3. Sport and Tuner Category - Cooling System

You can replace your radiator with a larger one (but not a smaller one) as long as it goes in the stock locations and uses the stock mounts. You can also add water overflow tanks (called expansion tanks).

Sport and Tuner Category Cooling System - Full Rules

1. Engine cooling radiators may be replaced or added with alternate parts subject to the following restrictions:

A. Radiator core dimensions (width, height, thickness) cannot be smaller than the standard part.

B. Radiator must mount to OE radiator mounts.

C. Fluid capacity and dry weight of the radiator must be no less than that of the standard part. Installation of an alternate radiator may serve no other purpose (e.g., to allow a cold air intake passage).

D. The installation of water expansion tanks is allowed. A water expansion tank is the container which catches overflow coolant.

E. Thermostats may be added or substituted. A thermostat is a device which controls the passage of water.

F. Modifications necessary for additional radiators must be the minimum required for installation.