Rule Interpretation - Double deck diffusers

[Ruudje]

http://www.autosport.com/features/article.php/id/2093

new article about the diffusers.

In a perfect world, to my mind anyway, is that FIA should either impose a "flat-bottom rule", as far as there is a car to measure, or make way for full-blown grund-effects with venturis, siding skirts and the whole shabang. No fans though.
kilcoo?

Why not let the team copy the brawn diffusers and just stick with that? allowing full blown ground effect cars is far to dangerous imo.

[rationalthought]

It looks to me like BGP has made an amazing diffuser, From a technical interpretation (including the Stewards), the diffuser conforms to F1 regulations.

Spirit of rules vs. Spirit of competition

Much has been made of the spirit of the diffuser rules. The BGP diffuser looks to me like a diffuser that actually further reduces turbulence. The reduction of turbulence improves the aerodynamic efficiency of the car, and by pure coincidence, happens to improve downforce (at virtually no cost) as well.

Win win win. Better down force, better aero, less turbulence. BGP merely took a closer look at the rules and challenged their engineers to make a better diffuser.

Within the rules, there must be spirit of competition. Are rules made to make things fair? Not entirely. Why have constructors if the rules are so constrictive, each car is a complete carbon-copy (pun intended) of the other? Might as well have a One-Design. and the only variables are driver, pit crew, and strategy.

F1 is a constructor and driver competition. Brawn (and others) have studied the rulebook and found room for innovation. Let the other constructors play catch up.

I am so happy that all the ugly aero protusions are gone, and we have a nice clean look to the cars. Bravo to BGP and other for tucking the new aero technology under the back of the car where it is hardly noticed.

[Astro1]

All those saying there is no such thing as "spirit of the rules". I hope you were all there screaming that same rubbish when Ferrari got their floor and wings banned. That "spirit" sure existed then.

Here's a great article BTW.

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 ?

[timbo]

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.''

That makes sense and works in sympathy with Glock's comments on that he didn't feel that new regulations make following a car easier.

[xpensive]

My sentiments precisely, Astro1. Where did you find this gem?

[Astro1]

My sentiments precisely, Astro1. Where did you find this gem?

None other then http://www.autosport.com/news/report.php/id/74409

There is also an interesting post by V8 Fireworks on the forum there.



If the start of their main diffuser is the minimum rearward position at rear wheel line, and the 3rd deck of Toyota's diffuser starts before that, it seems logical the non DD teams may be annoyed.

1. First opening - seems to be part vertical and part horizontal? It looks like they are taking air out from under the floor, using the gap between the outside sidepod floor level and the central lower floor level of the tub, engine area etc. (??)
2. Second opening - again seems to be part vertical and part horizontal?
3. How is this continous!? Seems like a break in the line to me?
4. What's going on with these scultped bits of the floor?

[johnny99]

Does anyone think that the advantage of the diffuser is being overrated. I would bet that if the big 3 protester's had these diffuser's Brawn would still be a faster car. Didnt Rubens damage his in the last race, and it didn't seem to harm his progress too much. All these aero devices work together, and there's more to the Brawn/Toyota/Williams than the difuser.

John

[xpensive]

I think the fact that not only "Honda", but also Williams and Toyota, consistently finds themselves at a for those teams rather unusual end of the timesheets, is a very strong indication of the efficiency of this diffuser "interpretation".

[xpensive]

For Astro1:
I see no way how the FIA can declare that Toyota above legal tomorrow, when they have to consider the future interpretations of such a decision. Which would mean opening a can of worms to put it mildly.

[johnny99]

I still think there's a lot more to these cars than the diffuser, watch the way they can commit to corner entry compared to "non diffuser" cars.

John

[timbo]

I still think there's a lot more to these cars than the diffuser, watch the way they can commit to corner entry compared to "non diffuser" cars.

John

And what? is there something about corner entry that makes it irrelevant whether you have diffuser advantage or not? If anything, I'd say corner entry is the most sensitive to DF and balance of the car.
And yes of course it ain't ONLY diffuser. But diffuser is a part of the puzzle that make everything else fit.

[johnny99]

I would have thought that the front wing was the more important during initial turn, in than the diffuser, and was making a point that if the protesters had the diffuser, they will still not find the lap times there are after. I totally agree that it's not only the diffuser, and if it's found legal (which I think it will) the other teams are looking at a lot of redesign.

If I am incorrect in thinking the wing is more important, please say so. Although we use aero on our cars, I am still learning compared to so posters on here

John

[timbo]

I would have thought that the front wing was the more important during initial turn, in than the diffuser, and was making a point that if the protesters had the diffuser, they will still not find the lap times there are after. I totally agree that it's not only the diffuser, and if it's found legal (which I think it will) the other teams are looking at a lot of redesign.

I see where you coming from with this, but it is safe to say that if you consistently have too much front wing you're f*cked up big time, probably Schumi liked that (maybe earlier in his career) but that made JJLehto and Jos suffer VERY much.
Although I would agree that having efficient diffuser allows to run front wing much more aggressively.

[RacingManiac]

I think front wing is in a more advantageous position on turn in just because the way that chassis reacts, under braking the wing gets much closer to the ground and helps it create more downforce(provide you don't stall it). The key issue for handling then is to balance that with enough rear grip such that the car don't spin, since at that point your center of pressure is at the front end, your weight shifts to the front, and that the rear end will be struggling for grip if you don't have enough downforce as the car decelerates....

[Astro1]

The front wing is defiantly and important part of the "initial turn in" and the turn period, but it all has to be in proportion.

Whichever driving style the driver has, lots of front wing, or less, it has to be in proportion to what the rest of the car including the diffuser generate; which contributes a significant portion of the overall downforce.

A car that generates 20% through it's diffuser, certainly can't make up for the deficiency to a car that is generating 40% by running more front wing.

Back to the diffusers.

Artile 3.12.5 reads: "All parts lying on the reference and step planes, in addition to the transition between the two planes, must produce uniform, solid, hard, continuous, rigid (no degree of freedom in relation to the body/chassis unit), impervious surfaces under all circumstances. 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 vertical slots to allow air into the diffusers (as pictured above) that the DDD teams argue are perfectly legal as per the rules, you can't see any bodywork through them when viewed from "directly" below. This allows for unlimited floor levels to be created.

Only the lowest of these floors is mandated to be flat. The floors above the mandate and directly above can be shaped as one wishes for ground effects.

If you manage to move the rear suspension forward far enough as mentioned by Byrne, there is no real practical (there is a limit but it's wide open) limit as to how high your diffuser or whatever you want to call it would go. The downforce levels that would be generated would be enormous.

We would be braking 2004 records in no time.