McLaren MP4-26 Mercedes

[gibells]

I believe the exhaust is cut to give a similar effect to Torro rosso. Wide energy distribution... OR if not, a side stream to the diffuser edges.

I think thats a great explanation and more feasible that an FEE. I can see FEE not working out completely with heat dissipation through the sidepods. I think this is a good compromise and on this occasion good enough to get Renault to do the hard graft of tuning up.

[Just_a_fan]

It should be fairly obvious. You get an airflow coming in at a different angle across your surface, it moves into an enclosed area, you get pressure points, air comes off leading edges, faster air moves in, that air interacts...... It's a complex proposition for any wind tunnel or CFD simulation. If McLaren haven't accounted for everything here it could get very complicated.

We'll see, that's all I'll say.

And you think the effect of a crosswinf on the McLaren will be any worse than on cars running shark fins? All F1 cars struggle with crosswinds because they're all designed and optimised in "head-on" conditions.

So far we have had a report of Button saying the windy conditions made testing tricky. If he was asked to run a certain lap time and he had variable winds on the track e.g. head wind on one lap, a cross wind on the next, then he'll stuggle to set a consistent laptime no matter what he's driving.

If the McLaren drivers start saying things like "there's a funny shimmy from the car in crosswinds" then maybe you're on to something. As you say - we'll have to wait and see.

[segedunum]

And you think the effect of a crosswinf on the McLaren will be any worse than on cars running shark fins?

Yes. What McLaren have with the shallow parts of their sidepods is an area where air can be compressed, slowed and where multiple changes in direction can take place. You need to make sure you completely understand what happens there. You also have to remember that McLaren are counting on these shallow sidepods to create a clean and uninterrupted flow of air to the back of the car. They can't afford it to be disrupted in any way otherwise they will lose downforce.

In short, you have a lot of variables that are ripe to create unpredictable instability several steps down the line. If McLaren have been able to account for these and it works well then great but it's something we've not seen on cars in the past, probably for good reason. These sidepods are probably going to change dramatically in shape though as McLaren understand the whole concept in practice.

[segedunum]

Sometimes i wonder why teams don't learn their lesson.
Copy the damn redbull, fiber for fiber, you can't lose!!
Stepney gate is proof enough of the copying philosophy. We had a championship car.

Steady on. I think Honda and now Mercedes have tried that and it hasn't exactly worked out great.

I expect we'll see a lot of shape changes to these sidepods and it will be a massive area of development for McLaren as they get a handle on it. Even if they have been caught off-guard in testing with something there's a lot they can potentially do.

[Just_a_fan]

Seg, I agree that the sidepods will probably change as the year progresses. I do wonder if they might actually be able to run the car later in the year without the upstand section of the sidepods - it will need smaller rads though so might be tricky. But imagine the potential gains if they can do so. It might be a development of the concept for next year though much like RBR have managed to shrink their sidepods over the three years their car has been developed.

[myurr]

But imagine the potential gains if they can do so.

Really depends on how the turbulence from the front wheels interacts with the design. If the majority of the turbulent air is being pushed outwards or is finding it's way into the side pod then what may currently be a controlled situation could result in that turbulent air being pulled round onto the beam wing / rear wing which would cause a loss of downforce.

You also have to consider the side impact regulations - currently I believe McLaren will have their side impact structures within the upper part of that side pod.

[Richard]

Yes. What McLaren have with the shallow parts of their sidepods is an area where air can be compressed, slowed and where multiple changes in direction can take place. You need to make sure you completely understand what happens there. You also have to remember that McLaren are counting on these shallow sidepods to create a clean and uninterrupted flow of air to the back of the car. They can't afford it to be disrupted in any way otherwise they will lose downforce.

Given the theory about Renault, I wonder what would happen if McL plated over the trough to create a tunnel? Shields the airflow from turbulence, and means you can direct it where you want at the back.

Of course that would only work if the benefits were greater than the penalty of the increased frontal area, the change aero over the outside of a larger sidepod ... etc...

[Remote_Access]

And you think the effect of a crosswinf on the McLaren will be any worse than on cars running shark fins?

Yes. What McLaren have with the shallow parts of their sidepods is an area where air can be compressed, slowed and where multiple changes in direction can take place. You need to make sure you completely understand what happens there. You also have to remember that McLaren are counting on these shallow sidepods to create a clean and uninterrupted flow of air to the back of the car. They can't afford it to be disrupted in any way otherwise they will lose downforce.

This, and some comments you made in the Renault thread, indicate you may misunderstand basic fluid dynamics. I am only a layman and can tell you that in subsonic conditions you won't find the air being 'compressed' anywhere.

The fact that oncoming air can take the shortest route to the rear of the car is the exact advantage of the system. Other cars are pursuing alternatives, such as highly sculpted sidepods or deep undercut. And far from 'slowing the air down', the system apparently works to minimise any changes in air velocity by allowing the flow to pass unimpeded. Why should this be difficult for them to understand?

Your theory that in yaw these top cuts are somehow deeply prone to losing all effect is so far completely unfounded. The crux of your point is that any unnecessary surface area is badness - were you born after the 2008 season?

In short, you have a lot of variables that are ripe to create unpredictable instability several steps down the line. If McLaren have been able to account for these and it works well then great but it's something we've not seen on cars in the past, probably for good reason. These sidepods are probably going to change dramatically in shape though as McLaren understand the whole concept in practice.

Okay so two points:

1. Relatively clean air passing by as unimpeded as possible is somehow less stable than air that has to work around the tub, sidepods and several tyres before doing the bulk of its useful work? I guess that's "obvious" to you, but to the rest of us it is a non sequiter.

2. Thank you for giving a ripe example of your overwhelming bias with the "probably for good reason" comment. Such comments have not been made about Renault's exhaust, which you admire (and why not), nor Red Bull's spectacular innovations over the last few years that have set the benchmark for all to follow.

You are quickly becoming the joke of this forum.

[Richard]

Here's a pic of the MP4-22 (2007) car with fins on the side pods. The 23 car had similar fins and that won the WDC in 08 ...

[myurr]

Here's a pic of the MP4-22 (2007) car with fins on the side pods. The 23 car had similar fins and that won the WDC in 08 ...

No no no.... but compression points... distruption... interruptions... YAW!!!!

[Just_a_fan]

But imagine the potential gains if they can do so.

Really depends on how the turbulence from the front wheels interacts with the design. If the majority of the turbulent air is being pushed outwards or is finding it's way into the side pod then what may currently be a controlled situation could result in that turbulent air being pulled round onto the beam wing / rear wing which would cause a loss of downforce.

I doubt the beam wing gets totally clean air anyway. The air hitting is almost certainly turbulent to some degree.

You also have to consider the side impact regulations - currently I believe McLaren will have their side impact structures within the upper part of that side pod.

L-shaped structures? May be but until we see the thing 'naked' we won't know for sure.

[Richard]

No no no.... but compression points... distruption... interruptions... YAW!!!!

OK, my post was a bit tongue in cheek, but it was does raise a question. In what way is the trough in the 26 different to the fin on the 22 & 23?

Both have air flowing along a U shaped trough that is subject to cross winds over the top. I imagine there is a difference in the creating that channel with a knife on the 22 rather bludgeoning with the upstand of the sidepod this year.

I was really trying to focus on yaw and cross winds.

[imightbewrong]

Scarbs: McLaren Roll Hoop and Cooling Arrangement

He seems to have missed the split side pod intake though..

[mclaren777]

Someone needs to take a FLIR camera to the next test because this rampant speculation is getting out of hand.

[scarbs]

Scarbs: McLaren Roll Hoop and Cooling Arrangement

He seems to have missed the split side pod intake though..

Those little inlets are for cooling the electronics and hydraulics within the sidepods. Most teams have inlets positioned just inside the main sidepod inlet.