McLaren MP4-29 Mercedes

[Pup]

On the copying, I'd also add that the teams are all surely going to be maxed out on their own development, fixes, etc. through the first few races - so inserting a major project like copying this suspension is not only going to be tricky to get into the pipeline, but it will also push other things out of the way.

If this is worth copying, it will trouble the other teams on more than one level.

[beelsebob]

These arms are just two gigantic Gurney flaps that block air and create BOTH an air dam on top of the floor and a low pressure area directly behind to help the diffuser.

Honestly, I'm still puzzled how these things really work or at least are supposed to.

A possible trick I could conceive is that they try to create a Carnot diffuser with this Setup, thereby effectively increasing diffuser volume. With the given Expansion Ration of the step, you would get quite bad effciency (<0,3) of the Carnot diffuser but you might still get some DF.
Would be intereting to check in CFD if that would actually work.

They are effectively acting as the most gigantic gurney flap you have ever seen on a diffuser – but only when the car is riding high on it's suspension (i.e. only when the aero is not working well).

[Pup]

From F1.com...

This unusual solution has been garnering a lot of attention at the opening pre-season test at Jerez. McLaren have designed the MP4-29's rear suspension, in particular the toe link and the rear leg of the lower wishbone, so as to create elements which respect the 3.5:1 dimension ratio required by the regulations, but which are in effect large aero devices. At lower speeds they help improve the extraction of air from the rear diffuser, thus boosting downforce, while at higher speeds movement in the suspension components means they cut drag. The solution is considered legal by the FIA, but could lead to clarification requests from rival teams - especially as it's one that cannot be easily copied, since it would require a complete redesign of the rear suspension.

[idfx]

paraglider?

[Richard]

Forgive my ignorance and lack of sketch because I'm on a mobile ...

If we imagine this in section, we have a floor acting in combination with two flaps. To my mind that cross section doesn't look too dissimilar to the rear wing. Admittedly the blockage cause by the suspension arms is very clumsy compared to the rear wing flaps but the result is still a big L shape in section.

[Pup]

Jerez Test 1 - Day 2

This is a good example of how the apparent size of side pod undercuts is so dependent on camera angle.

[i70q7m7ghw]

Aside – I'm not sure I can see much controversy coming out of this anyway, unless they need major suspension geometry changes (which I doubt), most teams will be able to integrate this easily, there's no more car to have an influence over after this point, other than the diffuser, and it seems to have a clear, well defined influence on that.

Unless teams use a a gearbox shroud, they already need a different gearbox for the changed pickup points. That's either picking up a penalty or waiting 5 races.
And that'll probably be the easiest change.

Except that they don't pay a penalty if they adopt it during testing, and also, I did qualify this with "unless they need to change suspension geometry".

They will absolutely need to change suspension geometry. It seems the only reason McLaren have such rearward pick-up points is to make this concept work.

[henra]

They are effectively acting as the most gigantic gurney flap you have ever seen on a diffuser – but only when the car is riding high on it's suspension (i.e. only when the aero is not working well).

Agreed, that is probably the idea behind.
I'm stil not 100% convinced L/D for this solution is anywhere in a reasonable range, (With the given Expansion Ratio pressure loss would proabably be >0,7 - 0,8).
I would tend to consider it Emergency DF (Monkey seat XXL ).
Especially with the tightly fuel limited F1 this might be an exclusive solution for very slow, tight circuits.

[beelsebob]

They are effectively acting as the most gigantic gurney flap you have ever seen on a diffuser – but only when the car is riding high on it's suspension (i.e. only when the aero is not working well).

Agreed, that is probably the idea behind.
I'm stil not 100% convinced L/D for this solution is anywhere in a reasonable range, (With the given Expansion Ratio pressure loss would proabably be >0,7 - 0,8).
I would tend to consider it Emergency DF (Monkey seat XXL ).
Especially with the tightly fuel limited F1 this might be an exclusive solution for very slow, tight circuits.

Well L/D doesn't matter in slow speed corners, there, only D matters, because L is so low simply because of low speeds. The question is how much drag to the suspension members introduce when the car is hunkered down on a straight, given their profile, I suspect that there's not a huge amount of drag there.

[Avocado]

http://www.formula1.com/news/technical/2014/0/1139.html

The solution is considered legal by the FIA, but could lead to clarification requests from rival teams - especially as it's one that cannot be easily copied, since it would require a complete redesign of the rear suspension.

End of story.

[turbof1]

I think concerning drag it'll be rather ok. air coming over the engine cover will just flow over it, air around the sidepods will partly be directed between the tyres and underneath the low beam wing. The rest of that air will be leaked a the crash structure. I personally think by blocking the turbulent air coming out of the cooling outlets they actually reduce a bit of the induced drag.

[Pup]

Forgive my ignorance and lack of sketch because I'm on a mobile ...

If we imagine this in section, we have a floor acting in combination with two flaps. To my mind that cross section doesn't look too dissimilar to the rear wing. Admittedly the blockage cause by the suspension arms is very clumsy compared to the rear wing flaps but the result is still a big L shape in section.

Maybe. Someone who knows more will surely correct me, but my time here has led me to think that the important thing about wings is more what happens on the underside than on top. In that regard, this isn't much of a wing at all. I think the tricky bit is what's happening behind, and how it's pulling air from under the floor without stalling, etc. I suspect that the 'leaks' in the air dam are important.

I think what's going on in front is more about moving the air up and getting a lot of very fast, very energized air underneath the rear wing. Again, I'll probably be corrected on that, but that's the way I'm seeing it.

[turbof1]

Forgive my ignorance and lack of sketch because I'm on a mobile ...

If we imagine this in section, we have a floor acting in combination with two flaps. To my mind that cross section doesn't look too dissimilar to the rear wing. Admittedly the blockage cause by the suspension arms is very clumsy compared to the rear wing flaps but the result is still a big L shape in section.

Maybe. Someone who knows more will surely correct me, but my time here has led me to think that the important thing about wings is more what happens on the underside than on top. In that regard, this isn't much of a wing at all. I think the tricky bit is what's happening behind, and how it's pulling air from under the floor without stalling, etc. I suspect that the 'leaks' in the air dam are important.

I think what's going on in front is more about moving the air up and getting a lot of very fast, very energized air underneath the rear wing. Again, I'll probably be corrected on that, but that's the way I'm seeing it.

I personally believe the air blocked by the "mushroom suspension" will be just leaked out. It's high pressure, turbulent and slow moving air. You don't want that underneath your rear wing. I think they'll instead be using the fast flowing air the comes around the roll hoop to feed the underside of the rear wing.

The leaks at the crash structure are important. If you don't get rid of the slow moving air, the boundary layer will build up and you will get loads of drag as well as air seperation.

[Xwang]

If I've correctly understood the limits on the suspension arms geometry are no more than 3.5/1 length/height ratio and no more than 100mm height. If it is so, could the other teams only reshape their geometry arms so that to be longer and reach the limit of the diffuser? 350 mm of maximum length is not sufficient to reach such a goal with their actual rear suspension geometry?

[Just_a_fan]

From F1.com...

The solution is considered legal by the FIA, but could lead to clarification requests from rival teams - especially as it's one that cannot be easily copied, since it would require a complete redesign of the rear suspension.

I expect the first in the queue to complain will be Horner - the RB10's rear end does not look like it can easily recreate this type of device. It will be quite funny hearing the "spirit of the rules" arguments after the last few years of RB doing "spirit of the rules" things e.g. flexi wings.

The device is rather clever and is obviously central to the McLaren's design as the rear suspension pick ups are so far back on the gearbox. If it works as well as the beam wing did last year then the McLaren might have a second or more in hand at the start of the season.