4.5" NASCAR Rules





1.       Any 4.5" chassis that is a maximun of 3.25” wide & is commercially through a distributor & available at the raceway.  Must be approved prior to October 30, 2019.

2.       If using extenders must use original manufacturer’s extenders on the chassis, they were designed for.

3.       May solder extender to chassis.

4.       May remove front wings for extender / front wheel clearance only.

5.       May be laser, EDM, Water Jet, milled, die cut. stamped and formed metal only.

6.       May brace chassis in any way you would like.

7.       A steel guide tongue reinforcement may be used, but the original guide tongue may not be removed, modified, or moved.

8.       Must use rear & front axle bushings on chassis that allow front bushings to be installed.  Ball bearings are NOT allowed.

9.       Total weight must be a minimum of 100 grams.




1.       Must run a 9:37 gear ratio.

2.       Angled pinions are allowed.

3.       May solder pinion on motor.

4.       Must use 64 pitch gears.



1.       Minimum axle diameter front 3/32", rear 3/32". Drill blank axles allowed.

2.       Tires front and rear must be composed of black foam rubber only.  No dyed tires allowed.

3.       May add nail polish to fronts.

4.       Rear minimum tire diameter .810".  Front minimum tire diameter .790” with a minimum front tire width of .400”.  Maximum rear tire width .810''.

5.       Independent rotating fronts allowed.

6.       MUST RUN with the Front tires and axle on the car for the ENTIRE RACE.

7.       Solid, one-piece front axles only, no stubbies.

8.       Front axles may be soldered solid, but front wheels must rotate.

9.       Steel axles only. No hollow or other lightweight axles.

10.   Must use front & rear axle bushings.  Offset bushings are allowed.  Ball bearings are NOT allowed.

11.   Maximum width is 83mm.

12.   .050” clearance at the back, up to the rear axle.

13.   Must have .015" clearance in front of chassis, measured where chassis widens behind front axle, sitting on tires on tech block with the Guide not touching.  Gauge must slide under without lifting tires from tech block.


1.       Magnet wire or magnet type wire is not allowed.

2.       Guide clips are allowed.

3.       May add wire guide or retainer.

4.   Weighted guide flags are allowed.


1.       Body must be commercially available and on approved body list.

2.       1/8" minimum front & rear bumper and must see the front splitter on the front of the car.  On the Outisight 4.5 NASCAR Body, the rear must have a 1 1/8” rear fender height that is measured from the top of the spoiler downward.  Can’t put holes or any cuts/slits into rear. 

3.      Maximum rear spoiler height of 1 5/8", measured from the tech block to the top of the spoiler. The tech tool must go all the way across without any part of the spoiler going over the tech tool.

4.       Must have three scale appearing numbers.

5.       Body must be fully painted and cover the entire chassis.

6.       May reinforce body with tape or Lexan.

7.       All windows must be clear and retain factory Lexan.

8.       Front wheel wells must be cut out. No cutting into the top of the fenders.  Chassis or track must not be visible.

9.       Must use a fully molded 3 D driver figure interior.  Must have a two-color presentably, realistically painted.  No paper interior.  Must be stock car type interior.  Must completely cover the chassis.

10.   Bodies may not be moved forward or backward on the chassis.

11.   Tires must be located in the proper positions. Wheel wells must be cutouts. Full wheel and tire must be visible when viewed from the side.

12.   May NOT cut out the rear of the body.




1.       Must use Proslot Sealed Balanced 16D motor.  (Part #PS2002)

2.       Motors must not have been opened or tampered with in any way.

3.       Motors must be factory sealed and using the unmodified factory seal only. Seals may have clear "fingernail polish" added to extend life of seal.  NO other modifications to the seals allowed.

4.       Any motor brush may be used.

5.       Any motor spring may be used.

6.       Can NOT make any alterations to the end bell and can.

7.       Can motor bushing may be soldered.


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