kilometres on it.

The battery pack – there are eight modules and the total voltage is around 400 volts. I’m using the existing Porsche radiators in the front of the car and I installed a Bosch water pump. This is the little Bosch water pump. And basically it takes all of the water that comes from the radiator. The cooled water goes through here and this is the discharge which goes all the way down to the motor. From the motor it goes back into the return line which goes all the way up into the frunk, and that is where the charger is and then from the charger, it goes into the radiator and then back out through here. The cooled water goes through the pump and it goes back into the motor – that is the cycle.

What I’ve got is a 6.6 kilowatt high voltage charging system that came out of the same Kia Soul where I got the batteries. This charging system can plug into any J17-72 plug in, which is what the standard is for most EV voltages.

Tesla P85 motor

The motor we are using for this conversion is a sport motor that came out of Tesla P85. So it is a high-performance motor, putting out under full voltage about 460 horsepower. With a voltage pack that is currently in the vehicle… It’s probably going to put out around 345 horsepower or around 300 kilowatts. It is a single-stage three phase motor with a single stage gear box with a ten to one reduction.

The motor basically bolts directly into the existing Porsche frame. And with one modified drive shaft on each side, it is a direct couple to the existing Porsche drive system. One of the more unique features about this conversion was that we had to install the Tesla motor backwards in the vehicle. When you run this Tesla motor backwards, you have to reverse the oil pump. So that the oil properly flows through to lubricate the gear box plus the rest of the components there.


The next thing we had to look at was the power steering to the vehicle. So what I did was I got an old Volvo S40 electric hydraulic pump. This is the vacuum pump. This is what basically provides the vacuum for the power braking system in the vehicle. Again it is a 12 volt system.

One of the more important components of an electric conversion is to put in DC/DC converter. And what that does… It takes the full voltage of the main battery, which in this case is the 400 volts. And converts it down to a usable 12 to 12 and a half volts.

Battery Management System

This is kind of the brains of the whole operation. This is called the BMS or the Battery Management System. And what it does is it monitors the battery when it is being charged to make sure that all the batteries are charged at the same rate but also monitors when the car is operating, how the batteries are discharged so that they are all are discharged at the same rate so you don’t have a battery which is at a much lower voltage than the other batteries. All of the orange cabling that you see here goes to each of the individual batteries and can measure the temperature as well as the current which is going to and from each battery.

Dash Cams from Cobra Electronics

One of the biggest things we needed to do for this build is basically to support the motor and the battery in the car. The battery pack itself weighs around 400 pounds. And the motor itself weighs is a little over 300 pounds. So we needed something to support 700 to 800 pounds.

body porsche tesla motor

What I found was a pre-built frame which was built for the Porsche Boxster. And it came from F1 Moto in the UK. It bolted directly into the Porsche frame and so far, it’s worked very very well.

porsche tesla boxter
Professional CB Radios from Cobra Electronics