14.3. Historic Rallycross vehicles must comply with the regulations below and Rallycross Vehicle Technical regulations( Arts. 1- 12.11) with the exception of Engine( Art. 3).
14.4. Cars Eligible
14.4.1 Must have been Homologated or be a model commercially available before 31st December 1991.
14.4.2 A validated Historic Rallycross Vehicle Identity Form( HRXVIF) must be obtained from the ASN and presented at scrutineering. This will be the definitive document for the technical specification of the vehicle for which it has been issued. The HRXVIF will remain valid for a period of 10 years from the date of issue or such time as the registered owner of the vehicle changes if earlier.
14.4.3 Vehicles manufactured after the appropriate date may be permitted, providing that documentary evidence is submitted to the Motorsport UK with the identity form to show that the specific car( not model) is of the same specification as one manufactured within the specified period. This evidence will include any technical documentation supplied by the manufacturer, documents relative to the vehicle, and any other details from reliable and authenticated sources as may be available. On receipt of satisfactory evidence the ASN will issue an Historic Rallycross Vehicle Identity Form which must be presented at scrutineering.
14.5. Permitted Modifications
14.6. Engine
14.5.1 Only period modifications used in Rallycross on the particular make and model of Vehicle are permitted.
14.5.2 They should be detailed on the Historic Rallycross Vehicle Identity Form and duly ratified by the ASN.
14.5.3 In all cases the onus of proving a modification as being period rests with the Competitor who must submit the required documentary evidence.
14.5.4 Exceptionally the ASN may grant a dispensation to use non-original parts, parts from a different model, or parts from a later period, provided that the use of these parts does nor confer an advantage in either performance or reliability. The ASN will consider written requests from Competitors who are unable to source vital components.
14.6.1 The engine is free but the block must be from a Series Production or FIA homologated engine and must have the same number of cylinders as the original engine for that model. The engine must be located within the original engine compartment. Twin engine configurations are not permitted unless homologated in that form.
14.6.2 Standard Wankel units are considered as three cylinders, twin Wankel units as six cylinders.
14.6.3 Be equipped with a positive method of throttle closing in event of linkage failure, by means of an external spring to each throttle spindle.
Motorsport UK National Competition Rules 2026 Edition 1
Chapter 16 Part B( Rallycross) Appendix 10- Technical Regulations 597