The *Ultimate* Aerodynamic Car? Dave Cloud's "Dolphin"

[gasstingy]

I don't know anyone (locally) who would not laugh at me for driving a car like that. But then, most of the people I know don't really care about the environment, renewable energy, lowering their homes energy consumption through thoughtful improvements, etc.

Since that crowd doesn't translate into Mark's (me) opinion, I would dearly like to have one like this. I hope he shares more about how he did this. At 170 watts/mile (I rounded up for safety), I could make my 40 mile roundtrip commute on 6.8 kilowatts of electricity, which means at 8.5 cents per kilowatt hour, it would cost me about $0.58 to drive to work and back.

A BIG for this streamliner!

[RobertSmalls]

Originally Posted by basjoos

According to his info on EV Album, there are 60 lead acid batteries installed (33 lbs each) for a 1,980 lbs total battery weight. If you subtract that from the 3200 lbs curb weight, it gives a 1220 lbs vehicle weight without batteries. This is a low weight, given that it has the front half of a Metro hidden inside and needs to have the structural strength needed to support a ton of battery weight in that long wheel base.

$7000 spent on LiFePO4's would give as much range as his used lead-acids (which isn't a fair comparison), and bring battery weight down to 375 lbs!

The fair comparison would be against 11 virgin lead-acid GC2 batteries, costing $650 and weighing 748lbs.

Wow, 400lbs of battery giving 200mi of range... that's something you'd want to put in an Insight body, right there.

[Frank Lee]

Imagine... designing and completing a project car, using sound engineering and prototyping principles, relaying accurate, measured performance statistics to those interested, and not stopping 1/3 of the way through to publicly beg for money!

[dcb]

I gotta say, there is nothing wrong with a 3200lb curb weight when you get:
200 mile range
72 mph top speed
$3000 conversion cost!!!

It's almost hard to believe.

[dcb]

I also like the twin motor setup, has each rear wheel driven by its own motor (and controller and battery pack).

I wonder if he could tweak some more acceleration with a series/parallel motor switch.

That is to say, leave the two series wound motors in place, but connect them to each other in series at low speed, and when the battery and motor voltage almost meet then switch them to parallel.

[NeilBlanchard]

I wonder how the "differential" function of this setup happens?

[PaleMelanesian]

170 WH / mile? Wow. Using the conversion factor 35 kwh = 1 gallon, gives us an equivalent of 205 MPG!

[NeilBlanchard]

Oh, further info on that efficiency number: they ran with two strings of 12 batteries; and not the full compliment of 60 batteries. One set of 12 were the 33 pounders, and the second set of 12 were heavier, but the same power. And they are all used batteries...

The conversion factor listed on Wikipedia is 33.4kWh/gal, so about 214MPGe? Just imagine what it could be with 400 pounds of lithium batteries and regenerative braking? Of course, that would require front wheel drive -- and so you could use more efficient electric motor, too!

[RobertSmalls]

Originally Posted by NeilBlanchard

The conversion factor listed on Wikipedia is 33.4kWh/gal, so about 214MPGe?

Or when you consider that power plants can only produce electricity at 30-40% efficiency*, it's 13.4KWh/gal, or 89mpge. Still impressive.

And don't judge it just by the amount of energy it consumes. America's fleet could use a little bit more flexibility when it comes to energy sources.

[RobertSmalls]

Originally Posted by NeilBlanchard

I wonder how the "differential" function of this setup happens?

When turning right, your driver's side engine would rev up higher, and your passenger's side engine would slow down. That might tend to have a destabilizing effect. I guess you could just let off the "throttle" in a corner.