Following on from the previous categorisation of the GT4 Technical Standard into Open and Clubman, the previously titled Open regulations have now been retired. The replacement is called GT4 Pro, which importantly differentiates itself by removing the option for 3D Printed aftermarket chassis to be used.
The GT4 Pro cars must now use original chassis hardware, but have freedom over tuning parts in most areas. Standard 3:1 ratios must be utilised for all cars except those by Policar, where the pinion gear has become free for models running the original equipment 13,000rpm motor.
These changes are made ahead of the 2023 season where the new GT4 Pro category is currently planned to be incorporated into a new multi-class National GT championship, organised by DiSCA. The target for DiSCA is to simplify the rule set, reinforce the identity of the GT4 category being for off-shelf entry level manufacturers, and provide a technical specification that was flexible in accommodating hand-out materials for organised competition.
The changes do mean that cars built to the previous standard with 3D printed chassis are now ineligible for GT4 racing, but the hope is that the original chassis can be replaced and raced, or otherwise that any 3D Printed chassis may then be converted into GT Euroseries specification.