Momentum - November 2019 - 14

STUDENT
GENERATION

Coming out of the last turn on the Autocross course at Formula SAE Michigan 2019.

Sandwich-sidepod ("Roos-Gap")
with double inlet.

shape. And finally, we developed a manufacturing process that made
the new part able to resist the extreme high temperatures at the
engine outlet.
Due to this outlet shape change, we managed to reduce our fuel
consumption and were able to increase our engine torque-a win-win
situation.
We see in Europe that a lot of teams are changing their engine
concept to a single-cylinder engine because of easier packaging and less
weight and fuel consumption. As some tracks in European competitions
become narrower and slower, it gets harder to compete with a 4-cylinder
concept which has more power (which you needed in Michigan). And
without development for better efficiency, we would lose a lot of points
because on narrow tracks more power doesn't give you a big advantage.
Every year we focus on another part of the engine and try to get
nearer to the optimum and to make sure that the system is always
reliable. Too many changes in a single season are highly risky and do not
fit to our team fundamentals: complete, finish, win.
Coming to a topic that has been much discussed, the tires are
probably one of the most important parts at the car. Since there are

14 November 2019

the new 16" tires from Hoosier on the market, I suggest
almost every team had some discussions about them.
Also, at the beginning of the 2018 season, we thought
about developing our car on these tires without having
too much data of them gained from tests. After knowing
there will not be any fitting rain tires in summer 2018, we
decided to stay with the old version but make the car
able to accommodate both sets of tires. That gave us the
opportunity to switch for the Michigan competition from
18" to 16".
Designing the car for both kinds of tires almost doubled
the amount of simulations we had to do for aerodynamics
or kinematics, but in the end it was worth it. With the new
tires, we were able to use the softer compound at the
Michigan competition (the 18" tires were only available in
the hard compound), improving our results in nearly all
Events except Endurance. Also, we were able to reduce
the unsuspended mass by about 4 kg, which had a big
positive influence on the driveability of the car.
The steering forces were lowered, making our drivers
able to push themselves to the limit until the end of
the Endurance Event, and the yaw behavior has been
significantly improved. But there were not only positive
aspects coming with the tire change; it was more of a
trade-off decision. As I mentioned before, we didn't have
much tire data gained on testing; we were not able to test
the new compound on many different surfaces and could
not prevent the problem that occurred in the Endurance
Event. By pushing too much with cold tires in the first
laps, one tire started graining. As a result, our drivers had
to fight with understeering throughout the race and could
not show the full potential of the F0711-13.
All in all, under these circumstances, we could be
very happy about our 2nd place in Endurance and our
4th Overall win in a row at Formula SAE Michigan 2019,
with all of the other good-performing teams making it a
tough competition.
At this point I want to congratulate again the TU Graz
team, which finished second in probably the narrowest
result in the history of Formula Student. Also formidable
were Formule ETS Montreal, which placed 3rd place
overall, and for sure the Formula Buckeyes of Ohio State
University, which has hosted our team for years, making
our trip to the USA possible. It was a great competition
for myself and all of our team members, and I will always
remember it. Thank you for a great time!
Christian Lichtenberg, Head of Engineering for the
University of Stuttgart's Formula SAE team in 2019,
wrote this article for MOMENTUM. He is pursuing a
master's degree in mechanical engineering at the
University of Stuttgart and will serve as an advisor to
the team in the new Formula season.

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Momentum - November 2019

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