Wearing our new Bridgestone Potenza RE-01R tires, we took another pair of STS2 victories at the National Tour and Pro Solo events at Walnut Ridge, AR. Due to low pre-registration numbers, both events were combined into one single weekend. The entire Tour was run this past Saturday, and the Pro Solo was run on Sunday. While it made for a hectic weekend, it was both enjoyable and successful for our Miata.
On Friday, we did some very informal tire testing by taking practice course runs on both our 205/50-15 Falkens and our new 205/45-16 Potenzas. The surface at Walnut Ridge is quite unique in that it’s old concrete that has a lot of exposed aggregate. Since the aggregate is mostly polished stones, hard street tires typically skate over the surface. Our Potenzas, being a bit softer than our Falkens, instead had a tendency to be able to get in and around the aggregate for more grip. As a result, the difference in performance of the two tires on the practice course was much larger than it was during our testing at Mineral Wells. Also, the practice course had a very large and long skid pad element, which played to the new tire’s strength (ultimate grip). Result? We were a full second faster on the Bridgestones!
Later, during the actual competition, the difference looked to be much less. We attribute this to the much higher percentage of transitional elements in the full courses, and the absence of significant steady state manuevers. This put the difference back to the 2-3 tenths margin we saw during testing earlier in the week. We’ll need many more data points to confirm these early conclusions, though.
Saturday morning at the Tour, we were able to eke out only a 2-tenths lead in the large class of 13 drivers. In the afternoon, however, we added another half-second to take the win comfortably. On Sunday, in the experimental “best of four runs” single-course Pro Solo, the margin of victory was 6 tenths. This makes 9 Pro Solo victories in a row for our project car!
Next up: the Houston National Tour, where we hope to do some comparison testing of the 16” and 15” Potenzas.
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