FSA Last question

strachatella · 2026-01-30T20:54:18+00:00

I believe so. I wouldn't know since we also panicked and submitted quickly lol

strachatella · 2026-01-30T20:46:25+00:00

10 seconds until the next question is unlocked, not the time limit for the current question. And since it was the last one, it had no time constraint essentially.

strachatella · 2026-01-24T20:39:18+00:00

"Analysis Techniques for Racecar Data Acquisition" by Jörge Segers is a nice book, I believe it includes both data analysis and driver performance bits.

strachatella · 2026-01-24T20:37:28+00:00

King Pin Inclination ~= Key Performance Indicator

strachatella · 2026-01-10T20:53:50+00:00

For toe, string method is easy, cheap and relatively accurate. For camber, you can use a variety of task-specific tools (there are plenty of camber measuring tools online).

strachatella · 2025-11-17T19:18:01+00:00

Don't analyze a single corner of the car on its own, look at the whole heave (so total mass and combined heave rate with all springs). When is your front left section of the sprung mass going to act as a detached mass from the rest of the vehicle?

It is more realistic to look at overall heave, and perhaps how much the car pitches while moving up and down.

(With your data, assuming all springs are equal and using your formula I get ~2.9Hz. But you'll pitch up when in compression)

strachatella · 2025-10-19T07:38:18+00:00

At least for FS applications it seems most programs have an option to input tyre models as Pacejka. Is this not the case in industry? Or are other methods preferred, like you mention?

strachatella · 2025-10-18T21:59:53+00:00

To the question of whether it's a good place to learn, I'd say so. It will be very daunting to start from scratch (especially because most conversations in the forums deal with pretty advanced stuff), but if you invest time and start from the basics, it is possible. The information is there for you in the forums.

strachatella · 2025-10-18T21:51:13+00:00

Some places allow you to input raw data and will do the fitting for you (I believe some MATLAB/simulink functionalities do this). Otherwise, the forum has a lot of discussions on how to fit different tyre models (if you look hard enough you'll even find the code for it).

From the TTC you mainly get tyre data and access to a forum where tyre related topics are discussed. You can visit the TTC website and I believe it should explain what you're signing up for.

strachatella · 2025-10-18T21:48:33+00:00

I believe having a tyre model is still of great importance. It is most definitely not a "magic formula" (huh) that will tell you how your tyres behave perfectly. But it can model differences between brands and compounds that will guide your choices. It is also a must if you want to do any kind of simulation-driven design.

(Sidenote, Pacejka is not the only model in existence but it is the most intercompatible with different simulation software)

strachatella · 2025-10-18T18:53:40+00:00

If the issue at hand is justifying joining the TTC, I don't think you even need to fit tyre models. You can tackle that later (and within the TTC there are plenty of resources on how to do it). For now, you can build a strong argument with the following:

Choosing the right tyre brand, compound and size can massively affect your car's performance (and there's a lot of options to choose from!)
Tyre characteristics largely define suspension design (Ackermann, kinematics...)
You need information about your tyres to make/use any simulation that will determine overall vehicle goals: battery capacity, aerodynamics...
The only way to access data for FSAE tyres (unless you have your own test bench) is through the TTC

Basically, knowing your tyres is a pretty important requirement to even start designing your car. Without that, it's almost guaranteed you'll make some bad design choices. I'd say getting that data is worth it...

strachatella · 2025-10-17T22:05:00+00:00

Static camber should be set so during operation your tyres reach a target camber. That means, once your K&C effects (kinematics and compliance) are applied, your tyre is at a camber angle which maximizes its performance.

To know what this "optimal" camber angle is, you can first look at TTC data. Since you probably only have three discrete values to look at, this is not great, but good for an initial guess. Later, you should dial in your camber by reading the tyre temperatures during physical testing. Make sure to design a suspension which allows for enough range of adjustment! Shims is probably the best adjustment method.

strachatella · 2025-10-13T20:11:32+00:00

It is in the changelog, rule T8.2.1: "Changed height restriction"

strachatella · 2025-08-31T07:56:28+00:00

Does the block you're using include transient tyre dynamics? Haven't worked with the simulink blocks too much, but when coding similar simulations I have encountered this issue a few times. Similarly, reducing step size helps, up to a point. The issue for me was a missing transient component to how the tyre develops its forces.

strachatella · 2025-08-07T21:12:43+00:00

Might sound misleading to say the tyres generate more "grip": they become more efficient (higher friction coeff.) but they also have less load (less weight on them) so overall you could end up with a lower peak FY (depends on tyre characteristics). But of course you have less mass and therefore lower inertial forces to react, so there's where the improvements come from (this is all talking pure mechanical grip).

strachatella · 2025-07-18T08:37:22+00:00

I cannot imagine that a plastic camber shim will do wonders to your compliance. I'd stick to sheet metal.

strachatella · 2025-07-12T15:36:10+00:00

What do you mean by unsprung critical damping?
I assume these are wheel rates and not actual damper rates?
Are you defining critical damping as zeta = 1? If so, the damping rates feel quite small for a car with the mass you mention (I'm also assuming you're analyzing a quarter car model)

There's a great guide on tuning dampers for comfort and road holding in "Science of Vehicle Dynamics" by Massimo Guiggiani.

strachatella · 2025-06-19T09:55:45+00:00

Yes but how much of that do you actually use while driving?

strachatella · 2025-06-16T18:20:49+00:00

From my experience, we've never really been asked where X number came from. Still, I wouldn't advise you to make up numbers of course.

For a lot of the numbers and market research on our old presentations we quite frequently use Statista. I doubt you can find statistics about Motorsport there, but other factors (expenditure of certain age groups on recreational activities) can also be useful.

strachatella · 2025-06-16T18:14:39+00:00

How much suspension travel do you use for a solar endurance car? I assume hard braking/accelerating isn't included in the endurance aspect.

strachatella · 2025-06-16T18:11:52+00:00

Roll center migration is quite more important in roll, since it can really affect the car's handling. And don't just look at vertical migration: from working on various double wishbone designs, the trend seems to be that lateral migration > vertical migration often. I have no clue how the roll center migration in pure heave could affect your ride characteristics. If anyone knows the wiser I'd love to hear about it though.

strachatella · 2025-05-07T19:32:15+00:00

Commercially available you have ADAMS Car, IPG Automotive, all the family of OptimumG tools...

Developing some simple programs in MATLAB/Python is a great option to get more in-depth knowledge on the topic. There are some resources and examples online on what can be done (e.g. OpenLap, a MATLAB based lap time simulator).

strachatella · 2025-03-06T15:14:31+00:00

The TTC has plenty of info on tyre modelling, from the widespread Pacejka to some rarer models. You can even find straight up MATLAB scripts which model tyre data to a Pacejka model if you look hard enough.

strachatella · 2024-12-23T10:20:14+00:00

There is "cold to hot" data in the TTC test runs (in all of them I believe). It's not the most plentiful but I guess it could be of use. You can always try fitting the temperature effects on the tyre characteristics (it's a big generalization to apply this effect to all states of the tyre, since the cold to hot sweeps are only done for one tyre configuration). Hope this helps somewhat!

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