Re: V8 quattro tyres

[Eliot Lim <eliot@u.washington.edu>]

On Fri, 11 Aug 1995, Frank Deutschmann wrote:
> I'm missing something: I thought that inboard brakes were used to reduce
> unsprung rate; with the rotors mounted on the chasis, and not the suspension,
> they are then sprung weight.

"internal caliper brakes" are not the same as inboard mounted discs.
in the former, the disc is very much part of the hub assembly and
very much unsprung.

the main difference between internal caliper and regular discs
are that the brake actuator assembly grabs the disc from the
"inside" of the disc as opposed to the "outside".  by doing
that you can have a larger diameter disc, which in turn increases
your swept area without increasing the overall diameter of the
assembly.

in those days, audi argued that 16 inch tires were difficult to
come by, which was justification for using these funky discs.
of course today it would have been trivial to simply put in
11 or 12 inch discs, which i think is what the A8 has.

the disc is carried by a welded shell and this is where all the
problems arise from insufficient cooling to double or triple the
unsprung weight.

that's a somewhat lame attempt to explain what they look like.. if
you can see the thing then it would be a lot clearer.. but they
are certainly not inboard mounted.  :)


eliot