The team completed three valid runs out of four attempts.
By Rogelio Escamilla
SONOMA, Calif. —The Motorsport team beat their personal record and placed fourth in the Shell Eco-marathon Americas competition April 6 in the hydrogen fuel-cell prototype category.
Although in fourth place in the on-track competition, the team received an honorable mention in the vehicle design category
Last year, the team placed first in vehicle design.
During the closing awards ceremony April 5, Eric Ewald, mechanical engineering sophomore and mechanical team member, won a $1,000 scholarship from Southwest Research Institute.
The previous day, the institute handed out fliers for team members to fill out, which included their name, major and team, and three winners were randomly selected. Ewald was the only recipient from a community college.
In the hydrogen fuel-cell prototype category, the main objective is fuel efficiency. However, if a driver does not complete all laps in 24 minutes, the run is invalidated.
Prototype runs were 8 a.m.-4:30 p.m. PST April 5 and continued 10
a.m.-2 p.m. PST the next day. After the track closed, teams could look at leaderboards online for the final results.
The team completed three valid runs out of four attempts, and during their final run, Odyssey scored its best fuel-efficiency rating ever — 1286.3 MPGe, or miles per gallon equivalent.
The team’s previous record was 945 MPGe.
During the team’s first run, their vehicle Odyssey broke down during lap seven out of eight and was towed off the track, invalidating the run.
The run would have been invalidated anyway because the team passed the 24-minute time limit.
Despite a time limit, the on-track competition is won by the team with the most fuel-efficient vehicle.
The team’s second run was a success; they completed all eight laps in less than 24 minutes, and their fuel cell did not run out.
They averaged 2.52 minutes per lap and reached 903 MPGe, which put them on the leaderboard but other teams beat that efficiency level the next day.
The team was supposed to have a new motor controller delivered to their hotel April 3 or 4, but it began shipping from China April 5. The team still has not received it.
Because of this, the team had to raise the current limit on the motor controller before their second run to provide more speed to make the time limit.
“The motor controller felt better than ever,” said driver Allie Moore, electrical engineering sophomore, during a team debriefing at their hotel. “I wouldn’t change anything.”
After the run, they were one of two teams in their category of five teams to complete all eight laps on time and put a score on the board.
Motorsport adviser Ben Uresti said, “In the past, some teams didn’t make it out of inspections.”
Vehicle failures are common during the competition, which is one reason teams can have a maximum five runs, only the best of which is counted.
The motorsport team attempted four runs.
There are occasions when the number of runs a team can make is limited, mainly because of inclement weather, or if officials prioritize teams who have not had a successful run.
Josh Chavana, mechanical engineering sophomore and team manager, said the team worked on balancing Odyssey’s speed and fuel efficiency before their third attempted run April 5.
“The last run, we were leaning more toward speed,” Chavana said. “We want to make some adjustments to make it more efficient, like making the toe parallel, inflating the tires and stopping the rear brakes from rubbing. We might turn the SCU switch on. If we do, we should get more efficiency.”
Chavana was talking about the short circuit unit that, when switched off, helps the fuel cell stack stay on, but makes it less efficient.
According to technical team leader Isaac Medina, the team initially turned off the SCU switch to ensure the fuel cell’s voltage didn’t drop, which is what caused the first run breakdown.
“To make the efficiency, we fine-tuned the positioning of the front wheels’ toe, or the inward tilt of the wheels, to make them more parallel,” Medina said. “We also turned on the SCU switch and decreased the hydrogen pressure.”
The team also maximized the tire pressure, which is done to lower contact with the road and increases efficiency.
Despite the competitive nature of the event, teams helped one another with spare parts, mostly during the inspections.
Wheat Ridge High School, which placed second in the on-track category, blew a tire three times the day before their April 5 run.
“They came over and asked if we had a spare tire. They put it on and it was a little small, but it worked,” Uresti said. “Yeah, they were one of our competitors, but that’s what the competition is about.”