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

[NeilBlanchard]

Hi Robert,

Originally Posted by RobertSmalls

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.

The "straight" energy conversion is ~33.4kWh/gal (depending on the type of gasoline you are assuming). If you are going to make electricity "account" for losses of generation and the grid, etc. then you need to do the equivalent thing for gasoline, right?

Energy is used for: exploration and development, drilling, transportation, refining, then more transportation, and then even the electricity to run the gas pump! Of course, you would then also include the equivalent for electricity -- but, if you do a source-to-wheels comparison, I think that electricity will still be the better way to go...

[RobertSmalls]

Neil,

The above figure accounts for the 83% efficient nature of oil exploitation, refining, and distribution. It also uses the 30.3% "lumped average efficiency of electrical production and transmission". Both numbers are from the US DoE.

[NeilBlanchard]

Okay, I think I get it -- they add the "losses" of the petroleum fuel to the energy in a gallon of fuel, and then take a percentage of that and that is the electrical equivalent? So:

1 gallon (of generic gasoline) = 13.4 kWh?

That seems a little skewed, still. That means that electricity has ~3X more losses than the whole petroleum cycle?

Lately, I have heard that petroleum exploration is ~15:1 ROI, and I have heard that the power used on refining alone would be enough to power EV's. Maybe, I'm wrong?

What are the grid losses, typically? I thought I heard it was only 10%; though a while ago, I had heard ~50%...

And they are not counting oil spills, probably?

[The Toecutter]

Damn... I had posted a topic on the evalbum entry without seeing this thread.

This car is extremely impressive, *especially* for the cost. I had thought of using a large truck, aeromodded like Phil Knox's T100, with 2,500 lbs of Trojan batteries in the back to get 200 miles range at 70 mph, but that would never come close to being this cheap... I had discounted altogether the idea of using a small car for such a thing because of the need for structural enhancements to handle the weight.

I wonder what structural mods Dave did to this to handle the weight? I am completely awed by this conversion. $3,000 is a good price... and if he sold these bodies as a kit, I'd be a buyer of one.

The top speed makes sense, given that it is a 72V conversion with no tranny. Up that to a 348V LiFePO4 pack and a Zilla 1k EHV, and see what she does... *drool*

Originally Posted by 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.

It's not hard to believed. do some number crunching and you will see how and why this car performs like it does. It is amazing, but the claims are 100% feasible. Dave just happened to actually build something that can do it.

I think he will set a record with this car as soon as he gets the chance. Imagine if he had $30,000 to dump into a battery pack... The current world record with the Solectria Sunrise will have been tripled if that ever happens.

[Big Dave]

Wow! Absolutely gorgeous work. And well enough engineered to get excellent performance even saddled with kludge batteries.

I wonder if he can work with a VW chassis. I'd love to see a TDI powered version.

[MetroMPG]

That's is definitely amazing.

The best "granny-speed-oh-my-no-brakes!" efficiency I've managed to squeeze from the ForkenSwift, hypermiling the daylights out of it, was 168 mpg-e... but that's around an average speed of ~20 mph, not real world highway driving!

[Gasoline Fumes]

Originally Posted by RobertSmalls

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.

I wouldn't expect any more destabilizing effect than with a normal open differential. Try a pickup truck with a locking diff on snow if you want to experience some destabilizing.

[mcrews]

Ugh.......I polished my headlamps today......

Boy.......that guy sure knows how to upstage a website!!!!!!!

Sorry, that was my inside voice.


wow.

[NeilBlanchard]

Dave Cloud sent some pictures of the chassis and battery packs, during construction:









And a "reminder" of the (more) finished car:





And the descriptive part of the email:

I am installing batteries Monday & Tuesday.

The 80 mile run we did a couple weeks ago was without the plexi-glass boat tail.

I'm still only 60% done with the body, so don't be surprised if the watt hours go down in future runs.

Thanks for your kind words and posting on Ecomodder.

There was some mention there of potential problems of turning with dual motors. My motors are in parallel, not series, so demand is set by the controller not by the RPM of the wheels. There are no problems steering in corners.

The back wheels are 38" apart (outside to outside) for aerodynamic reasons. As a side benefit, however, when driving straight under heavy load, I can take my hands off the steering wheel, turn off one motor, and the car stills drives straight.

[Bicycle Bob]

I wonder if the lack of triangulation has or will cause problems. At least, with a more trike-like rear track, the need for torsional rigidity goes down.