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

[basjoos]

Beautiful! It is what I would have done with my car if I had a lot more than $400 to play with. Its the best automobile aero I have seen on anything outside of a few solar racers. The only place where I can see that the aero that could be improved is installing front wheel well skirts, doing some more cleanup on the leading and trailing edges of the wheels, and taping up some of the coroplast seams on the underside. He has a rear wheel boattail, but it could be made more aggressive (extend closer to the ground) and built of inexpensive, flexible materials that could be easily repaired or replaced if they gets damaged by road debris. It looks like he has some visibility out of the rear window, the lack of which is a fault in many aero designs, but is needed if they are to mix with heavy traffic. My local cops would have problems with those covered license plates (especially with the one displayed in the front window). With that stretched wheel base, I wonder how large the turning circle is? From the info on that EV page, it looks like this car was designed specifically for EV competitions rather than for use as a daily driver. If it can go 200 miles on lead acid batteries, I wonder what the range would be on lithium batteries. If it behaves anything like my car, with 3000+ lbs and its low Cd, unless there is some maximum allowable rpm on the electric motors, it should easily be able to exceed 65mph in a coast on any slight downhill.

[AeroModder]

Amazing design, but that curb weight definitely needs to go down. Maybe the next one could be made with lighter materials.

Reducing the weight to a rounded ton could probably take that estimated 18 second 0-60 time and bring it down to 10 and increase the range.

[NeilBlanchard]

Well, I just spoken with the builder, Dave Cloud, on the phone, and he is an impressive guy. He has done about 45 EV conversions, and he is very modest about the Dolphin, or any of his cars. He said this car has a lot of compromises in shape, partly because it keeps the front half of the 1997 Metro.

He did make molds of this car, and I hope he can be convinced to continue to develop it -- it is one heck of great place to start from. Like anybody, he feels like a scratch built car would reduce the compromises.

He plans on doing front wheel skirts -- he's seen your car, Mike, and he likes how you have them bump out.

He's a Maker, as a friend likes to say. Hands on, and do it.

Edit: Here's some performance numbers posted by Dave O'Neel on the EVDL, about the Dolphin:

Dave asked me to post the results but I've been pretty busy since I saw you at the races. Here is a brief recap of our trip to Lacey.

Dave drove the car from his house down to Lacey on Friday, for a distance of
exactly 80 miles, using 179.04 Ah, about 90% of what was available. Max
speed was about 70 mph in Bellevue on I-405. The car was then charged
overnight at the Lacey City Hall, at one of the two charging stations
(simple 110V outlets).

The car was then shown at the Alternative Energy Fair while we raced
electrathons. After the races, I drove the car back to Dave's house on a
slightly different route of 76.2 miles, using 173.58 Ah. Using the nominal
72V, that works out to something like 162.7 Wh/mile. Some of the differences in the two trips besides change of driver, were heavier traffic and rain on the return trip.

We learned a few things about the car, but also about the general public. As
we were driving, some people didn't even notice us. Others matched our speed so they could take pictures or video, even to the point that they were
backing up traffic and almost forced me to take an exit because I couldn't
change lanes. It may very well be on youtube already, but good luck finding
it. Overall reactions were overwhelmingly positive. :-)

So, who's gonna' be the first to find some of that video?

[MetroMPG]

Originally Posted by NeilBlanchard

it appears to be chain drive -- a sprocket is just visible on the outside of the driver's side rear wheel in one on the shots from down low and behind the car.

Aha! I wondered if that's what I was seeing.

Well, he sure appears to have a formula he likes to follow. His chopped white drag Metro was also converted to rear wheel drive via chains (to a solid axle though, I think).

[botsapper]

Come on Insight boat-tailers get 'em done already.

[orange4boy]

Point to point. That's hardcore!

Damn. I almost went to that Lacey alt energy fair. I'm going next year for sure.

I just checked his location. Just a stone's throw from here.

[NeilBlanchard]

Yes, it is amazing! Here's some real world data; posted by David O'Neel on the EV Discussion List:

Dave drove the car from his house down to Lacey on Friday, for a distance of exactly 80 miles, using 179.04 Ah, about 90% of what was available. Max speed was about 70 mph in Bellevue on I-405. The car was then charged overnight at the Lacey City Hall, at one of the two charging stations (simple 110V outlets).

The car was then shown at the Alternative Energy Fair while we raced electrathons. After the races, I drove the car back to Dave's house on a slightly different route of 76.2 miles, using 173.58 Ah. Using the nominal 72V, that works out to something like 162.7 Wh/mile. Some of the differences in the two trips besides change of driver, were heavier traffic and rain on the return trip.

So, ~162wH/mile, on real roads in real traffic, some of it in the rain, and without regen -- impressive to say the least.

I spoke with Dave Cloud (the builder) last night on the phone, and I hope to encourage him to continue to develop this design. I can only imagine how low power consumption it could be with a ~400 pound lithium pack (like maybe the EIG batteries used in the FVT eVaro?), and with a good regen system; again like the FVT eVaro, which gets *all* of it's braking from regen, down to 5mph when the friction brakes take over. The FVT team is at the X-Prize, and I'm sure they will be formidable, with their custom twin permanent magnet motors (0-60 in ~5s) and their custom 20kW gen set. They did all their own battery management, too... They are relatively close, up in British Columbia, IIANM.

We learned a few things about the car, but also about the general public. As we were driving, some people didn't even notice us. Others matched our speed so they could take pictures or video, even to the point that they were backing up traffic and almost forced me to take an exit because I couldn't change lanes. It may very well be on youtube already, but good luck finding it. Overall reactions were overwhelmingly positive. :-)

This car has that effect on a lot of us! We are drooling, despite ourselves. This car is already getting a lot of attention, and there will be more.

If there are more pictures of it from the Alternative Energy Fair, or on the road (driven in the rain is fine), I hope these can be shared, also. If anybody finds some of the video of this car on the road -- please post it!

Dave -- congratulations on an excellent design, and a really sweet build! You are a true Maker, in my opinion. And I'm a definitely not the only one...

[COcyclist]

This car confirms what the experts have been saying about aerodynamics on this website all along. But no disk wheel covers!? Did anyone spot where he is hiding his front turn signals? Beautiful build. It should be super stable with all the weight in the nose. Now if I could just find a diesel SmartCar donor car...

[Phantom]

I think that the front turn signals are in the head light housing but the angle/glare keeps you from seeing them in the pics.

[basjoos]

Originally Posted by AeroModder

Amazing design, but that curb weight definitely needs to go down. Maybe the next one could be made with lighter materials.

Reducing the weight to a rounded ton could probably take that estimated 18 second 0-60 time and bring it down to 10 and increase the range.

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.