rear brakes not doing their share on G60'ed urq

[Brady Moffatt]

Hi Javad,

No ABS, but I do have locking diffs. I was thinking of lapping the car with
the center diff manually locked. Wasn't that the consensus? In that case,
couldn't I increase rear bias a bit? On the street, unlocked, maybe lower it
a bit. Does this make sense?

I forgot to mention that when I bought this car at the end of March, after a
spirited test drive in the hills near Cincinnati, the front discs were
shiny, but the rears were not. As of yesterday, the car has cleaned-up rear
calipers, new rear pads and new rear rotors. Now things heat up a bit more
back there, I think, but the braking feels the same, which meshes with your
experiences.

I'll have to try a few panic stops to see what's really going on...

Cheers,
Brady Moffatt
Montreal, Quebec, Canada
83 UrQuattro with 51,000 miles
86 4ksq with 310,000km
86 4ksq parts car
72 Datsun 240Z with 180,000 miles
92 VW Golf with 200,000km FOR SALE
in middle stages of quattrosis accumulatus

----- Original Message -----
From: <JShadzi at aol.com>
To: ""Brady Moffatt"" <bradym at sympatico.ca>; ""urq"" <urq at audifans.com>;
""quattro"" <quattro at audifans.com>
Sent: Thursday, May 08, 2003 5:52 PM
Subject: Re: rear brakes not doing their share on G60'ed urq


> Brady, you're pretty much right about the rear brakes, they do about 20%
of the braking/slowing at most.  You want to find that careful balance in an
Audi, because so much of the weight of the car is up front, the rear brakes
can get real "lockey" if you're not careful, which is much worse then them
not doing "as much" as the fronts.
>
> A proportioning valve will allow you to adjust this bias, but due to the
very dangerous and unnerving nature of locking up only your rear brakes, you
may find yourself at the balance you have now.  In my 80tq with 13" Big reds
in the front, I'm still using the stock bias, under hard threshold braking
you'd swear your eyes are being pulled out of their sockets, and I've never
been too concerned with what the rear brakes are doing so long they never
lock up, they're not contributing that much to the whole event of slowing
down anyway...
>
> Of course if you have ABS, then go as big as you want since the ABS will
keep things from locking up for you.
>
> Javad
>
> >Hi All,
> >
> >My still-new-to-me 83 UrQ has G60 front calipers, which work fine. It has
> >stock rear brakes which don't work as well. They heat up significantly
under
> >spirited driving (so they're doing some work!) but not nearly as much as
the
> >fronts. It really feels as if the fronts are doing almost all of the
> >braking. On Louis-Alain's 83 UrQ with stock brakes all around, braking is
> >much more balanced, and, I suspect, stronger.
> >
> >Have the G60 calipers' extra appetite for brake fluid unbalanced the
braking
> >system?
> >Do I need an adjustable proportioning valve so that I can get more line
> >pressure to the rears?
> >
> >Any other ideas?
> >
> >BTW, the car brakes straight, and nothing sticks.
> >
> >Cheers,
> >Brady Moffatt


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