Kuhmo V710

[Grumpa]

Weighing tire choice for my ITC Rabbit and wondered if anyone has any input on V710's vs. R6's. Depending on whose opinion you read/solicit/overhear, the 710 ranges from sh*t to great, which leaves me scratching my noggin. Also, any opinions/experience with the Avon/Yokohama Advan DOT's?

[Racerlinn]

Jim, I did not have success in that I ran a tire size to small for my 2500# car when I tried them last year. I'm guessing Speedwell may be easier on tires at it's lighter weight. Your mileage may vary....

[CDS]

My experience is that the Hoosiers offer slightly more ultimate grip, while wearing a little faster (but not by much) and are more expensive. I run the V710's mainly for cost reasons, but if I run the ARRC this year (it would be my first time) I may switch to Hoosiers. ITC fields are generally small in the MidDiv races I enter, but with the 710's I've been competitive with Hoosier-shod cars.

[wcmcarlos]

I am running 710's now, and will buy another set when I resume racing in the fall.
205-55-14's, I will probably go to 15's when I replace these.
Good Luck
Carlos

[iambhooper]

I think the 710's are great. They offer awesome grip with good tire life. And on FWD, you can rotate them! I usually buy the 1st 2 tires in a season and then I can get enough contengency to get at least a 2nd pair after a few weekends.

Grip, tread life, contengency... all plus's. Not to mention they are well suited to FWD cars.

[tnord]

if it's a hot weekend, i have a problem keeping tires under me for much more than 5 laps. now, granted i haven't done a lot of set up work with them matching alignment settings to pyrometer readings, but my pressures always come in within a pound. i am fairly restricted on my SM suspension, but i could still do a better job.

they're not bad tires, but i wouldn't say they're as good as hoosiers, or maybe even hankooks. i would say they're a better autox than race tire, but are still adequate.

[tom91ita]

.....I usually buy the 1st 2 tires in a season and then I can get enough contengency to get at least a 2nd pair after a few weekends.

Grip, tread life, contengency... all plus's. Not to mention they are well suited to FWD cars.

i concur. i use them on my 2150 # ITB crx si so your ITC car should be fine.

the Hoosiers may be a little faster but the Kumho contingency is so good. i bought some a few years ago and if you can run up front, you can get "free" tires. i hope to win a couple more fresh tires and save them for the ARRC.

all that said, i have not registered for this year's contingency. better do that now.....

[Grumpa]

I probably should have thrown this out initially. I am running 13 x 6 rims in an effort to keep the cg as low as possible, so the tire size will be 215-225/45-50/13, depending on what the tire companies offer. I don't think Hankook offers a 13" and I'm pretty limited by Hoosier, Kuhmo, Yokohama, etc. I tried 14's, but had clearence issues that were remedied by a ride height increase which had a negative impact on the car's handling. The car is lined at 2000#, but it will require a 180# pilot to make weight and I'm not quite that svelte - fairly far from it in all honesty. The car is pretty good on tires with the setup that I have on it now, although I am going to test a lower-450/500-front rate spring with a higher-550/600 rear rate spring in an effort to get the car to rotate better.

[keycom]

. . . the tire size will be 215-225/45-50/13, depending on what the tire companies offer. I don't think Hankook offers a 13" . . .

Hankook Z214's C51 225/45ZR13

recommended rim 7.0-8.5

Price $147


Frisby lists them at http://www.frisbyracetire.com/hankook_z214.asp

[Grumpa]

Dave,
Thanks for the heads up on the Hankook - how well do they work on a 6" rim? I have heard that on a light car the Hankooks work and wear well.

[shwah]

I run that size Hoosier on a 6" rim. Not ideal, but gets the OD I am after.

[keycom]

I've been running the closeout special Z211's. 205/55-14 Two schools, three races, two days of track sessions with the Porsche guys and a couple of other track days also.

I run at about 2,155 pounds, i.e. 75#'s overweight. Which happens to coincide nicely with MY personal little gravitational problem area. Hope to be at 2,140 next weekend at MAM.

My next-to-last event in 2007 was my last race in Mid September and cool, foggy weather. The last lap of 15 was my fastest lap ever at that track! Three seconds faster than before in early August. And Albin did not lap me!

But I'm new at this, so not all the improvement was from the tires themselves (I hope). Don't mean to be bragging at all, just that I am still on the learning curve and part of the improvement was learning to brake later, come out of corners earlier, and to trust my tires. I'm still 5.x seconds slower than Albin on that track and it was his first time there.

There is still some rubber left in them yet. But I can't honestly say how much "life". I've kept them and remounted them "inside" out. We'll see if I can make use of them on the back end yet without getting too spin happy. (Those who have watched me in the last year know what I'm talkin' 'bout.) I've found six more closed-out Z211's for this season.

Anyway I've heard the Z214's are even better. Though Frisby may have just a few 14's left. Not sure about 13's at all.

As far as rim width goes, I've found the Z211 in 205/55-14 to be near the limit on 6" rims. I mount and balance all my own tires. I'm learning to mount them with a little more ease now.

-------------------------------

Aha, I see Chris says he has used 13's on a 6" rim, so I would trust his judgment over mine for sure. I'm still young at this, but enjoying the learning curve.:026: Good luck!

[roadracer]

anybody know the treadwear numbers for the Z214? In both the C70 sticky compound and the C50.

Also, anybody know how many cycles you might get out of the C70 compound running sprints or an enduro setting. Was wondering how many hours they might last in an enduro.

Or, perhaps comparison to Hoosiers. I have run Hoosiers, V710's but never the Z214. So comparisons to Hoosiers and V710's would give me an idea how they might work.


Thanks for any input.

Don

[philstireservice]

I probably should have thrown this out initially. I am running 13 x 6 rims in an effort to keep the cg as low as possible, so the tire size will be 215-225/45-50/13, depending on what the tire companies offer. I don't think Hankook offers a 13" and I'm pretty limited by Hoosier, Kuhmo, Yokohama, etc. I tried 14's, but had clearence issues that were remedied by a ride height increase which had a negative impact on the car's handling. The car is lined at 2000#, but it will require a 180# pilot to make weight and I'm not quite that svelte - fairly far from it in all honesty. The car is pretty good on tires with the setup that I have on it now, although I am going to test a lower-450/500-front rate spring with a higher-550/600 rear rate spring in an effort to get the car to rotate better.

Hankook does offer a 225/45R13 Z214 C51....

I wouldn't run C70 or C71 in an enduro. The C51 is the ticket for an enduro on Hankooks.

[JimW337]

I am also thinking about switching to the V710 and was wondering what kind of differences in camber and pressures compared to the R6. This would be on an ITB Rabbit at 2080 lbs.

Anyone what to offer up any sugesstions?

JimW

[iambhooper]

Jim, dont switch... keep everything the same... there is no need to put the 710's on your car

That is, unless you want to stick with me through the corners?

[spdmonkey]

I've run the 710's on my SM and love them. As my car is camber challenged they work well. They do not like a lot of camber in my opinion. I ran them the same weekend Steve Linn melted his with no problems. In addition, I do start a bit lower on air pressure then compared to other brands. It all adds up.

db

[Darryl Pritchett]

I am not trying to hijack this thread but while many are asking about the 710's I have a question of concern.

I just switched to Kumo 710's and only scrubbed them in at the last race to save for Daytona. While removing them I noticed, and the best way to describe it is it is like looking at a recap tire. It actually looks like the tread is a recap and is seperating. I cannot say it is actully seperating but it almost has that appearance. My concern obviously is I will be running them at Daytona where you really don't want a tire coming apart. I run 2.5 degrees negative camber in front and 1.5 in the back and all four tire looked the same. If this is normal tread appearance then thats fine it just looks a lot different the anything I have ever seen.

As for the way the handled, they felt real good, could not tell any real difference between the R6's and them.

[tnord]

any way we can see some pictures Darryl?

I've never had any similar experience with mine, but that doesn't mean it isn't possible. I see you run a FWD car, if you are concerned, i'd run that tire in the back.

[keycom]

" I run 2.5 degrees negative camber in front and 1.5 in the back"

From the Tire Rack's "Care and Feeding of the Kumho ECSTA V710":
http://www.tirerack.com/tires/tirete...jsp?techid=155

Your vehicle's alignment settings can influence the performance and durability of your tires and often can be adjusted to maximize their capabilities. Like most tires, the ECSTA V710 features a symmetric internal construction and will require little negative camber to achieve its full potential. If camber is adjustable, most cars will perform best when camber is adjusted into the –0.5° to –1.5° range. Vehicles with a stock suspension should use the higher end of the recommended range for camber setting to ensure proper grip and durability and compensate for the added body role experienced during on-track driving.
The tread profile of the ECSTA V710 is very round compared to our previous generation tires. The shoulder area of the tread must be allowed to work to perform properly. This means allowing the tire to roll over onto the shoulder area by reducing the amount of negative camber. Caster settings can enhance straight line stability and cornering traction, and if adjustable, should be set at the maximum positive value for the vehicle. Toe settings may be adjusted to enhance steering response and corner turn-in.