So, despite everything that’s been going on in the world, there is at least one silver lining. People are selling just about anything on Craigslist for some quick cash! There are some interesting deals out there, and by extension, there are some interesting cars on sale. And sometimes, someone is selling an Eco-Racer in the next neighborhood over.
I should probably explain that I didn’t go out there looking for something. In between work, school, and
the existential dread of living in a post-capitalist dystopian nightmare other things, I’m just too busy to take on yet another project.
That changed when my mentor sent me a picture of this:
A local Craigslist ad for a “Electric Prototype Vehicle” hidden in the “ATV-Motorcycles” section, with this photo. Most people looking at this thing would probably have dismissed it as someone’s backyard project vehicle. But of course, I knew better.
This wasn’t some backyard go-kart build. This actually is a prototype “high-efficiency” racer in the same vein as a Shell Eco-Challenge racer!
What is an Eco-Racer?
An “Eco-Challenge Racer” is a single seat, superlight vehicle designed to be as efficient as possible. This means the body is usually made of lightweight composite materials, and designed to be as aerodynamic as possible. The best eco-racers have a drag coefficient around 0.1, which is more efficient than a Toyota Prius!
Usually, these vehicles have a compact powerplant designed to consume 1 liter per 100 miles, or 235MPG! But, electric and even solar-powered racers are common too. These vehicles aren’t necessarily fast, but they’re so small and low, driving them must be a lot of fun!
The funny thing is, I’ve had an obsession with designing and building something like this as a school project. And here was one on sale in our own neighborhood.
I think you can see where this is going.
A Cool School Project
After chatting with my mentor about the listing, I decided to send the seller a message. A short while later, we got into contact. After asking a few questions and learning more about the vehicle, we made plans to meet.
The next morning, we hopped on over and got a good look at this eco-racer. I was amazed at the construction of it! The monocoque is made from cardboard honeycomb sandwiched in carbon fiber, and the cowlings are made from a single sheet of carbon fiber. Even the controls are carbon fiber! The end result is a superlight torpedo of a vehicle! I was so amazed by this thing, I had to know exactly where it came from.
Apparently, this eco-racer belonged to the seller’s sister-in-law. She was a Stanford Mathematician who in the Summer of 2009 traveled to Osaka Sangyo University to assist a student team in designing and building this eco-racer for some inter-university competition. Osaka Sangyo is famous for designing and building highly efficient, record-breaking electric cars and solar-powered vehicles!
The eco-racer that was now sitting in front of me apparently came from an institution with a racing pedigree. Sadly, this was all I was able to find out about the racer from my initial meeting with the seller. Could it be possible that the same minds that built these record-breaking cars from a decade ago built this thing?
After the competition ended and the sister-in-law flew home, the eco-racer showed up on their doorstep some time later. As thanks for her help with the project, Osaka Sangyo University had sent the entire vehicle to her home and paid for all the shipping! From there, she kept in the garage and eventually gave it to her brother-in-law to tinker with. And now, he wanted to give it a new home.
I was pretty shocked that something like this was even in my backyard! I don’t even think the ad was up for a full 24 hours before I contacted the seller! But, how often does something like this even pop up on Craigslist, of all places?
So, I pulled the trigger.
The Eco-Racer comes home
After paying the seller and convincing a skeptical, but intrigued friend to borrow his time and his truck to haul this thing home, we unloaded it and took a good look at its construction. With the cowlings and the wheel covers taken off, its pretty clear how extensive the cardboard honeycomb and carbon fiber construction is! There doesn’t seem to be any internal framing except for the brackets holding the motor and rear wheel assembly in place. Even the upper surface the controls are built on the same cardboard-carbon fiber composite as the belly of the racer.
As advanced as the monocoque and cowlings are, the powertrain is simple to understand and work on. Everything is made from off-the-shelf components. The wheels and tires are from a folding bicycle, and the 100W motor itself is from an electric scooter. The motor is paired with a bicycle chain and a single sprocket turning the rear wheel, and the single rear disk brake is taken from a bicycle as well. Power is provided by a pair of 18-volt scooter batteries controlled by a single toggle switch and a pulse width modulator acting as the throttle.
With this powertrain and the lightweight monocoque, this eco-racer could be capable of 20+ mph! The seller did mention however that the electronics need to be upgraded. After all, the batteries and the motor are over ten years old. Despite their age, the batteries still hold a charge, and we were able to get the eco-racer to move with my 215 pound frame wedged inside the cockpit! With some upgrades, this thing has a lot of potential!
After we were done playing with it, we buttoned up the cockpit cowling again, taped the windows up for extra security, and then lifted the entire racer onto a portable table near the back of the garage. Then we attached the rear wheel cowl with a single bolt and closed up shop. Right now the eco-racer is sitting pretty until I decide which direction I want to take with it.
So, what now?
Now that the Eco-Racer is safe and secure, there are a few things I need to do to it:
- Replace the older batteries:
- Even though the batteries and motor are still functioning well, they’re really old. Since the powertrain is built from scooter parts, I could easily source a pair of new batteries and possibly a new motor. In fact, I could possibly upgrade the motor itself and add a 200W instead of the 100W it’s running now. The most important part is the battery pack, so that will be the first to be replaced.
- Create a new battery mount:
- Currently, the battery pack sits behind a simple panel made from the same cardboard honeycomb and carbon fiber the monocoque is made from. Because the batteries are heavy they don’t move around as much when the eco-racer is in motion, but I still don’t like loose components. I want to glue a simple angle bracket and fasten the batteries against the rear wall of the cockpit. I might even add a metal hanging strap or two secure the battery pack further against the angle bracket and the wall.
- A new seat:
- What am I kidding, there is no seat! That panel I mentioned earlier is what you lay against when sitting in the eco-racer. It’s pretty uncomfortable, so I plan on making a new segmented version that not only hides the battery, but is contoured to the upper back for a little more comfort. In fact, I want to use this as an excuse to see if I can make my own cardboard honeycomb carbon fiber panels!
- Taping the windows back in:
- Since the original tape holding up the windows to the cockpit cowling is starting to deteriorate, I want to replace it with automotive VHB tape. This tape can be really thin and transparent, so it wouldn’t look too distracting and it would fasten the windows better then the current setup. Then, I could add thin tape around the outside of the windows to seal the seams between the windows and the body, Bonneville style!
- Tracking down the history of the Eco-Racer:
- This part might be the most difficult. Aside from what I was told by the seller, there is virtually no history or documentation on this eco-racer as far as I know. The seller’s sister-in-law also couldn’t recall who worked on the project, and the name of the competition the eco-racer was a part of. But, I have enough information to begin looking in the right direction. If the eco-racer came from Osaka Sangyo University, it must have been constructed as part of some sort of automotive engineering program. If that is the case, then it’s just a matter of cross-referencing the timeframe in which the racer was built with who might have been teaching at Osaka Sangyo in something related to automotive engineering at the time. From there, it should be a matter of reaching out and confirming everything about the racer!
My hope with this new project is to have something interesting to show off once Cars and Coffee events start opening up again. This could be an interesting opportunity to advertise the Academy of Art’s Transportation Design Program too! I would love to take a crack at redesigning the cockpit cowling as well. Having this thing will be a great opportunity start learning how to fabricate with composite materials.
The possibilities are endless!
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