Viken

I cannot believe you said that. There is night and day difference between those two tires. Clearly, you were not driving hard enough to tell the difference. Then again, you don't really have to drive that hard.

That is perfectly understandable given the fact that you thought both tires above were indistinguishable in terms of performance.

Steve in SLO

Viken,
I want to be clear before I go order the tires:
You think the disparity in age/tread depth between my front and rear tires is responsible for the behavior of my car even though the rear wandering is most noticable while driving in a straight line on the freeway.
Correct?
Thanks again,
Steve

Viken

Yes.

Timothy Stewart

Re John H comments above -
I believe that he is referring to the camber and toe eccentric.

Note that the shop manual (42-13)
explicitly says "check condition of threads"
and change the grade of bolts from 8.8 to 10.9.

The grade is stamped on the bolt head.

I had a similar problem when one of the 8.8's
had damaged threads and could not maintain
the torque value.

tim

Martin S.

Steve writes, "We have dialed out as much neg camber as this setup allows." I would think you would be dialing IN negative camber, not out.

Must also agree with Viken, replace the tires in sets, especially race tires. Regarding street tires, someone seems to be interested in used street tires, to each his own. I have sold off more than one set on Rennlist classifieds.

Steve in SLO

Martin,
Lowering the car with the PSS-9s, it is easy to get LOTS of negative camber so the insides of the tires wear out fast, but from what I understand, standing up the tires past a certain point is not possible due to clearance issues (?swaybar droplinks I think?). The last camber was set at -1.5, which was the least negative he could get it. For comparison, stock setup is -1 and RS is -1.2. I drive hard and still had the inside cords showing when the outside if the tires were not yet to the wearbars. Part of my problem may be that the tires are riding along the inside edge of the tread until they get worn down enough to have a larger weighted contact patch.

Steve Weiner-Rennsport Systems

Hi Steve:

Viken is right on target here,....

I too, always change all 4 tires when the car needs new ones since I've experienced the very same thing many times.

Install a pair of matching fronts and you'll be a happy man, (once again).

993Widebody

Viken, thanks for the condescending tone... I am definitely not the best driver in the group, but considering I am in group 3, where 90% of the drivers had track tires and some serious upgrades (Barber Motorsports Park), I am able to hold my own. Essentially I am in the upper middle of the pack, which means that I am pushing my car.

Have you put SO3s on your 993 and taken it to the track? If not, I suggest you stick a sock in it. If so, then I take that back. Like I said, I was surprised that the tires did as well as the P-Zeros, but hey, I am a believer.
FWIW, I met another 993 track junkie that swears the SO3s are BETTER than the P-Zeros. He is in group 4 and usually uses his track tires, but said he has had both of those street tires on the track and couldn't believe I thought the P-Zeros were as good.

And yes, I put new P-Zeros on the rears with about 10k miles on the fronts and the car handled great.

Viken

Sorry if I came across as condescending. It wasn't intentional.

You should have kept it to yourself to begin with. Unlike others on these forums, I don't post stuff based on what I read or based on what others say. If I don't have personal experience with something, I keep my mouth shut. Or, stick a sock in it, as you put it. There just is way too much misinformation going on here for me to stand back and watch. BTW, by "others" I don't necessarily mean you. So, don't get all that excited again.

Good for you and Bridgestone. Someone needs to keep their profits up.

Great, another track junkie. BTW, what is the definition of a track junkie?

I don't believe anyone is talking about handling here. The original poster was concerned about body wiggle or rear end stability in a straight line. Some call it tread squirm.

993Widebody

I agree, there is way too much mis-information here. That is why I am posting on my experiences, not what we "think" based on factors, such as tread life, etc...

I think you know what I mean by track junkie. Fully setup car, trailer, 5-10 track events per year, possibly some club racing as well.

Also, the poster originally stated that his car was unstable just driving straight, at reasonable speeds. I don't see his problem coming from used front tires, as a wiggly rear end on dry pavement at highway speeds sounds like there is a bigger problem. Possibly mis-matched tires front to rear or a suspension problem. Again, this is my opinion, don't get sooo upset if it isn't your opinion.

Why should I have kept it to myself to begin with? How do I know you do your own personal testing of every product you comment on? When have you made that public? I've been reading these forums for a long time and I haven't seen you state that. Maybe you should put it in your sig.

Bottom line is you are still being very condescending and authoratative in your tone, and it is not appreciated. For some reason you do not like bridgestone, and god forbid someone else does. This is the last time I am responding to this thread, so unless you want to PM me, don't refute anything that you expect a response to. I have better things to do than to waste my time defending myself simply because I liked the SO3s as much as the P-Zeros.

Sloth

Just to throw in my $.02... I have noticed the same thing with S03's, albeit in a 996 C2. It was so bad at one point that I pulled over to look for a cut tire or something loose. FWIW, all four tires were replaced at the same time. I can not give an update to the wiggle as I have since traded it.

ApexL8

I hate to jump in here when it is getting all heated up, but I have been a Bridgestone fan for a while, running S-02s and S-03s, and the N (Porsche) variety on different vehicles. The Bridgestones are a good performer, but they have a problem with "tramlining", they follow expansion joints, and they are squirrely on grooved pavement.

Steve in SLO, where are you running these tires, on Highway 101 around SLO? Is that grooved concrete there? Do you notice any difference between the car's behavior on asphalt and grooved concrete?

Take a blast down Pozo Road and see how the tires take it (love that road!).

By all means if you can swap out tires and see if the condition changes (as suggested) at least you can pinpoint the problem to the tires then, and eliminate your suspension setup as the problem.

Am I really missing out having never tried these street Pirellis? Are they just the cat's meow, or what?

Tire Rack Consumer Surveys

FWIW I have nothing against Pirelli, I have their PZero Corsas for my track tires, fun when it is dry, but in the rain freaking scary. I would rather run Bridgestone street tires in the rain at Road Atlanta than those Pirellis, having done both. I too am not the fastest driver in the world, just moved to Group 4, so basically a faster Group 3 guy, so I'm no Mario Andretti, but I'm not putting around at 3/10ths either, I can use just about all the tire I'm given. Please don't let these comments lead to a protracted discussion on street vs. track tires, they're just my observations about these particular kinds.

I would LOVE to be a tire tester and do back to back comparisons! Is there a better job, maybe fighter pilot?

Best to all, play nice...donning Nomex,

Viken

I would hardly call a guy who sees the track 5 to 10 times a year a track junkie.

I never said I don't like Bridgestone. In fact, I have the S-02A on one of my cars and love it. It just so happens that I have experience with the older S-02 and the S-03PP and I feel they are both inferior to most other maximum performance tires. The latter even more so than the former.

And, in this instance, the reason I don't like the S-03PP, as clearly stated earlier in this thread, is that it is an inferior product in the "Maximum Performance" category as applied to "Rear Engine Sports Cars" in every example I have driven and tested. Its not just for some random reason. Please read my posts again.

If you want to continue to use and support an inferior product, by all means go ahead. But don't expect those who know more through real testing and measurement to stand idly by and watch you or any other poster spread misinformation and misguided recommendations to the unsuspecting novice here.

Steve in SLO

There is definitely more bad behavior on grooved concrete, but they got SCARY on 101 in asphalt areas without grooves when the ambient temp was over 95, leading me to think some if this is contact patch related. I am sure the deep grooves and soft rubber also played into it.
Re: Pozo: I have driven about every road in that area, and love them all. The back end sways quite a bit in transition until the car is fully set in a corner.

Robert Henriksen

Someone with mAd sKilZ?