Piloting the SMV
The Cal Poly SMV is an impossibly unique feat of engineering. It has a higher ratio of carbon fiber than any Ferrari or Lamborghini, it can drive from Canada to Mexico for under $5, and the driver is by far the heaviest component of the car. Striving to repeat Cal Poly's record-setting dominance, the SMV is the culmination of hundreds of hours of painstaking work by some of the top engineering students in the country, and has seen the improvement of several technologies, such as fuel injection. However, there is one massive flaw in the SMV that will never change; you don’t get to drive it.
In fact, more people have been in space than have driven the SMV. Due to the size and weight requirements demanded by its almost nonexistent drag coefficient and incredible fuel efficiency, there are few students capable of piloting the most advanced vehicle at Cal Poly. Luckily, Laura Kawashiri, the extremely talented driver for the team as well as one of our brightest engineers, can tell you exactly what it’s like to pilot the 80 pound SMV.
Before she can fire up the 5 horsepower Yamaha motor, she must undergo Shell regulations. A full flameproof racing suit, a protective DOT racing helmet, and a fully alert mind. As in any race, accidents can happen, and minimizing this risk is of the highest priority. Next, Laura has to actually fit inside the cockpit, which has barely enough room for even a steering wheel, much less our jumpsuit model. Needless to say, it’s a process that requires balance and flexibility. “Imagine yourself trying to lay down in a bathtub with your knees slightly bent and your chin on your chest” describes Laura, “That's the position I'm holding.” Of course, getting in the SMV is only the first step. Once the paper-thin carbon fiber hatch is latched and the cabin is flooded with darkness, Laura’s experience becomes much more interesting. “Now picture the top of this bathtub is covered and you're driving it down the road at 25 mph, hovering 5 inches above the ground” smiles Laura, shaking her head at the craziness of the situation, “the only way to see outside is through a hole at the front about 10 inches in diameter and two elongated side windows.” Despite her visibility, which is more akin to looking through a cardboard tube than an actual windshield, Laura can’t freely move her head to look around due to safety regulations. “All the while, you can't move from your original position because you're strapped down.” Laura smiles about it regardless of the discomfort, since “mentally, it is truly a thrilling experience. I still get butterflies in my stomach every time I climb into the car and the hatch goes on. Some of the blind spots make it intimidating to drive on a crowded track. But the feeling of riding in a vehicle that you and your friends built from the ground up is definitely worth all of the fear and discomfort, especially when the mileage is decent.”
"You're driving it down the road at 25 mph, hovering 5 inches above the ground"
In order to achieve record-breaking MPG, however, Laura has quite a challenge ahead of her. She uses a special driving technique, an extension of the same methods hybrid cars use. “The driving technique we use is called a ‘Burn and Coast’. The engine is always either off or at full throttle, so there is no idling in between. This prevents us from burning fuel unnecessarily while we aren't accelerating” explains Laura, “I start off burning until I reach our target maximum speed, which is usually about 25 mph. Then I kill the engine and try to coast as far as possible with the thrust from the last burn. Once I slow down to about 12-15 mph, I burn again and repeat the cycle.” This technique has allowed Laura to achieve over 1000 mpg despite the engineering Murphy’s law that is vehicle prototyping. Despite her practice, Laura never ceases to innovate with new strategies, explaining “my new strategy is to burn during the straightaways and downhills while coasting on the turns. I also try to use the brakes as little as I can since we are trying to squeeze as much distance out of our burns as possible.”
The most recent opportunity for Laura to apply her new ideas was at the Lompoc test track in mid-January. Awake at 6 A.M. and fully suited and driving by 8, Laura was more thankful than many of our central coast’s fair weather; the SMV has no air conditioning whatsoever. Though testing was stressful, and the new parts had never really been driven before, Laura had a blast. ” The highlight of the test day for me was being able to push the car to its limits as far as speed goes. During competition, we are solely focused on our fuel efficiency technique, so going max speed is not really optimal” laughs the speed-demon Laura, “now that we have significant time for testing this year, we are trying to gather data on the car's performance through a range of speeds, meaning they wanted me to go as fast as the car would allow and then coast until the car rolled to a stop.” Though the car has only 5 horsepower, the combination of Laura’s slim figure and ultralight composite chassis allows the SMV to reach surprising speeds. “I think I got the car up to 40 mph today, which feels quite fast when you're hovering only inches from the floor.”
"The feeling of riding in a vehicle that you and your friends built from the ground up is definitely worth all of the fear and discomfort, especially when the mileage is decent"
A recent addition beloved by Laura is the carbon fiber steering wheel. Though rudimentary until a new piece is developed, it’s a massive improvement over previous years. “The car's steering system has come a long way from when I first joined the team 2 years ago, but there is still much we can improve” Laura concedes, “right now there is a sort of rectangular wheel that I use to steer. It has a horn, starter, and kill button in somewhat ergonomic positions, as well as a hand lever for the rear brake.” As this body is just a test mule, we left Laura the prototype steering wheel to use. However, her input has been priceless in the design of a new racing steering wheel design; a slimmer, wooden wheel with smooth contours, which should make it much easier for Laura to control the vehicle when she rockets up to 40 mph again.
Though this may be Laura’s last year, she’s not letting the project die on her. For the future generations of mileage-junkies, Laura is working on a myriad of improvements to the cockpit. “The biggest improvement to the car from my perspective would be an actual seat or cushion for the driver. Right now, I'm just sort of laying on a pile of towels at the bottom of this carbon fiber trough” frowns Laura, gesturing towards the barren carbon tube she must lie upon while racing. “This year we are looking into getting something along the lines of a memory foam wedge for me to lean on, so that would be great” she laughs, wondering why we had never done it in years before.
Laura is just one of the incredibly talented members of the Supermileage team. Though she’s sad to leave soon, like all of the team members, she’s carrying with her miles of memories. From flying across the country with friends to solve the ecological challenges of the world, to machining one of the hundreds of custom pieces needed for our ground-up design, Laura and the rest of them team’s invaluable experiences will make the world a better place for us all. In a few years, when our work pays off, Laura may once again find the experiences she found here in the cars of tomorrow. And maybe by then, engineers will have created more comfortable seating for her.