THE FAST AND THE FUEL-EFFICIENT
story and photos by Joshua Brown
1:27 pm,
May 5, 2009
This is the third try. Rain falls steadily. The pavement on the infield of the New Hampshire Motor Speedway makes a gray mirror, reflecting the black snout of the racing car like a strange metal shark lurking under water. Seven members of the UVM AERO team stand around their vehicle in dripping raincoats. Grim-faced, they look ready to drown.
“Set?” says the judge.
Brian Leach ’10, the team’s leader, nods his head.
Their car, GreenSpeed, failed this sound test twice already today. At 115 decibels it was five over the limit. After years of work, thousands of hours designing, welding, boring, machining, programming, wiring, debugging, taping, tuning—and, yes, even a bit of nighttime practice driving (check the UVM police log for April 25)—this is no cub scout effort in balsa wood.
It’s a $40,000, 590-pound, four-wheel-drive, plug-in hybrid racing car with a gasoline engine and electric motor that work in parallel, custom transmission, 240 lithium phosphate battery cells that receive power from an all-wheel regenerative braking system—and an advanced control network that keeps all the sensors, computers, and moving parts on speaking terms. Zero to sixty in “about four seconds,” says Thatcher Friant ’10, another team leader.
“These are not like regular formula cars,” Friant says. “You can’t just come up with an outrageously huge battery or gas guzzler. The judges only let you have a certain amount of energy on board.”
Part of the third annual Formula Hybrid International Competition sponsored by Dartmouth College, the UVM car is up against vehicles from twenty-nine engineering schools that have come from as far as California, Texas, Russia, and India. Designers from Toyota, GM, and professional racing organizations wander the garage bays seeking ideas for next-generation cars.
And they also might find a few of the engineers who will build them. Working on the AERO car is already a near full-time job for many of the team’s thirty-one members. Brian Leach, surviving on Pop Tarts and bananas, spent much of his Christmas break in the Votey lab.
“The big picture is to create high-efficiency vehicles that are also high-performance,” Friant says. “That’s where motorsports have to go.”
“We like fast,” he says, “but we get climate change. We see what’s happening to the ice caps.”
Last year, AERO—which stands for Alternative Energy Racing Organization, a club sponsored by the College of Engineering and Mathematical Sciences—won most of the design prizes, but two failed electrical switches kept their car from running. This year, the team members are determined to see GreenSpeed race—especially after they botched their travel plans, and then, in a painful irony, got stuck in traffic and were so late that they were disqualified from the design judging event.
Theirs is the only four-wheel-drive car in the competition and “that means fast, fast acceleration” explains judge Randy Bryan, “this car has a great AC drive, plenty of power, and these guys are smart to put it on all four.”
Yesterday, the car sailed through the electrical and mechanical inspections, passed the skid and tilt tests—no dripping fluids when tipped to 60 degrees means it probably won’t happen in the hefty g-forces of a tight turn—but then crashed head-on into the most mundane of automotive headaches: a bum exhaust.
Now the whole UVM project rests on a few wads of steel wool and bits of jury-rigged sheet metal. The students hadn’t paid enough attention to the rules—“there was so, so much to do at the end,” Leach says—and had to sit out the acceleration test because their car was too loud. By lunchtime, with a mixture of desperation and street-car-smarts, they had ripped apart their exhaust, repacked it, fashioned a noise-dampening baffle, and stuck a small metal hood onto the end of their muffler.
As the engine comes to life it sounds throaty and ferocious. But somewhat quieter. The judge holds out his meter at the prescribed distance from the muffler. Fingers cross.
“104,” he says
.
Suddenly the grim-faced engineers are grinning, jumping and fist-pumping like, well, one might think of a pack of cub scouts.
“Cool. We passed,” says Rob L’Ecuyer ’10, one of the car’s designers. “Let’s drive.”
11:20 am,
May 6, 2009
A green flag drops and Dave McCloskey ’10 zips away from the start line. Two other cars are already working the orange-coned course, hunting for fast laps—or at least mechanical survival—over a snaking sixteen-mile endurance time trial. Within moments, GreenSpeed has overtaken a lumbering brown car from Tufts. It almost seems unfair, like a fighter plane racing a tugboat.
“Whoa. That car moves,” says Brian Noland, a student from California State Polytechnic who is walking the grassy median as a course monitor. He turns to follow the UVM car. “It definitely has serious torque coming through the turns.” Most of the AERO team stands on the back of a flatbed truck cheering.
At the eight-mile mark, McCloskey pulls into the pit for a required driver switch. GreenSpeed’s halfway split, 14:21, is nearly the fastest, just seconds behind UC San Diego and formula-racing-powerhouse Texas A&M. But new trouble is boiling up—literally.
As the pit crew checks over the car, getting it ready for the next driver, Adam Wood ’11, it’s clear that the engine is overheating badly. All the water has boiled out of the radiator: the modifications to the exhaust, needed to pass the noise test, are preventing the engine from venting properly. GreenSpeed is cooking itself.
After a few laps back on the course, the car begins to falter and stall. It stops. The team groans. The engine temperature has gotten so high that a piston melted. The Tufts car ambles by.
But then, as if the soundtrack of a movie has been cut while the action continues, GreenSpeed starts again. It takes off, running in near-silence, only the tires hissing. Wood has switched to electric-only mode and the car is whipping along nearly as fast as before. Now many heads on the infield turn to watch.
Strangely, these few doomed laps, before a final collapse, taste of triumph: the regenerative braking has done its job, the battery system is muscular, GreenSpeed proves itself a true hybrid racer.
At the twelve-mile mark, the car comes to a final stop. Wood speaks to two course monitors who run over to help him push the car off the pavement: “It’s dead. The battery pack died. The engine seized. There’s no water left.” He hoists himself out of the driver’s seat, takes off his helmet, and sits in the grass.
A few moments later, the rest of the AERO team gathers nearby on the other side of a fence, peering through the chainlinks at the now-motionless car.
“It was really moving,” Adam Wood shouts to them, with a smile.
“Power it off,” Brian Leach shouts back.
“Well,” says Thatcher Friant, “we had a good run.”
ONLINE EXTRA
VIDEO: AERO CAR