General Criteria for All Cars

General Criteria for All CVAR Production Cars

  1. All cars must be prepared to the SCCA GCR/PCS limited to the year 1972. Any appropriate earlier year may be chosen but cars must be prepared to a single year. No mixing and matching of rules from different years is allowed.
  2. Cars must be prepared to specifications listed on their respective page in the PCS. Cars may not be modified beyond their singe page unless specifically authorized within the GCR or by BoD approved exceptions to the GCR.
  3. Post 1972 unibodies up to 1990 may be used in the construction of cars provided they are fully back dated to 1972 or earlier specs. It is up to the entrant to prove there are no structural enhancements in the later unibody.
  4. Tires must be fully treaded (60% of the tread width must have full depth grooves formed by the manufacturer);the tread pattern must be molded, not hand cut. Shaving is permitted as long as the minimum required tread depth is maintained across the entire width of the tread face. Competition tires are typically molded with a tread depth of 5/32” to 6/32” and should not need shaving. Street tires are typically molded with tread depths of 8/32” to 10/32”. Tire manufactures recommend shaving streettires to a depth of 4/32” to 5/32” when used for competition. In all cases, tires must have 2/32” minimum tread depth at all times during competition. Treaded tires of minimum 60 series aspect ratio must be used unless an exception is specifically granted by the BoD. Measured tread width will be used to determine aspect ratio.Other brands and styles will be reviewed and approved or denied upon application by the Authenticity Committee. Approval will be so noted on the Declaration sheet by the Tech Inspector.
  5. Heads must conform to practice of the period year and be OEM with a casting number available before orduring 1972. For guidance please see a group representative.
  6. No roller cams are allowed unless fitted from the factory.
  7. Aftermarket blocks are allowed provided they are of the same material as OEM and critical dimensions are the same.
  8. Aftermarket engine internals are allowed, providing they are the same material (Ferrous/non-ferrous) as original.
  9. Production cars may upgrade to bigger versions of their originalcarburetors or replace them with Webers with the same number of barrels, (i.e. Midget with a single Weber in place of two SU’s).
  10. Intake manifolds must be OEM, period aftermarket, or aftermarket of period design. For V-8 cars, aftermarket manifolds must be of period design, non-air gap, and dual plane.
  11. Aftermarket control arms are not allowed.
  12. Specifically excluded are aftermarket dog-ring transmissions or transmissions that have been modified to accept Hewland type gears that may be shifted without using the clutch.
  13. Aftermarket rotors may be used provided they are the same diameter as originally provided and stock caliper reused and mounted in stock location.
  14. Battery should remain in stock location. However if moved, it may be removed only to the trunk and will carry a one-point deduction.
  15. Rocker arms must remain stock ratio. Roller or ratio rockers are not allowed, unless specifically allowed by CVAR Board of Directors.
  16. Modern electronic ignitions are allowed. No crank fire ignition.
  17. Any fastback Mustang may be configured as a GT-350 or GT-500 without loss of originality points as long as external appearance is faithfully replicated as well. Also, Yenko Stinger can be made out of 1965-1969Corvair.
  18. SFI-approved after market engine damper/balancer is recommended.(no point deduction)

General Criteria for All CVAR Sedan Cars

  1. All cars must be prepared to an appropriate SCCA GCR.
  2. No mixing and matching of rules from different years is allowed.
  3. Cars may be updated within “Authorized and Required” modifications as listed in the GCR and BoD approved exceptions.
  4. Post 1972 unibodies up to 1990 may be used in the construction of cars provided they are fully back dated to 1972 or earlier specs. It is up to the entrant to prove there are no structural enhancements in the later unibody.
  5. Tires must be fully treaded (60% of the tread width must have full depth grooves formed by the manufacturer); the tread pattern must be molded, not hand cut. Shaving is permitted as long as the minimum required tread depth is maintained across the entire width of the tread face. Competition tires are typically molded with a tread depth of 5/32” to 6/32” and should not need shaving. Street tires are typically molded with tread depths of 8/32” to 10/32”. Tire manufactures recommend shaving street tires to a depth of 4/32” to 5/32”when used for competition. In all cases, tires must have 2/32” minimum tread depth at all times during competition.
  6. Treaded tires of minimum 60 series aspect ratio must be used unless an exception is specifically granted by the BoD. Measured tread width will be used to determine aspect ratio.
  7. Heads must conform to practice of the period year and be OEM with a casting number available before or during 1972. For guidance please see a group representative. Chevy 034 Bow Tie heads are permitted as substitution for 492 angle-plug family heads in AS/TA through the 2010 season, but not in 2011 and beyond.
  8. No roller cams are allowed.
  9. Aftermarket blocks are allowed provided they are of the same material as OEM and critical dimensions are the same.
  10. Aftermarket engine internals are allowed.
  11. A Sedan dry sump tanks must be mounted forward of the firewall.
  12. Intake manifolds must be OEM, period aftermarket, or of period design. For V-8 cars, aftermarket manifolds must be of period design, non-air gap, and dual plane.
  13. Specifically excluded are aftermarket dog-ring transmissionsor transmissions that have been modified to accept Hewland type gearsthat may be shifted without using the clutch.
  14. Aftermarket rotors may be used provided they are the same diameter as originally provided and period caliper reused and mounted in period location.
  15. Modern electronic ignition allowed. No crank-fire igniton.
  16. SFI-approvedaftermarket engine damper/balancer is recommended. No point deduction.

CVAR FIA/IMSA Class Rules

CVAR FIA/IMSA class includes naturally aspirated cars that were raced before or during 1974 in FIA groups 2, 3 or 4, IMSA or RAC Modsports. (FIA group-5 is classified as ASR in CVAR.) Cars must have period race history and be run in period configuration, or be an exact clone of a historical racecar using a brand-authentic car base.

  1. Clones must faithfully emulate a specific car as raced, exhibiting the same combination of bodywork, engine, transmission, brakes, and wheels packaged in period.
  2. All clones must start with an authentic manufacturer chassis.
  3. No replicas or continuations.
  4. No mixing and matching configurations between model variants.
  5. Paint and trim are free.
  6. No turbos or superchargers.
  7. No tube frames.
  8. Must meet minimum weight as raced in period.

Entrants must provide documentation of proper specifications and pictures of the exemplified car when CVAR does not already have such information. If you present a car for FIA, it is your responsibility to show it has the same look (except color/graphics) and mechanical specifications as run in period. Above all else, the entrant must be able to carry on an informed conversation about his car with an honest and reasonable explanation for any attribute of his specimen of automotive history.

FIA/IMSA Exceptions

  1. Allow any tire (slick or treaded) that fits authentic rims and flares.
  2. Allow OEM heads that retain original design, appearance, dimensions, material, port spacing, flow, and valve diameter, with intent to replicate period performance.
  3. Allow aftermarket replacement blocks that retain original design, appearance, dimensions, and material, with intent to replicate period performance.
  4. Allow aftermarket engine internals with original dimensions.
  5. Period-correct carburetors may replace mechanical fuel injection.
  6. Maximum overbore from stock is 0.060”.
  7. Allow roller rockers.
  8. Dry sump allowed in any car.
  9. MSD or other electronic ignition allowed, but no crank fire.
  10. Allow substitution of single-plug ignition in place of twin-plug
  11. Allow roll cages through firewall or bulkhead.
  12. Cosmetic body panels attaching to the original chassis may substitute fiberglass for metal.
  13. Lexan allowed in place of glass.

FIA/IMSA Guidance

Our intent is to replicate, not reinvent, history. If we are doing our job right, finishing order should resemble history. If you want to go fast, pick a fast car in period, and prepare it faithfully. Do not boost performance with modern technology. As of September 2008, we have information on:

  • Panteras
  • Jaguars
  • Porsche 72 ST, 73 RS, 73 RSR, 73 IROC, 74 RS and 74 RSR
  • 68-74 (C3) Corvettes

You can prepare a car to one of those specifications or provide data for another model raced before or during 1974. Examples of documentation on file for existing cars are:

  • letters from original owners providing specifications and pictures
  • race results from the period
  • copies of rules that the car ran under
  • builder’s notes describing equipment used
  • magazine articles or periodicals about the specific car
  • copies of bills of sale showing ownership succession, etc.

Simply providing a picture of a car running on some track somewhere with no other documentation does not qualify.

General Criteria for Sports Racing Cars

  1. Cars must be an example of cars raced prior to 1973.
  2. Owners must provide proof of date of manufacture of identical model and appropriate specifications.
  3. English Clubman cars must run with fenders.
  4. May gusset frame members for safety reasons. No additional tubing may be added that was not done in period.

General Criteria for Formula Cars

  1. Owners must provide proof of date of manufacture of identical model.
  2. Identical models must have been raced in or before the cut-off year.
  3. May gusset frame members for safety reasons. No additional tubing maybe added that was not done in period.

Return to Rules.