Note:Text changes from the previous issue of this Schedule are highlighted. Text changes for grammatical and/or formatting reasons are not highlighted.
Retrospective Specials and Replica Regulations
Objectives: This Schedule is designed to provide a set of regulations for the use of period based retrospective specials or replicas constructed to create a vehicle similar to (in the case of retrospective specials) or in as close as possible to authenticity (in the case of replicas) of historic, classic or thoroughbred vehicles that participated in motorsport events in years past.
Refer to Part Three of this Appendix for details on the Certificate of Description and for details on vehicle classification.
Note:The onus of proof relating to the appropriate vehicle Certificate of Description classification rests entirely with the competitor.
The date assigned to a vehicle by a COD or from corroborated information supplied by the competitor representing the vehicle’s owner shall be determined first by the age of the engine (year when that particular model and specification of engine cylinder block and cylinder head assembly commenced), or if the technology of other performance enhancing parts of the car, such as the design of the chassis, suspension or wheel and tyre assembly is of a later period, then that later period shall be used in determining the group classification.
Once classified, cars may only be re-classified by order of MotorSport NZ. It is the entrant’s responsibility to prove the eligibility of a car’s specifications as entered on the Certificate of Description.
Any appeal or enquiry regarding classification status shall be referred to MotorSport NZ.
Interpretations and Definitions: In addition to the interpretations detailed in the National Sporting Code Article 2, Schedule K Section One Article 2.1 and Schedule T&C Article 2, the following apply to this schedule;
“Group Classification” or “Period Specification” means the proven configuration of the model, as it existed in the period in which it is classified. (Refer Schedule K Section One Article 2.1 for a detailed interpretation and definition), and
“Retrospective Special” means a car built for racing events which by its design, silhouette and manufacture has created a vehicle that could have been first manufactured in a previous era. The car must comply with Article 3 of this Schedule, and
“Replica” means a car built with the intention of replicating a vehicle that existed in any one of the period classifications. The car must comply with the applicable Articles of Schedule K as if it was an original historic vehicle.
Retrospective Specials or Replicas shall be issued with; A Certificate of Description that establishes an era (Period Grouping) as to when a vehicle of the type it represents could have been first constructed.
Group classification shall be determined first by the age of the engine (year when that particular model and specification of engine cylinder block and cylinder head assembly commenced), or if the technology of other performance enhancing parts of the car, such as the design of the chassis, suspension or wheel and tyre assembly is of a later period, then that later period shall be used in determining the group classification.
Replacement parts for, and modifications to, these cars are limited to period specification except where required by;
For pre 1978 period classification vehicles Schedule AA, or
The onus of providing proof of eligibility remains the responsibility of the competitor.
Scrutineering Audits: These will be conducted to the requirements of Appendix Two Schedule A or Schedule AA for pre 1978 period classification vehicles.
Chassis: The chassis must be of a type used during or prior to the period of classification claimed. New stressed members must not be added unless this was a period specification.
Suspension Front and Rear:
The springing medium and wheel location must be of a design used during or prior to the period of classification claimed.
Anti-roll bars and telescopic shock absorbers are only permitted if they are of a type available in the period specification claimed. Aluminium bodied and/or gas filled telescopic shock absorbers may only be fitted to cars of a type whose period specification allows them.
Adjustable spring platforms may be used on all cars of a type which the period specification included concentric coil spring/shock absorber units. By the word “coil” is meant one(1) complete turn of a spiral, not a complete spring.
Rose joints may only be used if of a type available in the period specification claimed. Rose joints may be used on anti-roll bars providing that the geometry of the suspension is not affected.
Beam and live axles should be of design or type available in the period of classification claimed.
The bore of the engine must not be increased by more than 1.2mm compared to the period specification claimed and providing that the resultant capacity does not exceed the original capacity class of the period.
The stroke may not be altered from a dimension shown in a period specification.
Crankshafts, connecting rods, pistons and bearings may be of larger dimensions than the period specification, within the limits of the crankcase. They must be made from the same material type. The method of construction is free.
Neither the number of valve ports, nor the valve length, may exceed the engine manufacturer’s specification unless period evidence of their use is provided.
Cylinder head conversions may be used if period evidence of their use is provided.
Ignition: The ignition system must have been manufactured during or prior to the period of classification. Substitution of mechanical to electronic ignition or vice versa is not permitted unless evidence is produced to indicate that it was permitted with that particular model of engine in the period of classification.
Fuel and fuel Systems:
Mechanical fuel pumps may be replaced by electrical pumps, or vice-versa.
Carburettors, which are identical to a factory option for the engine model, are permitted.
Alternative carburettors from the same or an earlier period may be used, but only if the alternative components are of the same number and general type and principle of operation as those originally fitted.
Cars with fuel injection may be converted to carburettors of the same period.
Fuel injection and/or supercharging may only be used on an individual car that used it in the period and only the original system may be used.
Lubrication: It is permitted to change the system of engine lubrication (for example from wet sump to dry sump), if the period specification claimed allows.
The number and type of oil pumps used and the length of oil piping must conform to the period specification.
Engine oil coolers may be fitted but must be positioned so as not to change the silhouette of the vehicle bodywork from that style representative of the period classification claimed.
Automatic transmissions, overdrives and additional forward speeds are not accepted, unless they were available in the period specification claimed.
When an alternative gearbox is fitted, only a gearbox of the same or an earlier period will be permitted.
Rear-engine cars may utilise the Hewland Mk8 gearbox provided that the replacement gearbox has the same number of forward speeds to that available in the period classification claimed.
Final Drive: Limited slip differentials may only be fitted if available in the period specification claimed. Cars so fitted may only use Salisbury friction or ZF cam type limited slip devices.
Brakes: Brake components must be entirely to the period specification claimed except for the following;
Conversion to a different mechanical system or hydraulic operation is permitted if a period specification.
Disc brakes (similarly ventilated discs and four(4) pot callipers) are only permitted if a period specification. However if disc brakes are substituted for drums on what is otherwise an earlier period vehicle then the vehicle will assume the classification period that pertains to the period of the disc brakes used.
Hydraulic braking systems may be converted to dual circuit operation, which provides simultaneous operation on all four(4) wheels via two(2) distinct hydraulic circuits.
The installation of an air box around disc brakes for cooling purposes is permitted.
Hydraulic fluid lines may be replaced with “Aeroquip” type piping.
Steering: A steering wheel of different diameter and style to period specification claimed may be fitted.
Wheels and Tyres:
Wheels: The wheel diameter and rim width must be of a size available during the period of classification.
For open sports racing cars the wheel and tyre assembly shall be contained within the bodywork.
Tyres: These are restricted to a tyre of a type approved by MotorSport NZ for the period of classification that reflects the era of the vehicle design as identified on the vehicle’s Certificate of Description.
Note:Refer Schedule K Section One Article 8 for further information on approved tyres.
Body: The bodywork including aerodynamic aids shall be of a style consistent with the period of classification. Material shall be free except that the type of material must be that which was commonly used during or prior to the period of classification.
Electrical system: Alternators may only be fitted if a period specification.
The voltage of the battery and of all electrical devices may be converted from six(6) to twelve(12) volts. The type, make and capacity in ampere-hours of the battery is free. If the battery is placed in the cockpit it must be securely fixed and have an insulated, leak proof cover.
Wheelbase, track, ground clearance: All parts of the sprung mass of the car must have a minimum ground clearance of 60mm such that a block of 800mm x 800mm x 60mm may be inserted beneath the car from any side. The ground clearance will be measured without the driver and, if necessary, with empty fuel tanks, but with the wheels and tyres to be used in the competition fitted.
Weight: The vehicles minimum weight will be specified by MotorSport NZ at the time of the issue of a Certificate of Description or in the MotorSport NZ vehicle logbook notation.