Rules & Racecraft

First we have Parma Slotstox in pictures by Ken Holmes #13 – you'll need a soldering iron & paint – followed by the BSA Rules and then Racecraft:



Click on the links below to read the up-to-date Rules & Racecraft, or read them here.




The current BSA car specifications for ParmaStox can be found below.

NBIf these rules dont say you CAN, please assume you CANT, and then seek clarification from our Technical Committee.



  1. The car body and chassis must be an authentic scale representation of a BriSCA F1 or F2 Stock Car, from 1954 to the present day (Superstox/V8 Stox allowed).
  2. The body must be firmly attached to the top of the upper chassis and have no sharp edges.
  3. The car body must have windows cut out or clear; a painted driver is optional.
  4. Driver’s name and number must be displayed on the body.
  5. A forward facing driver number, minimum 10 mm, and side numbers suitable for race scoring, white on black or black on white, must be visible.
  6. Grade colour must be painted on the cab or on the optional aerofoil.
  7. Replica cars deviating from the above must be supported by authentic photographic evidence.


Upper Chassis

  1. Stock car upper chassis work (bumpers, main rails, nerf bars etc.) to be constructed as a single rigid component in 16swg/1.6mm/1/16” material.
  2. Upper chassis must be attached to the pan by hinging around the front axle and tethering at rear to allow 1.5mm max vertical float via a strong back hook.
  3. Any other hinged or floating chassis sections, droparms, suspension or any mechanical or fabricated device to enhance handling is not permitted.
  4. Upper chassis must extend past all points of the lower chassis pan and be symmetrical about centre line (with the exception of any front or rear guards – see diagram on page 4).
  5. Bumpers to be straight (not angled or bent) and at 90 degrees to the main rails.
  6. Main rails must be straight (not angled or bent) and above front and rear axles.
  7. Nerf bars to be at main rail height.



Lower Chassis

  1. All mechanical components and chassis must be unmodified and be symmetrical about centre line.
  2. The lower chassis pan must be either a Parma Womp chassis (brass or steel), Champion Thumper/Legend/Modified chassis, or Sprints plus brass chassis.
  3. Chassis pan width must be cut to between 28 & 36mm. You may fold up both sides of the baseplate for added strength, but the width must remain between 28 and 36mm.
  4. The only modifications allowed are:








    1. 2 longitudinal wire 16swg stiffeners soldered to top surface of pan;
    2. short 16swg wire brace between motor bracket and pan or rear axle tabs.
  5. Any ballast must be rigidly soldered or glued to the flat surface of the pan (only lead ballast allowed).




  1. The only permitted motor is the standard Parma 16D, and all previous retrospective motors (white/clear endbell, pink endbell and homeset), with the exception of the “Rotor Motor”, which is banned with immediate effect.
  2. NO MODIFICATIONS ALLOWED – this includes timing and balancing.



Only Parma, Champion or Cox 48 pitch contrate or pinion allowed.


  1. Front wheels/tyres o/d 18mm min.
  2. Rear tyre width 12mm max.
  3. Rear tyres – only control sponge tyres from club stock allowed (Parma MX or Alpha Supernatural).



Dimensions Summary

PARMA pan width             

36 mm max

28 mm min

Bumper depth

5 mm min, 8mm max, (22mm max including front/rear guard bar)

Overall length including guide

135 mm max

Bumper width (with flat vertical face)

54 mm min

Overall width

65 mm max

Ground clearance (at any point)

1 mm min

Cab height (from track)

42 mm min

Front wheels O/D

18 mm min

Bumper contact point (from track)

13 mm (at any point)

(1 mm tolerance for rear bumper with new tyres)

Rear tyres – width

12 mm max


©Ken Holmes  & Jack Branch, 2015                               Updated November 2017


See next page for a useful Ken Holmes diagram to help clarify any issues.

Any further queries? Please consult our Technical Committee.


BSA Rules of Racing

  1. All cars line-up in grade order, front wheels immediately behind the grade line. Your BSA grade is equal to your club grade. If you race regularly at more than one club, your BSA grade is your HIGHEST club grade. However, in the Grand Final of any BSA Championship cars start in one line, usually all from the blue grade.
  2. All races require a Starter (shouter), Scorer and Steward.

    1. The Starter’s job is to announce “Drivers ready?” followed by “Go” or a buzzer/bleeper which means “Go.” The Starter will then count out loud the lead car’s laps, 1, 2, 3 etc. until advising “7 last lap”.  The result is called for each car completing 8 laps in their own slot. It is the responsibility of all drivers to count their own laps, and ensure they have completed 8 before they stop in the designated area. Cars overshooting the finish line will have to complete an additional lap – unless they are the last car running (LCR), and have an unobstructed track, confirmed or declared by the Steward. (When the track is unobstructed LCR does not need to complete 8 laps.) Cars may not be removed from the track until the end of a race. A driver may choose to remove their car for repairs at the end of a race but cannot expect the Starter to excessively delay the meeting, and so may miss the next race. It is reasonable to allow 60 seconds.
    2. The Scorer’s job is to write down the race results as advised by the Starter and, if necessary, clarified by the Steward. On a 4 lane track the finishing points are 4321, 5 lanes 54321, 6 lanes 654321. Deslotted cars (including wrong lane) score 0.
    3. The Steward’s job is to monitor the race. Should a driver fail to start the Steward may order a re-start. Should a driver jump the start, the race will be re-started with the guilty driver placed 1 grade further back. Stopping anywhere on the track or deliberate forceful follow-ins will be penalised.  The penalty for both offences is a “Warning”, which will be recorded by the Scorer. A second Warning at any time during the meeting will disqualify that driver from that heat/semi/final/GN and relegate them to last place with a score of zero points from that race. A third Warning during the same meeting will null and void that driver from the entire meeting, i.e. zero points and no more racing. The Steward’s decision in any race is final.
  3. A typical format consists of 2 races in each lane for every driver. The finishing order is determined by raw points scored, as outlined in 2b above. In heats, each driver is then awarded race points (1st to 6th) of 6,5,4,3,2,1, regardless of the number of lanes. Should there be more than 6 drivers in a heat, drivers finishing 7th, 8th, etc. will all receive 1 point. Currently the top 12 qualify for the semi-finals, with the first 3 in both semis qualifying for the Final. Any ties are decided by, in order, raw points; then, if still tied, heat wins; and finally a run-off in the most central lanes. Drivers placed 4th, 5th, and 6th in the semis score a further 5,4,3 points, to be added to their heat scores. The 6 finalists score 12,10,9,8,7,6, to be added to their heat scores. Grand Nationals (if run) are separate from this and scored 6,5,4,3,2,1.
  4. To ensure optimum racing, drivers for the next race must be trackside prior to completion of the previous race – the race Starter should not wait for latecomers.
  5. All bumping, boring, and contact between cars is an expected and welcome part of the racing.
  6. Drivers may only use one car per heat (if your car is deemed to be damaged through no fault of your own, at the Steward’s discretion, a spare car may be substituted until the damaged car is again trackworthy).
  7. If your car becomes deslotted it will not be put back into its lane – it will not be touched, except, possibly, by other cars.
  8. If you are fortunate enough to be knocked back into your slot, you may continue the race.
  9. If another car is knocked into your slot there are 3 possibilities:

    1. Your car is deslotted or fails to move, you do nothing (i.e. you do not drive your opponent’s car).
    2. Your car is still in the slot, you carry on racing; your opponent’s car is officially deslotted even though it’s still going round in your lane.
  10. There must never be any shouting at, or abuse of, the officials or fellow racers. Any driver who feels aggrieved should simply make her/his point politely to the Steward, who will then decide on any action (which may be nothing). Remember, the Steward’s decision in any race is final.
  11. If, during a race, a lane stops working because of a blown fuse, this is deemed to be “hard luck” to the victim(s), and no re-run will be ordered.
  12. If a lane stops working because of a track fault (e.g. broken tape), then the track will be repaired and the Steward will order a re-run of that race.
  13. Scrutineering

    1. All drivers should get their cars scrutineered on arrival at the venue, and before taking them to the track. (This prevents low cars damaging track).
    2. The Scrutineer will inspect your car(s) and they will either pass or fail.
    3. If your car(s) fails, the Scrutineer will discreetly tell you why and may even advise you how to rectify any faults. The Scrutineer may wish to call on a member of the Technical Committee to help make this decision, but note that …
    4. The Scrutineer’s decision is final.
    5. No car will be allowed to race until it has been passed by the Scrutineer.
    6. Scrutineering can take place at any time during the meeting and, should you make any changes to a car, it is YOUR RESPONSIBILITY to get it re-scrutineered.
    7. Any car failing scrutineering (not instigated by the driver, and not caused by crash damage) during the meeting, can make no further progress in the meeting, e.g. 1, a car failing prior to a semi would keep its heat points but be replaced in the semi by the 13th placed driver; e.g. 2, a car failing at the end of a semi or prior to the final would be relegated to last place in the semi, promoting the 4th place car to the final.
    8. If a driver’s car fails scrutineering due to, in the opinion of the Scrutineer, willful transgression of the rules, that driver will be immediately disqualified from the meeting with zero points, and immediately suspended from all racing until the BSA Committee has had an opportunity to meet and decide on: guilt or innocence; and then, if appropriate, penalties.
  14. Awards!

    1. Each BSA round will carry with it a Superstar roof (see separate schedule), earned by the winner of the meeting Final.
    2. The host club will provide a minimum of 10 trophies/awards as follows:

      1. Top 6 in the Final.
      2. Highest scoring White Top (before the semi-finals).
      3. Highest scoring Yellow Top (before the semi-finals).
      4. Highest scoring Blue Top (before the semi-finals).
      5. Highest scoring Junior (before the semi-finals).
    3. The top scoring driver over all the BSA rounds will be the “BSA National Points Champion” – this will be recognised by an annual shield, engraved with the winner’s name and number.
    4. The top scoring Junior will be crowned the “BSA Junior Champion”.
    5. Similarly the top scoring driver over all the BSA GNs will be the “BSA Grand National Champion”.

Updated November 2017

5 thoughts on “Rules & Racecraft

  1. Bob Dupree

    Confusion ?!

    under build rules it states ""The car body must have windows cut out or clear, a painted driver, be firmly attached to the chassis and have no sharp edges.
    However in Q & A a question was asked?

    52. Must there be a driver in the model?
    Ans. 52)No"

    this is contradictorey to Rule  2

    Please  enlighten as to CORRECT RULE






    1. Rob Porter

      At a subsequent BSA meeting it was agreed to relax the driver rule. So windows are a must, but drivers are optional.


    1. admin Post author

      Hi Mike,

      although it refers to Brisca F1,F2 and superstox nobody is going to stop you doing Spedeworth V8 or Hotstox especially as many would be hard pressed to tell the difference!



  2. Jack

    Hi Bob,

    The rules are correct and current.

    The Q&A was from 2013 in response to a heap of questions raised by David Farrow at the time and has been left purely for insight as there is still some useful bits contained within. I have added a caveat now explaining it.




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