Cal Club Autocross Forums

Hi All,
Time to pick up a new set of tires. My current set of Potenzas will not last another event weekend.

Sooo, with credit card in hand, I am on the prowl for a set of rubber.

These tires will be going onto the Honda S2000, which is running in the BS Class. I am considering getting tires that I will use only for events and augment with another set for every day driving. This partially owing to the fact that I prefer to have a set of tires in good shape to go to work in on Mondays, as well as getting some tires that are more track oriented.
I will be mounting the tires to OEM wheels...

If anyone has experience with the best tires for Solo events, please let me know. I don't want to spend too much, and I would like a tire that will last 6 events or more. Plus, I really want to stay in my current class and maybe even be competitive.

So far, I am looking at these:
Direzza Sport Z1 Star Spec
http://www.tirerack.com/tires/tires.jsp ... toModClar=

and these
Kumho Ecsta XS
http://www.tirerack.com/tires/tires.jsp ... toModClar=

I have never run the Dunlops, I like my XS (on a Corvette) but they are soft. I have run a couple of practices with them this year and have a couple of thousand street miles. Don't know if they would go a full season of practices and competitions? So far have only run them at Auto Club so not sure how they will handle El Toro. I have been spoiled by R-Comps but once I got the pressure right on the XS 35 front, 32 rear, they hook up very well and are predictable.

Now if you were to get a second set of wheels, maybe some R-Comps, a couple of mods and come over to BSP.

I just won the SK1 index class at last weekend's event in a BS-prepped S2000 on the Dunlops -- I have not tried the Kumho XS, so I can't comment there. The Dunlop is actually a nice street tire as well -- that's what I drive on. I considered the Hankook RS-3 since it is supposed to deal well with heat, but the folks who run them say that they really need a wide wheel and lots of negative camber to work well. The Kumhos are also supposed to be good when it's hot, not so good when it's cold.

Note: I am using 225/45-17 on the front wheels and 255/40-17 on the rear wheels.

Grassroots motorsports a test of all of these tires in 2009. The Bridgestones beat the Dunlops, and the Kumho's topped the group. Falkens were the baseline. You can read the results here http://grassrootsmotorsports.com/articl ... es-part-1/" onclick="window.open(this.href);return false; the test vehicle was a Civic.

Are you running the National Tour or Pro? I got a great deal on my Kumho XS last year because a couple of the guys were selling thier winning Kumho bucks. Got the tires at the usual Tire Rack discount, plus $.75 cents on the dollar for the Kumho bucks.

I would go with the Dunlop in your situation. Good daily driver tire, good in the wet, good in the dry, works well on stock cars and lasts a long time.

Dunflops are my daily driver tire on the 335 coupe. Really really love them.

One thing to note in the GRM comparison is that the size of the Dunlop was taller than any of the other models, and as they said it killed their gearing. That's not going to be an issue with the S2000.

Interesting difference between GRM's results with the Kumho, and the Tire Rack's test results published on their web site. The Kumhos are said to need heat to work. Maybe I should try the Kumho next time, if any of these tires are still around by then.

The Dunlops are wonderful at the limit ... very progressive ... very confident inspiring

+1 on the Star Specs. I'm running on the RS-3 now, and I really like them, but it's looking like they don't wear nearly as well as the Dunlops. It sounds like that's a significant factor in your decision. I had a set of Star Specs and really liked them, and they lasted an entire season.

John Stimson wrote:One thing to note in the GRM comparison is that the size of the Dunlop was taller than any of the other models, and as they said it killed their gearing. That's not going to be an issue with the S2000.

Interesting difference between GRM's results with the Kumho, and the Tire Rack's test results published on their web site. The Kumhos are said to need heat to work. Maybe I should try the Kumho next time, if any of these tires are still around by then.

If the test car was a civic, they are pretty darn sensitive to tire diameter.

GRM's test car was an ST Civic.

John Stimson wrote:GRM's test car was an ST Civic.

Isnt that what we all compare to as the "Gold" standard? (/duck)

John Stimson wrote:One thing to note in the GRM comparison is that the size of the Dunlop was taller than any of the other models, and as they said it killed their gearing. That's not going to be an issue with the S2000.

Interesting difference between GRM's results with the Kumho, and the Tire Rack's test results published on their web site. The Kumhos are said to need heat to work. Maybe I should try the Kumho next time, if any of these tires are still around by then.

I am hardly a tire expert, I don't think the XS are bad cold, they are pressure sensitive. I have heard they are lousy in the wet, that hasn't really been my experience in our limited rain.

Hard to argue with Dunlop, the people that run them love them.

Arthur ... exchange rides with people on practice days. Let folks do a lap in your car so you can do a lap in theirs ... to get more experience in other types of cars and different types of tires

Byron Goodman
Plus, I really want to stay in my current class and maybe even be competitive

I'm not sure how competitive you can be against similar cars that are on 710's or A6's. Running a street tire in BS likely won't get you there.

A BS S2000 on Dunlops can dominate SK1 though - just look at John at the last event. He was untouchable.

These tires will be going onto the Honda S2000, which is running in the BS Class.

Maybe I misunderstood. SK1 with a BS index?

Steve Towers wrote:

These tires will be going onto the Honda S2000, which is running in the BS Class.

Maybe I misunderstood. SK1 with a BS index?

He may not know it (yet), but that is where he should run locally.

To elaborate on Max's last statement:

Hi Byron, we met on the grid at the practice. I had the white S2000. Steve's observation that the Hoosier A6 and Kumho V710 are dominant tires in BS is accurate. Using those tires also carries a near-requirement of running a much stiffer front swaybar, to prevent spinning the inside rear wheel due to the extra lean that the tires cause.

However, CSCC and San Diego both offer two street tire classes for cars set up under the Stock category rules, SK2 for lower powered cars and SK1 for higher powered cars. I highly recommend getting street tires (such as we are discussing in this thread) and running in SK1, whether you're just starting out or a veteran who is tired of paying for short-lived DOT-R tires.

Mako to wrote:Arthur ... exchange rides with people on practice days. Let folks do a lap in your car so you can do a lap in theirs ... to get more experience in other types of cars and different types of tires

As you know I frequently offer to let people drive my car, I am a little cautious about driving others as I don't want to be responsible for damage.

Thanks everyone for all the really good advice!

I am new to this, so getting to know some of these details will take me a bit of time....

I hope to have new tires mounted and ready in time for El Toro!