Section 3.b. of the WRL rulebook has been updated to allow for unmodified lexan/polycarbonate side windows when paired with a Chillout system. The 2025 WRL rulebook can be reviewed in full below:
WRL-RULES-2025.1.1.pdf
GTO/GTU: Polycarbonate/lexan driver/passenger door windows may be run in factory-built GTO/GTU racecars expressly designed to be raced with door windows in place under the following conditions: (1) with conventional air conditioning system as installed and homologated by recognized professional sanctioning body; OR (2) with a freon-based or thermoelectric driver cooling system (IE: Chillout, Rini, Koolbox, contact WRL for approval of other devices) - must be installed and functional (Ice based systems are not acceptable). Cars with factory AC are encouraged to also utilize a persistent cooling system if windows are in place. Cars that wish to run door windows and meet the conditions above will take a .1 PWR modifier per installed window. Teams wishing to avoid modifier may remove lexan from windows or replace with street-car doors with window glass removed. No other material may be used to cover window areas.
GTU: Same as GTO - for cars without removable lexan/poly side windows and NO factory installed air conditioning/driver cooling as described above, windows must be removed OR a minimum opening of 8”x14” must be cut into the windows.
WRL-RULES-2025.1.1.pdf
UPDATED LANGUAGE:
GTO/GTU: Polycarbonate/lexan driver/passenger door windows may be run in factory-built GTO/GTU racecars expressly designed to be raced with door windows in place under the following conditions: (1) with conventional air conditioning system as installed and homologated by recognized professional sanctioning body; OR (2) with a freon-based or thermoelectric driver cooling system (IE: Chillout, Rini, Koolbox, contact WRL for approval of other devices) - must be installed and functional (Ice based systems are not acceptable). Cars with factory AC are encouraged to also utilize a persistent cooling system if windows are in place. Cars that wish to run door windows and meet the conditions above will take a .1 PWR modifier per installed window. Teams wishing to avoid modifier may remove lexan from windows or replace with street-car doors with window glass removed. No other material may be used to cover window areas.
GTU: Same as GTO - for cars without removable lexan/poly side windows and NO factory installed air conditioning/driver cooling as described above, windows must be removed OR a minimum opening of 8”x14” must be cut into the windows.
