Coochas

Been there,....

cre8fun

I can ABSOLUTELY assure you that fender interference is not a factor. and I get grooves and cracks on all 8 tire edges and am certainly not having interference on all 8 tire edges.

I agree with you that the tires should be worn up to the edge of the sidewall writing. if you notice it is worn that far in the pictures of the tires that are "done." the picture you marked up shows an edge that was an interior edge and had just been flipped on rim, but has not been run yet. so that's a crack that opened on the first heat cycle and will become grooves once it's run on the outside edge.

as for pressures. for the first heat cycle of the day, I leave the pits at 30 cold. for all remaining, I run 30 hot. as for overpressure, hoosier recommends more like 36-38 depending upon track. most of the corvette community run 28 hot, but since my blow out last year, I've been running a little more pressure (30 hot) because it's closer to what hoosier wants me to run, so I figure it gives me 2 psi of insurance against what I had when I ran 28 hot.

cre8fun

good lord, if that happened on an inner sidewall, you'd never see it

that's crazy. I've never seen that at the track and there are 2 picts in this thread.

jdistefa

Wrong.
Wrong.
...and probably wrong.

Mark have you actually run any 2018 spring/summer production R7s?

I have a stack of tires run at various tracks (friction) with careful attention to pressures and alignment (often daily). Most are showing varying degrees of the same issue, consistent with the OP's experience.

morsini

He's never bought a new set of tires in his life. Regularly brags about how his tires have hundreds of heat cycles.

mark kibort

yes i have and they were A7s which i assume would have simlar issues, no? the little nubs should just be touched by wear.. they look new and it shows me too much camber OR too much pressure or both. so, we are talking about two different issues here. part of one issue could be over pressure.. running at near 40psi is not ideal for heavy large cars. Now, do you run a car over 3000lbs and running these sizes 295 and 315? no you dont.. i do and have been running this size for 20 years . ive modeled my pressures after the best guys running the tires, running the fastest times. i take their tires and run them for a couple more weekends, but so what. but i did buy new ones .. again, they were A7s, not R7s . is that a part of the difference that might be part of the issue. we are running 32psi hot.. Darrel anderson, one of the fastest on these tires , runs 30psi hot. So does the Driving Ambition team NSXs who also dip into the 1:29s on A7s. the some of their teammates that run the T2 mustangs are running the R7s and running 32-34psi.



sticking your foot again in your mouth. wrong and wrong. i bought a set last season for the PCA/SCCA race at laguana (first set in 18 years brand new) And, ive never said they last 100s of heat cycles. i get them with 4-5 heat cycles and run them to 9-10, from the fast guys! Darrrel anderson and his mustang rig runninig 1:29s at laguna with 3000lbs and 550hp., usually after he hits a weekend fastest time.


wow, here you go a little proof too. funny, how fake news is so common now! and guess what. buying a new set for the runnoffs too!

mark kibort

what the heck is that? the first picture looks like he ran into a wire fence and picked up a dagger. thats actually coming OUT of the tire??????.... but this one is coming from where, the bead area? never heard of this!

Texas RS

I had it happen on the inner sidewall, I didn't see it but I heard it, but not before it cut the dust boot off of my damper. I have had this happen twice, but only on tires that were remounted.

Matt Romanowski

The nubs are from the mold and have nothing to do with where the tire should wear.

Texas RS

Matt, This is a thing, I am not sure what the cause is, but I have seen it several times here in Texas. On one of mine the thread was visible and left a black mark on the fender, similar to the one shown in the picture.

schaibaa

Gear Rower

So, is this wire from the bead? Does this fail from improper mounting techniques? What the heck is going on here??

cre8fun

Thanks for input. I agree on a C7. my C5 is 3100 with fuel and me. What I find is that most C5 guys are running 28 hot, hence my 30-31 hot for a insurance.

cre8fun

yup, my alignment is almost the same.

mark kibort

From the fastest and best wearing folks out there, the wear patterns usually end up just at the nubs. its not that they are a formal indicator, its one we use. kind of like the oak tree out of the corkscrew.. aim for it, and usally it will give you a good line . if we could see the inner part of the tires, i would bet that the "nubs" are being hit. and maybe further. i have a lot of fender cam video showing some good tire action ,and it clearly shows that the tire rolls on to this section of the tire. i know if i run near 40lbs (ive forgot to air down a couple of times) the car feels like it is on ice skates.