If those were my only choices I'd go with the PSS, but I haven't tried either yet. PSS is on my shopping list for street tire replacement.

For purely track day I might think about Bridgestone RE-11 (not the RE-11A), I haven't tried them on the Porsche yet, but I've liked them on previous cars. Now there's also the RE-71R which is supposed to be even better. Dunlop ZII aren't bad either, I do use them on the Cayman, for autocross and keep them on for the track. Now there's ZII Star Spec, which are supposed to be even better. That's not to mention the BFG Rival or its successor or the Hankook RS-3V2.

 

I've tried both and the MPSS gets my vote.

 

Micheln all the way. Just finishing my 2nd set of PSS and they are a great match for the Croc.

 

A friend with a 981 GTS saw some pretty severe chunking on the Goodyears. I have run the MPSS as a novice/ intermediate level driver on a 987.2 CR and thought they were good. My current favorites are the Yoko AD08R and the Hankook RS-3.

 

If your car is a new Cayman and Goodyear F1's come installed, which has been the case for many of us, go ahead and run them on the track. They are better than I feared based on published reports. In three track days I have found that they are not bad and are REALLY good in the wet. Having said this the replacement set will be MPSS.

 

They are better than I feared based on published reports. In three track days I have found that they are not bad and are REALLY good in the wet. Having said this the replacement set will be MPSS.

I don't have any track experience, but I can say that the Goodyears don't inspire confidence under spirited driving. Before I got my car, which came with Goodyears, I drove a Cayman with Pirellis and that car felt more glued to the road. However, I do agree that the wet performance of the Goodyear tire is pretty outstanding. At first I thought I was just imagining things but then I found this comparison here which supports exactly how I feel:

Monsters of Grip: Nine Summer-Performance Tires Tested Comparison Tests - Page 5 - Car and Driver

If you follow up on that, the Goodyear scores terrible in "roadholding" but then its wet performance is only barely worse than its dry performance. I also intend to upgrade to MPSS when it's time to change.

 

Yes, its new (2014) and came with Goodyear. I have run them a few times at the track and I am generally satisfied with the performance except that they tend to build up the air pressure way too quickly. After about 15min I have to pull in because I am up at 41psi (having started at 28psi). I am about to get a new set of shoes, but I am gun shy about switching to Michelins. I fear I won't like them as much.

 

Yes, its new (2014) and came with Goodyear. I have run them a few times at the track and I am generally satisfied with the performance except that they tend to build up the air pressure way too quickly. After about 15min I have to pull in because I am up at 41psi (having started at 28psi).

That's expected at the track, why do you think its a problem?

Tires will heat up when used, when used on track most tires I've run heat up to about 160°F, which adds about 10psi. The question is what the correct hot pressure, I found our stock Pirellis needed about 2psi less than spec when cold to be happy at about 38PSI hot.

Also I get the impression that the Pirellis are several seconds a lap slower than a good track tire (like the Dunlop ZII), but haven't done back to back testing to confirm. I'd expect the F1s to perform about the same the PSS to be quite a bit quicker. Not that lap time matters at a track day.

 

I would suggest you go AD08R or RE11. PSS are great street tires though

 

Or you can wait a little bit to see if the new RE-71R available in your size

 

It's a problem when I pay for a track day of say four 25min sessions and I am parking at 15min. Plus once I get to about 38psi the tires start to lose grip. I have heard the Michelins take longer to heat up which is a good thing for me, but I have also heard that some find the sidewalls too soft.

 

once I get to about 38psi the tires start to lose grip.

Then let out some air.

The other answers give a lot more detail about this. Finding the right tire pressures for any particular tire under track conditions is something you need to do.

 

Higher tire pressures at the track is a common, predictable phenomenon. Likewise you can't go by a starting initial pressure for all track days.

And you can ignore the Porsche recommended cold tire pressures on the track -- your cold starting pressures will be higher.

The experienced track day drivers will do two things:
1) fill the tires with nitrogen -- the humidity in air is what causes the most expansion in air-filled tires. Nitrogen is inert and completely dry.
B) monitor the tire tread temps, inside, middle, and outside -- after each lapping session to ensure they're as good (uniform) as they can get. This can be done with one of those hand held laser point/shoot thermometers.

Let some air out if the center and/or insides of the tread cross section are significantly hotter. 10 - 20 degrees+ is significant. Likewise if the center is markedly cooler then your pressures are too low and you're using only the tread edges (!) -- add air, then watch to see that the center doesn't start warming too much.

[If temps are uneven the hotter parts of the tire are in contact with the pavement, the cooler parts less so. You want the load equally spread inside-middle-outside. Ideally the temp should be the same: inside, middle and outside of the tread cross section. With negative camber this is hard to do as the insides will run hotter than the outside. Best I could do for my rears was a 10 degree F increase @ center vs outside, and 10 more inside versus center. I was able to manually adjust my front pressures to a pretty uniform temps inside-center-outside.]

Once you get the pressures stable you can then back off on the monitoring -- check your cold tire pressures and remember those values ... Start the next track day with those cold pressures.

Since tracks and pavement temps vary day to day -- even hour by hour -- the goal is to maintain best grip and contact patch by measuring tread cross section temps throughout the day. You'll have to check pressures as they rise, periodically letting air out when the center tread temps jump. Tread temps dictate tire pressure.

And after you drive home and the tires have cooled you'll likely need to add air back for street use since you were letting air out during the track day, right? So unless you have a set of track day wheels and tires, nitrogen fill isn't practical.

That hissing you hear in the pit is your fellow drivers adjusting their pressures. Take the time between lapping sessions to do the work or lose grip ("handling") and chew tires regardless of brand.

And if your pressures are as good as you can get them and your handling is still off, work on your driving ...

mmmv,
-PM.

 

The laser device is easy on the knees but not that accurate for differential comparisons across the tire. I have found in the past that the cool down lap and pit entry roads will equalize the tires surface temps to much for a good picture. A probe into the compound into is much better. Save the laser for rotor comparisons.

 

Given the choice the Pilot is much better, in fact the best that we have tested. Depending on the sizes you are running you may want to look at the new Bridgestone RE71R. In seeing the testing of this tire head to head against other Extreme Performance tires in both dry and wet they are going to be right at the top of the street/track tires.
If I can help let me know.

 

Thanks for everyone's input. Seems the consensus is that the Michelin is the way to go. Thus, I will give them a try. Thanks again.