Ferrari's new carbon ring rings

[manchild]

YES!!!

http://www.pitpass.com/fes_php/pitpass_ ... t_id=29106

One of the main talking points in the Istanbul paddock, concerns the 'covers' fitted to the rear wheels of the Ferraris.

According to Ferrari, the "official" purpose of these 'covers' is to aid cooling of the brakes, however some say they could constitute a movable aerodynamic device.

For the cars to have made it through thus far, it is clear that the FIA regards the covers as 'legal', but then it wasn't that long ago that the sport's governing body expressed a similar lack of concern regarding the mass damper fitted to the Renaults.

Ferrari's Ross Brawn is (obviously) convinced they are legal, while several other leading lights in the pitlane have expressed doubts.

As was the case last year, when BAR was 'grassed up' to the FIA, and following similar events this year, mass dampers and flexi-wings, sooner or later we can expect someone to approach the sport's governing body to voice their concern.

With the World Championship now appearing to be swinging in Ferrari's favour, and with five races remaining, can we expect the FIA to act just in time to give us a real down to the wire battle in Brazil?

I hope there is at least a tiny percentage of my influnce in rising this question trough constant "ranting" on forums and blogs

[manchild]

Illegality by Dennis (3rd count)

Dennis believes the device could be in breach of the parc ferme rules, which forbid teams from replacing car parts during qualifying.

"It is not for us to judge," the McLaren chief said. "Up and down the pitlane there is some confusion over the fact, and I was told second hand that their primary purpose is to play an active role in the cooling of the brakes.

"But there is a regulation that says you are not allowed to change any aspect of the car during qualifying, so clearly when you are changing wheels you are changing an element of which is relevant to the brakes."

[RacingManiac]

there are always the possibility that BBS could cast special wheels for Ferrari for similar purpose....through some crazy thin wall casting technology or something(at least the original version, I don't know about this new one....).

May as well ask this here, whats the reason that F1 requires the car to run one piece wheel made with homogenous metallic material, as opposed to multi-piece wheel in some other series?

[DaveKillens]

I firmly believe those rings are part of the wheel. They are attached to the rotating wheel structure. Ferrari have just found an innovative way to challenge the wording and definition of "brake". For the FIA to allow it, well, that's when the politics come in.
Expect a change in the definition of "wheel" and "brake" in the FIA's regulations for next year.

[manchild]

I firmly believe those rings are part of the wheel. They are attached to the rotating wheel structure.

How can that stand when FIA regaultiosn say that rims must be made in one piece from homogenic metal material and this ring is made of carbon fibre and glued to rim? Two pieces and one of them not made of metal. That's double confrontation with FIA regulations without going into improvement of aerodynamics that makes 3rd confrontation.

[DaveKillens]

Ferrari are trying to re-define brakes and wheels to suit their own ends. If Todt says the sky is orange, Max will say it's orange..........

[Ciro Pabón]

Dave: do we really need a "new" definition of wheel? What about a new definition of "earth"? If they are "wheels" then where do we left the article 12.3 of the sporting regulations (all wheels must be made from an homogeneous material)?

Those are definitely wheel covers, used for aerodynamic purposes on a lot of less-surrealistic racing categories. Can we guess what they call them? Wheel covers. Innovation? Yes, when I was a young man. A copy from rally cars? Judge for yourself (thanx to Sarknose from grandprix.com).

Porsche, 1986


Lancia Delta S4


Peugeot Talbot Sport (by Jean Todt!). This are definitely "fan wheels".


At least, the Indycars wheels are made entirely of magnesium.

[manchild]

I'm sure they say that it is part of braking system only because they could make it out of carbon fiber. Such construction made of same material as the rest of the rim could only be achived by welding and since magnesium alloy is much heavier than carbon Ferrari continues to insist on "brake system theory" because ring made of magnesium alloy would cause loss in performance compared to conventional rim with no ring. If that wasn't so BBS would make them such rims by now.

BTW, what are specific weights of magnesium alloy used for rims and carbon fiber? It would be good to see tha ratio and loss Ferrari would have if they are forced order full-metal rims from BBS.

[Ciro Pabón]

BTW, what are specific weights of magnesium alloy used for rims and carbon fiber? It would be good to see tha ratio and loss Ferrari would have if they are forced order full-metal rims from BBS.

AZ31/AZ91 (most common wrought/casted magnesium alloys, used even by civil engineers... ): 1.85 g/cm3

Carbon fiber: 1.75 g/cm3 (I'm not totally sure, this one I had to look for).

Not a great difference (after all, magnesium is the available structural metal that has lower density). Except that magnesium has a high creep caused by high temperatures (definition of creep: the material stretches or compresses under load in a plastic manner, that is, the deformation is permanent, even if the load is constant).

Carbonization of carbon fiber occurs at 1000 degrees centigrade, while magnesium starts to creep at temperatures as low as 120 degrees centigrades.

I wonder if this is the reason, as the hot brakes probably require an special wheel alloy (if they use magnesium at all). I'd guess MZ alloy or similar, that exhibits low creep at high temperatures (actually, also at low temperatures).

After all, if magnesium ignites (it can) is hard to extinguish... you DO NOT want to use it near the exhaust, like as pedals for bikes, for example. The ignition temperature of solid magnesium (not powder, which ignites at lower "spark temperatures") is 450 degrees centigrades. It would give a new meaning to the expression "chariots of fire"...

Any other theories about why they won't make a "normal" uniform wheel with the form required?

[manchild]

Specific weight might be similar but magenesium used parts used in F1 can't be thinner than 3mm (FIA regualtions) while carbon ring they use probabbly isn't thicker than 1 or 1.5 milimeters. So magnesium version would have to be at least 3.5 to 4 mm thick which means that it would weight twice as much than carbon version.

[Ciro Pabón]

Specific weight might be similar but magenesium used parts used in F1 can't be thinner than 3mm (FIA regualtions)...

That could be the one. Magnesium has low ductility and thus high susceptibility to cracks by bending, which limits the thickness you can use in structural material. Besides, if you cast it, the minimum thickness you can reach is around 2.3 mm if you want the liquid magnesium to fill the mold properly.

Of course, there is a NEW process for casting magnesium (Thixomolding) that allows you to design parts with thickness as low as 0.8 mm. It uses magnesium pellets (like in plastic casting). This is the process used to make body parts for cameras and this is the reason most cameras are made of magnesium nowadays. Maybe FIA should put its regulations up to date?

I have an (I believe) interesting question: how do they work? They have no fins or vanes (like the Peugeot Talbot I posted). They are flat. I understand that the viscosity of air should make it stick to the carbon surface and make it flow towards the periphery of the wheel, but isn't this an inefficient way to pump air?

[dumrick]

The strangest thing is that I recall from Group C era that this covers were used to lower drag in the car but reduced brake ventilation, due to the lower area for air circulation.

[manchild]

Renault to make official protest in Monza!

http://www.paddocktalk.com/news/html/mo ... =1&catid=1

http://f1.racing-live.com/f1/en/headlin ... 5304.shtml

http://www.f1editorial.com/index.php?pa ... cleID=3004

If they've only took my "ranting" for serious at the beginning of the season

[DaveKillens]

Since this kind of wheel cover has been tried before in CART by Penske on the high speed ovals, I believe they assist in reducing drag. At Turkey, I don't think they made much of a difference, but at Monza they probably contribute a lot.
And although Ron Dennis and Flavio Britore have a lot of personal animosity, McLaren just might join the protest. They are hurting desperately for a win, and probably willing to try anything.

[manchild]

I have an (I believe) interesting question: how do they work? They have no fins or vanes (like the Peugeot Talbot I posted). They are flat. I understand that the viscosity of air should make it stick to the carbon surface and make it flow towards the periphery of the wheel, but isn't this an inefficient way to pump air?

I don't think that sum of diameters of apertures in disc is anywhere near to diameter of the rim shield, so, I believe that original brake duct (inlet) and rim shield (outlet) compared to disc apertures remind on Venturi tube (not literally but when it matter ratio of diameters). However, I think that air flow at outer side of the wheel partially creates low pressure zone which help extraction of hot air from the inside.

Anyway, I’m sure it isn’t there to improve brake cooling but only to improve aerodynamics. They made rim version, than when no one officially objected they made another one – more complex and finally in Turkey they used something that has aperture only big enough to fit air gun head and which is there obviously just for improvement of aerodynamic efficiency.