mk1-forum.net

hello all
while recently preparing my 65 cooper s period rally spec car for its anual mot , i noticed that the front brake disc backing plates were missing.i had not noticed this when i brought the car a couple of years ago.The car is built to a very high quality spec using all period parts.i would be amazed if the owner at the time did not request these to be left of judgeing at the detailing of the rest of the car.
My question is has anyone had experiance of these plates being left off of rally cars in the past? I can only assume it would be to do with heat dissapation or that they are simply missing.
I am intrigued on your views.
regards
Mark

the backing plates are there for two reasons, 1) to help keep dust of the wheels, 2) to keep the discs dry etc to help with the first application of the brakes.


neither of which are much of a concern on a rally car!

Never fitted them to any of my rally cars. Also stops small stones etc getting trapped between the sheild and the disc.

To be honest, I can't recall whether I ran my rally S with backing plates. I think not.

Experience with Escorts and other cars is that fitting backing plates is a question of "horses for courses". On tarmac events, where brake cooling is vital, Group One cars like RS2000s (Gp1 regs did not permit removal of backing plates) tended to have the backing plates "fall off" just after the start and miraculously re-fit themselves just before the finish.
Conversely, on a long wet gravel event like the RAC, removal of backing plates would allow one of the pads on each side to wear at about three times the rate of the other one - because of erosion from a "paste" of wet sandy mud. The same substance would eventually get into the wheel bearings via the seals. After the (wet) 82 RAC my front bearings were seized after the car was parked. In 84 I fitted the disc shields and had no problems. On the 72 RAC, Roger Clark had a front wheel bearing fail on the final road section (and only won because Cowan's retired car was running chase and could be canibalised in time). In 1984 Des O'Dell was showing me round a works Group B Samba and pointed out the alloy shields fitted behind the rear discs "because last year we had problems with wet sand". So even works teams learnt the hard way...

I would definitely leave them off when building any competition car.

Hi,

for a competition car the only important thing is cooling the brakes. Therefore you may consider constructing an air duct leading in something like a backing plate.

They can also fall off :/ My mate lost one on way to bingley last year Lmao so runs with out any now we just found a mark 4 polo and too the plastic vents off one aids cooling to the brakes


Vw polo's have plastic vents on them to cool the brakes dircet air in

bit of a mod to fit em but work not 100% sure if still on cause barely talk to him now.

mk1 wrote:I would definitely leave them off when building any competition car.

Which would be very silly in a few specific cases.

Sometimes not sure what point there is in posting the sort of thing I wrote above if no one takes note of it......

Think should read LMM 76C post again, he gave some very good information from personnal experieance,
its real facts, not guesstimation.

vortz racer wrote:Think should read LMM 76C post again, he gave some very good information from personnal experieance,
its real facts, not guesstimation.

as did i

but i guess the experience i have of running race cars, autograss cars and a deathtrap semispace frame rally car dont count.......

it counts

The answer to the question is in another question, what do you use the car for ? Seeing as most people that own period rally cars either use them for road rallies or not competatively at all I'd say it barely matters what you do with you dust covers !

On a road Mini without the disc covers when you first apply the brakes after travelling some miles without using them on a wet motorway it can be quite scary to suddenly find a lack of any 'bite' when they are applied.........

i only use the car on the road but i do like the fact of everything being right about it, my only concern was if they were missing by accident, reading the posts it is quite clear that they are meant NOT to be on this particular car, although i do take note about the first application of the brakes in the wet.
thank you all for your experiances.

Interesting thought.

Let's cut to the chase here. If you have a shunt and kill someone and the insurance company find them missing. Do you end up in a world of liability?

I have never fitted them on any of my cars. I have also never noticed the brakes being anything more dramatic than they usually are.

I haven't driven a mini on the road for a while, as it's been in the shed, but I remember my last excursion after driving a servoed modern car and jumping to S disks, fast road pads and no servo! press, PRESS, PRESS MORE!!!!!!!!

I've forgotten what it's like to stop a speeding mini.