Global Time Attack | Super Lap Battle
International Unlimited Class Rules
(2024 Edition)


Vehicles in International Unlimited are held to the standards found in Section 1 in addition to the allowances below. All Unlimited vehicles must meet the GTA Safety Minimum safety level 3 standards found in GTA Safety Minimums. Unlimited Class vehicles are required to pass a mandatory safety inspection. If the GTA officials do not feel your car is safe to race you will not be allowed to compete. For guidance please refer to the safety regulations for race vehicles as described in Safety Level 3 of the GTA Safety Minimum. This means proper fire-retardant driver’s attire, onboard fire extinguisher or fire system, a minimum of legal 6-point cage, 5- or 6-point driver’s restraint, etc. It is up to you to make sure your vehicle complies. If you have any questions, please ask. GTA Safety Minimums and General Rules.

Any questionable modifications not specifically covered within the class and overall rules must be submitted for clarification and allowed by GTA Staff. If you are unsure if your vehicle meets the regulation requirements, it is your responsibility to clarify any/all areas or points prior to an event.

International Unlimited Class Rules

Please address any technical questions to

  1. Chassis/Exterior/Aero
    1. The OEM tub chassis may be modified to accommodate racing modifications but must still retain the OEM floor pan from firewall to rear edge of front passenger area or leading edge of rear wheel arch and must also have an OEM sheet metal path from front strut/shock tower to firewall. Every effort should be made to maintain the OEM appearance of the strut/shock towers and related tub components. Questionable modifications need to be approved by GTA Staff. Please send description and pictures to for approval.
    2. Factory firewall may be modified to allow for roll cage to continue into the engine bay, for service related reasons, and for fitment of alternate engine and transmission, wiring and plumbing. These modifications are limited to the minimum required to accomplish the above and the firewall must be sealed and structural to provide an adequate level of safety in the event of an engine bay fire.
    3. Composite or alternate materials may be used for external sheet metal.
    4. The OEM B pillar must be retained but may be moved to aid driver entry/exit.
    5. Lower frame may be modified for fitment issues. Lower frame rails are also permitted to be removed no further than the centerline of the front shock towers. Modification to the lower frame rails should be first submitted to GTA officials for approval.
    6. Leading end of rocker panel, floor pan and firewall may be modified for tire clearance or aero benefit.
    7. Custom or modified front and rear sub frames may be used.
    8. Top chops on coupes/sedans may be no more than 3”. Windshield frames on convertibles may be removed and alternate cage design may be used.
    9. Full undertray/ flat bottom is permitted.
    10. Body modifications/materials are open, provided the basic silhouette of the original car is largely maintained.
    11. International Unlimited cars may run in with drivers and passengers windows up or “installed” provided they have provisions for being easily opened or knocked out by both the driver from the inside and safety personnel from the outside, and there is fire suppression installed.
  2. Engine/Drivetrain/Fuel
    1. Driveline changes are unrestricted. It is legal to change the drive wheel configuration. The vehicle would then compete in the drive wheel configuration class that the finished vehicle is now eligible for.
    2. Nitrous oxide is permitted with appropriate blow-down tube and mounting.
    3. OEM and aftermarket Hybrid and electric drives are allowed and open to modification.
    4. Any fuel may be used; if methanol is used in 100% form GTA staff must be notified.
    5. The engine may be moved up to 12” in any direction.
  3. Suspension/Brakes/Tires/Wheels
    1. Tire brand is open. We allow DOT tires or Racing Slicks.
    2. Suspension type changes are open provided they retain the OEM front strut/shock towers. They may be clearanced and strengthened. Pushrod and remote type suspension is allowed.
    3. Any brakes and wheels are allowed.
    4. No part of the top of the flat tire tread may protrude past the widest point of the wheel arch/fender/quarter panel or flare when viewed from above at the wheel centerline.
  4. Interior/Roll cage/Safety/Misc.
    1. A six-point roll cage with side impact protection that meets GTA Safety specs level 3 or international equivalent is required.
    2. International equivalent safety must be pre-approved by GTA.
    3. All vehicles must have a fire extinguisher or fire suppression within reach of the driver as per GTA Safety Minimums.
    4. All vehicles are required to have front and rear tow hooks.