[MattsAwesomeStuff]

Mostly just reiterating what everyone else has said:

• Your car is very light
• Your motor is quiet small
• Your motor is maybe barely okay for that car, but generally anything under 9" diameter is in the realm of Golf Kart or Motorbike. Usually 7", 8" is a weird size no one uses.
• Your car will need ~15kW to maintain highway speed.
• You usually want double that power to account for reasonable drive-like-a-normal-person acceleration and not hold up traffic like a cyclist
• You would want double that power again to account for that kind of acceleration up a hill, including raised onramps (where also accelerating).
• Unless you're trapped on a desert island, the lack of motor bearing (never seen that before in hundreds posted) is a dead end, find another motor, that's weird.
• 11" motor is probably overkill for a 2300lb car unless you're after performance. It'll weigh ~250lbs, and you'll want that weight for batteries instead
• 9" motor is probably what you actually want 125-175lbs-ish
• You can exceed motor plate ratings significantly because you'll have non-zero air cooling
• You can exceed motor plate ratings even more because if you actually use that amount of power, you'll self-restrict to a short run time because you'll run out of battery before your motor heats up enough.

 

[muidsa121]

You usually want double that power to account for reasonable drive-like-a-normal-person acceleration and not hold up traffic like a cyclist

So is that 15kw+15kw =30kw for hills?

 

[remy_martian]

Barely...yes.

 

[muidsa121]

Barely...yes.

Wow... I now understand why you said to jump straight to ex ev parts...

 

[MattsAwesomeStuff]

So is that 15kw+15kw =30kw for hills?

No.

• 15kw to maintain highway speed.
• 15kw x 2 = 30kw to have comfortable acceleration, or to maintain highway speed up a hill.
• 30kwh x 2 = 60kw to have comfortable acceleration up to highway speed up a hill

Though keep in mind, you're only accelerating for, what, 10-20 seconds until you've reached highway speed, after which you're only needing the maintenance speed.

Honestly if you have high enough voltage and punch it, your 8" motor could probably do 60kw. But it would be equivalent abuse to Duncan doing a drag race pull on his 11".

9" would be comfortable with it.

I wouldn't put the time in on a marginal solution, just grab a 9" motor.

 

[muidsa121]

No.

• 15kw to maintain highway speed.
• 15kw x 2 = 30kw to have comfortable acceleration, or to maintain highway speed up a hill.
• 30kwh x 2 = 60kw to have comfortable acceleration up to highway speed up a hill

Though keep in mind, you're only accelerating for, what, 10-20 seconds until you've reached highway speed, after which you're only needing the maintenance speed.

Honestly if you have high enough voltage and punch it, your 8" motor could probably do 60kw. But it would be equivalent abuse to Duncan doing a drag race pull on his 11".

9" would be comfortable with it.

I wouldn't put the time in on a marginal solution, just grab a 9" motor.

Noted... My project now looks feasible again.... Thanks GUYS

 

[remy_martian]

It always was, just that you were picking puny motors for the job 😛

 

[Duncan]

That would be from 300 km to 400 km - that is a LONG range for a DIY electric car

 

[remy_martian]

We were only talking motors, not battery capacity...

 

[Duncan]

We were only talking motors, not battery capacity...

The two go together - if you have the battery capacity to do things for a long time then you need the motors able to do that without melting -

 

[piotrsko]

400 clicks, so Delivery vehicle? Then pretty much anything over 9"series, most of the traditional inductions, but now battery size becomes a problem

 

[muidsa121]

That would be from 300 km to 400 km - that is a LONG range for a DIY electric car

400 clicks, so Delivery vehicle? Then pretty much anything over 9"series, most of the traditional inductions, but now battery size becomes a problem

How So?

 

[remy_martian]

The two go together - if you have the battery capacity to do things for a long time then you need the motors able to do that without melting -

Still not following.

30kW motor.

Lowball example: 65Ah cells, running 3C, 38 of them for 144V.

That's 20 minutes at 100km/h or 33km range using 0-100% SoC. No motor melting, an FB-4001 is running at nameplate.

How do you land at 300km range from a motor discussion???

Why do you say the motor will melt?

90% of people want something to drive on a road - almost nobody does what you're doing because motor melting/failure is not acceptable like it is for you.

I'm trying to understand how you arrived at 300km range from a 30kW motor need with zero discussion of battery.

 

[Duncan]

I'm trying to understand how you arrived at 300km range from a 30kW motor need with zero discussion of battery.

"I just need it to do 60-80kmh for 5 hours, every 2 weeks..." f

I was replying to this requirement - from from muidsa121

 

[remy_martian]

ah...got it. thanks

It's unclear that he needs the 5 hours in one shot, but it's his wallet that pays for the batteries, both up front and in carrying dead weight around, if he only drives the cars an hour at a time.

 

[djbills]

If it's helpful, I run my 81 124 Spider with an 8" ADC (essentially similar to a netgain warp 8, I think, if you can't find ADC specs - it's a 203-06-4001 if memory serves).
It's running at 156v (a little hotter than usual, essentially because my that's what my controller maxes out at) and really seems to be the sweet spot in terms of everything. It's a little underpowered on steep grades, but some of that is to be expected when using these lower voltages. Pretty peppy the rest of the time, I mean it's no tesla but it will respond if I get into the pedal and definitely puts the power in the 0-40mph range, feels very snappy before it trails off and probably starts to lag behind what an ICE fiat would be doing. The 8" at that voltage feels like a good mix of power and rpm vs weight/size.
I think Valeri runs an 11" in his 124 conversion down in LA - which is a monster! I'd be interested to hear his opinion (maybe if you look him up on ev album and contact directly).
I've had both a 7" prestolite and an old 9" GE in my other microvan (a 144v jet electravan, which is a subaru 600) and honestly the 7" right now feels a little underpowered (but better shift points), but the previous 9" was overkill, and seemed too far the other direction in terms of being a heavy motor that made things kind of sluggish. If I ever came across a low cost warp 8 or similar for the van, I might give it a go. Maybe the 8 is just perfect for my area and weight class.
So, maybe that's helpful? You could at least look up the specs and get an idea from another Spider driver who's sort of already been through it. The 8" is really nice! Maybe a 9" (and perhaps more volts) could be helpful if engineering for an area that is more hilly. There's definitely another inch or 2, mounting wise, even with batteries up front and back. I'm not sure how the 11" fits down there, probably a much different design.
I know there is a range of 8" motors and the diameter is only part of the story, but the specs are online.
here's mine: J Bills' 1981 Fiat 124 Spider

 

[djbills]

oh and goes without saying, if I can help you in any way... just say the word. Photos, diagrams of trans adapters etc.
there are only 3-4 of us crazy enough to convert a 124 out there, gotta stick together.

 

[piotrsko]

So back to the OP: exactly what are YOUR specific needs here? As you can see, our replies are going to be all over the place based on OUR designs which are based on OUR needs.

so this periodic long distance trip: one shot or can you stop, city or country driving, flat or hilly, and is this the only parameter or will you do lesser trips between?

 

[jbush]

So back to the OP: exactly what are YOUR specific needs here? As you can see, our replies are going to be all over the place based on OUR designs which are based on OUR needs.

so this periodic long distance trip: one shot or can you stop, city or country driving, flat or hilly, and is this the only parameter or will you do lesser trips between?

Thanks for all of the responses, this is helpful! It's nice to see a few other 124 conversions mentioned here.

The 124 wasn't a super high performance car. I have a '78, which came with a non-fuel-injected 1.8L engine, generating out about 84 hp and 90 ft-lbs of torque. My first requirement is something that works . In all seriousness, perfect is the enemy of the good, and my primary aim is to have a fun project and learn about cars. I want to get something I can drive around and not just have a hunk of metal sitting in the garage. Ideally, this would be something that is fun to drive and peppy for short trips around town on level ground.

My original plan was to use a LEAF motor with the EVBMW control board in a Prius inverter. This seemed to be a good compromise between performance and cost, and there was something amusing about putting Frankenstein components from two kinda boring cars in an Italian sports car. Alas, I got the EVBMW board web interface working, but it is very finicky and keeps reporting errors, so I ran out of patience with it.

There don't seem to be a ton of PMAC motor controllers out there that can drive a LEAF motor. I found the SEVCON GEN4 inverter which might fit the bill. I'm curious if anyone else has experience with these components.

The LEAF motor initially seemed like a good starting point. It has pretty nice specs and isn't very expensive. I found mine in a local junkyard for around $500.

However, measuring the mounting holes accurately is a hassle. The Nissan engineers didn't seem to align them to any kind of grid, and the geometry makes it hard to measure from a reference point:

I was considering using one of the metal 3d printing services to create a shaft coupler (e.g. sculpteo). I did some test prints with my PLA 3d printer to get the sizing right, but there are a lot of open questions: is it strong enough, and will it be precise enough to be a good fit.

But, to my earlier point about my primary goal being finishing: the DC motor removes a lot of complexity. There are plenty of available controllers, it can run at a lower voltage, which gives me more battery options, it doesn't require a liquid cooling system, it has a simple bolt mounting pattern, and potentially a simpler shaft coupler, etc.

However, I've called all of the junkyards and forklift repair shops locally and haven't been able to find a forklift motor. I haven't found much on eBay that looked like a fit, and that seems like a bit of a crapshoot. It may be easier just to break down and buy new EV conversion components (although it seems like lately, as with many things, a lot of shops have jacked up the prices quite a bit)

Anyway, thoughts or guidance are welcome. I definitely feel like I've entered the "valley of despair" phase of this project.

 

[remy_martian]

The dimensions of the Leaf mounting holes are posted on this site. This is from my collection, posted to save you searching, but credit goes to @Bratitude for originally sharing it (I think he sells these, which would save you a lot of trouble):

I just noticed some dimensions are missing, but they are on this forum somewhere.