Re: [Amc-list] ELECTRO-RAMBLER =revisited=

["Swygert, Francis G MSgt 436 CES/CECM" <Francis.Swygert3@xxxxxxxxxxxx>]

I don't know... I think the Jeep XJ would be a great EV ... as a 2WD
only. The 4x4 stuff just adds unnecessary weight and takes up room. 

With the rpm requirements of an electric motor, even a three speed trans
would be great. There would be a high amperage draw at the beginning of
each gear for a short period. A two speed using the BW OD unit would be
light weight and should be acceptable. There would be no trans in front
of it -- for reverse the motor itself would need to be electrically
reversed. Even if the design of the motor doesn't make it very efficient
reversed (I don't know enough about electric motors -- should run either
direction just fine, though the brushes will "seat" in one direction in
some) it won't matter -- reverse is only used for short durations. I
like the idea of using the OD unit because it's all electric, would be
light, and it's automatic. A microcontroller could even be programmed to
cut the power at a certain speed so the OD would shift without letting
off the accelerator. It would be 1:1 at first, then high would be 0.7:1.
So a low rear axle gear could be used to get up to around 40 in high
gear. 

But the more I think about it, the more a multi-speed trans makes sense.
An auto OD (four speed auto) without a torque converter as Jim suggested
would work but take a bit of power to turn. A five speed would work
well, actually. Just gear it low so that in OD the car cruises at 75 in
fifth gear @ 3600 rpm. So you won't use fifth much, and you won't stay
in first long -- big deal! You need something like an early American
with big narrow 15" wheels. The reason they were used back then is the
reason you want them in an EV -- low rolling resistance. That's why
horse-drawn wagons have such big wheels -- the larger the diameter the
less rolling resistance. With one or two hp you need the least
resistance possible! 

I have to admit though, you probably don't want 6" wide tires -- 195R15
is 7.68" and about the narrowest new tire readily available, though it
may have to be ordered. Well, VW Beetle tires can be had but are only
6.5" (165/80R15). A 195/75 is the next size up for tall and narrow 15"
tires, though I think I'd use a 70 series. No other sizes can be found
-- at least not at tirerack.com. A new 6.5" radial should be good
though. You know, this is on instance where 18" 50 series tires would be
helpful -- light weight wheels, low profile, low rolling resistance
205/40R15 tires...

I ran some stock size tires on my original Rambler because a tire store
had some NOS ones in stock and gave me a good deal on them. IIRC they
were the factory oversize 6.85x15 tires. All I know is I went to slow
down to turn into a drive at normal speeds on a wet road (almost missed
turn because of fog on windshield) and the car kept going straight when
I hit the brakes and turned at the same time. I was going a little
faster than I should for a turn, especially on a wet road, but was going
slow looking for a street sign. After that it was G78/15, which is
actually an 8" tire. That was the narrowest cheap tire I could get (it
was 1978-79 and I was in high school -- recaps still available!). Of
course the radials vs. the 5-6 year old bias plys made a huge
difference! 
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