Shocks, dampers, and springs

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Shocks, dampers, and springs

• Joe Filomeno
• George Lapaan
• AJ Spagnoletti
• Matt Tucker

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Suspension Rules

• 1. The car must be equipped with a fully
  operational suspension system with shock
  absorbers, front and rear, with usable wheel
  travel of at least 50.8 mm (2 inches), 25.4 mm (1
  inch) jounce and 25.4 mm (1 inch) rebound, with
  driver seated. The judges reserve the right to
  disqualify cars which do not represent a serious
  attempt at an operational suspension system or
  which demonstrate handling inappropriate for an
  autocross circuit.
• 2. All suspension mounting points must be visible
  at Technical Inspection, either by direct view or
  by removing any covers.

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Compressed Gas Rules

• Working gas must be nonflammable (nitrogen)
• The gas cylinder/tank must be of proprietary
  manufacture, designed and built for the pressure
  being used, certified by an accredited testing
  laboratory in the country of its origin, and
  labeled or stamped appropriately.
• The pressure regulator must be mounted directly
  onto the gas cylinder/tank.
• The gas cylinder/tank and lines must be protected
  from rollover, collision from any direction, or
  damage resulting from the failure of rotating
  equipment and cannot be in the cockpit.
• The gas cylinder/tank must be securely mounted to
  the Frame, engine or transmission.
• The axis of the gas cylinder/tank must not point
  at the driver

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Theory

• Modeled the car with a quarter car model
• Equations of Motion

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Components

• Frame
• A-Arms
• Rocker
• Push Rod
• Shock
• Spring
• Sway Bar

Video
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Option 1

• Ohlins DB-1 Damper
• 200mm free length
• 57mm stroke
• 4way adjustable with independent high and low
  speed adjustments for compression and rebound.
• Small diameter, twin tube design
• Nitrogen gas charge in external reservoir
• Adjustable spring preload
• Ohlins Spring Kit
• Includes 16 springs
• 4 x 150lb/in
• 4 x 175lb/in
• 4 x 200lb/in
• 4 x 225lb/in
• Other spring rates available but sold separately

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Option 2

• FOX DHX RC4
• - .99 lbs (without reducers or spring)
• -Externally adjustable velocity sensitive
  damping(DSC)-High speed compression-Low speed
  compression-Bottom-out progressiveness-Rebound-
  Coil Spring preload
• -7.875 in eye to eye, 2.25 inch stroke
• FOX 300 lb to 600 lb springs (50 lb increments)
• Other spring rates available but require
  different sized shocks

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Push Rod and Rockers

• Push rod and rockers will be required
• Will require frame geometry
• Will work with frame on this

Yanelle
Rocker
Push Bar
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Sway Bar

• Will design sway bar
• Implementation of sway bar pending on handling of
  car without one
• Once rockers are designed, sway bar will be
  designed

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Cost

• Ohlins

Fox dhx rc4

• 610 per damper
• 175 for spring kit
• 30 per additional spring
• Total (6104)175 2615
• Running Cost (6104) (175/16)4 2483.75

• 585 per spring and damper
• Total 5854 2340
• Running Cost 2340

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Questions?