solid wheels

[supertouring]

I also do not think Carbon disks were allowed in the BTCC? I am sure they used Carbon pads, but the disks could not.

Extract from the "excellent" supertouring website:

Brakes: The limitations on brakes are few, and mainly concern the use of composite materials within the disk and calliper mechanism. All disks must be made of a ferrous material but there is no restriction on their size other than the limits imposed by the size of the wheel within which they must fit. The callipers must be made from aluminium materials, but the number of callipers per wheel is not restricted neither is the number of pads per calliper.

[gttouring]

Lemee see- Carbon discs...supertouring 'Brake discs can be made of a cast iron, carbon-fibre, or silcone carbide material..." page 91 'racing cars:master pieces of engineering' by j. Tipler
of course any 'ferrous material' from the supertouring.co.uk
website can be interped as any carbide/iron/steel alloy or what have you-perhaps i am mistaken as i am thinking of 85-91 ...

[redshoes]

FIA regs (Article 262 - Technical Regulations for Supertouring Cars, if you are interested) state..

1.15 Ferrous material
A material containing at least 80% of pure iron by weight.

4.6 Brakes
4.6.3) Brake discs :
Brake discs must be made from a ferrous material.

[gttouring]

ah bravo- this setles little- however the carbon iron discs does that include actual rotors? 80% iron by weight even if it is 2 pieces? a center steel and outer carbon ring?

[Invader]

You're mad Mr Touring, or should I call you GT?
Carbon is not ferrous...we are made of carbon and would surely rust in our inclement weather if we had too much iron. BTC brakes are made of steel. The regs would probably allow a carbon centre mount with a steel friction surface but that's about it.
The pads are made of old cornflake boxes stuck together with glue.

[gttouring]

NO I am not mad- i am really not getting across what i am thinking.
But the friction surface is in question then. I believed the friction surface was carbon or Carbide (which is a compound of carbon and a more elctropositive element) so that is my miscommunication. I read the book and the regs and these were my conclusions- i could very well be wrong and I applaud everyone for bringing the truth to me and the resources which back it up. question to further the argument however-Carbon rear brakes(or carbide) and carbon pads or cornflake box pads or vegemite paste- on the rear of these supertourers would not get enough heat to 'grab' properly, so the discs would retain any heat built up to keep them at operating temperatures, is this correct?

Of course we can shelve this and just say aero benefit I'll head home in shame.

[supertouring]

Your argument is reasonable, ignoring the carbon issues (I'd better stop taking showers if rust is a possibility). If it was only an aerodynamics issue then would it be reasonable that they run them on the front as well as the back? There must be another/additional reason for them and getting heat into brakes sounds like a good one.

Now, who is going to provide the evidence we need to confirm this?

[gttouring]

I know carbon doesn't rust, I am glad you saw what I was trying to say.
Iron (Fe) rusts (Fe++,Fe+)
ferrous giving the Fe to the periodic table (or ferrum? or feric oxide?)
It's been a while. Carbon doesn't rust iknow that wasn't my point how did we get on this anyway? And yes we are mostly carbon and water.
Our Hemoglobin has iron- It turns red whenit binds Oxygen! which is why Iron gets orange-ish as it rusts it binds Oxygen.
I amNOT saying we are rusting from the inside. I was just pointing out that I do know something about it is all- please mercy

[Invader]

Do you think that because we always run at a fairly constant temperature, we don't rust. I consider this as you correctly point out we do have an iron content in our bodies along with lots of water (Guinness in my case)
I agree that we should return to topic and find evidence of the initial reasons for these solid wheel covers and why they were only used on the rear.

[Hammerwerfer]

I can remember in the 70s they were using wheel covers that looked like that and the wheel cover bit was actually a sort of centrifugal fan which drew air out from behind the wheel. I believe that they were banned in most forms of racing at one point. Rather than heat the discs, they were actually cooling them.

[Hammerwerfer]

An example of the fan wheels:

[Hammerwerfer]

Didn't work, did it?

[Invader]

I'm not sure the geocities host allows cross-fertilization of images.

[Invader]

Funny looking semi-Martini Porsche with rather odd dayglo rims.
If they had painted them black, maybe they wouldn't have drawn so much attention.

[Invader]

Tyres are limited to 9in (229mm) wide and 25.6in (650mm) in diameter. Any form of heating devices are banned. Each of the national championships have slightly different regulations concerning the allocation of tyres. For the British series each car is limited to 6 slick (untreaded) tyres per race/qualifying session. In the event of rain wet weather tyres are not included in this total. The car must maintain the original suspension design, but points may be moved.

[Invader]

Yes I know that means tyre warmers, ask James Thompson.

[gttouring]

I still maintain, that the discs were used to maintain the rear rotors at there proper operating temperature as the touring cars were so biased to the front. If it was aero IMO all wheel would be covered in solid 'piedish' smooth caps.

[kmchow]

I would have sworn that in '99/'00, the BTCC or some ST series finally allowed tyre warmers? OTOH, the rules seem to say otherwise??

[supertouring]

From my web site again:
Initially, the use of tyre warmers was not permitted, but this rule also changed in 1998 to allow the teams to use them in the pits but not on the grid before the race.

[KA]

Originally posted by Invader
Funny looking semi-Martini Porsche with rather odd dayglo rims.
If they had painted them black, maybe they wouldn't have drawn so much attention.

Porsche 935/78 aka 'Moby Dick'- http://www.geocities.com/simontmalle...2/IMAG0010.JPG


I remember something similar being used in rallying as well-Austin Rover ran similar discs on the Metro 6R4 on tarmac events during 1986.

Group C sportscars also ran with discs on the wheels- particularly Porsches:

http://www.928porsche.net/956.htm

I think I've also seen photos of similar BBS wheels with discs used on a Group A BMW 635 CSI

I'm pretty sure the object in this case was to direct cold air to the brakes- there was a gap between the edge of the disc and the rim, and usually some kind of rotor effect behind- tended to be used on front wheels only, although sometimes all 4.

I thought the discs on Supertourers were fitted flush to the rim, so presumably we're looking at something different?

[touringlegend]

Tyre warmers were banned for the 2000 season and are still not allowed (i think?)

[Hobson]

The point of the discs on the rear wheels was aerodynamics. The brake bias on ST's was about 80%/20%, so the rear brakes were hardly heated up. The fronts on the other hand needed lots of cooling, and discs on the front wheels would have cooked the brakes in a few laps.

As there was little cooling neededon the rear wheels, I think it was BMW who thought about the aerodynamics of discs on the rear wheels.

[Invader]

That is the logical and most probably correct answer...thanks Hobson.
Now do we know whether they were banned and if so, when?
...or were they simply too ugly to survive?

[touringlegend]

They were still used up to the end of 2000, so I presume when the 2001 regs were introduced, the wheels are all the same because they are one of the "common parts" of all the cars..

[Hobson]

Thats what I thought too, universal parts to keep costs down. Not sure how much a set of wheel discs would cost.

I thought they looked pretty good, especially Matt Neal's discs with 5 'spoked' cut outs!