Planet-9 Porsche Forum banner

1 - 20 of 26 Posts

·
Registered
Joined
·
2,747 Posts
Discussion Starter #1
I've had my Michelin Pilot Sport PS2 for about 2 years now and there's still life left in them, not down to the wear bars yet, and I'm wondering if I'm getting less traction out of them through the corners.

I would have thought the opposite would be true that less tread meant more traction. But the other day I took a corner pretty quickly and the whole car began a 4 wheel drift (no breaking, only very light acceleration) until the PSM kicked in and I thought, huh, are my tires losing traction?

Can the rubber's age affect it at all if they're only 24 months old.

:thanks:
 

·
Registered
Joined
·
6,829 Posts
Can the rubber's age affect it at all if they're only 24 months old.

:thanks:
Yes, it can - the continuous heat cycling and the environmental degradation makes the tire compound get harder over time. I've gotten rid of every set of my PS2s (four sets in 3.5 years) because they had heat-cycled out, long before all the tread had been used.

brad
 

·
Registered
Joined
·
1,397 Posts
Yes, it can - the continuous heat cycling and the environmental degradation makes the tire compound get harder over time. I've gotten rid of every set of my PS2s (four sets in 3.5 years) because they had heat-cycled out, long before all the tread had been used.

brad
Exactly; I've got a spare set of PS2's in the basement I could use on the street but for track use they're pretty much done after 1.5 seasons for DE use. IIRC, there are tools to test the durameter of the tire in order to judge how hard they've gotten.

When I took these off the track wheels, I replaced them with the PS2's that came with the car to get me through the season--big mistake. After 1 DE, they had less traction than the dedicated track tires. My guess is that the roughly 2 years worth of street use put enough heat cycles into them to essentially render them useless for track duty. Still had plenty of tread..
 

·
Registered
Joined
·
128 Posts
Yes, they do. It depends mostly on age, heat cycles and wear depth.

However you can "shave" brand new tires and get the best grip there is on dry surface = slick.
 

·
Caymaniac
Joined
·
5,658 Posts
People shave PS2's? You might as well with a street alignment because the edges cord through way before the tread. (if you are dedicating them as track tires.)

People shave PS2's? Hmmm....really?
 

·
Registered
Joined
·
911 Posts
Heat cycles aside - my PS2s wore out the outer edges. That's where I've noticed the loss of performance. That's after 7 track days.
 

·
Registered
Joined
·
433 Posts
Bizarrely, same happened to me. I never thought I'd have heat cycled my tires, with no track or auto-x so far, just a bit of spirit here and there. My rears had decent tread at 2.5 years and 17,500 miles, perhaps 5/32nds but very even, decent wear. I was waiting for them to get to 4/32nds, but I got tired of the car feeling so loose in the dry. So, on went a new pair of rears and yes I have rear grip again.

I wonder if this is a PS2 issue. I've also noticed that PS2's are more temperature sensitive than pretty much any other summer performance tire I've tried.
 

·
Registered
Joined
·
1,558 Posts
I'm not convinced that street tires heat-cycle out on track like R-comps and race slicks, but the rubber certainly deteriorates and hardens over time. I think of this effect as weathering (temperature swings, sun, rain, etc.) rather than heat-cycling.

I must be at the other end of the continuum from beez (4 sets of PS2s in 3.5 years), as I just ditched my OEM PS2s for a new set of RE-11s after 3.5 years. Yes, they had become noticeably less grippy than they were a year or so ago, but the rears were down to the wear bars anyway.

There was/is an old rumor to the effect that high performance summer tires are constructed with a harder compound near the wear bars, so they will wear slower toward the end. That was supposedly justified as a "safety" feature, but, if so, I guess sliding around more in the rain wasn't considered. The sidewall rubber seems to harden over time as well, which seems consistent with the time-in-service and weathering explanation.
 

·
Registered
Joined
·
6,829 Posts
I'm not convinced that street tires heat-cycle out on track like R-comps and race slicks, but the rubber certainly deteriorates and hardens over time. I think of this effect as weathering (temperature swings, sun, rain, etc.) rather than heat-cycling.

I must be at the other end of the continuum from beez (4 sets of PS2s in 3.5 years), as I just ditched my OEM PS2s for a new set of RE-11s after 3.5 years. Yes, they had become noticeably less grippy than they were a year or so ago, but the rears were down to the wear bars anyway.

There was/is an old rumor to the effect that high performance summer tires are constructed with a harder compound near the wear bars, so they will wear slower toward the end. That was supposedly justified as a "safety" feature, but, if so, I guess sliding around more in the rain wasn't considered. The sidewall rubber seems to harden over time as well, which seems consistent with the time-in-service and weathering explanation.
It will be interesting to see how my RE-11s compare to the PS2s over time, since I don't use the street tires as much as I used to...

brad
 

·
Registered
Joined
·
2,747 Posts
Discussion Starter #14
I'm not convinced that street tires heat-cycle out on track like R-comps and race slicks, but the rubber certainly deteriorates and hardens over time. I think of this effect as weathering (temperature swings, sun, rain, etc.) rather than heat-cycling.

I tend to agree with Jim. I don't have the track experience that all you guys have, but my gut tells me Michelin wouldn't produce a widely used consumer street tire that heat cycles that badly. It probably is just weathering.

Also the tires come off every winter and sit in a warm basement, don't know if that has any effect.
 

·
Boxster Enthusiast
Joined
·
1,733 Posts
My rear PS2s would always lose traction when they got near the wear bars. I drive 15K miles a year which is about how many miles I get from my rear tires.
 

·
Registered
Joined
·
196 Posts
Fascinating thread all. I just replaced my PS2s with RE-11s, primarily because I wanted to get two DE run days on 'sticky' tires before the snow falls, and am very excited to try them out on the track.

The outer edges of the PS2s were fairly worn on the fronts, although all four still had a little tread above the bars. Once the tires were off, I took a good look at them with the Porsche mechanic and at first glance I felt like I may have pulled the trigger on the PS2s a little early. He pointed out that all of the tires had small cracks running in between the tread grooves (weathering?). They also were very loud when driving and seemed overly firm (I bought the car used and the tread was about half gone at that time, so I didn't know how new tires would be). They were not too bad on the track after letting out a proper amount of air.

I've only got about 20 miles on the RE-11s, and my mechanic said that the chemical used to help release the tires from the mold would need to wear off before the tires would get sticky. My first attempt going around a corner fast did not go too well (not sure what happened, but it didn't hold the corner). They also don't seem as responsive as the PS2s, but again, only 20 miles so far.

Any thoughts?
 

·
Crusin worlds most isolated city
Joined
·
3,758 Posts
If the surface is not shinny anymore then you are good to go.
Now the trick is for the R specs to work correctly you must first get them HOT. Dont expect too much if they are warm or cold. Also different brand tyres will have different characteristics at different temperatures in this respect.
 

·
Registered
Joined
·
196 Posts
Thanks. Yea, the mechanic who installed them said 50 miles, but I read on another thread that it was 500 miles! I'd better get busy driving - the DE is less than three weeks away!:drivingskid:
 
1 - 20 of 26 Posts
Top