8 replies to this topic

[Forestway]

Hi all,

I am doing an EV Conversion on ‘72 mini moke, using a hyper 9 motor, 120hp and 173 fp of torque, I have complete battery from a Tesla model X,  this has 16 battery modules and I will be using 6 of these to get 136VDC which will give max performance from the motor and decent range of about 150 miles when being sensible.

 

The original plan was to use the stock mini gearbox, but I’ve been told by a few people that the gearbox won’t be able to handle the torque, also mounting the motor over the gearbox and adapting the drive was going to be very tricky, so using my very best man maths I have carefully calculated that it’s best to go RWD, as I figure if the wheel are gonna spin it will be more fun if it the rears.

 

So I come speaking knowledge of minis, mokes in particular and especially RWD conversions, Mini tec in the US do a great looking RWD subframe but it will be more than £2K delivered, so I am considering different options including cutting down the complete rear end of a MX5.

I will be using the diff from an RX8 as it has a low final drive ratio with the motor connected directly.

 

I’m sure most of this (the RWD part) has been done before, so I look forward to scanning the archives.

https://www.instagra...m/mini_moke_ev/

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[Spider]

Hi Steve,

 

This certain does look an exciting and interesting Project.

 

I can see you've put some time in to looking at various drives and power sources for it.

 

Where the Tesla Batteries hard to come by ?

 

Also, in regards to a Gearbox, I'm not sure you'd need one would you ?

 

As you have mentioned, I see the Motor has it's peak torque at Stall Speed and that's some very respectable numbers  - 173 ft / lb (235.1 Nm) !!

 

Chris

[Forestway]

Hey Chris,

I bought a complete model X battery, so will only be using 6 of the 16 battery modules for this project with a few to spare to make a power wall or for the next project ( mrs fancies a Fiat 500 classic)

yes I figured direct drive is they way to when using such a torquey motor and to my mind using the existing gearbox is lazy engineering, finding someone to make a custom RWD subframe is proving to be difficult, if I can’t find someone, I will take a grinder to an MX5 rear end  and see what happens.

more pics on my company web site.. www.sec-marine.com

[Forestway]

Got the Tesla battery my one of my local scrappers, stripping it down to its cells is going to be interesting, but it’s stuck on the Isle of Wight now, so can’t get to it until after the lockdown, and this cold or C19 that I have does one.

[HUBBA.HUBBA]

Looking forward to seeing this involve. Is like to put a rear mounted engine in the back of mine one day.

[Forestway]

So I’m embarrassed to say that I think I’m gonna revert to the original plan of FWD, as I have reached out to a load of different companies to get a uk built version of the minitec subframe, but no one seams to want to take my money.

I was flirting with a narrowed MX5, but then I would need to change the front also, and I could imagine it all spiralling out of control, and the reason I got the moke in the first place was (apart from the fact that’s I had always wanted one) because of the apparent simplicity of the build....at least in my mind.
 

So back to Plan B- I am thinking of using the chain driven diff from Pro-Motives R1 kit, as this would also give some apparent freedom on final drive ratios, but it looks like there is very little clearance between the diff sprocket and the inboard CV cups, it looks like the STD is 16T but I would need 19T minimum, If anyone can give me some advice on this it would be great.

 

in other news, the 1st delivery of Electrical gubbins is here at last, with just the motor and throttle pedal still outstanding, my Tesla battery is stuck on the IOW in a locked down facility, so I can’t get at it to start the Tesla battery stripdown, and that’s going to be quite an exciting job.

 

..so not much of an update, but it’s hard to get anything done right now.

[Forestway]

Thanks to a post on an EV build forum, I have been reminded about the Quaife QBA5R / QBA4R, which although pricey looks like it could save a whole load of hassle with chains (drippy and needing maintenance), or Belts (just don't know where to start).

 

These Quaife units uses fiesta/escort shaft or Lobro joints...an idea how I could match this up to the mini drive flanges ?

Quaife are not answering the phone or replying to emails right now.

 

Cheers if you can help

 

 

 

https://shop.quaife....unit-no-reverse

[Spider]

So I’m embarrassed to say that I think I’m gonna revert to the original plan of FWD, as I have reached out to a load of different companies to get a uk built version of the minitec subframe, but no one seams to want to take my money.

I was flirting with a narrowed MX5, but then I would need to change the front also, and I could imagine it all spiralling out of control, and the reason I got the moke in the first place was (apart from the fact that’s I had always wanted one) because of the apparent simplicity of the build....at least in my mind.
 

So back to Plan B- I am thinking of using the chain driven diff from Pro-Motives R1 kit, as this would also give some apparent freedom on final drive ratios, but it looks like there is very little clearance between the diff sprocket and the inboard CV cups, it looks like the STD is 16T but I would need 19T minimum, If anyone can give me some advice on this it would be great.

 

in other news, the 1st delivery of Electrical gubbins is here at last, with just the motor and throttle pedal still outstanding, my Tesla battery is stuck on the IOW in a locked down facility, so I can’t get at it to start the Tesla battery stripdown, and that’s going to be quite an exciting job.

 

..so not much of an update, but it’s hard to get anything done right now.

 

I don't thing there's anything to be embarrassed about in contemplating a return to FWD.

 

Doing a RWD conversion in these cars, in a way that doesn't 'eat' in to the Rear Tray is not easy at all. I've been looking at all this (for different reasons) for a very long time and the only sensible way of doing it I can see is to retain trailing arms in one way or another, however, the standard arms don't readily lend themselves to fitting a live drive shaft through them and the standard rear subframe is also in the way of the drive shafts.

The UK factory back in the early 60's did such an arrangement, though, I have no photos of that particular set up. It was however robbed from that Mini Moke and fitted in to the 4WD Clubman that ST built and raced in the early 70's. Our local factory also built a few 4WD Mokes along a similar arrangement but, IMO, all these were a hasty and poorly engineered construction.

 

With the Chain Drive / Sprocket arrangement, sorry, I'm not familiar with that. Any links or Photos ?

[Wazzah]

The Quaife drive unit looks very nice and it probably wouldn't be too much of a stretch for them to supply mini stubs.

They already manufacture ATB's with pot joint stubs!

Forestway's link has a picture and I immediately thought of the drop gears and associated housing in our own mini's.

The mini gearbox case itself could make an easy platform for a bolt on electric motor that drives through either the original crankshaft boss or even the Idler position.

Solves the reverse issue (assuming you cant just change polarity on your motor) and allows you to run whatever diff option you wanted.

Solves any subframe issues.

Obviously some sort of windage tray to protect the motor from gearbox oil.

Perhaps an electrical oil pump to circulate gearbox oil through a filter.

Downside includes the weight penalty of 26kg for the gearbox case full off gears you don't really need.

If the motor itself is easily reversible you could redesign the first motion shaft into one shaft that extend all the way back to the diff pinion.

Extend it a bit further and use a KAD pinion support bearing.

Similar gearboxes to the Quaife QBA5R are readily available on Harleys and Royal Enfields

As far as rear swing arms are concerned Datsun 1600 ones have a drive flange integral in the arm and their rear end is basically a rubber mounted sub frame.