Make your project car faster: Advice from a Formula SAE team

1. Fail-Proof Your Car

Photography Credit: J.A. Ackley

No matter how regularly you check the nuts and bolts of your race car, it always seems like you miss one. Plus, a fastener can loosen in between those checks over the course of a race weekend.

UF marks all tightened fasteners with a paint pen–a witness mark does it. This provides a very visual check to prevent a $1 bolt from costing you thousands of dollars–and possibly a win.

The team also uses pins on their wheel nuts for two reasons: to provide that necessary measure of safety as well as a visual marker for a developing problem. 

As an additional fail-safe measure, the wheel nuts on the right side of the car have left-handed threads. This helps the wheel nuts self-tighten while the car propels forward.

2. Read Between the Lines

Photography Credit: J.A. Ackley

Some of the best race engineers understand what’s not said in the rule book rather than what is. Case in point: UF’s rear wing, which consists of multiple elements.

“The logic behind this design is mainly due to the restrictions with the rules,” says Cam Lott, lead aerodynamics engineer for Gator Motorsports. “There is a very small area in which aerodynamic devices are allowed, and to maximize the effect of downforce gained from the rear wing, a design with multiple elements was chosen so that the boundary layer for each element was reenergized. Essentially, this allows wing elements to reach angles of attack of nearly 90 degrees, and the pressure differentials between the elements can all work together to achieve the best aerodynamic efficiency desired.”

3. Don’t Forget What’s Under the Car

Photography Credit: J.A. Ackley

The bottom of your car matters just as much as the top, especially when it comes to aero.

“The rear diffusers that attach to the floor of the car are quite special and unique for the design of our car,” Cam says. “The rear diffusers do play a large part in the aerodynamics aspect. What they do is basically allow a large pressure gradient to form by creating multiple growing vortices through the use of ground effect aerodynamics combined with important geometric angles and vortex shielding. A grassroots racer could absolutely improve their aero through playing with diffusers, but a lot more goes into play when considering the aero underneath their cars.”

4. Weigh Your Sacrifices

Photography Credit: J.A. Ackley

Are you carrying too much extra weight? UF looks at everything, including the battery. 

“The battery only has to be large enough to run the starter motor for a few seconds and to handle peaks in power draw,” explains Luke Magno, Gator Motorsports lead electrical engineer. “When running, the alternator can keep up with the power usage of the car–except for peaks caused by the ABS when braking. The battery we most commonly use is actually quite oversized, because the slight weight increase is worth a few extra startup attempts in the event the engine stalls during a race.”

5. Information Is Power, Part 1

Success doesn’t have to take a lot of money: Mark those fasteners, dive deep into that rule book, and work to make the car easy to use. UF’s steering wheel, for example, broadcasts all the necessary info. Photography Credit: J.A. Ackley

Not enough time to plug in the laptop at the track? UF’s custom steering wheel instantly provides a wealth of information at the team’s fingertips.

“In the pit, the steering wheel has various pages of sensor data: everything from tire and brake temperatures to brake bias and corner ride height,” Luke explains. “At the [Formula SAE] competition, we mostly use the steering wheel data to help in the inspection of the car.”

The display broadcasts selected gear, speed, oil temperature, oil pressure, fuel temperature and battery voltage. The wheel also flashes warnings at the driver if those measurements exceed parameters set by the team. (The wheel can also be used to adjust settings such as traction control, launch control and pedal maps.)

6. Information is Power, Part 2

Photography Credit: J.A. Ackley

This Formula SAE car features a lot of sensors–several dozen of them. The sensors fit in one of four categories.

Critical sensors measure oil temperature, fuel pressure, gear position, timing sensors, throttle position and pedal position.

Problem-detecting sensors track brake temperature, oil pressure, coolant temperature and fuel pressure.

Other sensors are used for controls, such as lateral and longitudinal acceleration, yaw rate, brake pressure and wheel speed.

The remaining sensors are used for “tuning, validation and characterization.” These include GPS data, suspension damper position, push/pull rod force measured with strain gauges, steering wheel angle, steering wheel torque, pneumatic shifting pressure and airspeed measured with a pitot tube.

“We use sensors everywhere that we can. Collecting data and then analyzing it is the best way to validate our designs and to tune our car,” says Luke. “We use this data to check for issues and adjust parameters so we can be faster as well as for drivers to see where they can improve.”

7. Information Is Power, Part 3

Photography Credit: J.A. Ackley

Data is useless if you don’t do anything with it. After each run, the team funnels its data into MoTec i2 software on a laptop, which they call a tracktop. Then, they go to work.

“Some of the most valuable data is from the most critical systems for the car to run, which is mostly from the engine,” Luke says. “This data lets us tune and look for problems during and after test sessions. When everything is going well during testing, most of what we look at is for driver improvement and for whatever we might be tuning.

“If we are adjusting shifting timing, we are going to look at shifting requests and the output statuses. If we are tuning suspension, we will be looking primarily at damper positions.

“Certain things, like generating a map of the track, can be helpful for the driver to look at and for overlaying other data on top of, such as lateral acceleration, DRS state or traction control activations.”

8. Don’t Discount Driver Feedback

Photography Credit: David S. Wallens

One of the best sensors is the one you can’t buy out of a catalog or plug into a computer: the driver.

“Driver feedback is an important part of decision-making and tuning,” Gator Motorsports President Jack David says. “We pair it with the data being reported from the car and make a decision based on that combination of information.

“In the earlier stages of the car’s life, we use the drivers to help debug the more noticeable issues and get the car to function as a cohesive system. Then we transition into fine-tuning and honing into a competitive car.”

9. Be Resourceful

Sensors. Computers. Carbon fiber. Discarded beverage cans? Yes, technology does wonders, but resourcefulness pays off, too. Photography Credit: J.A. Ackley

Loads of carbon fiber. Dozens of sensors. A computer plugged in. It all seems so high-tech until you take a look at their catch cans for distilled water and oil. Yes, those cans may have once served as containers for beverages.

“Not all solutions have to be the most expensive ones,” Luke notes. “In fact, most are not. The catch cans just so happen to be a good example of a simple yet effective solution.

“Beverage cans are made of very thin aluminum and thus are very light. They are also made by punching sheets, something we couldn’t easily do ourselves. Because the aluminum by itself would be prone to damage, they get wrapped in a layer of carbon fiber to increase its stiffness.

“Resourcefulness is very important. Things go wrong and designs don’t come together as expected, and being able to find simple solutions with what you have is critical.”

So don’t throw out the duct tape yet.

10. Document Everything

Last spring’s Formula SAE competition attracted a hundred teams. The University of Florida finished third. For fun, they ran in the Exhibition class at last year’s $2000 Challenge.  Photography Credit: J.A. Ackley

Formula SAE teams see a huge turnover of people over the years. As seniors graduate, freshmen enter. Organizational knowledge can disappear. UF works hard to overcome this.

“Some of our greatest assets are our alumni network, history and data from previous cars, and countless amount of testing software used for validation,” Jack says. “Even though these are unique resources and specific to our team, they show the importance of learning from your mistakes, reaching out to more knowledgeable and tenured individuals, and data collection and archiving everything.”

In addition to remaining in contact with alumni, the data they obtain on race day not only gets immediately analyzed, but also archived to a OneDrive account. The team can easily access their lessons, even ones they may have long forgotten, from more than a decade’s worth of data.