The race car built by Trinity students for the Formula Trinity project has been much talked about on campus since the project launched. This year the team’s car successfully passed all the “scrutineering” tests required to compete in the annual Formula Student event at the famous UK Silverstone racing circuit. This made Trinity one of just 18 teams to fully qualify, and the only Irish team to boot. But what exactly goes into making a machine like this? Well, let’s just say it takes more than grease and motor oil to build a race car. Trinity News talked to Formula Trinity’s electronics team to get a better understanding of the tech involved in the project. Here’s what we learned.
All cars, electric vehicles or not, need a system of electronics and wiring to run, and the Formula Trinity race car is no different. A lot of work goes into making sure the wiring is well laid and the systems well programmed so that the team can make physical repairs and digital adjustments without too much hassle. The actual tech involved is important but not hugely complicated: it essentially allows the engine to run and the team to perform the data monitoring and diagnostic checks key to the upkeep of a race car. So how does it all work?
“The heart of the operation is a small programmable module called the Electronics Control Unit (ECU). This is the central nervous system of the car.”
The heart of the operation is a small programmable module called the Electronics Control Unit (ECU). This is the central nervous system of the car. The ECU tells the engine how to run, and the fuel injectors and spark plugs when to fire. It is also plugged into sensors that monitor the car’s “vitals”: things like engine temperature and revolutions per minute (RPM), AKA how fast the engine is spinning.
The ECU itself is programmable, meaning parameters like those just listed can be adjusted remotely using a computer. For example, the car’s “spark advance” may be tweaked so that the spark plugs ignite at an earlier point in the engine’s piston movement. If the plugs fire too late (or too soon) in the process the engine’s performance is affected, so the ability to finetune the performance by editing this parameter and others like it using the ECU is key to ensuring the car is race-ready.
In order to actually make these adjustments the team connects the ECU to a program called Tuner Studio which they then use to program the available parameters. To do this a computer is plugged into the ECU while the car is stationary (when the team is at the workshop, for example). An alternate method is to connect the unit to the program via. Bluetooth. Using a Bluetooth connection means the computer can be connected to the ECU while the car is running, allowing the team to monitor the engine performance and make adjustments to the parameters as the car is driven in real-time.
“The safety circuit is wired in series, meaning that any break in the circuit shuts the whole system down.”
As well as the ECU and engine electronics, the Formula Student competition rules require the car to have a built-in safety circuit. In the Formula Trinity car, this safety circuit consists of several sensors and three “E stops” (Emergency stops AKA Big Red Buttons). These are all wired “in series”, meaning that any break in the circuit shuts the whole system down – the driver or the team can hit any of the Big Red Buttons to kill the engine in an emergency. The other elements of the circuit include a master switch which is the first thing connected to the battery and kills the engine power when flipped; an inertia switch that functions similarly to the master switch in the case of a crash; and the Brake Over Travel Switch (BOTS) which is triggered if the brake system fails to apply enough pressure.
The engine itself comes from a Honda CBF600 motorbike. As it is an internal combustion type and not an electric engine, the electronics team’s main concerns are the ECU and the safety circuit the competition rules require to be installed. Most of the original sensors in the engine have been kept, along with the spark coils and injectors, but the stock ECU was replaced and all the wiring done was from scratch by the electronics team. After sourcing wires and additional sensors from a local supplier, the team painstakingly built the wiring system – which forms a large loop-like structure connecting back into the ECU – and fit it into the body of the car. In previous years, the ECU itself was located at the back of the car beside the engine, but for the latest competition, the team chose to move it to a box just above the driver’s knee area where it now lives for better access. Making it all look neat is the cherry on top but that neatness does become important when repairs or adjustments need to be made.
So, dear reader, hopefully this article has shed some light on the technology involved in building a student race car. Or maybe you now have more questions than when we started. If that’s the case, have no fear: the race (and year) has only just begun!
