[Ioku]

I am looking for you opinions as to what would be the best drive system for the performance and abilities I am looking to get in an EV. You can also read my thread, EV Rally Car, here http://www.diyelectriccar.com/forums...-car-5172.html to get an idea of what I a trying to do.
What I want out of my EV listed in order
1. Acceleration, I would like to get around 0-60 in 4 sec, or less
2. Handling, I want the car to handle as well if not better than the ICE version.
3. Range, I would like to get about 100 mile under normal diving conditions.
4. Top speed, This isn’t that big of a concern but I would like around 100 mph.

And the car I plan on using will be a 95 Subaru Impreza it is a popular Rally car and I already own one, you can also go here, http://www.proev.com/ to see an already converted 95 Impreza.

Option 1, single motor

In this option I would use I single AC motor connected to the Subaru AWD drive train which would include a 6 speed transmission.
Benefits in my opinion, good acceleration this gear box is already geared for it, having a 6th gear could help with range on the highway and allow a good top speed, handling about the same as ICE, easy of conversion.
Negatives in my opinion, this would mean more moving parts more things to break.



Option 2, Duel motors

In this option I would use 2 AC motors, each one powering its own set of wheels, basically the same as the proev rally car. Benefits in my opinion, better AWD handling and better control of what wheels the power is going to, less moving parts less to beak down.
Negatives in my opinion, possibly less acceleration and lower top speed being locked into one gear, range may also take a hit, more difficult to convert.



Option 4 Quad motors

I this option I would use 4 AC motors each one connected to its own axle, I would do this instead of wheel hub motors to reduce un sprung weight. Benefits in my opinion, possibly the ultimate in AWD handling and control, It could even allow tank like turning abilities by running the right side motors clock wise and the right side counter clock wise it could literally spin on a dime.
Negatives in my opinion, again being locked into a single gear could hurt acceleration, top speed and range, much more difficult to convert.



And on a side note as I use more motors the smaller they would be, so I am not thinking of trying to cram 4 full sized motors in the car.

[Mastiff]

I'd say go with the Single Motor attached to the standard transmission this has the advantages of:
1: MUCH simpler to convert the vehicle
2: You can get VERY powerful VERY efficient single AC motors
3: This retains the same 4 wheel drive handling as the original car
4: This can save on weight because more motors also means more controllers, motors + controllers = weight.
5: This will save on energy.
6: You'll have much better control over what kind of torque and RPMs are on your wheels with the Transmission still attached.

I wouldn't worry about parts breaking unless the 95 Subaru Impreza is prone to breaking, which I don't think it is.

Plus any customized system you have to design will have tons of failure points too, but these failure points are custom, thus YOU will have to fix them or build new parts for them.


If you want serious performance out of one motor I'd buy the "Heavy Vehicle Manual Transmission" kit from Electro Automotive:
http://www.electroauto.com/catalog/ackits.shtml#heavy

They are the only ones I know of that sell that Motor and controller.
It's the one I'd use in my dream EV:
http://www.diyelectriccar.com/forums...m-ev-7747.html


This Pickup EV weighs 5,400 pounds and is powered by one of those motors:
http://www.evalbum.com/1430

It still reaches 70mph to give you an idea of the power of this motor/controller system.(it was designed for electric city buses)

Now your 0-60 time will be more dependent on the weight and C rate of the batteries you use, the ProEV Imp used Kokam Lithium Polymer batteries.

If you can use a battery pack of some Lithium Iron Phosphate batteries, they have a MUCH higher stable C rate, meaning if you had 200AH of power in your batteries you can actually draw x2, x3 or 4 times that power, depending on some packs.

You can try contacting http://www.lionev.com/ for a battery pack, I'm not sure of anyone else who sells lithium battery packs for EV's.


Just my $0.02.

[Coley]

Your target is, at this time, not too realistic with the batteries we have at our disposal.

More drive axles, motors and such will cut the range and accel.

Unless you have an unlimited budget for the car, you may have to go a little less fast and not so far in distance.

But that is just my opine.....

[Ioku]

Thanks for the links and advice Mastiff, I was also thinking that a single motor would be best from what I have read, but wanted to see what others thought of the more wild Ideas. And as for batteries I'm just going to wait before I decide on any because of how fast the technology is changing.

[Mastiff]

Ah I remembered Valence (http://www.valence.com/), here's a topic discussing them:
http://www.evdl.org/archive/index.ht...ble-td15120633

Here's a list of EV's built with Valence batteries:
http://www.evalbum.com/battb/VALN

The Solectria Sunrise was built with Valence batteries.
I'm not sure if they're well suited for performance EV's but it seems like they sell a full battery pack and BMS and since other people have made EV's with them you know you can get your hands on them.

[david85]

I would recomend sticking with the motor that they already used on the proEV race car. The Azure Dynamics motor that electro carries is not very effiecient for an AC motor (none of them are in fact). With the controller at a mere 83% effecient (according to electro's specs) you would be better off with a DC brushed motor. The AC55 motor is also air cooled wich kills some potetnial horse power potential. Azure does carry an AC90 motor, that is in the low 90s for overal efficiency, but its a real pig for size and wight. They do design their motors for HD application, but the power to weight ratio make it more sutable for shuttle busses and other low speed vehicles that don't have to go very fast.

The siemens 5134WS20 AC motor on the other hand is available with a 98% effiency controller (brusa), with the motor itself being a little over 90%. And since its water cooled the continuous rating will be higher.

[MitchJi]

Hi,

This Volvo uses 4 motors:
http://www.pmlflightlink.com/news_volvo.html

There was a recent interview on Autoblogreen in which a Volvo Executive said one thing holding them back was the difficulty of controlling 4 motors. So I think you might be better off with a simpler (single motor) system.

Mitch

[MitchJi]

Originally Posted by david85

The siemens 5134WS20 AC motor on the other hand is available with a 98% effiency controller (brusa), with the motor itself being a little over 90%. And since its water cooled the continuous rating will be higher.

Hi,

It also costs almost twice as much.

Mitch