Had wind gusts of close to 100kmhr one day, and the neighbours were looking very concerned for their safety so thought I had better take it down. During taking it down the whole cover just ripped in half, good stuff
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Oh damn, good judgement call on that one. Theres a good amount of youtube videos of wind carrying pools.
Just some thought processes about the conversion so we can keep this on track.
I’m not sure if I want to have this car go really fast or if I want to do that with another vehicle. I was looking at high performance gearboxes for FWD cars, and the options are few and far between. The Toyota e153 has been floated as the most capable OEM option, but used models can reach up to $2K. For aftermarket options the range can go from a couple thousand to tens of thousands of pounds (not dollarydoos). This made me realise that the power levels that I wanna reach eventually will not be attainable without a far more robust gearbox solution. I am considering having this vehicle just be ‘good enough’ and then buy another RWD vehicle down the line, but wanna make this lil thing go quick!
I figure the current box handles at least 50kw as the original ICE maxed out at 48kw. I have been looking for DC motors on alibaba that are around the 40kw continuous (EV motors can peak far higher for first few seconds of acceleration) but the options are few and far between. I also hate dealing with alibaba sellers as they are either unresponsive or won’t give me the options I’m asking for. I have also been looking at used EV motors such as the Nissan Leaf setup or some used DC motors but have struggled to find something I like.
Just last night I have discovered that my town has an EV club, which I assume is a bunch of old dudes that have too much time on their hands. I’m gonna head to their next meeting and see if maybe some of those people have sources for parts and stuff. Also will be nice to meet some people with this interest as its hard to find other like minded people.
If anyone has any questions or points to make then go for it!
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Anyone with a US address and experience shipping batteries wanna help me out? This place only ships to the US but the cells are so cheap it’s too good to pass up
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Wow. Thats a good deal. Almost a kwh for 65 bucks
Hey guys so development has grinded to a halt on this due to the fact that I lost my main job to the virus for a few months. Not to worry, this has given me time to look into other options besides my initial plan of just a basic DC motor. For a while now I have been watching a bloke named Damien Maguire on YouTube who has been making detailed and informative content about DIY EVs for years. In the last couple years he has started taking closed source electric solutions such as those from Tesla as well as the Toyota/Lexus hybrid systems and hacking them and developing open source hardware and software for controlling them.
This has led me to the Toyota Prius. Damien makes a control board for the Gen 3 inverter, which he sell for 300EUR (530AUD). I can go out and buy a used inverter today on eBay for $225 shipped. This inverter/converter system includes two inverters, which are limited to a max of 50kw normally, but have been tested at up to 600v and 350A for MG2 and 250A for MG1, which is a total of 360kw. For $225 dollarydoos this is an incredible deal. The package also includes a boost converter which can act as a battery charger, as well as a DC-DC converter for powering the accessories battery. This one package contains all of the electrical goodies that I would need, besides a motor.
The Prius inverter will obviously work best for the Prius electric motors. The Gen2 transaxle is slightly more powerful than Gen3, but the transaxle will work with the inverters no matter the version. There is two stators in the transaxle, one for starting the ICE, and another for running the car. In the case where there is no ICE, both can either be used to power the car or the smaller one (MG1) can be used to charge the battery, in conjunction with the inverter. One of these transmissions can be found on eBay for $250 shipped, and has a max power of 50kw and 400nm on MG2, not sure about MG1 as documentation is hard to find. That is a crazy low price for the power output and will work perfectly for the vehicle that I have here.
So the cost here will be $500 for Damien’s board, $220 for inverter, and $250 for transaxle. All I need is the batteries and I’m 95% there. I plan on slowly acquiring these pieces over time and figuring how they fit into the vehicle and begin making necessary modifications to the cars body such as an aluminum skid plate at the bottom of the engine bay to protect the precious electronics.
Speaking of batteries, here’s how YOU can help me:
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Chassis Electrics
For this conversion I want to keep it as stock as possible, with all original items inside the vehicle working as intended including the stock instrument cluster. What I also have planned is the addition of extra features, such as electric windows, central locking, and hacking in Bluetooth support to the stock tape deck. I also will need to add extra warning lights for various thing such as low pump pressure in the various water-cooling loops or a low battery voltage or something. To do all this extra stuff, I was thinking of designing my own circuit board that utilises a microcontroller to control the various inputs and outputs that I will be using here. I’ve never done anything like this before, but have done some basic stuff with Arduino and raspberry pi in the past. My question would be, is there a specific type of product I should be looking at to achieve what I what to achieve? Is there a solution with a large number of configurable digital and analog inputs and outputs? Any info that will help guide me will be awesome, especially when it comes to circuit design
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Cool thread man I have been reading through it and its really fun to see you take on this project. Good luck with the project and I will be looking forward to the updates in the future 
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Glad you’re interested! This is such a large project for me as I’m usually a pretty sloppy and cheap DIY guy but really looking forward to giving this a go. Hoping to have some updates about hardware I can share in the next few weeks
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P112 Prius Gen2 Transaxle
I present to you the P112 transaxle, the latest in hybrid vehicle technology, if it were the mid 2000s. In this 100kg package we have a bell housing, which is the interface which connects to the ICE; 2 electric AC motors, one that is 50kw and another that is around 30kw; as well as the necessary gear systems, electrical and mechanical interfaces. With some clever welding of part of the power split device, we can cause both MG1 and MG2 to spin at the same speed.
Those wanting to learn more about this transaxle should watch this video: https://youtu.be/ia6jJO3cuOY
The current implementation for the Damien Maguire control board for the inverter only allows use of MG2 for propelling the vehicle, and uses MG1 for charging. An earlier board version did in fact control both motors but this function has since been removed. I may custom order my own board of the older version so that I can gain use of both motors as that will mean a combined power of ~80kw and 500nm+.
The rotational maximum speed of MG2 is rated at 6500rpm. The original vehicles maximum allowed speed was 103mph and at this speed MG2 is running at ~5700rpm. MG1 is rated at 10000rpm which means I have a bit of headroom to work with, not to mention I’ll never get to 103mph ever on the roads. This gives me piece of mind knowing this hardware can work as hard as I need it to.
I believe this transaxle has an oil pump built into the end of the outer housing for MG2, which is also a 3phase AC motor. This has a connection directly into the inverter which means that cooling for this can be easily done. To simplify things I will probably just use a 12v pump as that will make things cheaper. This transaxle, along with the inverter, require cooling as there is very little thermal mass given to cooling. I will be ensuring to build a robust thermal solution once installed in the vehicle.
In the coming weeks I do plan on opening this thing up and giving it a clean and making sure everything inside is as should be. There is also an AC compressor that I need to remove and decide if I want to use it. There is currently a small effort trying to reverse engineer this specific compressor for DIY use.
Here are a few photos, more coming in days to come:
If anyone has any questions ask away. Inverter is also on its way. That writeup should be more detailed regarding the underlying tech of running these motors
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Bonus: here is Damian with a running configuration that uses the exact hardware I plan on using, minus a slightly different variant of inverter
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Do you plan on using MG1 to get above that 6500rpm limit of MG2? Or are you just going to leave well enough alone with a 103mph top speed? 
I ask because as I recall, there have been a couple discussions here about using motors with different kV ratings (not sure if thats the case with these two motors, but the principal might still apply) where folks concluded that the back-emf from the lower-limit motor would outweigh the work that the higher-limit motor is putting out. Not to mention potentially confusing your motor controllers. Not sure how much or if any of that is applicable to your hardware though. 
Either way Im super excited to see this project moving forward!
Any progress in the battery department? Still planning on using the SPIM packs?
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Awesome build man, don’t know how I missed it before, being that this is also a dream of mine one day, I will be following closely
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So I don’t plan on going above the 103mph limit as this won’t be used at any drag strips or anything. This harware is interesting in that the controller simply gets given a torque command from the pedal then it sends that torque to the motors. Back EMF isn’t an issue I believe because these are 3 phase AC motors, correct me if wrong.
I am also still looking at the SPIM cells, @BluPenguin is getting a quote done on sending 72 cells to me. This hardware I’m using is cool because it will accept anywhere from 140-350+ volts so I can use a wide variety of different pack sizes and configurations. I will probably buy more cells in the future too as this project moves on and power requirements change
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Glad you are enjoying it! I hope that my particular DIY method is interesting as it’s easily one of the cheapest options for a DIY EV, its just super hacky in this early stage
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Hacky is fine as long as it doesn’t catch fire
What I really wanted to do is to convert motorcycle one day, but make it have enough highway range to travel, and capable of fast charging, but given that I can count the number of charge stations for the whole country in the hands is a bit of a pipe dream for now
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You’d be surprised how much range you can cram into a motorcycle if you’re creative. I’ve also seen people charging at like 5kw on a bike, but there are DIY solutions for faster charging (open source control boards for tesla chargers) if you have the space for it
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I am really looking forward to the documentation of how you actually mount all the parts and wire it up! The fabrication work is what has really held me back from looking into EV conversions more. (That and cost, of course).
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Honestly I’m looking forward to that too because I’ve got no idea right now 
I need to start making measurements of the current transmission and figure out things like whether I need to get new shafts and whether the current mounts will be even remotely useful
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