At LRP, the passenger side tire developed a circumfrencial blister on the tread blocks just inside the shoulder block. I would have expected this on the driver's front. Anyone else experience this condition?

Cold psi was 31 for two sessions and then 29 for the later two. At 31 psi the tires grew to 41/42 and at 29 they grew to about 38/39

 

I run Nitto NT01s and I also experience a 8 to 10 lb increase between cold and hot pressures. As to the blister, Front or rear tire? Were these new RA1s? Heat cycled before running? Shaved?
I've always been told that R compound tires needed an initial heat cycle and at least 24 hours recovery before the first hard use to prevent excessive wear and other issues. I don't know if its true or not because I always heat cycle. I've never tried without. Got a picture?

 

Not heat cycled...I was told by a few sources that the RA1s do not require heat cycling...but I wonder, and it's easy too. Not shaved, brand new. I did drive these on the car for a day of sales work including the highway commute home. The shop took my other wheels off and mounted these. So I went with the flow.

Sorry about the missing info - passenger side front, and the blocks to the inside of the outside shoulder. Greg, Onasled, feels this is collected rubber. I never thought of that one. I'll take a look tomorrow.

 

Collected rubber, could be... When they're hot they pick up everyting!

 

Toyo RA-1s do not need to be heat cycled, but you have to shave them. Street drivng will not wear them down enough. Also, while it may not seem true, a shaved r compound tire will last longer than an unshaved r compound tire on the track.

 

I had my RA1's shaved down to 4/32.
No break in period - just go out and hammer them!

 

I didn't shave these and I should have for the very reason you point out. Another mistake due to rushing