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 Yokohama ADVAN A052s have proven to be a great autocross tire. Our goal was to optimize our car’s tire pressure and alignment to compliment the way the Yokohama tires work. (Photo by Jonathan Johnson CreatiForm Media)
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.
We continued to monitor and adjust our pressures, finding the optimal amount of tire pressure for maximum adhesion.
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.
After our latest victory we had a front wheel filled with brake pad dust from our Carbotech brake pads and tire dust from our well-worn Yokohama ADVAN A052s. The wear on the outside edge of the tire and the blue color from extreme heat indicated 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.
Here is our Fiesta ST ripping into the last curve at the SCCA autocross at Thunderhill pushing the slip angle of the Yokohama ADVAN A052 tires.
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.
This epic screen capture from our door mounted GoPro camera shows us driving over the slightest edge of the bottom of a cone (using all the track) in the slalom section of the autocross at Thunderhill.
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.
PAX results are a great way to determine if our Yokohama ADVAN A052 tires are improving our lap times – not just compared to the racers in the H-Street class, but every driver that attended the autocross. At this event (with our A052s) we were able to take second place overall out of every car that showed up regardless of horsepower, design, or modifications to those cars.
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.
Taking a look at the outside edge of the brand-new Yokohama ADVAN A052 tires (left photo) and the well-worn and heated raced version of the Yokohama ADVAN A052 tires (right photo), you can see these 200-treadwear tires do use up some rubber. We see this as a good thing, because that sticky, wearing tire helped us win races.
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.
