New Kumho Ecsta tire report

[sthomas]

As I have decided to try competing in Solo 1 this year, I figured it was time to try some new R compound tires. I am driving a 2001 BMW 330i. Anyways, my buddies at BMWCC mostly suggested the Toyo R1's. While shopping around I found the Toyo's for $300 plus tax + installation and the Kumho's for $240 installed. Given the price difference, and that Kumho is a sponsor I decided to go with the Kumho's. I did mention that I had heard that the older Kumho's (Victoracer's) had a tendancy to wear to outside edges badly on cars with stock suspension (no negative camber) but I was assurred that these new tires were much improved in that respect.

My first (and only to date) experience with them was at Shannonville a few weeks ago. I ran both tracks as part of a BMWCC driving school weekend. This amounted to about seven 25 minute sets - with two of these being slower 'learn the track' runs.

Results: Well, I must say that I was EXTREMELY dissappointed with the tire wear. After my third session on Saturday, I had to rotate the left tires (front to back) since I was worried about cording the front left. I was also concerned by the way that the centre was wearing (check out the picture attached). I tried various tire pressures from 33 to 39 psi, with little apparent change in wear. As for grip - these tires were good. No complaints at all.

Conclusion: I don't have a lot of experience with racing and tires - but I did show these tires to several experienced people at the event - all of whom were surprised by the tire wear. I did go back to the store I purchased the tires at and the owner sent them to somebody at Kumho to look at. Apparently the wear is consistent with my driving according to this Kumho person. Anyways, I will leave this for you all to decide. Me, I'm going to take the original advise, and try the Toyo's when the Kumho's are (soon) dead.

Cheers
Shane

[Dave Barker]

Shane , were your tires left at the Scarborough wheel and Tire zone store ? I was there earlier today and looked at a mounted set of tires . BTW did you heat cycle your tires ? Also what pressures were you running ??

[Taylor]

Christian Sorenson has the Ecsta's on his car and he had them on at Shannonville (I think it was) for an afternoon. He's run 3 days at Mosport on them, I'd guess maybe 500kms over 3 days and they still look pretty good.

However these are extremely soft tires, dead cold they pick up pebbles and stuff. I think these need to be looked at as the closest thing to a street legal hoosier you'll get.

You'll have to ask Chris how they performed though. I'm on Victoracers.

[Dave Barker]

On the SCCA forums , there is some discussion re Kumho changing the compounds from batch to batch with some of the original Ecsta tires having the Victoracer compound . I picked mine up and look forward to using them but wish my rims were another inch wider .

[Chris P]

"Found this interesting info on the SCCA forums: A Kumho USA representative speaking at a recent enthusiast gathering was quoted as admitting that ALL the Ecsta V700s brought into the states thus far were "mistakenly" built using the older Victorracer rubber compound rather than their new "high grip compound".
So that means that all of us who have bought the "new" Ecstas actually received Victorracers with a worse tread pattern!
Each tire has a four digit number stamped on only one sidewall. For instance, my V700's have 4701 on them. 47 is most likely week of manufacture with 01 representing the year. Someone else on the forums had heard that anything made in 2001 has the old compound. It'll be interesting to see what they'll be like later this summer when I'll probably need new ones.

BTW--I forgot to mention that my V700's are mounted on 13"x8.5" Panasports as well. Narrower wheels might make a difference as far as what pressures are good.
"

"
After doing some more looking re: the V700's I found this quote: "Kumho has been continually testing different compounds and constructions of tires in very limited quantities. Some have worked better for road racing, some have not worked at all. autox ? I don't know."
"On a road course the Ecsta is very similar to the Victoracer. It is lighter and faster but wears faster also. The Ecsta tires I have worn out already were definitely not the same compound as the Vracer. Is it better than the Hoosier, I don't know, the season is just getting started."

"I think Kumho wants to provide a durable yet competitive tire (Vracer)for the average road racer/ autoxer yet they still wants to provide a super sticky tire (Ecsta) that wears faster but may give Kumho a few more National Championships at both the Runoffs and Topeka. More choices for us and at an affordable price too."

I think it's likely that they are working to determine what will make the best all-around compound for the new tire and we'll probably see the tire mature very well by mid-summer.
"

[sthomas]

Yes Dave, those were my tires at the Scarborough Wheel & Tire.

Heat Cycling - I asked about this before using the tires and was told it was not necessary - so no, I did not heat cycle them. Pressure - I tried 33, 35, 37 and 39. It was tough to tell if any pressure was better or not. The response I got from Kumho gave no suggestions on pressure - they seemed to feel that I was to hard on the tires. (Of course I was running with an instructor for 3/4's of the time...)

Chris - interesting information. I'll check the 'build number' on my tires. Plus, it's nice to know the difference between the Ecsta and the Victoracer. I was looking for a longer lived tire (can't afford to run the 'Hoosier' quality) and perhaps I was sold/bought the wrong one...

Anybody have information about running these tires backwords? They indicate a rotation direction - is this only for rain? I'd hate to throw out a pair of tires with good tread on the inside.

[Brent]

ECSTA V700- Because of the directional tread design and symmetric internal construction racers can remount the Ecsta V700 "inside-out" to extend the life of the tires.

[Chris P]

Like Brent already said, you can remont the tires. However they will be relatively slippery the first time, maybe weekend you use them.

[Rob McAuley]

I just came from a weekend Mosport, where wife-Sue and I did the BMW School. I did 3 days and she did 2, sharing the car.

We saw the centre tread block wearing funny by end of day Friday, but there seemed to be lots of rubber left. By Sunday morning, we had corded the outside edge of the left front tire.

I swapped the left side, front for rear, and now have 2 corded tires along the outside edge.

I'm going to swap them on the rims and try them at DDT for the F2000 school.

Performance-wise, I was able to carry more speed through the corners than on the Toyos. Breakaway was gradual like the Toyos - likely more gradual than the Hoosiers (any comments, Christian?).

We missed you, Shane! You were on the student list, but you didn't show.

[sthomas]

I dropped out about 6 weeks ago. I was in Canmore (near Banff) visiting my brand new neice.

I will try to make the next one though. Need to keep tabs on the competition :)

[Dave Barker]

Shane , the tires I saw didn't look so bad but were in need of a lot more camber . Heat cycling probably doesn't make the tire any faster but makes it last quite a bit longer at least according to Tire Rack .

Rob , was your problem also inadequate neg camber ?

[Rob McAuley]

I'm set to stock camber settings - about 0.5 degrees negative.

I had similar wear over 3 weekends in my Toyos last year, but swapped them on the rims before the cords started showing.

I'll swap them this week, and see how they hold up at DDT for the F2000 school this weekend.

From what I can tell, better grip than the Toyos, but faster wear. Less ultimate grip than the Hoosiers, but more gradual breakaway. I only ran Hoosiers one day last year, so we'll have to wait to hear from Christian.

[Marsh]

I scrubbed mine in the other day. I noticed two things right away. Very soft side walls for a competition tire (almost as comfortable to ride on as my street tires), and tons of grip. I didn't rip on them, but took some off ramps at a good clip and could even detect any slip angle. So, yea I'm a little concerened about camber. I'm running around -1.5 (non adjustable) and this worked really well on the old kumhos as well as my street rubber.

BTW mine are stamped 0802, so they are supposedly the newer compound.

[FightinIrish]

did you buy your tires at wheel/tire zone? or just mount them there?

what size was the $300 quote for?

[Bad Karma]

Originally posted by Rob McAuley
I'm set to stock camber settings - about 0.5 degrees negative.

I had similar wear over 3 weekends in my Toyos last year, but swapped them on the rims before the cords started showing.

I'll swap them this week, and see how they hold up at DDT for the F2000 school this weekend.

From what I can tell, better grip than the Toyos, but faster wear. Less ultimate grip than the Hoosiers, but more gradual breakaway. I only ran Hoosiers one day last year, so we'll have to wait to hear from Christian.

Go for the ghetto fix. Add some washers in, and dial in some negative camber that way.

Steve G. does it all the time, in spite of John's protests. It works quite well on the E36 3 series.

Most serious club racers do the same thing.


Pat

[sthomas]

I don't think you can do this a remain Stock. Of course, maybe this is one of the many pressures to move to SS2, etc... I guess that I will just have the tires rotated on the wheels and wear-out the other side as well!

[Dave]

Here's the response of Kumho about the new V700 compound.

http://www.kumhousa.com/pages/ev700special.htm

Interesting to hear that Marshall already has the newer compound and that he thinks the sidewall is soft. I thought the sidewall was supposed to be stiffer than before. Hmmm.

BTW sthomas, whoever told you that you don't need to heat cycle r-compounds is out to lunch. You will reduce the tread life of your race tires significantly if you don't heat cycle them. This doesn't generally hold true for street tires, but for R-compounds it definitely does. Visit Tirerack's website for info on heat cycling.

Cheers,
Dave

[Christian Sorensen]

Its too bad that Kumho doesn't have any 'care & feeding' info on its otherwise excellent website.

Everyone is fumbling around in the dark for tire pressures!

I've got a set of 235x40R17s that I have used during the BMW club's school at Mosport's big track April 19-21. They got an initial heat cycle or two a couple of weeks before during the afternoon of the second day of the HRC School at Shannonville.

I started mine off with 37psi front & 34psi cold and saw them climb to 45-49psi front & 43-44psi rear after a session depending on how hard I used them.

On the second day I bumped up the rear cold pressure to 35psi and saw hot pressures ranging from 44-47psi.

I felt that the tires gripped way better than the Yokohamas I've used before on that track but somewhat less than the Hoosiers. Initial turn-in feel was a little more greasy than the instantaneous feedback the Hoosiers give but I can't honestly say there was any less 'constant' grip.

Wear was pretty even across the surface: certainly nothing like the 'scalloping' that has been reported with stock-suspended cars. I rotated them once during the weekend and feel that they are perhaps 20-25% worn now.

Since Nick has them stashed in the back of his truck I can't verify their build date, but I purchased them from Wheel&Tire Zone at the beginning of April.

http://members.rogers.com/cpsorensen/images/CPS changing tires.jpg

[Dave]

Interesting report, Chris. So is the Action Front team ditching Hoosiers this year for Kumhos? Enquiring minds want to know :)

[Christian Sorensen]

The Kumhos are meant to replace my Yokohama 'practice' tires.

Last year I found that the Yokes were so different and their limits so much lower than the Hoosiers that I really didn't benefit too much from track time with them. After a day practicing with the Yokohamas I'd go out on the Hoosiers and have to rethink all my corner entry speeds, during the timed sessions!

Certainly I intend to compare the Kumhos directly to the Hoosiers early in the season, and make my decision then on what to run on.:rolleyes:

[Bad Karma]

Of course, for the BMW school in April, you were hardly on the track, so the wear could be indicative of low driving times.

I've heard grip may be excellent (on par if not in excess of RA1s), but life appears to suffer.

I've got 5 full days on my RA1s, and they're about 50% worn, though I did manage to cord one of them.

I'm holding off on the new Kumho's until I see some solid life cycle type results for them.

On a side note, what prices are people paying for the new Kumho's in 235/40/17s?


Pat

[ctenche]

There's no doubt that the Kumhos, either old or new, have a shorter life span then the RA-1s. They're somewhere in between the RA-1 and the Hoosiers in both life span and grip.

[Dave]

I agree with Caius, the Kumhos have more grip and crisper turn-in but the Toyos last twice as long. If finding that extra few tenths is your goal the Kumhos are a great buy, but if you're just starting out and need with long treadlife and general durability the Toyos or Yokohamas are tough to beat IMO.

Honestly, it's all economies of scale with race tires. The faster you want to go, the more expensive your tires costs are going to be because the stickier tires don't last as long (and tend to be more expensive) and the harder you drive on your tires the shorter their lifespan will obviously be.

[sthomas]

Pat - I paid $240 for the Kumhos - 235/40 17's at Wheel&Tire Zone in Scarborough.

[Bad Karma]

Originally posted by Dave
I agree with Caius, the Kumhos have more grip and crisper turn-in but the Toyos last twice as long. If finding that extra few tenths is your goal the Kumhos are a great buy, but if you're just starting out and need with long treadlife and general durability the Toyos or Yokohamas are tough to beat IMO.

Honestly, it's all economies of scale with race tires. The faster you want to go, the more expensive your tires costs are going to be because the stickier tires don't last as long (and tend to be more expensive) and the harder you drive on your tires the shorter their lifespan will obviously be.

Hmm, that's interesting. I had heard, from several driving instructors in the U.S., that they had been more favourable towards the Kumho's, due to cheaper price, greater availability (in the U.S.), and life equal to that of the Toyo's.

All other things being equal, the nearly $100 per tire is an appealing part of the Kumho's, since I tend to burn off my RA1s pretty quickly anyway (damn heavy BMWs....).

I figure I can probably get 8-9 solid days out of a set of RA1s; if I could get similar results (with equivalent if not better grip) from the Kumho's, I'd go that route. If I only got half that much life from them, then the additional grip isn't worth it, and I'd go RS303s instead (for Solo 1 events, and RA1s for schools).

Shane, how is the life of your tires looking?


Pat

[sthomas]

It is hard for me to estimate the life in my tires. Currently, I only have the two BMWCC days at Shannonville on them. Keep in mind that one of these days is really only ~2 hours of track time... I would say that the two left tires are ~65% worn and the rights are ~40% worn. I'd guess that I would get another 4-6 school days with appropriate rotation. How this measures up to track days, or Solo 1 events - I couldn't say.

[Bad Karma]

Ok, for comparison sake, let's look at how much I have on my RA1s.

I have two heat cycles on them (basically, a drive up the 401 to Pickering, and a drive back a few hours later). Not *great* heat cycling, but somewhat better than a kick in the head.

The two days at the BMWCC school in Shannonville, of which my car saw double duty on the Sunday, with John driving it as well. Effectively, I could *almost* call that three days. I believe there is certainly more track time involved in a BMW CC school than a Solo 1 day. (I'll guess roughly 3-4 times more track time...depending on how much open lapping one gets at the end of the day).

Three full days at Mosport for late April, of which the Friday gets roughly 4-5 hours of solid track time, and 5 sessions each other day (4 student session of 1/2 hour each, and 1 instructor session of a 1/2 hour). So, all in all, roughly 10 more hard, track hours. Likely the equivalent of 4 *normal* days between those three.

So, I'm figuring I'm at roughly 50% wear, with effectively 7 days of *normal* driving schools on them. Even with half the track time at a Solo 1 event compared to a BMWCC event, 14 events a person could *almost* get a full season on one set of RA1s (in reality not likely, but in practice probably not too far off).

So, for the guys who Solo 1 regularly, is my math too far off?

It might actually be more cost effective for me to do some Solo 1 weekends after all, as I had originally thought it to be the standard 2-3 hours of driving school time...

Hmm, might have to jump on the bandwagon after all....

Pat

[Dave Barker]

My Kumho Victoracers lasted for 10 Solo 1 events , a lapping evening at SMP and still have lots of wear left , this on a very heavy Camaro . Un fortunately they have been heat cycled so often that they are now hard enough to be relegated to the ranks of lapping day tire only . ( I am using the story of becoming hard by the end of the season as my excuse as to why I got propositioned by John P. on Fabi at the last event last season )( Beat by a Honda , will take me a long time to live that one down)

BTW folks comparing tire wear at the real track at Mosport (not the Honda track ) with wear at SMP is like comparing Cherry and Beefsteak tomatoes ( not really apples and oranges ) I would guess that one hour at SMP wears my tires more than 3 hours does at Mosport . ( Probably comes from just being a chicken s*** at Mosport )

[Chris P]

Beat by a honda eh, live it down, never! Now that you've met Mr. Honda, say hello to Mr. Toyota. :)

[Bad Karma]

Originally posted by Dave Barker
BTW folks comparing tire wear at the real track at Mosport (not the Honda track ) with wear at SMP is like comparing Cherry and Beefsteak tomatoes ( not really apples and oranges ) I would guess that one hour at SMP wears my tires more than 3 hours does at Mosport . ( Probably comes from just being a chicken s*** at Mosport )

Well, I'd suggest that's a large part of it, though I have no idea of how you drive, so I'm just going with your suggestion.

I actually saw more wear from Mosport than I did from SMP, but I take corner 2 and corner 4 at Mosport pretty much flat out, so that may indicate something...

Mosport is MUCH easier on my brake pads however....


Pat

[Marsh]

Well a small update. I finally got some dry time on them at the Delaware "King of the Hill" race. The soft side walls will take some getting used to. My word at the time was "Squidgy". It took a LOT of courage to floor it in turn 3 at 100km/h, where last year I would have had no problem. I'm still having major problems with under damping, so I'll hold judgement till after the new suspension arrives.

Don't get me wrong. The grip was there. It just took giant elephant balls to find it.

[Jay]

I don't have heaps of experience with R compounds. I have used BFG R1's, Kumho V700's and now the new Ecsta's.....

Events 1 and 2 were not very good days to evaluate anything (Except maybe a block heater :) ) it was soo cold.

I will say that my initial experience with the new Ecsta's is that they provide TONS of grip... seemingly more than the V700's although at this point I have heard that the actual compound used in the Ecstas is the same as the V700 compound.

They also did not wear much. Although I suspect that observation has to do mainly with the very cold temps.

Maybe I am biased because I scored my first class win last weekend, but I will say that my initial experience with Ecsta's is that they provide LOTS AND LOTS of grip.