2016 GEM AC Conversion Real World Test

GEM Forum
1

It had been awhile since I did a skitracks run in my new GEM. Today was a beautiful day so here it is.

2016 GEM E4
8Kw AC Motor Conversion
Tesla Model 3 Battery
Rodney’s 12:3 Gearbox
Top Speed today was 52.7 mph

Left the house with 92.5 volts (I have a really hard time getting this battery below 90v… LOL). Ran a 4.5 mile drive, mostly up hill except on my last run down to my house. I arrived home with 91.3v.
So, 4.5 miles on 1.2v = 3.75 miles per volt.(Update below - 1v = 4.5 miles)
If I ran my battery from 98.8v to say 75v (using 23.8v) that would give me a 89.25 miles on a charge.
I think I am good for awhile!!!

GEM
GEM4032×3024 2.72 MB

skitracks
skitracks828×1792 208 KB

SkiTracksSat
SkiTracksSat828×1792 420 KB

@grantwest
@Inwo
@LithiumGods
@Troyin909

1 Like
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You should post some info about the build of this car what was involved in bringing it back to life

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LOL - That would be a long post -
Basically rolling chassis to running car - hand build wiring harness from front to back including fuse block, headlights, turn signals, break lights, running lights, replacement brakes, steering linkages, turn signal, horn, headlight and F/R stalks, Tesla Model 3 battery module 99v/240ah (wired for BMS), Replacement gears from 17:1 to 12:3, 8Kw AC induction motor, Sevcon Gen4 controller, wheels, Tires and spacers.

Love the way came out tho - now it is time to wrap it.

4

With a 12.3 Gear Box I assume you have 24" tires. I get about 9100 RPM

I’M IMPRESSED CONGRATULATIONS!!!

Rodney

1 Like
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@Old_Houseboater
Thank you I corrected the ratio -
Yes running 24" tall wheels and tires.

Update - I let the car sit for a couple hours and the battery came out of it’s voltage slump and sat at 91.5v - so given time, 4.5 miles per volt. - WOW

6

I’m thinking of modifying a Schafer 10.35 gearbox for current Gems (mostly for noise reduction) Do you have any interest?

Rodney

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@Old_Houseboater - absolutely

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I will supply inner axle CV joints and stubs. Are you able to fit and join your outer stubs? Accurate measuring and welding required.

Rodney

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Unfortunately no, I don’t have those tools nor would I know how to do it.
I am an IT guy. LOL - can do almost anything mechanically but not welding.

10

Rodney; I would buy a 10:35 right away.

11

What is different?
Something must use shafts that are correct on both ends.
Are splines different? Or just length?

12

I think I remember something about the output shafts are different size from classic to modern gear boxes.

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@Old_Houseboater -
are you talking about supplying #6 and part of #4? and then I would need to cut my #4 and weld to yours?

Screen Shot 2020-09-21 at 9.32.56 PM
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Exactly I don’t have any access to any new model shafts that I can afford for an experiment unless I can find some takeouts. You would have to attach my stub to your part #4 I will see if I can find a pair of #4s so you would not have to do this. But I don’t have a car to fit one up on and it might be a problem to get the clearance right so it doesn’t pop out or bind

15

The new shaft is pictured correct? Only $159 from polaris.

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@Inwo
You are correct - but I really only need one end -
I am going to take this conversation to email to avoid clutter in this tread.

18

Hmmm

I can get both sides out of 1 shaft if the ends are the same.

Works for me rodneyadiehl@aol.com