Final thoughts on this caliper/rotor thing, Please keep going!

Avi Meron avim at
Tue Nov 20 19:41:37 EST 2001

Please "other guys" let whoever wants to discuss this subject

I for one think it is very interesting and I enjoy reading about
it...........(sorry I don't have anything to contribute!)

If someone does not like it, please hit delete!

You all take care now,

-----Original Message-----
From: quattro-admin at [mailto:quattro-admin at]On
Behalf Of QSHIPQ at
Sent: Tuesday, November 20, 2001 2:23 PM
To: quattro at
Subject: Re: Final thoughts on this caliper/rotor thing

I'm the village idiot.  I also look at claims with numbers alot, always have
on these lists (I love em), on this topic and your claim just created extra
interest.  Michael to wit, using YOUR friggin numbers and claims from them:

The PF pad you are about to install in a customer Big Red Caliper.  Let's
thru YOUR numbers at min spec on a 32mm rotor:

PF pad as measured by MGW on 11.08.01
25% x 10.3mm pad = 2.575mm of pad x 2
5.2mm of backing plate x 2
Add 30mm (min spec of Porsche rotor)
5.150mm + 10.4mm + 30mm = 45.55mm between pistons (your other math confuses
me, this is simpler) at piston stop

Stock Porsche 993tt pad as measured by STJ on 11.20.01
Let's go to a porsche Textar pad with a 30mm Audi rotor:

25% x 10.3pad = 2.575mm of pad x 2
5.2mm of backing plate x 2
1.50mm of anti squeal plates x 2
28mm min rotor spec
5.150 + 10.4 + 3.0 + 28 = 46.55mm between pistons

I look at the above vs your posts and propose that putting a PF rotor on a
set of Big Reds attached to a porsche 32mm rotor assumes more risk of piston
extension failure and boot failure than a Stock Textar pad on an Audi 30mm
rotor.  Each piston at min spec will extend .5mm further on the min spec
porsche setup running PF pads.

MGW, THESE ARE YOUR NUMBERS NOT MINE. Stop scaring the trick or treaters.

Ease up Michael, you *obviously* don't have any idea what I have done, I
tell you I service them all.  I don't care what you do or have done, you
posted numbers, and claimed "risk".   Your claims aren't supported by the
numbers, nee, just incomplete.  Do you need *me* to apologize to you?  If
you'd like to make another claim, please feel free to post up those numbers.
Right now, if you still believe your "claim" I'd advise that you either
return the PF pads, or add A/S plates to them.  Obviously, based on your own
numbers, if you've been putting PF pads in Big Reds with porsche rotors (and
I know a bunch of porsche boys that do exactly this) without them, the audi
guy with 30mm rotors and stock pads assumes less risk associated with piston

Michael, I didn't see any "Warniing:  You must install A/S plates or risk
piston overextension" on the box of PF's in my shop.  How bout yours?

I thoroughly enjoy readings of "what you can do" for how much.  You're
it's not complicated.  I have seen many times over the years, that you get
what you pay for.

You crack me up.  Your claims don't, they just don't add up.  I won't attack
you Michael, I'm happy to attack your claims if they are number based and
don't support your conclusions.

Scott Justusson
QSHIPQ Performance Tuning
Old big red 44tq

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