PCA SDR

Im buying a second and 3rd set of these tires for next year.

My initial reaction is not to shave them (seems like a waste).

But I have tlk ed other that say shaving them to 5/32 or 6/32 actually helps them last longer and are less prone to chunck in the treads under hard use.

I know a lot of you use these tires....

What do you prefer?

What lasts longer for track use?

RA-1's do not need shaving to last a long time. They will last a long time no matter what you do. However, they do squirm around alot at full tread, so you will not get optimum grip until most of the top tread blocks are worn off (basically down to 4 longitudinal grooves). RA-1's shaved down to the grooves are fast right out of the box.

You are not supposed to need to shave R888's because the tread pattern is more closed. They are different from RA-1's in that it seems that they have a heat cycle limit, and then they lose grip. But I'll defer to others who have more experience with them.

soooooo..... shave them or not?

The Toyo RA1 is the better tire IMO. Depending on if you want to be that extra tenth faster than your competitor, then you should shave the RA1 at 4/32 or 6/32. BTW the R888 comes from the mold at 6/32.

The RA-1 will usually not chunk, so if longevity is your goal, run them at full tread depth, knowing that you won't have optimal grip until the tread is half gone (not a bad tradeoff for a track weekend, especially if you drive your car to the track). Heat cycling with the RA-1 does not seem to be an issue, as many of the guys in the club run them until they cord (pick a shoulder, depending upon your camber setup). However, if you want them to be fast right away, then shave away...

If you talk to the tire reps who sell the Toyo's they will tell you:

" The theory behind shaving is about heat management. With the RA-1, the tire does better at extreme conditions when shaved. The heat-cycling is more even and the internal molecular damage to the compounds are less severe that a full-depth tread tire that can hold the heat longer and sustain more damage. So while counter-intuitive, a shaved competition tire will tend to last longer and have better grip over the life of the tread than a full tread tire driven at extreme heat/driving conditions."

Experience from many competitors ... myself included ... has indicated that the RA-1 lasts all the way to the cord vs. the R888 that fails with anywhere from 2/32 to 3/32 of tread depth left. Nothin more disconcerting than throwing away a tire with 3/32's left.

When the RA-1 fails, it's gradual. The R888's on the other hand ... a light switch when their done. On a big track ... scary!

My thoughts..... others will likely disagree.

I have run both on a medium-weight 911.

I have never shaved the R888, and I think Toyo does not really recommend that anyhow.
As Russell mentions, the R888 has a much wider tread block, so is less prone to squirm,
and hence, it doesn't seem like it would really be a benefit to shave them.

The RA-1 I have used many times, both shaved and not. For me the life is definitely less
with shaving, even though many folks tell me it should be otherwise. It may have to do
with driving style. Although I am not particularly tidy, I do tend to drive smoother when
the tires are new (for a few sessions), gradually getting a bit more lively as they age.
From the time my RA-1 tires are down to 4/32", they'll last as long as a new shaved set,
but I've already been able to put a lot of track miles on them.

In my experience, the R-888 is a slightly better tire brand new, but as others have said
it falls of a cliff when there's still a bunch of tread left. Well, it's not completely shot,
but I find it has decidedly less grip after the first couple of laps in a session, but still
works okay for timed runs (Time Trial) or Autocross. Based on this, one might think
that shaving them would be wise. Then at least when the R-888 dies from heat cycles,
the tread is gone so you don't feel so bad! Still, I don't think it would help to shave it.

I really like the RA-1 for its long, predictable life, forgiving feel, and overall economy.

I have run both tires on two cars, a 944 Spec and a 944 Turbo S. I have never shaved the R888, but have used RA-1's in both shaved and full depth.

First the R888. Not only are they not worth shaving, they are not worth buying for a So Cal track tire. They cannot take the heat. On the street they are OK, and in the north east where it is rainy and cold, they seem to work. Here, as Paul said, they are great when new at 2 - 6 heat cycles. Then OK from approx 7 -12 heat cycles, then they lose grip even though they will look OK. Their "heat cycle" death is much worse on a more powerful car. They also fall off faster if your driving style is "less smooth". It seems that if they are severely overheated, even once, they are never as good again. If you want a great tire that has a short life, then the Hoosier R6 or Kuhmo 710 have better grip and a similar life expectancy with a similar cost (size dependant).

The RA-1 is great! As Dan and others have said, it is not overly effected by heat cycles and doesn't chunk. It has grip until just before if cords (I am very experienced with this!). The main difference with shaving or not, is that the tread does squirm quite a bit on the track with the unshaved tires. This generates a lot of heat (See Dan's story from the Toyo rep). The extra heat does cause it to lose grip faster when hot and does sometimes damage the tread somewhat. After it cools, it seems to be OK again unlike the R888. So, on the track, it is initially much slower than the shaved tire. After they are worn to about 2/32's they both perform similarly. So, the unshaved seem to last a little longer overall, but the initial use has less grip and overheats quicker, so the use is not "track friendly". Also, the performance between the two cars is similar from a heat cycle perspective. The turbo wears them faster, but that is because it is spinning them constantly.

If you have the luxury to use an unshaved set on the street or for practice, then you may want to consider having one set unshaved. If you are only going to use them on the track and do not want to keep changing tires to manage their wear and only use the "good" ones for the timed runs, then it is simpler to just shave all of them and know that you will always have consistant grip and performance until the steel belts have to try to grab the asphalt.

For a track 997 - shave them!
My $.02

To summarize, buy the RA-1, shave them, but do not heat cycle. Drive smoothly and expect the rears to wear out well before the fronts.

WARNING: you are approaching the slippery slope! The Kuhmo/Hoosiers aren't THAT much more and really are faster

Thanks Guys.

Im going to buy a set shaved and a set un shaved to see the difference myself.

These are going on a track prepped 997S

Last set was R888, Im excited to try the RA1's


Jad,

I know the Kumho and Hoosiers are faster but, I want to learn to drive my car at the limit with these (as I did with street tires) and them move up to hoosiers.

My suggestion is don't get either unless a rules requirement.

I'd go with Nitto NT-01, unshaved.

They have better wear than either and same or better grip than the 888.

Here is a thread on Pelican about the 888s. A lot of really good information.
http://forums.pelicanparts.com/porsche- ... em-up.html