Rules

5th Scale Dirt Late Model

11/16/2021 Rev. B

VOT Approved

Bodies:

  1. Maximum overall length 45".

  2. Maximum width where deck and A post meet and where rear quarter panel and deck meet 20".

  3. Maximum width at front flopper's widest point 26".

  4. Maximum Deck to Roof height is 4 ½ inches.

  5. Must have the Woo/Lucas appearance (No wedge style bodies).

  6. Only holes allowed in deck are for Spark plug and Transponder.

  7. There will be no metal body parts of any kind. Roll cage and body supports can be metal.

  8. No part of the deck can be higher than 12" from ground.

Rear Spoiler Specs:

  1. Rear spoiler can only be as wide as the body at the rear quarter panels.

  2. Rear spoiler 5" max from deck.

  3. The end caps must be a triangle shape and be in proportion to today’s Late Models.

  4. You may have one fin on the spoiler and two side caps.

  5. The 3rd fin must also be the same dimension as side cap.

  6. The 3rd fin can be located anywhere on the spoiler between the two side caps.

  7. The 3rd fin must be in line with the side caps on the front leading edge.

Chassis & Suspension:

  1. Must be 1/5 production based stamped 2 WD 5B buggy chassis.

  2. No shortened, extended, offset or flat style chassis allowed. All chassis and motor plate dimensions, shape, and configuration must remain stock.

  3. All parts must be stock or aftermarket stock style Baja upgrades. (Durability only).

  4. 16 MM bore stock type shock only.

  5. Tethers, limiters and compensators are allowed.

  6. All A arms must be stock dimensions. (No extended A arms).

  7. Rear toe must be adjusted the rear hubs.

  8. Wheel extenders allowed. (2” maximum per wheel).

  9. Adjustable front and rear shock towers allowed.

  10. All components must remain in stock locations. (including the battery).

  11. No shimming or spacers under mounting points to chassis.

  12. Rear hinge pin holder can be adjustable. From zero up to three degrees. No others can be moved.

  13. No ballast/weight allowed anywhere on chassis or body.

  14. No metal or carbon fiber front bumpers.

  15. All parts must be available to the public from a Store front/Track hobby shop or on-line STORE.

  16.  No homemade chassis or suspension parts of any kind.

  17. No two speeds.

 

Engine:

OPEN ENGINE:

  1. Size: 23cc to 30.5cc max.

  2. Piston port only. (No reed valve).

  3. Stock style/size flywheel.

  4. Stock style head only.

  5. Exhaust Can Style Only. (DDM# CY-15483). May weld the stinger. You may port match the muffler to the exhaust port of the head. NO OTHER MODIFICATIONS ALLOWED.

STOCK ENGINE:

  1. Zenoah G290RC (DDM #bb211) Engine Only as supplied from Zenoah.

  2. Stock Zenoah replacement parts only unless specified in these rules.

  3. No porting, grinding or modification to the Intake, Cylinder Head, Ports or Crank Case.

  4. May replace 3rd bearing with a seal.

  5. Bearings must be stock replacement bearings only. (No Ceramic Bearings Allowed).

  6. Walbro WT-990 Carbonator Only. (No Modifications).

  7. May set pop off.(Change or cut Spring).

  8. May run ball bearings on throttle shaft. (Stock throttle shaft ONLY).

  9. Cylinder head base gasket must be DDM# CA336 or CA337 ONLY.

  10. May run the stock intake and gaskets or the DDM# AV540 intake any color with supplied gaskets or DNRE Blue Gaskets. No Modifications.

  11. Any commercially available Air Filter, Filter Adaptor or Velocity Stack.

  12. Muffler CY-15483 Only. May weld muffler stinger. (No modifications).

  13. 1 exhaust gasket only. (May use the stock gasket or copper Gasket).

  14. Zenoah or CY Stock Clutch Assembly Only. (No Modifications).

  15. May run any clutch spring.

  16. No high response clutches

 

Engine Non-Tech Items:

  1. Clutch Housing.

  2. Fan Cover.

  3. Engine Cover.

  4. Starting System.

  5. May repair stripped holes with HELI-COILS. (Location and Size must remain the same as stock).Zenoah G290RC engine is a 28.5cc (36mm bore, 28mm stroke)Zenoah G290RC engine is a 28.5cc (36mm bore, 28mm stroke)Zenoah G290RC engine is a 28.5cc (36mm bore, 28mm stroke)

Wheel & Tire Specs:

  1. Rubber tires only!

  2. All wheels must be bead lock buggy based.

  3. Must be 1/5 scale.

  4. Cutting, siping and grooving are allowed.

  5. Traction compounds are allowed.

 

Fuel:

  1. Gas Only.

Electronics:

  1. Stability/Gyro control for steering only

  2. Full AVC may be track option.

General Rules:

  1. The Track and Track Officials have final say on rules enforcement.

  2. The Track and Track officials reserves the right to change any rules and specifications at any time in the fairness of the hobby!

5th Scale Dirt Modified

11/16/2021 Rev. B

VOT Approved

Bodies:

UMP Style Bodies:

  1. Maximum overall length 45 inches.

  2. Maximum deck width 19 inches. (At no point can the deck be lower than ¾ inch from the top of the doors).

  3. Maximum deck height is 12 inches from rear of deck to ground.

  4. The front deck height must be a minimum of 8 inches high from ground.

  5. Nose width can be a max of 10 inches at front/bottom leading edge. (Edges/lips on the sides of the nose can be no taller than ½ inch).

  6. The hood must tapered out to the “A” post the full width of the deck. (Meaning the rear of the hood must be the same width as the front of the deck).

  7. Door panels can be a max of 28 inches long. 

  8. Roof dimensions:

    1. 14 inches wide maximum.

    2. 12 inches long maximum.

    3. Maximum height from deck to roof is 4.5 inches. Maximum ½ inch of rake. (Meaning the front can be no more than ½ inch lower than the rear measured from the deck).

  9. Sail panel can be a maximum of 12 inches long if attached to the spoiler. A maximum of 10 inches long if side boards are used. The sail panel must taper down from the roof to the spoiler. (It cannot be squared off).

  10. Sail panel must be closed. (Window between “A” pillar and sail panel must be open and must be a minimum of 3 inches tall).

  11. Spoiler maximum height is 3 inches.

  12. Spoiler side boards max of 3 inches long, 3 inches high at rear, and 1.5 inches high at the front.

  13. Rear spoiler can be no wider than the body.

  14. No air scoops that direct air for motor or cooling.

  15. No Aero devices in/on decking.

  16. Must have todays Open Wheel UMP Modified appearance.

 

EDM and Big Block Mod Bodies:

  1. Maximum overall length 42”

  2. Maximum width of deck at any point 18”

  3. Maximum width of nose at front/bottom leading edge 10”

  4. Maximum length of side panels 30”

  5. Maximum width of side panels 9½”

  6. Maximum height of roof at any point 5 ½” from deck

  7. Roof maximum width 15” length 14”

  8. Maximum height of sail panel from deck 6”

  9. No air scoops that direct air for motor cooling. No aero devices in/on deck

  10. There will be no metal body parts of any kind. Roll cage and body supports can be metal

  11. Must have appearance of current EDM car, refer to pic.

  12. No part of deck can be higher than 12” from bottom side to ground

Rear Spoiler Specs:

  1. Rear spoiler can only be as wide as the body at the rear quarter panels

  2. Rear spoiler 3” max from deck

         

 

 

         

 

Chassis & Suspension:

  1. Must be 1/5 production based stamped 2 WD 5B buggy chassis.

  2. No shortened, extended, offset or flat style chassis allowed. All chassis and motor plate dimensions, shape, and configuration must remain stock.

  3. All parts must be stock or aftermarket stock style Baja upgrades. (Durability only).

  4. 16 MM bore stock type shock only.

  5. Tethers, limiters and compensators are allowed.

  6. All A arms must be stock dimensions. (No extended A arms).

  7. Rear toe must be adjusted at the rear hubs.

  8. Wheel extenders allowed. (2” maximum per wheel).

  9. Adjustable front and rear shock towers allowed.

  10. All components must remain in stock locations. (including the battery).

  11. No shimming or spacers under mounting points to chassis.

  12. Rear hinge pin holder can be adjustable. From zero up to three degrees. No others can be moved.

  13. No ballast/weight allowed anywhere on chassis or body.

  14. No metal or carbon fiber front bumpers.

  15. All parts must be available to the public from a Store front/Track hobby shop or on-line store.

  16.  No homemade chassis or suspension parts of any kind.

  17. No two speeds.

Engine:

OPEN ENGINE:

  1. Size: 23cc to 30.5cc max.

  2. Piston port only. (No reed valve).

  3. Stock style/size flywheel.

  4. Stock style head only.

  5. Exhaust Can Style Only. (DDM# CY-15483). You may weld the stinger. You may port match the muffler to the exhaust port of the head. NO OTHER MODIFICATIONS ALLOWED.

STOCK ENGINE:

  1. Zenoah G290RC (DDM #bb211) Engine Only as supplied from Zenoah.

  2. Stock Zenoah replacement parts only unless specified in these rules.

  3. No porting, grinding or modification to the Intake, Cylinder Head, Ports or Crank Case.

  4. May replace 3rd bearing with a seal.

  5. Bearings must be stock replacement bearings only. (No Ceramic Bearings Allowed).

  6. Walbro WT-990 Carbonator Only. (No Modifications).

  7. May set pop off.(Change or cut Spring).

  8. May run ball bearings on throttle shaft. (Stock throttle shaft ONLY).

  9. Cylinder head base gasket must be DDM# CA336 or CA337 ONLY.

  10. May run the stock intake and gaskets or the DDM# AV540 intake any color with supplied gaskets or DNRE Blue Gaskets. No Modifications.

  11. Any commercially available Air Filter, Filter Adaptor or Velocity Stack.

  12. Muffler CY-15483 Only. May weld muffler stinger. (No modifications).

  13. 1 exhaust gasket only. (May use the stock gasket or copper Gasket).

  14. Zenoah or CY Stock Clutch Assembly Only. (No Modifications).

  15. May run any clutch spring.

  16. No high response clutches

Engine Non-Tech items:

  1. Clutch Housing.

  2. Fan Cover.

  3. Engine Cover.

  4. Starting System.

  5. May repair stripped holes with HELI-COILS. (Location and Size must remain same as stock).Zenoah G290RC engine is a 28.5cc (36mm bore, 28mm stroke)Zenoah G290RC engine is a 28.5cc (36mm bore, 28mm stroke)Zenoah G290RC engine is a 28.5cc (36mm bore, 28mm stroke)

 

Fuel:

Gas only!

Wheel & Tire Specs:

  1. Mods must run buggy narrow front wheel and tire.

  2. Rubber tires only.

  3. All wheels must be bead lock buggy based.

  4. Must be 1/5 scale.

  5. Cutting, siping and grooving are legal.

  6. Traction compounds are legal.

 

Electronics:

  1. Stability/Gyro control for steering only.

  2. Full AVC may be track option.

 

General Rules:

  1. The Track and Track Officials have final say on rules enforcement.

  2. The Track and Track officials reserves the right to change any rules and specifications at any time in the fairness of the hobby!

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