[s-cars] HPDE Track Tires

[manuelsanchez at starpower.net]

Taka,

To date I have always run a street tire at the HPDE events, and some of the tires have indeed chunked. If I went Pilot Sport, I would have them shaved, which I understand would help the chunking problem a bit (how much I don't know).

I was supposing that the wear rating of a tire was indicative of how soft the compound is, and thus, presumably, a softer compound would mean a stickier tire.

Aside from the chunking, any thoughts about my ambient temperature and camber setting comments? I realize I'll need to be even more careful in taking the time to properly warm up an R Compound tire, but never having used any I don't know if on a 50 degree F morning that will take 2 laps, 4 laps, 6 laps to do, or if because Ms Piggy is so fat, they will be warmed up in no time.

Is a R Compound tire on a car with street alignment going to perform noticeably better than a high performance street tire 
with street or -1.5 degrees of camber. Is the performance gain mostly non chunking tires or other.

tIA

Manny
---- Original message ----
>Date: Thu, 13 May 2010 13:07:15 -0400
>From: Taka Mizutani <t44tqtro at gmail.com>  
>Subject: Re: [s-cars] HPDE Track Tires  
>To: Manuel Sanchez <manuelsanchez at starpower.net>
>Cc: s-car-list list <s-car-list at audifans.com>
>
>   Get the ra-1. It you run those Michelin tires at the
>   track, you'll just chunk them. Wear rating is
>   irrelevant at the track- overheated tread chunks
>   will just wear right off.
>
>     On May 13, 2010 9:41 AM, "Manuel Sanchez"
>     <manuelsanchez at starpower.net> wrote:
>
>     Fellow S-heads,
>
>     I am looking into purchasing a set of tire that
>     will mainly be used
>     for HPDE events. I typically go when it is
>     relatively cool outside.
>     This is typically 4 track days per year (April and
>     November). Often
>     the mornings are cold, 40-50 degrees F (4-10C) ,
>     warming up to low
>     70s F (22C).
>
>     I have currently been running Toyo T1Rs and I
>     didn't really like them
>     too much. I am probably over driving them. They
>     howl alot and the
>     sidewalls really roll over (in my opinion). I
>     sometimes run stock
>     camber, but other times run -1.5 degrees of camber
>     (I actually don't
>     know what the limits are of my 2B Camber plates
>     are). I am running
>     2B's coilover kit with 600lb rear springs and I
>     think 440s in the
>     front. Koni Yellows, adjustable in the front.
>
>     So while I'd like to ratchet up my performance a
>     bit at the track, I
>     don't have a Donald trump bank account, so price
>     will be a
>     consideration.
>
>     When I took my Toyo T1R's to my reputable tire
>     dealer, he said these
>     tires weren't really designed for what I've been
>     doing to them, and
>     recommended Toyo RA-1's (instead of the R-888)
>     when I am ready, as
>     the RA1's have proven to take a beating (I have an
>     Avant).
>
>     My wheel size is 17" x 8".
>
>     I am looking likely at 245/40-17 (I currently have
>     235/45-17's).
>
>     Most of these DOT R compound tires seem to hover
>     in the $250/tire range.
>
>     Tire rack has a special for Michelin Pilot Sport
>     PS2's for $167/tire.
>     That's essential a buy 3 get 1 free deal compared
>     to regular price.
>
>     The delta between a DOT R compound and these is
>     about $332.
>
>     I have read in GRM that to really get the most out
>     of a track tire,
>     you need to run lots of negative camber. Toyo
>     lists -2.5 to -5
>     degrees camber on their website. I have run -1.5
>     degrees of camber
>     (don't know if I can set my plates up to get more
>     or not). I also
>     drive my car to the track and that's usually a 500
>     mile round trip
>     each time, so I have thought  that more
>     aggressive alignment might
>     chew up the tires I use to drive down a bit (the
>     beauty of the avant
>     as a track whore is that a complete set of track
>     tires fits
>     comfortably where the 3rd row seating is located).
>
>     The Michelin PS2's have a wear rating of 220.
>     Toyo RA1's have a wear rating of 100.
>     The Michelins are about 3-4 lbs lighter / tire
>     than the Toyo's.
>
>     So:
>
>     Has anyone run either of these tires on their urS
>     at the track?
>     If so, what did you think of them?
>     Based on my experience with the T1R's I would like
>     to find a tire
>     with a sidewall stiff enough that it won't roll
>     over (I have had
>     other tires that did not seem to roll over onto
>     the sidewall as
>     easily as the Toyo's, Goodyear F1 GSD3's and some
>     Dunlops that I
>     can't remember).
>     Would an R Compound tire be a waste, since I have
>     not run at least
>     -2.5 degrees of camber?
>     Would R Compound tires be a waste because the
>     track temperatures when
>     I attend HPDE's is cool (in my opinion), or are
>     those ambient
>     temperatures warm enough to get an R compound tire
>     to really shine?
>
>     I could also let this PS2 sale slide by and when
>     the time comes buy a
>     cheaper set of Hankooks or Kuhmo street tires to
>     beat on at the
>     track. They seem to be substantially cheaper.
>
>     Thanks.
>
>     Manny
>     95.5 urS6 Avant (mostly RS2'd)
>
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