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Discussion Starter · #1 ·
Hi, new to the forum. I want to convert a 1976 Fiat Spider 124 to an electric vehicle. Looking for a motor and would like suggestions. I am thinking of some kind of 48 V series wound DC motor with about 100 ft lbs torque and about 15 HP. Forklift motor maybe? I will drive through the 5 speed transmission that is in the car now. Probably LiFe batteries running 48 V. Also looking to see what kind of instrumentation is available. Some plug and play display for current, voltage and battery capacity. Will also want to monitor temperature.
I have not searched the forum yet so all the answers may be there. Just wanted to get the ball rolling. Probably start a thread on my project. I am in Windsor Colorado.

Thanks
Automotive parking light Car Wheel Tire Vehicle
 

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Why would you run a big chunk of iron in a pipsqueak car like that when you can get a motor that's half the weight to produce around 15kW?

Weight is everything in a small sportscar, and every pound you add in junkyard garbage is a pound of battery you can't carry.
 

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Discussion Starter · #3 ·
Why would you run a big chunk of iron in a pipsqueak car like that when you can get a motor that's half the weight to produce around 15kW?

Weight is everything in a small sportscar, and every pound you add in junkyard garbage is a pound of battery you can't carry.
What would you recommend? I would like to beadle to do highway speed once in a while if necessary. My understanding is that HP is necessary for highway speed. Based on a drag coefficient of .45 I would require a force of 65 lbs at the wheel to sustain 65 mph. If I did the math right hat is about 15 HP at 3000 rpm. Are you suggesting run a smaller motor at higher voltage with an air blower? I agree, keep weight down, but I do not want lack of top end performance. What do you think?
 

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Nobody will be your personal librarian, anywhere.

I, and others here or elsewhere bill our time at several hundred dollars an hour and volunteer info in our spare time for future readers' benefit - you want me to waste my time Googling a motor model number I spoon fed you?

Sorry. No. Either man up and do your own lifting in your project (everybody here will HELP for the future benefit of many, but nobody will hold your hand), or show you're a delicate snowflake that exploits others' time and leave after you cannot.

When you're done fetching, you share your findings for others.
 

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Discussion Starter · #11 ·
Thanks Floyd. I am considering the AC-34 Induction kit by Electricmotorsport.com as a possible solution. Waiting for them to get back to me. There are lots of dealers on the web that may do the job along with DIY approaches. And, I can see that there is a lot of good info on this forum. Did not know some people charged for their input to a forum. Never ran into that before in many of the other forums I am on. Thanks again Floyd.
 

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I am new at this. "ME1302" means nothing to me. I will try searching the forum for a reference.
Just that motor model name wouldn't mean much to anyone not already familiar with this area of interest, but a quick web search should find the Motenergy ME 1302 motor quickly; I understand the frustration if it does not, but the manufacturer's name (Motenergy) should help.

Some technical discussion would be appreciated.
Enough power to acceptably drive a car (even a compact car like the 124 Sport Spyder) would require huge currents at only 48 volts. The lowest-powered variant of that car had a 66 kW engine; 66 kW at 48 volts would require 1375 amps (if the motor were perfectly efficient)... over three times what a typical modern compact production EV handles at maximum power, because those production EVs run 7.5 times higher battery voltage (and have more than twice that power).

Note: power = voltage X current
 

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Did not know some people charged for their input to a forum
They don't, remy was saying that he would have to charge $$$$ if this was his job. You will find that remy is knowledgeable and sometimes an ass, why he didn't just say google it I don't know. it took more energy to type LMGTFY than it did to copynpaste the two links (I have the sites bookmarked).
later floyd
 

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Discussion Starter · #14 ·
I have heard that you do not need all the horse power of an ICE. With the high stall torque of an electric motor there will be no problem starting out even in 2nd. However, running at 65 MPH requires horse power but no where near 66 KW. The horse power required is only necessary to overcome friction and wind drag. That is about 15 HP or 11.2 KW or 233 amps at 48 volts. I would run at 72 volts and us a blower to cool the motor only requiring 155 amps. Now climbing a hill is a different story. Doing a trade now to see if I should go with DC Shunt, Brush Less or AC Induction and if I should go DIY or buy a kit. Good technical interchange between members makes a forum of value to all.
 

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Discussion Starter · #15 ·
Understanding the difference between torque and HP, where they play in the operation of a vehicle and the deference between Electric Motor and ICE torque curves is necessary to build a good EV retrofit design. I appreciate the inputs.
 

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I have heard that you do not need all the horse power of an ICE. With the high stall torque of an electric motor there will be no problem starting out even in 2nd. However, running at 65 MPH requires horse power but no where near 66 KW. The horse power required is only necessary to overcome friction and wind drag. That is about 15 HP or 11.2 KW or 233 amps at 48 volts. I would run at 72 volts and us a blower to cool the motor only requiring 155 amps. Now climbing a hill is a different story. Doing a trade now to see if I should go with DC Shunt, Brush Less or AC Induction and if I should go DIY or buy a kit. Good technical interchange between members makes a forum of value to all.
Good catch to consider grade climbing, but you forgot about acceleration... which is very important. That's the biggest reason that real cars don't have just 15 horsepower.

I'll also note that no current production EV can drive at 65 MPH on 11.2 kW (which would be only 172 Wh/mile or 107 Wh/km).

Also, why a brushed DC shunt motor? Do you have one of the obscure controllers for those lying around your garage?
 

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Don't reinvent the wheel here. A very popular and easy route to go is a Leaf swap. It'll be 1000x more driveable than your forklift motor, the entire thing weighs less, and with 80kw+ at your disposal in that sized car, you'll be limited by the tires, drivetrain and brakes long before you'll be limited by your motor. Not to mention it's much cheaper over all when the batteries, motor, inverter, charger, etc. all come as a package deal.

(Also, you get an pretty good boost in drivetrain efficiency, and it doesn't make hideous brushed DC motor noises)

Also think about:
1) what fabrication ability/capability do you have at your disposal? You want to keep the 5 speed so that's involving an adapter plate and a coupler. Plenty of options to go about that, but they're very precise parts you need to create, especially when it comes to shaft alignment.

2) Its a fiat 124, that's a tiny car. Where are the batteries going to go? That will also dictate the type of cells you can fit in the car. Thankfully Leaf packs break into pretty small modules so you can play Tetris with them.
 

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Discussion Starter · #18 ·
All good thing to consider. I need to do a lot more research, here and on the web, before I come to a final decision. Right now I am getting the 124 stripped and ready. There have been several conversions of Fiat 124s in the past. Peter Gabrielsson's 1977 Fiat 124 Spider as an example. I like it as a test bed, it does have plenty of room for batteries and I am only looking at about a 30 mile range.

Large electric motors have plenty of torque at stall (Only need about 100 ft lbs) for initial acceleration. For passing at highway speed (High RPM) not so much. Check out a DC motor torque curve. Also, the 11.2 KW is only during level 65 MPH cruise, not average city and highway usage.

I am in the process at looking at the possibility of a Hydrogen Fuel cell with a High Power storage capacitor. I do not believe that Lithium is the ideal way to go in the future. Hydrogen has a higher power density but presently requires large volume for storage and there is very little infrastructure.

My objective with this project is to have fun building, learn about EVs and utilize my former Lockheed System Enginering and Flight test experience to optimize a inexpensive DIY design that can evolve. I dig instrumentation and expect to put a lot in. As you suggest I will have to look at the Leaf and Prius salvage approach. I will go search the forum.

I think it is time to move this thread out of Introduction and may be to some DIY projects or Motor selections areas? How would you do that?

Thanks Larry
 

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Howdy,
Just start a new thread for your project.

First, thing is to establish your "goals" (top speed, acceleration, range etc.)
...then, do lots & lots of research, before you buy anything.

The more you learn the more your "plan" will evolve
...& also, new products are being developed almost daily ;)
 

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You might also check out the openinverter forum. Lots of technical information on ev components and controls. And look at the open source controllers in the web shop. I second the suggestion to look at the Leaf drive and batteries. Seems to be a good supply at relatively reasonable prices.
 
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