EV Conversion for a Mk3 Coupe

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This ones going to be a bit of a slow burner as I need to get the convertible done first - which is almost there.

The project aim here is to convert my mk3 coupe into an EV using some Mitsubishi bits. Its already been done a couple or so times with minis so I am not breaking new ground here. Albeit probably first time for a mk3 coupe as far as I know.

Heres an example in a mini although there are others:
https://www.youtube.com/watch?v=rD71bMxrmD4&t=84s

Using the following components from a Mitsubishi PHEV Outlander mk3 from 2012/2020 models:

- https://openinverter.org/wiki/ZombieVerter_VCU to control the system
- Mitsubishi outlander mk3 Rear drive unit - this incorporates the motor and gearbox/diff into one unit. These arevgood enough to make 94hp (70Kw) so pretty bang on the money for the power I am after.
- Mitsubishi outlander mk3 rear drive shafts and inner CV joints. Will mate these to a set of metro driveshafts and outer VC joints. Probably tubed and welded to begin with before having some made up.
- Mitsubishi outlander mk3 rear Voltage Converter Inverter
- Mitsubishi outlander mk3 battery charging cable (including charge socket) - caveat this for type 1 so needs an adapter for type2 AC charging at home.
- Mitsubishi outlander mk3 dcdc converter/charger. Convert HV to 12v to run ancillaries.
- Mitsubishi outlander mk3 coolant heater.
- Wiring source from donor cars as much as possible
- Batteries TBD (the outlander has a 12kw battery which is ok for town range but need to look at alternatives for a longer range. It would need disassembly and repacking anyway.) Plenty of space on the MK3 Coupe to put batteries in the fuel tank compartment and in the back.

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Mitsubishi Outlander PHEV rear drivetrain came today so I offered it up to a spare NOS metro A series engined subframe I had in stock to see if it fits. I think thats a YES, looking at these images. Even the driveshaft angle is the same (or maybe even better actually as the offset is less than the OEM ICE motor):











And a comparison to swindons ev mini kit

[madmax83]

AWESOME project. I watch with intrigue.

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AWESOME project. I watch with intrigue.

Thank you. Quite surprised how easy it looks like it will fit. Building up a wooden frame with castor wheels so I can mock it all up with rollbar and top and bottom arms and swivel hubs and offer the driveshaft up then get some plate and get the plasma cutter and welder working to make a sub cradle. I bought some new drive shafts so I can chop them up and bolt to some existing metro shafts I have.

One of the things I have learned is that DVLA dont like you modifying the subframe with drilling extra holes and plates, so will have to make a subcradle which will bolt (or clamp) to existing subframe. In that way I wont be modifying the monocoque or subframes.

Here is another couple of links to other mini conversions in various states:

Electric classic Mini
https://www.youtube.com/watch?v=sjd1K0CAMvY

Opto mini
https://www.youtube.com/watch?v=-hoWXlt898A

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Batteries.

Will see but starting to look like I will go down the BMW sp41 hybrid battery pack route with the batteries dismantled from the pack and redistributed in a fabricated metal box to fit inside the rear hatch compartment/rear seat area. Hopefully with space to still allow storage on top. These are working out at 12kw based on 5 batteries and 120kg or so total weight. This will give a good front rear weight balance. Probably good for 50 miles range based on 3.5 to 4 times the range in miles per kw. A tesla is around this. I might even utilise the fuel tank area too. Batteries spec is 60 volts per battery. The inverter is good for about 400 volts. So potentially run with 6 batteries and with some overhead. Apparently the BMW 5 series hybrid sp41s come with an extra battery (6).

Range. Well you might think 50 miles isnt great. But to be honest 95% of the journeys I do will be well under that - so great for what its going to be used for. As new battery tech comes along this can be accommodated to increase range. There are various battery technologies which are almost ready for production which will release more range.

If you look at the opto mini video I shared earlier they had the inverter output set to 25% power output. Even at that it was very sprightly. Worth considering the benefit of a lot of power at low RPM of an EV comparative to an ICE engine vs range.

Here are specs of the various IBM battery types on openinverter site:
https://openinverter.org/wiki/BMW_Hybrid_Battery_Pack

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With all the discussions and modifications we have seen over the years with honda v-tech and other mini engine conversion swaps you have to wonder how legal they are given DVLAs data on what you can and cannot do to the body shell. subframe or chassis. without hitting the points for an IVA.

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Vehicle Control Unit (or vcu).

There seems to be a couple of options here.

Zombieverter
https://www.evbmw.com/

or

a 3 pack solution from

https://citini.com/product-category/bms-and-controllers/ based on simpBMS

I've ordered a zombieverter. Not sure what I am doing about battery management for charging at the moment. Some suggest simpBMS but something for me to research more on.

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managed to source a relatively new 20kw pack from a 2025 330e bmw touring. Should be good for 80 plus miles I recon.

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While I had some spare moments today I built up the spare subframe I had around putting all the upper and lower arms in, along with steering hubs and outer cv joints and metro drive shafts offered up to the outer cvs to get a feel for how its going to fit and align.

Bought a second set of outlander inner cvs and dry fitted in the outlander gearbox without the clips on, Then mock lined up the whole assembly up with some white marker (tippex in my case). Obviously I need to cut and sleeve the metro drive shafts on the outside to the outlander ones on the inside same as others have done with the minis. (already bought some cheapo 3.25mm walled tube x 25.4mm OD as a mock up. Will need cut and drop the diameters of both slightly on the lathe. Interesting the inner cvs on the outlander look a lot more feeble than the metro ones.

Need to chock everything up with some wooden blocks to get a feel for full top and bottom suspension travel but looking good, when sighted on sideways, compared to my other ICE engined Midas. (I have 2, the other is convertible but sadly has no room to convert to EV like the Coupe can).

Once happy with alignment I can start to make some mounting plates off existing bolt holes around the subframe. I am thinking 6-8mm plate with some gussetting probably on my plasma cutter after making cardboard templates.

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Heres one of the BMW SP51 batteries partially stripped down on youtube for those interested. This is the 20kw high voltage battery pack used in the 2025 on 330e bmw touring (estate) plug in hybrids:

https://www.youtube.com/watch?v=4m67B1P0Glg&t=237s

right - now back to the convertible to replace some exhaust bobbins.