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Working on a 1989 Classic Mini EV Conversion

12556 Views 80 Replies 10 Participants Last post by  scottherrington
Hello Everyone,

Starting work on my 1989 Mini. Thinking of keeping the original gearbox and mounting a Hyper9 motor directly on top of it. Using SilentSync sprockets and belt as a drive system. Have something similar to ´s conversion in mind. But interested in using the Hyper9 9 and some Tesla modules from the get go.

Also considering the EV Europe system:

I have no advance knowledge in EV conversions so I want to keep everything as simple as possible for this one.

Interested in getting some feedback from you guys who are the experts. Let me know your thoughts.

Am I in the right path or is this combo I have in mind a not so good Idea.

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Hello all,
may I add some remarks:
I have converted my Mini with a 27kW-powertrain (from a Th!nk as donor car). With these 27kW I can make the front wheels spin at any time I want (sometime I fail to avoid it) from zero to approx. 60km/h. Top speed is 105km/h, because I have limited the max. rpm of the motor (AC, asynchroneous) to 10.000 1/min. Some people tell the motor can do 12.000 1/min, maybe I will try this some day. The car makes a lot of fun!

To me it appears not reasonable to install a 80kW-engine into a 680kg-Mini with a front-wheel-drive. It might make sense if you build a RWD- or AWD-car, or if you want a top speed far beyond 180km/h.
You should also consider that in order to make 80kW, the battery must provide this power; doing that without damage, it must be a big (and a heavy) one. Which might not suit to a Mini.

Sorry if this does disappoint You, it is just my opinion. After all it is up to You how to convert your Mini. I whish you success!
I installed the entire drivetrain (motor, reduction gear/diff). During the mechanic installation I learned that Caspar Hille from Norway (he has posted a thread here...) had done the same thing already some years ago! He could give me some highly appreciated hints, fortunately. What a nice project!
Motor/gearbox-assembly fits nearly perfectly into the Mini-Subframe, there is only one area (front, RH) to be cleared. It was much easier than to install a LEAF-drivetrain, as You do.
I could keep the original controller (both motor and controller are from Siemens). With a 486-computer (!), the right software, the Siemens-manual and a OBD-to-RS232-adaptor (all this appeared harder to find than the donor car itself), all parameters can be tuned.
Currently I am converting my second Mini, some information (also little from the first one) can be found here:
Have a great day!
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Nice! I wish those cars were sold in the States.
Surprisingly, the Th!nk was built in the USA! At that time they belonged to the Ford group. Some years later when the car manufacturers made the EVs disappear, many Th!nks (440 ea?) were saved by bringing them outside (mainly to Europe).

I was also considering a AWD, in fact there is a Audi-TT rear axle in my garage, waiting to be fitted into a Mini some day...

Brian, I do not remember the Th!nk's battery specification. I have the drivetrain from the early A266. The later type was the A306, with more power and various battery technologies. This explains different figures concerning power and capacity.

An electric vehicle does not need to be heavier than a ICE-powered car: my Mini is 660kg, while original specification was 680kg. My battery has nominal 16kWh (90kg) which gives me a range of about 100km. I have a set of battery-cases that give me additional 50% range, when I need it (this happened once in the last 12 months).

Have a nice day!
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Coming back to the topic of this thread, which is Scanales' request for information:
I highly recommend to skip the Mini's gearbox - it is a heavy monster!
Just had a closer look to that motor-diff-assembly from Swind, a nice composition. It is my impression, however, that the diff.-housing has a great diameter and requires a lot of space, which is missing in the Mini. Would be interesting to see in detail how they install this into the Mini-Subframe. After all, the specifications of their Mini are pretty good. Maybe "pickmeup" made some photograph?

Besides, there is also this company in France:
and this one in the Netherlands:

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Expanding the rear battery-box is what I did in the boot. Very easy and effective. The other pack is located under (not between) the front seats. This is somewhat tricky, but feasible.
However there is weight missing on the front axle now. In my current conversion project I am locationg one set of batteries is in the trunk.
Scanales: You can add considerable space under the rear seats by cutting out the seat's support panel and reinstall it horizontally. You will need to ad a narrow vertical strip from left to right, and to cut out a wedge from the seat's foam. This measure is invisible, and even the rear passengers won't notice it when sitting there. I can post a picture, if required.
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Thank You. Oddly enough that space is currently not used, as the car has the expanded battery tray in the trunk and a largely expanded cross-tunnel under the front seats. But some day this may be an option...
Again, remember not to make the car too light on the front. Spinning wheels are useless (ok, some people like that), I assume it is real acceleration most of us are looking for.
It is good to put some weight back into the engine bay. Keeping the rear seat keeps the orginal look, which I like. Consider that passengers there also need some space for their feet, I don't see that in your picture. If possible try to put the batteries of the side compartment down into the pockets, instead above them. And some batteries do fit under the front seats.
Of course you will need to split your current modules is like in real life: you get nothing for free.
Converting the rear suspension in that way might be good if you look for ultimate performance.
Installing too much weight in the car's back, is certainly unfavourable.

My mini probably has a very similar weight distribution to Tremelune's conversion. Actually, it was my intention to equalize front/rear distribution to a certain degree. Cornering ability, especially through roundabouts, has become spectacular. However I have limited acceleration (nominal 27kW only!) because front wheels are spinning. (Tyres: 165/70R10 Yokohama A032)
Would be interesting to learn if Tremelune could confirm this impression, or not.
I consider my car's current balance as a mistake, meanwhile.
Next project will have it closer to stock. If ok., I may modify the first car accordingly.
This is my personal experience and what I have learned from. And-of course-following my personal preferences.
@ Tremelune:
It's a pity that most probably we will never have a trip along Mulholland Drive together with our Minis, or experience where each other's limits might be.:)
i have seen some other information about the swind e motor and they do have to cut into the rear of the subframe and there is some extra brackets required for mounting points.

the only photo ive seen on the internet with the motor in the subframe is this one below.
There is more info about swindon, meanwhile:
I just had a déja-vu regarding the motor/subframe picture.:)
Not really cheap, however.
Must be a very (!) compact battery. On the current project, I managed to install 8kWh only on top of the motor.
The reason might be that the old-fashioned Siemens-controller requires much space there.
As soon as lockdown is over again in the UK im visiting them for a test drive....
hopefully earlier than 2022!
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