# What are the benefits of a dual motor setup?



## Ziggythewiz (May 16, 2010)

Coming from the only school in the country to have built an electric car, I'm not sure what additional knowledge you expect us to be able to contibute.

However, speaking as one of many here who attended a school that has built electric cars, the primary benefit of a dual motor setup is more power. Provided your batteries and controller(s) can handle it, two motors can give you nearly double the power of one.

Depending on the configuration, dual motors can also be used to provide 4 wheel drive or enhanced control via thrust vectoring.


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## major (Apr 4, 2008)

EV Student said:


> I'm currently doing a project for my Alternative Energy class involving making an electric car, converted from a gas or diesel consuming one. I am from a school that may be well known in a community such as this, Ponaganset. We are the only school in the country that built an electric car. Its a T-bucket.
> 
> 
> ANYWAY-
> ...


Hi dude 

Never heard of Ponaganset. But there are plenty of schools with EVs. Just down the road from me, Findlay, a high school converted a small pick-up truck, Ranger or S10, nice looking and running. They even had a race class for high schools at the Phoenix Electric Races back in the 1990's. I remember a high school entry from Tombstone. 

Google doesn't bring up much about Ponaganset electric bucket T. No photos. Something about fuel cells. Anyway, cool. A couple members on this board have high school teams or clubs doing electric drag racing.

You should do some research about this. And while you're at it, research dual motors. Not a new concept at all. Some of the quickest EVs in the world have dual motors. One has 4 under the hood. A Japanese school (university) made an EV using 8 motors.

You can find a lot right here on this site. There is a search tool. You're welcome to join the discussion, but don't expect members to do your homework for you 

Regards,

major


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## Nathan219 (May 18, 2010)

Motors are one part of a complete vehicle. Multiple motors can have many benefits from weight distribution to handling. Moving the torque generation from one centralized location you can put the weight where you want it. The downside is, most vehicles are not designed for multiple motors, so you have to radically adapt the chassis to take full advantage of the concept.


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## PhantomPholly (Aug 20, 2008)

Nathan219 said:


> The downside is, most vehicles are not designed for multiple motors, so you have to radically adapt the chassis to take full advantage of the concept.


Or simply do without a transmission.


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## EV Student (Mar 6, 2012)

As for mentions of other schools who did EV cars, I've never heard of it. My teacher said we are the only school. *Shrug* Either way, its not my focus, just something I figured worthy of mentioning.

As far as the benefits of dual motors, there is no research I can find at all. Google didn't help. I checked different EV sites and found nothing but garbage information.

The reason I ask for info on this is I can't find anything useful about dual motors AT ALL. My teacher and all his research glory is clueless and can't find anything either, so he encouraged me to join a forum such as this.



For those who offered info, I've taken some notes on that and I'm going to try looking more into it.
--------------------------------

I do have some questions now though:

Say one motor can handle 1800 lbs. Now lets figure out what we need for the second motor. Do you merely add the sum of the two max weights? I wouldn't assume so. Is the maximum weight for the dual motor set still restricted by the max of the strongest motor?

How do you balance things like that?


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## major (Apr 4, 2008)

EV Student said:


> As far as the benefits of dual motors, there is no research I can find at all. Google didn't help. I checked different EV sites and found nothing but garbage information.


Killacycle, White Zombie, DC Plasma, Crazyhorse Pinto, LemonJuice, etc.


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## major (Apr 4, 2008)

EV Student said:


> As for mentions of other schools who did EV cars, I've never heard of it. My teacher said we are the only school. *Shrug*


http://www.powerofdc.com/photos/2011/ac_miata_start_640.jpg 

West Wilkes High School won the Electric Auto Cross at the Power of DC last year.


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## EVfun (Mar 14, 2010)

I would say the biggest advantage of duel motors is a lot more commutator area, allowing for very high currents for short periods. Duel motors are most often seen in EVs without a transmission.

Of course, there are a number of different reasons for ditching the transmission. 2 motors fit easier if 1 can be in place of the transmission. It is really hard to find a clutch that can take the kind of torque 2 motors and a couple thousands amps can create. It is almost as hard to find a transmission that can take that kind of torque from 0 rpm repeatedly without failure. Getting rid of the transmission will save weight. It is easier to adapt to a driveshaft than to a transmission. I'm sure there are more.


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## EV Student (Mar 6, 2012)

Thats good to know. However I still wish to know how the weight of a dual motor setup is calculated. How would I calculate the max weight's for the two motors?

I want to use a TransWarP9 motor, which has a reccomended max weight of 1800 lbs.

Now could I couple that with a second TransWarP9 and it will add up to a max weight of 3600 lbs. for the vehicle? Or would I need to couple it with a different motor that has a higher max weight, like the Impulse 9 or the Warp 9? Does it even matter?


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## hostage (Aug 2, 2007)

TransWarP 9's are designed to be coupled to WarP 9's just as the CrazyHorse Pinto and DC Plasma have done. Mike Willmon and John Metric have both done fantastic jobs. You might also want to look at Ron Admamowicz's WarP Factor II Camaro that has dual 11" motors. Dual motors will cost you slightly on overall efficiency, BUT you get the added benefit of series/parallel shifting the motors if necessary. You might also consider a gearvendors.com over-under-drive unit.
Enjoy!


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## Woodsmith (Jun 5, 2008)

You have asked a couple of times at least about what weight a motor, or dual motors can handle. I don't understand where you are coming from with that question.

The vehicle weighs what it weighs, the motor, or motors will 'handle' that weight if the transmission is right and you have suitable batteries and controller. The performance will vary though.

If you are looking at doubling the weight of the vehicle then that is whole different question from the pros and cons of a dual motor set up.


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## EV Student (Mar 6, 2012)

Don't worry about it much. I have the info I need.

Thank you everybody. I'm sorry if I was a pain or confusing in any way. I'm still trying to learn all this stuff.


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## DIYguy (Sep 18, 2008)

Woodsmith said:


> You have asked a couple of times at least about what weight a motor, or dual motors can handle. I don't understand where you are coming from with that question.
> 
> The vehicle weighs what it weighs, the motor, or motors will 'handle' that weight if the transmission is right and you have suitable batteries and controller. The performance will vary though.


Hey Woody,

I think perhaps what he may be getting at is the 1 hour rating or in the case of an EV, what current it could handled for extended periods of time. A DC series motor's weight is generally representative of it's 1 hour rating and therefore it's ability to handle a larger/heavier vehicle at a higher speed. You are right that an 8" motor would push a small pick up truck but perhaps only in 2nd gear at lower speeds. A 9" or bigger may be needed to run highways speeds for any duration. . . as an example.

Cheers


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## Bowser330 (Jun 15, 2008)

why aren't more people considering twin/siamese/dual Impulse9's vs. the Warp9's? (like white zombie is using)

They spin faster per volt with the sacrifice of less torque, but since they are DC motors, they still have plenty at 0rpm, especially if paired up with the ZillaZ2K.

http://www.go-ev.com/images/003_07_ImPulse_9_Graph.jpg
2750rpm @ 72V & 450A

http://www.go-ev.com/images/003_09_01_WarP_9A_Graph.jpg
2250rpm @ 72V & 450A

So now adjust this to max voltage for the motors, 192V ( i think)....
192v = 2.67 * 72v

2750rpm * 2.67 = 7,343rpm
2250rpm * 2.67 = 6,008rpm
Variance of 1,335rpm

JR's Dyno showed that @ 147V the Warp9 was only able to draw 1000A up to ~3200rpm, with an Impulse9, generally speaking, this would have been ~22.2% higher rpm, or 710rpm higher for a peak of ~3910rpm.


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## DIYguy (Sep 18, 2008)

Bowser330 said:


> why aren't more people considering twin/siamese/dual Impulse9's vs. the Warp9's? (like white zombie is using)
> 
> They spin faster per volt with the sacrifice of less torque, but since they are DC motors, they still have plenty at 0rpm, especially if paired up with the ZillaZ2K.
> 
> ...


That's an astute observation Bowser, and quite true. IIRC both Black Current III and WZ are using the Siamese Impulse motors. I recall a graph that John Metric did showing the difference and how the Warp had higher torque early in the curve, but the impulse motors were able to carry it out further and higher than the Warp motors. It's the difference in the winding and geometry I guess. For racing, it's a mater of how you translate the power to the ground or lets say, how your gearing (if any) + weight of car is matched to the torque curve of the motor. Perhaps the Warp motors would benefit more from a Gear Vendors overdrive, for example....


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## Bowser330 (Jun 15, 2008)

DIYguy said:


> That's an astute observation Bowser, and quite true. IIRC both Black Current III and WZ are using the Siamese Impulse motors. I recall a graph that John Metric did showing the difference and how the Warp had higher torque early in the curve, but the impulse motors were able to carry it out further and higher than the Warp motors. It's the difference in the winding and geometry I guess. For racing, it's a mater of how you translate the power to the ground or lets say, how your gearing (if any) + weight of car is matched to the torque curve of the motor. Perhaps the Warp motors would benefit more from a Gear Vendors overdrive, for example....


Makes sense, I think John uses a GV overdrive unit...


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## DIYguy (Sep 18, 2008)

Bowser330 said:


> Makes sense, I think John uses a GV overdrive unit...


John Metric does yes (but he didn't start with it), not John Wayland. But Olly does also in Black Current I think as well as Mike's Crazy Horse.


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