[Shotimes] (OT) Michelin Pilot Sport Cups gone greasy

[Ron Porter]

FYI, for the track folks mostly....

Rick asked a question about the Michelin Pilot Sport Cup (MPSC) tires, then
after a long thread, he called Michelin and got the answer in the lower
post.

Ron Porter

-----Original Message-----
From: Richard Betterley [mailto:rbetterley@betterley.com] On Behalf Of
rick_betterley@rennlist.net
Sent: Thursday, May 05, 2005 1:28 PM
To: 911/993/996
Subject: Michelin Pilot Sport Cups gone greasy

Looking for experience with MPSCs (used for DE events on my '84 Carrera).
I have put 45 heat cycles (about 12 months) on my MPSCs; my first time using
them.  Not knocked out by their grip (previous tires were Hosier SO3s,
before they had the 04 problems), but acceptable if I get a lot of wear out
of them.
They were fine until about 35 cycles or so, but really went greasy right
away at New Hampshire this week (previous event at Lime Rock, they were
fine).  Pressures were same as at Lime Rock, both cold (25/26) and hot
(32-33).  Lime Rock was sunnier and somewhat warmer, but I don't think the
lack of a sunny day makes enough difference for what I was experiencing;
lots more sliding around, although not terminal by any stretch (kind of fun,
actually).
Tread still is good (such as it is for a DE tire), worn on outside half,
much less wear on inside.
Camber settings are maxed out as far as can be with factory suspension bits.
So, what are others experiencing in terms of heat cycles?  I hear reports of
50-60, so I am getting there, but wonder if I can expect 60, or is my '35
then you start sliding' experience typical.
Thanks; still wondering whether I go back to the Hoosiers.  How are they
wearing?

Rick Betterley

Had a very fruitful exchange of info with Michelin re my Sport Cups going
greasy after 35 heat cycles.
Here is what I have learned:
1) Michelin is very responsive to requests for info and advice; good follow
up and knowledge
2) More than 35 heat cycles is expected; they didn't give me number I could
expect, but it sounds like it should be well in excess of 35 They asked me
to run the existing tires at next event (Monday next at Watkins Glen with
Todd and Tracquest) and then call them to discuss results, since going
greasy after 35 cycles was apparently unusual.
3) Negative camber 1.3-3.0 is ideal (pretty wide range)
4) Cold hot pressures should be 25/26 or so, hot 32-33, which I have been
using (at least on a 1984 911)
5) Tire temps should be 160-220 hot; I need to borrow a pyrometer to test
this.
6) Flipping tires is not recommended, due to their asymmetricallity.
Hope this helps anyone else using these tires.

Rick Betterley
Rennlist and PCA Northeast Region member
1984 Carrera Coupe for the track (Guards Red #86)
1986 Carrera Cabriolet for the street (also Guards Red) 2000 F350 Diesel
crew cab duallie (tow vehicle) and 2003 CargoPro enclosed trailer