RE: Brembos, big reds, etc. (The truth and long)

[Greg Amy <grega@pobox.com>]

> Do not have the specs on the Boxster monoblocks. They appear 
> to be similar
> in size to the small 4 piston 944 calipers.

4-piston monoblock design. Leading 2 pistons on each caliper are 38mm
diameter, trailing 2 pistons are 40mm.

Pad is 53mm high x 110mm straight across (about 4.3"x2.1") for a total area
of about 5830 mm2 (9.0 in2) per pad. The new pad depth is about 11mm.

The rotor is 314mm diameter by 25mm thick.

> Appreciate the porsche history, and am very aware of the 
> sizing, why exactly 
> chosen  for conversions.  Audi owners should feel no 
> reduction in pedal 
> travel to engagement with new pads, however, my statement 
> remains, as your 
> pads wear with 4pots, the pedal loses height a lot faster v 
> G60's.  My only 
> meaning.  

Why? That makes no sense. Why would the pedal drop as the pad wears? Every
time you lift the brake pedal (and pull back the master cylinder piston) any
area that was occupied by the extending piston would be filled with
hydraulic fluid. Every time you use the brakes, the pedal will therefore be
in the same position.

Of course, if you stayed on the brake pedal and never lifted it for the
entire wear of the pad, then you will run out of travel. Simple hydraulics.

The only departure from that is as the piston extends, less of its length is
suported by the bore, and the piston could therefore be considered less
stable, which would effect brake feel. I have to imagine, though, that any
design by Porsche/Brembo would have taken this into account and designed
accordingly.

You know, I do have to step on my soapbox for a moment. A lot of you guys
seem like a bunch of wankers.

Why do I say this? Simple. You sound like you're each trying to "one-up"
each other as to who has the biggest....brake pistons. You remind me a lot
of the SUV crowd: they buy these monster trucks to use to simply go to the
grocery store, all under the illusion that "maybe" they'll have to dodge a
log truck or a falling boulder on the way to the mailbox.

Brakes on our cars are the same way: how much do you NEED for the street? To
hell with what you WANT for the 30 or so laps you do at a Quattro club each
year; if you were serious about auto racing as I was several years ago, you
would have spent the money and bought a SPECIAL PURPOSE race car, not
something to drive around in to get an event decal. I raced *24 hour enduro
races* on brakes that you would CRINGE at using. I would have killed for
something as good as the G60 brakes. Now we're sitting here deciding if that
extra 13mm of brake rotor diameter and that 5 square inches of pad are is
really going to make a difference in our lives.

OK, fine. Mine's not as big as yours. You win.

Bottom line: if you want to drive around off-road, buy a full-size Bronco
with the hose-off interior when you get it dirty, and save the
leather-couched Expedition for the gentile set.

If you want to go racing, buy a race car, and spent big bucks on that,
because if you spent on a race car what you're spending on hop-up brakes for
your STREET CAR then you have a pretty damn good chance of doing well. And
not just against other Audis with only G60 (or Boxster) brakes. Money Talks,
Talent Walks, bunkie.

Porsche GT2 brakes on a street car! Christ I wish I had that kind of money
when I was racing...