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· Registered
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Hi Folks,
Long time lurker and learner here from the UK (South Wales), thought i'd start documenting my build as it slowly progresses.

The vehicle:
a 1961 Land Rover 88" Series 2 - bought brand new by my grandfather in 1961, then was passed down to my late father in the 80's, and on to me in 2009 where i stripped it back to the chassis and rebuilt it.

Here's one of my favourite pictures of it doing what it does best, i.e. being awesome! This was after arriving home from rescuing my sister during the 'Beast from the East' in... 2018 i think it was.
View attachment 126400

We've been pretty much everywhere in it including a guelling LEJOG and then the "North Coast 500" in Scotland a few years ago, and probably hundreds of camping trips.
Over the years it's had various different engines:
  1. Left the factory with a 2.25 petrol,
  2. Dad fitted a 2.8 V6 petrol Cologne engine in it in 1990-ish,
  3. I fitted a 2.5NA Diesel (cheap insurance at the time), as well as:
  4. 300TDi (great engine, not bad speed but noisy as hell)
  5. Essex V6 3.0 which i built EFi for using the Speeduino/Arduino platform, my build for that conversion is here on the speeduino forum. This is a pretty rapid engine but to be honest too fast for what it's in... the more you rev it the more power it seems to give, and it just gets scary. lol. It's also now extremely expensive to run! Also quite loud, and the engine weighs a ton being cast iron everything. I also have a stubby R380 gearbox squuzed in there.
I have disc brakes using the now defunct (as far as i know) YakYak classics conversion kit (defender discs, discovery calipers) and P38 power steering (range rover). So it's basically 99% original...
This is where my next adventure begins... A background from me - i work with 'smart buildings' mainly with comms including with lithium / other weird chemistry battery installations in grid connected buildings, so have a basic/fair idea of how not to burn my fingertips. Also am a keen CAD user as i also make prototype stuff at work - obviously Electric Vehicles are a whole new frontier for me so that's why i'm here! We have a bunch of different EV cars and vans at work so am familiar with the good and 'bad' bits of EV driving and charging.

As my Landy has an LT230 i started looking at ways to drive the transfer box directly with a motor rather than leave the original gearbox in place - this should leave me with a lot more room under the bonnet for a larger battery pack, with the motor tucked away somewhere in the transmission tunnel. I'll also save weight as the R380 is fairly hefty.

I like the look of the Hyper 9HV & controller, and see that Jaunt Electric Videos (YouTube vid) has used a hyper9, as well as This kit from Evolution Australia.

I've currently got a 1.667 ratio LT230 on my workbench which i'm rebuilding. This, coupled with my 3.54:1 diffs and 215/85/R16 tyres should give the following gearing in high range - see the MPH column i've added to the left in an expert way: basically 1mph is 66rpm at the motor.

View attachment 126402

I expect to mostly use the Landy for commuting the 15 minutes / 7 miles to work, which means doing either 30mph or just under 70 which i currently do. I don't need it to be a rocket ship - i am aware this car is a tin shed on wheels, and it can already go extremely fast, but i just choose not to go that fast as i get older (wiser!). We also use the landy for camping, and christmas shopping where people are free to slam their car doors into my battered doors. lol

To make a start and because i needed a huge paperweight i decided to 3D print a full size dual shaft Hyper 9DHV motor, i like to have something hands on to chuck around with a tape measure in the other hand:
View attachment 126403

View attachment 126404
Needs some sanding or whatever but it certainly does the job!

To drive the LT230 from the motor requires a shaft adapter which i've drawn up and will hopefully get a quote for in the coming days. If anyone knows the exact spline designation for the R380 / LT77 mainshaft please speak up but i'm quite sure i've got it measured correctly. Shaft connector mockup:

View attachment 126405

Measured the spline profile of a brand new shaft with a Keyence VHX-7000 microscope, which measures surface topography of 'stuff'. a very cool machine.

Back in the world of CAD i've got an assembly with a pre-prototype adapter plate and shaft converter:
View attachment 126406

Cutaway view: (are you bored of pictures yet? apologies). Aiming for the shaft converter to be a transition fit on to the keyed shaft, and held in place with the purple cap head bolt. Needs to be tight enough to stay concentric but not so tight that you can never get it off.
View attachment 126407

Now, i was a bit worried about the shaft coupler not being meaty enough but a stress simulation (in Autodesk Inventor 2022) at 2000NM i.e. 10x max motor torque shows the 300M steel nowhere near its yield point, so this is good news. This simulation has motor torque applied at the keyway, and reactive torque applied on the surface of the splines.
View attachment 126408
Also(!) the ZF gearbox to LT230 adapter used in some older range rovers(i.e. this ) has much thinner walls as well as sharp splines inside so we can only be on a winner here...!

To do in the short term: - get my LT230 to a CMM in the next few days, luckily my distant colleagues have one so i may shoot a few emails off tomorrow. So far i've measured the LT230 holes with a good set of calipers, verifying measurements as best i can with a laser cut 'gasket', but a CMM will tell us for sure:
View attachment 126409

as for remaining hardware such as batteries, i'd like to use Tesla batteries as used in other Hyper 9 installs, I like the Tesla packs as they're water cooled and seem to be popular. As for BMS i'm leaning towards the Orion with the little cell breakout boards, but simpBMS has been mentioned too, and is less wiring -more googling required.

Charging: I really want to go down the 'smaller battery pack with quicker charger' design route but so far haven't found a solution above 6.6kW. CCS seems out of the window as my max battery voltage is going to be 144V to suit the Hyper 9 HV controller, i.e. the SME AC-X144 - and CCS minimum DC voltage is 200V at this moment in time. I see the Tesla Gen2 charger is 10kW or so but i don't think CAN is implemented just yet. It'll be a while before i have the cash to buy chargers, BMS and batteries so there's plenty of time to learn yet!

Thanks to those who have answered my questions on other posts here, and thanks to all of you who have taken the time to make youtube videos.
Really interesting project. Following with interest.
Learn't to drive in my Dad's Series III 2 1/4, when the chassis nearly broke in half towing our caravan back from the lake district we re-built it on a galvanised chassis.

Regarding driving the LT230 directly - have you done speed calculations using the low range gear reduction? to give you better acceleration - as you'll obviously never need 100mph in a series LR! 55 was scary for ours.


· Registered
31 Posts
I do wonder if you'll get the low end torque you need, mounting direct to the transfer box. Long ago, I converted a Freelander using a Suzuki SJ413 Transfer box and a Siemens motor which had roughly the same peak torque as the Hyper9. The final drive ratio is similar - but I found it struggled with steep hills and so ended up driving it in Low Range most of the time.

Interesting, how did you find it driving in low range on the road?
Why not use low range all the time? or did that limit your top speed?

· Registered
31 Posts
If you use your 1.667 LT230 reduction & your axle reduction of 3.54 that gives you a total drivetrain reduction of 5.9:1. The Hyper 9 HV looks like it has a max torque of around 220Nm? - so this would be a max wheel torque of 1298Nm.

Using the 2.25 petrol series engine as an example comparison - it has a max torque of about 168Nm - so would give the same wheel torque when geared to total drivetrain reduction of 7.7:1.
Using the same axle and LT230 gives a gear box reduction of 1.3:1 which would be equivalent acceleration to the 2.25 petrol stuck in 3rd gear.

I know you're not drag racing - but I learnt to drive and spent a lot of time in my dad's 2.25 series 3 and would say third gear acceleration was rather pedestrian.

The 4.7 ratio axles would give you 1723Nm wheel torque (33% more) which is more like acceleration in 2nd gear (well more like 2.5 gear if there was such a gear!)
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