Kumho Ecsta V700

[Kai SRT10]

Time to write about my new Kumho Ecsta V700 tires.

I bought them as replacements for my Michelin Pilot Sport Cups. I liked the Sport Cups well enough, but I figured why not try something new.

I bought them from Vilven Tire (217) 583-3277
Tire Rack was out of stock on them.
Price (unshaved) is $228 for the 305/30/18 and $241 for the 335/30/18.

I paid (I think) about 15 bucks a tire to get them shaved to 4/32.

The tires fit fine on my SSR wheels, which are 18x11 up front and 18x13 in the rear. The front tires are a bit fatter and the rears are a bit thinner than the 295 front and 345 rears I was running with the Sport Cups.

I ran a couple of track sessions with them before my engine blew up, but it was enough to form some impressions.

The Kumhos take much less time to come up to grippy operating temperature than the Sport Cups. When warmed up, I would say that they have a tad more grip than the Sport Cups (perhaps aided by the fatter front tires.) I haven't used them enough to know for sure how well the Kumhos will wear, but based on the rubber wear from my partial track day, my guess is that they will wear out quicker than the Sport Cups.

So. It seems that the Kumhos are a bit stickier and cost a little less, while the Sport Cups will last longer. One thing about the Sport Cups longevity, however, is that even though the rubber doesn't wear out, the tires get a bit "greasy" long before the rubber wears off. I found that in the latter part of the Sport Cup's useful life, the amount of time where the tire was in it's grippy sweet spot got shorter and shorter. When I retired my Sport Cups, they still had sufficient tread to be used at several more track days, but they had lost their grippy characteristics.

I haven't used the Kumhos enough to know how long the rubber will last, or how long their grip will last. Until I have more experience with the Kumho's longevity, I can't as yet determine which tires I will choose when it comes time to buy new ones again.

[Early93Viper]

I have about 6500 miles on mine. They still have tread but don't seem to be as sticky (too many heat cycles). What I really like about Kumhos is that they seem to be more forgiving at the limit. While I think Pilots have almost as much grip but once you surpass the limit of the tires they just give without very much warning. Very knife edge handling.

I think Kumhos are worth at least a second maybe two on a normal track. Not a bad mod.

[Racer Robbie]

did you ever try running the sport cups on the street? one would think it would be much better than the ps2

[Kai SRT10]

did you ever try running the sport cups on the street? one would think it would be much better than the ps2

I drove the sport cups on the street occasionally. They need a little more time to get warmed up than the stock pilot sports. When cold, they had less traction than the stock tires.

[Racer Robbie]

thanks for the post. At say 65-75 degrees how long and how many miles do they take to come up to temp? How do they perform in all around street driving compared to Ps2 tires? Do they wear faster than the stock tire?

[Kai SRT10]

I've never driven PS2 tires, so I couldn't really compare them. The cups wear much much faster than the stock tires (which are actually very durable for high performance tires.)

Give the sport cups 5-10 minutes of "spirited" driving to warm them up. Just regular city driving won't do it. When using them for "canyon carving," I am cautious for the first 5 or 10 minutes, slowly warming them up.

[Vipera Russelli]

Why would the cups get "greasy" long before the tread was worn??? I don't understand that. Does the rubber get hard after having been heated and cooled a number of times?

Also, did you have your sport cups heat cycled when you purchased them?

[Kai SRT10]

Why would the cups get "greasy" long before the tread was worn??? I don't understand that. Does the rubber get hard after having been heated and cooled a number of times?

Also, did you have your sport cups heat cycled when you purchased them?

Repeated heat cycling will cause all tires to lose grip. The Sport Cups held their grip a long long time. However, because they are so durable, I think that after a while the heat cyling caught up with them.

I don't think that this is a negative, and I don't think that the Sport Cups react to heat cycling any worse than other high performance tires. In fact, based on the experiences of me and my driving instructor with Sport Cups, my conclusion is that Sport Cups seem to be less affected by heat cycling than other tires. It's just that the rubber compounds are so durable, that the rubber will outlast the grip, so to speak. With less durable tires, you wear out the rubber about the same time that you wear out the grip due to heat cycling. The kind of driving I do (lots of track days with multiple heat cycles on each track day) is bound to exacerbate loss of grip due to heat cycling.

So, I still think that Sport Cups are good tires, and their relative durability may lead me back to Sport Cups when my Kumhos wear out. How quickly the Kumhos wear and how resistant they are to loss of grip due to heat cycling will likely be the deciding factor.

And no, I didn't get my Sport Cups or Kumhos heat cycled from the dealer.

[VENOMAHOLIC]

Just mounted my Kumhos on the rear rims last week and I notice much better traction under acceleration than Pilots. I used to get a little wheel spin even in 4th. I am steadily testing the limits on the street but so far it is much better in as low as 2nd gear.

I am much more confident when pulling out into traffic that I will not spin out. I also feel more confident, under acceleraton, that it will be straighter and not go sideways.

I believe that tread life is not as important as having much better control. I do not want to wreck my Viper and have lots of tread left on Pilots. The cheaper price of the Kumhos ($100) and the much improved traction, in my experience on a stock RT/10, so far have convinced me that Kumhos are the way to go.