erko1905

This is my second set of Dunlops now, first set was good till cords, but I’ve never seen wear like this:

Front left

This set has two days at the Glen and two days at NJMP Lightning, this is after second session at Thunderbolt, day 1.

It seems like the sticky good stuff is peeling off, but its not throughout the tire, only about a quarter of it has it. I made a few mistakes this last session I wonder if the car slided two much sideways, but even then peeling off like this shouldnt happen right ?

Happy to hear thoughts/comments from anyone who has seen similar or has a guess at if this is manageable.

iphilips

Don't want to make this yet another alignment thread but what is your alignment? Is the wear only on the outer edge? Both sides?

erko1905

-2 all around. It’s been wearing fine w that camber for the whole season though, this surface peel is new.

erko1905

Seems to be getting worse?

It does grip at a manageable level, wonder if its ill advised to at least complete the day - in this condition it’s still within 6-7 tenths of previous PB

EST

Are these Maxx Race 2 or ... ?

erko1905

Yep, Sport Maxx Race 2

EST

Strange - TRAKCAR wrote that he likes these more than Cup 2 tires.

Waxer

I would not use them again. Did they just chunk suddenly like that? Looks like it was gradual wear.

Did your first set do the same?

Send pick to Dunlop and ask.

To me it looks like you continued to use the tire long after the wear came over the shoulder of the edge of the tire.

awew911

I would not go on track with those...

I'm on my third set of Dunlops on my 991.2 RS. I'm not the fastest one out there but have run them at Sebring (2:18), Road Atlanta and VIR (2:04). Never had that problem. I start fronts at 24 psi and SLOWLY build up to 28 (adjust during session). Rears 28 and build to 32.

Camber 2.5 degrees front, 2.2 rear. zero toe up front. spec toe in rear.

They last longer for me than Sport Cup 2's.

erko1905

It happened over two sessions max, at least that’s when I noticed it, I did inspect them before coming here. This was a very cold morning though, low 40s first morning session, cold enough that first session I just went out w regular street pressures.

First set didn't do the same, even-ish wear for like some 10+ track days.

Good idea to submit to Dunlop- will do that.

So I drove 3 more sessions after that first photo, trying to manage the situation via cleaner driving, running 1:31s mostly which is a bit slow but not horrible- had to work a bit harder to keep the car on track w the decreasing front left grip, so now it looks like:


So at least I finished the day, I think common sense would dictate to go home tomorrow morning.

I think this might be it for my Dunlop Sport Maxx 2 experiment. Will try to run something that doesn’t peel off next season.

orthojoe

Bizarre. I'm on my 4th set of dunlops now and I have yet to see any issues with delamination. What pressures are people going out and running at? I seem to run higher pressures than most. Maybe that is the issue? I start out at 27/29psi stone cold, bring it down to 33/35 hot after the first session. After that, pressures go up as high as 35/38 but I DON'T bleed out pressures. I run consistent times all day this way and no delamination issues yet. I just ran a new PB at Laguna today using this method

erko1905

I was running 35 hot all around - never went out with anything below 28-29. Waited a lap or two before I push.

I talked to a racer who was test/tuning his trans am spec Mustang, this dude is running 6-7 seconds faster than me at this track easy - they apparently have delamination issues when the tire is an older date code- so I checked, despite having bought these mid 2019, theyre actually 26 17 code, so maybe that’s a factor. I was sure Trofeo Rs were the next stop but apparently he had the Trofeo Rs delaminate the same way- so not a clear negative for the Dunlop yet, just the perfect storm for this tire this time I guess, too cold, old production date, I might’ve pushed too hard admittedly, also abrasive track on left fronts in general.

TRAKCAR

I only used one set, faster and held up a bit better but final verdict will be known after I start with new Dunlops and kill them at Sebring where I have a better base line.

Work is so getting in the way of the important stuff.
Someone with more time for nonsense should by me out, so I can focus on track days.

Akunob

Had the same delamination on my first set of Dunlops, my second set chunked, I’m on the fence about buying a third set. To be fair this occurred on the 8th track day, hence why I bought another set. In my case a more aggressive alignment was necessary. I suggest you pay John, at Apex, a visit.

erko1905

I was feeling brave today so I did two more sessions on those tires, at that point the rear left started cording on the outside and front left started some small chunking in the mid section of the tire as well, so I called it a day at that point. So you can run these a bit further after they start falling apart it seems, with careful monitoring. The very last lap still only 6 tenths off PB, so they don’t slow down, which is really great.

Thanks all for chiming in.