iii. Over 1600 cc: 9in. c.
For Category 4, 5 and Vehicles competing under FIA Appendix K all wheels and tyres must comply fully with FIA Appendix K Regulations for Vehicles in Rallies.
7.2. The fitting of a dual master cylinder or any other type of device providing a simultaneous action on all four wheels and divided action on two wheels is permitted provided the original brake pedal and pivot point are used and it must be possible under all conditions, running or stationary, for 25 % minimum braking effort to be applied by the driver through the braking system to each axle. For Cars in Category 1 the adjustment of brake balance must not be possible by either the Driver or the Co-Driver when normally seated in the car.
7.3. Dampers must be in accordance with Ch. 13 App. 17 Art. 4. For Categories One, Two and Three, Monotube dampers must not have any external gas inlet ports or adjusters, including plugged or blanked-off ports or adjusters.
8. Miscellaneous
8.1. The use of gas discharge technology in any forward-facing lights either main beam or auxiliary or in any reversing light is not permitted.
8.2. Unless of the specification used in period for the specific make and model of Vehicle the use of light pods to individually mount or to mount auxiliary lights as one unit is not permitted.
8.3. Roof vents may only be fitted if of the same specification as those fitted to the particular make and model of the car in period.
8.4. Any underbody protection must be of period specification. A guard moulded closely to the vehicle floor pan fixed by bolting and / or adhesive may be fitted but must not extend beyond the front and rear axle centre lines and the outer 100mm on each side must not cover the vertical section of the outer sills
9. Stage Rally Class Structures 9.1. Refer to App. 24 Art. 1.1. All Stage Rallies must use the Class structure detailed in App. 24 Chart 50.
Motorsport UK National Competition Rules 2026 Edition 1
Chapter 13 Appendix 17- Historic Special Stage Rally Cars 509