Under the Motorsport Australia Rally Commission, the Rally Working Group (RWG) have initiated a Production Rally Car (PRC) regulation change which will permit freedom to superchargers (including turbochargers) in this class.
Given the increasing costs of maintaining Original Equipment Manufacturer (OEM) superchargers, the primary objective of the RWG was to reduce cost and complexity of the sport, marking a significant benefit to the rally community competing under the PRC regulations.
As per previous PRC regulations, 4-wheel drive PRC vehicles will retain existing inlet restrictor sizes, however the restrictor size will now be determined only by the fuel type used. The exhaust manifold regulations have also changed in order to assist with the fitment of a non-OEM supercharger.
For 2-wheel drive PRC vehicles, the use of an inlet restrictor will only be applied when the size of the inlet to the replacement supercharger exceeds the OEM supercharger by more than 10 per cent, as a measure to limit the supercharger size to one that is similar to the OEM.
The restrictor size to be fitted will be based on the OEM supercharger inlet size plus the additional 10% per cent.
Additional changes to all regulations are being undertaken to align with the changes made to the Motorsport Australia National Competition Rules (NCR) for 2021. These changes will not directly affect the application of the regulations and are to ensure that the requirements of the NCR are met.Details on the new freedoms for supercharging in 2021 will be published in the Motorsport Australia; Group 3C - Production Rally Car (PRC) regulations which can be viewed here