Kumgo Ecsta MX blistered on me

[algs911]

Hey folks,

We had a great autocross this past weekend. I had to stop short though. Check out the picture. I blistered my left rear Kumho Ecsta MX. I'd never done that before!

Good tires, overall. Soft sidewall made for slower times, yet predictable handling. Suprisingly, they lasted eight months (I had some Yoko ES100s which lasted three!).

Now, where to go from here? New tires, obviously. This is my weekend car (I have another, daily driver) which is used on dry days only. I AX 8 to 10 times a year and will be doing at least two track days next year.

Any suggestions?

Thanks,

Alan

[HarryD]

Originally posted by algs911
Hey folks,

We had a great autocross this past weekend. I had to stop short though. Check out the picture. I blistered my left rear Kumho Ecsta MX. I'd never done that before!

Good tires, overall. Soft sidewall made for slower times, yet predictable handling. Suprisingly, they lasted eight months (I had some Yoko ES100s which lasted three!).

Now, where to go from here? New tires, obviously. This is my weekend car (I have another, daily driver) which is used on dry days only. I AX 8 to 10 times a year and will be doing at least two track days next year.

Any suggestions?

Thanks,

Alan

Hi Allen:

Sorry about your bad luck but looking at the picture, it sure looks like your tires are seriously underinflated for AX unless I am seeing a rubbing fender. From what I see you are rolling heavily into the sidewall. When you chalked the sidewalls, how close to the edge triangles do you get?

I am running ES100's on my car for the past year and have done about 10 AX's and about 4-5,000 total miles. At AX, when I check my chalk marks, they are worn only to the tip of the triangle. I need to run about 34 psi front and 39 psi rear to do this. They still look pretty good. How did you kill yours so fast?

[algs911]

Hello Harry,

Thanks for the post. I've been running 34/39 psi as well. That's the things with these tires, they're so flexible in the sidewall area it's not even funny! I once ran 45 just to try it out, they still rolled over a lot, AND I went slower. To answer your question, they roll over a lot! I played with pressure and deflated the rears a bit for one run, I think that's the wear down the side you're seeing.

So, maybe I need to try out the ES100s again. I did get three months out of the last pair, but that was a couple of years ago (if I remember correctly) when I was JUST beginning to AX. I was a lot more wild back then!

I've been killing tires though. It may have something to do with the surface we AX on. I rent out a portion of the Marina Municipal Airport (near Monterey, Ca.) and we run on cement (there are air plane tie downs all over the place). I think it's like sand paper!

Al

[Joe Bob]

Kumhos have their limits..they are cheap so they are popular. What series tire are you running?

I use a 45 front and rear.....

[algs911]

Hello mikez,

I'm running 205/55zr16 front and 225/55zr16 rear. Do you recommend a 45 series tire? I'm looking at tires now and plan on making a decision in the next week or so.

Thanks,

Alan

[Bryan Beaumont]

Try an R compound tire. Should work fine for your weekend car.
For the money hard to beat Toyo RA-1's.

[Joe Bob]

Less side wall...less roll. A bit harsher ride.....but who cares, yer supposed to feel the road.

[Bryan Beaumont]

Does you car have SC flares? If so, run 245/45-16 and 225/50-16.
Will fit with NO problems, and you will not believe how your car sticks
compared to the Mx's.

[algs911]

Great responses. Thanks folks.

I'll check out the Toyo RA-1s. Where do you get them?

I don't mind feeling the road at all. I assume going with a 45 series tire will lower the front a little, eh?

I have an '86 Carrera coupe, so yes, I have SC flares.

[Bryan Beaumont]

bobwoodmantires.com----print out the page with the sizes you need and take it to the biggest local Toyo dealer, I bet they will either match or
be real close.
225/50-16 & 245/45-16 is close to an ideal match, tire diameter is
24.8 for the 225 & 24.6 for the 245.
Are you running 16x7 & 8's? If you are running 6 & 7's you should
probably go no bigger than 225.
Good Luck

[skinnerd]

I 2nd the Toyo RA1's.
They are my tire of choice now.
Relatively cheap, no heat cycling required, long lasting, great grip, no bad habits.
What's not to like about them?
Not sure about sizes, but I think there are a bunch?
I've got the 225's and 245's on my 16x7 and 16x8 Fuchs.

I've had them on the track now a couple of times, and they are incredible.
Never go away or feel greasy no matter how hard I drive them.

[Noel]

I've had the ES100s and the MXs and much prefer the MX for track work. Firmer sidewall than the ES100s.

To me that photos looks less like a blister and more like sliding and a portion of the tire ripped off. I used to use the old BFG G-force R1 tires and when they got thin this would happen at a very abbrasive autocross location I used to run. Generally your tires would never get that hot during a typical autocross run to cause overheating problems.

[Craig 930 RS]

http://www.caranddriver.com/article...rticle_id=10252

[Kevin Stewart]

Have you ever tried heat cyling before youbhit the track, works great, it does look like your car may be to tight, do you have to blip the throttle to get around the corner,

[Craig 930 RS]

MXs get brutalized at our local track - I don't recommend them for track use. Beter choices are out there

[cbeers]

+1 with Noel.

I went through two sets of the ES100s and the MXs are MUCH better in my opinion. Last just as long, but much stickier.

I'll have to look at Craig's link now though

-Chris

[Noel]

MXs are ~$85 ea and much wear much better than a R compund. I'll take that everyday. Plus...you actually have to learn how to drive your car while using them. Ive done a lot of Autocrosses and DEs and I still love street tires.

BTW, Craig, I was surprised to see that the MXs finished last in the C&D survey and the Goodyears finished first. My buddy, who is an equal driver to me, likes the MX better and has used both the Goodyears and the MXs. Interesting.

[Craig 930 RS]

What would I try for a non R compound full tread ?
--------------------

Fifth Place
Hankook Ventus R-S2 Z212

The Hankook has one feature the other tires can't match—a $99 price. And to its credit, the Hankook didn't behave like the cheapest tire, particularly when the track was dry. It tied the $175 Yokohama and $145 Goodyear for second place in lateral grip, scoring 0.94 g. And although its dry-braking results landed it in last place, that shortcoming did not greatly affect the Hankook's dry-autocross showing—a 29.86-second average, a third-place result that was only 0.20 second away from the winning effort.

It became apparent that the Hankook was clearly tuned for dry running as its wet-track results were below average. Like the other poor runners in water, the Hankook felt greasy and was slow to recover once it broke traction. But in the dry, the Korean tire felt just as responsive and sticky as its more-expensive competition.

The thing is, though, the harder you drive, the more tread you'll burn off a tire. So if you're a track-day addict who doesn't mind sacrificing some wet-weather capabilities, the Hankook is a choice that will save you money without losing much performance.

Hankook Ventus R-S2 Z212 Typical selling price $99

Service designation* 94Y

UTQG tread-wear grade 200

Weight, lb 23.6

[juanbenae]

i have MX's and those appear to be rolling over a LOT. mine have rolled over but not near that. the wear indicators are long gone on those.

[HarryD]

Hi,

I was thinking some more on your comments about short tire life and it has me wondering if you have an alignment or weight balance issue as well. You may want to visit a shop that specializes in setting up 911's for the track and see what they think. I am fortunate to have Rothsport Road and Race nearby. Jeff and his team really know their stuff. He was the one who did the final tuning (lower/align/corner balance) of my suspension and it rocks.

For your reference, here is a shot of my 205/55-15 Yoko ES 100's with 8 Autocrosses and 4000 miles:



As you can see, I have limited my wear to the thread area and you can still (barely due to the flash) see the wear triangles. I would expect to get 10-15,000 miles out of these tires.

Anyway, whatever you decide, best of luck.