HotRod & Mini Construction Rules

1:12th scale Hot Rod and Mini

Hot Rod’s and Mini’s are a basic and inexpensive way into the hobby. As very few modifications to kit spec cars are allowed, it means racing is very equal, with performance coming from the driver’s ability rather than more expensive equipment. Due to their basic design, the cars are very robust and easy to work on, without needing a degree in RC car set-up knowledge. Kits are cheap, spares are cheap but smiles are plenty. Build rules have been introduced to not only level the playing field, but to keep costs minimal and prevent technology and cost creep into becoming the next GT12 class (i.e. very technical, sensitive to set-up and very expensive).


  • Choose from 1:12th scale GRP or carbon
    • Mardave VRX OE or HR3
    • Mardave Mini Assassin Racer
    • Kamtec 2L Hot Hatch
    • Kamtec Mini Racer
  • Older versions of these cars are permitted.
  • No modifications to the kit chassis are permitted.
  • No chassis side springs are allowed
  • Chassis side braces are only allowed if supplied with the thinner chassis kit (braces to original thickness chassis stiffness levels)
  • Ride height must be no less than 3mm and is subject to spot checks to prevent damage to the carpet – screws must not protrude chassis. The lowest point is classed as the measured ride height

    Example of a Mardave Mini

  • Example of a Hotrod


  • Choose from:-
    • Kamtec Satan Twenty, K20 or K21,
    • Mardave G2 F20 540, G2 2010,
    • Core 21, Etronix Sport Tuned 20t, HPI (Kamtec) Saturn 20t or standard Silver can may be used but may not be allowed to compete in championship events, please replace with one of the current motors above.
  • No Tamiya Torque or Sport Tuned motors permitted
  • No modifications to the motor end bell or timing – spot checks will be made to prevent cheating


  • Choose from:-
    • Mtroniks G5 Ultra RS or Viper,
    • Kamtec K1,
    • Mardave HR3, HR3X, HR3 Ultra or HR4,
  • Reverse is not permitted. Either disable via ESC or EPA on transmitter.


  • 4 cell NiMh only, no maximum mah.
  • Kit mounting only.


  • 32dp only.
  • 14t, 15t or 16t pinion only
  • 48t or 50t spur only

Wheels / Tyres:

  • Only standard kit wheels / tyre width is permitted (26mm)
  • Any Mardave, Kamtec or Contact foam tyres, any shore.
  • Steel axles only.
  • Wheel / tyres must not protrude from the body.

Body Shell:

  • Any 1:12th scale Lexan or Polycarbonate
  • Must be Hot Hatch or Mini styles. No GT12 style.

Other Requirements:

  • Water based tyre additive only.
  • Rear axle must remain solid (no diffs).
  • Rear wings are permitted but must not be wider that the body shell itself.
  • Battery placement must remain as per kit. No moving of parts in order to change weight distribution.
  • Internal foam or 3D printed front bumper.

Permitted Adjustments and Upgrades:

  • Power capacitors or booster permitted. No limit on size. 
  • Internal rear bumpers are allowed.
  • Permitted to use a part designed or bought outside the kit to attach the mandatory foam bumper to the car. This must not be a strengthening or bracing aid.
  • Kingpin brace may be used.
  • Any strength suspension spring front and rear can be used with 3D spring retainers.
  • Any size servo can be used. Any servo saver & servo mount may be used.
  • Any track rods, ball cups and balls may be used.
  • Ball races are allowed on front and rear axles.
  • Alloy Drive Hubs permitted. E.g Mardave Z Drive system or equivalent.
  • Front kick-up angle shims permitted.