Legality of McLaren's "Butterfly" suspension

[turbof1]

I dint understand Charlie Whiting,

Beam wing banned, Mclaren find a replacement solution for the beam wing, which i guess is legal, but then what is the point of banning the beam wing?

I believe they did it generally because they didn't want the teams blowing the beam wing. That sill stands as of now.

I generally believe the FIA wanted to get rid of some things they deemed unsafe, or some concepts they failed in the past to fully ban. Their main intention wasn't reducing downforce IMO.

[rjsa]

I dint understand Charlie Whiting,

Beam wing banned, Mclaren find a replacement solution for the beam wing, which i guess is legal, but then what is the point of banning the beam wing?

That's the whole problem with the way F1 is ruled.

Rulemakers cant outsmart designers, so each thing they impose constrains to one device it generates another strange apendix to the car, to be later dealt with again, generating another weird outcome.

They need to re-write it from scratch - the aero rules I mean.

[PhillipM]

consists of what has traditionally been done over the years and is mutually accepted to comply, and that is to not specifically design a suspension system as a means of creating downforce. Mclaren cannot sell this, in my opinion, as a secondary byproduct of their necessary rear suspension geometrical design. That is a very very tall sell.

You're not getting this are you?
Every suspension member, on every car, is directly or indirectly influencing the downforce of the car BY DESIGN.
And your beloved front pull-rod is a prime example of that, it doesn't matter if it was designed as a pull rod, the fact of the matter is geometrically, it would work better as a push rod - and again, geometrically, the front wishbones would be better on the Ferrari, etc, if they weren't so high. Both could be designed much better if they weren't trying to control and direct the front aero with the suspension members.

Given the aspect ratio and 5* max inclination, plus the blocking between the floor and the rear arms, the Mclaren rear wishbone member is probably, in itself, making no more and no less downforce than any suspension member you care to point at on any other car.
It is making a lot more drag, and it is making the rest of the car work better, but so is every suspension member on every car on the grid.
You keep banging on about them choosing the aero route first and geometry second - what's your point? - because I can show you cars and suspension members up and down the grid that are exactly the same.

[hollus]

Legal or not (that's movable aero if I have ever seen one), the thing must be draggy as hell. The cross section is equivalent to that of the rear wing. So I bet this would only be used in circuits where 100Kg of fuel is plenty, and removed where that is a limiting factor. They might just lap the entire field at Monaco and Hungary!

[iotar__]

Just to agree with your point Diesel, if they manufactured the leg as a single piece of carbon then the whole member *would* be considered structural... and the geometry would not be considered to be bodywork.

There is no rule that says you can't "over engineer" something per se. What you are not allowed are redundant suspension legs, and in engineering terms what this means is effectively each suspension arm can have a maximum of two legs. As long as those two legs conform to the other regs for suspension members, you're fine.

No, that's not how it works, there's no such thing as over-engineering as an excuse, structural or not, it's always up to interpretation.

I can't find the quote (Whiting) but the gist of it from memory was that parts of the car had their purpose described in the rules (here McLaren's suspension) anything that goes beyond that ("unnecessarily") for other, aero purposes is illegal, even if it's still part of suspension. In Lotus' case it was hydraulic cylinder, the movement itself was integral part of primary suspension function and device itself was passive (like ducts systems?).

I disagree with you. The fact of whether or not all parts of a suspension arm is structural is not open to interpretation.

The lotus suspension system was deemed illegal because it reacted to the movement of the car/the braking force.

Edit: Though that's not to say the FIA will use their sweeping hand and deem it illegal, who really understands their logical thinking process

But how is that different to McLaren? Are you saying that their suspension doesn't react to movement of the car, doesn't react to breaking? I'm not claiming that's what FIA's reaction should or will be, I'm giving example of how it happened in the past because I remembered thought process. Cases are not identical and as always there's no need for consistency .

Since teams don't talk about this angle a lot (aero purpose), only tweeter rumours (Kravitz), I can't say if anyone will be willing to apply those rules here but it can be done - working backwards from purpose to suspension. They put cylinder as part of legal suspension, with clear aero purpose, there was no other need for it just as McLaren's, no moving parts per se, only usual suspension movement - but you can't do that. When put together effect was banned under movable aero device rules.

BTW if Whiting can clarify noses why can't he clarify McLaren's suspension?

[miguelalvesreis]

Someone should open a Thread for discussion about the legalities of McL rear suspension.
It's overloading this thread with nonsense yin-yang if it's legal or not. This is supposed to be a technical thread.
The way it's supposed to work and its effects on overall efficiency of the car should be the scope of the discussion of this "butterfly-drangonfly-venetian blind" suspension!

[adrianjordan]

BTW if Whiting can clarify noses why can't he clarify McLaren's suspension?

Charlie Whiting has already ruled this legal, as have the FiA.

Please could this discussion be moved elsewhere as it's getting far beyond tedious now....

[turbof1]

Legal or not (that's movable aero if I have ever seen one), the thing must be draggy as hell. The cross section is equivalent to that of the rear wing. So I bet this would only be used in circuits where 100Kg of fuel is plenty, and removed where that is a limiting factor. They might just lap the entire field at Monaco and Hungary!

It depends on how they divert air. The engine cover is positioned relative heigh to direct air over the suspension. Also cooling air coming out of the outlets look to exit above it.

That leaves air coming from around the sidepods. They do try to leak that airflow away to minimize drag. Also a small beam wing on top of the edge of the diffuser will accelerate air, which does minimize the drag a bit.

But I think the biggest concern is the L/D. If that's atleast better then the rear wing itself, then they can just keep the suspension on all circuits and choose a smaller wing flap instead.

[acosmichippo]

I think FIA should either just leave the rules as-is and let the teams work with it however they want, OR change it so suspension members must be cylindrical with a maximum diameter. either let them innovate, or make it a spec, essentially. None of this "5 degrees" or "major axis" or "aspect ratio" leeway to worry about if they force suspension to be cylindrical.

[FW17]

I dint understand Charlie Whiting,

Beam wing banned, Mclaren find a replacement solution for the beam wing, which i guess is legal, but then what is the point of banning the beam wing?

That's the whole problem with the way F1 is ruled.

Rulemakers cant outsmart designers, so each thing they impose constrains to one device it generates another strange apendix to the car, to be later dealt with again, generating another weird outcome.

They need to re-write it from scratch - the aero rules I mean.

Personally the rules are fine, feel the enforcement is not being done in the way it is to be. In this case it is clear (blatantly) that the purpose of the devices is aero and not so much structural. It should be clarified ASAP that it is outside the spirit of the rule and needs to be dealt with a heavy hand.

Delays in such clarifications gives room for political maneuvering and that just sucks.

[bonjon1979]

Post deleted. Because I'm wrong.

[Just_a_fan]

I think FIA should either just leave the rules as-is and let the teams work with it however they want, OR change it so suspension members must be cylindrical with a maximum diameter. either let them innovate, or make it a spec, essentially. None of this "5 degrees" or "major axis" or "aspect ratio" leeway to worry about if they force suspension to be cylindrical.

The technical rules are effectively written by the teams (the Technical Working Group) not the FIA. That's why they are written in technical terms - they're written by engineers for engineers.

[Richard]

The rules define the allowed geometry for the suspension arms. McLaren suspension complies with that geometry. End of story.

It's just like the rules about brake cooling, the teams can have any shape they like as long as it fits within the defined shape in the rules.

[Coefficient]

consists of what has traditionally been done over the years and is mutually accepted to comply, and that is to not specifically design a suspension system as a means of creating downforce. Mclaren cannot sell this, in my opinion, as a secondary byproduct of their necessary rear suspension geometrical design. That is a very very tall sell.

You're not getting this are you?
Every suspension member, on every car, is directly or indirectly influencing the downforce of the car BY DESIGN.
And your beloved front pull-rod is a prime example of that, it doesn't matter if it was designed as a pull rod, the fact of the matter is geometrically, it would work better as a pull rod, geometrically, the front wishbones would be better on the Ferrari, etc, if they weren't so high. Both could be designed much better if they weren't trying to control and direct the front aero with the suspension members.

Given the aspect ratio and 5* max inclination, plus the blocking between the floor and the rear arms, the Mclaren rear wishbone member is probably, in itself, making no more and no less downforce than any suspension member you care to point at on any other car.
It is making a lot more drag, and it is making the rest of the car work better, but so is every suspension member on every car on the grid.
You keep banging on about them choosing the aero route first and geometry second - what's your point? - because I can show you cars and suspension members up and down the grid that are exactly the same.

Indeed, some teams deliberately profile their suspension elements to be "aero neutral" because that is the way they intend them to behave within the flow structure they have designed into the car. Their designs are optimised to suit aero neutral suspension elements and as such we see these aero neutral elements positioned very specifically to play their part as flow conditioners in order to achieve the desired effect i.e. clean, well-managed airflow to the downforce producing devices on the car. Have you detected what I'm getting at yet? There is no such thing as aero neutral!! Yes, as a stand alone componenet in a wind tunnel the suspension elements may be "aero neutral" but that is not how they were conceived. They were conceived as part of a package and are very intentionally shaped and positioned to help produce the optimum performance from the overall car concept.

Fundamentally there is no difference between doing this and designing the flow structure of your car to work best with a weird looking suspension element. Mclaren is legal, no question!!

[Richard]

The big issue for me is that there are more than six suspension members. The top 'A' shaped suspension arm is two suspension members (the regs state that any suspension member splitting in two counts as two arms regardless of how it started). Then there is the lower wishbone. That's six on each side - so what are the other 4 at the back counted as? It's clearly more than six suspension members.

How is this different from the wishbone on the other cars?