Which part of your race car talks to you more than those four blackdoughnuts? They may not look like much, but they have a lot to say abouthow your car is handling. Teams that know how to take advantage of thefeedback the tires provide have a distinct edge over those teams that donot.
Do you start a race with lower pressure in your tires, in hopes ofbuilding heat after a few laps? If so, will you experience excessivewear in the process and risk a failure? Understanding the tires' roleand how to manipulate it to your advantage is critical to the setup andoverall performance of your race car. We spoke with Race Tires Americaand Shanon Rush and Craig Cowan of Hoosier Tire to find out the top tipson what every dirt track racer must know about dirt tires.
This tip may seem obvious, but a lack of attention to air pressure cansignificantly affect your race car's performance. According to Cowan,air pressure significantly determines dirt tire characteristics.
Air-pressure adjustments are...
Air-pressure adjustments are the easiest way to affect changes (good orbad) to your race car's handling.
"Because they are bias-constructed, air pressure determines the majorityof the spring rate within a tire. Therefore, it is imperative that tiresare treated just as any other part of the car setup," he explains. "Toomuch air pressure generally makes the car loose off the corner, whiletoo little air pressure gives the car a tight feeling on entry. Unlikeasphalt tires, it is not as crucial to balance tread wear across theface of the tire with air pressure. Concentrate on using air pressure toaffect the behavior of the car, not the tread wear."
The task of compound selection is complicated when you consider trackconditions and driver preference for a particular compound.
"This is by far the hardest part of tire management to master," saysCowan. "Selecting the proper compound depends so much on reading theracetrack and knowing what your driver likes; it often takes years tofind the proper combination."
According to Cowan, it's smart to begin with the basics: one soft, onemedium, and one hard tire. When the track is greasy, wet, or cold, runthe soft tire. Switch to the medium tire when the moisture disappearsand gives way to dry, slick conditions. When the dust is gone, so is themedium tire, so bolt on the hard one. Once you have a handle on thethree types, check out the in-between compounds for certain clay typesor wear patterns. Most importantly, take good notes on your choices tomake the selection process easier the next time.
"When in doubt, don't be afraid to ask the local tire dealer or trackchampion for their recommendations," he adds.