# The ?Automatic? Solution for EV Conversions



## FB Performance Trans (Dec 14, 2010)

Some time ago we were approached by a City Municipality that was in the process of doing a fleet conversion of their gas vehicles to electric. Their bottom line was to achieve vehicle performance and functionality that replicated that of the gas vehicle while of course providing long term energy cost savings. Their approach was to follow the lead of so many others by setting up the driveline with a “stick” type transmission. 

Their first prototype proved to be very successful in all areas except one: Drivability. This unfortunate outcome was due to the use of a high torque electric motor in combination with repeated clutch engagements necessary during the normal gear changes. Numerous attempts to feather the clutch to prevent the sudden jerking of the vehicle and its passengers proved to be unacceptable. 

They realized that the only solution would be to replace the stick with an automatic type transmission. On the surface this sounded easy enough, except that they discovered that throughout the EV industry most were skeptical about using an automatic for this type of application. So after much resistance to this idea, they decided to go outside normal channels and they contacted us. The result has been their complete satisfaction in achieving their “bottom line”. 

Our objective here is to make everyone aware that the automatic transmission is absolutely a viable alternative. Let me start off by briefly acquainting you with our company. FB Performance Transmissions is a family owned and operated business. We’ve been successfully producing high performance and racing transmissions for a variety of automotive aftermarket applications since 1988. One of our specialties over the years has been the ability to adapt various transmissions to different types of motors. More recently of course we’ve been applying similar technology for Electric Vehicle purposes. 

We’ve developed these transmissions and engineered the related equipment specifically for use in these types of applications. We now offer two 3-speed automatic transmissions. Both of these units are based on the original Ford AOD and AODE transmissions. We chose these transmissions because of the availability of a Low Gear Planetary set and the fact that we can custom build them to handle 1000+HP if necessary. 

The AODE is fully automatic with a programmable Power-train Control Module (PCM) where all of the shift points can be varied and set as desired. The AO3 uses a Full-manual valve body where the driver always has total control over the transmission functions. The valve-bodies in both of these units are designed to eliminate the normal fluid bleed off, so that the transmission can react immediately to the input torque of the electric motor. They both have the strength and durability to handle the typical torque of these motors in conjunction with the weight of vehicles. Yet they provide a smooth transition when shifting from one gear to next, without the sudden jerking response typically found when using a clutch with stick type transmission. 

We have also successfully engineered and fabricated the entire mounting interface between the Electric motor and the transmission. These components include the following and are listed as options on our spec sheets (See Links Below):
1) Motor to Transmission Billet Mounting plate – easily adaptable to a variety of electric motors that incorporate a surface mounting plate.
2) Motor shaft Rigid Steel Coupling – designed to fit a number of different motor shaft diameters and torque requirements.
3) Steel Flexplate – permits direct mounting of the Torque Converter (Fluid Coupler).
4) Torque Converter/Fluid Coupler – engineered for minimum stall and maximum coupling efficiency and fluid dampening.

The completed package of components provides for a very rigid assembly and permits a very simple installation into almost any type of rear-wheel drive vehicle. To better illustrate this I’m enclosing a series of assembly photos. (See Attachments below). The following links cover both of these transmissions:
*Heavy Duty AODE (4R70W) Non Lock-up- Electric Motor Conversions*
http://www.fbperformance.com/viewtrans.asp?TransmissionID=100

*Heavy Duty AO3 (AOD) Non Lock-up - Electric Motor Conversions*
http://www.fbperformance.com/viewtrans.asp?TransmissionID=101 

If you have an interest or any questions about what we’ve developed, please contact us and we be glad to go over all of the details with you.

Contact: Mike or Fred
In NY: 1-631-242-0008
Outside NY: 1-800-769-1118
FAX: 1-631-243-3054
E-Mail: [email protected]
Web: http://www.fbperformance.com


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## Renny_D (Apr 21, 2009)

How are you dealing with the need for the motor to "idle"? Do you run an external pump or are you relying on the controller to be modified to provide the idling rpm for the pump. Would be neat if you solved it without the controller having to idle the motor. Also are you using a very low stall speed on the tranny? Standard stall would be a waste of energy as the torque multiplier isn't really needed.



Thanks
Renny


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## FB Performance Trans (Dec 14, 2010)

Hi Renny
No. From what we gathered when we first got involved in the EV market place was that many felt that the automatic was not suitable for these applications because the electric motors are normally not idled. When they&#8217;re turned off there&#8217;s a tendency for a certain amount of fluid bleed off in the transmission. As I mentioned in my opening comment regarding the (2) transmissions, we have been able to significantly reduce the bleed off: 

_The valve-bodies in both of these units are designed to eliminate the normal fluid bleed off, so that the transmission can react immediately to the input torque of the electric motor. _

The fluid restriction and internal pressure readings were initially tested by simulating the &#8220;on and off&#8221; operation of the transmission on our Dyno. It was later confirmed in the actual operation of the EV vehicle itself. In fact, one the converted vehicles was a full size van weighing over 6,000 lbs. Even with all of this weight and the high low-end torque of the motor, the transmission and converter provided a very normal take-off after each stop.


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## Alchemist (Apr 16, 2009)

Happy New Year Mike, Fred!

This is exciting news! I only wish I lived closer to your shop to see and experience your application. Hope you guys get involved with other electric car needs! Thanks for sharing. 

Can you fab an adapter plate for an AC motor?

May the New Year bring you much success and property.

Ernie


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## FB Performance Trans (Dec 14, 2010)

Hi Ernie
Thanks! We certainly share your passion for using automatics for EV conversions. In fact, every motor manufacturer that we’ve been in touch with has also been very enthusiastic about it. 

The Adapter plate that we designed can be used with any electric motor as long as the motor has a face plate with mounting holes. Motor shaft diameter is not an issue either because the Taper lock bushing can be sized to fit the both the shaft diameter and the Steel Rigid Coupler. We intentionally designed all of the adapting components to be as accommodating as possible for different applications.

Happy New Year!


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## ElectriCar (Jun 15, 2008)

Thanks, I'm considering an auto for the wife. She has a Civic, 2001. Any ideas on that?


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## Alchemist (Apr 16, 2009)

Mike/Fred,

Some shops will build a part "just enough to make it work" but couldn't care less about it, so I'm relieved to hear that you share the passion for EV conversions. 

May I ask you, what does the trans weight dry/weight please?

Is there any possibility of you guys getting more involved with EV conversions along with the automatic conversion - like motor swaps/kits?

Thanks for your time - I'm excited for you guys!

with respect,

Ernie


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## FB Performance Trans (Dec 14, 2010)

> Thanks, I'm considering an auto for the wife. She has a Civic, 2001. Any ideas on that?


I wish we could help you with that but we rarely get involved with front-wheel drive vehicles of any type. All of our transmissions are built for rear-wheel drive and 4x4 applications. I would recommend looking for those who have successfully done front-wheel EV conversions.


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## FB Performance Trans (Dec 14, 2010)

> Some shops will build a part "just enough to make it work" but couldn't care less about it, so I'm relieved to hear that you share the passion for EV conversions.





> May I ask you, what does the trans weight dry/weight please?
> 
> Is there any possibility of you guys getting more involved with EV conversions along with the automatic conversion - like motor swaps/kits?
> 
> ...


That seems to be the way it is sometimes. Fortunately we had an opportunity to develop not only the (2) transmissions for the EV conversion, but all of the adapting components as well. When we were informed that these transmissions would be used in a variety of vehicles, it became even more important to make these components as universally adaptable as possible. 

Obviously there’s also a big difference when you’re fabricating something like this for yourself versus being contracted to do it for someone else. An individual inclined to do this on their own can more or less tolerate his own mistakes and the time (and money) involved to get it done right. However, a customer will not share similar tolerance if they’re paying for an engineered product if it doesn’t work properly. Most in business realize that you won’t often get a second order if your original equipment doesn’t perform as quoted. We also believe that there’s an intrinsic value in achieving a solid reputation for providing quality equipment. It’s something that we hold in high regard.

Both of these automatic transmissions weigh about the same as they did when they were first introduced into the automotive market: 135 lbs. The torque converter weighs 28 lbs. 

At this point we feel comfortable just supplying the transmissions and related adapting components. There already seems to be an enormous amount of expertise and capabilities when it comes to actually doing an EV conversion. Our hope is to make more people aware of their options when it comes to selecting a transmission for their planned EV.


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## Alchemist (Apr 16, 2009)

Hi Mike, Fred, (whomever is responding to my comments please - LOL!)

Thank you for taking the time to provide the info I inquired about. I really appreciate people/shops like yourselves, who step up with quality parts and stand behind them. Thank you for your time!

Ernie


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## Bowser330 (Jun 15, 2008)

Thank you for providing your products to the EV DIY Market!


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## FB Performance Trans (Dec 14, 2010)

> Thank you for taking the time to provide the info I inquired about. I really appreciate people/shops like yourselves, who step up with quality parts and stand behind them. Thank you for your time!
> 
> Ernie





> Thank you for providing your products to the EV DIY Market!
> Browser330




You&#8217;re welcome! We have always believed in providing as much information as possible so that our customers can make intelligent decisions about their cars.

We&#8217;re hoping that if we can produce more of this equipment that it will help to bring the costs down particularly with the adapting components. Although they&#8217;re completely engineered right now they&#8217;re being produced one at a time. 

Mike @ FB Performance Transmission


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## electrc109 (Jan 15, 2011)

on the cars i've converted, i simply removed the clutch and mounted the motor directly onto the flywheel. no clutch since you don't idle. it requires smooth shifting, but it works!


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## Marco (Jan 12, 2011)

You are saying that you leave the flywheel in place. I got the impression that it was no longer required, aka dead weight. I must ad that a gearbox close by also said he is going to leave the flywheel in. Basically stating that it will keep the momentum.


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## FB Performance Trans (Dec 14, 2010)

> *by **electrc109*
> on the cars i've converted, i simply removed the clutch and mounted the motor directly onto the flywheel. no clutch since you don't idle. it requires smooth shifting, but it works!


Hi electrc109
You’re right, there seem to be many options for setting up the driveline in EV conversions. However from what we’ve gathered from the customers we’ve dealt with, they wanted their EVs to have the same drivability as an ICE. As you know in the Automotive Industry there are far more automatics in service these then sticks. Of course, everyone has their own preferences and what they are willing to tolerate as far as drivability goes.




> *by **Marco*
> You are saying that you leave the flywheel in place. I got the impression that it was no longer required, aka dead weight. I must ad that a gearbox close by also said he is going to leave the flywheel in. Basically stating that it will keep the momentum.


 Hi Marco
With an automatic transmission the flywheel is replaced with a much lighter flexplate, but the torque converter that’s added certainly adds more weight and of course maintains the momentum you mentioned. It also dampens the initial shock to the driveline each time the electric motor is restarted.


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## Marco (Jan 12, 2011)

Hi again. Sorry, i did not know that you were talking about automatic gearboxes and reading now what i posted last you must think i am a retard or something..... This shock you are talking about is this also applicable on manual gearboxes? and do i need to keep the flywheel for a manual gearbox?


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## electrc109 (Jan 15, 2011)

no you do not have to keep the flywheel for a manual. an adapter has to me made to attach where the spline shaft where the flywheel would to the motor shaft.


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## Marco (Jan 12, 2011)

Thank you very much for your advice


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## ElectrifiedMonteSS (Feb 27, 2011)

Do you specifically like the Ford AOD and AODE transmissions? Or were they specified bu the customer? I know you mentioned that the Low Gear Planetary set was easier to come by.. Can this be done with a Powerglide, TH350, TH400 or any other GM type automatic?

My first thought for my project was an automatic, then I switched to a manual but most other EV projects using the manual said they only use a few (maybe 2) gears out of the 3,4,5 or 6 speed tranys they are using.. Then I started looking for a 2 or 3 speed manual but those are far and few between and I'm not sure the gearing would be right for an electric motor project..

Sorry for all the questions!


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## FB Performance Trans (Dec 14, 2010)

There&#8217;s never anything wrong with asking questions, especially if there&#8217;s out-of-pocket money involved. We&#8217;ve always found that when a customer has lots of questions that we can answer, it helps them make good decisions about the direction they want to go with their project. 

Over the last 15 years we&#8217;ve become very familiar with both the AOD and AODE (4R70W) transmissions. We&#8217;ve devoted a lot of time upgrading them for variety of ICE applications. We&#8217;ve developed these transmissions and engineered the related adapting equipment specifically for use in EV conversions. The older type transmissions, like those you mentioned use much older technology and are limited to having Low Gear Planetary sets readily available at a reasonable cost. 

We now offer two 3-speed automatic transmissions. Both of these units are based on the original Ford AOD and AODE transmissions. We chose these transmissions because they are readily available. Their strength and durability have been proven time and again and we can custom build them to handle 1000+HP if necessary.

*1)* The AODE is fully automatic with a programmable Power-train Control Module (PCM) where all of the shift points can be varied and set as desired. 

*2)* The AO3 uses a Full-manual valve body where the driver always has total control over the transmission functions. 

The valve-bodies in both of these units are designed to eliminate the normal fluid bleed off, so that the transmission can react immediately to the input torque of the electric motor. They both have the strength and durability to handle the typical torque of these motors in conjunction with the weight of vehicles. Yet they provide a smooth transition when shifting from one gear to next, without the sudden jerking response typically found when using a clutch with stick type transmission.


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## steve k (Mar 1, 2011)

This is all in my mind at the moment; but I am contemplating such a project; and would appreciate your input. Can the auto trans that you speak of handle 27,000 lbs gross weight in a truck driven by an electric motor? I have read that you have overcome the hydraulic bleed down so there is good take off from an electric motor that does not idle when the vehicle is not in moption. I am sure the torque convertor has a lot to do with that, too. Please confirm that or correct me. If your current model isn't up to that task, could you build one that is? I believe an automatic with multiple gears would give me drivability not attainable with direct drive/single speed. It would allow a higher top speed without draining the batteries. It would allow me to reach those higher speeds with less battery drain. I believe it would give me more range in that I am turning less RPM; there fore less electric use. The benefits seem obvious; can you tell me if it's possible? A couple of side questions - 1. What would this transmission weigh? 2.What is it's overall length? Thank you Steve K


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## FB Performance Trans (Dec 14, 2010)

Hi Steve
Both of the (2) transmissions that we offer can be upgraded to handle either more power or more weight. For the application that you've mentioned the Low Gear Planetary set with the 2.84 1st gear would be a definite requirement. I would also think that for this type of application you’ll probably have to use at least (2) 11” WARP electric motors in series. 

We have never come across an application with as much weight that would use just the electric motor with direct drive. A transmission added will definitely make a big difference not only for drivability but for the initial take off from a dead stop as well. It should also reduce amount of current required to move that much weight during each phase of coming up to the desired driving speed. 

The restriction of fluid bleed off has been accomplished by modifications to the valvebody. The torque converter has also been modified, but it’s been done to reduce the stall speed (internal slippage). The converter in this case becomes more of a fluid coupler because whenever the stall speed is reduced the coupling efficiency is greatly increased. This is very important in EV conversions because the electric motor produces a lot of bottom end (low rpm) torque.

Both of these transmissions retain the same OEM dimensions and weight. They’re 31” long with the crossmember location 22-3/4” back from the face of the bellhousing. The billet Alum adapter plate is 1-1/2” thick. The dry weight of the transmission, torque converter and adapter plate is 185 lbs. 

If you have any additional questions you can also e-mail us at [email protected]. 
Thanks
Mike


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## normalmitra (May 11, 2011)

This closely resembles an idea I have been contemplating but lack the engineering background for. I am familiar with a relatively bulletproof two-speed transmission used for racing applications: http://www.brinninc.com/ 
It is a manual shift, but I wonder if a similar result would be achieved by replacing the clutch assembly with at torque converter and replacing the need for a stick shift with an electronic actuator to shift. The advantages that I see are: the size, efficiency and weight are excellent, it is tough and easy to work on and electric vehicles do not usually need more than two gears. I especially like the "Modified Open Drive Transmission" for this application. Used Brinn transmissions can easily be found on ebay, but new units are in the $2000 range.
Maybe I'm giving away ideas here, but your adaptations combined with their product seems like a winning combination...


If it works, I'd be happy to test the final product


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## FB Performance Trans (Dec 14, 2010)

I don't want to burst anyone's bubble, but....
There’s really no need to “reinvent the wheel” by trying to use a torque converter with a stick type transmission. Besides, there’s no accommodation for fluid travel or pressure regulation in the stick. This all controlled in the valve body of the automatic. Beyond that the fluid used in a stick is completely different from what’s commonly used in a converter, and they can't be co-mingled. 

There are many companies like ours that currently build 2-speed Powerglide transmissions that are even stronger then the stick transmission mentioned. (We build our units in different stages that range in capability from 700 to 2500+HP). http://www.fbperformance.com/viewtrans.asp?TransmissionID=77 

All of these units come with a full manual-shift valve body. The difference is we have developed the technology to restrict fluid pressure bleed-off during motor shutoff periods. So they don’t require any external pumping arrangement for typical EV conversions. In terms of overall size they can be built with a standard length of 27 ¾” or the “Shorty” version which is only 19 ¾” long. The transmissions are not only extremely efficient they also weigh only about 100lbs. 

We are currently doing an EV conversion for a 3000# vehicle with a custom built 11” WARP motor capable of producing 800 ft/lbs of torque. So our Stage-2 Powerglide will work perfectly in this application with the properly built converter and adapting components: http://www.fbperformance.com/viewtrans.asp?TransmissionID=56


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## normalmitra (May 11, 2011)

So...as usual I found a way to make something more complicated than necessary?

So is a clutch is not necessary for electric, and a torque converter is unnecessarily inefficient, would it be feasible to use a two or three speed manual and use an electronic actuator coneccted to the transmission shift point to change gears? You could hook it up to a paddle shifter like in high end sports cars.


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## FB Performance Trans (Dec 14, 2010)

Well that could be so, but at least you might recognize that a torque converter set up properly with a minimal stall rpm offers a lot to the drive-line of an EV Conversion. Converters built this way have maximum coupling efficiency to the point where they could almost be considered a fluid coupler. They also offer an important feature called fluid dampening. This prevents driveline from being continuously shocked by the high low end torque of the electric motor.

We offer 2-speed, 3-speed and 4-speed transmissions for EV conversions. Only the 2-speed is restricted to being operated with a full manual valvebody. The others can be fully automatic or full manual. The fully automatics are normally controlled by an aftermarket programmable controller or a stand alone shift control module. If someone wanted to use a paddle type shifter with a full manual unit that’s something that’s already being done with ICE applications.


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## cmfatemi (Jul 4, 2011)

My '90 Toyota pu w/ auto, o/d, a/c, & overload springs just died on me--or, at least according to the mechanic, would cost more to fix than it's worth. I've been thinking of doing an EV conversion for awhile, and figured if it was going to happen, this would be the perfect opportunity. I have several questions:

1) Why can't I just hook the motor straight to the driveshaft and just dump the tranny?
2) In the several EV articles I've read, there's a lot about American trucks (esp. Chevy S10), but nothing about Toyotas, which in LA have to be the most ubiquitous pickups around?
3) If I "should" keep my tranny, are there any adaptor suppliers for Toyotas or does it have to be custom-made, &/or can you do it?


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## FB Performance Trans (Dec 14, 2010)

*Hi cmfatemi*

*RE:* Your questions

*1)* There a number of reasons for retaining the transmission in an EV conversion such yours. Here I’m quoting from what a representative of a DC motor company (Net Gain) recently mentioned regarding a similar inquiry:
_Without a transmission the motors will have a lot of difficulty moving a vehicle that doesn't have a very high numerical rear-gear and is very light weight. Additionally, once the vehicle is moving, the brakes won't be able to stop the motor if there were a catastrophic failure somewhere in your electrical design. *I HIGHLY DISCOURAGE DIRECT DRIVE* except for very experienced racing applications (also, the motors need to spin 2000-3500 RPM to properly cool themselves). Existing standard transmission are the most common and only 2-3 gears are normally used. Automatics (other than those supplied by FB Performance) are difficult to use because they normally allow up-shifting, but not down-shifting (automatically). They also are not as efficient. Direct drive with no transmission should not be considered in a "first build" or a "street" vehicle IMHO!_

*2)* There should be absolutely no reason why you couldn’t use the same techniques for doing an EV conversion in your Toyota pick-up as those used in Chevy S-10 or Ford Rangers. 

*3)* I’m not sure which Toyota transmission you currently have, but we would recommend using an automatic transmission and torque converter that is specifically designed for EV conversions. There are a number of reasons why this is important and it involves things like drivability, ease of installation, and of course the overall efficiency. 
If you could send me a message to [email protected] I would be happy provide you with all of the details.


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## Roderick (Dec 8, 2013)

Hi, I am thinking of doing Jaguar XK8 Conversion and they are all AT. 
I have been reading up on AT trans and EV conversions but there arent many threads that are up to date. 
I was wondering what options you would recommend regards with my conversion. 
Giving my original car weigh just over 3500lb and will be using 11" Kostov alpha motor(250v) which is probably one of most powerful 11" motor out there. 


PS any update with your product lines?
R


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