You guys that have switched from PS2 to PSS...did you notice any difference in performance and higher speeds?? I'm getting noticeably/freaky amount of wandering around as speeds approach 100. The car used to be very comfortable at 120. Now at 105 it starts to feel a little sketchy, any little gust of wind moves the car around, it seems to track in the grooves, even the subtle high speed highway grooves. It's a little unsettling. I can't imagine running it up to 130, let alone higher!

NOW...here's the hard thing to pin down...at the same time I got the new tires, I got new wider offset Forgestar CF10's and lowered the car on H&R sport springs. So some geometry certainly changed....yes, I had an alignment. .04 toe in each side front, .17 toe in each side rear. I've got about 220 miles on the setup. Temps have been cool to mild here in KC, so I haven't got a lot of heat in them yet, but not bad.

Anyway, the PSS are quite a bit softer on the sidewall. You can literally wiggle the car around on the tread blocks and sidewalls like my Jeep! So this has to be some of it? For reference, this is my first set of new tires for this car, I had been driving it on the PS2's that came on it 15 months ago. The rears were 2012 date, the fronts were 2009 probably OEM? Car only had 12k miles when I bought it. So they were harder, near slicks in the rear, the car felt more planted and solid in the front at speed. Now it's the sensation of air getting under the car or lighter steering.

I'm going to throw the old PS2's back on and see how it feels. Everything else about the PSS I love! And I hear guys tracking these tires on GT3's, etc. The grip like mad even in cold, but they do have more of an all season tire feel and flex to them. I really like them up to about 90...then it starts getting weird. Bottom line...whatever the cause, springs or tires, it's getting changed.

Thanks for any input or experience!!

 

I think you are experiencing the difference between N rated and non-N rated tires. PSS's are probably more comfortable for normal driving and last longer but do not behave the way Porsche wants them to at high speeds on their cars even if they have the high speed ratings.

 

I think you have in large part answered your own question...

..depends how you track your car but most track rats with high HP cars would not say the PSS is a track worthy tire. 997 and 991 GT3's tracking Michelins would unlikely be tracking a PSS.

 

Interesting. I am in the garage now mounting up the old PS2.

With PS2 getting hard to find what's the option? Cup 2? I'm guessing they are stiff sidewall?

I suppose if your track had one straight that was 120 mph and everything else well below then these PSS would be awesome. They grip like mad!

 

MPSS's here. I'm lowered on Damptronics, corner balanced, more negative camber, Techart rear wing, GT3Tek sides and front. I've had it up to 140 mph in a 5th gear straight away and it's stable as can be, no wandering whatsoever. Perhaps it's more of an aerodynamic thing for you...

 

THIS is what it feels like, lighter front end, like air is getting under the car, that's the sensation.

 

Try again with the PS2's. You do not have a baseline comparison when lowered only.

 

Just returned from test drive. Absolutely the tires!! Car was RAILING and planted just as before,120 was rock solid like before.

FOR SALE : PSS 305 30 19, 235 35 19...less than 300 miles. Local pick up in KC preferred.

 

I would think depend on the highway, my PSS are extremely stable at highspeed on George Bush Turnpike but lousy on Loop 635. Yesterday was windy, at 110mph on 635 hwy was bit edgy. Noticeable gain in stability since the addition of the GT3 wing matched the front bumper. I know the stock wing do little at high speed on a windy day.

Even in rain, the PSS handles very well 80+.

 

Again, this IS my first rodeo with new tires and performance tires in general. This a fun/weekend car, I'd rather have the rock hard go kart feel over what the PSS is giving me. So if anyone has a recommendation over the PS2, or Cup 2 or any other brand that might be a more fun tire, I'm all ears! The sidewall stiffness of the PS2 is undeniable.

 

some break in time may be needed on the new tires...
http://www.tirerack.com/tires/tirete...e.jsp?techid=5

and
http://www.tirerack.com/tires/tirete....jsp?techid=47

 

I agree with the break in. On my previous 996 I had MPSS and they were great over 120 at DE's. I just mounted a new set on my Carrera Sport II's yesterday. Don't give up on them yet. Also think about getting your speed fix at a track......so much safer.

 

Thanks...ya not much track action around KC, as in NONE. We do plan to hit MAM this year when we can, but it's 2 hours away. I'm not cruising at that speed, just brief bursts out in the country...not to worry. Still, the fact a car with a top speed of 180+ (in theory at least) shouldn't be making you $hit your pants at 110 because it's loose feeling on it's tires. I'm going to keep running them a few more months before I decide. Still, the difference between the two back to back drives was unbelievable.

What other Michelin has a stiff sidewall like the PS2? Any of the cup tires? That quick side to side action is awesome...even better with the DSC unit!!

 

PSS are perfectly planted and safe, but certainly not with new still exuding rubber lubricants. No brand new tire will. They have been run in Porsches and Ferraris at high speed in closed circuits with stellar results.

 

Yes, I realize that, they come highly recommended from other 997 owners as well...that's why I went with them. Just telling you what I'm experiencing and trying to figure out why. If I didn't drive them back to back I'd think I'm crazy too. Not sure if others are running MORE toe in, I doubt it if they're tracking the car. It just has a very light steering feel with the PSS. Like it needs more aero, but it doesn't have that feel with the PS2.

I get the lubricant issue, but assumed that would be more of a factor in cornering...not high speed straight line. What I'm feeling has to do with sidewall stiffness. Sitting still in the garage you can move the PSS around like superball rubber under the car, wiggling around, you can clearly see the sidewall flexing easily. The PS2 do not do that. I understand the tread can harden off or cure, but the sidewalls are not going to get stiffer, correct?

Again, the PS2's I took off are old and hard, so they're transmitting a LOT of road feel. I like the road feel and stiffness.