MX-5 (CSX) Rules


Provide an affordable multipurpose package that combines a street-ready, autocross capable and track appropriate performance in a single car using specified parts.

Eligible Vehicles

2006-2015 Mazda MX-5 (NC Chassis)

Vehicle Requirements

6-Speed Manual Transmission or Automatic Transmission
Minimum Vehicle Weight, as weighed without Driver (lbs): 2500

Required Performance Kit

  1. Parts specified below (tires, wheels, and suspension) must be used. All components and parts (e.g., hardware) are required to be installed per manufacturer instructions. Original equipment (OE) or equivalent components are not allowed.
  2. Tires: Falken Azenis RT660, size: 225/45R17
    • Note: For Time Trials events in wet conditions, any tire with a treadwear rating of 300 or higher and a section width of no more than 225 may be utilized.
  3. Wheels
    1. Diameter and width (in.): 17x8
    2. Offset, including wheel spacer (mm): +45 (45ET or ET45) or greater
    3. Weight, without spacer if used, minimum (lbs.): 15, including:
      1. Wheel weights
      2. TPMS sensor if installed
      3. Tire valve stem (type unrestricted)
    4. Wheel spacers are allowed provided the resultant combination with the wheel complies with the offset requirements.
  4.  Suspension
    1. Penske Front Shock (2), Part# 0000-04-5291-SA
    2. Mazda Motorsport Front Mount Kit, Part# 0000-04-5359
    3. Mazda Motorsport Front Offset Bushing Kit, Part# 0000-04-5407-NC
    4. Eibach Front Spring (2), Part# 0000-04-9700-08
    5. Penske Rear Shock (2), Part# 0000-04-5292-SA
    6. Mazda Motorsport Rear Mount Kit, 0000-04-5358
    7. Mazda Motorsport Rear Shock Alignment Spacer, Part# 0000-04-5294
    8. Eibach Rear Spring (2), Part# 0000-04-9400-07
    9. Eibach Helper Springs (4), Part# 0000-04-9926
    10. Eibach Front and Rear Sway Bar Kit, Part# 0000-04-5306-EB
    11. Mazda Motorsport Sway Bar End Links (4), Part# 0000-04-5597-KT
    12. Penske Adjustment Knob (Recommended), Part# 0000-04-5293

Authorized Changes/Modifications

  1. If a change or modification is not specifically authorized, it is not allowed. All repairs must comply with factory-authorized methods and procedures, or industry standard methods, as follows: If the manufacturer does not provide an appropriate method of repair, industry standard methods and procedures may be used. Such repairs may not result in a part or combination of parts that provides a performance advantage (e.g., significant change to weight, suspension control, power, etc.) as compared to the standard part(s). Competitors are strongly cautioned to use this allowance to make common-sense repairs only.
  2. Wheel lug studs (e.g., length) and lug nuts may be changed.
  3. Components which are normally expendable and considered replacement parts may be used provided they are essentially identical to the standard parts, used in the same location, and provide no performance benefit. Examples are:
    1. Clutch and related components (excluding flywheel).
    2. Hardware (nuts, bolts, clips, etc.).
  4. Parts superseded by Mazda® may be used.
  5. These allowances are strictly to permit components to be replaced from alternate sources other than the original manufacturer. They should not be construed as an allowance to replace components with those which could be considered a “higher performance” alternative.
  6. It is not permitted to use non-compliant parts even if they have been set to the manufacturer’s specifications.


  1. Front bumpers, rear bumpers, body trim pieces, and attachment points may be reinforced to prevent or repair damage from hitting cones. Reinforcements that are not visible to the exterior of the car are allowed. Such repairs and/or reinforcements may serve no other purpose.
  2. Accessories, gauges, indicators, lights, and other appearance, comfort-and-convenience modifications which have no effect on performance and/or handling and do not materially reduce the weight of the car are permitted. This does not allow driver’s seat substitutions, or the removal of “tow hooks” or “tie-down loops.” Data acquisition systems (including video cameras) and the accompanying sensors are allowed but may serve no other purpose during a run than real-time display and data recording.
  3. Alternate shift knobs are allowed.
  4. Spare tires, tools, and jacks may be removed. Any fastening hardware and/or other pieces that can no longer be firmly secured in the absence of the spare tire may be removed if necessary to ensure compliance with Solo® Rules section 3.3.3.B.1, Safety Inspections, Inspection Requirements.
  5. Cars may add one (1) rear trailer hitch. Factory tie downs and cosmetic pieces (e.g., diffusers) may be modified or removed to facilitate hitch installation. Complete or partial removal of the hitch is allowed for competition, provided it does not result in a reduction in weight compared to the unmodified standard configuration.
  6. Tow bar brackets may be installed and may serve no other purpose.
  7. Any item not permanently in place by manufacturer-installed fasteners may be removed (i.e., emergency tool kits).


  1. SCCA Safety Levels 2 and 3 are allowed.
  2. Provided the vehicle fully meets SCCA Safety Level 2 as defined in the Time Trials Rules, the following may be added, replaced, or modified within the guidelines stated in Safety Level 2:
    1. Compliant Rollbar (Required for Safety Level 2)
    2. Fixed back racing seats for driver and passenger side
    3. Racing harness(es)
    4. Replacement of steering wheel and/or removal of steering wheel airbag
  3. Interior modifications and/or soft top removal, as required per manufacture's installation instructions, are allowed to facilitate the installation of safety equipment. Interior modifications should be kept to the minimum required for installation; factory restraints must be retained.
  4. Vehicles that do not meet SCCA Level 2 Safety may not substitute or modify seats or steering wheel, however a lap belt, as outlined in Solo® Rules section 3.3.1, Driver Restraints, is allowed. Seats may not be cut to allow for the installation of alternate seat belts or harnesses.
  5. If the vehicle is equipped with a minimum 6-point roll cage, driver's seat, and restraints meeting SCCA Time Trials Safety Level 3 standards, all interior carpet, trim, and passenger seats other than the factory dash may be removed.
  6. Level 2 Fire Suppression is not required for Solo Events


  1. The make and material of brake linings (pads) may be changed.
  2. Goodridge G-Stop Brake Line Kit is allowed, Part# 0000-03-5212
  3. Mazda Motorsports 2.5” Brake Duct Kit is allowed, Part# 0000-03-5301-NC


  1. Alignment: Both the front and rear suspension may be adjusted through their designed range of adjustment by use of the specified parts. No suspension part may be modified for the purpose of adjustment unless such modification is specifically authorized by the manufacturer service documentation.
  2. Bushings
    1. Suspension bushings as supplied in the kits are mandatory.
    2. Those not included in the supplied kits may not be replaced with bushings of a different material or dimension.
  3. The Mazda Motorsports Competition Rear Hub, Part# 0000-04-5530, and Rear Hub Bearing, Part# 0000-04-5531 may be utilized.
  4. Mazda RX-8 Front Hub may be utilized, Part# F189-33-04X

Electrical System

  1. The make of spark plugs is unrestricted.
  2. Tire Pressure Monitoring Systems (TPMS) may be disabled. Altering the signal to the TPMS module is allowed.

Engine and Drivetrain

  1. The air intake system, upstream of the throttle body, may be replaced with the Mazda Motorsport Intake System, Part# 0000-06-5150-KT
  2. The engine management system parameters may be modified only via the methods listed below.
    1. OE ECU software may be reprogrammed, but no changes to the factory ECU hardware are permitted.
    2. Any OE OBD2 or newer communications port functionality must remain.
  3. Oil filters are unrestricted.
  4. Lubricants and fluids are unrestricted.
  5. The installation of oil catch tanks or oil separators is allowed provided the function of the PCV system remains functional.
  6. Engine oil coolers and lines may be added or substituted (including oil to coolant heat exchangers) provided they serve no other purpose. It is highly recommended to use the Mazda Motorsports oil cooler adapter and lines (0000-01-5511-KT), as a traditional sandwich plate adapter installed to the factory oil filter housing is known to cause the housing to fail.
  7. Engine cooling radiators may be replaced with alternate parts subject to the following restrictions:
    1. Radiator core dimensions (width, height, thickness) cannot be smaller than the standard part
    2. Radiator must use OE radiator mounts
  8. The radiator overflow tank may be substituted provided the replacement tank has the same capacity, function, and mounting location as the original tank.
  9. Alternate exhaust and muffler may be utilized provided it mounts to the manifold flange labeled “Z” below, the muffler is in the stock location and is at least 6 inches in diameter or 4x6 inches if oval.
  10. Fuel must be Federally approved for use on public highways and widely distributed and typically sold in filling stations, commonly called “pump fuel” with typical octane ratings or AKI (Anti-Knock Index) (R+M/2) displayed on the pump between 87 and 93. The maximum octane rating allowed is what is typically delivered from a pump marked 93 octane*. Fuels comprised of more than 15% ethanol may only be used when specified by the manufacturer (e.g., in the owner’s manual for flex-fuel vehicles).

*Octane verification: Octane levels will vary from the number listed on the pump. Octane testing has a “margin of error” and different testing procedures will produce similar but different results. For the purposes of testing gasoline, a result that exceeds 95.9 octane is not allowed and will result in a disqualification with no exceptions (hard limit). This limit gives competitors a 99.99+% confidence level that fuel purchased from a pump marked 93 octane is compliant. Warning: Competitors attempting to approach the 95.9 octane limit through mixing or by any other means may inadvertently create fuel that appears compliant but may test above the 95.9 hard limit.