Bigger brakes on a Audi 200...

[David Glubrecht]

  I have started this upgrade on one of my non-Audi's.  A larger rotor with
the stock caliper will quite effectively improve brake performance.  But
there is a few problems one must address.

 #1 Finding rotors, They must be correct in many dimentions  bolt pattern,
hub center, thickness and offset (the amount the rotor face is behind the
mounting surface). It would be nice for the offset to be a little more as
the easiest way to make adapter brackets will place the calipers back a
little, but you need to be carefull of clearance issues.
 #2 Building brackets, As per above, bracket must place caliper properly on
rotor and can be difficult if the rotor doesn't allow the caliper to be
placed inward.
 #3 Weight, you are not improving things here!
 #4 Ballancing, This is critical. otherwise known as bias. If you increase
the front the same as the rear, you will not change the bias much.  As far
as I know all cars have perportioning valves and they can be adjusted
(sometimes) or they can be disabled or removed and an adjustable one
installed (Wilwood sells one for $59).
 #5 The brakes must fit under your wheels, however on my car the brakes fit
under 14" wheels and I only used 15" anyway, and this was the improvement I
could find that fit under stock 15" wheels for my car.
 #6 This should really be #1 You are designing your own brake system and it
MUST be right, as we know brakes are very important.

  I will consider this upgrade to my Audi, but I am very happy with the
brakes on my Audi and was never even satisfied with the brakes on my other
car http://www.pelkie.com/mycars.htm
 So far, while not completed, I have yeilded a vast improvement.  I had
hoped that removing the perportioning valve and allowing full fluid pressure
would compensate for larger rotors on the front only, however the
improvement was much greated than the perportioning valve was limiting the
rears, so I need to do the rears.
Here is a link to a page where someone has completed this to their non-Audi.
http://www.webelectricmagazine.com/99/4/brakes.htm

  Dave G


> Hi!
>
> A set of G60 calipers has shown up over here and I put my name down on
> the set. Now I'm thinking perhaps a larger set of discs would be in
> order. I run the usual 278mm front discs and I think the rears are
> 254mm. I was thinking instead of forking out so much cash on a set of
> Wilwoods or other replacement caliper, I could try and use the stock
> caliper or the G60 2-piston units with a larger disc up front. Ofcourse,
> I'd have to have brackets made up to move the caliper out a bit, but
> what do you guys reckon would be the effect on braking with a stock
> caliper and pad on a larger rotor. Swept disc area would increase, but
> the clamping area would be the same (same pad remember).
>
> I wish the G60 had shown up a year or more ago before I bought myself a
> set of Ate PowerDisc units for the front, a set of standard Ate rear
> discs for the back and then rebuilt the stock calipers. But just looking
> to ideas for the future as usual.
>
> Who is running something like this? Would a larger front disc and a
> larger rear disc lend towards more rear brake lockup or would that all
> be taken care of by ABS and the brake pressure regulator on the rear
> axle?
>
> Anyone ever put the front discs on the rear to get bigger ventilated
> rear discs? :)
>
> Silly ideas abound.
>
> G.
>
>