Our Cars

First full funtionality finishing car

The ER25 was built to achive a goal that has exsited since the beginning of our organization: finishing every dynamic event at competition with full functionality intact. While out previous cars had shown potential, this specific milestone had never been reached. Building on the ER24 platform, the season was focused on finalizing a reliable vechicle while targeting a 10% weight reduction.

To ensure a stable foundation, we retained the 600V battery pack and the Emrax 228 High Voltage motor, which provides 110 hp at peak. A primary mechanical focus was the drivetrain; we redesigned the drive axle angles to eliminate the joint failures that had sidelined the ER24. Most of the technical progress this year was software-driven. We implemented a new accumulator DC controller for more precise power management. During testing, we identified drivetrain oscillations and vibrations, which were resolved by adjusting throttle actuator curves, differential settings, and motor maps.

The production phase hit a major roadblock when the frame returned from painting and was found to be a few millimeters too small in the leg volume to meet regulations. This required the team to cut into the finished frame, re-weld the structure, and repaint it. Despite this delay, the team moved quickly into an extensive testing season. We logged miles at Mantorp Park, the Biltema parking lot, Sviestad—where we lost the front wing during a show run—and "Mexico." This track time was used to validate our software changes and provide driver training that hadn't been possible in previous years.

At Formula Student Netherlands (FSN), the ER25 weighed in at 239.5 kg, a 20 kg reduction from the ER24. We passed scrutineering early and officially became the first car in the organization’s history to finish all dynamic events with full functionality. This also marked our first-ever successful electric Endurance finish.

We then moved to FS Austria, where the car’s weight rose to 241.5 kg due to necessary on-site fixes. After replacing worn dampers and passing a lengthy technical inspection, we faced severe accumulator heat soak during the endurance event. With the battery safety shutoff set at 60°C, the pack reached 57°C in the final laps. This led to heavy thermal throttling, making it difficult to climb the track's inclines. To test the car's absolute limits, we used a "kill" map to maximize current draw and monitor SOC drain per lap. The ER25 held together and crossed the finish line, achieving back-to-back Endurance finishes and finally fulfilling the organization's long-standing goal.

Work on the electrical system continued during ER22 and, due to the car not being able to be tested, it was decided early on to try to build on and improve the already existing systems to reduce the workload. The biggest mechanical development would be making a hybrid chassis with a half-monocoque front and a steel frame at the rear.

In order to reach ER23’s goal of having a running car at the races, the team carried out a major recruitment drive in the fall semester, which resulted in a new record number of members at a whopping 125. The challenge, however, still lay in the lack of electrical knowledge around high voltage. This therefore led to the fact that even during this project, as before, the team became completely dependent on a few people who took on a very large responsibility.

During this year, several obstacles were encountered. The first was that we got rid of the cloud storage of all CAD files at the beginning of the project, which of course made the project more difficult. At the start of production, the chassis was delayed in several ways, which ultimately resulted in two steel frames being bolted together instead of the original plan. Because of this delay, even the electrical team and especially the high-voltage team had even less time to set up and test their systems.

On June 6th our inverter broke and since it is a very expensive part we had not had one in reserve. We thought here that the project came to an end with only one month left until the first competition start. In the blink of an eye, we contacted the manufacturer and had it sent down to Germany where it was repaired. However, this set us back about three weeks.

At least we made it to both competitions where FSN was first. With tornadoes and thunderstorms expected, it was clearly going to be an eventful race. The electrical was further worked on and the mechanical was approved. Unfortunately, not everything could be fixed and we therefore only participated in the static moments.

Our second competition was FSUK where we passed both safety and tech scrutineering. Elscrut went well and only a few things remained before it could have been approved if the accumulator was in. Unfortunately, the PCB that controls the voltage indicator on the TSAC broke and the time was too short to fix it. We fell short of the finish line but still feel satisfied after this challenging year.

The change towards electric mobility is not only visible on the streets around us; the Formula Student competition is changing too. In 2019, Formula Student Germany announced that the combustion class will be phased out over the coming years. We in LiU Formula Student did some early studies to investigate the change towards EV, but never fully committed to an electric car. Until 2020.

With the onset of a global pandemic in March 2020, all physical work on the ER20 car was stopped and the university went into distance mode. The newly elected ER21 management, together with the ER20 management, decided to use the time at home to start developing ER21. And with half a year of extra time, we committed to go electric.

The main goal of ER21 was to develop competencies to design and build an electric race car. The car should be as simple as possible, therefore a single motor in the rear and a conventional drive train with differential was chosen. The suspension was only slightly modified in comparison to ER20 and the aerodynamics package was further improved. Preassembled modules were used for the battery and an own battery management system was developed.

Both the change to EV, as well as the COVID-19 pandemic challenged us throughout the year. While we were able to finish the car mechanically, the integration of all electric circuits gave us serious headaches and ultimately ended in us not being able to finish the car in time for competition. Still, LiU Formula Student took a huge leap towards electrifying our organisation and laid the foundation for future success.

The main technical goal for ER19 was to improve the drivability of car; this ambition influenced every design decision made during the fall. The powertrain was designed to deliver a smoother powerband, while maintaining similar peak power figures. Data collection increased in order to monitor the car behavior and draw parallels between driver feedback and performance trends. The driver position was adjusted with ergonomics in mind. Front and rear suspension was fully redesigned in order to enhance kinematics and cornering behavior. Consequently, the frame was also redesigned to accommodate the new suspension pick-up points. The torsional stiffness of the new design was significantly higher than previous years.

The vehicle also marked many firsts for the association: in-house made full prepreg carbon fiber body panels and a partially 3D printed Inconel 718 exhaust system to mention a few. During the summer of 2019 the car competed at FS Netherlands, where an 11th overall placement was achieved. Two weeks later the car competed at FSUK, where the team finished 19th.

For 2017, the team focused on going from the four cylinder Honda CBR 600 to the much smaller and more compact KTM 450 engine. A lot of work therefor had to be done toward redesigning the powertrain, leading to the design choice of keeping the suspension and frame geometry of ER16. Instead work was shifted towards optimizing manufacturing, with the introduction of lasercut steel for the frame and watercutting for low manufactoring cost as well as a new body and overall look. In the end, the car weighed 23 kilos less than its predecessor and competed in Formula Student UK 2017 where it finished all events for the first time in LiU FS history and finished 18th place.

With a new focus in reliability and testing time, the team restarted for 2015 and had ER15 running well in time for the competition. With a spaceframe and the (at the time) tried and tested Honda CBR600 engine, the car was again a simplistic design; but this time with added wings and an aerodynamic undertray. The focus was set on DFM, or Design for Manufacturing, to enable short manufacturing times and enable multiple suppliers. This car competed in IMechE Formula Student 2015, and scored the team’s highest Design event score yet with 105 points.

With one car already being built and competed, the bar was raised for 2013. Instead of focusing on just getting to the competition, the team wanted to be competitive as well. The team focused on in-house design and weight saving, shaving of circa 70 kilos in the end while still keeping the spaceframe, 13” wheels and a 600cc four-cylinder engine (this time the Honda CBR600)! Components designed by the team included throttle body and mechanism, steering rack, steering wheel, wheel centers and ECU/datalogging system (with a great amount of assistance from FreeEMS), in order to increase understanding and have better control of the design and manufacturing. The team competed at two competitions this year as well, at Silverstone (IMechE Formula Student) and in Helsinki (Baltic Open).