[ausev] Dual electric motor questions

[Michael Bonard]

Hi,

I am a new member of EVA - DC and I am preparing for a conversion using 
a donor car (to be found..).

I am looking for improving weight, reliability, and efficiency by 
getting rid of the gearbox and differential: I would install two 
electric motors (one on each front wheel). I would drive both motors in 
parallel from the same DC-DC converter output. I am also looking for 
using cogged belts to connect the motors to the wheels shafts.

However, the following question came up:

1. How will the motors torque behave in a tight turn? Since the wheel 
which is inside the turn will rotate slower than the outside wheel, the 
inside motor will deliver a higher torque to this wheel while the outer 
wheel will be driven with a lower torque..  I hope that his torque 
difference will not be an issue in normal driving conditions. Is there 
any member of this bulletin board with this type of experience who could 
advise me before I commit to this configuration? I am pretty confident 
that high speed turns will not be a problem (very low relative speed 
difference between the wheels) but I have not been able to confirm this 
SWAG.. Any recommendation would be VERY appreciated.

2. How will the DC to DC converter react to a dual motor load? Hopefully 
it should not mind if I am not exceeding its rated amperes, but again I 
do not have any confirmation.

3. Is there any member who could advise me on the cogged belt idea? I 
think that it is lightweight, relatively inexpensive, very simple, 
reliable, and allows a 3:1 or more "gear" ratio. I did some research and 
found that today we have motorcycles and ultra light aircraft using 
cogged belts passing 100 HP at 3000 rpm. This could be very promising..

4. What is the best "method" to find a donor vehicle with a dead engine? 
I tried E-bay (not interesting, no dead engine to be seen) - and 
CraigsList - a few hits only. The local wreckers claim they "never" see 
a car with a dead engine (Hard to believe!). Any suggestion?


Thanks for looking at these questions!

Michael