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Discussion Starter #1 (Edited)
Hello All,


I am planning to build an electric classic mini pickup.

  • My skill level with auto mechanics, fabrication, and electrical are always in learning stage
  • The range I am hoping to get is 150 Km/charge (about 100 miles/charge)
  • I am hoping to get fun and fast level of performance, perhaps some race or drifting on the weekend
  • Some parts that have been considered:

  • AC-50 Motor-96 Volt
  • Curtis 1238e-7621
  • 5 Tesla Model S Battery Module @5.3kWh
I am planning to built it as a rear-wheel-drive mini pickup, pairing the AC-50 direct to the input of a Mazda RX-8 rear diff (or Honda's B series trans -- which should I use?) putting them together into a new rear sub frame.
I read in the other thread, by Brian (?) I should not pair a motor directly to a differential?


Another alternative is using Tesla rear small drive, but would cost a lot more =D

hope there any inputs?
Thank you
 

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I am planning to built it as a rear-wheel-drive mini pickup, pairing the AC-50 direct to the input of a Mazda RX-8 rear diff (or Honda's B series trans -- which should I use?) putting them together into a new rear sub frame.
I read in the other thread, by Brian (?) I should not pair a motor directly to a differential?
The only issue is gearing. The speed reduction ratio from motor to axles is all from the ring-and-pinion gear set of the final drive ("differential"), and unless you have a low-speed motor or an extreme ring and pinion set, that won't be enough. If you know what speed you want the motor to turn for a given road speed, and the tire overall diameter, you know what you need for gearing.

The point of a transmission would be to allow you to shift to suit the gearing to the speed which you are driving. Multi-speed transmissions are generally not used in production EVs because the same (and sufficient) motor power is available over a broad range of speeds; that is not true of low-voltage configurations with the motors typically used by DIY builders.

Production EV motors are designed to turn much faster than old brushed DC motors; the AC-50 may be somewhere in between, but the best speed depends on voltage (and you will have only about 96 volts). It can turn at least 8,000 rpm, but its output peaks much lower and is very low by such high speeds with only 96 volts; perhaps the gearing would work well with just the ring and pinion gears.

This is a project which mounted a motor directly to an RX-8 final drive:
Latvian mazda RX-8 project

The published peak output of an AC-50 supplied with 96 volts is only 71 hp, and that is only at one ideal speed and drops off rapidly with increased or reduced speed. Unless the surface is very slippery, I can't see drifting with that... even with a transmission to keep the motor close to its peak output.
 

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Discussion Starter #3
Thank you Brian.

What is your recommendation for me to make a 'fun' rear wheel drive mini?



Would the small rear drive tesla motor be better? since it has the diff attached.. would the 25KWh of batt be enough?
 

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What is your recommendation for me to make a 'fun' rear wheel drive mini?

Would the small rear drive tesla motor be better? since it has the diff attached..
Any of the production EV drive units incorporates the motor, reduction gearing, and differential. The most commonly used are the Tesla (small and large) Model S/X units, and the Nissan Leaf, but a recent project here used a Chevrolet Bolt drive unit (Westfalia T3 with Chevy Bolt drivetrain).

For mounting at the rear of the truck, the drive unit needs to be low to fit under the floor. That means any of the drive units which are found in that location in the stock EV will likely work (Tesla, Mitsubishi i-MiEV, BMW i3); the front drive units which normally have the inverter and other components stacked on top can likely be used by relocating those components (that Westfalia is an example).

To get enough power for effective drifting, if using a production EV motor either you need one with high enough output in stock form (such as the Teslas, or the Bolt at 150 kw), or a way to override the power limits of the inverter hardware or controller programming - most Leaf motors are only rated 80 kW but can handle much higher power.

If not using a production EV drive unit, there are many motor choices... dependent on your budget. I would just look for more power than the AC-50, at the motor speeds that you will be driving.

would the 25KWh of batt be enough?
The energy capacity of battery is important primarily to range. The other consideration is maximum sustainable power output, although any EV battery with enough energy capacity will likely be able to handle enough power for this purpose.
 

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Discussion Starter #5
Any of the production EV drive units incorporates the motor, reduction gearing, and differential. The most commonly used are the Tesla (small and large) Model S/X units, and the Nissan Leaf, but a recent project here used a Chevrolet Bolt drive unit (Westfalia T3 with Chevy Bolt drivetrain).

For mounting at the rear of the truck, the drive unit needs to be low to fit under the floor. That means any of the drive units which are found in that location in the stock EV will likely work (Tesla, Mitsubishi i-MiEV, BMW i3); the front drive units which normally have the inverter and other components stacked on top can likely be used by relocating those components (that Westfalia is an example).

To get enough power for effective drifting, if using a production EV motor either you need one with high enough output in stock form (such as the Teslas, or the Bolt at 150 kw), or a way to override the power limits of the inverter hardware or controller programming - most Leaf motors are only rated 80 kW but can handle much higher power.

If not using a production EV drive unit, there are many motor choices... dependent on your budget. I would just look for more power than the AC-50, at the motor speeds that you will be driving.

The energy capacity of battery is important primarily to range. The other consideration is maximum sustainable power output, although any EV battery with enough energy capacity will likely be able to handle enough power for this purpose.

Since I still have steep learning curve ahead, and you're suggesting that the AC-50 would not so much fun :D, I think I should just buy a kit and try the Tesla's SDU and build new rear subframe for the mini pickup.

For battery I will start with 5 or 10 of tesla's 5,3 kwh modules make them work for 114V or 228V. What do you think?



EVshop eu seems to have the lowest price compare to HSR, Stealth, Zero ev, and EV west. Do you have experience with any of them?


May be next time I have the luxury to be able to learn and build something that the openinverter is offering.
 

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Since I still have steep learning curve ahead, and you're suggesting that the AC-50 would not so much fun :D, I think I should just buy a kit and try the Tesla's SDU and build new rear subframe for the mini pickup.
That makes sense to me.

For battery I will start with 5 or 10 of tesla's 5,3 kwh modules make them work for 114V or 228V. What do you think?.
It might be okay with 228 V, but at 114 volts performance would be poor.

EVshop eu seems to have the lowest price compare to HSR, Stealth, Zero ev, and EV west. Do you have experience with any of them?
I have no experience with them, but others in the forum have worked with at least most of them... and at least one member works for one of them.
 

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Discussion Starter #8
That makes sense to me.


It might be okay with 228 V, but at 114 volts performance would be poor.


I have no experience with them, but others in the forum have worked with at least most of them... and at least one member works for one of them.



is the member is Kevin for Zero EV?
(I send them message, but no reply yet)



I have just finish reading about Kevin's split screen vw..
https://www.diyelectriccar.com/forums/showthread.php/1967-vw-split-screen-van-ice-177489p28.html


very inspiring..
want to follow the same route..


just to make sure.. I can just change the logic board in Tesla SDU to programmed all the parameters?



https://www.evbmw.com/index.php/evb...small-drive-unit-logic-board-built-and-tested
 
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