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The Formula SAE senior design project was truly unique. This project had been a 5 year long process to design, build, and test a raceable car. The car was this team's prototype. While the original plan for the team was to develop an energy recovery system (ERS), this scope was altered because of the state of the car the team was left with. Upon examination, the car needed a lot of work before it was even going to start. Therefore, without a running car, there was no way of appropriately testing an ERS. Furthermore, had we developed a prototype for the ERS, there would have been no way to truly implement the design. It would only have stood as a proof of concept. Ultimately, the work required to start the car and develop and ERS would be a task that required two teams.
By making the change in scope, the team had been the closest to date to achieving a running car. Currently the car does not start. However, the team was able to get the engine to backfire in an attempt to get it to start. To get the full state, the issue has been identified as the engine control unit's (ECU) inability to get an accurate camshaft sensor reading. With a hardware adjustment, the team was recently able to deliver a reading to the ECU. It outputs a correct square wave, but its periodicity has yet to be tested. The team has left to test the new hardware with the engine. In order to get to the point where the car is in position to start, many major subsystems required re-working. These systems include the wiring of the car, the fuel injection system, and the engine control unit (ECU). First, upon receiving the car, its wiring was incomplete, and very unorganized. This was no easy feat to correct. Furthermore, wiring of the car was particularly challenging because the team had to develop its own wiring schematic that combined the wiring schematics of the 2007 Phazer snowmobile engine and the schematic of the MegaSquirt II ECU. Additionally, the team had to include adjustments to the schematic that included the primary master switch (Required by FSAE rule IC.9.3) and cockpit main switch (Required by FSAE rule IC.9.4). Next, the fuel injection system was not correct. The fuel system that the original snowmobile used was an in-tank fuel system. However, the car requires an in-line fuel system. The differentiation between these two fuel systems was critical because they each require different types of fuel pumps. The state of this subsystem when the team received the car was incorrect. While the set up was correct (an in-line fuel system), the pump used in the system was an in-tank pump. Additionally there was no fuel filter. The team was able to acquire the appropriate pump and a fuel filter for an in-line pump system and completely changed and corrected the fuel injection system. Lastly, the ECU was the most challenging of the subsystems to correct. The ECU acts as the brain of the car. It interprets the sensor readings all throughout the car and responds with signals so that the car can time itself appropriately, start, and turn-off when it needs to. The first step towards completing the ECU was to install its two daughter boards. These were vital because they help to interpret the certain sensors that are specific to the Phazer engine (i.e. the VR sensor). Next, programming the ECU was critical. While there was a code provided specifically for the Phazer engine, it required tweaking. All of the program installation and critiquing was done through TunerStudio. This was the most challenging of the major subsystems because it was the topic that the team had no prior experience working with. However, the team did extensive amounts of research and had many conversations with experts to understand how to best program and implement the ECU.
It is important to note that this report is written as the car currently sits. That being said, it does not start. However, there is still time for the team to get the car running. The final step towards doing this is to make sure the hardware adjustment carries over appropriately to the final trial start of the car. Once it does this, the engine will have no issue injecting the fuel, and igniting its sparks (both of which have been tested and work). With the current status of the car understood, it is important to note that all design constraints, and applicability codes and standards were met. While the team's most pressing constraint was time and money, neither has put a hindrance on the team working on, and improving the condition of the car. The codes and standards that are most applicable to the team were those provided by the FSAE rule book. However, there were not many regulations that regard getting the car to start. As mentioned it was important to include the master switch and emergency shutoff switch in accordance with the code. However, not much else was required for the team to get the car to start. It will be important for future teams to dive deeper into these standards as they get closer to racing the car. Primarily for the safety of the driver, but also, by not following the rule book, the team will be disqualified. Additionally, it will be helpful for future teams to refer to the design manual produced by this year's team. It will encompass what has been completed by the team and what is left to do to get the car competition ready. Overall, the team progressed greatly with the car and has high hopes for the future of the FSAE senior design project.
Bucheli, Carlos; Hensley, Patrick; Arias, Tristan; and Ulmer, Max, "Formula SAE" (2022). Engineering Senior Design Reports. 54.