Corrado Brakes -- Physics Question: Are they pointless?

[16V JASON <jason@scirocco.org>]

At 02:33 AM 2/4/99 , Riley McDowall wrote:
>At 11:19 pm -0800 3/2/99, Jason wrote:
>>Does anyone know exactly what's involved in installing corrado brakes on
>>an 87 16v? Are the calipers much better? Is it worth the trouble?
>>Brackets/spindles different? If I remember correctly the corrado has 11"
>>brakes and the rocco 16v is 10.1"??? I'm going with ATE super blue brake


Okay... this is a subject that I've been debating with someone behind the
scenes for the past month or so.  It is my opinion that putting 11" brakes
on a 16v is redundant.  Why?  Because 10.1" rotors are already enormous on
a car that weighs 2370lb.  My argument:

The Audio 90 20v has the same brakes as the 16v Scirocco does: 10.1" in the
front and 9.6" solid in the back, single piston calipers.  It weighs
3200lb.  It outbrakes a stock Scirocco 16v.

The Mercedes S600, which weighs just under 5000lb (DOUBLE a 16v) and has
389hp and 420lb-ft of torque, and which has to be restrained electronically
from doubling the speed of sound :) can brake from 70-0 in 182 feet.... and
does it with 12.6" rotors.

The Ferrari 348tb will stop 3300lb from 70 in 177 feet with 11.8" front
rotors.

Okay.. Riley.. uh, I mean, this person with whom I have been debating this
point offline, said that maybe the Mercedes uses a 2 or 4-piston caliper,
which would help braking force.  That's a valid point.  

But! The Audi doesn't.... it uses the same calipers as the 16v does...  So,
how can we justify needing 11" brakes on a car that only weighs 2300, when
the Audi weighs 35% more and is *still* considered an excellent braker?

True, the increase in swept area will give the brakes more initial bite..
but (and now we come to my point), isn't the braking distance of a car
limited essentially to the tires' ability to grip?  I mean, I'm sure I
could do 200 km/h (125mph) in my 16v and lock my front wheels up instantly
(not that I would want to, of course)... so what good would bigger rotors
do? If the rotors can overpower the tires (which they can, if they can stop
the wheel from turning), what's the point of having bigger rotors?

I think it's safe to say that, with Ferodos or any other high-quality brake
pad on them, you would have to *really* try to overheat the 10.1" brakes on
the front of a 2300lb car... especially with the breezy aftermarket 15s,
16s, and 17"s most of you have on your cars...  Even with my teardrops,
I've never come close to overheating mine with the Ferodos.  The MMs were a
different story... but it still took a *lot*...

So, with that said, and thus neglecting the fade factor, what's the benefit
of upgrading to 11" brakes?  As far as I can see, the only benefits are
fame (people saying "You're cool!"), and that's surely outweighed by the
cost (ouch) and the increase in unspring weight.

Opinions? Comments?

	Thanks!
			Jason



----------
jason@scirocco.org
1987 Scirocco 16v
57,000 original miles.
http://members.aol.com/rocco16v  

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