Technical Regulations

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Technical Regulations – General

The 2016/17 Radical Cup Series is for Radical SR3 Sportscars complying with FIA Appendix J Article 277, these technical regulations, and the car specification published by Radical Sportscars incorporating FIA Dossier ST-09-06 dated 14/07/2010 in all respects. Other Radical cars may be permitted to race at the sole discretion of the Organisers but will be subject to a performance equaliser additional pit stop penalty as determined by the Organisers.

The following Technical Regulations are set out in accordance with standard principles and it should be clearly understood that, if the following texts do not clearly specify that you can do it, you should work on the principle that you cannot. Therefore everything that is not specifically authorised and anything not specified in these regulations or any series bulletin is strictly forbidden.

Each Radical model is manufactured to an identical class specification. In the interests of fairness and safety, competitors may not depart from this specification under any circumstances, other than as specified below.

All Radical parts must be supplied by Radical Sportscars or its appointed distributor and fitted in their original position and as supplied, unless specifically stated in these regulations. Parts may only be fitted to the appropriate model.

Whilst the Technical Delegate is empowered to check all competing vehicles for compliance and has been provided with the data to determine the continuing eligibility of each car, the onus of responsibility for the eligibility of vehicles competing in this Series, rests with the entrant/Competitor. In the event of a dispute concerning the compliance of a vehicle with these Regulations, the onus will be on the Entrant/ Competitor to satisfy the Organisers with regards to such compliance, and NOT the organisers to prove non-compliance.

Tests to establish the power output of any car may be carried out by the Scrutineers at premises agreed with the Organisers. The transportation of the car and the costs associated with same will be borne by the entrant. Such power testing will be carried out using rolling dynamometer equipment operated in accordance with the equipment manufacturer’s instructions.

Where it is suspected that a component or structure fitted to the competing vehicle may render the vehicle ineligible under these regulations, the component or access to the component will be sealed by the Technical Delegate for subsequent examination. Where ineligibility is subsequently proven, all points accrued by the competitor from and including the date of sealing the said component, to the date of the examination, shall be forfeit.

Where costs are incurred as a result of any eligibility check, as may be reasonably requested either by the Technical Delegate or the Series Organisers, these will be borne by the competitor .

As a method of control, any component on a competitor’s car may be removed by the Technical Delegate and exchanged for a similar component provided by the Series Organisers. This includes the ECU. Whilst efforts will be made to ensure that the condition of the exchanged parts is similar, responsibility for the care of exchanged components lies with the recipient. Exchanged components may be returned on completion of the race.

The 2016/17 Radical Cup Series is a ‘single-brand’ race series, for competitors participating in the Radical SR3, SR5, SR8, RXC cars as specified herein.

  • SR8 2.6 litre V8
  • SR8LM 2.8 litre V8
  • SR8 2.7 litre V8
  • RXC Turbo and RPE Engine
  • RXC Spider Turbo and RPE engine
  • SR3 RS 1500 Supersport 2009 build or later
  • SR3RSX 1500
  • SR5 2.0 litre
  • Open to all 1500cc K7 powered Radical SR3 cars built before 1 January 2009 and Radical SR3 cars fitted with 1340cc engines
  • A Radical that does not fully comply with the technical regulations may be permitted to run at an event. Participation in the races will be at the sole discretion of the Organisers. Participants in such cars maybe subject to a performance equaliser penalty in the form of an additional pit stop time which is determined by the Organisers.


General Technical Requirements and Exceptions

DEFINITIONS: All references to standard parts and or materials in these regulations shall be taken as being the Radical Sportscars original specifications and drawings. In all cases of dispute, query or clarification or ruling these drawings and specifications shall be regarded as fact. All parts listed in the Radical 2014 International Order Forms are eligible respective to car type unless otherwise indicated in these regulations.


  1. Chassis
    1. Powder coated tubular steel space frame chassis with aluminium panels and integral roll over bar completely standard and unaltered. This includes thickness of panels and rivet spacing.
    2. Towing Eye Towing eyes must be fitted conforming to FIA Appendix Art 259.14.6
    3. An FIA approved collapsible crash box structure supplied by Radical Sportscars must be fitted to the chassis during Series events.
    4. All Radical Models are manufactured to a standard specification and may not be altered.
    5. All chassis repair work must be carried out by Radical Sportscars Ltd.
  2. Bodywork / Aerodynamics
    1. Any aerodynamic device manufactured by Radical Sportscars for the particular model, listed on the Radical 2014 international order form may be fitted as supplied, i.e. front splitter, front diffuser, dive planes, single plane rear wing, double plane rear wing, rear diffuser or roll bar fairing.
    2. The minimum ground clearance is 40mm. Under no circumstance can any part of the bodywork, or of the suspended part of the car, be below a horizontal plane passing 40mm above the ground, the car being in normal racing trim with the driver aboard. A gauge of 40mm may be used by Scrutineers before or after races or practice to check the ground clearance.


  1. Engine
    1. All engines shall be prepared and sealed by Radical Performance Engines for Radical Sportscars Ltd. All repairs and rebuilds must be undertaken by Radical Performance Engines.
    2. The starter, generator and ignition system must be fitted as standard
    3. All competitors who have previously raced in the Radical events must have all out of season engine work carried out by Radical Performance Engines before the Series commences.
    4. Competitors not having out of season work carried out will have their engine seals inspected by the Technical Delegate prior to qualification for the first event.
    5. Once registration for the Radical Cup Series has been accepted ALL engine work for the duration of the Series must be carried out by Radical Performance Engines.


  1. Cooling System
    1. The oil and water radiators as supplied as standard by Radical Sportscars must be retained. It is permitted to blank off the radiator to control the temperature.
    2. heating of oil and water is permitted.


  1. Induction System
    1. The entire induction system including carburettors/injector system must be standard for the engine. The standard air box and filter as supplied by Radical Sportscars must be retained and used.


  1. Exhaust System
    1. The exhaust system including silencer must be standard as supplied by Radical Sportscars.
    2. Exhaust wrapping is not permissible.


  1. Ignition System
    1. The standard Radical Sportscars ECU must be retained. It is not permitted to reprogram the ECU. The Technical Delegate will on a regular basis supply a replacement ECU, which the competitor must change on request.
    2. The ECU must be located in the position as supplied from the factory. Heat shielding the ECU is free but it must not restrict removal when required.


  1. Fuel Delivery System
    1. The standard fuel pump as supplied by Radical Sportscars must be retained.
    2. Heat shrink or heat insulation of fuel lines, wiring loom and wires may be fitted. This must be easily removable for inspection, if required.


  1. Suspension
    1. All cars may be fitted with AVO or INTRAX shock absorbers supplied by Radical Sportscars. No internal modifications are permitted.
    2. Spring rates front and rear are free. Alternate front anti-roll links and rear anti-roll bars as supplied by Radical Sportscars, may be used.
    3. The front and rear suspension is double wishbone. The front and rear suspension is fitted with the unique Nik-Link anti-roll system.


  1. Transmission
    1. A separate gearbox catch bottle must be located near to the gearbox breather and connected by a braided hose on all SR8 (SR8LM) cars.
    2. The Radical Pneumatic paddle operated shift system may be fitted.
    3. The reverse drive system as supplied by Radical Sportscars must be retained and operational by the driver when seated in the driving position at all times.
    4. The final drive system must be standard as supplied by Radical Sportscars. Drive ratios may be adjusted by changing sprockets/gears supplied by Radical Sportscars.


  1. Exterior Lighting
    1. Cars may run with or without the full lighting kit supplied by Radical Sportscars.
    2. Headlight covers must be fitted in either case. Brake lights must be fitted and in working order and must not be wired in a way that allows them to be switched off.


  1. Battery
    1. An electrically powered starter motor and battery are mandatory and must be operable by the driver when normally seated and capable of repetitive starts.


  1. Alternator
    1. Must be standard as supplied by Radical Sportscars, and be in working order.


  1. Data Loggers


  1. Data loggers supplied by Radical Sportscars are permitted, however these will be used for drivers’ guidance only. Official times will be provided by the official timekeeper. The fitting of a transponder is mandatory. The Radical lap timer, as supplied by Radical Sportscars may be fitted. This, however, will be used for drivers guidance only. Official times will be provided by the Official timekeeper. The Technical Delegate shall have access to data loggers and data logger equipment, upon request.


  1. Electrical cut off switch marking
    1. An additional sticker must be placed on both outer sides of the cockpit to clearly identify the location of the electrical cut –off.


  1. Brakes
    1. Radical 4 pot calliper front and rear
    2. Vented 260mm diameter discs or optional 280mm (SR3) and 300mm (SR8) floating vented discs supplied by Radical Sportscars. Only colour coded brake pads supplied by Radical Sportscars may be fitted.
    3. The fitting of a cockpit adjustable bias adjuster as supplied by Radical Sportscars is permitted.
    4. A mesh screen supplied by Radical Sportscars must be fitted across the brake duct apertures on all cars to prevent ingestion of grass and debris to the brake ducts.


  1. Wheels and steering
    1. All cars shall be fitted with wheels as supplied by Radical Sportscars.
    2. Steering wheel diameter may be changed to suit driver’s preference, and must be supplied by Radical Sportscars.


  1. Tyres
    1. Dunlop tyres as supplied by the Radical appointed tyre distributor.
    2. Where necessary, alternative tyre compounds may be specified by Series bulletin.
    3. A maximum of 4 new slick tyres may be used per round after the start of qualifying. Wet weather tyre quantities are unrestricted. Serial numbers from these slick tyres must be declared on the Radical Series Tyre form. Top copies of the form are to be


  1. retained by the team/driver and the bottom copy must be handed to the Technical Delegate prior to the start of each qualification.
  2. Should a competitor require an additional tyre(s) during a round and the Technical Delegate deem a tyre(s) unsafe for racing the competitor is permitted to purchase a replacement tyre(s). If the replacement tyre is new and puts the competitor over his/her permitted tyre allocation then for the following race he/she will forfeit 5 Series points per tyre over and above the allocated number.
  3. The use of tyre heating equipment/heat retention devices, tyre treatments or compounds, is prohibited.


  1. Weight
    1. All cars may be weighed during Parc Ferme – after qualification and again as required by the Technical Delegate, after either or both of the races.
    2. Cars will be required to meet the minimum weights, as weighed on the Series Scales as provided by the Organisers. These scales will be identified and have a valid calibration certificate. Other scales may be nominated from time to time with the agreement of the Stewards.
    3. Minimum weight for Radical SR3 is 690 kg.


  1. Fuel tank & fuel
    1. Standard tank (FIA Fuel Cell) as supplied by Radical Sportscars must be retained.
    2. Competitors are only permitted to use pump fuel with an Octane rating of 98
    3. Each car must be fitted with a Radical Fuel testing ‘T’ piece plus a Radical dry break valve fitted to the fuel line to facilitate safe fuel testing.


  1. Silencing
    1. Not used


  1. Decals
    1. Club and sponsor decals will be available at the first event at which the car is entered.
    2. One complete set of decals including numbers and number backgrounds, will be supplied to each team on receipt of completed registration form, and before the first race, FOC. Any subsequent numbers or number backgrounds will be charged according to the latest Radical price list.
    3. Sponsor decals are to be positioned as per drawings available from the Series Co-ordinator. (See Appendix I)

Failure to comply will render the car ineligible.


  1. Subject to Sponsor requirements, each Competitor may be required to have the official Radical Cup Series woven badges, sewn onto their overalls at all times during the event. The exact position of these badges shall be at the discretion of the Series Organiser and will be communicated to each competitor by Bulletin at a later date.
  2. Badges are required to be in the correct location without alteration and without interference.
  3. Notification as to whether this clause will be activated will be notified to competitors not less than three weeks before the first event.


Appendix I (See Cl 22)


Space reserved for Series sponsors.

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