# HPEVS Motor Choice



## losduos (Jul 14, 2017)

Hi,
I am new hear and playing around with the idea of converting my 85 Jetta. Mostly city driving and keeping the 5 speed transmission.
I keep on looking at the HPEVS Motors and am still wondering if I would need a AC-50 as usually recommended or if a AC-20 with the 5-speed transmission would work as well. Car doesn't need to be any faster than before, maybe similar acceleration would be nice. Don't really car about top speed too much, 50mph would be good enough. I wanted to run at least 96V
Any recommendations, suggestions? 
Thanks for the input!!!

Cheers


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## dcb (Dec 5, 2009)

figure you need 20hp for continuous 50mph (just a swag). the ac50 is much better at continuous power. You get many more continuous hp per/lb with the ac50 vs ac20 (just going by the graphs)


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## losduos (Jul 14, 2017)

So to get to the 20hp @ 96 Volts both Motors draw a similar current:
AC-50 ~ 200 A @ 96V
AC-20 ~ 200 A @ 96V
of course the torque and rpm much different. 

So essentially the problem comes down to a AC-20 will not run continuous 20HP but the AC-50 will. Is that correct? Meaning I could not maintain 50mph for a long time with the AC-20!?


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## dcb (Dec 5, 2009)

losduos said:


> So essentially the problem comes down to a AC-20 will not run continuous 20HP but the AC-50 will. Is that correct? Meaning I could not maintain 50mph for a long time with the AC-20!?


That is my guess, looking at the peak and continuous graphs from hpevs for both motors.


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## losduos (Jul 14, 2017)

Unfortunately there is no Info for the AC-34. Is anybody running an AC-20 with a 5-speed and has some experience?


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## onegreenev (May 18, 2012)

losduos said:


> Unfortunately there is no Info for the AC-34. Is anybody running an AC-20 with a 5-speed and has some experience?


Here is the power graph for the AC-34.


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## brian_ (Feb 7, 2017)

losduos said:


> Unfortunately there is no Info for the AC-34.


Sure there is...
HPEVS Peak and Continuous Power Graphs for AC-34

From their standard motors page, just select any motor and there is a link to the performance graphs.


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## brian_ (Feb 7, 2017)

The HPEVS page for the AC-20 and AC-23 says:


> Here is a list of the typical applications for which this motor can be applied:
> 
> • Motorcycle
> • Golf Car
> ...


It's pretty clear that they don't think it is adequate for a vehicle as fast and/or heavy as a car. I don't think either the continuous or the peak power are adequate.


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## brian_ (Feb 7, 2017)

losduos said:


> So to get to the 20hp @ 96 Volts both Motors draw a similar current:
> AC-50 ~ 200 A @ 96V
> AC-20 ~ 200 A @ 96V
> of course the torque and rpm much different.
> ...


None of the _continuous_ performance graphs for the AC-2x show anything close to 200 amps being sustained... so no, it can't sustain a 20 horsepower output. The AC-5x is simply larger, which (given the same cooling system) is required to sustain higher power.


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## frodus (Apr 12, 2008)

From my using the AC20 on my motorcycle, and my experience selling and supporting these packages through my business (www.emf-power.com), I would not put an AC20 or smaller in a car. It would be suitable for a very small car (smart car, mini cooper, etc), possibly, but I would choose at least an AC3x series or AC5x series motor for a car or truck.


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## losduos (Jul 14, 2017)

Thanks guys!
I saw HPEVS recommendation but it's sometimes worth questioning manufacturer recommendations. 
Hope the continuous graphs for the AC-34 are online soon.
I'd go DC but really want the regenerative breaking.


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## dcb (Dec 5, 2009)

the ac34 and ac35 are similiar, the ac35 makes a little more torque and a little less rpm for a given battery voltage and current.

but the ac35 graph will get you in the ballpark.









edit, the continuous change between the ac35 and ac34 is similiar (same size, making similiar power). You can look at the continuous graphs for the ac50 and 51 (similar changes between them) and see they are not wildly different, but they are different, the ac51 prefers 144v (and the ac34 has similiar mods as the ac51).


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## zaraf (May 11, 2017)

frodus said:


> From my using the AC20 on my motorcycle, and my experience selling and supporting these packages through my business (www.emf-power.com), I would not put an AC20 or smaller in a car. It would be suitable for a very small car (smart car, mini cooper, etc), possibly, but I would choose at least an AC3x series or AC5x series motor for a car or truck.


 Hello Frodus,

good to hear that you are working with AC-20. 
I am planning to develop a small car (comparable to smart) four passengers, 
0-60KMH less then 20 Sec. 
Fully loaded mass of 1100KG. 
Using a direct transmission.
Do you think this motor work? 

If you see the cont graph of AC 20 at 36 Volt, the max power is around 6KW. As per one of the Senior member on this post, a car must have around 20 HP (15KW) for driving 50 MPH. So there is a power deficit of 15-6=9KW? 
Can you please advice us here. Thanks


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## Jayls5 (Apr 1, 2012)

zaraf said:


> Hello Frodus,
> 
> good to hear that you are working with AC-20.
> I am planning to develop a small car (comparable to smart) four passengers,
> ...



36v is way too low.

I'm running ~103v, and it's ok on my car that weighs 1240 lbs (minus driver/passenger).

It's not something you could sustain highway speeds on without overheating, though it DEFINITELY gets there easily. I would not put an AC-20 in a 1100 kg car.

Here's mine: https://www.youtube.com/watch?v=W7qHHbTEPa0


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## frodus (Apr 12, 2008)

zaraf said:


> Hello Frodus,
> 
> good to hear that you are working with AC-20.
> I am planning to develop a small car (comparable to smart) four passengers,
> ...


I don't. 

I said:



> I would not put an AC20 or smaller in a car. It would be suitable for a very small car (smart car, mini cooper, etc), possibly, but I would choose at least an AC3x series or AC5x series motor for a car or truck.


I don't think the torque or HP is high enough to push that car without being severely under-powered. Get at least an AC3x series for a standard size car.


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## bluerain (Aug 7, 2017)

On the topic of the ac3x and ac5x, I'm trying to plan for a conversion on my Subaru Domingo (japanese microvan, awd manual trans, weighs about 1000kg, normally has around 60hp ice), fastest it's ever gone is around 120km/h.

With the transmission, would it seem like an Ac3x would work ok or would it need a 5x?

Still deciding between dc and ac conversion, but trying to get input to help.

A pile of these were actually converted in Sweden/Finland so there's some basis to work off in what they perform like;
seems at 72v they do around 80km/h

http://www.evalbum.com/968 72v 88km/h
http://www.evalbum.com/3082 72v 80km/h
http://www.evalbum.com/3811 85v 104km/h

http://www.evalbum.com/1007 higher perf, 115v 141km/h some vid of it

Thanks


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