Rally Cars

Rallying is a kind of motor sport competition that takes place on private or public roads using customized production or specifically constructed road-legal vehicles. That motor sport discipline distinguishes from the rest by a none-circuit routes. There is point-to-point format in which racers and their navigators drive from one check point to another. Rallies may be won by pure speed within the stages or alternatively by driving to a predetermined ideal journey time within the stages.

There are 2 main types of rally: road rallies and stage rallies. Since the 60s, stage rallies have been the professional discipline of the automotive sport. They are based on driving over stretches of roads that are limited or closed for other traffic. Such rallies may vary from rough forest tracks to ice and snow, from asphalt mountain passes to desert sand, each selected to provide an enjoyable competition for the teams and a test for performance and reliability of the car. The main change over that times has occurred in the automotive technologies, drivers' professionalism and commercialisation of the sport.

The main difference between rally cars and the vehicles used in other forms of professional automotive sports is that the rally cars are very similar in design to production cars which are used for the public drive in everyday life. Really, rally automobiles are licensed to be used on the normal roads out-of-competition, though of course that is very uncommon. Surely cars for rally are adapted under the conditions, where those cars will perform. Those may vary from snow and ice to choking heat and sand, but in their basic design and specifications they are not far removed from their street model cousins. Rally cars are an important sideline for major manufacturers such as Ford, Mitsubishi, Honda and Subaru, whose advertising for their latest models often trades heavily on the successes of their rally cars.

Here are most common requirements for all rally cars.

General

  • Display 23cm high numbers on doors - these must be on a white background at least 48cmx33cm. If a white background on a white car the background must have a black border.
  • The vehicle must remain in the original configuration as supplied by the manufacturer: e.g. Front engine, rear wheel drive - unless specifically authorised by the MSA.
  • Cars must satisfy Construction and use regulations.
  • Mud flaps are strongly recommended (the blue book says how wide and how close they must go to the ground).
  • Strong towing eyes must be fitted front & rear, they must be painted a distinctive colour.
  • Must have operative brakes capable of stopping the vehicle.
  • Must not be a commercial vehicle.
  • Must have a minimum wheelbase of 183cm.

Steering & Suspension

  • Rear or 4 wheel steering is not allowed unless fitted as standard.
  • Have a continuous steering wheel rim.
  • Steering must not cause wheels to foul on bodywork.
  • Must have sprung suspension - so Go-Karts are not permitted.

Engine

  • The car must retain its original form of induction (i.e. turbocharging, normally aspirated) - unless specifically authorised by the MSA.
  • Turbos must have a restrictor (in accordance with FIA Appendix J) fitted at a maximum of 50mm from the extremes of the compressor blades. I think that this is currently 34mm diameter. Metro 6R4s must also have a restrictor and are also subject to certain other restrictions.
  • If the engine is not original it must be no more than 50% bigger (cc) than the original engine - unless specifically authorised by the MSA.
  • Positive method of throttle closing - in addition to the throttle linkage additional (visible) springs must be fitted to each throttle spindle to close the throttle butterflies in the event of linkage failure. If the carbs./injection already has a spring fitted which is additional to the linkage you do not need to fit extra springs.

Transmission

  • The transmission must be outside the passenger compartment.
  • Must have a working reverse gear.