Lets get a few things straight here.
Personally, I have to agree with Blake - I think it was Blake - who said that Red Bull, Ferrari and Renault (and don't forget BMW, who failed to lodge the protest properly) claiming that they were protesting because it was "within the spirit of the rules" is complete and utter bull****. There's no way they can argue that what they are doing is comepletely altrusitic and that they stand nothing to gain from having the parts eclared illegal.
Of course they stand to gain from it - they never claimed otherwise. However, as far as "spirits of the rules" are concerned, there are two points to raise:
The first of which is that as of 2009, this "spirit of the rules" thing exists. Cars were radically overhauled for this season, the most radical rule-change in F1's history, not to slow cars down: But to allow easier passing. The current "spirit" is just that - if it causes additional turbulence or increases sensitivity, it's against that "spirit". And yes, we have to consider that these diffusers might increase a car's sensitivity in wake: Both because it's a bigger diffuser, with different parts of it having airflow at different velocities (the differential could cause additional turbulence), and because it needs more air to be fed in a proper fashion, thus increasing the sensitivity of their
own car to turbulence. This lines up with Timo's comments about how he lost all his grip in traffic - when up to 40%, rather than just 15%, of your downforce happens to come from a more sensitive device, that's no wonder.
This is also the reason others are struggling with the design of such diffusers: They're larger and more complex, and can't just be "strapped on" - the whole car has to be built around them in order to feed air to the appropriate holes.
We also have to consider the precedent of Brabham's BT46 Fancar: Technically, it was 100% legal, since the moveable aero was "just a fan for cooling" - which was permitted. It was obviously designed to create low pressure under the car - but also with the side-effect of cooling a little, as an excuse to make it legal. However, it was against the "spirit" of the ban on moveable aerodynamics, and so it wasn't raced anymore. The new diffusers are similar: They use the regulations around the crash-structure and related bodywork to create a new diffuser, which just happens to serve as an impact structure. It may be legal under the precise wording of the rules (and we're
not yet sure if that's true!), but they have precedents that argue in the favour of a "spirit of the rules". The old extra brake-pedals by McLaren were similar, too - legal but against the "spirit".
The second is in the way rules are interpreted: Not only the regulated diffuser-dimensions, and using the existing bodywork dimensions - we have to consider that these "extra steps" in the diffusers need feeding-channels: Holes. However, the regulations quite strictly mention "No part of the car should be visible from underneath the car" - yet these holes apparently do cause that. The 3D³ (three double-deck-diffuser teams) are arguing that these are "slits" and thus exempt - which sounds a little rubbish. Also, as Ferrari's Rory Byrne also confirms, it essentially means that ground-effects can return, in a way: By moving the rear suspensions forward, teams will be able to add additional "steps", or decks, to their diffuser and move them accordingly forwards - ground effects at a level far beyond diffusers, and nearing that of the old venturi cars.
There's also these excellent bits by Rory Byrne, which support some of my opinions on the matter. Most of the articles and interviews so far mainly state that it will or won't be banned because of various political reasons, but here's finally an in-depth article on the technical side:
Link to article
Autosport
Ferrari design consultant Rory Byrne believes the 'diffuser gang' of Brawn GP, Toyota and Williams have broken with a 15-year protocol in the way they have interpreted Formula 1's technical regulations this year.
With the FIA's International Court of Appeal due to convene on Tuesday to rule on whether double-decker diffusers used by the three teams are legal, Byrne has added his weight to arguments that they are not within the rules.
In particular, he believes that the teams' insistence that holes in the floor of the car designed to improve airflow through the diffusers should be regarded as 'slots' goes against what everybody accepted as correct for many years.
Article 3.12.5 of F1's technical regulations states: "Fully enclosed holes are permitted in the surfaces lying on the reference and step planes provided no part of the car is visible through them when viewed from directly below."
The three teams at the centre of the dispute claim that breaks in the floor of their car are not holes, but gaps between the step and reference planes of the car - so exempt from the requirement that no part of the car be visible through them.
Byrne has told Gazzetta dello Sport that he is sceptical about such a suggestion, however, saying teams had never thought like that before.
"It's a rule set at least 14-15 years ago, and that for many years everyone interpreted in the same way," said Byrne, who won many world titles for Ferrari working alongside Ross Brawn. "If you look at the Brawn car from underneath, you can see the suspension."
Speaking about his feelings on the situation, especially going against one of his former close colleagues, Byrne said: "Ross Brawn and I remain good friends, but one thing is personal relationships, another thing is the professional aspect. And I work for Ferrari."
And in the Gazetta interview:
Byrne: ''When you fully think out the principle of these diffusers then we will get real ground-effect cars once again.'' This would dramatically increase cornering speeds and problems when it comes to closely driving behind each other.
The OWG determined two aims: the 2009 cars are to produce less turbulence and they are too react less sensitively to the turblence from the car in front. The wide front wings, high rear wings etc. is what Byrne, Symonds and Lowe came up with.
But with the double decker diffuser the OWG sees their aims being jeopardised. According to Byrne, under the current regulations a conventional diffuser contributes around 15 % to the overall downforce. The South-African reckons the double-decker diffusers from Brawn GP, Toyota and Williams contribute 40 %. With that we're almost back to downforce figures from last year.
Byrne says it's only the beginning of a dangerous development. Toyota has already introduced a third level in their diffuser. ''Theoratically you can introduce as many levels as you want, or bring the diffuser ever more to the front in order to get higher downforce figures.'' Byrne estimates that the time gain of the controversial diffusers is already 1 second a lap.
The former Ferrari designer adds that it will again become more difficult to follow other cars: ''It's not so much about whether the turbulence gets increased by the diffusers at all. But those that have a diffuser like that are actually having a harder time trying to follow other cars.'' The reason behind this is that the double-decker diffuser needs an optimal approaching flow to work. ''If all the cars would be equipped with such a diffuser then overtaking will become more difficult again.''
If the Court of Appeal deem the double-decker diffuser legal then a costly 'arms race' will break out. ''We will see extreme rearsuspensions, only to allow the entry holes of the diffuser to be moved more and more forward. I can already imagine there being rearsuspension constructions similar to those seen in the '60's, with trailing arms that reach far to the front. That would create space for the diffuser channels.''
Apart from the double-decker diffusers not being within the spirit of the rules, according to the OWG they're also illegal when reading the letter of the law. ''It's a play of words: (the three teams came up with) a section divided in three parts only to apply holes in the vertical intersection between the floor and the reference plane. But the regulations don't allow fully enclosed holes in the vertical intersection. There's even talk (in the regulations) of continuous, non-subdivided planes in the diffuser.''
Byrne mentions a similar example: ''At Imola in 2001 holes were discovered in the diffuser of Williams' car. The FIA stewards objected against it and the team had to close the holes. Why is something, that used to be in force in the past, no longer in force today?
We also have to consider two different scenarios should the part be banned:
First is simple: It's illegal and results stripped, though that will be highly controversial and ever-so-slightly mad. It would promote Alonso to victory in Melbourne and Heidfeld at Sepang, and cause quite a stir.
The other is the banning as-of-now. This solution makes the most sense, and is supported by many precedents: The Renault mass-dampers, the 2003 Michelins, the Brabham fancar and many others. The 3D³ teams already have alternatives - perhaps not very competitive ones, but they won't have to stop racing.
