Marv.Frazier

Remember to keep your tire pressure visible on your display - is helpful to track pressures during your track session, see when tires get warm etc. I typically see a 6-8 psi increase during each session running factory tires (until i wear them out). Spring temp was ~55-60 at the Apr DE at Mid OH. Running pressures of 29/34 cold.

hlee1169

I usually keeps 3 psi difference between front and rear, and I try to keep the rear from going over 40, so it's 35/38 HOT for me. I measured the pressure immediately right after I got off the track.

chuck911

Yeah that's what I was getting at! Because used hard those tires would look completely different. The edges of the tread blocks would be rounded and ragged, with chunks missing and gobs of rubber and crud stuck on here and there. Even if you drove a thousand miles after a good hard track day the ragged edges would still show. A picture tells quite a story to an educated eye, see?

Of course if and when you get "comfortable" enough (which really means skilled enough) to really work your tires you sure won't be getting anywhere near 13 DE days out of them!

But the real reason I brought this up was because the thread seems to be about how PDCC helps even out tire wear on the track, which in my mind "on the track" translates into "when driven real hard" yet these tires clearly have not ever been driven hard! This matters because its only under hard braking and acceleration that suspensions get loaded enough for the true wear effects of PDCC to begin to show. That's not to say you're not driving fast. I'm sure your speeds would give most people a heart attack if done on the street. But fast as that is its nowhere near what it takes to really put heat and wear into the tires. As you can see just looking at yours.

Also the "greasy" comment. Some tires do get this way because when heated up enough the compound softens and rather than improving grip it seems to just want to slide around more. This clearly is not happening in your case however, as tires run like this would show all the hard wear signs already mentioned, which yours do not. Most likely what you're calling "greasy" is really just the effect of running excessively high tire pressure, ie above 40 psi. As the tires heat up so does the air inside, raising pressure, which beyond a certain point actually decreases grip, often times by a lot, leading to a feeling of running on marbles. When this happens handling feels initially very precise, because the high pressure is making the tires respond very fast, but the car also slides around a lot more because the contact patch is reduced by the excessive pressure.

Does that pretty well describe how your car feels?

holminator

Not sure I would use Pilots or P-0s (or any street tire) on the track, but Pilots are perfect for the Autobahn. P-0s are perfect as sale items on eBay. Apples and oranges both taste good, but don't choke on the seeds.

MayorAdamWest

So what would you use? Not many options that don't break the bank. Even R888's in 19 will cost 300 or so per day at the track. MPSS's are closer to 100, depending on how you drive.

chuckbdc

Tires, brake pads and fuel are consumables. You can cut costs by buying less expensive grades and brands.

PSS are better that most for the track and everywhere else (other than snow), particularly if you plan to drive there and back home.

Re Pirelli P Zero: mine have been just fine for normal street use, including rain and cold weather, and are just over half worn, bit less front and bit more rear after 13 months and 13k miles. Of course, based on viewing F1 last season and this, I check them carefully after every 4th trip to the mall.

hlee1169

It is true that I was not pushing the tires to the limit, but my point is that rear tires on 911's usually wears out from inner edge first, even from aggressive street driving, and I think my track use could be counted as aggressive street driving. When I had the 997.1 and the 997.2, the rear tires on them did not make it past 15K miles, and that was all street driving. I have 13K miles on the 991, and the wear seems even across the tread, so I attributed that to PDCC's side benefit.

Yup, you are spot on, I checked the tire pressure after I was sliding around a lot and slower and they were in the 40's. I strived to stay below 38psi for rear, and 35 for front, and they were better. Still, I am wondering if a 20 min session is the maximum time these tires could take if a more skilled driver was pushing them to the limit.

Cogito_Ergo_Zoom

Out with the old, in with the new...

Also got a chance to get a closer look at my discs and pads while the car was up on the rack. Rear discs and pads are wearing at a somewhat surprising rate, faster than even the fronts. This has to be down the effects of PTV, of course.

Cogito_Ergo_Zoom

Bonus RS Clone photo. Final tuning being done on high-butterfly 3.3. What a sound!

fester

Any idea what Wt Dist is for 4/4S? It should be more even.

holminator

I was just messin' with ya. Ignore me.


None of us have much in the way of choice yet.