# Porsche 924 conversion.



## mike.gamble (Aug 16, 2019)

I'm considering converting my 924 to electric, mainly as I think it would be a good project and potentially make a cracking car?

My main concern is that electrics aren't really my thing, if anything, they are my weakness, especially if I have to try and work out how to wire something up!

I'm competent with greasy and oily things but, this is a big leap for me!

However, I am one of those people if I was told I needed to buy an A, B and C and then wire it up as per this youtube link - I'd be absolutely fine.

However, when it comes to fabrication, this isn't going to be a problem. My best mate who is also quite interested in this project is a professional welder/fabricator so I have access to all types materials and welding techniques.

I'm going to use my '86 924 S as the vehicle that will receive the final fit but, I have an '83 car minus the engine that I am going to use as a test bed to build everything on so I can keep my S on the road and running until I've got a sorted system and am ready to go!

I expect I may have expectations that are unrealistic but, I'd love a car that could do a minimum range of 100 miles and was comparatively as quick as the S (not that quick by modern standards!) but, using a fairly simple system - I read a lot about forklift truck motors being used (?) but, spending a good portion of my budget on buying a good battery pack -Tesla etc so hopefully my range would be realistic?

I'm planning on dumbing down my vehicle, electric windows and mirrors are going and anything else I can get rid of, I will - especially weight which I'm guessing has a direct impact on the range?

At this point in the infancy of my plan, I have a few major questions (for me).

1. My car is rear wheel drive, driven by a torque tube to a gear box at the rear. How much of the original drive train will I need to keep? Do I need a gearbox?

2. How do I mate the new electrics with the existing electrical system in my vehicle? Is it a simple process? Is there benefits to uprating my lighting to LED's to save power? Is there a simple way around having a heater in the vehicle?

3. What bits do I actually need to buy for the conversion? Is it better to buy a ready made kit (not really my thing - I prefer to fiddle!) or can I source everything I need from other (potentially) cheaper sources?

In essence, what do I need to rip out of my project car, what do I need to buy and, is there a wealth of diagrams and videos that will show me how to do the tricky bits?

Cheers in advance for any info!


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## MattsAwesomeStuff (Aug 10, 2017)

> I'm considering converting my 924 to electric, mainly as I think it would be a good project and potentially make a cracking car?


Yes. And a moderately common one I think.



> l receive the final fit but, I have an '83 car minus the engine that I am going to use as a test bed to build everything on so I can keep my S on the road and running until I've got a sorted system and am ready to go!


That's an excellent idea. Very convenient.



> I read a lot about forklift truck motors being used (?) but, spending a good portion of my budget on buying a good battery pack -Tesla etc so hopefully my range would be realistic?


100 mile range is perfectly achievable on a cheap budget. You'll need a 25,000 kwh pack.

Tesla packs are expensive and performance oriented. Not your best bang for your buck.



> I'm planning on dumbing down my vehicle, electric windows and mirrors are going and anything else I can get rid of, I will - especially weight which I'm guessing has a direct impact on the range?


Nope.

And why would you spend all this time converting a vehicle, so that you have a purposefully shittier vehicle to drive?

Weight has a minimal, almost trivial impact on range. Usually when people give rules of thumb for weight vs. range, it's based on the fact that heavier vehicles tend to be larger, and larger vehicles have higher wind resistance, and higher wind resistance is 90% of what costs you energy to keep moving through.

Weight has an impact on acceleration, which is mostly lost in braking (ignore regen, it has little impact), so if you're doing a ton of low speed starts and stops then your range is going to have a little more impact from weight, but otherwise, almost none.

If you can lighten the vehicle by say, half? Maybe go for it.

But to strip out useful features to save at most dozens of pounds? Never. I'd say it literally won't make 300 feet of difference to your range.



> 1. My car is rear wheel drive, driven by a torque tube to a gear box at the rear. How much of the original drive train will I need to keep? Do I need a gearbox?


Wheels, axles, diff - Keep for sure.

Driveshaft/Trans - Up to you.

A transmission is nice to have a physical disconnect in emergency. It also gives you a mechanical reverse (rather than electric reversing). Realistically you don't need a transmission. You have enough torque from zero, and it's a light car, you're probably fine. Just FYI, most EV conversions that leave the transmission just keep the car in 3rd gear all the time, even when starting, and occasionally slip into 4th gear on the highway. They might go weeks or months of daily use without shifting gears. You'll be a little less zippy off the line to kill the trans entirely, but you have more fitment options and less weight if you scratch it.

You'll have to add electric reverse (contactors to flip two big cables) without a trans. If you are doing a super, super cheap build you might want to save a few bucks on those by keeping the trans but, as soon as you're buying batteries the cost of penny pinching elsewhere goes out the window.



> 2. How do I mate the new electrics with the existing electrical system in my vehicle? Is it a simple process? Is there benefits to uprating my lighting to LED's to save power? Is there a simple way around having a heater in the vehicle?


You keep all your 12v electronics, probably even your starter battery just as a reserve. Then you just have a DC-DC converter to buck down from your pack voltage to 12v.

Take all the money you'd spend on LEDs and spend it on batteries.

Headlights are ~150 watts for the pair. Driving highway speed is 15,000 watts. So you'd see literally 1 mile of difference if you could remove the headlights entirely. Less if just converting to LED. Don't bother.

Simple way of having a heater? Use a plug in ceramic space heater from a thrift store. Or use something from a scrap EV. Or plumb waste heat from the speed controller.



> 3. What bits do I actually need to buy for the conversion? Is it better to buy a ready made kit (not really my thing - I prefer to fiddle!) or can I source everything I need from other (potentially) cheaper sources?


1 - Motor.
2 - Controller.
3 - Batteries.
4 - Vacuum pump to run the brakes.
5 - All the little bits and pieces unique to your build, wiring, connectors, etc.

You can buy something like a kit for 10x the cost and you'll still have to do a lot of custom work to it.

Motor will be nearly free. Controller you'll have to build or buy, $500-$1000. Batteries you'll have to buy (a few thousand).

This is very doable for someone with little or not electrical knowledge.


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## mike.gamble (Aug 16, 2019)

Firstly, thanks for the info and the time taken to write it!

Re the transmission, I know this is probably a bit of an obvious question but, if I remove the gearbox and torque tube, I’m assuming that the electric motor will then be fitted somehow directly to the diff?
If so, I take it that it’s just a case of fabricating an adaptor plate to mate the two parts?
Re the reverse, it sounds simple enough to have a switch for reverse but, I’m not missing anything there am I? It’s just a case of flicking a switch and I’ll be going backwards?
If I have got things right and the motor was mounted at the rear, I suppose the obvious choice would to be to put the batteries up the front, somewhere in the void left by the engine - along with all the ‘new’ electrics?

I thought it would be a sensible option to go for the Tesla batteries as I was under the impression that they were the best available but, with regards to your comments, what battery system would you recommend?

I’m UK based but I although there will be some variation in EV models available here, I’m guessing a lot of manufacturers ‘share’ so I should be able to get something similar to your recommendations?

The controller. You mentioned making one - that sounds a little bit electrical and potentially difficult? Is it simple enough to do or should I save myself the pain and buy one?

Finally, before I go off and do more research, what motor would you recommend? If I’m being honest, I would like some performance but, I need to balance this against range. It’s pointless to have a road-rocket that only has a range of 30 miles but conversely, I don’t want to drive a slug for a 100 miles!! 
I can start looking at motors now as I’m guessing that it’s going to be the first step, getting it mated up correctly.


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## mike.gamble (Aug 16, 2019)

This is the engine bay on the test car. I started ripping the engine out today. I’m trying to sell on as much as I can to help finance the purchase of some of the bits needed for my conversion!!


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## MattsAwesomeStuff (Aug 10, 2017)

mike.gamble said:


> Re the transmission, I know this is probably a bit of an obvious question but, if I remove the gearbox and torque tube, I’m assuming that the electric motor will then be fitted somehow directly to the diff?


Depends on the suspension, of which I'm a novice at understanding so I can't be too specific.

You might need a pair of U-Joints to handle misalignment.

The bigger concern is whether you can actually fit a motor there, and whether the 924 has room, or you are okay with making room by modifying the underside of the body. And, perhaps clearance issues too. But if you can make it work it'd be a nice setup.

You could buy a replacement rear end from a salvaged OEM EV, but there's lots of fitment issues there too to troubleshoot. And it's probably out of your dollarstore budget.



> If so, I take it that it’s just a case of fabricating an adaptor plate to mate the two parts?


That will be needed regardless of what you're mating to what. Brackets and mounts and things to hold things to other things.



> Re the reverse, it sounds simple enough to have a switch for reverse but, I’m not missing anything there am I? It’s just a case of flicking a switch and I’ll be going backwards?


Electrically, it's very simple.

On a DC motor, all it's doing it taking positive and negative, and swapping places.

In order to do that, you need an electromechanical switch for each wire, which both switch at the same time. This is just a part you can buy, it's a Double-Throw-Double-Pole contactor (a contactor is a big relay). But to get one rated for big enough voltage and current is a bit expensive (high dozens of dollars at least).

To make the contactor toggle, you just control it with a small switch, anything will do.

If you want to go with a really ghetto setup, (as in, you want to save every dollar and do the bare minimum to make the vehicle functional at first), you could make your own switch from chunks of copper or a wallet-sized plug that you pull out and put back in backwards every time you want to change direction. You're (hopefully) never changing from forward to reverse and back when there's any power flowing, so, it's pretty simple in design. Depends on your priorities though.



> If I have got things right and the motor was mounted at the rear, I suppose the obvious choice would to be to put the batteries up the front, somewhere in the void left by the engine - along with all the ‘new’ electrics?


It's a unique challenge to each vehicle. Generally yes. And, even if you (honestly, likely) mount the motor up front still, a motor is going to be way smaller than an engine, so, batteries will still probably go up front. Maybe a few more wherever the gas tank used to be. Under seats are another popular option. Wherever you can stuff them basically.



> I thought it would be a sensible option to go for the Tesla batteries as I was under the impression that they were the best available but, with regards to your comments, what battery system would you recommend?


You have to go to a scrappers to have a chance at doing this affordably. And then the answer is, anything. Literally any OEM EV vehicle battery pack is fine for you. Form factor is probably something to consider (different models have different shapes and sizes that will be more or less suitable to you).



> The controller. You mentioned making one - that sounds a little bit electrical and potentially difficult? Is it simple enough to do or should I save myself the pain and buy one?


You don't design one. You buy plans and follow instructions to build one, or a kit. (Or maybe find someone who built one but never finished their project). A DC power supply is pretty straight forward. If you can build a LEGO set and smoke a cigarette without lighting your eyeballs on fire, you are qualified.



> Finally, before I go off and do more research, what motor would you recommend? If I’m being honest, I would like some performance but, I need to balance this against range.


A forklift motor. There's a gigantic thread stickied at the top of the Motor subforum.

Basically, chances are any old forklift motor you pull yourself is going to cost you a couple hundred bucks (scrap value), and you'll want to make sure it's roughly the right size (usually diameter is the lingo), with decent brushes, and, obviously the right type. You take a spare car battery and some jumper cables, maybe a chunk of wire with you to spin it up and test it. Most shops will have a shelf in the back of a few "just in case" motors but the other 99% of them get hauled off for scrap.



> I can start looking at motors now as I’m guessing that it’s going to be the first step, getting it mated up correctly.


Yep. You're probably looking for something 11" in diameter. There's not a lot of variation. Chances are the first mid-sized junk forklift you see will have a suitable motor. If you're unlucky you might have to poke around 3 or 4.


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## Tremelune (Dec 8, 2009)

You'll need a way to charge the batteries, which involves a charger, a battery management system (BMS), controller(s) for them, and some display to tell you the state of charge and what not. Thunderstruck sells this stuff, as well as Orion. Total cost will likely run over $2k.

You'll want to keep your transmission, as a lot of these forklift/aftermarket electric motors have redlines of around 3,000 RPM (OEM motors spin much faster). The sticky wicket with the 924 is that the transmission is in the _rear_ even though the motor is in the front. That's rare. I don't know how the engine couples with the torque tube, but it might just be similar to any other bellhousing.










All that said, you might want to look into ditching the whole transaxle and torque tube and putting something like a Nissan Leaf motor (with 8:1 reduction gear intact) in the rear. You would need custom axles, and a way to mount the motor to the car, but the rest is finding locations for the other components, and wiring more or less.

If I were you, I'd leave the rest of the car intact and unmodified as much as possible.


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## mike.gamble (Aug 16, 2019)

To remove a few possible options to make the path slightly clearer, if I decide to start using axles etc from other EV vehicles, I’m probably going to fall foul of some of the registration legislation here in the UK regarding modifications and make my life exceptionally painful!

In light of this I will have to use the (major) components as fitted. This does in some way, clarify my path.

Re the 924 set up, yes, the torque tube essentially has a bell housing on that mates to the engine so, if it utilised the torque tube and gearbox, it wouldn’t be too much of an issue to mount the motor at the front.

I’ve had a look on eBay today at electric forklift motors and there seem to be only a few for sale (maybe I just searched on the wrong day?) but, loads were available from the U.S.
Maybe we do forklifting differently here?! Apparently most of them run on LPG?

Anyway, I found a reconditioned one with the following spec. It it the sort of thing I should be looking at?

Motor Specs

Power 5KW

Voltage 48v fed from a logic controller

Current 157A

Rated speed 1500 rpm

Maximum speed 4500 rpm

Frequency 75 Hz

Cos 0.72

Service S2 60

Insulation class F

Protective Degree IP10

Bearings 6206 2RS

weight 38.5kg

As ever, many thanks for your help!!


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## brian_ (Feb 7, 2017)

As I suspect you now understand, there is no way to remove the transmission without removing the differential (because they are both within the transaxle), so connecting a motor directly to the original differential is not an option.

It would be beneficial to keep the motor out of the engine compartment, because you need space for battery and the motor both takes space and is heavy. If the entire transaxle is retained, but the torque tube is removed, it would be great to put the motor directly on the from of the transaxle; unfortunately, there isn't enough space for a motor (especially those old "forklift" brushed DC motors) between the transaxle and the torsion bar housing of the rear suspension.

For more discussion of 924 configuration options, I suggest reading the other recent 924 discussion in this forum.
https://www.diyelectriccar.com/forums/showthread.php/showthread.php?t=201041&amp=1


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## brian_ (Feb 7, 2017)

Matt's suggested battery capacity of "24,000 kWh" was, of course, supposed to be just 24 kWh, or 24,000 Wh. For perspective, this is the capacity of an early Nissan Leaf pack; new production EVs tend to have 40 kWh or larger capacity.


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## x.l.r.8 (Oct 20, 2018)

I think you will find the other post you referred to is the same OP just trying to move the discussion to an appropriate section of the forum


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## x.l.r.8 (Oct 20, 2018)

I’m not sure you could not fit a motor onto the transaxle. I’m pretty intimate back there on 924’s and you will have to support the transaxle once you remove the torque tube. Depending on if you intend to keep the non functional rear seats you may find a slight rotation in the transaxle will accommodate the forklift motor. It’s not a route I chose so I never thought about measuring up for that but there is a fair amount of room and a plate to a transaxle that already has a spline coupler is a rare treat.


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## brian_ (Feb 7, 2017)

x.l.r.8 said:


> I think you will find the other post you referred to is the same OP just trying to move the discussion to an appropriate section of the forum


LOL
I didn't check the member name, because the questions seemed like they were from someone who had not been in the previous discussion.


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## brian_ (Feb 7, 2017)

x.l.r.8 said:


> I’m not sure you could not fit a motor onto the transaxle. I’m pretty intimate back there on 924’s and you will have to support the transaxle once you remove the torque tube.


I (still) agree with the space concern.

One way to address the support issue is to replace the torque tube with a beam (all the way to the battery box structure, or to a convenient intermediate location). The situation is similar to the Miata, which has a Power Plant Frame performing this function.


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## mike.gamble (Aug 16, 2019)

I’m still struggling to find an electric motor over here but, this has just popped up on eBay, would it be suitable - I know nothing about what would make a good donor motor!!!


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## mike.gamble (Aug 16, 2019)

I’ve tracked a breakers down who have a few motors available and I’m going to give them a call tomorrow and hopefully, finally get my hands on a motor!

However, I don’t really know what I’m talking about - what do I need to ask?

Everyone seems to mention the size - 11” motor etc and I’m guessing I want a 48v DC but when it comes to the max rpm, do I need a certain or, minimum rpm speed?


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## MattsAwesomeStuff (Aug 10, 2017)

mike.gamble said:


> Everyone seems to mention the size - 11” motor etc and I’m guessing I want a 48v DC but when it comes to the max rpm, do I need a certain or, minimum rpm speed?


Knowing the context of where they were used, you're probably fine to just pick a general motor. The specs are going to be in the same ballpark.

What you want to look for are brushes and a commutator in good shape.

You'll want 4 terminals accessible. You'll want it to be a series-wound motor. 

Show up with a spare car battery and some jumper cables, and a jumper wire (to connect between coils that your jumper cables aren't on). Make sure it spins. If it squeels, not a big deal, you'll want new bearings anyways and a bearing set is $20.


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## evric (Oct 26, 2008)

If I were you, I would use one of the new Netgain Hyper 9 AC motors.
This will give you regen and especially no brushes to wear out.

These come as kit complete with controller, meter, foot pedal, contactor and LV wiring.

It would be a lot more expensive that a fork lift motor, but much better in the long run.

Simple replace the ICE with the AC motor, leaving the rest in place.


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## Duncan (Dec 8, 2008)

evric said:


> If I were you, I would use one of the new Netgain Hyper 9 AC motors.
> This will give you regen and especially no brushes to wear out.
> 
> These come as kit complete with controller, meter, foot pedal, contactor and LV wiring.
> ...


A Porsche with a wimpy Hyper 9 - !!!


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## Tremelune (Dec 8, 2009)

I mean...The 924 put out under 100hp...The Netgear would double the torque...The problem is that they cost thousands.


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## brian_ (Feb 7, 2017)

Duncan said:


> A Porsche with a wimpy Hyper 9 - !!!


More like a VW/Audi ... but yes, even though base 924 was not powerful, it would be nice to do better than a HyPer9 could.


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## remy_martian (Feb 4, 2019)

1) The 5kW motor spec will get you a premium sports car brand golf cart. Did you mean 50? Even that is a bit lame for a Porsche, IMO.

2) MattsAwesomeStuff's statement of weight not mattering for range is because he, apparently, builds hovercars. For the rest of us, weight directly affects rolling resistance, which DOES affect range (to wit Teslas with varying rolling resistance tires, Model 3 vs Model X range, etc).

3) A torque tube arrangement is not that unusual -- Corvettes have had it for a couple of decades. You do realize, with that setup, that you can delete the engine location (to make room for batteries) and driveshaft (the tube itself might be structural...if so, you'll need to fab a shorter, possibly stiffer, tube in its place and affix the front and back to the chassis) and attach the colocated motor to the differential/gearbox? Edit: this point has already been mentioned in more detail - I just read that posting


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## MattsAwesomeStuff (Aug 10, 2017)

remy_martian said:


> 2) MattsAwesomeStuff's statement of weight not mattering for range is because he, apparently, builds hovercars. For the rest of us, weight directly affects rolling resistance, which DOES affect range (to wit Teslas with varying rolling resistance tires, Model 3 vs Model X range, etc).


You can try to misquote me to make what I said sound less reasonable, but, I stand by what I said. In fact, might as well just requote it if you're going to say it doesn't apply:

"Weight has a *minimal, almost trivial impact on range*. Usually when people give rules of thumb for weight vs. range, it's based on the fact that heavier vehicles tend to be larger, and larger vehicles have higher wind resistance, and *higher wind resistance is 90% of what costs you energy* to keep moving through.

Weight has an impact on acceleration, which is mostly lost in braking (ignore regen, it has little impact), so if you're doing a ton of low speed starts and stops then your range is going to have a little more impact from weight, but otherwise, almost none.

If you can lighten the vehicle by say, half? Maybe go for it.

But *to strip out useful features to save at most dozens of pounds? Never. I'd say it literally won't make 300 feet of difference to your range.*"


So, which of those assertions I made is wrong?

Give an estimate on how much range he's going to be adding by stripping out power windows and other car features.

When traveling at highway speeds, which is what people have range anxiety about (no one travels hundreds of miles inside the city in a day, and thus range is moot when you recharge at night)... what percentage of your range is made up of rolling resistance?

http://www.enginuitysystems.com/EVCalculator.htm

Looking up the numbers for a 924 and punching those in... 1000kg, 70mph, 1.8m^2 frontal area, 0.32 coeff of drag, 0.01 coeff of rolling resistance (wiki says typical of car tire on concrete)... I'm getting:

18.7hp total to maintain speed.
14.6hp overcoming aero forces
4.1 hp overcoming rolling resistance

Even then, I was wrong. That's ~22% rolling resistance on an especially small car with low wind resistance, not 10%. Much higher than I expected.

Now let's look at his choices.

Call it 2200 lbs. How much weight is he going to be stripping by replacing window motors with cranks, removing the mirrors, etc?

20lbs to be generous? Shoot way high and call it 40lbs?

20-40lbs is 1-2% of vehicle weight, which has linear affect on 22% of range. So, 0.002-0.004 of range. So, I was wrong. It makes 1000-2000 feet of difference to the range, not 300 feet.

If I proposed: "Would you give up less than a quarter mile of range, to add power windows, mirrors, etc to your vehicle?" ... how many people would turn that down?

Reversed, how many people would you suggest to strip features off a car to gain less than 1/4 mile of range?

My wild assed guess was in the right ballpark, I think it's a reasonable claim.


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## remy_martian (Feb 4, 2019)

Not everybody is blasting down the road in a brick at 80MPH. As Cd goes down, rolling resistance becomes significant.


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## MattsAwesomeStuff (Aug 10, 2017)

remy_martian said:


> Not everybody is blasting down the road in a brick at 80MPH.


I picked a reasonable 70mph, not 80, plain to see above, y'know, where I said 70 miles an hour.

And I picked the actual numbers for a small, sleek Porsche 924, not a brick or a cube van.

So, my numbers above are the actual numbers for the actual vehicle at the actual speeds it would be travelling. 22% is rolling resistance. 20-40lbs of features trimmed would result in about 1500 feet of range increase. Do suggest whether you think it's a good idea to start ripping features off the car to improve range. I would not suggest that.



> As Cd goes down, rolling resistance becomes significant.


As Cd goes down, range becomes less significant, because no one cares about their range unless they're on the highway. No on other than taxi drivers and cops can put anything threatening a 100 mile range on their vehicle in a day.

Context matters.


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## mike.gamble (Aug 16, 2019)

Most of that went over my head....

Anyway, I’ve reached a point where I need to start getting my finger out and getting a motor bought.
Regardless of opinions and thoughts, the electric motors do seem rare here in the uk. 
I can find nothing locally and have been to 5 scrapyards and a specialised machinery breaker with no luck so, it eBay!!

These appear to be my two options;

item number 132135830868 or, 123722219059.

The final option is to buy a complete vehicle/item (?) so, what are the thoughts on this which isn’t a million miles away from me in the grand scheme of things?

163786139563

Any thoughts gratefully received - unless someone wants to ship me one from the US?!


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## mike.gamble (Aug 16, 2019)

Anyone? 
I’m quite nervous about buying a motor without being told it’s right!!


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## MattsAwesomeStuff (Aug 10, 2017)

First one is an 8.5" motor, 12" long. It's probably too small for what you'd want.

Second one my first thoughts were "How gigantic was that sharpie?". Here's the specs, maybe, I dunno: http://parts.forkliftfocus.nl/electrical-motors-parts/driving-motor-for-still-fm-20.html -- 5.2kw. ... He says it's from a Still FM 20. If you just look up what a "Still FM 20" is... it's barely even a forklift. It's almost a walk-behind. I suspect this motor is even smaller than the first.

The third one I would not buy, too small.

I think you need to get a hold of some of the older UK members for their recommendations. I asked a couple of them if they think the industry has changed and if they have different advice. I'll let you know what they said.


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## brian_ (Feb 7, 2017)

mike.gamble said:


> I can find nothing locally and have been to 5 scrapyards and a specialised machinery breaker with no luck so, it eBay!!
> 
> These appear to be my two options;
> 
> item number 132135830868 or, 123722219059...





MattsAwesomeStuff said:


> ...
> Second one my first thoughts were "How gigantic was that sharpie?". Here's the specs, maybe, I dunno: http://parts.forkliftfocus.nl/electrical-motors-parts/driving-motor-for-still-fm-20.html -- 5.2kw. ... He says it's from a Still FM 20. If you just look up what a "Still FM 20" is... it's barely even a forklift. It's almost a walk-behind. I suspect this motor is even smaller than the first.


Not a big marker - just a small motor. Look at the size of the bolt on the bracket relative to the motor. It's only a steering motor, not a traction (or even pump) motor. Maybe for a go-kart, but not a car.


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## brian_ (Feb 7, 2017)

mike.gamble said:


> The final option is to buy a complete vehicle/item (?) so, what are the thoughts on this which isn’t a million miles away from me in the grand scheme of things?
> 
> 163786139563


eBay UK item 163786139563: Bradshaw T10 Electric Vehicle Car Tow Truck

I don't know how helpful this is, but you're not the only one looking at a Bradshaw T10:
Any help identifying this motor?


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## MattsAwesomeStuff (Aug 10, 2017)

brian_ said:


> Not a big marker - just a small motor.


_that's the joke..._


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## mike.gamble (Aug 16, 2019)

I've spent another few hours today removing various parts and getting ready for the engine to be removed.

One thing I have noticed - and it's obvious when you think about it - how much weight is being removed from the car my the surplus items!

The exhaust, starter motor and alternator plus a few other bits were removed and the combined weight soon adds up.

I'm guessing when I fit all the EV parts, there will be a reasonable weight added to the vehicle but, generally, would the vehicle wind up significantly lighter after being converted?

Before I started removing too much weight and the engine, I measured the location/height of the front torque tube housing so, when I have the engine out and the DC motor fitted, I'll be able to ensure everything is aligned correctly.

I've been pondering how to remove the defunct wiring looms required for the ICE without causing any problems so, I'm going to just slice open the looms, remove the wiring back to the fuse box and then re-seal the remainder of the wiring - I'm guessing that should be ok?

I'm going to remove the fuel tank as well which looks like it could be a pig of a job but, it could yield space to locate some of the new electrics or, even the batteries?

However, still struggling to find a suitable motor, here in the UK.
I have been genuinely pondering buying one from the US as although I'll get hammered on shipping, it may prove to be the easiest way to go?

I've got one last avenue to try over here - a friend works for one of the railway companies so, he's going to see if they use anything useable in any of their lifting equipment or, in any similar machinery?

Are there any 'specialists' who deal in these motors in the US that someone could point me in the right direction of?


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## evric (Oct 26, 2008)

Before you remove any wiring, I would suggest that you label every wire/connector to show where it came from and leave them all in place while you convert the car. You may find another use for the wires later and this will save you running a new wire for a new purpose. Once the conversion is complete, that is the time to tidy up the wiring looms.


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## brian_ (Feb 7, 2017)

mike.gamble said:


> I'm guessing when I fit all the EV parts, there will be a reasonable weight added to the vehicle but, generally, would the vehicle wind up significantly lighter after being converted?


Generally, no, it will not be lighter at all. If they have comparable performance and significant range, EVs are heavier than the corresponding gas-engine car - usually substantially.

Yes, the engine is heavy, but so is the motor and the battery is much heavier than a tank of fuel. And those supporting systems weigh a lot, but EVs have them, too... controller, charger, lots of wiring and switching components, even a cooling system in modern EVs.

For examples, look at current production EVs and their gas counterparts, such as the Nissan Leaf and Versa, or the EV and gas versions of the Kia Soul, VW Golf, Ford Focus, Fiat 500, etc. I haven't looked at all of them, but there is generally an increase.


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## mike.gamble (Aug 16, 2019)

evric said:


> Before you remove any wiring, I would suggest that you label every wire/connector to show where it came from and leave them all in place while you convert the car. You may find another use for the wires later and this will save you running a new wire for a new purpose. Once the conversion is complete, that is the time to tidy up the wiring looms.


Good point, I never thought of that. I’m so focused on removing everything!!


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## dtbaker (Jan 5, 2008)

mike.gamble said:


> I'm guessing when I fit all the EV parts, there will be a reasonable weight added to the vehicle but, generally, would the vehicle wind up significantly lighter after being converted?


My eMiata build came out almost exactly stock weight when I was done.... but double the torque, 







mike.gamble said:


> I've been pondering how to remove the defunct wiring looms required for the ICE without causing any problems so, I'm going to just slice open the looms, remove the wiring back to the fuse box and then re-seal the remainder of the wiring - I'm guessing that should be ok?


don't waste your time doing this..... you may reuse many of the disconnected circuits. i.e. the fan circuit is great to use for your controller coolant pump.






mike.gamble said:


> I'm going to remove the fuel tank as well which looks like it could be a pig of a job but, it could yield space to locate some of the new electrics or, even the batteries?


yes absolutely get that out!
usually a good place for batteries, just make sure you can get to them when you are done when you need to check cell voltages and 'balance' manually...unless you have a very sophisticated and trustworthy BMS planned.



mike.gamble said:


> However, still struggling to find a suitable motor, here in the UK.
> I have been genuinely pondering buying one from the US as although I'll get hammered on shipping, it may prove to be the easiest way to go?


the most popular DC motors are basically forklift motors. The Warp9 from Netgain for instance. I'm sure you can find similar in UK and avoid VAT and shipping.


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## Boxster-warp (Jun 22, 2014)

Hello 
I have a new netgain warp 11 engine. Wanted to install it in a Porsche boxster, but now I would rather take a beetle. There the engine is too big for. 

I paid 3000 € 4 years ago. I have no pictures because the engine is still in a company. Shipping from Germany to England is certainly not cheap for the 100 kg monster.
I would rather use a netgain 9 for myself. 
Maybe that would be interesting for you. Otherwise, I have to get the engine somehow in the beetle.

Greetings Boxster-Warp


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## Duncan (Dec 8, 2008)

As far as the weight is concerned a good rule of thumb is that 

You lose a lot of weight changing the dino burner bits for electric 
The weight loss however is cancelled out by the batteries

At somewhere around 70 miles of range the batteries cancel out the weight loss - and if you want more range the car starts getting heavier again


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## mike.gamble (Aug 16, 2019)

I haven’t disappeared - I’ve just been very busy trying to track down a suitable motor which, does appear to be the main issue here in the UK - although I have no idea why it has turned into a challenge!

However, I have spoken to a fork lift dealer about 100 miles away who say they have half a dozen old electric forklifts that they will be scrapping at the end of the month but, they’re happy for me to did through what they have and pick up what I need!

Once again, I’m after any tips or pointers re selection of the correct motor and also, is there anything else that I could pick up that would come in useful later?


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## Duncan (Dec 8, 2008)

Hi
You want DC motor with four sets of two brushes - either 9 or 11 inches in diameter
about 60 kg or 100 kg

It must have a male drive shaft - not a female

I like the splined shafts

Some motors have double ended shafts with a parking brake on one end - grab that it will have a female spline bit to match the male splines on the motor

If you are going direct drive grab the biggest reversing contactor
The other contactors may also be handy

If they are letting you have the motors for scrap metal prices and will otherwise scrap them off grab a couple of extras - may be useful as spares or to swap for something else you need 

Take a trailer - you do not want four or five dirty heavy motors in your car


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## mike.gamble (Aug 16, 2019)

Cheers! Is there a specific rpm range I should be considering and I’ve seen some 48v and 72v motors around? Is either more preferable?


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## Duncan (Dec 8, 2008)

In the forklift they will be doing about 1500 rpm

You will be feeding them more volts and using higher rpm's

I'm using a Hitachi 11 inch motor - it's 48v and 10 KW - 1400 rpm
When I was feeding it 130v it would only do 3500 rpm in my car - 100 kph

Feeding it 144v however was fine

(I'm now feeding it 1200 amps and 340v - and I have taken it up to 5300 rpm)

I would worry that a 72 volt motor may need too high a voltage to get the revs you need


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## mike.gamble (Aug 16, 2019)

Gents, I may have found something suitable and was just hoping for the thumbs up?
It’s a Daewoo 7.5kw 48V motor with a part number of 954/a164332 if anyone could give me a yay or a nay?


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## mike.gamble (Aug 16, 2019)

I’ve missed out in this motor but, still looking and, I’ve tracked down a forklift dismantlers about 250 miles away that say they can definitely help.
I’ve just messaged them with the spec I’m after and am now waiting for them to get back to me.
I’ve also invested in a ‘how to convert your car to electric’ manual for so exciting pre bedtime reading!
Hopefully I’ll start moving forward at some point!!


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## mike.gamble (Aug 16, 2019)

While my quest for a motor continues, I thought I cut up one of the other 924 shells I have and have a good look at the feasibility of mounting some of the batteries under the boot floor.
The depth from the top of the boot floor to the top of the gearbox isn’t as deep as I expected but, I think I could probably build a carrier that was deeper on the sides of the transmission.
It there great variety in sizes and dimensions of the various battery packs that I’ll be able to pick up from a damaged car?


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## brian_ (Feb 7, 2017)

mike.gamble said:


> While my quest for a motor continues, I thought I cut up one of the other 924 shells I have and have a good look at the feasibility of mounting some of the batteries under the boot floor.


It is certainly convenient to have multiple body shells to work with. I have often thought that by the time someone has completely torn apart and understood a vehicle for a conversion, they will likely have destroyed one body shell, and they probably know enough to do a couple of different styles of conversion of that model.



mike.gamble said:


> The depth from the top of the boot floor to the top of the gearbox isn’t as deep as I expected but, I think I could probably build a carrier that was deeper on the sides of the transmission.


My understanding is that is the fuel tank location. You just have to look at the tank shape, which has a flat top (against the cargo compartment floor, which has been cut out of this body) and drops down on each side of the transmission, to see what volume is available and how it is shaped. Unfortunately, prismatic cells are rigid rectangular blocks which don't pack well into spaces like that, pouch cells are flat rectangular pouches which only work reasonably when stacked into larger rectangular boxes, and little cylindrical cells take an enormous amount of fabrication work to assemble into functional modules.

Here's a tank sitting - upside down - in the cargo space above where it gets mounted, borrowed from a blog about the fuel tank showing which shows its shape and size:








The big dent in the middle is where it fits over the rear end of the transmission.

I had not seen a 924 spare tire well before - that's hilarious.  Apparently the well is sized and shaped for a full size tire sticking way up into the cargo space, and the stock spare is a collapsible thing that tucks down in the well (diagonally) so it doesn't stick up... until you have a flat and need to put the flat tire in there. Just looking at the bare body I first wondered why they didn't set the spare flat, extending forward over the transmission (and resulting in a big bay for battery)... then I realized where the fuel tank goes.



mike.gamble said:


> It there great variety in sizes and dimensions of the various battery packs that I’ll be able to pick up from a damaged car?


There is certainly variation. You won't be able to fit an entire pack, but you will be able to mount modules salvaged from a production EV, in a different arrangement than used in car designed to fit them. All modules are rectangular boxes, but they vary in proportions, and their size depends on both the total battery capacity and the number of modules it is split into. Some of the smaller modules are from the Nissan Leaf, because the original version splits 40 kWh or less of capacity into 48 modules (and a later updates bonds those together in pairs for 24 twice-as-tall blocks); the largest that I've seen are from the Tesla Model 3, which puts up to 75 kWh of capacity in only four very long and substantially wide modules.


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