Rookie tire question

[oregonduckman]

During the pm runs on Sunday the Michelin Pilots on my Cayman became very hot and greasy. Someone suggested I try the Yokohama Advan Sports since they may hold up better in the heat and also go to a wider front tire to help with the Cayman's tendency to understeer using the factory alignment and tire width.

Any advice on this subject would be appreciated.


Thanks,

FAST UPS

[mrondeau]

I would suggest getting an AX alignment at Dieters or Black Forest to correct the understeer. As for the tires, I've found that the Michelen Pilot Sports work well at about 38 to 40 psi. They are not the best tire, but they do work well. The biggest problem with them is that they are very expensive. The Bridgestone Potenzas and Yoko Advans are less expensive and seem to grip a little better than the Michelins. Just my $.02

[Steve Grosekemper]

You don't say what your pressures were when you came off the track.
You may have just gotten the starting pressures to high.

Be sure to monitor this at the next event.
A tire gauge is much cheaper than tires...
BTW- My RA-1's did the same thing, I just didn't have anyone to bleed them off between runs.

[UKAYMAN]

I agree with the above totally, keeping an eye on the pressures is the way forward. I had to bleed out at least 2-3psi after each session back down to 38psi(HOT). That was a first for me at these events, and I think most people found it greasy out there too. I certainly did!

As for tires, i'm running with Falken Azenis RT-615 (I think we've had this discussion before) and another good street stock qualifying tire is the Yokohama Neovas. I have heard they like heat better than the Falkens but then they cost twice as much, close to the Michelins price the last time I checked.

I use my original wheels with the PS2s for everyday driving and the Falkens for AX, which in theory helps save on total cost in the long run. I have run 7 AX events with the Falkens and they have worn very well. My PS2s look like new, and my car has covered over 12,000miles in the 8 months of ownership.

If you don't want to keep incurring the high cost of replacement of the PS2s and potential risk of damaging your nice 18" Cayman S wheels from the crumbling Qualcomm surface, i'd invest in a 2nd set of wheels and cheaper tires. Thats my best advice to you, which proved my situation correct as a big piece of tarmac was thrown up from my front tire, hit the rear mud flap ripping it off, and bouncing off of my rear rim. Thankfully the mudflap can be replaced cheaply, and my AX rim is just scratched, but my originals are saved.

I do have a 2nd set of AX wheels. PM me if you're interested as I'll let them go for cheap, they are just sitting in my apartment taking up space.

Thats my 2p input (i.e. worth about $0.04)

[mrondeau]

Thats my 2p input (i.e. worth about $0.04)

Inflation!!

[LUCKY DAVE]

For some reason it did seem very slippery on Sunday. My rears were occasionally spinning up on corner exits, and I'm running a not-super-powerful car on 888's. I bet the GT-3's required precision throttle control....
The hot sunshine (high track surface temps) can play havok with grip.

[Irksome]

I agree, it seemed to get slippery/slower in the afternoon. I usually get progressively faster on timed runs, and I was getting slower. Of course, I had 6 runs, as timing issues forced me to re-run my first two timed runs. I think my tires got to ideal temp and then started to melt!

My recommendations to you (having recently traveled this path myself!) are (in order):
- Slow in, fast out
- Closely monitor/manage tire pressure between laps
- Alignment
- AX wheels/tires/spacers

When I started out, I was convinced my car was set up wrong. Then I got more instruction and focused on straight-line braking and hitting the correct entry speeds, and suddenly my car was much better! Cheapest upgrade ever = better technique. I would suggest you get an instructor known for good braking and see how they do it (Ted Drcar opened my eyes).

Tire pressure is the next thing I would suggest, just keep a gauge handy and jump out between runs to check and bleed. I think I bled out almost 8 pounds over the day on Sunday. You should also try a few different pressure levels, the 'ideal' pressure seems to vary by driver and car.

Alignment definitely makes a difference. I tried 4 setups before settling on one, and I'm pretty happy now. This is my daily driver, so I didn't want to mess too hard with toe settings, but I went very aggressive on camber and it made a big difference. I got my current alignment done at Black Forest (they are 4 minutes from my office), but there are many that can do that. Just be sure to pick a shop that is familiar both with Porsche and autocross/track setups.

Tires definitely make a difference, but I put it last because what's good for AX may not be right for street, and vice versa. I bought a second set of wheels after destroying a couple sets of expensive PS2s. If you decide to head down that road, there are lots of options. Right now it seems like the best bang for buck street tires are the Dunlop Direzza Sport Z1 Star Spec (say that three times fast!) and the Falken Azenis RT-615. I got my Azenis RT-615 set for under $800 delivered to my door (by comparison, PS2s are $1300, and Advan AD07s are $1400). And, if you are heading down this slippery slope, you can look at alternative wheel and tire sizing, and even spacers to get a wider stance.

Tom Meissner

[UKAYMAN]

I have been reading a bit about the Dunlop Direzza Sport Z1 Star Spec, but have yet to see anyone autocross with them. I guess they're quite new to the market. Maybe if the price is as cheap as the Falkens i'll try them next time.

[Irksome]

I heard about them after I purchased my Azenis, and did some research. TireRack recently did a 4-tire performance test that included the Dunlop, you can see it here:
http://www.tirerack.com/tires/tests/tes ... p?ttid=107

Unfortunately, while they test against the Yoko Advan Neova (a well-regarded AX tire), they didn't test against the Azenis (since TireRack doesn't sell Falken tires). But the results against the Advan are very good. I am considering buying the Dunlop when I finish shredding my Azenis. I have not yet seen anyone run them at an SDR AX, so I don't know if the test results match real-world results in our backyard.

I did some googling, and it seems like the Dunlop is getting some good press in the SCCA circles.

So, I nominate you to try them, and let us all know how they do!

[mrondeau]

I'm running the Bridgestone Potenza's for my AX tires and I really like them. They have a UTQG rating of 140 and they seem to wear well. They're also a lot of fun on the street. I would be interested to hear how the Dunlop's do. I think it would come down to cost for me.

I've noticed that tire pressure makes a tremendous difference in these tires. I also have a very aggressive alignment since this is not my daily driver. When I do drive on the street (which is quite often), I really enjoy the increased turn in and response.

[UKAYMAN]

Irksome

So, I nominate you to try them, and let us all know how they do!

Haha.. Okay next time i'll give them a go. Provided price fits my budget, and they have some usable sizes for Cayman fitments.

I do like the Azenis though. Its becoming quite good fun sliding the car around on them. I hear they are good for drifting too??

[Rooster]

The Dunlop Drizzle DZ-SuperStar A3 101 (I mock its long name) is a superb tire. If it comes in the right size for your application, it is the street tire to have. It will give you a measurable advantage over the Azenis, and for now the Dunlop is reasonably priced.

- Ted

[oregonduckman]

Do you happen to know if the Dunlops are N-Spec rated? Since my car is still under warranty I prefer to stick with Porsche approved tires.

Thanks

[Irksome]

They are definitely NOT N-rated. =)

The Pirelli Pzeros and Michelin Pilot Sport PS2s are probably the best N-rated tires available for autocrossing. I had the same trepidation about straying from the N-rating, but eventually became convinced after paying for a few replacement PS2s.

There are lots of debates about N-rating, and the value of it, and the risks of straying. You may want to search a bit on Rennlist, there have been some classic 'discussions' on this topic. I frequent the 996 board there, and it comes up about 2-3 times per year, and the threads usually run to 5+ pages.

[Kim Crosser]

My $0.02 - the BEST AX street tire for a Boxster/Cayman is the Yokohama ADVAN Neova AD07. I have run three sets now and they work great.
The Falken Azenis were ok, but they heated up quick and got real greasy. My best times were always on my first timed runs - by the third, I felt like I was in "Tokyo Drift" mode.
The Yokos wear well, ride ok on the street, and do not get greasy as they heat up - they just get stickier. My best times are usually on my 2nd or 3rd timed run, which is where I expect them.