4" Nascar Rules



Motor: Cans: Stock Parma 498, 499, 501, 502 or Pro Slot 16D.

Bushings only and may be soldered in. 

No bearings allowed!

Armature: Must be Tagged NvS Pro Slot 16D arm. Armature may be any timing, Commentator may be trued. Arm Die is allowed. NO other modifications allowed. .600" stack, 70T/30 gauge wire. 

Any arm that appears modified will be rejected.

Magnets: Must use stock magnets (EPX magnets included).

Endbell - (Stock Parma Black, Green endbell or Pro Slot)

Any brush & spring  Any brush hood or post hardware.

Chassis: Any approved 4 inch flexi stamp steel chassis.

Starting Jan 1 2018 aluminum pans are allowed

1/8 or 3/32 solid steel rear axle

Any pitch straight or angle pinion & any pitch plastic spur gear

May run any height guide flag, shims, nut and approved braids.

.047 tech tool must clear gear, and rear of chassis.

Axle bushing holes may be altered in chassis to lower or raise bushings. Bushing may be soldered in.

No bearings allowed.

No excessive chassis contact to the race track.


Any rear tires, no minimum size, as long as minimum chassis height is maintained.

Tires may be changed but must pass tech tool height .047 & width 83mm (3.268”) when changed, even during the race and approved by Race Director

Rear tire width must pass tech tool 83mm (3.268”) at all times before, during & after race.


Any 4" Nascar body approved by Randy McAnulty or appointed race director

Must be painted.

All bodies must have 1/16 front & rear bumper

Body proofing or tape may be used for inner strength, no outer aerodynamic improvements allowed

No heating, pinching or reforming bodies for aerodynamic purposes

No cutting out window or open holes in car body

Body must be mounted as intended by manufacturer to look like real race cars

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