Next, you have to learn to read your tires. They are telling you a story after each run; you just have to learn how to listen to what they are saying. The first thing you should be doing after every race is monitoring the air pressure. How much did the pressure rise from the setting at the start of the race? How much did the tire pressure grow in the trophy dash compared to the heat races and the main event?
Tires intended for Sprint cars running on dirt undergo some special preparation prior to hitting the track. The one preparation process that is unique although not limited to Sprint cars is grooving. It places a greater number of cutting edges into the tires to aid in gaining grip from the dirt surfaces on which they race.
The tires may come with a tread design, but the manufacturer cannot make a tire that will work on any track on any given night. This is an area where racers will be required to develop some extra knowledge to create a groove pattern that works for them. Many racers have developed groove patterns that work with wet, sticky tracks and groove patterns that help develop grip on dry, slick tracks.
The intent of grooving a tire is to increase the amount of square edges making contact with the track as the tire rotates, consequently developing more grip. Unfortunately, the tire doesn't usually travel with the track in a forward motion. Rather, when a Sprint car is sideways, as it so often is when entering or exiting a corner, it travels at various angles to the direction of travel. With the attitude the car assumes as it is being rotated through the corner, the tire is traveling as much sideways as it is forward. It is easy to see why many racers have developed groove patterns that run at angles to the tire's direction of rotation.
The grooving process is something that any racer can learn, and there are a good number of tools on the market that make it a very simple process. They range from a simple sharp razor-blade type of tool to heated knives. The heated knives or grooving irons are the logical choice for this process because they are faster and give you a greater level of control.
Weir Schankel, of Van Alstine Manufacturing, a maker of grooving tools, states, "The racers are asking for a tool that is easy to use and gives a professional result. Durability and adjustability are what the racer is demanding." Sprint car racers are using blades that range in width from 0.125, to 0.187, to 0.250 inch. The power required to run most grooving irons is no greater than what would be required to run a 31/48-inch electric drill motor. So you will not need to have a large-capacity generator to run a grooving iron at the track.
 This left rear is obviously...  This left rear is obviously used, but the racer felt that grooving the tire would extend its usable life. It's not a bad idea, considering these tires are close to $155 each. |
 While taking tire temperatures...  While taking tire temperatures is a good idea, using your hand is not advisable. A good tire pyrometer can be purchased for less than $100, and the measurement won't burn you. You get a number you can record in your notes instead of "ouch!" |
 Checking air pressure is an...  Checking air pressure is an important job. Take your time and make sure you are doing it correctly. This young man was reading the air pressures to another team member who was recording the number on a check sheet, which is just the way it should be accomplished. |