Re: type 44 brake question - long answer

["Frank J. Bauer" <frankbauer@thevine.net>]

At 08:30 PM 10/13/98 GMT, Phil Payne wrote:
>In message <3.0.1.32.19981013101553.0073da5c@pop3.thevine.net> "Frank J.
Bauer" writes:
>> >Roger's car is the only one I'm really familiar with, and his
>> >proportioning valve is under the master cylinder in the engine bay.
>>
>> the device being referred to is a valve that is actuated by a lever
>> connected to the lower rear control arm that reduces braking pressure when
>> the rear lifts (unweights) under braking.
>> not likely to be located in the engine room...
>
>Betcha.
>Non-quattros have a rear torsion bar suspension, to which the device
>you mention is attached.
>Quattros have full rear Macpherson/wishbone suspension.  What do you
>attach your device to?

on the type 44 quattro, the bpr is attached to the rear subframe.
the actuating lever on the brake pressure regulator is attached to a lever
on the trapezoidal (lower control) arm with a stiff spring.

>The engine bay device contains a large mass ...
perhaps you are thinking of the abs unit.
i cannot picture any device resident in an audi engine bay that is capable
of judging the attitude of the rear suspension...

frank

ps - perhaps a later evolution of abs controlled the rear bias with the
help of an accelerometer...