The first time we slapped on some Yokohama ADVAN A052 tires on our Ford Fiesta ST we took first place at an autocross. Obviously, we were extremely happy with that result, however, to become a champion you can’t sit on your laurels. You always have to search for more speed, because your competitors are certainly chasing opportunities as they look to knock you down off the top of the podium. It was time for us to fine tune our Yokohamas.
The first thing we did to try and improve our times was ensure we were running the optimal internal tire pressure for the Yokohamas. We evaluated our increasing tire pressure with each run, as well as tire temperatures, using a combination tire gauge/pyrometer. We collected data and used a spreadsheet to evaluate how the tire heated up and increased pressure during multiple autocross runs We also evaluated where the temperature was increasing across edges and the face of the tire. The end result was we found the Yokohamas liked to run fast at over 40 psi.
As we worked with the tire pressures we also completed a tire test comparing multiple sizes of the Yokohama ADVAN A052 for TURNology. Once we determined the fastest set for the Fiesta, we stuck with that tire size and then evaluated what sort of alignment changes the car needed to help optimize that specific size of tire. The heat data from the pyrometer indicated the outside edge of the front tires was significantly higher than the inside edge. This meant we needed more negative camber.
At our Double Nickel Nine Motorsports shop we added some negative camber to the FordMuscle Way of The FiST project car and headed back out onto the track. We would have preferred to add even more negative camber, however in the SCCA Street class we were limited to the type of modifications you can make to the car. We were able to get 1.3 degrees of negative camber for both front tires within the stock legal adjustments.
With the added negative camber, the Yokohama ADVAN A052s really brought the speed to the little Ford Fiesta. The car was more neutral in handling and certainly had more grip with the front tires. We were able to zip through slaloms more aggressively, lowering our lap times compared to our competitors.
The results were a success, winning the SCCA H-Street class at multiple autocross events. The Yokohama tires were holding up great, providing lots of stick when we needed it to help us cross the line faster than anyone in our class. Using the PAX results (an index of autocross results across all classes) we were able to determine if our car on the Yokohamas was improving overall. Each time we had taken the car out we were usually in the top 10, often in the top 5 for PAX results. After making some minor alignment changes and pressure adjustments we took second place overall at an event.
A lot of people were coming up to us at the autocross events to discuss the new Yokohama tire. The improved performance of the Fiesta ST was getting people’s attention in the paddock. We were the only car using the new tire and we had just finished second overall out of the entire event. Some people had concerns that they had heard the Yokohama ADVAN A052 was too soft and wore too fast. Our opinion was that if you wanted the fastest 200-treadwear tire in autocross it has to be softer and wear quicker. That wear is the car gripping the track and taking away layers of rubber to ensure your car crosses the line first.
Our progress report for this point in the race season competing on the Yokohama ADVAN A052 tire is all thumbs up. We haven’t lost a race yet and have consistently been in the high rankings of the PAX index regardless of which club or chapter we have raced with. We are all set and registered to attend the 2020 Tire Rack Solo National Championships in Lincoln, NE, in September. Hopefully the FiST combined with Yokohamas can bring us home a good finish.