Yes, You CAN Convert an Automatic to Electric

by Brian Monahan
(Ashland, Wisconsin)

I've done it, twice now, and I'm very pleased with the results.

I average about 45 miles on a charge, same as everybody else. My range would be better, but I always seem to have my foot in the battery pack.

Most cars and small trucks today are all automatic, and I was reluctant to convert one of these automatics to electric just like everyone else until I realized that the electric motor could do the same job as the ICE that was in it - all I had to do was put another actuator in place.


The AT is a very simple device that is totally hydraulic in nature, pumping hydraulic fluid through its inner workings to cause pressure against a metallic plate, causing the vehicle to move.

How I got around the electronic shift and the RPM stall was simple too. On most modern automatics, they are electronic shift. It takes a reading on the torque verses the speed of the motor, and shifts according to the conditions.
With the electric motor, you lose that sensor readout; so I took the same TYPE of device (a crank sensor, attached to the bell housing) and placed it on the electronics of the dash plate. The readings for the shift now come from the road speed and the RPM reading off the electronic gauges in the dash plate, instead of the gas engine.

It really isn't a big job to reroute a few wires and buy very affordable electronic pickups for these issues, and it works perfectly.

Like I said, I don't go any farther down the road on my conversions than any other guy has, about 45 miles on a charge, but then again, I am the Red Baron when it comes to driving, and I seem to always have my foot in the battery pack instead of behaving like an adult. But even with me behind the wheel, I feel it handles conditions great.

The point is, people have to TRY stuff to see if it works or not. If we'd never tried making tools - the "expert" apes probably said couldn't be done, either - we'd still be swinging from trees; )

Comments for Yes, You CAN Convert an Automatic to Electric

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78' T Bird
by: A-rod

What a nice read! I am excited to see the diy EV back yard builds are rising up all over the country! :)

I have been thinking of converting an older car to all electric. It has many modifications to undergo to help with weight distribution and weight reduction, but I already own the car amd it has a C4 like one of the post above.

My inquiries are related to that transmission, and how does going from a higher rpm to a lower one effect the motor? I didn't get quite a clear answer from reading. Do I need a custom valvebody? I figure it shifts at really low rpm anyway so this might be fine if I left the torque converter installed? Assuming I keep the cooling apparatus. Is it better to couple the motor to the trans. Without the torque converter? If so how does going from 2500-3000 rpm to 1000-1500 feel on the motor, is the transition rough, does it damage the motor to be slowed so quickly? Is this an operation the controller manages?

Just looking for any help/ direction to keep me reading up on this marvelous topic of converting to clean rechargeable energy.

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automatic ev conversion method
by: Anonymous

I have seen a conversion that used a 5k potentiometer instead of pot for an automatic to electric conversion to change shift points, so that could be an option. Also wouldn't you have to idle the motor to create hydraulic pressure

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Extended range, electric vehicles .
by: Anonymous

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Automatic Without Torque Converter
by: Sri Welaratna

With the motor driving the automatic transmission without the torque converter how do you avoid a jerking motion when there is a gear change during motion, say from first to second? Isn't the torque converter essential to the smooth transition from one gear to the next? Or do you coordinate the gear change with the motor controller to take up the torque conversion within the motor?

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EV with automatic transmission
by: maurice

Hi Brian,
I am glad you were able to figure this out about the automatic transmission that is electronically shifted.
Will this work for all electric shift transmissions ???
I have a 97 chevy suburban 1500 and its transmission is a later version of the turbo-700-R4, which became the 4L60E if I am not mistaken.
Your reference to a " Dash Plate " I do not want to seem stupid, but what is a Dash Plate???
I can find no reference to it at all... LOL
Please explain.
Thanks

Maurice

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Question
by: Anonymous

Would I be able to do a EV conversion with a 2002 Dodge Intrepid 2.7 automatic? If so, what would estimated costs be for a bsic setup? Plz help, Thx!

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Torque Converter
by: Anonymous

Dear Brian

Great to hear you are not afraid to do something not many has done.

My question is, how did you couple the motor to the trans?

I am planning to use clutchless type of coupler to where the torque converter once was. This should reduce the jerkiness of the initial torque and be able to reduce the wasted energy graetly.

Let me know what you or any other guys have done.
here is a link to my conversion thread:
http://www.diyelectriccar.com/forums/showthread.php/jaguar-xk8-96-ev-93252.html

feel free to leave any comment!

Rui

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specific questions regarding auto ev conversion
by: Anonymous

We have an auto Neon, looking to do ev conversion. What exactly did you use to connect the electric motor to the trans input shaft?

What exactly did you connect the crank sensor to? or place it next to for it to sense a and produce an output?

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I'd like to know
by: Anonymous

Good to know you can actually convert an automatic car.

I live in Mexico city where recently there has been severe traffic regulations related to the use of "old" cars. Considering that ironically the gas price in Mexico is higher than ever,I decided to electric convert my hansome old faithful BMW Z3 1.9 roadster. But, what a bummer, has automatic transmission.

Selling the car is NOT an option and changing the whole transmission really is out of my budget.
As mentioned by Tim (previous poster), I'd would like to know those specific roundabouts to convert the car.
A crank sensor sounds good, but I'd like not to interfere with the car's computer as I plan to get rid off it (and get advantage of the brand-new electric car control panel).

I agree that SOMEONE should have done it before somewhere, but a little help would be really appreciated.

Cheers! ยกGracias!

Alberto

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Convert 1996 Acura 3.2 TL to electric
by: Anonymous

How about a VERY efficient Automatic in a 1996 Acura 3.2 TL? It gets almost 22 city/28 hiway MPG with a v-6

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maybe you can help me?
by: Sal

I have an old electric ford ranger with an automatic transmission and it doesn't run. The control card was bad, but I had it repaired. When I turn the ignition on, nothing happens. The question is: how does the auto transmission work? should the motor start spinning when I turn the ignition on? or should it start when I put in drive? or when I press the gas pedal?

Hi, Sal -
I emailed a fellow Ford Ranger EV owner, told him your situation, and he said:

"...An electric vehicle doesn't have an idle mode. When you stop the motor stops spinning. And typically when you turn it on there's no motor noise. Sometimes a fan turns on, but otherwise there is no noise. Just push the accelerator peddle and off you go. Unless the controller isn't engaged or powered, in which case there is an electrical issue that needs to be resolved."
Hope this helps!

- Lynne

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convert an auto tran to ev
by: brad

i plan on converting a 86 volks cabrio with an auto trans . any comments on probs i may encounter and what can i expect in approx cost. it need to be a freeway driver capable of approx 80 mile round trips

Hi, Brad -

At 80 miles on a charge, you're already at the top end of homegrown EV range. With an AT, you can expect to reduce that range further. Cost depends on what you're willing to do yourself vs. buying new and premade.

- Lynne


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Cooling AT Fluid
by: Anonymous

The torque converter in an AT is typically what generates the most heat since you've got two "clutches" spinning in a sea of trans oil, generating lots of heat. The oil in the clutch packs in the trans don't really make as much heat as the torque converter but it does produce some heat. One way I did it was to put a performance aluminum oil pan with cooling fins and a higher oil capacity on the C4 so there's more oil to absorb the heat that is generated. Also, since the elec motor doesnt throw as much force on the trans as a performance V8 going down the drag strip, its not really chewing up the guts that hard. Now in the instance of doing a conversion on a compact car that when converted will weigh more than its ICE version due to batteries, you can easily get an aftermarket trans cooler and mount it in the grille and run the tubes over to the trans to serve as a means of cooling the oil. A fan wouldn't be needed since the air moving through it when the trans is spinning and hence moving the car along.

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Questions about automatic conversion
by: Alex K

Brian, how can I get in contact with you to get advice on modifying an automatic transmission for an ev? Thanks. My email is AL75k at yahoo dot com.

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Transmission fluid question
by: Anonymous

I was wondering how you would keep the transmission fluid cool, since the radiator is usually removed, and the fluid typically goes through the radiator for cooling. So, do you leave the radiator installed for cooling, or is there some other way? Can you explain how you do all that?


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Another auto trans conversion
by: Anonymous

Another way to do a conversion using an auto trans is to do the car in direct drive. This of course involves using a coupling that would go between the motor shaft and the transmission shaft. You pull the torque converter and the inner shaft is what gets coupled to the motor. Since the motor won't be turning all the time, this can (and has been) done. Everything else applies as far as altering the trans to trick it into shifting when you want it to as well as having an extra pump on the oil line. From the conversion I did on an old mustang, the lag time between when the motor started up and the transmission started grabbing was very small. Without a radiator in the oil system (no torque converter to get hot),it doesn't take long for the oil to move through the transmission. A high cap oil pan with cooling fins makes for sufficient cooling within the transmission. As far as shifing in the mustang, since the transmission is a C4, aftermarket reverse manual valve bodies are available, allowing me to manually shift the transmission. This allows me to start off in any gear I want, without the worry of fancy apparatus to electronically control the transmission. Simplicity and convenience at its finest.

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Reply to: Yes, You CAN Convert an Automatic to Electric
by: Tim Beasley

Thank-you Brian for your excellent article.

Quoting your closing statement:
"The point is, people have to TRY stuff to see if it works or not. If we'd never tried making tools - the "expert" apes probably said couldn't be done, either - we'd still be swinging from trees"
this is completely true, people need to try different ideas and methods because this is how we make improvements, and all the improvements put together make a better vehicle.

I believe if you are going to convert a vehicle with the intent to give others the opportunity to own it(which is my intent), you need to make the vehicle as convenient, and easy to maintain and operate as possible.

The cost of the conversion components, the donor vehicle and your time, dictate the need to ask many dollars for a converted vehicle ($18,000 ??). It could be challenging to sell a vehicle which will only travel 50 miles on a charge, so the vehicle must be built from an excellent donor and be easy to operate and fully functional.
An automatic transmission would make operating the vehicle much easier for an owner who may not want to "operate" a vehicle as much as just get in and drive.
Brian, I would like to learn more details of how you control your automatic. How you deal with transmission oil circulation at a stop light (auxillary pump?) How you control your shift points. I'd like to hear how you determine your range (I guess that applies to anyone's vehicle) How did you find the data on your transmission and the mechanics of making it shift when an how you want. And finally how much time you spent on the conversion.
Thanks again for the great article.
Tim

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