[Biturbos4] stoptech vibration

[Robert Cheng]

A while back I took my Stoptechs to Road Atlanta but used the Axxis
Ultimates that came with the kit.  I overheated the pads and the rotor was
covered with uneven deposits.  I took the rotors off and carried them to a
brake shop simply to see them spin on their lathe to see if they were
warped.  On the machine there was a definite warp so I put them on the shelf
and ordered new rotors.

[Fast forward a year or so] After reading some posts on Audiworld and after
many emails back and forth with Stoptech tech support, I reinstalled the
rotors on the car.  With the car up on 4 jackstands I cranked the car and
watched the rotor spin and it was steady as a rock.  I was told that the
only proper way to check for warpage was installed on the car, due to the
floating carrier.  As recommended by Stoptech I ordered some Hawk Blue pads
and installed them with my pad-deposited rotors.  After about 50 miles of
normal driving the old pad material had been worn off and the brakes were as
smooth as new.  At this point I decided I would have a separate track and
street setup and one set would go on the shelf with my Pagid Orange pads and
I ordered new Pagid Blue pads for the street (much quieter but still
aggressive).

So yes indeed it was uneven pad deposits on the rotor.  On my 2004 Nissan
Titan I had a similar problem with the brakes.  Many people were complaining
of a "brake judder" and the steering wheel and front end would shake when
the brakes were applied.  Nissan had a TSB out where the rotor was turned to
remove the old pad material and the pads were changed out to a different
type.  Bottom line is Nissan originally installed pads that were not of
sufficient heat capacity to withstand the brake force necessary to stop a
5000+ lb vehicle.  Perhaps some of you simply need to try a different and
possibly more aggressive pad.

Rob
'00 S4 6-spd
'04 Nissan Titan
'98 VFR800
'90 HawkGT


> -----Original Message-----
> From: biturbos4-bounces at www.audifans.com
> [mailto:biturbos4-bounces at www.audifans.com] On Behalf Of Quincy Chiang
> Sent: Monday, September 06, 2004 1:24 AM
> To: Single Malt
> Cc: Biturbos4 at audifans.com
> Subject: Re: RE: [Biturbos4] stoptech vibration
> 
> I have this same issue on my stock brakes on my '90 CoupeQ, steering 
> vibrates whenever I hit the brakes at over 50 kph.
> It's been a few years now, replacing pads and discs only cure it for a 
> few months, still haven't found the root cause.
> 
> On the S4 however, I've read on the AW forum that it's most likely 
> uneven brake pad and pad desposit on the discs, as the discs 
> themselves seldom warp.  I think a few folks managed to fix the 
> problem by doing a proper bedding procedure, basically doing a bunch 
> of 80-5 mph stops with minimal cooling in between.  Go to Stoptech's 
> site for a full description of the procedure.
> 
> I'll try that on my coupe and see if it helps.
>