Mercedes W11

[SiLo]

Here are two cooling configs
https://pbs.twimg.com/media/Ei1DcNcXgAE ... name=large
via @Gianludale27

This looks like its dependent on how large the rear wing is. Trying to keep the same distance from the top of the cooling outlet to the bottom side of the rear wing.

[HungarianRacer]

Here are two cooling configs
https://pbs.twimg.com/media/Ei1DcNcXgAE ... name=large
via @Gianludale27

This looks like its dependent on how large the rear wing is. Trying to keep the same distance from the top of the cooling outlet to the bottom side of the rear wing.

Well, in Hungary they ran with the high & narrow outlets combined with their full-fat rear wings, but with extremely narrow bodywork around and behind the exhaust manifold area.... Seems to be a theme with Mercedes' cars isn't it, they start the season with borderline cooling, then they learn how to loosen up the rear packaging (for improved reliability, presumably) without sacrificing much - or any - aero performance.... With maybe the exception of the W06 (2015), I believe you'll find this to be 100% true.

[zibby43]

Merc have got their mugello fw flap again

Nice spot.

[jh199]

Would someone mind explaining to me how DAS is used to heat the tires? The way I understand it is that using DAS reduces the front toe out. Toe out increases front tire scrubbing so using DAS would decrease tire scrub. Tire scrub can be used to heat the tires. So how does reducing tire scrub result in increasing front temperature?

Sorry if this is a silly question. I just genuinely don't understand how they use it to heat the fronts.

[zibby43]

Would someone mind explaining to me how DAS is used to heat the tires? The way I understand it is that using DAS reduces the front toe out. Toe out increases front tire scrubbing so using DAS would decrease tire scrub. Tire scrub can be used to heat the tires. So how does reducing tire scrub result in increasing front temperature?

Sorry if this is a silly question. I just genuinely don't understand how they use it to heat the fronts.

Great question. Basically, the tires will heat up more evenly across the width of the tread when they're running fully upright, as opposed to the toe-out configuration.

In other words, a critical element of heating the tires is not just "peak" heating, but *uniform* heating across the width of the tread for maximum grip/consistency.

Hope I explained that clearly.

[DarthPlagueisTheVise]

Does anyone have a photo of the cooling option used on the w11s this weekend? It was looking really tight

[jh199]

Would someone mind explaining to me how DAS is used to heat the tires? The way I understand it is that using DAS reduces the front toe out. Toe out increases front tire scrubbing so using DAS would decrease tire scrub. Tire scrub can be used to heat the tires. So how does reducing tire scrub result in increasing front temperature?

Sorry if this is a silly question. I just genuinely don't understand how they use it to heat the fronts.

Great question. Basically, the tires will heat up more evenly across the width of the tread when they're running fully upright, as opposed to the toe-out configuration.

In other words, a critical element of heating the tires is not just "peak" heating, but *uniform* heating across the width of the tread for maximum grip/consistency.

Hope I explained that clearly.

Ohh ok thanks Zibby. I totally get it now

[Big Tea]

Would someone mind explaining to me how DAS is used to heat the tires? The way I understand it is that using DAS reduces the front toe out. Toe out increases front tire scrubbing so using DAS would decrease tire scrub. Tire scrub can be used to heat the tires. So how does reducing tire scrub result in increasing front temperature?

Sorry if this is a silly question. I just genuinely don't understand how they use it to heat the fronts.

If you think of it as a switch, it can be 'normally' on or 'normally ' off

[jh199]

Would someone mind explaining to me how DAS is used to heat the tires? The way I understand it is that using DAS reduces the front toe out. Toe out increases front tire scrubbing so using DAS would decrease tire scrub. Tire scrub can be used to heat the tires. So how does reducing tire scrub result in increasing front temperature?

Sorry if this is a silly question. I just genuinely don't understand how they use it to heat the fronts.

If you think of it as a switch, it can be 'normally' on or 'normally ' off

Could you elaborate a bit on this point? Are you saying "normally on" is when DAS is activated and thus, toe out is reduced? In this case there is more even surface heating across the front tires contact patch and therefore the driver has more control over front tire heating. And then "normally off" is when the front tires are in their toe out settings?

[Big Tea]

Would someone mind explaining to me how DAS is used to heat the tires? The way I understand it is that using DAS reduces the front toe out. Toe out increases front tire scrubbing so using DAS would decrease tire scrub. Tire scrub can be used to heat the tires. So how does reducing tire scrub result in increasing front temperature?

Sorry if this is a silly question. I just genuinely don't understand how they use it to heat the fronts.

If you think of it as a switch, it can be 'normally' on or 'normally ' off

Could you elaborate a bit on this point? Are you saying "normally on" is when DAS is activated and thus, toe out is reduced? In this case there is more even surface heating across the front tires contact patch and therefore the driver has more control over front tire heating. And then "normally off" is when the front tires are in their toe out settings?

It depends on the setting and if normal is 'in' or 'out' with the steering wheel.

For simplicity, lets say 'normal' is parallel. (it probably will not be but a few deg off)

Call wheel toward the driver as off and can be either parallel or toe in/out by (say) 10deg

The options are to reduce toe for less scrub and more speed when wanted, or (if that is normal) to add toe and increase friction, reduce performance when not.

So 'on' can be adding toe, or reducing toe, depending on which is 'normal'Does that make sense?

PS, I hasten to add this is just MY theory, not from Merc

[Mchamilton]

Would someone mind explaining to me how DAS is used to heat the tires? The way I understand it is that using DAS reduces the front toe out. Toe out increases front tire scrubbing so using DAS would decrease tire scrub. Tire scrub can be used to heat the tires. So how does reducing tire scrub result in increasing front temperature?

Sorry if this is a silly question. I just genuinely don't understand how they use it to heat the fronts.

You have it the wrong way round. DAS increases the toe on the front wheels, increasing scrub, and therefore tyre temp as you mentioned.

[jh199]

Yea so I understand your point Big Tea. I was just wondering why it would be used for tire heating if using DAS (pulling the wheel toward you) decreased toe out. Zibby explained that it's to prevent peak heating and obtain more uniform heating instead.

You and Mchamilton both touched on something and I believe you two may be mistaken here. You said "add toe and increase friction, reduce performance" and Mchamilton stated, "DAS increases the toe on the front wheels, increasing scrub". Yea, it does increase toe but only with reference to the 0 toe state which is not its normal state.

When the driver pulls the wheel, the toe out reduces from 3 ish degrees out to 0 ish degrees out. If you go back and watch the onboard videos, you see that the drivers have the steering wheel pushed in (i.e. toe-out) for all racing laps at speed. Therefore this should be considered the normal condition, so the normal state is 3 ish degrees out. This makes sense as well considering historically race cars are set up with a bit of toe-out. Pulling the steering wheel toward the driver (i.e. activating DAS) reduces the front toe to 0 ish degrees.

Now, I do have one new question. Watching the onboard you can see that Lewis only weaves when the tires are in their normal (toe-out) state. This makes sense to me because the angle of toe-out plus the increased steering angle from weaving will result in more front tire scrub and thus more front tire heating. He only sets the toe out to 0 degrees when he is traveling in a straight line. So calling back to Zibby43, Lewis doesn't weave or aggressively brake and accelerate when the tires are set at 0 degrees toe out so he must not be heating the tires when the tires are set to 0 degrees toe-out. So then the peak vs uniform heating argument doesnt really apply, right?

I don't mean to beat a dead horse here (DAS has like, 20 pages worth of discussion already) but I don't think my questions have been answered on this forum yet.

[Big Tea]

Yea so I understand your point Big Tea. I was just wondering why it would be used for tire heating if using DAS (pulling the wheel toward you) decreased toe out. Zibby explained that it's to prevent peak heating and obtain more uniform heating instead.

You and Mchamilton both touched on something and I believe you two may be mistaken here. You said "add toe and increase friction, reduce performance" and Mchamilton stated, "DAS increases the toe on the front wheels, increasing scrub". Yea, it does increase toe but only with reference to the 0 toe state which is not its normal state.

When the driver pulls the wheel, the toe out reduces from 3 ish degrees out to 0 ish degrees out. If you go back and watch the onboard videos, you see that the drivers have the steering wheel pushed in (i.e. toe-out) for all racing laps at speed. Therefore this should be considered the normal condition, so the normal state is 3 ish degrees out. This makes sense as well considering historically race cars are set up with a bit of toe-out. Pulling the steering wheel toward the driver (i.e. activating DAS) reduces the front toe to 0 ish degrees.

Now, I do have one new question. Watching the onboard you can see that Lewis only weaves when the tires are in their normal (toe-out) state. This makes sense to me because the angle of toe-out plus the increased steering angle from weaving will result in more front tire scrub and thus more front tire heating. He only sets the toe out to 0 degrees when he is traveling in a straight line. So calling back to Zibby43, Lewis doesn't weave or aggressively brake and accelerate when the tires are set at 0 degrees toe out so he must not be heating the tires when the tires are set to 0 degrees toe-out. So then the peak vs uniform heating argument doesnt really apply, right?

I don't mean to beat a dead horse here (DAS has like, 20 pages worth of discussion already) but I don't think my questions have been answered on this forum yet.

Does toe out not work the inner edge and toe in work the outer edge?

[dans79]

I don't mean to beat a dead horse here (DAS has like, 20 pages worth of discussion already) but I don't think my questions have been answered on this forum yet.

I think you might be looking at it a little to simply. The underlying tech allows the drivers to adjust toe on the fly. I'd be willing to bet that range of adjustment and the stop locations are all adjustable. By that I mean On one track total range of movement might be 2 degrees and on another it might be 6. On one track the stops might be at +4 and 0 degrees, at another it might be +2 and -2. Several factors are going to go into determining how DAS is configured, and it's going to be tire allocation, track, and weather dependent. Probability of a safety car is probably considered as well. You also need to keep the Ackerman in mind as well.

[jh199]

I think you might be looking at it a little to simply. The underlying tech allows the drivers to adjust toe on the fly. I'd be willing to bet that range of adjustment and the stop locations are all adjustable. By that I mean On one track total range of movement might be 2 degrees and on another it might be 6. On one track the stops might be at +4 and 0 degrees, at another it might be +2 and -2. Several factors are going to go into determining how DAS is configured, and it's going to be tire allocation, track, and weather dependent. Probability of a safety car is probably considered as well. You also need to keep the Ackerman in mind as well.

Perhaps I am underthinking it. If pulling the wheel toward you results in a negative toe angle then I totally understand the system. I was assuming the toe angle just went to 0 degrees. In this case, the inner and outer edge can be heated separately as Big Tea has mentioned.

Alright, thanks all. I'll drop this topic now