turbodogs02

^^ thanks.

CyberGeorge

I have a bit of an issue here with The PS4S. Short story is I used these tires for a few sessions and they went down to the cord pretty quickly. I am just starting at the track, so I asked for advice. One of my instructors pointed me to this thread. I decided to get max camber up front and try them again. I had similar results. Details are below. Can someone provide some recommendations of next steps, please?

My 981 CS 2014 came with the P Zeros on 20" wheels. After about 23,000 miles, I took it to the track for the first time last year during an HPDE weekend with the local PCA club (St. Louis). After that I did a PDX with the SCCA this season. At that point it looked like it was time to change the tires because the thread depth was getting low. I ordered the PS4S and had them installed at the dealer. They also did an alignment. The before (stock) and after is shown below.

Before (this was stock):
Camber front: -0º44' left, -0º26' right
Camber rear: -1º33' left, -1º13' right

After (this was after the first change):
Camber front: -0º25' left, -0º24' right
Camber rear: -1º31' left, -1º12' right

I took it to another PDX (4 sessions) and then a PCA event. After 2 sessions at the PCA event (20 min and 30 min) I had this on the below on the right front tire. The rear right was about the same. The two left tires were getting there, but not down to the cord yet.




I asked around, read reviews on Tire Rack and everyone except from two reviews on tire rack is raving about these tires. The two reviews on tire rack that were negative were both from people that tracked their cars and both with very similar experiences as mine. Regardless, I couldn't find anything more suited to what I am doing (more track, little daily driving, no driving in rain, no driving in cold weather) and given the alignment did not have much negative camber, I decided to go with the same tire and a more aggressive alignment.

I asked the dealer to get me the most negative camber they could get and installed another brand new set of 4 PS4S. I ended up with the below alignment (this is with maxed out front camber):

Before:
Camber front: -0º27' left, -0º25' right
Camber rear: -1º30' left, -1º10' right

After:
Camber front: -1º09' left, -1º08' right
Camber rear: -1º35' left, -1º37' right

That was last Thursday. On Saturday I went to an SCCA PDX (3 sessions) followed by a practice time trial and a time trial session (each of these are 20 min). This time I was equipped with an accurate pressure gauge and was checking pressure immediately after and before each session. I would start at 29-30 cold and wouldn't go above 36 hot. In the previous set I had seen up to 41 hot. At the end of my last session, I had this issue on the right front:




I stopped the TT there and missed the following two sessions.

Obviously, I am not very experienced at the track. I haven't had a wheel out and I don't believe I am pushing this car to the limits that other drivers have the ability to do. I don't think that others change tires this often, though and I have not seen anything like this on the tires of the other drivers. Even my stock set was changed because of tread depth and not this chunking issue. I fixed the alignment as much as possible and I am being diligent about tire pressure. I give it at least an hour between runs to let the tires cool off. Temperatures during the last runs were pretty high here around 85 F. I am going to get with an instructor to see if I can fix anything on the way I'm driving, especially the left turns. The road course is 1.6 miles and my latest times were consistent between 1:13 and 1:14. Granted in the beginning (last year) I was not as aggressive as I am now (and I have no idea what my times were). However, I am certain there are others on the track that are much faster than me and they don't have these issues with the tires.

So, now, after a few weeks, it's time to change tires again for the third time. The only parameters that can still be adjusted are my driving and the type of tire. The options seem quite limited, if I want to stay with the stock size on 20" wheels: PS4S, PZ4 or the Trofeo R. Has anyone had any such experience with the PS4S or has any other suggestions? Not sure where to go from here.

Thank you and apologies for the long post.

Gofishracing

Your tires show serious signs of pushing through the turns- the extreme feathering and chunking from overheating due to driving style I fear. Any turn you go into that the car is pushing you have gone in too fast. auto cross 32 36 max hot from Michelin about Cups - use that as a guide. It might feel fast- pushing but it's not.Smooth is fast . control your corner entry so you can control your corner exit. Working with an Instructor a great idea as you are planning.

CyberGeorge

That makes sense. Thank you so much for taking the time. I will watch it and will get with an instructor in my next session.

Gofishracing

you run your hand across the front tires from inside to the outside on any track car it will give you a good indication of driving style. Tire pressures are easiest at DE level to work with rather than probe style or digital pyrometer. If you are sawing at the wheel similar. No video so just visual observation.. Smooth it out- get the flow- like sking- use all the track. Try going in later,. in slow- out fast. Talking tires are not really happy tires.

Mr. Turtles

CyberGeorge, I can say that my experience with the P4S is much much different. I bought a set for my 991S late last year when I thought I was getting my new GT3.2 early. Haha, it never arrived until track season was over so I used my P4S's for 6 full track days (4x20 min each day) at Mont Tremblant and Calabogie which are not easy on tires. I run in the Black run group and only have max camber for the car without any aftermarket parts and was nearly able to keep up with the guys on MSPC2's. As others will tell you the PS4's will run about 2-4 seconds behind the sticker MPSC2 which is pretty quick for a street tire. The wear you are getting as seen in your pictures sure looks like you are pushing through the corners way to hard. You mention your track being shorter and likely more of a technical track. Calabogie while longer than your home track has 21 turns and requires a lot of patience before getting on the gas. Tires can wear out very very quickly there even when you drive properly. The key is to get the car turned before getting back to full throttle. Definitely find someone with experience at the track your driving for advice on the tires and driving style. You should be able to get at least 20 sessions and more likely 24-30 from the PS4's.

CyberGeorge

Mr. Turtles

The Trofeo R are much stickier but would not be great in wet and thus more of a track tire with limited street duty. I've also heard good things about the Bridgestone RE71-R as a good track/street tire that may fit your car. They may also be better suited to your driving style but as you mentioned the key is to get instructor help. The cheapest way to improve and reduce consumables costs. Enjoy.

CyberGeorge

Mr. Turtles

Nitto NT01?

CyberGeorge

Looks like only the NT555 from Nitto are available. I may just buy a set of 19" wheels and use that for the track. Many more options there.

CosmosMpower

-1.3 is not enough negative camber, also are you overdriving into corners and using the sidewalls to slow the car?

Jake951

Agreed. You need much more negative camber for serious track driving. I have a 987.1 Cayman S and run -3 degrees in front and -2.5 degrees in the rear. I do have an aftermarket suspension setup that allows much more negative camber than stock.

daylorb

Interesting, I've had a very different experience on the PS4's on my Spyder. I've done a couple events at COTA, roughly 10 sessions of 25 minutes, plus a handful of sessions at my other local track and don't see nearly the wear on the PS4's. I tend to go into the heavy turns slower, although my times are not horrible. I'm braking at 200 foot market when others might brake at 150, so I'm clearly not pushing them crazy hard, but they have held up well. This is with stock camber.

I got a set of Nitto NT01's on some older 18" rims so I don't waste my DD tires, but have only run them one day so far on stock camber. Bottom line my PS4's have held up well and have plenty of street life left on them. Next step is to get some more camber.

CyberGeorge

My camber is maxed out and I don't want to make any suspension mods as I am certain I will trade in the car for a 718 GT4 (can't come soon enough). That said, it sounds like I am getting into the corners too fast, which is putting an excessive wear on these (or any) tires. My options for tires are either the same PS4S, the Pirelli PZ4 or the Trofeo R. The Nitto NT01, Cup 2 or RE-71R are not made in the 235/35ZR20 (front) and 265/35ZR20 (rear), unfortunately. I could get a set of 19" wheels and use some of the above, but considering I will be trading in this car and the hassle especially when traveling to a track further from my location it's probably an issue.

From everything that everyone said, as much as I hate to do so, I'll probably have to get the PS4S for a third time and get in with an instructor, describe my issue and watch the turns. Being that I just started tracking (compared to some other folks), I don't have a very good feel of how much I'm really pushing through the turns compared to others. I also don't have any way of knowing how fast I go around the track. I've used some apps (Track Addict and Lap Timer), but they seem to be erratic. The TT event I participated in gave me some indication, but it won't happen again on this track for a while. So, the instructor and watching the entry speed in the turns seems like the next move at this point. Thank you for all the advice!