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Discussion Starter #1 (Edited)
I have always been a fan of electric cars and want to plan a future build. I’m still in the research stage and deciding what it’d take to pull it off. I’m finding it hard because there seems to be a lot of conflicting info on the forum and quickly outdated.

My donar car would be a 2004-2010 Bmw 5 series.

I’m hoping to achieve 100 miles range with 90mph minimum speed.

Pretty sure it’s more reasonable to buy second hand evs but I’ve always liked the feeling of building something and calling it my own.

Based on the above, what path would you recommend?

Budget is around $6k excluding price of the car but hoping to do it cheaper if possible.

What’s the most cost efficient or best way to go about it?

Not my car but here’s a visual IMG_4119.jpg
 

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Afraid you will need to temper your expectations or increase your budget...

A 5-series isn't a light car, and to go 100 miles you'll need a fair quantity of batteries, especially at higher speeds. The energy use increases a lot at higher speeds as the wind and road resistance.

You need to think when budgeting about Batteries, BMS, Motor & Controller, Fabrication costs for mounting and mating to the transmission, fabrication costs for battery boxes, cabling, modifications to the controls, instrumentation, Heating/AC, Power Steering etc.

Additionally, since the car is a BMW and its quite recent, expect technical resistance in your conversion - some of the cars systems may not work on their own unless you're willing to spoof certain messages around the car's CAN bus.

If you want to retain power steering, AC, Heating, etc you will also need to budget as such - an electric AC compressor and power steering pump will need to be fitted or the existing ones adapted to be electric powered as opposed to belt driven from the engine. Heating as well - as you've no major source of heat from an electric Drivetrain you would need to install an electric heater, which will sap range from the battery in use.

Take a look at other conversions similar to yours in specification and that may give you a closer idea of what it might cost. I'm doing a 70mile range conversion of a cheap MG sports car and I expect it to cost 6-8k excluding the car (and it may yet overrun this).
 

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Discussion Starter #3 (Edited)
Afraid you will need to temper your expectations or increase your budget...

A 5-series isn't a light car, and to go 100 miles you'll need a fair quantity of batteries, especially at higher speeds. The energy use increases a lot at higher speeds as the wind and road resistance.

You need to think when budgeting about Batteries, BMS, Motor & Controller, Fabrication costs for mounting and mating to the transmission, fabrication costs for battery boxes, cabling, modifications to the controls, instrumentation, Heating/AC, Power Steering etc.

Additionally, since the car is a BMW and its quite recent, expect technical resistance in your conversion - some of the cars systems may not work on their own unless you're willing to spoof certain messages around the car's CAN bus.

If you want to retain power steering, AC, Heating, etc you will also need to budget as such - an electric AC compressor and power steering pump will need to be fitted or the existing ones adapted to be electric powered as opposed to belt driven from the engine. Heating as well - as you've no major source of heat from an electric Drivetrain you would need to install an electric heater, which will sap range from the battery in use.

Take a look at other conversions similar to yours in specification and that may give you a closer idea of what it might cost. I'm doing a 70mile range conversion of a cheap MG sports car and I expect it to cost 6-8k excluding the car (and it may yet overrun this).


Typed a long reply but it seems it didn’t post. If all else fails I can just go with the e39 since I daily one now and more info is available online.

Also, Couldn’t the cost be reduced if we source a parts car(Nissan leaf etc.) and use Damien Maguires controllers? I’m willing to spend extra, as long as I can get a reasonable range since I plan on keeping the car. I was thinking about using 2 Chevy volt batteries. Seen them for about $1500 each so not too bad, I think I may end up going the open source controller route to save.
 

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Go older than a e39, they still have a can bus. If you go back to e36 you have no can bus. Some super tech heads can fake the can bus and good on them but for me it looks like tour de headache. Theres nothing off the shelf, it seems to require buying tester equipment sampling the can bus, working out what signals do what then cloning those signals. If someone could sell a module made for doing this fakery out of the box that would be cool but there isnt that I am aware of.
 

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Go older than a e39, they still have a can bus. If you go back to e36 you have no can bus.
An E36 is a 3-Series, not a 5-Series like the E60 and E39. The 5-Series of that era (early 90's) - presumably without extensive use of CAN - would be the E34.

The rear suspensions change between generations, which could be important if considering the installation of a salvaged EV drive unit in place of the stock final drive (differential).
 

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Discussion Starter #6
Go older than a e39, they still have a can bus. If you go back to e36 you have no can bus. Some super tech heads can fake the can bus and good on them but for me it looks like tour de headache. Theres nothing off the shelf, it seems to require buying tester equipment sampling the can bus, working out what signals do what then cloning those signals. If someone could sell a module made for doing this fakery out of the box that would be cool but there isnt that I am aware of.

Yup. The CAN stuff isnt too scary for me. I found details of the E60 can online and have experience with Arduino and programming so it's doable for me. I do plan on faking the Canbus.

An E36 is a 3-Series, not a 5-Series like the E60 and E39. The 5-Series of that era (early 90's) - presumably without extensive use of CAN - would be the E34.



The rear suspensions change between generations, which could be important if considering the installation of a salvaged EV drive unit in place of the stock final drive (differential).

Yup. Im kinda looking for something modern so I chose the E60. Going back to pre-e39 cars then I'd be dealing with Rust issues

What you've described is my plan exactly. I plan on using the leaf motor in place of the diff. The E60 subframe looks big enough to allow me to bolt the motor in place of the diff without having to modify the chassis.

Doing this will allow me to use the transmission tunnel etc as extra space for batteries (Chevy volt) since I won't be needing the driveshaft or transmission. I plan on using two volt batteries that would give me around 60 miles of range.


Sent from my iPhone using Tapatalk
 

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I plan on using the leaf motor in place of the diff. The E60 subframe looks big enough to allow me to bolt the motor in place of the diff without having to modify the chassis.
Excellent if you can do it. In all of the projects in this forum, I have yet to see one able to mount any production EV drive unit in a RWD subframe without modification to at least the subframe. In his E31 850, Damien gave up and replaced the stock suspension (the same "integral link" design as the E60) with an old semi-trailing arm system from an E34 (with a modified E34 subframe plus a custom subframe to brace the modified suspension subframe and support the drive unit), but that was with a Tesla drive unit; Tesla places the motor behind the axle line, in contrast to the Leaf motor which is ahead of the axle line. It appears from a couple of projects that even a Tesla drive unit can fit between the stock suspension arms of a C5/6/7 Corvette, but only with a custom frame. CanadaLT28 is putting Leaf drive units in both front and back of a truck with stock VW T4 suspensions, but with modified (front) and custom (rear) subframes (VW LT doka with Nissan leaf). Other projects have either a Tesla in a semi-trailing arm suspension, or various drive units in customized suspensions.

Trivia: the Tesla Model S/X rear suspension is the same design (called some variation of "integral link" by the other manufacturers using it) as most 21st century BMWs; the Tesla Model 3 rear suspension is the same independent 5-link design (pioneered by Mercedes in the W201) as the E8x 3-Series (and E9x 1-Series). It's almost as if Tesla just copied their target competitors...
 

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Discussion Starter #9
Go older than a e39, they still have a can bus. If you go back to e36 you have no can bus. Some super tech heads can fake the can bus and good on them but for me it looks like tour de headache. Theres nothing off the shelf, it seems to require buying tester equipment sampling the can bus, working out what signals do what then cloning those signals. If someone could sell a module made for doing this fakery out of the box that would be cool but there isnt that I am aware of.

After reading your reply, I decided to get some equipment and try it myself to see how far I can get.
I used a Teensy 4.0 with triple CAN which seems to be an Arduino based board for $50 and bought a cluster from an 06 BMW 530i.



I spent the day yesterday tinkering and got it to work. I have a programming background but have never used C so it took some time to understand (all day lol). I figured out how to read, reverse engineer and send CAN messages which should be handy when using other OEM components and help me save a few hundred or thousands.

I don't have a car to sniff codes from so right now all I can do to test is hooking it up to 12V and seeing what it spits out. I did end up finding a list of CAN information for the e60 and got some to work but it's difficult in some parts because they have to be sent at specific intervals since the car sends Some code at 10ms,100ms and 200ms or they won't work.

That is an old picture but so far I've managed to get the lights to power on, get the RPM working, Trip calculator and Speedometer working by sending code via the Canbus. I also found the signals needed to start the car etc. The e60 uses the same CAN IDs as the e90 and I think the e85. All I have left to do is remove the error lights and get the fuel gauge to work so I can read my battery voltage when needed. That way I won't have to spend money on an aftermarket cluster.

I found a leaf motor, transmission and Canbus controller for $1200 total. The DC converter and Chargers I was looking at was about $500 total, so I might be able to do it on a budget with the battery being the most expensive component.

I have limited experience with welding but have experience using CAD To design (have a 3D printer) so I should be able to model parts and have them made by a shop to bolt in.

It's good to see my random skills being useful. Hopefully I can figure the rest out tomorrow.
 
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