Parts Substitution lists under the current Group N regulations is seen as an overly complicated part of the overall process that takes a huge effort to manage and is the background cause of many debates within the group N racing fraternity.
Group ND racing want to do away with this outdated process for Group ND and have adopted a far easier solution to manage going forward. We have identified key elements of a vehicles specification that are reflected in both the specific requirements and the vehicle specifications.
Vehicles built in the Group ND era usually underwent multiple parts variations by the manufacturer and policing what bits were used when and where add to the complexity of parts substitutions
Some examples of how we have incorporated this into the specific requirements are listed below
The number of ignition coils must not be altered
Limiting the number of ignition coils will potentially only effect highly modified forced induction engines and prevent a move to more modern coil-on-plug systems which, whilst common in performance road car modifications, will be visually and obviously incorrect for the period. The rest of the ignition system is free allowing for parts substitution.
Transmission must be from a production model and have the same number of forward gears
Manufacturers would enhance or completely change transmissions and gear ratios as the vehicle developed over time. A substitution listing for transmissions could be exhaustive. Quite often a gearbox from a more up spec vehicle or later model is easier to source and can easily be fitted to a lower spec or older vehicle with little or no effort but. By permitting this level of freedom but excluding the likes of a 4 to 5 speed upgrade, there is little or no performance gain, it keeps cost down but may improve reliability.
FInal Drive can not widen the wheel drive flange to flange by more than 40mm
Being able to alter the final drive assembly allows competitors to utilize readily available and relatively lower cost components. By limiting the width and not making changes to the pickup points allows for some freedom but not permit wholesale changes to the vehicle
