Re: Upgrading everything else

[ti@bazooka.amb.org (Ti Kan)]

gt6493c@prism.gatech.edu wrote:
>How hard was it to add rear-disc brakes to your 4000?
>I have an '85 Coupe Gt, and have been thinking of putting
>rear disc on.  Since the 4000 and Coupe are so similar, I
>assume your method would apply to my car.
>Also, about how much did it cost and where did you get
>the parts (at a local junkyard?)?

The suspension on the FWD Audi 4000 and Audi Coupe GT is identical.
Thus, you can make the same modification as I have done.  What I am
describing below does *not* apply to quattro models.

If you have 9.4" front discs on your Coupe (some Coupes comes with the
the 10.1" brakes standard), then upgrading the front brakes to the
10.1" unit will yield a much greater improvement than doing the rear
disc conversion.  The 16V Scirocco rotors and calipers will bolt on to
the 4000 front suspension with no modifications.  You do need 14" or
bigger wheels to clear the 10.1" brakes.

The 10.1" front brakes can be bought from many VW recyclers for around
$300. The rear disc brakes usually sell for about $250.  Add a little
more to get resurfaced rotors and Repco MetalMaster pads.  For the rear
rotors, you should also get new wheel bearings and have the races
pressed in to the rotor by a brake shop before you install it.
You can also buy these parts new from outlets like Automotive Performance
Systems, Autotech, or other VW Performance shops for substantially more
money.

To make the rear disc brake conversion, you will need the stub axles,
the brake rotors, calipers, splash shield and a few other miscellaneous
pieces from any 85-92 VW GTI or GLI or 87+ VW Scirocco 16V.  You will
also need to get a pair of flexible brake hoses for the rear caliper.
The best thing to do would be to get a set of the stainless steel
braided teflon brake hose kit for the Scirocco 16V, available from many
VW performance shops.  You also need ample brake fluid.

You will have to do minor fabrication here.  Buy some hard brake line
material from the dealer.  The original hard brake line on the
suspension trailing arm will not work, as it leads to the position
where the drum brake cylinder was.  You will need to have two small
metal brackets fabricated and welded onto the suspension beam just
under the brake calipers.  You need to form the hard line and flare the
ends, and then mount it to the the suspension beam, one end to the
original flexible hose (or the new steel braided hose) at the trailing
arm hinge, and the other end to the bracket you added, which should
then be connected to another flexible hose (or steel braided hose) that
leads to the caliper.  If what I'm saying here isn't crystal clear,
just look at the way the rear disc brake lines are mounted on the VW
GTI/GLI.  In fact, the brackets can be modified from the clips as used
on the GTI/GLI.  It's really not real difficult.

The stock parking brake cable will work just fine, but you'll need to
readjust it for proper tension.

You may need to adjust the brake proportioning valve to re-establish
proper braking balance.

Good luck...

-Ti
--
    ///  Ti Kan                vorsprung durch technik
   ///   AMB Research Laboratories, Sunnyvale, CA. USA
  ///    ti@amb.org
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