Trigger warning: EV and body conversion

[Tom Cheesewright]

Putting on my helmet before I introduce myself here because of what we (me and my daughter) are planning: first of all an electric Z3, then ultimately a Z300s body conversion. Realise this will be tantamount to blasphemy for some, so sorry!

Long-time BMW fan (E36 first, later E39 - still one of my favourite cars ever), and just bought a Z3 in need of some love. Broke all the rules and bought it unseen from the other end of the country (I'm in Manchester (UK) and the car is in Cornwall). It arrives in a couple of weeks when I can start to measure up.

Currently experimenting with the electric drive train - a mixture of Toyota and Mitsubishi parts right now but may end up being Lexus (300hp electric CVT gearbox) and BMW (batteries from modern hybrid).

Documenting things over at http://projects.tomcheesewright.com/ev-project.html if you're interested.

Joining here because forums are always invaluable and will need to do some digging on parts numbers, and repairing electric hood amongst other things. And because I'll likely be hunting for parts and looking for recommendations as I repair and upgrade.

Cheers,

Tom

 

[spurs fan in a coupe]

Welcome to the forum, sounds like a great project, looking forward to the updates.

good luck

 

[DaveP]

Welcome indeed Tom. Really looking forward to your build. I do like a sacrilegious person and something out of the ordinary.

Dave

 

[pgunter]

That link is an interesting read. Amazing what you can put together.

E30 / E36 anybody

 

[t-tony]

Hi Tom and welcome from me near Lincoln. You’re the 2nd person on here converting a Z3 to electric power. The other is a young man who is still in education and I think his project is on hold till he has more time to devote to it.

Tony.

 

[Althulas]

Look forward to your progress.

 

[Tom Cheesewright]

Thanks everyone. A warmer welcome than maybe I was expecting! I'll update this thread with new info as I continue the project.
Car arrives first week of June and I'm waiting on the control board for the inverter too so I can test out the motor. Feedback over on one of the electric car forums is that it won't be super rapid with the current setup but should work. Fingers crossed!

 

[Stevo7682]

Hi and welcome from me in Scotland .
Like Tony said young lad was well into his project ( there is a thread about it) he had the electric motor hooked up to the drive train .

You should start a progress thread ( go to forums and you will find it start new thread ) as people on here will be interested in your build

Stephen.

 

[Tom Cheesewright]

That's a good idea - thanks Stephen. I'll start one over there.

 

[Tom Cheesewright]

Right, progress thread live: https://zroadster.org/threads/z3-00s-ev-project.37379/

 

[Mint]

Hi @Tom Cheesewright, to the forum from me too in Staffordshire. Looking forward to your build, sounds an interesting project

 

[Shelly]

 

[Redline]

Fascinating project. I guess the limitation you will reach is distance available from the batteries you’re able to install. I presume your unlikely to want to do all this and then drive live miss daisy. Do you have a target?
Considering the length of the bonnet are you intending to just use available space there and try and keep the weight balance to 50/50?
Mating an electric motor to a manual gearbox! Are you intending to drive just using one gear or will you gear it to use all the cogs? As we tend to use the audible feedback from a the ICE would using the gearbox normally need a different technique to prevent trashing the motor? As a 330e owner the initial take up on battery is phenomenal, but, even driven through the 8 speed ZF box, you soon run out of grunt from the electric motor. That however is an annular ring motor. With 14k rpm you’ve got plenty of revs to play with through a single gear in the box.
Also, will you be able to scavenge power back on overrun and braking?
So many things to consider. Wish you all the best for the project and look forwards to updates on progress.

 

[Tom Cheesewright]

Fascinating project. I guess the limitation you will reach is distance available from the batteries you’re able to install. I presume your unlikely to want to do all this and then drive live miss daisy. Do you have a target?
Considering the length of the bonnet are you intending to just use available space there and try and keep the weight balance to 50/50?
Mating an electric motor to a manual gearbox! Are you intending to drive just using one gear or will you gear it to use all the cogs? As we tend to use the audible feedback from a the ICE would using the gearbox normally need a different technique to prevent trashing the motor? As a 330e owner the initial take up on battery is phenomenal, but, even driven through the 8 speed ZF box, you soon run out of grunt from the electric motor. That however is an annular ring motor. With 14k rpm you’ve got plenty of revs to play with through a single gear in the box.
Also, will you be able to scavenge power back on overrun and braking?
So many things to consider. Wish you all the best for the project and look forwards to updates on progress.

Thanks! And good questions! Let me take those in order:

- Range: I'm being very conservative about this. I don't drive a lot so I'm really only aiming for a 50 mile range or so at first. As long as it's nicely driveable around town, that should be fine. I can upgrade with more later.
- Space: I'm *hoping* to be able to squeeze in the primary battery pack, inverter, junction box, AND motor under the bonnet. Not done precise weight calculations yet but my rough estimate is that that shouldn't be too different to the weight of the motor and ancillaries, though obviously I'll be removing some stuff from the back of the car which might disturb the balance a bit. Ideal world: I lose a bit of weight from both front and back. Will have to see how it goes and maybe find someone with some corner weights near here for testing.
- Gearbox: Very much an experiment. From what I understand about the motor it has plenty of grunt up to about 4,000 revs and then tails off, so it may be that I just leave it in a higher gear. We shall see. I need the shifter for reverse as I'm not (currently) planning to have a reverse mode for the motor, but that is all subject to change. Still to be seen what the cost of mating motor to gearbox will be. It's the splined connector that concerns me - could be expensive to make.
- Regen: Yes, in theory. Not massive gains to be made with a lighter car I don't think, so may or may not be worth the complexity given my limited range ambitions. But it is a feature of the inverter I'm using, so absolutely possible.

 

[Z Victor 1]

Glad I'll be dead before we all have to drive electric cars, but I will be very interested to follow your thread. Variety is the spice of life so a great project in my opinion. Never the less it just won't have the character of a nice noisy smelly combustion engine!

 

[Tom Cheesewright]

Glad I'll be dead before we all have to drive electric cars, but I will be very interested to follow your thread. Variety is the spice of life so a great project in my opinion. Never the less it just won't have the character of a nice noisy smelly combustion engine!

Ha! No, I will certainly miss them. It's not that the electrics have no noise, but it's definitely going to take a while for us to appreciate the sounds the way we might a nice straight six or V8.

 

[Nodzed]

Hi & Welcome. Looking forward to this.

 

[Nodzed]

Right, progress thread live: https://zroadster.org/threads/z3-00s-ev-project.37379/

Just read through your project and can't decide if you're a genius or a lunatic
Good luck I'll be following.

 

[Tom Cheesewright]

I'm not sure either! Time will tell.

 

[Redline]

Glad I'll be dead before we all have to drive electric cars, but I will be very interested to follow your thread. Variety is the spice of life so a great project in my opinion. Never the less it just won't have the character of a nice noisy smelly combustion engine!

Can still have tyre noise

Hoof it and you can easily spin the rear wheels. With no ECU intervention it'll be good fun. An LSD might be good enhancement.