Tires

Wet Weather Tires

A wet tire, also called a rain tire, is a specialised motorsport tire designed for use in wet conditions, replacing slicks when the track is damp or water‑logged. Its deep, patterned grooves are engineered to channel water away from the contact patch, reducing the risk of hydroplaning, a dangerous loss of grip that occurs when the tire rides on top of standing water instead of the track surface.

Optimal Pressures:

• Target 29.5–31.0 psi during the race for peak performance

• Ideal target under optimal wet conditions: ~30.0 psi

Operating Temperatures:

• Usable range: 30 °C to 70 °C

• Optimal range: 40 °C to 60 °C

• Peak grip: Around 50 °C

Key Characteristics & Management:

• Wet tires can overheat quickly if the track begins to dry, leading to rapid degradation and loss of grip

• Adjust brake duct openings to help control tire temperatures

• On a drying track, running through puddles can help cool the tires and reduce graining 

• ⚠ Avoid hitting puddles with only one side of the car, as the imbalance in rolling resistance and initiate aquaplaning.

• GT3 regulations allow the use of electric tire blankets to preheat the tires

• Wet blankets: Often unheated, or lightly warmed (~20–30 °C) just to take the chill off in very cold conditions

Tire Management

Lifespan

The life of a Tire can be dictated by variables such as:

• QThe amount of heat travelling through it (tires that overheat will wear quicker and conversely any tires that are too cold will wear quick)

• The number of spins, curb strikes and lockups you have (either from accidents, pressing the throttle too early or using too much curb)

• The number of laps done (The life of a tire is not infinite and will require changing at some point)

When deciding your pit strategy pre-race, it’s important to consider how your car set up deals with the above points. If the setup is stable, then you can certainly assume that it will not rely on the tires as much and thus give you the opportunity to use an overcut. If, however, the setup is one which is very unstable and requires the car to move about a lot, then this will have a negative impact on tire life and will limit your ability to run the tires for longer than those around you.

Adjustment

Start adjusting the setup from that parameter in order to make sure you have the right pressures during a race or a long practice session. 

The tire pressure analysis should look like this:

• Make sure that in dry conditions the slick tires are between 26.0-27.0 psi (hot pressures)

• Make sure that in wet conditions the wet rain tires are between 29.5 and 31 psi (hot pressures)

• Use the tire temperature telemetry to change the camber and toe configuration

• If  the tire temperatures wont get to the correct operating window, adjust the brake duct settings.
  The heat from the brakes also affects the temperature of the tires.

Wear, Graining, Blistering, Flat-Spots

Wear: Remaining tire tread of the tire segments (L=O/M/I ~ R=I/M/O)

• As you complete laps on a set of tires, they will slowly wear down. 

• Once you've used a set of tires and returned to the garage, you can see how much of the tire tread is left. 

• A new tire will have 3mm of tread on it. Once a tire reaches 1.5mm of remaining tread, it is considered worn 

• Ties with less than 1.5mm of tread will provide significantly less grip than a new tire

• At this point, it is recommended that you pit and have it replaced - over-wearing a tire can cause it to puncture

Grain: Amount of tire graining recorded during the last run. Graining is often exacerbated by low tire temperatures.

• • Tires that are too cold will be prone to graining if pushed too hard. 

  • Graining is a specific wear pattern where the tire tread does not fully separate as the tire wears down 

  • This results in small grains of rubber sticking to the tire and reducing the effective contact patch.

  • Graining is often a short-term issue, experienced in the earlier parts of a stint

  • Graining can often resolve itself as the tire heats up and begins to wear normally - but can contribute to faster tire grip fall-off

Blister: Amount of tire blistering recorded during the last run. Blistering is often exacerbated by high tire temperatures.

• Tires that are too hot will be prone to blistering if pushed too hard

• Blistering is, in effect, the opposite to graining, where the tire compound itself begins to degrade due to excess heat

• This results in small chunks of the tread lifting, and ultimately breaking away - reducing the effective contact patch

• Blistering often occurs near the end of a stint

• Blistering is considered to be far more serious than graining due to the potential of complete tire failure if left unchecked

Flat Spot: Amount of flat-spotting recorded during the last run. Caused by locking tires under braking.

• • Flat Spots are usually a symptom of too little ABS.

  • Flat-spots occur when the car locks up under braking, resulting in uneven wear to one specific portion of the tire. 

  • These flat-spots cause vibrations in the suspension

  • Once a tire has a flat spot due to braking, it is prone to lock up on that same spot on the tire in the future

  • Severe flat-spots can cause a tire to puncture