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Discussion Starter · #1 ·
Hi all,

I'm starting a new project. It is a 1996 Daihatsu Feroza (Rocky in some countries). I originally bought this car as an ICE project but a TV program staring an electric drag car appealed to both my "green" side and the desire to make the car go fast, at least faster than with the little 70kW 1.6L ICE engine. A little further digging and I was sold. My research has led me to the following design options;
  • Battery pack - 1P48S, 200Ah LiFePO4 ~30kWh
  • 4 PMAC motors (Likely a water cooled version of this)
  • 4 Single speed reducers 6.5:1 Ratio
  • 4 sinusoidal ~144V 400A controllers (water cooled)
  • Tc Charger CAN 6.6kW
Challenges
Conversion from rigid axle to independent rear suspension,
Speedo without a gearbox (local regulations do not permit a GPS Speedo),
Mating motor and speed reducer to the axles,
Learning about electronics, CAN and creating PCBs, and
Staying focused for the 2+ years that I will likely need.

Anywho, I will be posting the progress of this build here but in the meantime, here are some pictures of my baby girl :)

120802


120803
 

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Challenges
...
Speedo without a gearbox (local regulations do not permit a GPS Speedo),
That one is relatively easy. There are aftermarket electronic speedometers which just need a sensor picking up pulses from a rotating shaft, which can be one of the axle shafts, a motor, or even the intermediate shaft in one of the gear reduction boxes; the pulses can result from placing the pickup near a gear, so you don't even need to add a toothed wheel for the sensor. It doesn't matter if the reduction gearboxes don't have a traditional speedometer drive gear.
 

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Discussion Starter · #3 ·
Thank you Brian, I was thinking of something like that. I want to keep the original speedo, so the current idea is to use a pulse sensor signal fed to an Arduino, which in turn controls the speed of a little motor that spins the speedo. Another idea is to use the pulses to drive a tachometer (I have a second one in a doner car) and fit it behind the speedo display.
 

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I want to keep the original speedo, so the current idea is to use a pulse sensor signal fed to an Arduino, which in turn controls the speed of a little motor that spins the speedo.
That should work :) I think there are commercial products that do the same thing.

Another idea is to use the pulses to drive a tachometer (I have a second one in a doner car) and fit it behind the speedo display.
Unfortunately tachs don't have much calibration flexibility (they are generally expecting only 2, 3, or 4 pulses per revolution, for 4, 6, or 8 cylinders), but other than that it works.
 

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Discussion Starter · #5 ·
The fun begins....

I have recently moved the car into the garage, weighed it and put it up on some homemade stands with casters so that it can be moved. As usual, there were a few teething problems with the stands but once in position, they worked surprisingly well, making it very easy to move.

123487


I weighed the front and rear axle weights so that I could get the original weight distribution. To my surprise, the rear axle load was heavier at 672 kg, while the front axle load was 641 kg, giving a total of 1313 kg. To pass an engineering inspection I keeping weight distribution is as close as possible original. I also plan to keep the weight low to the ground by installing the batteries in the transmission tunnel. I also plan to make the battery boxes upside down with the lid as a base and the box inverted on this. This way they should act as a diving bell and be fully submersible, but more on that later.

The next step is to remove all the dirty bits to do with the ICT. I'm looking forward to that :)
 

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I weighed the front and rear axle weights so that I could get the original weight distribution. To my surprise, the rear axle load was heavier at 672 kg, while the front axle load was 641 kg, giving a total of 1313 kg.
That is surprising for any front-engine vehicle, but the wheelbase is really short and the front axle appears to be set forward relative to the engine, possibly explaining the distribution.
 

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Battery pack - 1P48S, 200Ah LiFePO4 ~30kWh
A typical 200 Ah LiFePO4 cell is 182 mm by 71mm by 275mm, or 3.6 litres in volume (and 5.7 kg). So 48 of them will total over 170 litres (and 274 kg), plus space for structure and wiring. That's okay for a 30 kWh battery.

I also plan to keep the weight low to the ground by installing the batteries in the transmission tunnel.
I realize that the transmission tunnel is large for the size of the vehicle, due to the bulky transmission with transfer case, but it should be nowhere near as large as the volume of the cells (perhaps half as much, and oddly shaped instead of a tidy rectangular box). Presumably some of the battery pack will go elsewhere, with only some in the transmission tunnel.
 

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Discussion Starter · #8 ·
That is surprising for any front-engine vehicle, but the wheelbase is really short and the front axle appears to be set forward relative to the engine, possibly explaining the distribution.
Yes, this is right. It surprised me too at first but considering the position of the front wheel, all the way forward, and the back wheel with overhang, it does make sense.

I realize that the transmission tunnel is large for the size of the vehicle, due to the bulky transmission with transfer case, but it should be nowhere near as large as the volume of the cells (perhaps half as much, and oddly shaped instead of a tidy rectangular box).
As luck would have it, the transmission tunnel is like a rectangular box and it's quite wide and deep. It was a very pleasant surprise when I stuck my head under there. I will fit what I can and work out the rest at a later stage
 

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Hi all,

I'm starting a new project. It is a 1996 Daihatsu Feroza (Rocky in some countries). I originally bought this car as an ICE project but a TV program staring an electric drag car appealed to both my "green" side and the desire to make the car go fast, at least faster than with the little 70kW 1.6L ICE engine. A little further digging and I was sold. My research has led me to the following design options;
  • Battery pack - 1P48S, 200Ah LiFePO4 ~30kWh
  • 4 PMAC motors (Likely a water cooled version of this)
  • 4 Single speed reducers 6.5:1 Ratio
  • 4 sinusoidal ~144V 400A controllers (water cooled)
  • Tc Charger CAN 6.6kW
Challenges
Conversion from rigid axle to independent rear suspension,
Speedo without a gearbox (local regulations do not permit a GPS Speedo),
Mating motor and speed reducer to the axles,
Learning about electronics, CAN and creating PCBs, and
Staying focused for the 2+ years that I will likely need.

Anywho, I will be posting the progress of this build here but in the meantime, here are some pictures of my baby girl :)

View attachment 120802

View attachment 120803
 
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