During my second 25 min. track session today my Pirelli Corsa 285/30/18 seems to have separated. This is on the inside of the tire, outside is fine. All the other tires are just fine. This tire takes the most load at my track, but I have always been very careful with tire pressure. The tire has about 30 sessions on it, but as you can see, is worn evenly and has lots of tread left. The guy at the track race shop is convinced it is a tire failure, and not worn out and suggests I contact Tirerack where I purchased it. Does anyone have any thoughts on the cause? The race shop guy also suggested since the other tires still look so good, to just replace this one tire. I run -2.5 rear camber, -2.9 front.

 

You may have a more serious issue than mere tire failure for the sake of being old. Re-check your camber and toe for that wheel. (I have had tires fail exactly the way yours did in the picture and in both cases it was due to too much camber in the tire.) The failure you have in the picture is quite possibly from the inside sgoulder of the tire overheating; resulting in the shoulder seperation.

 

Please keep me posted if you would. I will be running the same tires next month, not at the same camber settings as you however.

 

Well, that's scary. I'm about to run the same tires really soon (from tirerack). I guess I'll just have to keep an eye on them.

 

this is the 4th time now I am hearing and seeing bad things about corsa tires and the 1st generation I had dry rot cracked BADLY on the side wall only 3 months old so I'm unimpressed with Pirelli in this case

 

I had similar problems with MPSCs. What kind and size of wheel are you running? The 285/30/18 is a tough tire to run as it is a very small "balloon" without a lot of air supporting the sidewall. If you can fit 295/30/18s on there, I'd recommend it. You will get just a bit more air in the tire, which made a big difference for me.

Also be sure to consistently check your hot air pressures to ensure the tire isn't losing air during the run.

 

Add more air

 

ceboyd - the Corsa is very popular in our region for its combined wet/dry performance. Not known for failures of the type pictured here. Oddly enough we have seen belt failures on MPSC instead. Go figure. I have run through about 10 sets of Corsa with no problems other than they wear out eventually.

Best,

 

David - the corsa likes around 36 lbs. hot. Do you do a lot of street driving? Low pressures and a an extended highway drive cpupled with negative camber can cause that sort of problem. I melted a rear inside edge on my GT2 - bad alignment, I had neg 7 degrees!!! I should have had neg 2.4

 

Bob, The Pirelli specs recommended 30psi hot, I have been running 33r 32f hot, and they seemed to stick better than in mid thirties. I do drive 35 minutes Hwy to the track on the tires, but usually add a little air for the drive so they won't be underinflated.

I run -2.5 and the race shop guy thought I could use even a tiny bit more, as the outside tread area showed a little increased wear.

Should I just replace the one tire, or both rears, the other looks fine, but so did this one until it let go.

 

No problem here with Corsas either (nor have many others in our Region). I run about the same camber settings as you, and run them about 32-33 hot at the track. When street driven, I have at least 36 cold in the tires.

 

David,

Where did it happen? Were you on the track, if so, what corner? I was out there Saturday.

Now, I do have to agree with everyone that you should put in more air. Bruce H is running them at around 36-38psi hot and hasn't had any issues and he pushes his 3400lbs car pretty hard. I know that's what Pirelli recommends but I just don't buy it. I've talked to them a couple of times when I ran the PZero C's and from I remember, they recommended 2 bar (or roughly 30 psi) hot!!!! I can understand running their slicks that low, but not the R compounds.

George

 

George, I know it is hard to believe, but I didn't feel it happen. The car felt a little soft during my cool down lap, and my times were pretty consistant right up to the end of the session, so I can only think it was right at the end of my last hot lap. I did have a long session, about 22 laps on the 1.7 section. Yes, I always felt uneasy about going down to the Pirelli specs of 30 hot, and could never bring myself to do it. However, 32-33 hot felt better than 36-38 I had used on a couple other occasions.

Since this is my first set of R tire, and my lack of any other experience with R tires makes this whole thing confusing to me.

 

I have seen this a number of times with the Corsa. One guy had it happen on a rear a mile from his house. Used his spare, got another half mile and the other rear blew just like yours. Both blew right at the sidewall to the tread. Tires were properly inflated and had plenty of tread. I have also seen them go at track events several times. Every time it was with the 285 tire on the rear.

 

I'm glad that didn't happen at full speed on the track. Could have been messy.

George