So Kumho says their Ecsta V700 DOTR must be shaved
when used in the dry otherwise excessive wear will
occur. Is this true? Do I really *need* to shave a
new tire? This is for a track only car used in track school HPDE 3
& 4 this summer being driven HARD. I was hoping to use them full tread
and get a little more life out of them...

From Tirerack.com's website:

Notice:

The ECSTA V700 must be shaved to 3/32" - 4/32" tread
depth for any autocross or track use in the dry.

Kumho advises that the ECSTA V700 DOT-legal
competition radial must be shaved prior to use in dry
conditions. If this tire is not shaved, excessive wear
may occur causing the tire to wear to the cords
prematurely in a localized area.

The ECSTA V700 should only be used at full tread depth
(6/32") for wet track and wet autocross use


Thanks,
brad

 

If you are using them on a road course and are able to hustle the car hard you probably want them shaved. This keeps the tire from overheating and the tread from chunking. Autox you can get away without shaving them as the tires don't stay hot long.

 

Yeah, what he said. They'll last longer and perform better shaved. I got 4 good weekends out of my last set. That's qualifying and racing both days.

 

They did change compounds on the Ecsta, the new compound is substantially softer according to Grassroots. I'd call Kumho for clarification. Kumho has always recomended shaving for dry road race. AX, and wet were full tread. If this is true, then the new compound (ko8 vs ko6)may be much softer(perhaps why the hoosiers are manufactured at 4/32nds) I'll bet though that this is all the same old hype, in which case I'll take my full tread V700s vs anything but an RA1, and the shaved competitor will see cords around the same time I can no longer see the tread pattern. I've run full tread kumhos on a 3800lb car on the track for 40 minutes repeatedly in the dry, and never had a problem. Yes a pro driver can chunk out full tread tires in short order, but you are no where near those speeds in NASA HPDE 4. Carl Byck

 

expalin more about this compound change?!?

 

not run the new Kumho's but the same "warning" was given for the v700. I shaved the first couple sets and ran the last 10 or so sets without shaving or heat cycling. they all seemed to last about the same and perform about the same. I was in a hurry and didn't want to wait for the shaving and ran them full tread lasted about 3 full weekends no chunking was seen. In my opinion it is not necessary, but doesn't seem to hurt.

 

The earlier Ecsta V700's have a history of uneven wear and chunking ... usually referred to as the 'groove of doom' as it's spotted. That problem is supposed to be alleviated with this latest revision of the Ecsta V700. So, if you buy them now, supposedly, there shouldn't be any problems with the tires. But, if you've had a set of Ecsta V700's that were made last year, I'd be a little cautious about their usage.

 

Thanks Tim,

Other NASA guys said I shouldn't need to shave them either. "not worth the $ shaving them for hpde 3 or 4" but rest assured, my little 12a Jbridge is one small step away from a racecar and I'll push it real hard.

I ran full tread Yokohoma A32R's in HPDE3 and they didn't chunk either.

No shaving I'll try!

Thanks for the input all

 

Some of the guys from the BMW club have complained about this type of wear with these tires and have gone back to the Victoraces. Some of these tires work better on different cars. This is why some of the heavier Domestics/BMW's have problems with certain tires, Your pretty much in the clear with the lighter RX-7 and can get away with the softer compounds without totally destroying them. for a heavier car I would suggest using the Yoko A032R. Its one of the harder R compounds but may help keep the integrity of the tire for 3200lbs+ cars.

 

Careful, there are two different compounds now available for the AO32. I run V700s full tread on my 3800lb 97TT supra for road race, No problems in three years of racing. The AO32s are not close IMHO, the TOYO RA1 is another goood choice before the AO32. Carl Byck

 

Hmm, I have a set of the earliest of these, I got them when they first came out. I've done 4 driving schools on them so far, and they're still useable and have no chunking. There is a lot of melted crap stuck all over them though, haha.

 

heat cycled my new ecsta 700 tires 2 weekends ago. they stuck real good during the on track session.

 

The compound change by Kuhmo was from the 'formula' they call K8A to K6A. Apparently, the compound designation used is molded into the sidewall - at least on the Ecstas. I have brand new Victoracers, build date week 1 of 2003, and there's no compound indication.
Sooo...., maybe the Ecstas are the softer K6A, hence the 'shave or die' directive, while the Victos are still the K8A.........

 

victoracers came with the same warning.