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Discussion Starter · #1 ·
Greetings -

I am located in Central Pennsylvania and have lately been drawn to EV conversions and EVs due to moving farther from work (yea, dumb - I know!) and by the recent re-evaluation by the EPA on CARB requirements regarding aftermarket performance parts and legality on our streets.

If the law changes the game regarding ICEs - change power plants!

With the cost of EV conversions still being relatively (everything is relative) affordable and the EV conversion knowledge base expanding I thought this may be a good place to start and bounce Ideas off of people's knowledge filled minds.

I have two projects in mind.

The first is a mini truck converted to give me the ability to charge to get to work (35 miles). Hilly terrain - about 60 % highway.
I have a lead foot - so I'd like to the truck to easily go about 80 mph for about 20 sustained miles. And to do burnouts - because a smoking tire is a happy tire.
There are chargers at work - so I can charge to get home.

The second is a fabricated chassis autocross or rallycross car. Other than the Idea of being able to build a car and race it and be able to change out battery packs between runs - I haven't much thought about how to get this done.

I do have a question - on a converted car with a manual trans - why does it seem that only a couple of gears are used? Isn't changing the rotating speed of the motor always the goal to reduce "fuel" usage?

Also - other than possibly not having reverse - is there a reason why more conversions don't involve an independent rear with a motor directly attached to the diff? It seems much simpler to do and just weld (bolt?) the assembly to the hole you cut in the car you are converting. Just a question. I guess I was thinking about this for the race car project.

It's pretty cool to have a forum to go to. I am thankful.

Seeker 589
 

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Welcome! :)

The second is a fabricated chassis autocross or rallycross car. Other than the Idea of being able to build a car and race it and be able to change out battery packs between runs - I haven't much thought about how to get this done.
You should be interested in this project:
Toyota 4Runner 4x4 Race truck Leaf conversion

I do have a question - on a converted car with a manual trans - why does it seem that only a couple of gears are used? Isn't changing the rotating speed of the motor always the goal to reduce "fuel" usage?
The output and efficiency of electric motors can be less sensitive to speed than an engine, so less optimal shifting is required - details depend heavily on various design and configuration choices of the motor, controller, and battery. The top ratios of typical transmissions are useless for typical motors (motor speed would be too low), and first gear typically isn't needed, so not many gears are left to use.

In addition, a clutch is not needed to avoid stalling, so conversions often connect the motor to transmission without a clutch; however, with no rev-matching feature in the motor's controller, the massive rotational inertia of the motor can make these difficult to shift (especially downshift) so drivers avoid shifting.

Also - other than possibly not having reverse - is there a reason why more conversions don't involve an independent rear with a motor directly attached to the diff?
The ring and pinion gearing of the final drive (diff) by itself isn't enough reduction ratio to be suitable to get the most out of most motors. Production EVs typically have an overall motor to wheel speed ratio of 7:1 to 10:1, and diff ratios are typically 3:1 to 4:1. This approach has been taken: I've seen in both in a racing vehicles that needed the tall gearing for high speed anyway, and in an RX-8 in this forum with a relatively low-speed motor.
 

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With the cost of EV conversions still being relatively (everything is relative) affordable and the EV conversion knowledge base expanding I thought this may be a good place to start and bounce Ideas off of people's knowledge filled minds.
Just a warning, its pretty hard to do an EV conversion for less than the cost of something like an engine swap, unless you're willing to essentially build a lot of the components yourself (inverter, charger, dc/dc).

How much are you willing to spend on a conversion?
 

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Discussion Starter · #4 ·
How much are you willing to spend on a conversion?
I was thinking $1500 - $3000 for a conversion on a mini-truck in relatively decent condition using some used or scrounged components.

I weld and can fab most things steel - so I can do custom brackets and racks.

My biggest challenge will be couplers and adaptor plates.

Calculating motor size, battery size, range and available sustainable speed will be a challenge until I understand the math and machine properties.

I'm also not in a great hurry. Collecting parts can be done over some time.

Thanks for your reply.
 
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