Date: Thu, 17 Jun 1999 09:05:17 -0700 (PDT)
From: Andrew Kalman <aek_at_netcom.com>
Subject: Re: [E36M3] the allure of R4s pads and similar street/track pads

Jay asks:

>Here's where I need some advice: while people have great experience with
>the PF90 (and they're super easy to bed in), will I get brake chatter if I
>use the same rotors for the PF90 at the track and the R4S on the street?
>If I stick with the R4S for the street, should I get separate rotors for
>use with the PF90s or, to avoid having to swap rotors, use the R4 race pad?

Here's my experience: I replaced the Pagid R4-2-1's that I use for Pikes Peak with PF90s, and kept the same rotors. I did a test drive to bed in the PF90s, then drove 4 track days.

In retrospect, I may have not got the PF90s hot enough when I bed them in ... but my first day on the track (Laguna Seca), the shaking from the front end was UNBELIEVEABLE! It was like running over speed bumps, with side-to-side wiggle as well. Kinda scary. But Carl B. assured me that this was just the PF90s not having transferred enough material over to the rotors, and Todd G. backed him up ... but I remained a bit skeptical.

However, by the fourth track day (at Thunderhill) I was braking very heavily and everything had smoothed out. I never changed a thing, just tried to brake smoothly and hard, then really hard, then really really hard, and eventually the problem went away. Since I'm about to put the Pagids back on, I plan to dedicate this set of rotors to this set of PF90s to avoid this problem in the future.

I run w/out brake ducting, just with SSR wheels and Ate Super Blue. I experienced no fade whatsoever, although I did get some burning brake smells early on -- perhaps it was fluid that was left on the caliper after bleeding?

| Andrew E. Kalman, Ph.D. aek_at_netcom.com |
| standard disclaimers apply |
|___________________________________________|