SPEC JET CLASS RULES

These are 2022 HOPRA rules. They apply to our former Viper V-SPEC "Viper-Jet" class of car. Differences between HOPRA rules are indicated in red.

Legal chassis’ are: BSRT G3/G3R/G3RS/G3RSB, Slottech T1/T2/T3, Wizzard Storm/Fusion, Viper V-SPEC (V1) Viper-Jet

    1. The chassis must be stock, readily available, “HOPRA Approved” and cannot be machined, sanded or cut except to provide for the following:
        1. Add, remove or re-add body mounts.
        2. Reinforce and/or replace pickup tabs.
        3. Add axle retainer.
    2. All front and rear weights and hardware must be used and must be from the same manufacturer as
      the chassis. Harden Creek is not listed as a manufacturer per HOPRA Legal Chassis rules above.
    3. Weight kits must contain 1 or 2 front weights and 2 rear traction weights made of brass only. Total
      weight kit, including mounting hardware, must weigh a minimum of 1.8 grams.
    4. All magnets shall remain in their stock location. No material or method may be used to restrict the movement of the magnets.
    5. Only “HOPRA Approved” Compression-Molded Ceramic Grade polymer motor magnets may be used.
      High Downforce (HD) magnets are not allowed, see “SPEC” STOCK CAR CLASS RULES for specific
      manufacturer part numbers.
    6. The gauss reading of the motor magnet shall not exceed the following criteria. This is taken after 5 min
      cool-down period and at the lowest point on each magnet as it runs parallel to the rail. Any reading
      above these figures will be cause for disqualification or rejection at tech:
      MOTOR: 1250 gauss maximum.
    7. The guide pin can be a stock replacement. It may be glued in place but shall remain in any one of the stock positions.
    8. The armature must be stock or hot stock. The minimum ohmage allowed shall be 5.8.
    9. There are no restrictions on the armature bushings or axles. Ball bearings are not allowed.
    10. The gear ratio must be a 7-tooth pinion with a 23-tooth crown gear. No metal gears allowed.
    11. There are no restrictions on front wheels, tires and or axle.
    12. Rear tires shall be readily available solid silicone, rubber, or urethane replacement tires. Rear wheels shall be readily available double or single flanged replacement wheels.
    13. Electrical systems shall be stock or stock replacement. Adjustable brush tension is allowed. Physically attaching brushes to springs (using glue or other substance) or spring arm is allowed. Plated parts are allowed. Shunts are not allowed.
    14. The use of glue shall not be allowed on the chassis, magnets, or bulkheads. Body mounts, guide pin and armature bushings may be glued into place.
    15. Formula V and Formula G (Jet) versions of this class must run in the long-wheelbase front axle positions and utilize a hard plastic or resin F1/Indy style open-wheel body.
    16. Any non-independent front-end, including Viper “Razor” or any non-weighted o-ring-style front-end, may be used. However, doing so will disqualify you from any Concourse d’Elegance or Best Appearance Race Car competitions in this class.
    17. Track voltage for this class will be 12.5 volts.