o.
Forced Induction engines must be fitted with a restrictor at a maximum of 50mm from the extremes of the compressor blades. The restrictor orifice to be to the dimensions currently in force in FIA Appendix‘ J’. Where there are two forms of forced induction fitted, the restrictor must not exceed the appropriate FIA Appendix‘ J’ dimensions. Provision must be made for fitting seals to the unit( s). A fee if £ 3.00 is payable for the sealing of turbo chargers.
p. With the exception of cars accepted under Art. 9.4. a- j a Vehicle may be fitted with a different engine, not exceeding 25 % increase of the capacity of the model, when it was supplied as original equipment by its manufacturer. q.
r.
The engine capacity of FIA R / GT cars complying with this Art. 9.4. a- j shall be limited to the current FIA Regulations.
Engine Oil Systems – Unless equipped with a closed loop system, a Catch tank of at least a one litre capacity to be incorporated in the oil breather system.
s. If forced induction is used the turbo / super charger must comply with Art. 9.4. o above. t.
The Vehicle may not be used in competition until the Competition Car Log Book / Vehicle Passport has been validated by the ASN and returned to the Vehicle owner.
9.5. Except for Classes A( Art. 9.1a) and B( Art. 9.1b) modifications are free within Vehicle Regulations. 9.6. Class A( Art. 9.1a) Vehicles must comply with the following requirements:
a.
The complete body shell, doors, boot or tailgate must be in production material, with no modification or lightening. Windscreens must comply with Art. 14.5 – 14.10 below.
b. No torque biasing, locked differentials or traction control devices are permitted. c.
d.
Interior trim and lights may be removed but standard dashboards must be retained. Additional instruments may be fitted.
All seats apart from the Driver’ s may be removed but the specification of the Driver’ s seat may be changed.
e. |
Wheel sizes are free. |
f. |
Wheel spacers are not permitted. |
g. |
Suspension operation must be as manufacturer’ s specification. |
h. |
No four-wheel drive system is permitted. |
i.
The engine block( which may be bored out) must be standard for the model of Vehicle with standard inlet and exhaust manifold. There can be a maximum of two chokes unless the Vehicle is fitted as standard with more than two chokes. Fuel injection is permitted if standard on the model.
j. A roll-over bar or roll cage may be fitted. k.
l.
The manufacturer‘ s original gearbox and axle with all internals as originally supplied for that model of Vehicle must be retained and in their original positions.
Vehicles need not be taxed or insured
9.7. Class B( Art. 9.1b) Road Rally Cars must be taxed and comply with Arts. 10 – 15.4 Stage Rally Cars must comply with Art. 9.3 and Art. 9.4 and Art. 16 Stage cars need not be taxed but for either a Road or Stage Rally Car, a current MoT, where appropriate, must be produced if applicable. Any forward-facing lights must comply with Art. 6.2. Tyres must comply with Art. 21.
10. Road Rally Cars
10.1. The Vehicle must be currently registered and taxed as a Private Car and comply with all statutory regulations as to the Construction and Use regulations( especially regarding brakes lighting tyres warning devices rear view mirrors silencers speedometers wings and windscreens).
10.2. In this section the term MODEL refers to all variants of the same family of cars. In addition to complying
Motorsport UK National Competition Rules 2026 Edition 1
Chapter 16 Part A( Autocross and Clubcross) Appendix 5- Technical Regulations
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