Stock Class Regulations

Stock Class Regulations 2026 (current as of 2025/12/17)

The stock class follows the Official Regulations, but with the below alterations to section 1-6 Modifications. Refer to the Official Regulations for all other areas.

6. Modifications (Stock Class)

Please follow the guidelines below when modifying your car. Also note that for modifications not listed, race officials will have the final absolute authority to grant or deny their use.

1. Cutting and shaving down of the chassis is not allowed. Homemade chassis are also prohibited.
2. Any additional parts are limited to Tamiya Mini 4WD, R/C Mini 4WD, and Dangun Racer parts.
3. Modifications to parts other than the body are also prohibited. However, existing holes in FRP/carbon plates and chassis may be countersunk. Shafts may be pushed through wheel holes.
4. Body modifications are limited to shaving it down, and cutting away parts which are an obstruction. Body catch parts must be used.
5. Rollers may not be used in the combinations outside of those permitted under the regulations.
(e.g. Putting plastic rings on other rollers, changing a roller’s plastic ring, using different roller sizes.)
6. It is prohibited to attach HG aluminum setting board, setting gauge and pinion puller parts onto a car.
7. Drive gears must be used in combinations permitted by the regulations. Permitted pinion gears depend upon the chassis used.
8. Battery terminal parts must be kit-standard, or Grade-Up parts installed as instructed in their manual. Soldering and use of double terminals is not allowed.
9. Modifications must not pose risk of hand injury or track damage. Grease must not be allowed to dirty the course.
10. Batteries must be installed in the correct polarity and direction.
11. Plates must be securely fitted. They must not wobble.

Stock Class FAQs

Theme	Question	Answer
Motors	Can I use Dash motors?	Yes.
Motors	Can I use parts from disassembled motors?	No.
Bodies	Can I use clear or polycarbonate bodies?	Yes.
	Can I split bodies into multiple pieces?	No. The only alterations permitted are shaving bodies down or cutting away parts that are an obstruction to parts.
	Can I cut away sections that obstruct chassis attachment, in order to move the body onto a different chassis?	Yes.
	Do I have to attach driver figures and rear wing parts?	No, you may remove them.
	Will I be disqualified if a driver figure falls off during a race?	No.
	Will I be disqualified if body parts (wing, etc.) fall off during a race?	No.
	Do I have to cut off all unused parts from a polycarbonate body?	You must cut your body as instructed in the kit manual.
Chassis	Can I reverse chassis direction?	No.
	Can I make new screw holes?	No.
	Can I countersink existing screw holes?	Yes
	Can I drill through screw holes or widen them to 2mm?	Yes.
	Can I use combinations of chassis and A parts that are not specified?	Yes.
	Can I race without the battery holder attached?	Yes.
Ball Bearings	Can I use ball bearings?	Yes.
Tires / Wheels	Can I combine tires and wheels of different sizes?	Yes.
Tires / Wheels	Can I replace the ball bearing in bearing rollers?	No.
Rollers	Can I use rollers which have worn down to a smaller diameter?	Markedly small rollers are forbidden. Follow staff instructions at inspection.
Rollers	Can I replace the ball bearing in bearing rollers?	No.
FRP & Carbon Plates	Can I reinforce plates using cement?	Yes.
	Can I cement multiple plates together?	Yes.
	Can I use carbon plates?	Yes.
	Can I attach plates loosely?	No.
	Can I taper down plate edges?	No.
Mass Dampers	Can I widen mass damper holes?	No.
	Can I use mass dampers whose holes have widened through use?	Markedly oversized holes are forbidden. Follow staff instructions at inspection.
	Will I be disqualified if a mass damper with ball connectors falls off during a race?	No.
General	Can I use discarded sprues or offcuts from polycarbonate or clear bodies?	No.
	Can I use Mini 4WD Car Catcher parts on my car?	No.
	Can I heat brake sponges to alter them?	No. This is dangerous and strictly forbidden.
	Can I cut brake sponges?	Yes.
	Can I cement shafts into gears?	Yes.

Information is current as of December 19, 2025

Stock Class Regulations

Stock Class Regulations 2026 (current as of 2025/12/17) The stock class follows the Official Regulations, but with the below alterations to section 1-6 Modifications. Refer to the Official Regulations for all other areas.

Stock Class FAQs

Stock Class Regulations 2026 (current as of 2025/12/17)

The stock class follows the Official Regulations, but with the below alterations to section 1-6 Modifications. Refer to the Official Regulations for all other areas.