[Duncan]

AC v DC
DC is old school - cheap powerful but no re-gen

AC is either
New bits - very very expensive ($20K) - or just expensive and wimpy ($8K)

The best is re-purposed OEM
Which will give you power at a reasonable price

Batteries
Same idea - either New
Or repurposed OEM at a fraction of the price and much higher quality

Tesla don't have a motor at each corner
They have a neat motor/inverter/transmission/diff unit that drives either the rear wheels or the front wheels

Nissan have something similar (but taller) that drives the front wheels in a Leaf

As you have a BMW I suggest you look at Jack Bauer's

http://www.diyelectriccar.com/forums/showthread.php/tesla-powered-bmw-e31-8-series-188202.html

I would go for the Camaro - I like the looks of those and I really like open cars

 

[brian_]

- AC or DC Motor setup in a direct drive manner with a simple forward and reverse switch (and parts above)?

By "direct drive" I assume that you mean directly (without a gear reduction step, but presumably with a shaft) to the car's existing final drive unit (differential). That means the motor will be turning relatively slowly and its output torque will be multiplied only the final drive ratio, which determines which motors will provide enough drive torque to the wheels and which will provide enough power at the low speed.

- Tesla Drive train ?? : Direct drive with no tranny, and motors at the wheels, and a plethora of battery packs - this one is a bit of a mystery to me.

Do you really mean this? It's not how a Telsa works.

In any current production Tesla (and most other current production EVs), there is one motor per axle (not one per wheel). A transmission (one per motor) is used, but it has only a single reduction ratio (a "one-speed" transmission). The transmission output drives a conventional differential. The transmission and differential are combined into a simple transaxle; since the motor is transversely mounted this looks just like a single-speed version of any manual transaxle for any transverse-engine car.

When you see a photo of a Tesla "motor", it is almost always of the complete combination of motor, transaxle, and inverter that Duncan mentioned... commonly called a "drive unit".

No matter how many motors you have - just one, one for each of two axles like a Tesla "Dual Motor" AWD, or one for each wheel - there is one controller/inverter (assuming AC motors) for each motor.

No matter how many controllers are being fed power, you only need one battery (a battery being some combination of cells, usually grouped in modules) for all of them... certainly not a plethora of them. For an example, The Tesla Model S is available with just rear wheel drive (one motor) or with all wheel drive (dual motors), and the battery is the same either way.

 

[brian_]

They have a neat motor/inverter/transmission/diff unit that drives either the rear wheels or the front wheels

Nissan have something similar (but taller) that drives the front wheels in a Leaf

Most production EVs are like the Leaf, and stack the inverter (and charger) on top of the motor because it sits where the gas-engine version has a tall engine. Production EVs with rear motors (including Tesla, but also Mitsubishi i-MiEV, Smart, BMW i3)) typically put the inverter beside the motor to keep it under the floor. All of them put the motor as low as practical (at about axle height), and either

• immediately ahead of the axle (such as the Leaf, Smart EV, Golf EV, i-MiEV), or
• immediately behind the axle (such as Teslas), or
• right on the axle line, with a hollow motor shaft to pass one side's axle through (such as the Chevrolet Spark EV and Bolt, Ford Focus Electric)

It's mostly the placement of the electronics which makes the packaging look different.

 

[omnipotentkuma]

Most production EVs are like the Leaf, and stack the inverter (and charger) on top of the motor because it sits where the gas-engine version has a tall engine. Production EVs with rear motors (including Tesla, but also Mitsubishi i-MiEV, Smart, BMW i3)) typically put the inverter beside the motor to keep it under the floor. All of them put the motor as low as practical (at about axle height), and either

• immediately ahead of the axle (such as the Leaf, Smart EV, Golf EV, i-MiEV), or
• immediately behind the axle (such as Teslas), or
• right on the axle line, with a hollow motor shaft to pass one side's axle through (such as the Chevrolet Spark EV and Bolt, Ford Focus Electric)

It's mostly the placement of the electronics which makes the packaging look different.

Thank you for that explanation. As I'm expecting a rwd vehicle, and hoping for performance, would it be best to lean toward getting a used Tesla drivetrain? I can't imagine the BMW or the Mitsubishi offer much along the lines of performance?



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[brian_]

As I'm expecting a rwd vehicle, and hoping for performance, would it be best to lean toward getting a used Tesla drivetrain? I can't imagine the BMW or the Mitsubishi offer much along the lines of performance?

The BMW i3 is not a small car, and its rated motor power is good for an EV - 125 kW (170 hp); however, it's also not targeted for a high-performance market, so there has probably been little work on pushing its power output.

The i-MiEV is definitely on the low-performance end of the mainstream production EV scale, with a motor rated at 47 kW (63 hp). I haven't heard of any interest in modifications for higher performance with i-MiEV components. The Smart ForTwo ED would be similar.

Much of the "hot rodding" effort in EVs recently appears to have been with Tesla components, so that is the obvious way to go for high performance.

Keep in mind that Tesla power ratings appear to be based on peak - not continuous - output. That means that stock Tesla motors, batteries, and electronics can withstand those high power levels at least briefly, while peak performance of those components in other vehicles are largely unknown because their stock control systems do not allow operation at higher than their rated power (even if they are physically capable of handling it).

To illustrate this, while the Leaf is rated at a modest 80 kW, the same motor is now (starting with the 2018 model year) rated at 110 kw (147 hp), due to changes only in inverter cooling and control logic. Some people have pushed the Leaf motor much harder - I couldn't find a link in a quick search, but perhaps someone else can post an example.

 

[omnipotentkuma]

AC v DC
DC is old school - cheap powerful but no re-gen

AC is either
New bits - very very expensive ($20K) - or just expensive and wimpy ($8K)

Duncan, you mention the expense with new parts, and part of my initial thought process was to get one of these Warp 9 Motors and try to mate it to my existing transmission and rear end. ( I see people doing this in YouTube videos) wouldn't this be cheaper then trying to get a Tesla Drive, and corresponding batteries? Your thoughts?

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[Duncan]

Hi Omni

The Warp 9 motor (or warp11) are just tarted up forklift motors

I'm using an 11 inch motor - direct drive to the diff in my "Device" - cost me $100

I have been abusing mine for the last five years - but I did manage to blow it up at our Drags on the 4th March
I was using 1200 amps and 340 volts
Wee bit more than the 200 amps and 48 volts it was in the forklift

As I said cheap and powerful - but not real sophisticated