🛠 The 'Inerter' or 'J-Damper': What is it and how does it work?

FIA banned the 'Inerter' (also called 'J-Damper') in 2022... but WHAT is that? And HOW does it work? 🤔

I will give you the answers in this thread... and explain how it could have mitigated porpoising! 👀

👇Read on, and get ready to learn!👇

Car suspensions have two components:

- Spring: applies a force proportional to its deflection➡️'Transfers' the energy of the bump to the car body.
- Damper: force proportional to HOW QUICKLY it deflects➡️Dissipates such energy.

F1 cars also had the Inerter... but what is it for?

The inerter applies a force proportional to the acceleration between its two extremities.

So:
- Suspension Deflection➡️Spring Force;
- Deflection Speed➡️Damper Force;
- Deflection Acceleration➡️Inerter Force.

Invented in 2002 by a professor, F1 teams quickly adapted it to their needs!

A scheme:
When the suspension extends or compresses, the right ring moves relatively to the left ring. ↔️

Due to the thread profile, this produces a rotation of the inertial body (in 🟥 red).

This produces an inertial force proportional to the acceleration between the two rings.

How is this useful?

For any oscillation:

Acceleration: - Deflection*Frequency^2

1) The higher the frequency, the higher the acceleration vs the deflection.
2) The acceleration has OPPOSITE sign compared to the deflection.

So the Inerter 'contrasts' the spring at high frequencies!
So, the Inerter effectively makes the suspension softer at higher frequencies!

This is the 'holy grail':
- Engineers can use a stiffer suspension➡️More stable aero, more responsive car. ✅
- At higher frequency (kerbs/bumps), the suspension softens ➡️Less bouncing on unevenness! ✅

A practical example:

Vertical axis: tyre load oscillation (bad!).
Horizontal: frequency.

First, the engineer stiffens the suspension to improve the aero (solid to dashed line) ➡️ Problem: the peak increases.

Then, they employ the inerter (bold line) ➡️ The peak reduces significantly!

FIA banned the inerter in 2022, on the grounds of cost reduction. 🚫

The problem was that neither the FIA nor most teams predicted the porpoising.

The Inerter would have been the perfect weapon to fight it! (By having different stiffnesses at lower and higher frequencies.)

So that was the Inerter!🛠

Now you are one step closer to becoming an F1 engineer... or just a more tech-savvy fan! 📚

Share the thread with your friends if you enjoyed it, and follow my page to understand Formula 1 better!

https://x.com/FDataAnalysis

🛠 Multiple Rim Designs per Weekend to be Banned from 2027

Starting in 2027, the FIA will BAN the use of multiple rim designs in a single weekend to prevent a development race... but why is that an issue with a cost cap in place? 😭

Summary:
1) Teams have been allowed to design their own rims since 2026.
2) This lets them manage tyre temperatures much better, e.g. cooler during a race stint → less wear.
3) Ferrari introduced a new design in Barcelona, which played a role in HAM's win.
4) McL started experimenting with it too.
5) The FIA feared (but why?) that teams could develop one set for quali (heating tyres quickly) and one for the race (cooling them down).
6) Ban starting from 2027: only one rim design for both quali and race.

As a fan of the technical side of F1, I find these “visual” changes and innovations (wings, rims, etc.) among the most exciting aspects of the sport.

Why ban them when a cost cap is in place?

They're only making F1 less interesting for no reason...

What's YOUR opinion?

📊 US GP - QUALIFYING | QUALI ANALYSIS

No doubt Mercedes is still the aero leader: highest top speed (low drag, as shown by +4 km/h vs McL on the same PU) AND fastest through fast Turn 19 (high downforce) → unmatched efficiency!

VER lost just 10 km/h (vs ANT’s 33 km/h) between lap start and lap end → more sustainable deployment. 🔋

LEC had the highest minimum speed and stayed at full throttle longer than anyone else, but his top speed was baffling.
His 15 km/h deficit to ANT cost him 0.285s on the main straight alone, less than his gap to pole!

McL didn’t shine anywhere.

📊 US GP - RACE | RACE PACE ANALYSIS

No driver set quicker lap times than LEC!

Ferrari 1-2 in this regard! 🔥

HAM was just 0.103 s/lap slower, VER 0.140 s/lap behind.

However, ANT was within 3 tenths of LEC despite using one fewer set of tyres: he lost ~16s on pace but saved ~20s by not pitting. Terrific pace and management! 👌

RUS had NO PACE: he was slower than HAD and both McL cars, losing over EIGHT TENTHS per lap to his teammate on an equal strategy! 🤔

Rate the race 1 to 10!
7.5/10 for me.

📊 US GP - RACE | TOP SPEEDS

Alonso was one of the four drivers to reach 351 km/h during the US GP!

The Honda-powered Aston can reach high top speeds (low drag, possibly decent ICE power), but not CONSISTENTLY: deployment is unsustainable, so Aston’s AVERAGE top speed was the lowest of any team.

Ferrari started the season aiming to improve their straight-line performance. So far, they do NOT seem to have achieved that: only Aston was slower on average, with Ferrari matching Audi.

Epic drives by LEC and HAM, scoring 30 points from P4-P5 with such a low top speed!

The 6 cars with the highest top speed all had a Mercedes PU...

🛠 Cornering Performance of Each Car

I’ve analysed a season’s worth of data to show you how each car performs in ⬛️ fast and 🟩 slow corners! 🤩

Ferrari: best overall and fastest in slow corners.
Mercedes: unmatched in fast corners (highest downforce / stability?)

Cadillac was the worst overall, but Aston was even slower in fast corners: their lack of power might be forcing them to run less downforce than ideal!

Top Teams:
- Fast corners: Mercedes > Ferrari ≥ McL ≥ RBR
- Slow corners: Ferrari >> Mercedes > McL = RBR

[Data: all 2026 quali minimum corner speeds]

Mexico's slow corners should aid Ferrari 👀

Made via @JMP_software

To learn more about JMP, the program I used to process the data and to create this visualisation!

https://www.jmp.com/en/offers/breakthrough?utm_source=x&utm_medium=referral&utm_campaign=fdataanalysis_en_post&utm_audience=f1race-interest&utm_content=trial

📊 MEXICO CITY GP - PRACTICE 2 | LONG RUNS

SIX drivers within TWO TENTHS in the long runs!

Four teams potentially fighting for the win! 😵‍💫

🟥 Soft:
1) NOR;
2) HAD +0.050 s/lap;
3) RUS +0.123 s/lap;
4) VER +0.171 s/lap;
5) PIA +0.418 s/lap.

🟧 Medium:
1) LEC +0.078 s/lap vs NOR;
2) ANT +0.168.

Other teams: Gasly was as quick as Piastri and far more consistent! Racing Bulls and Bearman are looking good, too.

📊 MEXICO CITY GP - QUALIFYING | TOP SPEED

- 11 drivers hit 350 km/h on their quickest quali laps.
- 19 of them were between 349 and 352 km/h.

This is no coincidence! Maximum ERS power decreases linearly from 350 kW (475 hp) at 337 km/h to 0 kW above 355 km/h: for every km/h gained, the car must fight CUBICALLY increasing drag power with LINEARLY DECREASING power.

Cars accelerate extremely quickly up to 337 km/h, then acceleration drops as if they hit an invisible wall.
Let’s call this the “rubber band effect” (which adds to the gimmicky feel of the 2026 rules).

📊 MEXICO CITY GP - RACE | RACE PACE

Ferrari may have gifted the lead to Verstappen, but Max converted it into a win!

1) VER;
2) HAM +0.061 s/lap;
3) LEC +0.215 s/lap (his third stint, on Softs after the red flag, was much slower due to the lock-up);
4) ANT +0.310 s/lap. Youngest champion ever, once again gapping his teammate!

Some reflections on the season:
- ANT was fast and cold-blooded all season. Epic 2nd year in F1.
- Would have been a great season had RBR solved their issues earlier and Ferrari had developed a decent engine (or lobbied against the changes that hurt them).
- Mercedes DO NOT look like the vastly best car anymore. The 2027 title is at risk, but they can celebrate the 2026 one!
- McL went from WDC+WCC winners to 4th best, well short of their supplier Mercedes (and possibly hurt by the short gearing).