LONGHORN RACING ELECTRIC
Longhorn Racing Electric is a student design team at the University of Texas at Austin that designs, builds, and races a formula-style electric race car. Our mission is to provide students with an opportunity to garner knowledge in the engineering field through hands-on learning in a challenging and innovative environment with other like-minded students.
Electric cars are new, exciting, and revolutionizing the automotive industry. We aim to cultivate interest and education in this new technology and provide our members with a unique, cutting-edge experience. Having an electric car team increases the diversity of UT’s chapter of the Society of Automotive Engineers by attracting people from a wider variety of technical backgrounds.
The 2019 Car
The Real Thing
The 2018 Car
Leap of Faith
This was a great year for our team. For the first time ever, we passed all of technical inspection and were one of only three teams to complete in all dynamic events. We were just short of being design finalists, placing 4th. Overall, we placed 7th out of 30 teams. Careful planning and attention to the rules allowed us to pass A-tech, E-tech, and M-tech smoothly and early on in the week. We encountered a bit of a hiccup with our battery, having to open it up and get it re-inspected, but it didn’t prove detrimental to our performance. We passed tilt, rain, and brake test after quickly overcoming some issues. We were very pleased with our performance in the design event, which was a big step up from last year. Our preparation and readiness to jump into conversations with the judges left us with an abundance to talk about.
Some rain and thunder proved to be a challenge to our car during the dynamic events. Although we were able to compete in all of them, skid-pad and acceleration were plagued with issues involving our inverter resetting each time a wheel would slip. Autocross was fraught with some electrical issues at the start, but thankfully we were able to cross the finish line and put a respectable time on the board. After a scare when we realized our front uprights were bending, Saturday morning rolled around and it was a bit wet outside again. Our plan was to epoxy carbon fiber sheets on the outside. Unfortunately we unintentionally broke one of the aluminum welds on our pedal box. In a rush, we took the whole car over the electric tent for repairs. With endurance close approaching, we opted to focus on finishing the race rather than risking damage. The endurance race was a nerve-racking experience, but our last second repairs enabled us to finish the race. We were even able to pass a couple cars during the race, and our times were respectable. It was a great week in Lincoln for Longhorn Racing Electric.
The Process and Work
Leap of Faith's design began from scratch, with a focus on battery and driver. The battery received a total makeover: we switched from pouch cells to Samsung's 18650 cylindrical cells and changed the enclosure from a large aluminum box to a sleek, lowprofile stainless-steel case. We consolidated most of the control units into two modular boxes, one each for our high-voltage and lowvoltage systems. This modularity significantly decreased exposed wiring and made for easyaccess maintenance and debugging. The chassis design centered around accommodating this new battery and creating a roomier cockpit. We widened the front of the frame to incorporate a standard impact attenuator and to make for a more comfortable ride during the lengthy endurance race. The powertrain package includes a dedicated battery bay for easy installation and removal, and drivetrain mounting that extends beyond the edge of the frame to reduce weight and satisfy our wheelbase requirements. Our car is driven with a single Emrax 228, a highly power-dense motor with a proven track record in electric vehicles. The entire car is controlled with a suite of custom PCBs, each connected by an industry-standard CAN bus and custom telemetry software.
At the competition this year, our team was anxious for our first real technical inspection. During the battery inspection, we wowed many inspectors with our clean battery design and layout. After a day with a few minor modifications, we were on to the full electrical inspection. There we had to troubleshoot some bugs, such as improper grounding on some components and the car taking itself out of "ready to drive" mode. Now, running quite late, and with a little tape road bump, we were cleared at electrical inspection and moving on to mechanical. Once there, the team was quick to troubleshoot some more hiccups, going through in just a few hours. At tilt test we all rode the rollercoaster as our car, driver included, was tilted to a heart-wrenching 60degree angle. Like all good rollercoasters, we were ecstatic after the ride was over and we received our tilt test sticker. At last we had reached the big bad boss of inspection: rain test. With a mere hour left to complete inspections, the team rushed to complete some last-minute waterproofing before sending the car into the danger zone. Failing once, we quickly deduced where the water entered the system (our high voltage junction box), dried it out, and re-sealed x2. Racing the clock in round two, we were once again bested by the rain test, as some of the rain found its way into our battery control unit. After ensuring that the car was safe, we were forced to call it the end of our 2018 Lincoln Electric run. Throughout the competition, the team again and again rose to the challenge, quickly diagnosing problems, brainstorming and implementing solutions.
While coming away from competition with just a few technical inspection stickers might not seem like much, it means so much for a young team and our new car. Armed with everything we have learned this year and the advice received at competition, we are ready to design, build, and race a car ready to take on future competitions. And you can bet we will come back next year to race, rain or shine.
The 2017 Car
The Process and Work
LHRe17 was our very first electric car, and came with a multitude of challenges for our young team. As we began the build, two core ideas emerged: simplicity and robustness. The frame and suspension of LHRe17 borrowed heavily from the designs of our sister team's internal combustion cars. The steel tube frame was the backbone of LHRe17, and the suspension featured a double wishbone, push-rod design. Both were modified and reinforced to accommodate the new electrical components. The bodywork and ergonomics were simple systems, made of simple parts.
Our Power-train used an Emrax228 motor, Tritium Wavesculptor 200, chain drive and spool to put power to the wheels, all well know and reliable parts in the FSAE community. The electronics were the big leap forward for the team. The battery was designed around the A123 Amp20 pouch cells, and manufactured entirely in house, while the car was monitored and controlled with a series of 7+ custom PCBs.
Unfortunately, the electronics still proved to be out of reach when the competition date arrived, and we were only able to compete in the static events at Lincoln. LHRe17 taught our team many difficult, but important, lessons that we are taking with us as we move forward.