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1.0 Chassis Types A/B/C/D/S

1.1 Chassis rules are a guideline. WTC officials may refuse any chassis at their discretion. WTC inspection is for competition and safety recommendations. Racing is known to be dangerous and no chassis is considered to be safe. Individual race vehicle owners, drivers and crew chiefs are responsible for the safety of their race vehicle.

1.2 Chassis Options

Type A/B NETS Chassis/ Metric Chassi / Waterford Based Chassis
- - GM 1978-1987 G Body 108 inch Metric Frame with all suspension points retained to manufacturer specs. Must be able to pass inspection using Johnson Chassis inspection tools.
  - Frame may be fabricated forward of the front spring buckets.
  - A/B Replacement of the rear frame from aft side of spring pocket perch allowed. with Minimum 2x3 x 0.90
    - Replacement tubing of the rear frame must maintain a minimum of 8 inches ground clearance.
    - Section must maintain width equal or greater than distance between outside of rear spring bucket. Rear frame between rails must use same size tubing.
    - C Channel may be boxed.
      - C Channel may be replaced with 0.125 square tubing .
        
        Minimum 2 inch X 3 inch allowed .
        
        3inch X 4 inch tubing is preferred.
    - Rear Shelf Metric (A/B/S)
      - There is no penalty of removing or altering the rear shelf
      - Please note : removal of the shelf alters the rear clip strength. A tie in replacement tubing that runs from side to side in place of the shelf is recommended..
- 1.3 Chassis replacement components
  - Frame Type A / NETS Chassis/ Type B /S Metric
    - Johnson Chassis 78-89 GM-METRIC FRAME
      - 4-Link
      - OEM 225lbs
      - 3" X 4" x .125 Main Frame Rails
      - (Must be purchased through NET or authorized chassis dealer)
  - Front Clip Type A / NETS Chassis/ Type B /D
    - Johnson Chassis X-Y-G Metric Front Clip
      - GM-METRIC TUBULAR REPLACEMENT
      - O.E.M DIMENSIONS & WEIGHT
      - USES OEM OR TUBULAR COMPONENTS
      - MOTOR MOUNTED IN O.E.M. LOCATION OR 3” SETBACK TO # 1 PLUG
      - LOWER A-ARM SLOTTED FOR WHEELBASE
        SLUGS 0”-1/4”
      - (Must be purchased through NETS or authorized chassis dealer)
    - Hamm GHC 5108
    - Hamm GHC 54108
    - Howe 358-08-01 F Body Front Frame
      - Engine must be at 11 inch crank height
      - All Howe tags and logo must be in tact
      - Team must contact Howe and supply inspection diagram
    - Howe 35819 Chevelle Type Front Frame C/D Chassis
      - All Howe tags and logo must be in tact
      - Team must contact Howe and supply inspection diagram
    - Howe 35809 Impala Type Sub Frame C/D Chassis
      - All Howe tags and logo must be in tact
      - Team must contact Howe and supply inspection diagram
    - Any snout may be submitted for approval.
- Rear Clip Type ANETS Chassis/ Type B/D
  - Johnson Rear Replacement Frame allowed
    - (PREFORMED 2”X 3”X .125
      - CLEARANCED FOR BRAKE CALIPERS 15” TALL SPRING BUCKETS )
        4-LINK W/BUCKETS
      - W/KICKERS AND TRAILING ARM MOUNTS
      - Verified Johnson Rear Frame mounts unaltered will be considered stock\
      - Rear shelf
        
        note: removal of the shelf alters the rear clip strength. A tie in replacement tubing that runs from side to side in place of the shelf is recommended..
  1.4 Roll Cage / Chassis/ Frame
  - Main Cage Tubing (Halo, Front and Rear Main Hoop, Ear bar, Door Bar)
    - 1 and 1/2 with minimum .120 wall tubing
    - 1/3/4 with minimum .090 tubing
  - Halo must be within 4 inches of front edge of roof
  - Front Hoop to Ball joint measurement maximum 28 inches
  - Rear Hoop to center of rear axle minimum 32 inches
  - Distance from top of frame to bottom edge of rear hoop minimum 40 inches.
  - Ear bar must be no more than 6 inches forward of rear main hoop (b Post)
  - All welds must be complete
  - X method for Right/Passenger side door bars is allowed
  - Drivers Door Requirements
    - Minimum 4
    - Must be plated with minimum .125 thickness steel
    - Minimum height of door bars from frame to top of bars, 22 inches
    - Padded with proper resilient padding
  - Trucks built after Feb 1 of 2016 must have
    - Continuous diagonal bar extending from drivers side top corner of rear main hoop to the base of the rear rear main hoop on the passengers side.
    - Anti bow bars must be installed to support the diagonal brace.
  - Front down tube minimum wall thickness is .083
    - Must extend forward past front spring buckets
    - Recommended to align with top driver's door bar
    - No excessive bracing
  - Aft of main hoop
    - Minimum 4 back stays
    - Minimum wall thickness .083
    - Recommend 2 back stays align with top drivers door bar and extend to area of rear spring bucket
    - Recommend to back stays run from top of main hoop to frame.
    - Fuel cell protection bar mandatory
  - Bumpers
    - Single tube - front conforming to nose
    - Single tube - rear conforming to bumper cover
    - Must contour to body
- Seekonk-Metric
  - A- Centerline hole, Forward placement of snout will use two holes for measurements. OEM - 26.5".
    Johnson/Hamm - 27.125". +/- ½". Snout MUST be centered to FRAME and REAR CLIP, NO tolerance.
    B- Frame rail lengths, from snout centerline hole to end of rail - 75" Maximum.
    C- Chassis frame rails width outside to outside Max 54.0" +/- ½".
    D- Rear clip outside to outside 42.0". Mounted centered to front snout.
    E- Wheelbase length 102.0" minimum. No tolerance.
    F- Rear clip length 66.0". +/- ½".
    G- Roll cage length, measured outside of main posts - 44.5". +/- ½".
    H- Roll cage height: top of cage to bottom of chassis - 47.0". +/- ½". The cage must stand at 90 degrees
    to the chassis and not go further back than frame rails allow at 74.5". Refer to (B)
    I- Roll cage halo 44.0" length / 29.5" width. +/- 1.0".
    J- Down bars from main cage - top 38.0" outside to outside +/- 1.0". Bottom attaches to end of chassispiece (N). Bars may intersect with other bars before connection to chassis.
    K- Roll cage A-post leg and foot bar maybe moved 3.0" to outside of main frame rail. 2” x 4” tubing .120"
    wall, must be used under the repositioned bars welded off main frame rail or in front of kickout. This is
    the only portion of the cage allowed to be repositioned, giving more leg room to the driver.
    Rear clip consists of 5-pieces L thru P using 2" x 3" .083" steel box tubing. All angles are with 36-degree
    cuts. Listed are the lengths of each piece before angle cuts are made. Don’t forget to factor in blade widths
    of saw when measuring.
    L- 18"
    M- 18"
    N- 19"
    O- 10"
    P- 25"
    Q- Length between L to O rear clip 41"
Type C
- FRAME: 1965-2015 American production full frame cars -wheelbase between 108 and 112 inches.
  - Alteration to obtain 112" wheelbase allowed
    ( must be within 12 inches of the rear mount points of the rear trailing arms.)
  - Frames may be interchanged from one manufacturer's line or make to another
- Front and rear snouts must remain stock for make of frame.
  - Cross member cannot be moved from original location , altered or out of tolerance
  - will be measured and verified by officials for year, make and model.
- No sub-frames / No Offset Frames
- Rear frame section must be stock configuration with reinforcement permitted after rear of mount points of rear trailing arms.
- Altered rear kick-up permitted for axle clearance.
- Frame rails
  - Must remain hollow. No added bracing, tubing permitted inside the frame rail.
  - No holes may be cut in the frame rails to lighten frame.
  - will be measured and verified by officials for year, make and model.
  - Two inch by four-inch steel tubing is permitted from the center of the rear axle to the rear bumper.
  - Two inch by four-inch steel tubing may be used in front of the steering box and A-frame mounts.
- 1.4 Roll Cage / Chassis/ Frame
  - Main Cage Tubing (Halo, Front and Rear Main Hoop, Ear bar, Door Bar)
    - 1 and 1/2 with minimum .120 wall tubing
    - 1/3/4 with minimum .090 tubing
  - Halo must be within 4 inches of front edge of roof
  - Front Hoop to Ball joint measurement maximum 28 inches
  - Rear Hoop to center of rear axle minimum 32 inches
  - Distance from top of frame to bottom edge of rear hoop minimum 40 inches.
  - Ear bar must be no more than 6 inches forward of rear main hoop (b Post)
  - All welds must be complete
  - X method for Right/Passenger side door bars is allowed
  - Drivers Door Requirements
    - Minimum 4
    - Must be plated with minimum .125 thickness steel
    - Minimum height of door bars from frame to top of bars, 22 inches
    - Padded with proper resilient padding
  - Trucks built after Feb 1 of 2016 must have
    - Continuous diagonal bar extending from drivers side top corner of rear main hoop to the base of the rear rear main hoop on the passengers side.
    - Anti bow bars must be installed to support the diagonal brace.
  - Front down tube minimum wall thickness is .083
    - Must extend forward past front spring buckets
    - Recommended to align with top driver's door bar
    - No excessive bracing
  - Aft of main hoop
    - Minimum 4 back stays
    - Minimum wall thickness .083
    - Recommend 2 back stays align with top drivers door bar and extend to area of rear spring bucket
    - Recommend to back stays run from top of main hoop to frame.
    - Fuel cell protection bar mandatory
  - Bumpers
    - Single tube - front conforming to nose
    - Single tube - rear conforming to bumper cover
    - Must contour to body
Type D (Street Stock Conversion)
- - Any American made production chassis with a minimum stock wheelbase of 101- 110" inches, from 1972 to current date.
    - Chassis may not be altered from stock appearance unless noted in the rules.
    - No alteration/moving of chassis suspension mounting points or spring locations
    - Cross-member may be only altered for engine clearance.
    - Reconstruction of chassis permitted from steering box forward .
    - Reconstruction of chassis permitted from center of rear wheels back.
      - Replacement tubing of the rear frame must maintain a minimum of 8 inches ground clearance.
      - Construction must resemble stock placement.
      - Minimum 2" X 3" steel box tubing .090 thickness may be used.
      - No bars may travel under rear end housing.
      - Section must maintain width equal or greater than distance between outsides of rear spring buckets. Rear frame between rails must use same size tubing.
    - Wheel base must be altered to 108 inches with 1” tolerance.
    - The use of X-Y-G Mandrel bend Johnson chassis with no modifications is permitted.
    - The use of DCA racefab as manufactured
    - Front mandrel bend clip assemblies from Johnson & DCA may be used on stock metric chassis.
    - Uni-body chassis must use sub-frame connectors.
  - C Channel may be boxed.
    - C Channel may be replaced with 0.125 square tubing .
      - Minimum 2 inch X 3 inch allowed .
      - 3inch X 4 inch tubing is preferred.
  - Chassis is eligibility is based on existing street stock being converted. Cage must be constructed by guidelines of original rules for the street stock being converted and also conform with the rules below. WTC officials may refuse any chassis at their discretion.
    - Main Cage Tubing (Halo, Front and Rear Main Hoop, Ear bar, Door Bar)
      - 1and 3/4 with minimum .090 wall tubing
      - 1 and 1/2 with minimum .120 wall tubing
    - Ear bar must be no more than 6 inches forward of rear main hoop (b Post)
    - All welds must be complete
    - X method for Right/Passenger side door bars is allowed
    - Drivers Door Requirements
      - Minimum 4
      - Must be plated with minimum .125 thickness steel
      - Minimum height of door bars from frame to top of bars, 22 inches
      - Padded with proper resilient padding
    - Front down tube minimum wall thickness is .083
      - Must extend forward past front spring buckets
      - Recommended to align with top driver's door bar
      - No excessive bracing
    - Aft of main hoop
      - Minimum 4 back stays
      - Minimum wall thickness .083
      - Recommend 2 back stays align with top drivers door bar and extend to area of rear spring bucket
      - Recommend to back stays run from top of main hoop to frame.
      - Fuel cell protection bar mandatory
    - Bumpers
      - Single tube - front conforming to nose
      - Single tube - rear conforming to bumper cover
      - Must contour to body

Type C

FRAME: 1965-2015 American production full frame cars -wheelbase between 108 and 112 inches.

Alteration to obtain 112" wheelbase allowed
( must be within 12 inches of the rear mount points of the rear trailing arms.)

Frames may be interchanged from one manufacturer's line or make to another

Front and rear snouts must remain stock for make of frame.

Cross member cannot be moved from original location , altered or out of tolerance

will be measured and verified by officials for year, make and model.

No sub-frames / No Offset Frames

Rear frame section must be stock configuration with reinforcement permitted after rear of mount points of rear trailing arms.

Altered rear kick-up permitted for axle clearance.

Frame rails

Must remain hollow. No added bracing, tubing permitted inside the frame rail.

No holes may be cut in the frame rails to lighten frame.

will be measured and verified by officials for year, make and model.

Two inch by four-inch steel tubing is permitted from the center of the rear axle to the rear bumper.

Two inch by four-inch steel tubing may be used in front of the steering box and A-frame mounts.

Main Cage ( Halo, Front and Rear Hoop, Ear bar and Door bars)

1and 3/4 inch with minimum 0.90 wall tubing

Distance between main hoops must be 53 inches

Brain bar must be added

Center windshield bar mandatory

Door bars

4 driver's door bars

3 Right Side door bars

Bumpers

Single tube - front conforming to nose

Single tube - rear conforming to bumper cover

Must contour to body

Type Seekonk-Sport (Except new Seekonk Metric)

Main Cage Tubing (Halo, Front and Rear Main Hoop, Ear bar, Door Bar)

1and 3/4 with minimum .090 wall tubing

1 and 1/2 with minimum .120 wall tubing

Ear bar must be no more than 6 inches forward of rear main hoop (b Post)

All welds must be complete

X method for Right/Passenger side door bars is allowed

Drivers Door Requirements

Minimum 4

Must be plated with minimum .125 thickness steel

Minimum height of door bars from frame to top of bars, 22 inches

Padded with proper resilient padding

Front down tube minimum wall thickness is .083

Must extend forward past front spring buckets

Recommended to align with top driver's door bar

No excessive bracing

Aft of main hoop

Minimum 4 back stays

Minimum wall thirstiness .083

Recommend 2 back stays align with top drivers door bar and extend to area of rear spring bucket

Recommend to back stays run from top of main hoop to frame.

Fuel cell protection bar mandatory

Bumpers

Single tube - front conforming to nose

Single tube - rear conforming to bumper cover

Must contour to body

Chassis Weight -All trucks must be specified minimum weights and percentage at all times
.

Automatic`/ Standard Transmission 2900 lbs

Weight Tolerances: None

Maximum left side weight percentage 56%

Wheel base 102
inches

Add 10 lbs for every inch / 5 lbs per 1/4 inch under 108

Ground Clearance

All components / body parts must maintain a minimum of 4 inches ground clearance.

Chassis 4 inches

Fuel Cell 7 inches

Exhaust 4 inches

Crankshaft height / placement

12 inches

Centered between frame rails

Engine location

Forward most spark plug must be even or forward of an imaginary line between ball joints.