Tire prep is the act of preparing tires in order to help them generate more grip. It can take many different forms depending on the type of racing.
- Tire additive / sauce / traction compound: many racers in on-road and off-road racing use a tire additive or "sauce" which gives their tires a little more grip. Many of these additives take time to work fully, so they will apply them for a specific period of time before a race, for example 20-30 minutes. Tire warmers can increase the effectiveness of tire additive, making them softer and more grippy still.
- Tire additive area: another dimension of tuning used by on-road racers is the area of the tire to which the additive is applied. Some drivers will use additive only on the inside or outside of the tire, rather than applying it to the whole tire to get the traction characteristics they are looking for.
- Tire warmers: as you race, your tires will increase in temperature, and at higher temperatures they tend to get a little softer and generate more grip/traction. Therefore, many racers (primarily on-road) will use tire warmers to get their tires up to race temperature before the race. They will usually heat them at a specific temperature for a specific amount of time, and they may adjust the temperature or the length of time to get the traction they're looking for. Also, tire warmers will help the tire additive to softer the tires even further than it would without it.
- Sanding: Some off-road racers sand their tires by spinning them on a truer or a drill and sanding the tread/pins down. This is typically done on smooth clay tracks where shorter tread allows the surface of the tire to make contact with the track more, thereby generating more grip. In fact, it is not uncommon to see racers sand the treads almost completely off, leaving just a hint of the original tread pattern, and this is referred to as ghost pins or ghost tread.
- Truing: Essentially the same process as sanding (above), truing is the act of shaving down foam tires to a certain size. This is typically done in on-road applications or sometimes dirt oval. By shaving the tire down, you lower the ride height of the car (although there are usually better ways to do that) but you also reduce the mass of the tires, thereby making it easier for the car to accelerate or decelerate. For everyday racing, a little truing may help, but top-level racers will true their tires down so there's very little foam left on the wheel, giving the least possible rotating mass. Naturally, this reduces the lifetime of the tire massively, so be sure you can afford more tires before trying this! Truing is typically done once, before racing on the tires, but you can do it again if the foam is not wearing evenly, for instance, if you have too much or too little camber and the tire is "coning."
- Washing: at a bare minimum, it is recommended to wash tires between races, so the bare rubber can grip on the track. Otherwise, the dirt that's stuck to the tire all you have to generate traction.