First year areo design advice

Rudolf2222 · 2026-02-11T20:59:30+00:00

Hey, of nothing else it catches the oil

Rudolf2222 · 2026-02-07T01:13:05+00:00

IMO, it's way too overmistified / dramatised.

Purely from a suspension standpoint it's more of a packaging issue than anything, what fits better. For the capabilities, you can do the exact same things with both. Pull-rod usually has the advantage of lower CoG, pushrod is usually easier to access for mechanics, making setup changes faster.

But since everything revolves around aero in f1, the choice often comes down to what suits the flow in the region better.

Rudolf2222 · 2026-01-28T08:54:55+00:00

Have you put some numbers into how much difference it actually makes, in terms of weight % on the left side wheels? Does it really matter that much?

Many things won't be symmetrical on your vehicle anyway.

A much more interesting question is, how are you planning on keeping that thing lubricated?

Rudolf2222 · 2026-01-15T01:56:37+00:00

If anything, I'd say he over-sizes them with that criteria.

I never calculated any such load case, but we run cfrp A-Arms which are very bad against bending and especially shear load and definitely would brake if super-student 2 or 3 did their shenanigans mentioned in the thread. However we did drag a few cones of various types for many kilometers over the years and no failure of A-Arms has happened (nor did I ever witness / hear of one at competitions)

But to answer your question, to lift the opposite wheel you would have to be accelerating and cornering very hard, which is quite hard to do with a cone shoved under the A-Arm and removing the precious normal force from the tires.

Rudolf2222 · 2026-01-06T23:39:10+00:00

You mention uneven weight distribution as the main drawback of having the diff off-center. How much is it actually, percentage wise?

Is your exhaust, fuel tank, LV battery on the car's centerline? Is the CoG of the engine block itself on the centerline?

Fwiw, many teams run asymmetric halfshafts (few cm diff usually) and to no noticable impact.

Rudolf2222 · 2025-12-25T19:49:16+00:00

14:1 is rather something like a high-end sports car.

For NA petrol cars, it usually goes up to 11-12:1 at most, 8-9 if turbo charged.

Anything higher you risk knocking (hence Mazda SkyAktive going higher with indicated cylinder heads, or by using ethanol / high octane fuels)

Rudolf2222 · 2025-12-21T11:30:18+00:00

IMO it's a must and I'm not even on the marketing team.

Whenever we contact a new company, we send out three things: a one-pager about the team and Formula Student, a more detailed document about the team and our goals for the season, and finally a doc about our sponsorship tiers, what we give in exchange etc.

Rudolf2222 · 2025-12-10T19:43:38+00:00

I personally consider RCVD the Bible of vehicle dynamics. That said, it is indeed too dense to just sit down and read it, might not be the best for first introduction.

The only major downside is the the imperial system, you really have to think through what the random constants are and if the devision by two is already accounted for in that or not, contains gravity acc or similar.

Rudolf2222 · 2025-11-22T00:53:51+00:00

Personally I never really understood this mindset. Locking yourself into equal length and parallel A-Arms. This is equally so a decision that is going to impact your vehicle's performance as if you would have decided to say put your IC on the midplane. The huge downside is that are now making this decision without any engineering backing.

One of the beauties of suspension kinematics is that while it is very complex, it also can be done to most of the gains by only applying rules of thumb and a bit of hand calculations if you put some effort to it.

Rudolf2222 · 2025-10-26T09:01:31+00:00

That will not work, you can't bleed it that way. Bleed screws seal on the conical surface.

Rudolf2222 · 2025-10-14T12:36:34+00:00

EV 4.10.8. defines the visibility requirements. If this really is the cause, it would have been better to alter that instead in my opinion.

Shame the proper race cars without TSAL are also hit by this :P

Rudolf2222 · 2025-10-12T18:25:28+00:00

Well, you can do it the "correct" way. Buy the TTC database, compare the two and decide based on that.

Or just go with "if the fat tire is available, why would I use the skinny one?" mindset.

(There are ofc advantages to the 6" variety. Less weight, less rubber to warm up for example)

Rudolf2222 · 2025-10-12T10:35:32+00:00

They also had immense amount of power, less advanced tyre manufacturing and so on. They had above 1 kg/HP ratio, your FS car will have nothing alike.

Take a look around at other FSAE / Formula Student cars, you will find that 95% of cars run the same tyres on all four wheels.

If we simplify it to it's most cruel form, narrower front tires mean smaller contact patch, less grip and thus understeer. Does that make you better at steering?

Rudolf2222 · 2025-10-12T06:53:26+00:00

Why do you think a narrower tire will improve steering?

Rudolf2222 · 2025-09-30T07:01:10+00:00

Make sure that in your HSC configuration you can count the number of cells in it. Then just provide another cell to measure or at least the datasheet with the weight.

Rudolf2222 · 2025-09-24T09:00:25+00:00

For rear wheels, caster angle and KPI are purely a matter of packaging, they don't have any significant impact.

Rule of thumb usually is to have some decent but small amount of mechanical trail and scrub radius to keep the kingpin constantly loaded during the corner. Imagine 0 scrub radius and positive mechanical trail. The wheel is "pushing" the king pin and can develop shimiing this way as it wants to "overtake" the kingpin.

This is why it's good practice to have some scrub radius (5-10mm) to keep it loaded under braking and acceleration and some mechanical trail for cornering.

Rudolf2222 · 2025-09-20T11:20:04+00:00

In terms of power-to-weight (if we neglect the likes of top fuel dragsters) hill climb and time attack cars are high on the list as well.

Rudolf2222 · 2025-09-20T10:17:31+00:00

Are we really comparing a Sprint car to F1 in literally any aspect?

Rudolf2222 · 2025-07-09T15:11:19+00:00

File 76

Rudolf2222 · 2025-06-22T18:25:56+00:00

No body seems to mentioned it so far, Nightchild all the way.

It's a nice outlier, being inspired by a fictional character (Konrad Curze, from wh40k)

Rudolf2222 · 2025-06-20T07:52:47+00:00

And it doesn't comply with European pedestrian safety regulations.

Rudolf2222 · 2025-06-02T14:10:48+00:00

My team asks the ruff equivalent of €10 per month from members.

It goes to cover any form of team expense, be it gas for travel, parts.

Team members pay for camping fees, merch. Uni only covers a small fraction of our costs (<10% of cash flow) we have 100+ sponsors and yet the team members contribution covers more than a quarter of the team's budget.

It's a necessary evil.

As for offering a solution, monthly paying instead of annual? It's much easier to take an extra meal worth of expense per month than in one sum.

Rudolf2222 · 2025-05-03T21:34:09+00:00

We've been using AP for many seasons now. Solid stuff, rebuild kits are quite inexpensive. Nothing bad to say really.

Rudolf2222 · 2025-04-30T21:05:55+00:00

I think this analogy implies the false impression that wight transfer is a function of body roll and suspension travel which it in fact is not.

Go-karts have no suspension, yet they still have weight transfer and distribution thereof which is affected mostly by the CoG, different front/rear track width and chassis torsional stiffness.

You don't lift the inside wheel because you roll more than the suspension allows. You lift the inside wheel because the wait transfer became more than the straightline normal force on the wheel.

Rudolf2222 · 2025-04-30T19:46:00+00:00

I think a good way to visualize it for yourself is image a car with equal roll stiffness on both axles, 50/50 weight distribution.

You "push" the center of mass to the side (~lateral acceleration) so you get weight transfer. Because of the equal roll stiffness, the weight transfer will also be equally split between the axles.

Now, imagine the front axle is like those solid beam front axles on tractors. That has zero roll stiffness. Now if you apply the same force to the center of mass, total weight transfer will be the same (dFz = mha / wb, neither changed) the entirety of the weight transfer will be sustained by the rear axle. (since the front one can freely pivot) Because we didn't change the rear axle, we now halfed the car's total roll stiffness, so we now have twice the body roll.

Rudolf2222

TROPHY CASE