Technical rules Download as PDF
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(a) The only car permitted to enter the endurance race is Scaleauto Dodge SRT Viper and in the sprint race also Scaleauto Porsche 991 GT3 RSR, Porsche 997 GT3, BMW Z4 GT3, Mercedes SLS AMG and Audi R8 LMS are accepted.
(b) It is the responsibility of the racer to ensure that the purchased Scale Auto cars are accurate, complete and without missing parts. (Including small plastic and photo edged parts.)
(c) An original example of the homologated Scale Auto car as described by Art.1.1.0 (a) will be at Technical Control as reference for the Technical Director and Scrutineers. In the case of all disputes, the judgement of the Technical Director (or race jury) will be final and binding.
(d) All of the chassis and body parts that come with the Scale Auto car as described in Art. 1.1.0. (a) must be used.
See Rules-Pictures for additional clarification.

If a part is shown in these pictures it must be on the car according to the manufacturer's intended mounting and location.
The only exceptions are as follows: Art. 1.1.3. (b).


(a) It is not permitted to modify the RTR car or white kit in any way other than those parts of free make as described by Art. 1.1.1 (b)
(b) Parts of free make are restricted to: (i) nuts, bolts, spacers and washers, (ii) the guide and guide nut, (iii) braid, braid clips & lead wires,
(iv) axles, (v) axle bearings, (vi) ballast lead weights, (vii) 3-dimensional wheel inserts, (viii) M50 spur gear, (ix) M50 pinion gear.
The different sized body suspension supports SC8126a-e are considered spacers.
(c) Scale Auto tuning parts including the carbon spring plates and rear suspension etc. are NOT permitted.
(d) Scale Auto supplies different height axle holders to allow for different riding heights, thus SC-8147a-d are all legal. It is allowed to use spacing material under the axle holders as to provide correct riding height. The adjustable rear axle holder from Scale Auto with part no SC-8121 is allowed. The carbon H-plates SC-8157C and SC-8158C are both accepted, so are the SC-8153C and SC-8154C carbon front axle carrier.


(a) The minimum weight for a complete Scale Auto car is 190.0 g at any technical inspection during an event.
(b) The minimum weight for the body with the body mounts and fixing screws attached is 55.0 g at technical inspection.
(c) The ground clearance will be measured with the guide out of play so that all four wheels sit flat on the tech block.
(d) The ground clearance under at the start of a race is minimum 1.2 mm.
(e) The ground clearance during or at the end of a race is never less than 0.8 mm.
(f) The ground clearance of the body at technical inspection and start of the race is 2.0 mm.
(g) The ground clearance of the body during the race is never less than 1.6 mm.
(h) Additional weighting of the body can only be applied to the vertical surfaces of the plastic reinforcing strips within the boundaries as shown in the picture below.
(i) The distance from the top of the H plate to the bottom of the chassis plate may never be more than 4.0 mm.
(j) Additional weighting of the chassis may only be on top of the chassis, NOT visible when viewed from below.
(k) The measure on the body width at the widest point (in front of the rear wheel arc) is maximum 88 mm mounted on the car.

1.1.3. CHASSIS

Only the SC-8003 GT3 chassis is permitted.
(a) The chassis must be assembled with screws and/or nuts and bolts using the original mounting holes.
(b) The chassis must be assembled in the exact manner and orientation of the production RTR car.
(c) The chassis' metal plate may be lightly sanded to remove burrs and sharp edges. Further it is allowed to remove burrs and sharp edges on the axle holders and on the carbon parts by light sanding.
(d) The original mounting holes can be re-countersunk to properly seat the screws flash to the bottom of the plate.
(e) The original MSC/Scale Auto logo on the bottom face of the main chassis plate must remain visible to the Technical Control.
(f) The original chassis plates, parts and metal body holders cannot be repainted or refinished in any way.
(g) The length of the guide blade cannot exceed 27,0 mm and this guide blade is the only part of the chassis that may enter the track's slot.
(h) No part of the chassis may be visible when viewing the car from above. See 1.1.6 e/ for clarification on tinted windows.
(i) Any form of magnets, except for those in the motor, are not permitted.


(a) The handout motor used is a NSR King Evo 25000 rpm (NSR part no. 3026).
(b) Soldering may only be used to attach the lead wires to the motor terminals.
(c) Motor coolers or heat dissipating products of any kind are not permitted.
(d) Only M50 pitch pinion and M50 spur gears are permitted.
(e) The gear ratio is fixed at 12:44.


(a) Only solid steel 3 mm diameter axles, front and rear, are permitted. No independent front axle configurations of any kind are permitted.
(b) Ball bearings for 3 mm axles are permitted.
(c) Front wheels must be either the standard hard rubber wheels with rims as supplied with the RTR cars or have a minimum diameter of 25.5 mm when using the RTR Scale Auto racing wheels. The Scale Auto parts SC-2715P or SC-2709P may be used to achieve the 25.5 mm minimum diameter.
(d) Each front wheel must make a minimum of 7.5 mm of contact with the tech block with the guide out of play. Front tires may be hardened and polished.
(e) Rear wheels are RTR Scale Auto SC-2421P ProComp 3 wheels with 27,5 mm OD, 13.0 mm wide. Only the Scale Auto wheels are allowed and may not be substituted with other brands. At events handout wheels and tires are supplied, the handout wheels and tire diameters may not be changed and must be used as supplied.
(f) Rear tires may not under any circumstances be treated with any kind of tire dressing, or compound or traction product.
(g) Removing dirt, dust and loose rubber particles from the tires may only be performed with a tape roll or Shellite provided by the Race Direction.
(h) All four wheels must be fitted with three-dimensional wheel inserts (with or without brake discs and calipers) correct to the car.
(No photo edged or vinyl cut reproductions are allowed).
(i) The wheels including inserts may not protrude outside of the body when viewed from above.
(j) No car can have a front spur greater than 80 mm or rear spur greater than 83 mm, measured at the widest point of the front and rear axles.
(This includes any protruding wheel inserts that may be fitted).


(a) All bodies and interiors must be painted. (Interiors with at least three different colours and bodies with at least a coat of clear paint covering the complete outside of the body shell).
(b) Fantasy liveries in the spirit of 1:1 motor sport are permitted.
(c) Three number shields (water slide or self-sticking) typical of 1:1 motor sport are required.
(d) Only the stock rear wing uprights may be replaced or reinforced with rubber parts of equal or like shape.
(e) All the cars are permitted to use the full Scale Auto Lexan window and interior kits. The roll cage from the original hard plastic interior must be refitted to the lexan interior. The interior must be full size and completely cover the view from above through the car windows. Tinted windows shall be regarded as clear and see through.
(f) Mirrors, wipers, light lenses, towing hooks, exhaust end pipes, the small aerodynamic winglets in the front are very fragile. Cars will be allowed to continue the race without them when it is obvious that they have broken off during racing and after technical inspection.
(g) No modifications of the body are permitted other than those described by Art. 1.1.6 (a-e)


Please read on the rules page for updates and rule interpretations. These will be introduced in the rulebook for the year after.
This rule set is compiled by Lars Harrysson ( and Rolf Andersen in 2014.
Latest revision is done by Lars Harrysson, Claus Henriksen, Kimmo Rautamaa and Rolf Andersen in September 2019.

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