Subject: Rain Racing Setup

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Summary:

Racing in wet weather can be challenging and intimidating.  With a little help and know how the experience can improve with these helpful setup tips.

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Tires

• Full or near full tread depth (5/32” to 6/32”) for heavy rain, standing water

• Worn tires (less than half worn 3/32” to 4/32”) for damp tracks are acceptable

 

Tire Pressure

• Start the session with “hot” tire pressure settings (17 – 19 psi).  Since there will be little heat build up the tire pressure will not grow from “cold” settings.  Higher pressure slightly crowns the tire allowing more water dissipation.  Also see TB002: Hoosier Vintage FF Tires

 

Sway Bars

• Disconnect one connecting link front and rear to allow the car to load the tires slower, making it more predictable and provide better driver feel.

 

Shock Absorber (Dampers) Settings

• If you have bump (compression) adjustable shocks, then reduce by 3 to 4 settings.  If you have triple adjustable shocks, reduce the low-speed bump (compression) setting similarly.  This again loads the tire slower, allowing it to not break away from the wet surface as easily.

 

Brake Bias

• Adjust the bias 3 to 4 turns to the rear.  Since you cannot brake as hard in the wet, less weight transfer from the rear to the front takes place and the front tires do not have enough load to handle the normal amount of braking force.  The fronts will lock too easily without this adjustment, making it difficult to steer.

 

Gearing

• Normal dry condition gear ratios are appropriate, but since speeds are lower, you may be using lower gears for longer periods of the lap.  If excessive wheel spin is encountered exiting a corner, try using the next higher gear to accelerate with.

 

Carb/Air Cleaner Protection

• If using a sealed air scoop feeding your carb, if heavy rain and lots of spray, the air cleaner can become soaked with water.  Removing the scoop or placing a deflector in front of the scoop to allow air in, but not allow water thrown up by the front tires, can remedy this.

 

SAFETY EQUIPMENT

• Face Shield – overcast, dark days call for clear or yellow tinted face shield for better visibility. Use one tear-off for misting; light rain.  In heavy rain, avoid using tear-offs, as water will get between the layers distorting your vision.

• Rain-X – or other water shedding products applied to your face shield allow water to be swept away by air velocity while at speed.  Works on the inside of the shield to reduce fogging.

• Ventilation – open any vents on your helmet to assist with preventing fogging.

• Glasses – using Rain-X Anti-Fog or even soap polished on to the lenses can reduce fogging.

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