Working on a 1989 Classic Mini EV Conversion

How many kWh is that?

Space in the engine bay is tight, but if you ditch the brake booster a lot of space frees up. It seemed like a real pain to get a useful amount of Leaf batteries up there, but it seems like maybe the OXT batteries will fit. I wonder if you could get two...

What's the motivation to keep the rear seat? I put a 200lb guy in the back of mine once, and the car was almost dragging on the bump stops...

Trunk space is ample.

21.3 kWh. It’s 6 of them. 4 back seat and sides, one in the trunk and hopefully one in the front.

No real practical motivation for keeping the rear seat. Would be nice to have, It can go if we have an issue finding space for the batteries. I thought a slight mod on the side compartments could help us gain some battery space and keep the seat, that’s all.

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 again...it is like in real life: you get nothing for free.
Markus

Look under your car at the back
If you remove the rear subframe - which you can do if you use coil overs and reinforce the rear wheel arches
There is a lot of wasted space under there

Sent you a message Sir.

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.

Markus

McGeesCustomMinis said:

Stock was 1,575lb 64/36.
EV setup with leaf: 1,650lb 56/44

Is this really a bad thing? What am I missing?

Click to expand...

It's not terrible in either total mass or front/rear distribution, but the rear mass is all overhanging beyond the rear axle line, which is undesirable for handling response in a short-wheelbase vehicle. Also, the driver and any passengers are behind the midpoint of the wheelbase, so weight distribution will be more rearward than the empty values.

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.
Markus

schelle63 said:

... 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.
...
I consider my car's current balance as a mistake, meanwhile.
Next project will have it closer to stock.

Click to expand...

I agree, unfortunately. A car with equal load on front and rear axles and two wheel drive should certainly drive the rear wheels, not the front.

Production EVs adapted from front-wheel-drive conventional vehicles have some of the same problem for the same reason of replacing a front engine and transaxle with a lighter motor and transaxle plus battery centred behind the midpoint of the wheelbase. The original Nissan Leaf's odd rear shape wasn't just the funky French-Japanese styling - it minimized rear cargo capacity and rearward length of the cargo compartment to avoid overloading the rear axle; it even has a completely empty space under the rear cargo floor where there should be a spare tire well or hidden cargo compartment, but they didn't want any more load back there.

My car's acceleration is for sure limited by traction up front, but...it's still quite the little monster. Not having experienced the insanity of a Honda B conversion, maybe it's tame, but...moving to rear or AWD would take quite a bit of work, and even then you'll introduce the fun of accidental throttle-induced oversteer. Crazier Minis have been built, but they often come with the disclaimer that maybe they went too far beyond the fun zone. I choose to be content with some throttle modulation until 30mph or so.

I'm of the mind that I worried about weight distribution too much for scooting around the city (which is the purpose I built it for). It sure does well on Mulholland Drive, which is nice. That said, I'm not sliding around on public roads, so I can't tell you how it feels at the limit.

@ 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.

People taking about minis and traction limits
The unfortunate truth is that the mini suspension and handling is deceptive

With a small amount of power a mini feels GREAT!
If you get a bit more power its really not very good!

My 1430cc mini with about 110 hp was well over the optimum

When I changed the front suspension and fitted a 2 litre Lancia engine with Hollbay Cams and twin webers I went from 110 hp to over 170 hp
AND it had MORE traction

I really like the mini suspension - but its not very good if you have over about 70 hp

pickmeup said:

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.

Click to expand...

There is more info about swindon, meanwhile:
I just had a déja-vu regarding the motor/subframe picture.
Not really cheap, however.
Markus

If find it interesting that the Swindon conversion, now that it has reached commercial product stage, places a 12 kWh battery pack right on top of the motor. The resulting weight distribution will be even more front-heavy than a stock Mini, and if someone used that pack plus an additional rear pack (or two custom packs of similar total capacity and locations), the weight distribution would probably be reasonable.

Most conversion components, whether a conventional transaxle plus typical motor or a more integrated electric drive unit but from a larger front wheel drive car, will not leave enough space for a battery pack on top.

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.

schelle63 said:

Must be a very (!) compact battery. On the current project, I managed to install 8kWh only on top of the motor.

Click to expand...

This is an excellent point - there really isn't enough space there for a battery which either holds 12 kWh of energy or can effectively power an 80 kW motor, let alone both. Plug-in hybrids have relatively power-dense batteries of about this capacity, and they're much larger (e.g. Chevrolet Volt, Chrysler Pacifica Hybrid, Mitsubishi Outlander PHEV); battery-electric vehicles tend to a higher energy density but a BEV battery of this size typically can't handle this power output.

Something seems fishy, but maybe I should dig out actual measurements of the space.

As soon as lockdown is over again in the UK im visiting them for a test drive. They were working with a UK battery specialist for the initial prototypes called MEP Technologies.

pickmeup said:

As soon as lockdown is over again in the UK im visiting them for a test drive....

Click to expand...

hopefully earlier than 2022!