Planet 9

I've been searching the site to see what is new wrt to R-Comp tires for 2009 and I'm not seeing anything. Same with the TireRack site. So hopefully I don't get flamed for asking my questions here.

I have a 2007 CS, PASM, Sport Chrono, 19" Turbo look wheels. It is stock. I drive it 1 highway hour to the track, 3.5hrs on the track, and 1 highway hour home each day I lap. It rarely gets any other driving. I hope to do 20-25 lapping days this season. I've been through 3 sets of the Bridgestone OEM N-Spec tires in 12,000miles and want to move up to an R-Comp tire. What are my choices if I want a OEM sized 19" tire that I can use even if it is damp?

If I have to I'll get some 18" OEM CS rims for the track and keep the 19" OEM rims shod with something for wet days. If I go that route what are my choices in 18" OEM sizes for a DOT legal R-comp tires that can handle dry/damp conditions? Is there a choice that is not heat cycle dependant like the Michelin Sport Cup is? My typical day would be 6-7 session on the track.

Thanks all!

Chris

I think the Michelin Cups would work well for your application, but you can contact jim@tirerack on this site for his advice. He should know about the latest R-comp options; at least those carried by Tire Rack.

Michelin now makes a Sport Cup in 19" that's the proper size - 265/35-19 - it was made for the rear-tire application for the new BMW M3s. That's really your only choice in 19" right now as far as I know. They also are expensive - the MPSC in 19" are $333 for the fronts and $422 for the rears... that's a lot of money for tires you're going to chew through quickly.

Tires for 18" wheels are much less expensive, but you'll have to do the math yourself to see if going the extra set of wheels + the tires will work for you, but one set of 19" MPSCs will be $1500, about the price I've seen very nice 18" take-offs go for.

I switched from MPSCs to Nitto NT-01s this year in 18" size, - 245/40 and 275/40 - and have an extra set of wheels. The Nittos are about $900/set.

BTW, all R-comp tires are very effected by heat cycles, just like the MPSCs.

brad

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22-year PCA Member
PCA DE Instructor

As Jim mentioned, the michelin SC's are a very good tire for what you want to do--lapping days and the ability to use the tire to drive to and from the track, as long as it doesn't get too wet. I'm not sure how your local CMP would feel about driving --say--Kumho V710's on the street to your track.

the SCs have the stock 19" sizes to fit cayman, but the 18" rear size is a bit short; however, more than a few people on this board have used that size anyway with good results.

The idea of using a separate set of wheels for dry and wet tracks makes a lot of
sense to me. I haven't moved to a R compound, but use GY F1 Asy for street/wet track duty and Kumho XS for dry tracks on separate sets--all in 18" sizes.

Just a heads up for you. Caymans and Boxters have a vent tube that fills with oil at high G loads allowing oil to get sucked into the cylinders. There is a warning in the manual not to put R tires on these cars because of this. There is a post from one Cayman S driver who got black flagged for smoke. Track steward told him his engine was going to blow and wouldn't let him out. There is a gizmo for curing this problem available and it will be the first thing that goes on my new used Cayman when I buy it this year. I'd really suggest you look at the forum entry about blowing smoke with the red letters. Good reading.

The question about driving home with DOT R tires on the car is easy to answer. I routinely drive 300 or so miles home from the track on mine. I've done it with cord showing on the tires and I've done it in the rain. You have to keep both hands on the wheel because the car is a little more lively with these tires. In the rain, you can get some hydroplaning so just take it easy on turns and drive like a normal person in a normal car and you'll be fine. The R compound sticks very well to pavement. Lack of tread makes hydroplaning a risk but the better compound will really grab when you get past the water.

A word of warning... If you set wheel camber to make the car corner really well, you have to set the toe-in at near zero. Otherwise, the tires will wear out very quickly on the INSIDE of the tread.

Next, I'll add that I've run through 2 sets of Nitto NT-01s on my M3 and they are fabulous. They are more comfortable to drive on the street than any other R tire I've tried and tread noise is not excessive like the Yokos with giant tread pattern. They also ride decently. Dealer told me he sells them to Corvette guys who use them as their weekend street tires.

Is there a site sponsor who carries the Nitto? I need to ship to Canada.

Thanks

Where do you get the Kuhmo tires?

Ah... Me again. Just thought of another thing.

I would get a set of 18" wheels if I were going tracking this summer (R tires in 18 beat street tires in 19 any day and having a choice of tires rather than being stuck with only one brand is infinitely better) The cost of the wheels will easily be covered by the time you've bought 2 or 3 sets of R tires. In fact, just buy some used ones. They get crudded up and covered in tire clag pretty quickly. 19" fashion goes by the wayside at most of the track weekends I've attended. Drive well, go fast, play nice and you are OK.

I recently saw a guy with a TRAILER HITCH on his Cayman S at Putnam Park in Indiana. He pulls a little two wheeled trailer that holds a set of wheels/tires and a tool-box. Says he can hardly tell the trailer is on when he's pulling it. The hitch mounted where his license plate used to be. He mounts his car plate on the trailer. When he gets done with track stuff, he just mounts the license plate back on the car and the plate covers the square hole for the trailer hitch.

I must admit it was strange to see a Cayman S rocketing around the track with a trailer ball sticking out of its rear end, but it seems to be working well for him. He was very quick. Only the race prepped Vipers were quicker, That set-up started me on the hunt for a Cayman S of my own.

This tire trailer idea may seem like sacrelige to many of you, but it's a nice solution to the tow vehicle problem and it keeps the dirty tool boxes and tires away from the interior of the car. I'm strongly contemplating this setup for my car as well. I stubbornly refuse to trailer my car to and from the track.

Check w/ tire rack on the new Yokohama Advan Neova AD08 - 19" sizes will be out around May 1st.Has a 180 TW rating.

I buy mine from Discount Tire Direct, Tirerack doesn't carry them. Don't know if they ship to Canada.

TR has the Kumho XS in 245/35/18 and 275/35/18 sizes which will work on a 987. They do grip and have some wet weather capability.

Regarding the blowing smoke at the track, I've seen a few Caymans doing this with PS2's and some with SC's that don't do it (not sure if their owner had a fix put in).

The warning in the manual states you should not use "racing tires" and more specifically, "slicks" - it does not mention R-compound tires with tread at all.

brad

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22-year PCA Member
PCA DE Instructor

I get mine from Discount Tire direct, as well. Look them up on the Web and see if they ship to Canada - I have them send the tires to my usual mounting/balancing shop (which is a Tire Rack installer) and it works out great.

brad

__________________
22-year PCA Member
PCA DE Instructor

Chris:

I am by no means as knowledgeable as some of the other posters here, but I was at Roebling Roads for a DE earlier this month and there were several GT3"s fitted with Toyo Proxies R888's and the drivers loved them; plus they drive back and forth to the track on them. Bob Woodman Tires in Bluffton, SC handles them and they do have a website, which I believe is Bob Woodman Tires Don't know if they ship though, but the guys there are very knowledgeable.

As far as the tire trailer there were two cars there, a Cayman S and a Carrera, both using the rear tow hook as the base to which you can mount a ball. Seemed to work very well; and the Cayman was from Sarasota, which is almost 400 miles. I am planning to do this myself in the very near future.

Good luck!

Gil Frank

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Gil Frank
2008 Cayman S Guards Red, PASM, Sport Chrono, Sport Seats w/painted seat backs, Sport Exhaust, Sport Shifter, Fire Extinguisher, Bi-xenons, Clear Bra