Another Electric MG F

[LrBen]

Hi All,

I've been a bit of a lurker here for a few years now. Had my current MG F for about two years, of which it has been on the road for about a month.
Bought it by accident when it sold on an Ebay auction for way too low. Got around to putting an MOT on it after having it for 6 months, then the HG gave out completely. Swapped in a new head gasket over the first lockdown last year, then the clutch started to slip a few weeks later.

At the time then I had just finished my Electric Quad conversion and was looking for something bigger to do. I figured since I was going to have to drop the rear subframe out anyway I might as well just convert it at that stage. That was July last year.

At this stage I have an electric motor and controller installed in the rear, using the original gearbox. Currently just fitting the battery box in the front and I am getting to some more technically interesting aspects such as how to handle the extra 100kg in the front. So I thought it was time I signed up to ask some more detailed questions.

[talkingcars]

Hi and welcome to the forum

Which motor have you used? What controller? What else have you done to make up for the lack of an ICE?

James

[LrBen]

I am using the rear motor from an Outlander Phev. Rated to 70kW but it also has 195nm of torque. So about 20nm more than the 1.6 that was there originally.
The controller is from a Gen 2 Prius. The nice thing about the Prius inverter is the built in DC-DC converter and the potential to use the hybrid side of it to charge the battery from mains. The main inverter has been tested to handle over 350Amps. So there is potential to squeeze out a few more kW of power and test the motor limits. The Leaf motor can output 300hp with the right inverter. Should it should be interesting to see how this one performs in this setup.

However the main aim is not performance but cost and experience. This whole setup is under £5k for materials and car. Will probably be well under £4k once I sell the battery cells I don't use since I bought about double what I am actually going to be able to fit in. This photo is a few weeks old. I now have a heater matrix on the left side that will handle motor and inverter cooling, as well as some more brackets.

Other ICE feature replacements. I have installed an electric vacuum pump and reservoir for the brake. Using a Volvo vacuum pump and sensor along with an Audi vacuum reservoir. I installed some universal heat pads in the seats for some driver heating. Windscreen heating is something I'll think about in the future.
There will be a teensy based controller that will send the correct signals to the dash so all the original gauges will work mostly correctly, this will also send rpm data to the PAS so that works. I have this working to the point of getting all the dash gauges moving. Just need to add in the correct inputs from the inverter and BMS.

Oh forgot to give a Location in my first post. I'm based in Somerset, UK.

[John SS]

Really interesting. Please keep the updates coming. I'm a real EV enthusiast, just wish I had the electronic expertise to tackle a similar conversion!

[LrBen]

The build thread is ongoing on the Open Inverter Forums here:
https://openinverter.org/forum/viewtopic.php?f=11&t=181

But I'll keep this thread updated with major milestones.

I was actually hoping that it would be a bolt on kit of sorts. Drop the rear subframe, remove engine, attach motor/controller/batteries, plug in a teensy to the right wiring loom connectors and away you go.

Unfortunately battery technology isn't quite there yet. It's possible, but you just wouldn't have much range. So I decided that I would have to cut out the spare wheel section in order to use the space in the front.

[Thiago81]

You're obviously a very switched on chap. Looks great and I'm very intrigued with what you're doing. What's your background if you don't mind me asking? Is that a manual gearbox?

[LrBen]

I'm a historian by education. But there isn't much call for that sort of thing so I bounced around workplaces for a few years after uni before getting into cars as way to avoid paying the garage to do a timing chain replacement. Self taught from there and now my day job is rebuilding engines for a Defender Resto-Modder.

Similar with the electric side. Started a quad conversion about 3 years ago at 48v so I could make mistakes at a slightly safer voltage. Picked up CAD/3d printing/CNC stuff from that project. This project is a little more involved on micro computer side, but it's interesting stuff to learn about.

It's the original PG1 gearbox. After the coupler that I made to connect the motor and gearbox that is what I think will fail first. It's all standard and 20 years old, I just changed the oil. On paper it's good for about 20nm more than the motor will supply. I can upgrade it if it fails though. I would like to get a limited slip for it, but torsen diffs seem very rare these day. I'm not about to splash out on a Quaife ATB just yet.

[talkingcars]

Looking foward to updates.

Over on the Tbar (link below) we have a dedicated MGF EV sub forum that you are welcome to also post in.

James

[LrBen]

Thanks I'll check it out.

[Deepfat]

What do I know about EV's nothing, I was good at scalextric though.
You mentioned windscreen demisting and you also mentioned fitting a cooling rad for the motor etc, cant the heat from the motor be directed to the screen/cabin or is it insufficient for the task. They also do petrol/diesel powered heaters for boats could one of them be adapted?, I know it goes against the concept of an EV but I think the mpg would not be that great.
On a lighter note how about fitting extra batteries in the doors to get rid of that "low rent rattle when closing" (not me saw it on another forum) we could have a nice satisfying THUD
Peter

[LrBen]

What do I know about EV's nothing, I was good at scalextric though.
You mentioned windscreen demisting and you also mentioned fitting a cooling rad for the motor etc, cant the heat from the motor be directed to the screen/cabin or is it insufficient for the task. They also do petrol/diesel powered heaters for boats could one of them be adapted?, I know it goes against the concept of an EV but I think the mpg would not be that great.
On a lighter note how about fitting extra batteries in the doors to get rid of that "low rent rattle when closing" (not me saw it on another forum) we could have a nice satisfying THUD
Peter

Using the motor and inverter coolant to heat the windscreen and cabin has been tried. Unfortunately the heat put out by it is pretty useless as the waste heat from a motor is tiny compared to a combustion engine.
Desiel fired heaters are an option and have been used. Or I can plumb in an electric water heater.

My door is already dropping without adding additional fire risks!

Update wise the project is coming along. I refurbished the front subframe, got some fancy refurbished suspension units and built a battery tray into the front subframe.
Batteries are being delayed by the global chip shortage which means I can't get my BMS system.
So I have been pushing ahead with the other things needed in the car, sorting out the control circuitry and wiring required, getting my head around the slightly complicated charging process and a few other things.
Worst case scenario on the batteries I can throw in a Prius pack just to move it around the yard. Hoping to get the rear subframe back in the car in a few weeks.

[mowog73]

I'm really enjoy reading about your conversion of an F to electric, I'm starting to considering doing this to mine someday.

[LrBen]

A bit of a repeat post but with photos. Got some fancy new refurbished suspension spheres! Also added in the cooling loop with a London taxi heater matrix as the radiator. There is a coolant temperature sensor in the loop which my arduino will read and if needed it can activate the engine bay cooling fan to increase cooling. I decided not to mess around with the suspension setup for the moment. I have new shock absorbers so with the new spheres the suspension components will be pretty much completely new. If I find the battery drops the front too much I will individualise the spheres.

This is the battery tray. The photo is a bit old now as I have put most of the front subframe back together again. I will be buying some sheet steel soon to make up the battery box. However with the global chip shortage I can't get the components I need for the BMS system. So that is on the back burner for now while I finish everything else.

Everything like like the charge port. It's not pretty but its functional. The final aesthetics are not really my concern, I'm mostly aiming for a functional EV and the knowledge gained through making it. Other tasks have been stuff like making up coolant line adaptors, reinforcing some mounts that didn't feel strong enough and tidying up wiring.

Right now I'm in the fiddly stage of programming the Teensy Arduino that will run the contactors, gauges and charge cycle. The programming has been a steep enough learning curve as it is. But after that I need to design the PCB board on which it will sit and connect to the various input and outputs of the car.

[talkingcars]

Steady progress.

I had been wondering about how to control mine, I'll have to look in to the Arduino concept.

[LrBen]

Still working on this. We ended up renting out the shed where my MG was stored in September so I had to move it asap. I figured that I should be able put on both subframes and it should be able to at least move without too much work, at least then could get a first drive!

So I did, here is the first drive with electric power back in September.
https://youtu.be/xlf0k4NqK8k
It was a little slow for two reasons, throttle was not adjusted in the inverter and I also had no brakes fitted at that point. This was running on a 60v battery made up of a few cells that will eventually make up the whole battery.
Interestingly I actually used the original throttle body to get the throttle signal for the inverter. All the inverter needs is a variable resistor to map the throttle commands. I will be swapping this to a dual signal throttle position sensor in the final build though, don't want it failing on a wide open throttle signal!

Putting it down onto the rear subframe was a nightmare of a job with jacks and stands, I decided I wouldn't be doing that again. So since september I have been doing up an old 2 post car lift to put into the other shed. Over the Christmas holidays I have just about got it finished and installed. Just waiting on an electrician to put in a three phase line to the lift location.

In the meantime I have also designed and made up the control circuit, as well as the initial code required to work everything. Work is also almost complete on the BMS system needed to manage the battery. This has been delayed by the ongoing chip and general component shortage.

So the next step is to drop the front subframe once more and then install the full battery. Then it will be just a matter of putting it all together properly this time.

[EllsoJo]

This story really caught my eye for 3 reasons:
1. Thought about an electric TF "in theory only" for a few years now, but afraid to try!
2. Bought a TF last year, but it is low-mileage and engine seems fine (Head gasket etc, done,)
3. Noticed you said: "Oh forgot to give a Location in my first post. I'm based in Somerset" I am based near Honiton, but only 16 miles from Taunton. Would be fascinated to see your project "in the flesh". and happy to provide any help I can. (Built a kit car:

many years ago, and did Mech. Eng. before retirement.) PM me if you need an extra pair of hands and/or do not mind a nosey bystander.

Good luck with the project regardless!
EllisoJo

[LrBen]

A quick update on this project. It's not dead!
I spent the first few months of the year testing the BMS system and the charging setup of the Prius Inverter. Using the Prius Inverter to charge from the mains is pretty highly experimental, there are 2 or 3 other people in the world that I know of also trying it. Turns out it's not really that ideal, the setup is far more complicated than using a traditional in car charger and has the potential to short lots of things. Which is what I did, killing my Arduino based VCU in the process. So I decided to switch charging to an Outlander Charger and DC-DC converter. This runs from Canbus and I got it running in a weekend pretty flawlessly.
The BMS system is also being changed out to use Tesla Model s slave boards and an open source BMS system called SIMP BMS that enables communication and control of OEM BMS slave boards.

So allot of months delay but that is the nature of experimenting with new ideas, sometimes they don't go anywhere.

I also decided to change the battery pack location after hearing about the DVLA getting really picky on modifications. If I had to go down the IVA route I would need a certification on my battery box costing around £6,000. So I decided to weld the spare tyre compartment back in and leave the front alone. Instead the battery box will bolt into the passenger seat mounts. Not ideal as it's now a single seater, but that's better than potentially writing the whole project off after it's all finished.

So I currently have the new battery box ready to install, then I need to install the charger in the spare tyre compartment and move the charge socket from the filler cap to somewhere in the front. I have insurance starting from the 30th June so that's my aim for completion.
More updates once it's driving I hope!

3. Noticed you said: "Oh forgot to give a Location in my first post. I'm based in Somerset" I am based near Honiton, but only 16 miles from Taunton. Would be fascinated to see your project "in the flesh".

You are welcome to drop by, give me a private message and we can arrange something. You will probably find some of the other projects quite interesting as well. I'm up near Bath.

[talkingcars]

Pleased you are making progress. What are DVLA saying about battery location?

[LrBen]

Pleased you are making progress. What are DVLA saying about battery location?

It's to do with the requirements for having to get an IVA. Any cutting or drilling of a monocoque body can result in the DVLA/DVSA wanting you to get an IVA in order to register it. This in itself is a small issue, but any IVA undertaken will want to see some certification on the battery box. This is the part that costs £6,000.
Had this been a pre 2001 car, the DVLA are very happy to just change the log book over to electric few questions asked. However currently they are being very difficult with post 2001 cars and changing over the tax class/fuel type. Sometimes they are sending out someone to do a report on the changes, which they then currently ignore anyway as they still don't change anything on the log book. This is what I am worried about, that person could decide that my cutting away of the spare tyre compartment counts as a structural change. So I decided not to risk it.
Were I at an earlier stage on this project I probably would have shelved it, but I decided since I was so close I might as well finish it however I could to take advantage of actually having an electric vehicle.

[talkingcars]

Would it be worth getting an earlier shell and swapping everything over? There are plenty of pre-2001 cars for sale.