i3 conversion - am I mad?

[SOL111]

I've been thinking about this for a while and a recent visit
to the EV experience centre in Milton Keynes got me thinking.

I love my i3s but think it would make a great basis for a 2 seater conversion given the RWD layout, low CoG and pace.

Looking at it, it doesn't seem unreasonable (albeit a money pit) but if doable would make a good garage project.

Having said that, would a Caterham kit be easier

[anonymous-user]

The problem with "skateboard" based chassis is that you can't really ever get the occupants low enough to be "sporty". Look at the height of the top of the battery in those pics, that's higher than the transmission tunnel in a Caterham, and practically level with the dash!

[SOL111]

Thanks.

You're right but the Caterham is quite extreme in terms of hip height. I thought I could ditch the 19" wheels for something like 17's but get your point. Even with smaller wheels and bucket seat you'd be sat a fair bit higher than an MX5.

A mate who works for JLR reckons this is why EV's are more appropriate for SUV's and higher riding vehicles and is probably right. I would compromise a bit of height but may be better to just get the Caterham kit!

[RobDickinson]

Max_Torque said:

The problem with "skateboard" based chassis is that you can't really ever get the occupants low enough to be "sporty". Look at the height of the top of the battery in those pics, that's higher than the transmission tunnel in a Caterham, and practically level with the dash!

Why Rimac etc are modifying the skateboard to not have batteries where the passengers sit, and have more in the 'transmission tunnel' etc

[covmutley]

Would certainly be interesting! Complicated electrics aside, I think physically it may be quite possible as the cabin is quite separate, as you can see in those photos.

I would say track need a widening, although if height is substantially reducing, maybe not. Definitely different wheels and tyres. The ride in my i3 is annoying me when driving quickly.

Go on, what's the worst that can happen??!!

[anonymous-user]

RobDickinson said:

Max_Torque said:

The problem with "skateboard" based chassis is that you can't really ever get the occupants low enough to be "sporty". Look at the height of the top of the battery in those pics, that's higher than the transmission tunnel in a Caterham, and practically level with the dash!

Why Rimac etc are modifying the skateboard to not have batteries where the passengers sit, and have more in the 'transmission tunnel' etc

The problem is you then end up with the occupants wedged uncomfortably between the battery and sills, and you really want the most battery volume in the squarest form factor you can have. You could certainly re-form factor an i3 battery, into say 3 chunks, 1 in the back next to the eMachine (where the ReX bit would go) 1 in the front (currently mostly free space) and one narrow one down the middle. However, the cooling you be a bit more difficult and the crash performance way worse, which i guess for a home brew special isn't the end of the world!

A second option, is to keep it a strict two seater and go "cab forward" and put the battery across the back between occupants and the eMachine?

[SOL111]

covmutley said:

Go on, what's the worst that can happen??!!

Have you ever watched the Simpsons episode where homer meets his brother and designs his new car!

I agree about the wheels and tyres. Imo it's something BMW did to get as much mileage from the batteries as possible but has compromised the ride a bit.

I thought about approaching someone like Morgan but was a bit of a fantasy brain fart as it would likely bankrupt me. So it'd have to be cheaper but not so cheap the result would be cack.

More homework required!

[oop north]

I would have thought you would be better getting a used sports car and converting it to leccy

[SOL111]

oop north said:

I would have thought you would be better getting a used sports car and converting it to leccy

I've seen this done and it looks great except I have a few fantasy cars, one of which is the Morgan Three Wheeler. If I bought one of those it'd be job done already and I'd just enjoy the sound of the engine.

Looking at the VW ID Buggy in the other forum, that looks like an option but at this stage I really have no idea.

Shame we're not quite like America as they're great at this kind of thing.

[Boxbrownie]

It’d be the right proportions for a Beach Buggy type vehicle I reckon, maybe not a sports car but a modern twist on a classic.

[anonymous-user]

I was in at my local BMW dealer today collecting some new brake discs for the Luxury Tractor, my 335d ;-) and they have a nice ex-demo i3s. Nice car, but after doing the sums it's looking like a fair chunk of cash to swap up to from my boggo small battery i3, so i think i'm just going to battery swap my 64ah into a 94ah!

I just need to work out what the 'coding' implications are, which should be relatively straight forwards i think!

[SOL111]

Max_Torque said:

I was in at my local BMW dealer today collecting some new brake discs for the Luxury Tractor, my 335d ;-) and they have a nice ex-demo i3s. Nice car, but after doing the sums it's looking like a fair chunk of cash to swap up to from my boggo small battery i3, so i think i'm just going to battery swap my 64ah into a 94ah!

I just need to work out what the 'coding' implications are, which should be relatively straight forwards i think!

Sorry, are you swapping out your old 64Ah and upgrading to a 94Ah? What are you doing with the 64Ah battery? Would make a decent powerwall if you're not trading it in.

Will this involve you having to remove the chassis from the body shell? If so I'd be really interested to hear your experience.

I'm hoping that a company like Lion Smart hurry up with their upgrade.

[anonymous-user]

yes, the plan is to source a 94ah battery from a crashed i3 and swap it into my 60ah version! The battery removed is going in the garage as a DIY power wall ;-) (or is being turned into a trailer 'range extender'..... ;-)

[Europa Jon]

Looking at the skeleton of the i3, I'd say a beach buggy type look is more feasable than a low slung Caterham jobby. Failing that, a body style to suit those skinny tyres like a 1920s saloon car. I hope you've got deeper pockets than me!

[Evanivitch]

The battery on an Ampera would suit the transmission tunnel shaping that you might like. I've seen it out into an Elise that used a custom BMS and Tesla motors.

You've got to be very switched on with your software, CANBus and high voltage systems to make a kit car from OEM parts

[130iTrack]

Max_Torque said:

yes, the plan is to source a 94ah battery from a crashed i3 and swap it into my 60ah version! The battery removed is going in the garage as a DIY power wall ;-) (or is being turned into a trailer 'range extender'..... ;-)

I read somewhere that the 94ah batteries aren't backward compatible with the 60ah versions. You would need a different SME I think and that would probably not be compatible with the rest of the ECU's in the car. You would also need access to an EOS tester which BMW uk will not supply. I'm currently trying to buy one from overseas.

[130iTrack]

[quote=SOL111]I've been thinking about this for a while and a recent visit
to the EV experience centre in Milton Keynes got me thinking.

I love my i3s but think it would make a great basis for a 2 seater conversion given the RWD layout, low CoG and pace.

Looking at it, it doesn't seem unreasonable (albeit a money pit) but if doable would make a good garage project.

Having said that, would a Caterham kit be easier

As long as you don't upset any of the ECU's in the car it would be possible. Note that BMW UK won't touch any electric vehicle that has been modified in any way and won't give you access to the EOS tester you would need to be able to un-brick the car.

I'm trying to convert a classic car to electric using an i3 and have hit quite a few walls. Currently trying to buy an EOS tester from overseas and hire a hardware engineer to help me hack the SME.

Tread carefully!

[SOL111]

Many thanks for the info and heads up.

I think I need to do lots of research before I get into this. Just reading so far has given me food for thought as a buggy type thing is most likely the most appropriate. But this brings new challenges!

I did find these guys and funnily enough, one of my mates in mid Wales knows of him, although they do their own conversions.

https://www.electricclassiccars.co.uk

Best of luck with yours. Would be great to hear about it once you're done.

[Dutchy00]

I think or would make a Caterham way too heavy. But if you want to try, I'd go for a Dax or something like that.

That being said, I believe the new VW beachbuggy EV could be quote fun, despite not being fond of EV's myself in general. Maybe you could look into that for inspiration.