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Old 10-19-2015, 07:21 PM   #1 (permalink)
Alex77tj
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Join Date: Oct 2015
Location: Tijuana Mex.
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Ideas for my first EV.

Hi.
My name is Alex.
I'm in the process of building my first ev.
So i have a couple of ideas for those of you who have do e something similar please feel free to shime in.
My donor car is a 1991 mexican build vw beetle.
Here is one of my crazy ideas.
I want to extend the range of the battery pack or bank.
Since a gasoline engine is less efective in stop and go traffic.
I decided to take a look at the gearing in the transmission to try and take some load off the electric motor and in theory extend the range.
So since i have been a vw nut for many years.
I would try to explain my best.
1st gear ratio is 3.8 to 1
2nd gear ratio is 2.06 to 1
3rd gear ratio is 1.32 to 1
4th gear ratio is .89 to 1
Ring and pinion is 4.37 to 1

So what this means is that on 1st gear you need 3.88 turns of the engine to do one complete turn of 1st gear only.
And to get one turn at the wheels you'll need 16.60 turns of the engine or electric motor.
You may be wondering how i ended up whit this number.
Is real easy.
Just multiply the gear ratio by the ring and pinion ratio.
1st gear 3.8x4.37=16.6 turns to 1 at the wheels
2nd gear 2.06x4.37=9.00 turns to 1 ar the wheels.
3rd gear 1.32x4.37=5.76 turns to 1 at the wheels
4th gear .89x4.37=3.88 turns to 1 at the wheel.
So my idea consists in adding 1.26 to 1 reduction gear boxes at the wheels like the ones used in early vw buses to relieve stress or load on the electric motor.
1st gear on reduction boxes
3.80x4.37x1.26=20.92.
So in theory instead of the electric motor turning 16 times under regular load to get 1 turn at he wheels.
It will require 20.92 turns under less load to get one turn at the wheels.
Second crazy idea is to get one electric motor that has shaft's on both end's
The idea is to use one of those shaft's to powe 1 12v alternator
To keep the main accesorie battery fully charged while driving.
And 2 or 3 36v marine alternators to try to extend the range.





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