It’s been a little more than a week since the team’s dramatic third place finish in the 2011 Formula Sun Grand Prix at the Indianapolis Motor Speedway. But our shiny trophy doesn’t tell the whole story. This was our car’s fourth and final competition. And with a brand new electrical system and drastically improved telemetry, it was also the car’s most successful. Read on for a day-by-day breakdown of the race, from initial inspection to the agonizing, eleventh-hour battery troubles that eventually cost us a second place finish.
The race crew left for Indy at 10 a.m., just minutes after Jess Sudo, Matt Filak and Jonathan Cook got out of a midterm exam. After a four hour drive, the crew was allowed to enter the track early because we were one of the first four teams (along with Western Michigan, Iowa State and Minnesota) to submit all of our competition paperwork. (Here’s to vanquishing procrastination!) Throughout the afternoon and evening, scrutineers checked that SC5 met size requirements, that the turn signals and brake lights were visible and functioning, and that our drivers could see well through the windshield and using the backup camera.
Everything checked out great, with the only hiccup being that our backup camera screen was too small to see with properly; the rain and dim lighting certainly didn’t help either. Fortunately this was an easy fix, and we got the go-ahead to continue inspection Tuesday morning.
The rest of the teams arrived very early Tuesday morning for an 8 a.m. all-teams meeting. The final rounds of scrutineering went smoothly, with only a few minor mechanical and electrical changes needed. The battery box needed to be better secured so it wouldn’t wiggle around during the race, airflow within the battery box needed to be improved by plugging a gap near the fan, and we needed to put a voltage sensor on our auxiliary battery pack.
On an especially proud note, the scrutineers loved our new electrical system; they were really impressed by our progress since last year. Then came dynamics testing, which included a slalom test, a U-turn test (driver must turn the car 180 degrees within a certain distance), a figure-8 (normally the driver must drive through the figure-8 at a certain speed, but there wasn’t enough space for a full 8, so we just drove a circle in two directions), and finally a braking test, in which the driver had to slam on the brakes and stop on wet asphalt within a certain amount of time. We passed and got the green light to race.
We were the third team to pass every inspection and so were third on the starting grid. After passing everything, our friendly race crew helped other teams improve their cars. We lent out tools and team members to help the University of New Mexico’s team attach their array to their car and to aid Michigan State University’s team in finishing their array wiring. Then the crew basically hung out and talked shop with all the other schools. As sponsorship chair Jonathan Cook said, it “turns out you can chat about solar cars for hours on end and not even notice it.”
The first day of racing! And just as exciting, Jonathan Cook and chief engineer Dan Cornew turned 21 and 22, respectively. With two birthdays, it should have been an auspicious day to start the race. But when the team got to the parking lot at 6 a.m. to head to the track, they discovered what I am going to term an “opposite birthday present.” Someone had stolen our pickup truck. Major, major bummer. Nothing especially valuable was in it, except our array stand, which the team uses to hold up the 100-pound top shell while pointing the solar array at the sun before and after racing. We also lost our third place trophy from the 2009 FSGP. Despite the distressing start to the day, the race began very well. We did have some trouble with the regenerative braking system. The issue was that the battery pack was too full, so every time the driver used regenerative braking, the battery protection system “tripped” and shut off the car – which is what it’s designed to do if the batteries get too full.
So we were able to pick up the pace and started turning out laps to secure their position at the front of the pack. Going faster, however, meant not only more energy loss but also more tire wear – a lesson we quickly learned when we pitted to switch drivers and had to change all three tires. This realization changed our strategy significantly and gave us a bit of a disadvantage because our car’s design makes changing tires a very time-consuming process. After a day of steady cruising, no problems and a good amount of sunlight, we began charging our batteries early because we knew Friday’s weather would be less than ideal.
Throughout the day, mechanical engineering sophomore Matt Filak summoned his carpentry skills between tire changes and designed a new array stand. Our university pulled through halfway through the day and rented us a truck (thank you!), which we picked up around 1 p.m. and immediately used to get lumber from Home Depot.
During the session of “emergency carpentry,” the team had to balance the top shell on coolers by hand – with the much-appreciated help of the Illinois State team – to keep it angled correctly towards the setting sun. When the new wooden array stand was brought out, it fit almost perfectly on the first try. Go team!
After the car and our supplies were prepared for the next day of racing and packed back into the trailer for the night, the team celebrated Jonathan’s and Dan’s birthdays at a local restaurant filled with pictures of race cars.
Friday began just as early as Thursday, but with a new rental truck in the parking lot and quite a few more clouds in the sky. Luckily, our battery was already almost full, so the overcast weather didn’t set us back. We started the day one lap behind Illinois State and 32 behind Minnesota. Jess Sudo drove first, followed by Kristin Landry. But it was midterm season at Northwestern, so at 3 p.m. Kristin had to get out and actually take an exam. Whew. Camille Bilodeau took over driving, and we finished the day two laps ahead of Illinois State and 30 behind Minnesota. The night ended at – where else? – a Steak ‘n Shake.
The plan for Saturday was to go without tire changes and run the optimal strategy so that the batteries would run out exactly at the end of the race. But the right tire started leaking after an unfortunate run-in with a pebble. When we stopped to change that tire, we realized how much efficiency is lost by badly worn tires, so in the future we may go for earlier tire changes.
Toward the end of the day we realized that one of our battery “bricks” (a string of battery cells) was way lower than the rest of the pack. The problem with that is that the battery protection system shuts off when just one brick gets too low, even if the rest of the pack still has power.
Electrical guru and quick thinker Johnny Sun came up with the solution: bypass the brick so it that the system wouldn’t realize it was too low. This fix took about 30 minutes in the hot pits, which was more than the five minutes we expected but less than the half day it once took another team to make a similar fix. During that 30 minute pit stop, Illinois State passed us to take second place, and by the time we got back on the track, they were out of reach.
It was a maddeningly close race, and we are extremely proud of our third place trophy. The team learned so much, and we’re especially happy that the telemetry – the system that relays data from the car to the team laptop – worked so splendidly.
The crew got back to Evanston on last Sunday, and the team is already working hard on the next car. SC5 may not race again, but it will be making appearances around the Chicago area over the next few months. Keep an eye out for us.