Mercedes W15

[Vanja #66]

Honestly, there's no evidence whatsoever that Mercedes troubles are related to suspension. None at all.

Let's make a quick summary. With W13 they wanted to run low, but were stunned by outrageous porpoising, forcing them to often run high, maybe evene higher than what suspension was designed for - yet all the tyre trouble they had was not being able to heat them up to optimum window in Q sessions, and more often it was striking Hamilton who was also running setup experiments all year.

With W14 they made a big mistake in choosing to switch their concpet to run higher and were not really able to go too low due to the range suspension was designed for (at least this is what I noticed and concluded). They had even less tyre heat-up issues and overall seemed more consistent with their race pace compared to RB over the season.

With W15 they redid everything, including suspension. Two races, no tyre issues at all basically. No apparent issues with ride quality in bumpy Bahrain, just overall lack of aero load from the floor. In Jeddah not too many issues with ride quality (even though they went for really low ride height) and was just a case of even more severe lack of overall load with smaller wing level than others and then further enhanced by the issue of rear end instability is high speed corners (and I strongly suspect in high speed chicanes).

Just a brief example at how actual suspension issues look like. With launch SF23, Ferrari had lots of trouble unlocking their potential. It was only race 4 in Baku when they seemed to have figured out how to setup their car to optimise their floor performance. By then it was a race with horrid degradation, another race where they couldn't switch on Hard tyres and Australia where they looked better, but the race itself was completely weird. 0 consistency basically. And it kept happening even with Evo spec in Barcelona and in all races until the end of the season they either had too much deg on Softs and Mediums or they had issues with race pace on Hards. They had loads of issues with aero balance all year, but they still couldn't work all the tyre compounds in optimal range the whole year. With SF24 they had to redo everything and they still have some minor niggles with Hards in the race, at least in Jeddah.

Contrary to all that, Merc has a specific floor performance issue - unpredictable bouncing and hifh-speed rear end instability. Two fully aero-related issues and completely unsolvable with suspension setup changes. And yes, at this point if you are running tyres well, it typically means you'd ruin that by going too stiff - so you need to solve bouncing with aero design of the floor, period.

[Y-250.A]

Honestly, there's no evidence whatsoever that Mercedes troubles are related to suspension. None at all.

I agree , as AMR shared the same suspension its not the issue

I think its more the floor that has the main weakness or at least behind the most of the problem ( as shovlin mentioned that the ayro team is working so hard to solve the problem )

[K1Plus]

Honestly, there's no evidence whatsoever that Mercedes troubles are related to suspension. None at all.

Let's make a quick summary. With W13 they wanted to run low, but were stunned by outrageous porpoising, forcing them to often run high, maybe evene higher than what suspension was designed for - yet all the tyre trouble they had was not being able to heat them up to optimum window in Q sessions, and more often it was striking Hamilton who was also running setup experiments all year.

With W14 they made a big mistake in choosing to switch their concpet to run higher and were not really able to go too low due to the range suspension was designed for (at least this is what I noticed and concluded). They had even less tyre heat-up issues and overall seemed more consistent with their race pace compared to RB over the season.

With W15 they redid everything, including suspension. Two races, no tyre issues at all basically. No apparent issues with ride quality in bumpy Bahrain, just overall lack of aero load from the floor. In Jeddah not too many issues with ride quality (even though they went for really low ride height) and was just a case of even more severe lack of overall load with smaller wing level than others and then further enhanced by the issue of rear end instability is high speed corners (and I strongly suspect in high speed chicanes).

Just a brief example at how actual suspension issues look like. With launch SF23, Ferrari had lots of trouble unlocking their potential. It was only race 4 in Baku when they seemed to have figured out how to setup their car to optimise their floor performance. By then it was a race with horrid degradation, another race where they couldn't switch on Hard tyres and Australia where they looked better, but the race itself was completely weird. 0 consistency basically. And it kept happening even with Evo spec in Barcelona and in all races until the end of the season they either had too much deg on Softs and Mediums or they had issues with race pace on Hards. They had loads of issues with aero balance all year, but they still couldn't work all the tyre compounds in optimal range the whole year. With SF24 they had to redo everything and they still have some minor niggles with Hards in the race, at least in Jeddah.

Contrary to all that, Merc has a specific floor performance issue - unpredictable bouncing and hifh-speed rear end instability. Two fully aero-related issues and completely unsolvable with suspension setup changes. And yes, at this point if you are running tyres well, it typically means you'd ruin that by going too stiff - so you need to solve bouncing with aero design of the floor, period.

Basically what you're saying is if they can't figure out how to design a proper floor, they're cooked and won't ever be near Ferrari, let alone Red Bull.

[ing.]

Hmm possible they aren't mimmicking the floor stiffness properly throughout CFD to Windtunnel, to race car... is it really that sensitive though?

That might have been an issue in early 2022 and especially with big exposed zeropod-floor, but I don't think floor stiffness is an issue since W14, and especially W14B. I still believe they had this issue with floor stiffness in 2022 and also Ferrari in early 2023. It's not coincidence stays have evolved from cables (tension only, so floors were free to flap around a bit) to bars (no flapping anywhere).

The focus on the floor stays at the rear would seem to highlight the dependence of DF and bouncing on rear ride height and, critically, the floor sealing from proximity to the ground (including flexing) of the floor edge.

I expect that for the purpose of formulating a dynamic model, the teams use WD testing to determine aerodynamic derivatives to spike out the dependence of certain dynamic characteristics of the car on its aerodynamic behaviour. And I would think that they test the various deformed (flexed) floor edges to do this.

[Hutchie.91]

The focus on the floor stays at the rear would seem to highlight the dependence of DF and bouncing on rear ride height and, critically, the floor sealing from proximity to the ground (including flexing) of the floor edge.

Why are people still talking about floor sealing? We don't want to seal the floor and it isn't something we even try to achieve, in fact it's the opposite. We're not in the 70s anymore.

We are wanting to extract lossy flow out of the floor to protect certain vortex structures and help mass flow rate through the floor and as well as inject better quality CpT back into the diffuser and clean up flow around the flank/ODW, otherwise what would be the point in the edge wings and crazy flank geometry?

[PlatinumZealot]

Isn't Aston using the same suspension at the back as Mercedes?

It's not literally the same. It's like a BMW M3 and 3 series. Same arms, possibly the same uprights, the same hard points, the internal structural hard points are the likely the same. But the M3 was fitted with different dambers, thicker rods bushings etc.
Meaning that Aston Martin did not have to do any structural calculations or motion calculations to even start manufacturing a suspension/gearbox combo... they received a package. A package as with any F1 package - even the engine is extremely tunable within certain boundaries. These suspension have hundreds of thousands of different ways to set them up. The problem is.. where is the sweet spot with the suspension in combination with the correct aerodynamic behaviour.

I'm not good at wording things concisely, but I hope you see what I mean. The physical suspension is just the tip of the iceberg.

[PlatinumZealot]

Honestly, there's no evidence whatsoever that Mercedes troubles are related to suspension. None at all.

Logically, this is too bold a claim... I do not disagree with the nuance of what you are saying... meaning the physical suspension of the car does not need to be redesigned. But the performance of these floors are inextricably linked to ride height - so suspension MUST be involved. They cannot ignore what the suspension is doing here. Even if the suspension is doing the same motions as the RedBull one, they still have to take note of it. If you get what I mean.

[Sevach]

Honestly, there's no evidence whatsoever that Mercedes troubles are related to suspension. None at all.

Logically, this is too bold a claim... I do not disagree with the nuance of what you are saying... meaning the physical suspension of the car does not need to be redesigned. But the performance of these floors are inextricably linked to ride height - so suspension MUST be involved. They cannot ignore what the suspension is doing here. Even if the suspension is doing the same motions as the RedBull one, they still have to take note of it. If you get what I mean.

This car doesn't porpoise like crazy on the straights anymore(over 300 kph), it bounces under specific conditions on high speed corners(around 250 KPH).
Honestly it's unclear to me wether this is because the car still rides too low and is simply htting the ground too much and too hard when downforce and yaw combine or an aero phenomenom.

Shovlin did say that it couldn't be easily cured with a different bar or spring.
And in the race with higher ride heights due to slower speeds they don't bounce, but are still way off.

[izzy]

Honestly, there's no evidence whatsoever that Mercedes troubles are related to suspension. None at all.

Logically, this is too bold a claim... I do not disagree with the nuance of what you are saying... meaning the physical suspension of the car does not need to be redesigned. But the performance of these floors are inextricably linked to ride height - so suspension MUST be involved. They cannot ignore what the suspension is doing here. Even if the suspension is doing the same motions as the RedBull one, they still have to take note of it. If you get what I mean.

This car doesn't porpoise like crazy on the straights anymore(over 300 kph), it bounces under specific conditions on high speed corners(around 250 KPH).
Honestly it's unclear to me wether this is because the car still rides too low and is simply htting the ground too much and too hard when downforce and yaw combine or an aero phenomenom.

Shovlin did say that it couldn't be easily cured with a different bar or spring.
And in the race with higher ride heights due to slower speeds they don't bounce, but are still way off.

Presumably they've had to raise the ride height to stop the throats choking and that's cost them downforce. So Vanja was saying the tunnels might be too shallow, which looks great until they get to a real track and its bumps and dynamics. Then, as far as I understand it, they try to fix it with stiffer suspension and that makes it skip and unpredictable.

But how they can't use stops and the floor glides to limit the compression of the flow in the throat is something I don't understand. They have real F1 aeros working on it so it does seem weird, from the outside.

[PlatinumZealot]

Smooth road or low to medium speed turns ... No problems.
Bumpy road or high speed thurns.. Problems...

Vibration of floor platform >>> some unidentified unsteady flow structures under the floor that Mercedes don't understand how to prevent/mitigate/cancel out/ control? >> loss of downforce...

The suspension could lie somehwhere in this hypothetical.. Or not.. But at the end of the day the suspension has to be tuned to whatever floor setting or design solution they come up with.

[venkyhere]

IMHO, Mercedes have gone from :

Issue =
Ride-height sensitivity and susceptibility to porpoising/bouncing (W13)
TO
Issue =
Lateral aero-load gradient and center-of-pressure changes in high speed turns due to not-very-evolved floor design (W15) that can't deal with the differences across the left and right floor venturis when the car has yaw at high speed.

W13 issue was solved by suspension redesign and floor modifications.

Whether the new W15 issue is "fix-something-create-bug-elsewhere" OR whether this is a "completely new operational zone (ride-height, venturi size, center of pressure) that was never part of the aero-map at any point in the past 3 yrs and hence the unfamiliarity on how to deal with those specific set of simulation v/s reality differences" is key to solving this, I guess.

[Vanja #66]

The focus on the floor stays at the rear would seem to highlight the dependence of DF and bouncing on rear ride height and, critically, the floor sealing from proximity to the ground (including flexing) of the floor edge.

I expect that for the purpose of formulating a dynamic model, the teams use WD testing to determine aerodynamic derivatives to spike out the dependence of certain dynamic characteristics of the car on its aerodynamic behaviour. And I would think that they test the various deformed (flexed) floor edges to do this.

Yes, rear corner edges deforming under load and providing something close to mechanical floor sealing and just being lower to the ground resulted in an unexpected rear downforce increase. And just as unexpectedly it disappeared and left the driver clueless about sudden rear grip. It can't be controlled and used as an advantage within this rule set, so better to cancel it out completely.

As for WT testing, that would be something teams wouldn't reveal I'm afraid But it sounds completely sensible, doable and desirable. However, I'm not quite certain on deformed edges, because they now really want to have their shape under control because it also has crucial influence of keeping dirty air away from diffuser.

Basically what you're saying is if they can't figure out how to design a proper floor, they're cooked and won't ever be near Ferrari, let alone Red Bull.

No, I think they will catch up this year and they will of course hope to start a lot closer or on par in 25. They already confirmed they will carry out significant tests in Australia, maybe they will finally accept they need to focus on useful downforce and not peak downforce. Or maybe they just can't get to the same downforce level with fully compliant floor in all cases of operation and knowingly choose to design it like this, but I don't think this is the case. It's a very specific situation of high-speed rear end instability and it reminds a lot of Ferrari's troubles last year and that specific floor performance issue was only related to aerodynamic design, in their own words.

Logically, this is too bold a claim... I do not disagree with the nuance of what you are saying... meaning the physical suspension of the car does not need to be redesigned. But the performance of these floors are inextricably linked to ride height - so suspension MUST be involved. They cannot ignore what the suspension is doing here. Even if the suspension is doing the same motions as the RedBull one, they still have to take note of it. If you get what I mean.

I understand what you are saying as well, but in my view they have reached the point where suspension is working is at should and they shouldn't try to make it stiffer or change other settings trying to gain aero benefits. Besides, like I said above, this reminds a lot of Ferrari's rear-end issues last year which where confirmed to be related to aero design only.

[ing.]

The focus on the floor stays at the rear would seem to highlight the dependence of DF and bouncing on rear ride height and, critically, the floor sealing from proximity to the ground (including flexing) of the floor edge.

I expect that for the purpose of formulating a dynamic model, the teams use WD testing to determine aerodynamic derivatives to spike out the dependence of certain dynamic characteristics of the car on its aerodynamic behaviour. And I would think that they test the various deformed (flexed) floor edges to do this.

Yes, rear corner edges deforming under load and providing something close to mechanical floor sealing and just being lower to the ground resulted in an unexpected rear downforce increase. And just as unexpectedly it disappeared and left the driver clueless about sudden rear grip. It can't be controlled and used as an advantage within this rule set, so better to cancel it out completely.

As for WT testing, that would be something teams wouldn't reveal I'm afraid But it sounds completely sensible, doable and desirable. However, I'm not quite certain on deformed edges, because they now really want to have their shape under control because it also has crucial influence of keeping dirty air away from diffuser.

True - I expect teams will know by now how to design an adequately rigid for edge and not bother to spend WT time testing deformed edges. I also think, though, that they may have done some testing in the past on deformed edges to better understand the sensitivity of DF and other aero before related to this.

[Venturiation]

[maygun]

https://pbs.twimg.com/media/GJDUwKRXgAE ... name=large

This sounds a bit made up, I don't think any sane team would bring a major floor update to the first race. I also don't remember any mention of a floor update in the first race or in Saudi.