Figure 1. Eva Håkansson and her electric motorbike, the KillaJoule. (Image courtesy of evahakanssonracing.com.)
The low-slung snub-nosed bright red KillaJoule, an electric motorbike, hit 270 mph on the Bonneville Salt Flats, setting a world record. It’s not fast enough for Eva Håkansson, its Swedish-born driver and owner. Her goal is to hit 300 mph—or 500 kph.
Unlike every other vehicle going for records on the flats, some with ear-bleeding blasts of rocket and jet engines, the KillaJoule’s power comes more quietly. At top speed, you hear the rush of the wind and the tires crunching salt crystals.
Håkansson does not tire of talking about her electric vehicle, which is on display at the first ASME E-Fest, a series of two-day conferences that features wheeled vehicles. Human powered bikes compete with each other on the Human Powered Vehicle Challenge (HPVC) course on the parking lot. Inside the events, Local Motors extolls the “micro-production” of vehicles.
Although outwardly the goal is a quest for speed, Håkansson’s not-so-secret agenda is also to spread the message that earth-friendly vehicles need not be slow and boring.
The same can be true for female engineers, she winks. ASME’s female students in attendance are eating this up. So is a mom who is anxious to show her daughter a future that does not have to fit a stereotype.
Figure 2. 300 lb of lithium batteries located behind the driver power the KillaJoule. (Image courtesy of evahakanssonracing.com.)
The Bonneville Salt Flats are mostly flat, but not like a tabletop, says Håkansson. To drive across them, you’re going to need suspension—and special tires. Ordinary car tires would wobble and fly apart at such speeds, but the KillaJoule’s tires are made of a hard compound rubber, the custom rims are aluminum alloy 6061-T6 and the wheels are specially balanced for high speed.
Håkansson and her husband, Bill Dubé, a research engineer at the National Oceanic and Atmospheric Administration, have built the KillaJoule with their own hands, sinking as much as $150,000 into it over the last five years. “A very expensive hobby,” said Håkansson. She is quick to thank the vehicle’s sponsors, who have contributed roughly an equal amount.
One of the sponsors is A123 Systems, makers of the lithium nano-phoshphate batteries that power the KillaJoule. Three hundred pounds of these batteries sit behind Håkansson. The batteries are a proprietary design of A123 Systems. Together with an EVO Electric AFM-240 motor and two Rinehart motion systems, the bike produces about 400 HP.
Behind the back wheel, the last few feet of the 19 ft length is used to store Kevlar ribbon chute, which is released by a pneumatic cylinder to slow down the vehicle.
The body of the vehicle houses the two main wheels and an outrigger wheel that adds stability. Over the structure between the outrigger wheel and the body is an airfoil that provides a downward force. Håkansson has found that the current design, which was created to have minimum aerodynamic drag, doesn't generate enough downforce for sufficient traction at high speed.
Figure 3. Håkansson has designed a covering for the outrigger that generates downward force and has printed the covering on a Lulzbot 3D printer that is customized to handle large parts. (Image courtesy of evahakanssonracing.com.)
Håkansson uses Autodesk Inventor for some of the KillaJoule’s parts, but the vehicle’s outside shell is not modeled. Parts of the shell are sheet metal with one bend. But as the current design is encountering aerodynamic limits and the Håkansson and Dubé team has a budget that doesn’t provide room for wind tunnel testing, Håkansson’s only hope is having the KillaJoule modeled so that it can be analyzed with computational fluid dynamics (CFD).
Trying It on
Sitting in the long and slender KillaJoule is a tight fit. It has been custom made for the 5 ft 2 in Håkansson. She invites visitors to sit in the vehicle, but only if they are judged as able to insert and extricate themselves from it. I pass the test and manage to ease myself in. “Want to feel what it’s like?” Håkansson yanks at the racing harness. “Can you breathe?” Yes, I say, making my first mistake. “Then, it’s not tight enough.” She’s not joking. My torso is both compressed and pressed against the seat. My arms and legs can still move—but barely. If I were to drive the vehicle—which I chose not to—I’d have a racing helmet attached via a link to the bike frame to secure my head.
"I would also have to wear a fireproof suit. Oh, in case the lithium batteries explode? I make my second mistake. A Tesla burst into a violent fire in Indianapolis after the drunk driver crashed into a tree and parking garage. “It’s not the same batteries as in the Tesla,” said Håkansson. “The Tesla has batteries that need to get as long range as possible. These are different. They hold a bit less energy, but they are much safer,” she insisted. “I still have to have to wear the suit, though. Regulations.”
The Journey Continues
The KillaJoule is technically a motorcycle with the two main wheels and one more wheel as an outrigger, which has the same effect as a sidecar. The stability of the third wheel is much valued. Håkansson showed a scar on her wrist from an accident racing down Pike’s Peak on a two-wheel electric motorbike. She vowed never to race on two wheels again, but adds with a grin "Perhaps I should never say never..."
The 36-year-old Swede came to the U.S for her graduate studies in engineering, and ended up at the University of Denver, where she earned a PhD in mechanical engineering. Her dissertation: galvanic corrosion. “What does that have to do with the land speed record?” Nothing, she says. Forced to choose between her passions (going fast and saving the earth) and practicality, Håkansson chose the latter. The KillaJoule was relegated to part time. “It was either a full scholarship and a stipend to study corrosion, or I was welcome to pursue my dream of fast electric vehicles—on my own.”
Håkansson’s journey will continue to New Zealand, where she hopes to teach at the University of Auckland. The KillaJoule will stay in the U.S., and will be raced by a visiting Håkansson, who is determined to break 300 mph.
"I am very much looking forward to teaching engineering design,” said Håkansson of her next chapter. “The university is preparing the formal paperwork, so it is not 100 percent final yet. I will be at a top-notch university with impressive laboratories, facilities and very friendly faculty, but even more impressive engineering students. Well worth the move to the other side of the planet!"
With “Gasoline is So Last Century” emblazoned on the side, the KillaJoule brands itself as an eco-friendly vehicle in disguise. With Håkansson at its wheel, fearlessly pointing the bright red KillaJoule toward a speed record, it is also as a role model in disguise.
Figure 4. When asked what superhero she could be, Håkansson said she already is one. “I can already fuse metal.”(Image courtesy of evahakanssonracing.com.)