🏁 Official Mini 4WD Tournament Rules & Regulations

1. Machine & Body Specifications

Chassis Requirements: Must be genuine Tamiya. Hollowing, custom cutting, or home-made chassis fabrications are strictly prohibited. The chassis must be utilized in its intended direction (reverse chassis configurations are illegal).

Body Requirements: Plastic, Polycarbonate, or PET bodies are permitted.

Approved Third-Party Bodies: The Jiepen AE86 body is explicitly permitted. Other non-Tamiya bodies must be presented to and approved by the Race Committee on race day prior to inspection.

Trimming: Polycarbonate and PET bodies must be cut along the manufacturer's specified instruction lines.

Securing: Bodies must be securely locked at both the front and rear using genuine Tamiya body catches. If a body detaches during a heat, the machine will be disqualified for that run.

Aesthetics: Unpainted bodies, bodies without stickers, or bodies deemed too minimal to verify finishes are prohibited. Custom-made bodies, standalone wings, or raw cut-off scraps used as a "body" are illegal. Kit-included wings and driver dolls must remain installed.

Body Modifications: Trimming is strictly limited to preventing interference with the chassis or parts, up to a maximum clearance of 3mm from the interfering component.

2. Permitted Modifications (The "Yes" List)

Screws & Holes:

Up to 2mm expansion of standard screw holes.

Through-hole processing of standard screw holes.

Countersinking is permitted for all screw holes.

Plates & Rollers:

Tapering the edges of FRP and Carbon plates.

Reinforcing plates with instant adhesive or bonding multiple plates together.

Roller color alterations and replacing stock bearings with Tamiya-standard bearings.

Mass Dampers:

Aesthetic coloring/painting.

Hanging configurations positioned below the plate line.

Joining multiple dampers on a single screw using Tamiya multi-tape.

Specific Tamiya Upgrade Sets Allowed:

Mass Damper Set w/ Ball Connectors (#15478 or #95180).

Multi Brake Set or Rear Skid Roller Set (#15399 or #15520).

Roller Angle Adjuster Plate Set (#15373).

Front or rear Sliding Dampers utilized without a bottom plate.

Consumables & Tuning:

Precision cutting of Tamiya brake sponges, multi-tape, or rubber piping.

Adhering/gluing tires directly to the wheels.

3. Prohibited Modifications (The "No" List)

No Part Processing: Altering the structural shape of any functional part (excluding body clearance trimming) is strictly illegal.

No modification of metal components (screws, shafts, rollers).

No altering of gears or securing gears to shafts via adhesive.

No tire carving or modification. A reduction in tire diameter by more than 1mm due to wear or shaving is considered illegal processing.

No Scrap Materials: The structural use of runners, polycarbonate scraps, or salvaged parts from a Mini 4WD Catcher is prohibited.

No Advanced Gimmicks: Advanced swing-type dynamic dampening systems (including Lanterns, Hikuo, Norio, and Catcher Dampers) are completely banned. Only vertical-movement mass dampers resting on fixed screws are permitted.

Safety Mandate: All protruding screws, threaded rods, and sharp shafts must be safely capped or protected by rubber tubes or ball poles.

4. Powertrain & Electronics

Motors: All genuine Tamiya motors are permitted for this event (No Motor Limit class rules apply). Disassembling or tuning motors for internal part swapping is strictly prohibited.

Batteries & Power: Batteries must be installed in the orientation specified by the chassis design. Battery holders must be used exactly as instructed by the manufacturer. Soldering battery contacts or double-layering batteries is illegal. ONLY Alkaline, NI-MH,NICD batteries are allowed

Drive Layout: All machines must operate in an active four-wheel drive (4WD) setup. Modifications that convert the drivetrain to front-wheel or rear-wheel drive only are strictly prohibited. All four wheels must be engaged by the motor as specified in the instructions. no two-wheel drive cars.

5. Eligible Machine Classes & Technical Inspection

Usable Machine Types: Only the following official categories are permitted:

Laser Mini 4WD, Mini 4WD REV, Mini 4WD PRO, Racing Mini 4WD, Super Mini 4WD, Fully-Cowled Mini 4WD, Aero Mini 4WD, Mighty Mini 4WD, R/C Mini 4WD, and Truckin' Mini 4WD.

Assembly Policy: As a general rule, machines must be built and assembled by the racer entering them. (Speak to a Race Official for limited, case-by-case exceptions).

Mandatory Scrutineering: All vehicles must successfully pass the official car inspection prior to racing. Cars failing to meet all technical criteria will be barred from competition until compliant.

6. Dimensional Limits & Victory Conditions

Dimension MetricRegulation Limit

Maximum Car Width

Under 105mm

Overall Car Height

Under 70mm

Overall Car Length

Under 165mm

Minimum Ground Clearance

At least 1mm

Minimum Car Weight (with battery/motor)

At least 90g

Roller Count Limit

Uncapped (No limit)

Victory Condition: To secure a legal win, the machine must cross the finish line fully upright on all four wheels, with all parts fully intact. If any component falls off the vehicle during the heat, it is a DNF (Did Not Finish).

Frequently Asked Questions (FAQ)

Q: Can I use the Ball Connector Mass Damper (15478 / 95180)?

A: Yes. These specific upgrade sets are explicitly permitted under our B-MAX 4.0 regulations.

Q: What happens if my body shell flies off during a race?

A: If the body becomes detached at any point during a competitive heat, the run is scored as an immediate disqualification. Double-check your Tamiya body catches before placing your car on the track.

Q: Are "Clone" or aftermarket replica parts allowed?

A: Absolutely not. To maintain competitive integrity, only genuine Tamiya Mini 4WD, R/C 4WD, and Dangun parts are legal.

Q: Will you use my email address to spam me with newsletters?

A: No. In accordance with our Sydney event privacy policy, your email registration details are strictly used for race-day logistics, scheduling updates, and tournament communication. Also as registration invitation to https://mini4wdshowdown.com

Source:

https://basic-max.com/2025/12/17/bmaxgp-regu-v4s/

https://www.tamiya.com/english/mini4wd/regulation_stockclass.html