Race Day Three

Electrical System, Featured, Solar, Texas / Tuesday, July 19th, 2022

Going into Race Day three, we had a significant lead, filling the team with excitement and a tad of apprehension. The previous day we had set a new day lap record of 227 breaking the record we had set just the day before. Expecting the highest temperatures of the entire race, with temperatures reaching 111°F and track temperatures even higher, we had to prepare both our strategy and our car.  

Following the events of the preceding day, we arrived at the garage to set up the pit, and prepare the car. This included both our usual cleaning of the panels, taping of the underside, checking and adjusting tire pressure (now lowered to 80 psi to account for expansion due to higher track temperatures), and taking down the panels, as well as finishing fixing the fairing, sanding down the epoxy and fiberglass patches and taping other imperfections. 

Lexi Lee (11), Teddie Blahous (12), Opal Heltzel (11), and Hai Lin Truman (11) adjusting brakes and fixing horns while charging in the afternoon.

After we finished setting up the car, we lined up at the entrance, to be the first on the track once again. The first driver of the day was Opal Heltzel (11) driving for the first time in our team’s car (previously having driven for Plano). After acclimating to the car and the higher speeds for a few laps, we were cruising at about 80 kph (50 mph). After two hours and a few pit stops to fix our radio and turn on the motor controller fans, it was time for Hai Lin Truman (11) to get into the cockpit.

Hai Lin’s drive finished off the first half of our day, and we took our lunch break, taking the time to additionally replace our horns and adjust the brakes.

Our afternoon shift was going to be hot. Although race rules dictated that once the heat index reached 95 degrees drivers had a max time of two hours, we decided, for the safety of our drivers, we would cap time in our car at an hour and 20 minutes. The driver rotation for the rest of the day would be Timothy Jou (10), Alexis Lee (11), and Maya Peña (12). While rather uneventful, unfortunately while Alexis was driving, both our horns failed. The rules dictate their continual use while passing. Passing is constant for us because of the high speed difference with the other teams, so we had to pit again to change them. 

Back on the track for the rest of the day, the team was once again able to complete over 200 laps for a total of 672, unofficially breaking the previous total lap record set by the RAHS 2019 team. In just three race days! Although there may be changes to this number for penalties, this is a remarkable milestone for our team to reach.

At the end of the day, there were a few fixes to be made to the car along with our usual routine of propping the solar array: fixing our radio, changing our horns, and adjusting brakes once again. The radio was an easy fix, so were the brakes and horns after some grunt work. Unfortunately, in the process of changing the horns, in the sun (in order to charge the car at the same time), we noticed that our battery had stopped charging, despite all the panels being on. 

In the course of changing our horns, we had opened the side panel and exposed our battery to direct sunlight during the already blistering hot afternoon. This caused the battery to overheat, and the BMS (Battery Management System) to halt charging. Thankfully, a barrage of fans and bringing the car into the shade was able to rectify the issue, and we were able to continue charging. 

We are grateful to Will Jones who served as our team judge today. He helped clarify our questions about the race, inspired us with stories about his experience during the Solar Car Challenge and at Michigan, and was generally approachable and kind.

With the last day on the horizon, the team put the car to bed, ready for a wonderful close to the race. 

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