New "ST" tire contender

[WD40]

Kuhmo XS
From the SCCA forums:

According to Rick Brennan, a 205/50-15 Kumho XS will be available as the only 15" size. Another size that may work for the EF Civic is a 215/45-16. I believe a 225/50-16 will also be made. There will be many sizes available in 17s and 18s as expected.

I spoke to a chief engineer and he tells me that the Falken RT-615 was the benchmark and that their test driver is consistently faster on the Kumho. Internally the tire has been known as the FK (Falken Killer). The test driver has also been faster on the new Kumho over the Bridgestone RE-01R.

If you're wondering why the one of the circumferential grooves is closer to the outside, it is for better rain performance without sacrificing dry grip.

Construction and design is finalized. Compound has yet to be finalized should be in orderly fashion to meet the April deadline. Cannot say whether all the sizes will be immediately available but time will tell.

Prices should be similar to Falken RT-615 prices which will represent a good deal for such a fast tire.
K-Mo

SEMA picture:


the Falken RT-615 was the benchmark
^^^Yeah...judging by the exact replica of the outside tread...
I'm just glad there's some more competition for a change!
(Never did get to see Nick's new Bridgestones in action...)

[fastneons]

the Falken RT-615 was the benchmark

That's good! That means it will still be .2-1.0 second slower than the bridgestone on a light car

If Kumho's test driver was using big cars (stx,stu), then they should have made the advan their benchmark. The Yoko, is that fast tire on those cars. It is more likely that they were using big cars (evo, sti, bmw), because of the sizes that are going to be available.

The bridgestone's are king of the hill on cars weighing 2400lbs or less, and the margin they put on the other tires is pretty remarkable for so-so drivers. The reason's I bought the Stone's are as follows:

1) FASTER!
2) Twice as many runs as the falkens. Because of this they are actually cheaper than the falkens.
3) $100 rebate

After running these tires, I beleive the compound is very close to that of an R-compound. They can be pushed extreemely hard, and will come right back. This really makes this tire much better than the Falken. When I ran falkens, I really liked them, until I tried to go a little to fast in a corner and overheated them, or it is over 90*. The rest of the run sucked! This trait really soured me on Falkens.

One more note on the stones', I hear sts pax is going to be changing quite a bit because of the speed pickup that national drivers are having with them! BAD new if you run in STS. REALLY BAD news if you aren't running bridgestones, or a new tire that is faster, Toyo(?), Kumho(?)! I guess we'll have to wait for someone to test them(not in a magazine, a real scca car, with a nat driver). Andy Hollis' test, and others, were a big factor in my decision.

[JoeE]

Those look good. That outer shoulder sure is simular to the falcons.

I need to get a tire sponsorship, those Yokos are freakin pricey.

[fastneons]

I need to get a tire sponsorship, those Yokos are freakin pricey.

No kidding! I think the last time I priced them, they were right at R-compound prices. They probably last a bit longer though.

[WD40]

The bridgestone's are king of the hill on cars weighing 2400lbs or less

So...
Where does that leave a 2,650-2,750lb car???

[fastneons]

So...
Where does that leave a 2,650-2,750lb car???

I would say overmatched in STS, but don't worry anyone who is not driving an 89 civic has the same problem.

2007 STS Nats results-14 trophies
12 = 89-91 civics, first 3 spots, 1 on kumho (2nd), 1 on falken(13th), all others on bridgestones
1 = 93 civic on bridgestones(4th)
1= 01 subaru on yoko's (9th, similar weight to Focus?)

It's really hard to compete with a car that can fit the widest tire for the class (225), and only weighs in the low, low, low 2000lb range. Even if they don't make the most hp, they probably have the best hp-to-weight ratio. Even more important in autocross, they definately have the best tire-to-weight ratio. Don't take this the wrong way. I really like the way the civic is classed, and I don't think there is any reason to move it. It probably is by far, the cheapest sts car to build. So, bang for the buck is very high, which is perfect for sts.

I would still say, that you would pick up time on the bridgestones. Advans would probably be the best for you, but unfortunately you would have to go to 17's. Which would probably negate any gain.

[RayAR]

Tire war in the ST classes. Pretty soon the legal tires will be just as fast as R-compounds and probably last as long. Just wondering how many competitive options are available for ST competitors? Falken, Bridgstone, Yokohama, Kuhmo. Any others?

[fastneons]

Falken, Bridgstone, Yokohama, Kuhmo. Any others?

Hankook RS-2, new toyo(maybe)!

[WD40]

So...
Where does that leave a 2,650-2,750lb car???

I would say overmatched in STS, but don't worry anyone who is not driving an 89 civic has the same problem.

I appreciate the feedback, but "Nationals" has never been nor will be anywhere near my radar screen.
And (you probably already know this) I'd rather place last in a Pinto, than win in a Honda.
I bleed Ford Blue just as bad as you bleed Dodge Orange?

My goal, is to be competitive locally, and maybe travel to a couple neighboring states' events from time to time.
I applaud all that do go to Nationals, and am impressed at the effort.
But, it's not in the cards for me.
I also gotta problem with where SCCA Solo has ended up.
"Stock" vehicles running $5,000 shocks, and R-Compound tires?
What showroom stock model is that?
Kinda reminds me of NASCAR Stock cars...nothing near stock.
---off soap box---

So...
Where does that leave a 2,650-2,750lb car???

I would still say, that you would pick up time on the bridgestones.
Advans would probably be the best for you, but unfortunately you would have to go to 17's.
Which would probably negate any gain.

^^^Now, that's the answer I was looking for.
And, you're right about the loss of performance with the 17's.
It's a rather susbstantial difference with the 215/45/16 vs 225/45/17.
Less rotational mass, lower center of gravity, better low end gearing,
quicker transitions through the slalom (or any direction changes for that matter)
are all going to keep me on those 16's for a good bit longer.
Besides...I still got 1/2-3/4 seson of runs left in these tires.
Well...depending upon how often I get down to MMP next summer.

[Dogeater]

"Stock" vehicles running $5,000 shocks, and R-Compound tires?

I agree it's horse S$#t, good thing shocks for my rx-8 will only be $580. The tire thing sucks, cause I'm poor.

I'd rather place last in a Pinto

Isn't that what you have??

I bleed Ford Blue just as bad as you bleed Dodge Orange?

I believe Dodge is RED.

I applaud all that do go to Nationals, and am impressed at the effort.

I accept personal checks.

[RayAR]

I also gotta problem with where SCCA Solo has ended up.
"Stock" vehicles running $5,000 shocks, and R-Compound tires?
What showroom stock model is that?
Kinda reminds me of NASCAR Stock cars...nothing near stock.
---off soap box---

Unfortunatly Solo is just like any other motorsport. Speed costs money, how fast do you want to go? Personally, I am not a big fan of either Stock or SP rules and starting to feel the same way about the ST rules. Like I said in my last post, soon the competitive ST tires will be just as fast as R-compounds and probably won't last any longer. When that happens why even have the ST classes?

[fastneons]

I think people often take the word STOCK too literally. Stock is just a class name. It has nothing to do with the vehicle actualy being stock. It is just a name that the scca assigned to its lowest class structure. If we took the word MODIFIED literally, every car would be in this class. Even worse, STREET MODIFIED vehicles at the national level, never see the street. Sadly, most nationally competitive sp, or st cars don't see the street either. I guess, all that I am saying is, remember these are just words that are assigned to class structures.

[RayAR]

I think people often take the word STOCK too literally. Stock is just a class name. It has nothing to do with the vehicle actualy being stock. It is just a name that the scca assigned to its lowest class structure. If we took the word MODIFIED literally, every car would be in this class. Even worse, STREET MODIFIED vehicles at the national level, never see the street. Sadly, most nationally competitive sp, or st cars don't see the street either. I guess, all that I am saying is, remember these are just words that are assigned to class structures.

You are right Nick, A competitive stock classed car is far from stock. I am sure most nationally competitive cars in any class never see the street.

As far as SM, When I first looked at the rules years ago I knew that it was going to be a stinking fast(and expensive) class some day. Other then following SP chassis and tire rules the cars are virtually unlimited. I like the SM rules because it is the way most people would "modify" a "street" car(Heavily Modified engine in a factory shell), Unfortunantly they left some loop holes in the rules and now it is getting out of hand. This is personal preference but I would rather watch 1 SM car on the course then 20 stock classed cars. Even after 3 years of not running the SM Stealth I know it was a crowd pleaser and I still have people asking me about it on a regular basis. They still remember the car allthough I am not sure if it was because of my insane 6000 RPM launches or if they where just wondering if I was going to curb it again It was a fun car to watch, I can only hope my Camaro will be as popular some day.

[rkaiser]

I'm not sure how this tire will compete but it's listed in the same class as the Yoko and Bridgestone:



http://www.tirerack.com/tires/tires.jsp?tireMake=Dunlop&tireModel=Direzza+Sport+Z1

Tread pattern is quite similar to the Yoko but I have yet to hear anything about the compound or sidewall. It is however, much cheaper than the Yoko AD07.

The Stock class can get pretty crazy for what mods can be done. I personally would like to see some kind of tire size limitations at least. Fitting 275 tire on a car that runs 215 stock seems a bit crazy to me. Maybe limit tire size to 5% of original size for Stock classes.

[RayAR]

The Stock class can get pretty crazy for what mods can be done. I personally would like to see some kind of tire size limitations at least. Fitting 275 tire on a car that runs 215 stock seems a bit crazy to me. Maybe limit tire size to 5% of original size for Stock classes.

Well, I doubt 275's would work well on 7 inch rims but restricting tire size is a good idea. Another idea would be to limit stock class competitors to either OEM shocks or off the shelf non adjustable shocks that are commonly available at any parts store and are not modified. IMHO $1000+ shocks on a stock class car should have never been allowed to happen.

[MikeJ]

Another idea would be to limit stock class competitors to either OEM shocks or off the shelf non adjustable shocks that are commonly available at any parts store and are not modified.

But an ACR like Nick's 2gen and my 1st gen, DO come stock with adjustables ...

[RayAR]

Another idea would be to limit stock class competitors to either OEM shocks or off the shelf non adjustable shocks that are commonly available at any parts store and are not modified.

But an ACR like Nick's 2gen and my 1st gen, DO come stock with adjustables ...

Pretty sure I also put OEM in there. My point being, the single adjustable OEM shocks are not even close to a modified or even stock Koni DA or any of the other Double adjustable performance shocks on the market. I could see limiting the shocks to whatever came on the car and in most cases if a car came with adjustable shocks from the factory they are just single adjustable on rebound valveing.

[rkaiser]

Add one more new tire to the ST crowd:

Toyo



http://www.toyo.com/docs/tires/tires.asp?lpid=30251&name=Proxes%20R1R%99&category=sport

[Dogeater]

Nice tire, all of the 18" sizes will fit my RX-8

[fastneons]

I think this tire may have been mentioned previously, in this thread. I just can't recall by who