Mercedes W13

[Big Tea]

It's normal to do this, a bump stop is still a spring, riding on the bump stops when the car is put into pitch or roll allows for more control as it limits how much the car can pitch and roll.

I'm taking this from GT3, GTE and LMP cars, I don't know about F1, but I think its logical to assume any car that is pitch and roll sensitive tends to run on bump stops to give maximum performance

I have to wonder though, if it is on the bump stops, how come it is still hitting the track on straight level sections?
Surely the bump stop should finalise before the plank hits the road? No matter how small a clearance 'stop' is 'stop'

Bump and roll are still sprung/damped separately in the current formula aren't they?

Does it matter? If the 'body' is stopped out on rubber it should go no lower on that (both) side as that's as low as it goes. It could still 'bump' but should not hit the floor as long as tyre flex is considered.

[clownfish]

I have to wonder though, if it is on the bump stops, how come it is still hitting the track on straight level sections?
Surely the bump stop should finalise before the plank hits the road? No matter how small a clearance 'stop' is 'stop'

Bump and roll are still sprung/damped separately in the current formula aren't they?

Does it matter? If the 'body' is stopped out on rubber it should go no lower on that (both) side as that's as low as it goes. It could still 'bump' but should not hit the floor as long as tyre flex is considered.

I think it does matter, because if you look at the suspension layout, there are (or at least used to be) a number of rockers which operate particular elements only when moving in opposite directions or in the same direction (i.e. only in roll - one side trying to extend, the other compress, or, only when both sides are being compressed).

You could therefore have a bump stop on the roll elements (limiting the maximum amount of roll), while not having one on the elements for controlling bump (is 'bump' the correct term?).

Just to be clear - this is supposition on my part, I'm really not sure if this is applicable on the current formula, so hopefully somebody who knows the system better can chime in.

[matteosc]

I have to wonder though, if it is on the bump stops, how come it is still hitting the track on straight level sections?
Surely the bump stop should finalise before the plank hits the road? No matter how small a clearance 'stop' is 'stop'

Bump and roll are still sprung/damped separately in the current formula aren't they?

Does it matter? If the 'body' is stopped out on rubber it should go no lower on that (both) side as that's as low as it goes. It could still 'bump' but should not hit the floor as long as tyre flex is considered.

Even if that is the case, rubber is definitely not infinitely stiff, quite the contrary in fact. It is just stiffer than the springs, but it will deform. And as you mentioned, there is always the tire flex, which has not "bump stops".

[Big Tea]

Bump and roll are still sprung/damped separately in the current formula aren't they?

Does it matter? If the 'body' is stopped out on rubber it should go no lower on that (both) side as that's as low as it goes. It could still 'bump' but should not hit the floor as long as tyre flex is considered.

I think it does matter, because if you look at the suspension layout, there are (or at least used to be) a number of rockers which operate particular elements only when moving in opposite directions or in the same direction (i.e. only in roll - one side trying to extend, the other compress, or, only when both sides are being compressed).

You could therefore have a bump stop on the roll elements (limiting the maximum amount of roll), while not having one on the elements for controlling bump (is 'bump' the correct term?).

Just to be clear - this is supposition on my part, I'm really not sure if this is applicable on the current formula, so hopefully somebody who knows the system better can chime in.

We are probably into interpretations of 'bump stop' now. I see it as when the two parts hit and are compressed as far as they go, that is stopped out. I am probably taking the term too literally

[PlatinumZealot]

Honestly shocked they haven’t bolted the side pods back on yet, given it should be relatively easy in free practice to see what’s going on.

With the new rear suspension that was meant to be trialled at Baku, it could work.

I know there was the photos of the lightened side pods showing the inner current configuration.

Given Aston Martin copying red bull and their car being a lot better than before, I believe side pods and how they have airflow over the rear wing/beam wing is also critical

Those old side pods wont solve the problem at all. Better you had said to copy Redbull.

[e30ernest]

Bump and roll are still sprung/damped separately in the current formula aren't they?

Does it matter? If the 'body' is stopped out on rubber it should go no lower on that (both) side as that's as low as it goes. It could still 'bump' but should not hit the floor as long as tyre flex is considered.

Even if that is the case, rubber is definitely not infinitely stiff, quite the contrary in fact. It is just stiffer than the springs, but it will deform. And as you mentioned, there is always the tire flex, which has not "bump stops".

This is my take from their Baku debrief. Granted it is simplified for regular viewers (and to prevent secrets from leaking out to their competitors), but they've expanded to what almost everyone is calling "Porpoising" into 2 different issues:

1. Actual porpoising - This was a real issue they had from the start of the season, but they claimed they mostly have this under control after Barcelona. Solving this issue uncovered a new issue which is bouncing.

2. Bouncing - this is mechanical and is actually what we were seeing in Monaco and Baku. Basically, they are running the car so low that it is hitting the road, creating this bouncing effect.

So if they are running a stiff suspension and are often riding on bumpstops, then the tires really do come into play more with them being undamped springs.

[zibby43]

I think it's wrong to say its not aero surfaces, and also admit that your aero platform has to be run lower which gives you a smaller operating window to combat porpoising. They go hand in hand surely?

The rule set is predicated on running the cars low. Low pressure area under the car, fast flowing air front to back, Venturi tunnels, etc.

[zibby43]

You can see the ride height in many of the photos here:

https://www.astonmartinf1.com/en-GB/new ... gp-weekend

I suspect the bouncing is more to do with the aero concept as AM had significant porpoising before the Barcelona changes. I don't think their suspension has changed.

Andrew Shovlin seems to disagree with the notion that the bodywork has anything to do with the porpoising.

"The ride issues are unlikely to be due to the shape of the bodywork of the car, as some of it is definitely mechanical.

"If you have a car that's generating downforce, closer to the road, so its peak is lower, then you've got less room to play with. And you have to inherently run it stiffer.

"There's a lot of areas that we're looking at. So I think it's probably simplifying it to say: do we suddenly make a car that looks radically different, and head off on a different direction?

I think aero surfaces are a red herring.

Based on how the season has unfolded thus far, I highly doubt Shovlin and his design team can truly pinpoint the source of said porpoising. So I wouldn’t rule out sidepods/aero surfaces.

That's a straw man, no offense. And they're acutely aware of the issues, it's how to best solve them given limited real-world testing, countless variables, etc.

There isn't some Perry Mason moment the team is waiting on.

[zibby43]

Does it matter? If the 'body' is stopped out on rubber it should go no lower on that (both) side as that's as low as it goes. It could still 'bump' but should not hit the floor as long as tyre flex is considered.

Even if that is the case, rubber is definitely not infinitely stiff, quite the contrary in fact. It is just stiffer than the springs, but it will deform. And as you mentioned, there is always the tire flex, which has not "bump stops".

This is my take from their Baku debrief. Granted it is simplified for regular viewers (and to prevent secrets from leaking out to their competitors), but they've expanded to what almost everyone is calling "Porpoising" into 2 different issues:

1. Actual porpoising - This was a real issue they had from the start of the season, but they claimed they mostly have this under control after Barcelona. Solving this issue uncovered a new issue which is bouncing.

2. Bouncing - this is mechanical and is actually what we were seeing in Monaco and Baku. Basically, they are running the car so low that it is hitting the road, creating this bouncing effect.

So if they are running a stiff suspension and are often riding on bumpstops, then the tires really do come into play more with them being undamped springs.

Bingo. So many people are conflating the pre-Barcelona aero-induced porpoising with the literal ground-scraping that is occuring now as a result of running the car slammed (resulting in skimming the bumps of temporary circuits).

It's just like F1 to introduce a rule set that requires cars to be run low, and instead of utilizing permanent circuits with smooth tarmac, they load up the calendar with street circuits lol.

[Shakeman]

I disagree, the car was obviously porpoising in Baku. A combination of rough road and high velocity caused the porpoising to return with bells on. You can see it's porpoising because of its cyclic behaviour.

The big difference between Merc and other cars' porpoising is that they appear to be generating way too much downforce for the capability of the suspension to support the car and it is being slammed into the track not just hitting bumps, although it is also doing that too.

There are many modes to the porpoising phenomenon as Kyle Engineer's video on the subject explains, many other (slower) cars have not experienced porpoising to the levels Merc is because they simply are not generating the level of downforce the Merc is. Ricciardo never experienced it until Baku because his floor hasn't created porpoising until exposed to the high speed of the start/finish straight.

Much has been said about Red Bull's suspension layout, I don't think that's why they're better, I think Newey is being less 'greedy' with underfloor downforce. I think their floor is much less peaky in downforce generation and operates over a much wider ride height range.

I have no proof of any of the above of course but that's what it looks like from all the footage I've seen this year.

[mkay]

I think it's wrong to say its not aero surfaces, and also admit that your aero platform has to be run lower which gives you a smaller operating window to combat porpoising. They go hand in hand surely?

The rule set is predicated on running the cars low. Low pressure area under the car, fast flowing air front to back, Venturi tunnels, etc.

Then how come RB generates more downforce than Mercedes by running a greater ride height? They've gotten a more efficient floor? Better downforce generation coming from the body?

[matteosc]

Does it matter? If the 'body' is stopped out on rubber it should go no lower on that (both) side as that's as low as it goes. It could still 'bump' but should not hit the floor as long as tyre flex is considered.

Even if that is the case, rubber is definitely not infinitely stiff, quite the contrary in fact. It is just stiffer than the springs, but it will deform. And as you mentioned, there is always the tire flex, which has not "bump stops".

This is my take from their Baku debrief. Granted it is simplified for regular viewers (and to prevent secrets from leaking out to their competitors), but they've expanded to what almost everyone is calling "Porpoising" into 2 different issues:

1. Actual porpoising - This was a real issue they had from the start of the season, but they claimed they mostly have this under control after Barcelona. Solving this issue uncovered a new issue which is bouncing.

2. Bouncing - this is mechanical and is actually what we were seeing in Monaco and Baku. Basically, they are running the car so low that it is hitting the road, creating this bouncing effect.

So if they are running a stiff suspension and are often riding on bumpstops, then the tires really do come into play more with them being undamped springs.

That is what they say very clearly and explicitly and it is most likely what is happening. They solved the porpoising, but now they have issues with bouncing/bottoming.
Not sure how they plan to fix it or why the car concept is to run it so low that it touches the ground.

[matteosc]

I disagree, the car was obviously porpoising in Baku. A combination of rough road and high velocity caused the porpoising to return with bells on. You can see it's porpoising because of its cyclic behaviour.

The big difference between Merc and other cars' porpoising is that they appear to be generating way too much downforce for the capability of the suspension to support the car and it is being slammed into the track not just hitting bumps, although it is also doing that too.

There are many modes to the porpoising phenomenon as Kyle Engineer's video on the subject explains, many other (slower) cars have not experienced porpoising to the levels Merc is because they simply are not generating the level of downforce the Merc is. Ricciardo never experienced it until Baku because his floor hasn't created porpoising until exposed to the high speed of the start/finish straight.

Much has been said about Red Bull's suspension layout, I don't think that's why they're better, I think Newey is being less 'greedy' with underfloor downforce. I think their floor is much less peaky in downforce generation and operates over a much wider ride height range.

I have no proof of any of the above of course but that's what it looks like from all the footage I've seen this year.

I think that the issue we saw in Baku is clearly aerodynamic related (like almost everything else in a F1 car), but that does not mean that it is actual porpoising. I agree with your statement about the downforce and I believe that Mercedes went for maximum downforce, obtaining an "aeromap" extremely peaky. I also agree with the Red Bull having a smoother downforce characteristic. That said I think that Mercedes used to bounce because of the famous stall in the floor (porpoising), while now it bounces because the floor hit the ground without stalling (bouncing/bottoming).
Externally the two phenomena would look extremely similar, but I think they have different origins, as they publicly stated.

[Evo2racer]

Maybe they should just revert back to the original A car they debuted when pre-season started in Barcelona… when their fancy side pods were still of the conventional design like the other teams.

This solution is too slow from what MB AMG said so not an option

[matteosc]

Maybe they should just revert back to the original A car they debuted when pre-season started in Barcelona… when their fancy side pods were still of the conventional design like the other teams.

This solution is too slow from what MB AMG said so not an option

Also, it has mostly to do with the floor design. The sidepodes are affecting the managing of the front wheels wake and are definitely important, but they are not the only problem (and they ay be not a problem at all...).