Spec Tire Change Proposal

[Sterling Doc]

Guys, it has become clear that Toyos will not be available in any significant quantity for the near future for our class. The current, remaining shipment to Phil's Tire is held up in California, as well. I talked with John Lindsey this morning, and have been given the green light to change the tire rule for the class, for this year.

 

My goals with this, are to keep the RA-1 competitive, but allow an adequate supply of tires through the end of the year, without having to hunt them down across the country. As R-888's, and NT-01's are also made in Sendai, they alone do not meet our needs.

 

My proposal is to reference the Performance Touring rules, and allow any tire in the same "+7 points" performance category as the RA-1, with a maximum width of 225mm. Here is the relevant section quoted from the PT rules:

 

DOT-approved R-compound tires with a UTQG treadwear rating of 50 to 130 (ex. Kumho V700, Michelin Pilot Sport Cup, Nitto NT01, Pirelli PZero Corsa, Toyo R888, Toyo RA-1, Yokahama A048, etc) +7

 

This would include the NT-01, though remaining stocks of that tire are low, and it is made in the same Sendai plant. While the V700's are not available in a 15" size, the Victoracers are.

 

This should alleviate any supply issues, and keep the current RA-1's competitive.

 

Allowing Hoosier/Hankook/BFG tires would make RA-1's instantly non-competitive, and is not a good option, IMO. On the other end of things, allowing street tires get very messy (hard to define, and very broad scope).

 

One issue is that other than remaining NT-01s, none of these tires are very cheap - somewhere around $180/tire or more. I do see that the Tire Rack has Michelin Pilot Sport Cups at $130/tires, but only in a 20/55/16" size. Allowing 16" rims, still limited to a 225mm tire width, may be an option as it would open up more tires (many are not available in a 15" size), but that would need to be thought through some more.

 

This would be a one year exception, with plans to return to the RA-1's next year, providing they become available again.

 

I want to wrap this up within the next 48 hours, and the choice is ours, so give me your thoughts!

[Big Dog]

Thanks for this idea, Eric, I guess. While I read your post, I did not understand it. I am NOT a tire specialist. I do not have the slightest idea of what the proposed spec means or how to find tires that meet it. Sorry, this is NOT meant to be a negative post, rather it is an admission of ingorance.

 

I am hoping to understand what you said and what tires would be acceptable alternatives for us. Perhaps someone can simple tell us what tires we can use based on this proposed wording.

 

As for 16 inch wheels, the cost to purchase multiple sets of new wheels would be significant. I like to have 3 sets of tires mounted up. A set that I am using, a set that are used up and are used for practice, etc. and a set of new tires that I can scrub in and let sit for a week or two and start using as needed. Two sets are the minimum and then mean that I have to take a set off before using them all up so that I have a fresh, scrubbed set, ready to go. I would hope that we can find alternatives that work for our 15 inch X 7 inch wheels.

 

Thanks for taking time out of your vacation to work on this pressing issue, Eric.

 

Jim "Big Dog" Foxx

[Sterling Doc]

Options that would fit the rule, and are available in 15" sizes are the Kumho Victoracer, Nitto NT-01, Yokohama Advan AO48, R-888, and remaining RA-1's. These are available at most major race tire shops, and online.

 

Not all of these tires are available in a 225/50, so we would allow any profile (ie 45 series tires), so long as the width stays at or under 225mm. This would mean a 225/45/15 Nitto, or a 205/50/15 R-888 would be legal, for example, but not a 235/50/15 RA-1.

[b f cybronetics]

FYI a quick search on Tire Rack and the Kumho Victoracer V700 225/50/15 is $188 and Yokohama ADVAN A048 is $226 Hmm appears tire costs just went up.

[944-Spec#94]

FYI a quick search on Tire Rack and the Kumho Victoracer V700 225/50/15 is $188 and Yokohama ADVAN A048 is $226 Hmm appears tire costs just went up.

 

I have experiencwe with Victoracer. It was from long ago. About 10 years in fact. The tires at the time were $128 each and the tire to use for PCA autocross and DE after the Yoko A032Rs where were falling out of favor at that time. The victoracer was a nice tire and never was shaved. By some accounts slight faster than the RA-1, but in my hands did not last as long and was a little harder to slide around. Still a solid tire.

 

It does require much lower hot pressures. I ran them about 32-33 hot. This much lower than I run the RA-1.

[Robbie]

FYI a quick search on Tire Rack and the Kumho Victoracer V700 225/50/15 is $188 and Yokohama ADVAN A048 is $226 Hmm appears tire costs just went up.

And don't bother with the A048. Yokohama themselves have admitted that their AD08 street tire has better grip characteristics than the A048.