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Contents:

1. General Regulations

2. Production Category

3. SCCA Sports Racing Category (Group 7)

4. Formula SCCA

5. Formula VEE

6. SCCA Sedans

7. Formula F (Ford)

1. General Regulations

1.1 Eligibility

To compete in an SCCA-sanctioned event, cars shall meet the following requirements as well as the specifications of the class and category in which they are entered.

1.2 Fuel

All cars shall use pump fuel as defined in GCR 2.11 unless a specific exception is made in the rules for a particular category of automobile.

1.3 Identification Marks

Each automobile shall carry identification numbers, class letters, or other marks required by the supplementary Regulations. Numbers shall be placed on the front, rear and both sides of each automobile so that they are legible. Numbers used shall be restricted to one or two digits and shall meet the approval of the Chief Timer and Scorer.

The Supplementary Regulations shall ordinarily require all automobiles to carry black numbers at least eight to ten inches high with 1.5-2" stroke on white background.

1.4 Advertisements on Automobiles

Advertising, names and symbols may be displayed on cars provided they are in good taste, do not interfere with identification marks, and do not exceed a total area of 200 square inches.

1.5 Mechanical condition of Automobiles

The Chief Technical and Safety Inspector shall have the responsibility for inspecting and certifying every automobile before it is allowed to take part in a competition or practice. An automobile which is disapproved, or which is driven in a competition or practice, or which is presented for recheck without the corrections specified by the Chief Technical and Safety Inspector may be disqualified from the event.

Automobiles which have been altered or damaged after they have been approved at technical and safety inspection shall be subject to reinspection and approval.

All major body components such as front and rear hoods, fenders, doors and wind screen must be maintained in normal position throughout the competition.

1.5.1 Technical and Safety Inspection

The points covered at technical and safety inspection shall be:

1. Eligibility for class entered -- compliance with the GCR.
2. Suitability for competition.
3. Appearance--neat and clean. Specifically, automobiles that are dirty either externally or in the engine and passenger compartments, or that show bodywork damage, or that have not undergone proper repairs after any damage, or that are partially or totally in primer, or that do not bear the prescribed identification marks shall not be approved for competition.
4. Racing Tires -- designated as such by the manufacturer, or recaps on such racing tires shall be required. Racing slicks are prohibited.
5. Brakes -- shall be pedal-operated, working directly on each wheel, and in perfect working order.
6. Fenders -- shall be securely mounted. Fender skirts and hub caps shall be removed.
7. Exhaust system -- shall exhaust gasses away from the body and to the rear of the driver. Closed cars shall run with at least one window open, or provide other ventilation.
8. Hood and engine compartments -- all parts shall be securely fastened.
9. Front suspension and steering -- shall be of suitable design and in proper order.
10. Leakage and caps -- no leakage of any fluid shall be allowed.
11. Signal lights -- each car shall have operating brake and tail lights, except for formulas SCCA, F, and Vee.
12. Seats -- shall be securely mounted.
13. Seat belts and shoulder harness conforming to the specifications of Appendix Y of the GCR.
14. Passenger seat back -- if a folding seat, it shall be securely bolted or strapped in place.
15. Roll bars -- each car shall be equipped with a roll bar to specifications of Appendix Z of the GCR.
16. Tonneau covers are prohibited.
17. Fire wall and floor -- shall prevent the passage of flame and debris to the driver's compartment. Belly pans shall be vented to prevent accumulation of liquids.
18. Mirrors -- shall provide driver visibility to the rear of both sides of the car.
19. Fire extinguisher -- shall be securely mounted in the cockpit, shall be dry chemical type of at least two-pound capacity. (On formula cars, extinguishers may be mounted in an accessible location outside the cockpit.
20. Flame resistant garments, crash helmets, goggles, or face shields -- shall be approved at safety inspection and may also be checked upon the starting grid (Ref. GCR 4.8)
21. Headlights -- shall be protected to prevent shattering.
22. Scatter-shields -- The installation of scatter-shields or explosion-proof bell housings shall be required on all cars where the failure of the clutch or disintegration of the flywheel could create a hazard to the driver.
23. Detachable hardtops -- shall be removed.
24. Oil catch tanks -- All engine crankcase breathers shall be quipped with oil catch tanks.

2.1 Definition

1. The purpose of the Production Category shall be to provide a Club-wide program of speed events for the benefit and pleasure of SCCA members who desire to compete in series-produced sports cars, generally available for purchase by the public, and suitable for both normal road use and speed events participation, and who additionally desire to improve the performance of these cars within specific and uniform preparation limitations.
   

The SCCA shall publish a list of sports cars eligible to compete in the Production Category during the current calendar year. After this list has been established, no changes or additions in classification shall ordinarily be made.

2. Production Category automobiles shall normally be those which are series-produced with normal road touring equipment in quantities of a least 500 within the last 12 month period. However, the SCCA may exclude an automobiles from the Production Category even if made in greater quantities, if such automobiles are not considered suitable.
   
3. Production Category automobiles shall be recognized according to the manufacturers’ complete designation, including the name, model, model number and engine displacement.
   

The SCCA shall publish the Production car specifications containing the official recognized specifications for each car eligible to compete in the Production Category during the calendar year.

4. Production Category automobiles must be raced as they are normally delivered to the public through the manufacturers’ sales outlets, except that they may be up-dated or back-dated within the specifications of a recognized make and model, as listed on a single page of the SCCA Production Car Specifications and except for the modifications authorized by these Rules.
   
5. The SCCA shall publish the specifications for each recognized Production Category model. This specification shall state the weight for each model, which weight shall normally correspond to the official weight listed on the model’s recognition form, or else shall be obtained by taking the weights of a number of examples of the same model, selected at random, and weighed under the following conditions: With the spare wheel and tire for the size normally provided by the manufacturer, with full oil sump (or tank), and with full water tank if one is used but without fuel, tools, luggage or anyone aboard.
   

A weight tolerance of minus 5% as compared with the official weight will be granted Production Category automobiles, provided the reduced weight results from modifications permitted in these rules. Cars must meet or exceed the official weight less 5% as raced, but without fuel and driver.

6. Production Category automobiles shall be classified for racing purposes in groups of cars of similar performance.
   
7. Production Category automobiles shall use Pump Fuel as defined in GCR Rule 2.11.
   
8. On closed Production Category cars, at least one main door window must e fully open during competition.

The following modifications are authorized on all Production Category cars: (Modifications may not be made unless specifically authorized herein)

1. Fitting all accessories, gauges and indicators, and all inside modifications for the purpose of improving the comfort and convenience of the driver and passenger and to permit the installation of required safety equipment, provided they have no influence whatever on the mechanical performance and do not materially reduce the weight of the car. Floor mats may be removed. The removal of interior trim (gutting) is not permitted. The driver's seat may be replaced with any suitable seat. Passenger seats may not be substituted. Seat head rests may be removed.
   
2. Raising hood for ventilation of engine compartment by use of hinge adjustment mechanism as installed by manufacturer. (Hood blocks or other modifications are not allowed). Additional hood straps or fasteners may be used. It is specifically not authorized to alter or open any hood, deck, or other body panels for purposes of additional ventilation. Sealing or shrouding the air flow area between the normal grill opening and the water radiator is permitted.
   
3. The use of any gas cap is permitted. One-way, anti-surge gas caps are recommended.
   
4. The top may be removed from open cars or else must be folded and securely fastened.
   
5. Windshield on open cars may be folded or removed provided a suitable aero screen is fitted. However, the entire windshield (i.e. both halves if a divided windshield) including all brackets and mounting fixtures must be removed if this substitution is made. Window glass and projecting hardware which might prove hazardous may be removed from the doors. The windshield wiper mechanism must remain in stalled as originally delivered, but the arms may be detached if necessary when he windshield is removed.
   
6. Bumpers may be removed, but if so, all projecting hardware such as brackets and fixtures must also be removed. No substitute bumpers are allowed. Hub caps and fender skirts must be removed. Grills may not be removed.

1. The make and size of tires provided they fit the rims without change or additions and do not interfere with the bodywork under any conditions of steering lock or rebound. In order to provide clearance for wheels and tires, the interior of fenders may be altered but not substituted with an alternate material. The authorized modifications may not result in any additional openings between the wheel well and the engine, passenger or luggage compartments. No modifications may be made to the exterior of fenders or the fender opening.

The tire tread may not extend beyond the fender opening at the highest point of the tire with the camber angles specified by the vehicle manufacturer for normal road use.

Spare tires may be removed, unless the Supplementary Rules for an event specify otherwise.

2. The use of any wheels of the same diameter and with a rim no more then 1.5 inches wider than the standard wheel listed by SCCA for the automobile. Changes in track resulting from the above wheels may not exceed plus or minus 2 inches from the track dimensions listed by SCCA for the automobile. (measured with the standard camber angle specified by the vehicle mfgr.) Furthermore, the track dimensions shall remain equally disposed from the centerline of the automobile.

The use of center-lock wheels and hubs is permitted within this track restriction.

3. The make and type of shock absorbers, but not their numbers, or their system of operation (i.e. lever or telescopic), or their system and points of attachment.
   
4. The cooling of brakes by ventilation of backing plates or fitting of air ducts, provided no changes are made in the bodywork above a plane passing through the wheel hubs.
   
5. The make of brake linings and the fitting of dual master cylinders.
   
6. The modification or substitution of front spindles and/or rear axle shafts, and modifications or substitutions of hubs, bearings, bearing carriers, universal joints, and drive shafts. These changes may not result in any changes in tread dimensions as measured from the centerline of the car, or any changes in other suspension components, or the suspension geometry.
   
7. The use of alternate suspension bushings of the same type and size.
   
8. The addition or substitution of any anti-sway bar, camber compensating device and/or axle locating device provided there is no other change in the standard suspension or drive-train components except as authorized elsewhere in these rules.
   
9. Springs or torsion bars of any kind may be replaced by others of unrestricted origin, but without changing the number supplied by the manufacturer and on the condition they an be fitted without alteration to the original supports and points of attachment. Spacers (lowering blocks) may be used between leaf springs and the points of attachment to the axle housing.
   
10. The removal of the handbrake and operating mechanism.

1. Make of spark plugs and ignition coil on condition that the system of ignition remains the one provided by the manufacturer. Transistor ignition is permissible provided the original distributor equipment is utilized.

An alternator may be used in place of the generator. Nothing must be done to interfere with he normal battery charging function of the generator or alternator.

2. Make or size of battery provided its voltage remains the same.

1. Induction System

1. Carbureted engines: Any alteration to the carburetors except changing the number, model, type, size (measured at the throttle butterfly) or butterfly location of the standard equipment and except that extensions or the addition of material to the exterior of the carburetor body is prohibited.
2. Fuel injected engines: Any alteration to the standard fuel injection components except:

• Changing the location, type, or number of air throttles (butterfly, slice, etc) or changing the inside dimensions of the air duct at the air throttle.
• The addition of material to the intake manifold.
• Changing the number or location of the injection nozzles.
• Changing the make and model of the fuel metering and/or fuel distribution unit. The fuel metering and/or fuel distribution unit may be modified without restriction provided that it can be positively identified as that fitted as standard equipment.

Velocity stacks (air intake horns) may be used on any induction system provided no modifications are made to the body or frame of the car to accommodate their use. Air cleaners may be removed.

2. Additional fuel pumps may be used provided they are only for supplying fuel to the carburetors and not for cooling purposes. If the mechanical fuel pump is replaced, a blanking plate may be used to cover the original mounting point.
   
3. Alterations to the fuel lines are permitted between the firewall and the engine. In addition it is permitted to install a fuel pump in the fuel line between the fuel tank and the firewall.
   
4. It is permitted to lighten, balance, or modify in shape by tooling the series-produced and recognized components of the engine and drive-train, provided it is always possible to identify them positively as such; it is not permitted to add any material or mechanical extension. The engine fan may be completely removed.
   
5. Additional shims required for valve adjustment or for maintaining the geometry of a valve train after machining operations will be allowed.
   
6. The use of alternate engine and drive-train components which are normally expendable and considered replacement parts such as seals, bearings, valves, valve guides and valve seats provided they are the same type and dimension. Bushings may be installed where none are fitted as standard.
   
7. Compression ration may be increased by machining, using a thinner gasket, or doing without one.
   
8. Reboring the cylinders is authorized on condition that the greates bore measurement specified for that make and model is not exceeded by more than 1.2mm (0.0472 in.).
   
9. Substitute pistons of any material or origin are authorized.
   
10. The substitution or addition of any valve springs of the same basic type (i.e. hairpin or helical) with which the car is normally equipped is authorized, and the substitution or addition of keepers and retainers.
    
11. The use of any exhaust manifold and exhaust pipe.
    
12. The addition of any single engine oil filter.
    
13. The ratios of the gar box and rear axle when listed by the SCCA. Addition of a device for locking out reverse gear.
    
14. Installation of any type of vent or breather on the engine, transmission, or differential to prevent loss of lubricant and the use of oil catch tanks.
    
15. Any modifications to the clutch except changing the diameter of the unit originally specified for the model by the manufacturer.
    
16. The use of any limited slip differential, expect that no substitution of the differential housing is permitted.
    
17. Springs or torsion bars of any kind may be replaced by others of unrestricted origin, but without changing the number supplied by the manufacturer, and on condition they can be fitted without alteration to the original supports and points of attachment.
    
18. Use of any pushrods.
    
19. Use of any oil pan (sump) and/or oil pump pickup.
    
20. Use of any water radiator provided the standard radiator mounts are retained and there are no changes in body, chassis, or internal structure of the car to accommodate its use. Separate expansion tank provided it is mounted within the engine compartment.
    
21. On water cooled cars, thermostats may be modified, removed or replaced with blanking sleeves or restrictors.
    
22. Generator, crankshaft and water pump pulleys may be altered or replaced with others of unrestricted origin.
    
23. Use of any external crankshaft vibration dampener is allowed.
    
24. Use of any single differential oil cooler and/or single engine oil cooler provided it (they) are mounted completely within or under the coachwork but not within the driver/passenger compartment. An oil pump may be added for the differential oil cooler.

Air ducts my be fitted to the oil coolers(s) provided they do not extend more than 12 inches in any direction from the cooler fins.

25. The use of any flywheel provided the diameter is the same as the unit originally specified for the model by the manufacturer and provided the crankshaft attachment points are not changed.
    
26. Exhaust emission control air pumps and associated lines and nozzles cannot be modified in any way except that they may be completely removed. When these air nozzles are removed from a cylinder head, the holes must be completely plugged.

 E. Safety Fuel Tanks

1. General
   

Fuel tanks in Production Category crs may be substituted with safety fuel tanks conforming to the SCCA safety fuel tank standards. Such safety fuel tanks must be produced by manufacturers specifically approved by the SCCA and shall be of the standard dimensions and capacities below:

22 Gallon	W 17"	L 33"	H 9"
15 Gallon	W 17"	L 24"	H 9"
8 Gallon	W 12"	L 20"	H 9"

Bladder type tanks shall utilize a container of 20 gauge steel (min.) -- add 1/4" to each dimension above for maximum outside dimension of the container.

2. Capacity
   

There shall be no restriction of fuel capacity when installing safety fuel anks and the installation of more than one of the standard 22, 15 or 8 gallon fuel tanks is permitted.

3. Location
   

Location of the safety fuel tank shall be as close as possible to the location of the standard tanks(s) except when safety aspects or dimensional limitations make this unfeasible or impossible. In no case shall the location of the center of gravity of the safety tank in the automobile be more than 12" from the center of gravity of the standard tanks(s), nor shall the tank be located in the driver/passenger compartment.

4. Installation, Fittings, Lines

In 1967 Production Category automobiles shall be divided into classes based on relative performance as follows:

• Abarth Simca 2000
• AMX Sports Coupe 390 through 1969
• Shelby Cobra 427
• Corvette Sting Ray 427 through 1967
• Corvette Sting Ray Roadster 427 1968
• Corvette Sting Ray Roadster & Coupe 427 1969
• Griffith 200
• Porsche GTS/904
• Shelby GT-500 through 1967
• Shelby GT-500 1969 - Coupe
• Sting Ray 396

• AMX Sports Coupe 290 through 1969
• AMX Sports Coupe 343 through 1969
• Aston Martin DB4
• Aston Martin DB5
• Aston Martin DB4 GT & GT Zagoto
• Shelby Cobra 289
• Corvette 327
• Corvette 283
• Corvette Sting Ray 327 through 1967
• Corvette Sting Ray Roadster 327 1968
• Corvette Sting Ray Roadster & Coupe 350 1969
• Ferrari 250 GTO
• Ferrari 275 GTB
• Ferrari Berlinetta Lusso
• Ferrari 250 GT – SWB
• Ferrari GT – California, Coupe, & Cabriolet
• Ferrari 2+2
• Jaguar E 3.8 & 4.2
• Porsche 911E Coupe/Targa Cabriolet 1969
• Porsche 911S Coupe/Targa Cabriolet 1969
• Shelby GT-350 through 1966
• Shelby GT-350 1-4V 1967
• Shelby Cobra GT 350 Coupe 1969

• Abarth Simca 1300
• Alfa Romeo TZ
• Datsun SRL 311U (Nikuni)
• Ginetta G4-1500
• Lotus Elan through S4 (Roadster, Coupe, Drophead)
• Lotus Elan Plus Two
• Mercedes Benz 300 SL
• MGC, MGC GT
• Morgan Super Sports
• Osca 1600 GT
• Porsche Carrera 1500, 1600
• Porsche 356B, C 2000 GS
• Porsche 911, 911S, 911L (Coupes) through 1968
• Porsche 911T Coupe/Targa -- Cabriolet 1969
• Sunbeam Tiger 260
• Toyota 2000 GT
• Triumph TR-5
• Triumph TR-250
• Triumph TR-6 (F.I.)
• Triumph TR-6 (Stromberg)

Class D

• AC Ace Bristol ACECA Bristol
• Alfa-Romeo 2600 Sprint & Spider
• Alfa-Romeo Duetto 1750?
• Arnolt Bristol
• Austi-Healey 3000
• Daimler SP250
• Elva Mk. III 1800 & Mk. IV 1800
• Elva Mk. IV T1800
• Fairthorpe Electron
• Fiat Abarth 1000 DOHC
• Ginetta G4-1000
• GSM Delta
• Jaguar XK 120, 140, 150
• Lotus Super Seven
• Lotus Mk 46 Europa
• Marcos GT 1000
• Mercedes Benz 280 SL
• SAAB Sonet V-4
• Speedwell GT 2A, 2B
• Triumph TR-4
• Triumph TR-4A – IRS
• Turner Climax
• TVR Mk. III 1800
• TVR Climax
• Yenko Stinger 

• Alfa Romeo Duetto 1600
• Alfa Romeo Giulia Spider Veloce 1600
• Alfa Romeo Giulia Sprint GT & GTC
• Alfa Romeo Giulia Sprint Speciale
• Austin-Healey 100-6
• Elva Mk. IV T Ford
• Elva Mk. I, II, III, 1622
• Elva Mk. IV 1622
• Fairthorpe Electron Minor
• Lotus Elite
• Mercedes Benz 250 SL
• MGB, MGB GT
• Morgan +4
• Porsche 912 through 1968 -- Coupe
• Porsche 912 Coupe/Targa -- Cabriolet 1969
• Porsche 356C/1600SC & 356B Super 90
• Porsche 356 1500/1600 A, B, C
• Triumph TR-2, 3, 3A, 3B
• Turner 1500
• TVR Mk. III 1622
• TVR Vixen 1600 Ford
• Volvo 1800 (1990 cc) 1969
• WSM GT

 Class F

• Alfa Romeo Giulietta Super 1300
• Alfa Romeo Giulietta Sprint Speciale
• Alfa Romeo Giulia Sprint & Spider 1600
• Alfa Romeo Spider 1300 Junior
• Alpine A110-1100
• Austin Healey 100-4
• Austin Healey Sprite 1275
• Datsun SPL-311 & SPL-311U
• Fiat 124 Sport Spider
• Fiat Abarth OT 1300/124 Coupe
• Glas GT 1700
• Lotus 7 & 7 America
• Mercedes Benz 230 SL
• MGA Twin Cam
• MGA 1500, 1600, 1622
• MG Midget 1275
• Morgan 4/4 Mk. V
• Sabra Sport
• Sunbeam Alpine
• Triumph Spitfire Mk III 1300
• Volvo P1800 (1780 cc)

• Alfa Romeo Sprint & Spider 1300
• Abarth OTS 1000 Coupe
• Alpine A108-1000
• Austin-Healey Sprint 1100
• Austin-Healey Sprint AN8
• Datsun SPL 310U
• Fiat Abarth 700, 750 DOHC
• Fiat Abarth 1000 Pushrod
• Fiat Abarth OT 1000 Spider
• Fiat 150 Spider DOHC
• Fiat 1500 Spider & Cabriolet
• Glas 1300 GT
• Hond S800
• Matra
• MG Midget 1100
• MG Midget AN 3
• Porsche 1300
• Rene Bonnet CRB
• Triumph Spitfire Mk I & II
• Turner 950S

• Austin Healey Sprite 948 Mk I & II
• DB HBR5 851-954
• Fiat 850 Spider
• Fiat 1200 Spider
• Fiat Abarth 850S, 750GT, 750MM
• Honda S600
• MG Midget 948
• MG TC, TD, TF 1250
• MG TF 1500
• Morgan 4/4 Mk IV
• NSU -- Wankal -- Spider

3.1 General

3.2 Classification

Classification of cars shall be according to engine displacement as follows:

A -- Over 2000 cc
B -- Over 1300 cc and below or equal to 2000 cc
C -- Over 850 cc and below or equat to 1300 cc
D -- Below or equal to 850 cc

Supplementary regulations for an event or series of events may provide for combining any of these classes

Supercharged cars shall be classified according to their displacement times a factor of 1.4.

Special Engines

Cars with special engines shall be classified according to a displacement equivalent determined as follows:

Rotary Piston Engines:

Cars with rotary piston engines covered by the NSU-Wankel patents shall be classified on the basis of a piston displacement equivalence of twice the volume determined by the difference between the maximum and minimum capacity of the working chamber.

Turbine Engines:

Cars with Turbine engines shall be classified on the basis of a displacement equivalent formula and shall be limited to a maximum equivalent displacement of 3000cc.

The formula is as follows:

          C x 0.09625

A = ------------------

       (3.10 x R) - 7.63

A = High-pressure nozzle area--expressed in square centimeters--by which is meant the area of the air-flow at the exit fromt he stator blades (or at the exit from the first stage if the stator has several stages).  Measurement is done by taking the minimum area etween the fixed blades of the high pressure turbine first stage.  In cases where the first stages turbine stator blades are adjustable, they will open to their greatest extent to present the greatest area for the determination of area "A".

The area of the high pressure nozzle is thus the product--expressed in square centimeters--of height by width and by the number of vane spaces.

C=Cylinder-capacity of the alternating piston engine expressed in cubic centimeters (formula 1:3000 cc)

R=The presure ratio, i.e. the ratio of the compressor of the turbine engine.  This pressure ratio is obtained by multiplying together a value for each stage of the compressor, as indicated hereafter:

• Subsonic axial compressor = 1.15 per stage
• Supersonic axial compressor = 1.5 per stage
• Radial compressor = 4.25 per stage

Thus a compressor with one radial and siz axial stages will be designated to have a pressure ratio of:

4.25 x 1.15 x 1.15 x 1.15 x 1.15 x 1.15 x1.15  (or 4.25 x 1.15^6)

3.3 Self Starter

Engines shall be started with an automatic self starter and on-board power supply.  Any other method of starting the engine at the start or during a competition is prohibited.

3.4 Brakes

These cars shall be equipped with a dual braking system operated by a single control.  In case of a leak or failure at any point in the system, effective braking power shall be maintained on at least two wheels.

A separate hand brake (emergency brake) is not required.

3.5 Coachwork

Coachwork shall provide comfort and safety for driver and a passenger.   All elements of the coachwork shall be completely and neatly designed and finished, with no temporary or makeshift elements.  The body shall cover all mechanical components, except that the intake and exhaust pipes may protrude.

a. Cockpits and Seats --

There shall be seats for the driver and a passenger of equal dimension and comfort, and equally disposed on each side of the longitudinal axis of the car.   Seats shall be firmly attached in the car, but may provide for adjustment for the size of the occupant.

The passenger's space and seat shall remain available throughout the competition and shall not be encroached upon by any element of the car or equipment except as provided in these rules.

The passenger's compartment and seat shall not be sheltered by means of a tonneau cover of any type.

Driver and passenger space shall satisfy the following minimum dimensions:

The inside minimum width of the compartment shall be 40 inches measured at the immediate rear of the steering wheel hub and at right angles to the longitudinal axis of the car, and must be unobstructed and maintained at least 10 inches in a vertical plane.

Seats must fulfill the following minimum dimensions:

a is always measured horizotally and parallel to the longitudinal axis of the chassis, between two vertical planes perpendicular to the longitudinal axis and defining from front to rear the open space on a level where such measurement is taken.

For the driver's seat, a is measured on the floor level, or at the bottom of any recess if need be, from the perpendicular of the furthest pedal in its position of rest.

For the passenger seat, this measurement is taken at a height of 8 inches above the floor, or at the bottom of the recesses, if need be.

In case of movable seats it is forbidden to alter the position of any seat while the car is being measured.

b is measured vertically from the rear of a to the horizontal plane tangent to the highest part of the cushion as shown on the drawings.

c is measured, in the horizontal plane defined above from the upper end of b, parallel to a, and tangent to the foremost point of back of seats.

The arrangement of body must be such that:

a + b + c = 43 in minimum

The minimum width for the foot space for each person must be 10 inches measured at right angles to the longitudinal axis of the chassis.

b. Windshield --

All cars shall be equipped with a windscreen constructed of transparent material which shall provide equal and adequate protection for both the driver and passenger at all speeds.  Windshield wipers are not required.

c. Visibility --

Coachwork shall provide visibility for driver and passenger forward and to both sides adequate for racing conditions.  Rear view mirror(s) shall provide driver visibility to the rear of both sides of the car.

d. Doors --

Coachwork shall provide at least two rigid doors, thereby giving direct access to each of the seats.  Each door shall accept a rectangle held in a vertical plane of at least 12 inches x 20 inches.  These dimensions shall not include any area above the horizontal plane of the body and door panels.  The door openings may not be obstructed in any way.

e. Fenders --

Fenders shall be firmly attached to the coachwork with no gap between body and fender

Fenders shall be placed above the tires and shall cover them effectively by surrounding at least a third of their circumference.  The rear of each fender shall not be higher than a horizontal line passing through the axis of the wheel.   The width of each fender shall extend beyond the side of the tires when the wheels are parallel to the longitudinal axis of the car.

In case the fenders constitute a part of the body, or are partly overhung by the structure of the body, the combination of fenders and body, or the body alone, shall meet the above requirements.

f. Loss of coachwork --

All major body components such as front and rear hoods, fenders, doors, and windscreen must be maintained in normal position throughout the event.

3.6 Wheels and Tires

There shall be no restriction on the size of wheels or tires, provided thay are identical for the right and left front axles, and identical for the right and left rear axles.

A spare wheel and tire are not required.

3.7 Safety Equipment

a. Fire extinguisher --

All cars shall carry during competition a dry chemical fire extinguisher of at elast 2.5 lbs capacity.  It must be securely mounted and may be located in the space provided for the a passenger.

b. Scatter Shields --

The installation of a scatter shield is required on those cars where the failure of the clutch or flywheel could, due to its location, create a hazard to the driver.  In addition, any rotating part of the drive train shall not pass openly through the driver and passenger compartment, but must be under the floor or fitted in tubes or sasings firmly attached to the floor or chassis structure.

c. Roll bars --

Cars shall be equipped with a roll bar or structure to protect the driver in case the car overturns.  It shall be firmly attached to the chassis structure and designed to withstand compression forces from the weight of the car as well as fore-and-aft loads from hirizontal forces.  Size, construction, and installation shall conform to current SCCA specifications.

d. Seat belt --

The car shall be provided with a 3 inch width safetly belt of the metal-to-metal quick release type attached to the chassis structure designed to restrain the driver in his seat.

e. Exhaust system --

The exhaust system shall terminate behind the driver and passenger seats.

f. Firewall and floor --

Cars shall have an adequate firewall to prevent the passage of flame from the engine compartment or under the car to the cockpit.  Openings in the firewall for the passage of engine controls, wires, and lines shall be of the minimum size necessary.

The floor of the cockpit shall be constructed to protect the driver by preventing the entry of gravel, oil, water, and debris from the road and engine.   Bottom panels or belly panels shall be adequately vented to prevent the accumulation of liquids.

g. Bulkheads and Tanks --

No part of any fuel, oil, or water tank shall be exposed to any part of the driver and passenger compartment.  Fuel tanks shall be vented to prevent the accumulation of fumes and to prevent fumes from passing into the driver or engine compartment.

Safety fuel tanks of a type comparable to those currently available from Firestone and Goodyear re highly recommended in all cars, and are required equipment in USRRC and Canadian-American Challenge Cups competition.

Fuel tanks shall be isolated by means of bulkheads so that in case of spillage, leakage, or a failure of the tank the fuel will not pass into the driver or engine compartment of around any part of the exhaust system.

Batteries shall be enclosed in a covered battery box to prevent leakage or spillage of fluid and shall be firmly attached in the car.

h. Closed cars --

Adequate ventilation shall be provided to prevent the accumulation of fumes inside the car.

4.1 Class A

A. General

1. A single seat, for open-wheeled racing car with firewall, floor, and safety equipment conforming to the GCR.
2. Cars must be equipped with on-board self starter controlled by the driver in normal driving position.
3. The driver's seat must be capable of being entered without the removal of manipulation of any part or panel.
4. Cars shall be equiped with a dual braking system operated by a single control.  In case of  a failure or leak at any point in the system, effective braking power shall be maintained on at least two wheels.
5. No part of the frame or body shall project beyond a plane connecting the vertical centerlines of the front and rear tires.
6. Power may not be applied to more than two wheels.

B. Engines

1. 3000 cc unrestricted
   1. Engines of unrestricted origin over 1100 cc and below or equal to 3000 cc.
   2. Superchargers permitted on engines below or equal to 1500 cc.
   3. Rotary piston engines: cars with rotary piston engines covered by the NSU-Wankel patents will be admitted on the basis of a piston displacement equivalence.  This equivalence is twice the volume determined by the difference between the maximum and minimum capacity of the working chamber.
      
2. 5000 cc restricted
   1. Engines must be approved by the SCCA, of US manufacture, pushrod operated valve mechanism, and produced in quantities of at least 5000 per year.
   2. Engines may be modified or altered as desired except as follows:
      1. Maximum displacement shall be 5000 cc and may be obtained by alteration of bore and/or stroke as desired.
      2. Cylinder block and/or cylinder head(s) may not be substituted.
      3. The location of the camshaft may not be changed.
      4. The number of main bearings may not be changed.
      5. Superchargers are not permitted

C. Minimum Weight

(Minimum weights include coolant and lubricants; do not include fuel and driver)

• 3000 cc unrestricted engine cars             1105 lbs.
• 5000 cc restricted engine cars                 1250 lbs

D. Fuel Tank Capacity

• 3000 cc unrestricted engine cars             26 US gallons
• 5000 cc restricted engine cars                 30 US gallons

4.2 Class B

1. Single seat, four open-wheeled racing car with firewall, floor and safety equipment conforming to the GCR.

2. Displacement -- over 1100 cc and below or equal to 1600 cc.   Cars with rotary piston engines covered by the NSU-Wankel patents will be admitted on the basis of a piston displacement equivalence.  This equivalence is twice the volume determined by the difference between the maximum and minimum capacity of the working-chamber.

3. Engines -- shall derive from automobiles recognized by FIA in Appendix J Group 1 (Series Production Touring), Group 2 (Touring), or Group 3 (Grand Touring), and shall conform to definitions and specifications shown on the FIA recognition form of the homologated car.

   Modifications permitted shall be identical to those allowed for SCCA sedans (see Appendix A, section 6, 'SCCA Sedans').  Additionally, the following modifications are permitted:

   1. the use of any carburetor(s), fuel injection, or intake manifold(s).

   2. the use of any exhaust manifold(s).

   3. the use of any oil sump.

   4. the use of any oil pump.

   5. the use of a dry sump lubrication system.

   6. the use of any crank shaft of the stroke specified in the homologation forms for the engine.

   7. main bearing caps may be reinforced or substituted.

4. Transmission -- no more than five forward speeds.

5. Minimum weight in running conditions (i.e.--includes coolant and lubricants; does not include fuel or driver): 848 lbs.

6. Cars must use pump fuel only.

7. Cars must be equipped with on-board self starter controlled by the driver in the normal driving position.

8. The driver's seat shall be capable of being entered without the removal or manipulation of any part or panel.

9. Cars shall be equiped with a dual braking system operated by a single control.  In case of a leak or failure at any point in the system, effective braking power shall be maintained on at least two wheels.

10. Supercharging devices are not permitted.

11. No part of the frame or body shall project beyond a plane connecting the vertical center-lines of the front and rear tires.

12. Maximum fuel tank capacity: 19 US gallons.

4.3 Class C

1. Single seat, four open-wheeled racing car with firewall, floor and safety equipment conforming to the GCR.

2. Engine displacement below or equal to 1100 cc.  Cars with rotary piston engines covered by the NSU-Wankel patents will be admitted on the basis of a piston displacement equivalence.  This equivalence is twice the volume determined by the difference between the maximum and minimum capacity of the working-chamber.

3. Minimum weight in full runing conditions (i.e.--includes coolant and lubricants; does not include fuel and driver): 750 lb.

4. Cars must use pump fuel only.

5. Cars must be equipped with on-board self starter controlled by the driver in the normal driving position.

6. The driver's seat shall be capable of being entered without the removal or manipulation of any part or panel.

7. No part of the frame or body shall project beyond a plane connecting the vertical center-lines of the front and rear tires.

8. Cars shall be equiped with adual braking system operated by a single control.  In case of a leak or failure at any point in the system, effective braking power shall be maintained on at least two wheels.

9. Supercharging devices are not permitted.

10. Maximum fuel tank capacity: 16 US gallons.

5.1 Definition

A formula for signle-seat, open-wheel racing cars based on standard Volkswagen 1200 series type I, U.S. model sedan components, and restrictive in specifications so as to emphasize driver ability rather than design and preparation of the car.

No components, of the engine, power train, front suspension or brakes may be altered, modified, or changed, nor be of other than VW manufacture, unless specifically authorized.

5.2 Weight and Dimensions

• Minimum weight, without fuel or driver -- 825 lb
• Wheelbase, Minimum -- 81.5"
• Wheelbase, Maximum -- 83.5"
• Track, Front--Standard VW--51.4"
• Track, Rear--49.3" (±0.125") at zero camber
• Overall length, Minimum -- 123"
• Overall length, Maximum -- 127"
• Body depth at firewall, Minimum -- 25"
• Body width at firewall, Minimum -- 34"

5.3 Suspension

1. The front suspension and steering shall be standard VW sedan as defined herein.   The following modifications are allowed:
   
   1. Removal of one torsion bar.
   2. The use of any anti-sway bar(s).
   3. Use of any shock absorber which can be mounted on the standard mounts.
   4. Relocation of the steering gear box to a central position, and replacement of the tie rods with others of a suitable length.
   5. Steering columns may be altered and any steering wheel may be used
   6. Use of any desired Pitman arm.  Standard steering arms may be altered; however, no modification of the spindle is permitted.
      
2. The rear axle assembly shall be standard VW sedan as define herein with axle location provided by a single trailing arm on each axle.  Coil springs shall provide the primary springing medium, with telescopic shock absorbers mounted inside the springs.   Cables, straps, or other positive stops may be used to limit positive camber.   An anti-roll bar or camber control device may also be used.  When said anti-roll bar or camber control device is removed, the required coil springs must continue to perform functionally.
3. Wheels shal be standard 15" as used on the 1200 cc VW sedan as defined herein.
4. Any tire size may be fitted.

5.4 Brakes

1. Brake drums, backing plates and wheel cylinders shall be standard VW sedan, as defined herein.
2. These cars shall be equipped with a dual braking system operated by a single control.   In case of a leak or failure at any point in the system, effective braking power shall be maintained on at least two wheels.  Any master cylinder(s) may be used.
3. A separate hand brake (emergency brake) is not required.

5.5 Engine

The engine shall be a standard VW powerplant, as normally fitted to VW sedans as defined herein.

Allowed:

1. Removal of the carburetor air cleaner and choke mechanism.
2. Replacement of standard exhaust system with any exhaust terminating 1" to 3" behind the rear most part of the body.
3. Lightening of the flywheel to a minimum of twelve pounds.
4. Balancing of all moving parts of the engine, provided such balancing does not remove more material than is necessary to achieve the balance.
5. Polishing of the intake and exhaust ports, provided such polishing does not enlarge the exhaust port beyond 33mm inside diameter, and the intake port beyond 29mm inside diameter.
6. Matching of manifold flanges is permitted.
7. Removal of any cooling duct component.
8. Fitting of any standard VW carburetor originally supplied on above specified engines, and the use of any jets or VW venturi which may be fitted without alteration to the carburetor body.  The venturi must be fitted in the standard position.   Modification of the float is allowed as long as no change is made to the float chamber and/or float valve.
9. Fitting of any standard VW distributor.
10. Removal of the intake manifold heat riser tube.
11. Nothing must be done to interfere with the normal battery charging function of the generator
12. The installation of baffles housed completely within the original oil sump and case.
13. The use of an oil temperature indicating device in the crankcase.
14. The use of any standard VW oil pump.
15. The use of valve spring shims provided the fitted length of the spring is not less than the standard dimension.
16. The following starndard dimensions and tolerances of engine components are included as information and shall be observed:
    • Bore: 3.040"
    • Stroke: 2.520" ± 0.005"
    • Exhaust Valve Dia.: 1.102" or 1.18"
    • Intake Valve Dia.: 1.18" or 1.24"
    • Min Capacity of one combustion chamber in head: 43.0 cc
    • Min Depth, top of cylinder barrel to top of piston: 0.039"
17. The use of any VW clutch of the same diameter as fitted to standard VW sedan as defined herein.

5.6 Transmission-Rear Axle

The transmission-rear axle assembly shall be standard VW sedan as defined herein.   The synchromesh components muxt be in place and operating on at lease three gears.

Allowed:

1. Installation of any standard VW gear seet which can be fitted without modification of any components of the transmission or of the gear set itself and the transposing of the ring gear to provide proper axle rotation.
2. Removal of the handbrake linkage.
3. Alteration of the shock absorber mounts.
4. Transmission may not be installed in an inverted position.
5. The use of a limited-slip differential device is prohibited.

5.7 Ballasting

No ballasting is permitted.

5.8 Frame

The frame/chassis shall be constructed of steel tubing of a maximum diameter or width of four inches and be of a safe and suitable design.

There may be no frame/chasis rigidity or strength derived by means other than the frame tubes.  Stressed skin, monocoque or semi-monocoque construction is not permitted, except that:

1. The firewall panel may be rigidly attached to the frame tubes; and
2. The undertray (belly pan) may be rigidly attached to the frame, provided that the curvature of the undertray, measured vertically from its lowest point to the highest point of its attachment to frame members at its sides, may not exceed one inch.

5.9 Body

The body must enclose the engine by surrounding it from a point no higher than the lower edge of each valve cover and extending from the front of the engine to its rear on each side.  The top of the rear deck must extend from the back of the firewall to a oint in line with the rear of the transmission housing, but may have air intake openings.

The rear trailing arms, coil springs and shock absorbers may not be faired in by covering or shrouding them away from the airstream.  Specifically, the front mounting point or radius pad may be inside the trailing edge of the side body panel so long as the panel does not extend back over the trailing arm itself.

The drivers' seat must be capable of being entered without the removal or manipulation of any part or panel.  Firewall, floor and safety equipment must conform to the General Competition Rules of the SCCA.

No part of the frame or body shall project beyond a plane connecting the vertical centerline of the front and rear tires.

Air ducting may be utilized provided it is attached to the body or frame of the car.   Ducting may not be made part of or attached in any way to the engine assembly.

5.10 Allowed Replacement Parts

The use of the following non-standard VW replacement parts is allowed.  These parts must be normal replacement parts and shall not result in any unothorized modification of any other component.

Allowed:

1. Fasteners (nuts, bolts, screws, etc)
2. Wiring
3. Gaskets and Seals
4. Brake lines and fuel line
5. Spark plugs
6. Piston rings
7. Wheel bearings
8. Connecting rod bearings and crankshaft main bearings of same type and size as standard VW
9. Fan belt
10. Brake shoes and brake-lining
11. Valve guides

5.11 Battery

The use of any 6 volt battery is allowed

6.1.a Automobile Eligibility

SCCA Sedans shall be those makes and models of cars which are recognized and homologated as follows:

1. The SCCA shall recognize and publish a listing of those cars which are eligible as SCCA Sedans of over 2000 cc engine displacement.
2. The SCCA shall recognize SCCA Sedans those automobiles homologated by the FIA as Series Production Touring Cars (Group 1) or Touring Cars (Group 2), and which are of less than 2000 cc engine displacement.
3. Regardless of FIA or SCCA recognition as above, the following categories of cars shall not be eligible as SCCA Sedans:
   1. Cars with a wheelbase of more than 116"
   2. Cars with engine displacement of more than 5000 cc (305 cu in)
   3. Convertibles or sun roofs

6.1.b Recognition Form

All cars recognized by the FIA or the SCCA are described in detail on a Recognition Form, thereby enabling identification of the make and model, its specifications and approved optional equipment.  In order to be valid, the Recognition Form must carry the approval of the FIA or SCCA, whichever is applicable.

Entrants of SCCA Sedans must have in their possession the Recognition Form for the make and model entered, and shall make these forms available to the Scrutineers on request.  If the Recognition Form is not made available to the Scrutineers, the race officials may refuse to allow participation of that car.

In case of doub involving specifications not adequately described on the Recognition Form, the Scrutineers may refer to maintenance books, spare parts books, or general catalogs published by the amnufacturer for that make and model.

If a car is in cimplete compliance with its Recognition Form, the year of its manufacture is immaterial.

It is the responsibility of the competitor to obtain the complete Recognition Forms concerning his car.

1. In the case of cars less than 2000 cc engine displacement, these Forms are available from the National Automobile Club of the country in which the car is manufactured, or are available at $5 each from:

ACCUS, FIA

433 Main Street

Stamford, Conn 06901

2. In the case of cars over 2000 cc engine displacement, Recognition forms are available at $5 ea from:

   SCCA

   P.O. Box 791

   Westport, Conn 06880

6.1.c Disapproval

The SCCA may at any time disapprove the eligibility of any previously recognized make and model, or specification, or item of optional equipment.

6.1.d Conformance

Automobiles must conform entirely with the specifications and description contained in the Recognition Form.  For example, the engine specified in one model may not be used in another model even if the cars are of the same type and make.   However, the SCCA may at its discretion allow certain items of equipment to be interchanged between different models.  Such exceptions must be specifically approved and listed by SCCA to be valid.

6.2 Classes

Cars shall be classified according to engine displacement as follows:

1. -- over 2000 cc and below or equal to 5000 cc
2. -- over 1300 cc and below or equal to 2000 cc
3. -- over 1000 cc and below or equal to 1300 cc
4. -- below or equal to 1000 cc

6.3 Required Modifications

The following modifications are required on all cars competing in the SCCA Sedan Category.

1. All cars must meet the requirements specified in Appendix Z, Section 1.5.1 of the GCR.   It is recommended that all Sedans be equipped with a roll cage as described in Appendix Z, Section H of the GCR.
2. Fuel filler openings must be located to the outside of the body and in such a position that spillage will not enter the interior of the car.  The standard or optional fuel filler neck and cap may be replaced or modified, and for this purpose the coachwork may be modified as required.
3. At least one main door window must be fully open during competition.  An open vent does not suffice.
4. Under no circumstances may cars weigh less than the minimum weight specified on Recognition Forms, or in the caase of Class A cars, weigh less than 2900 lbs.  Weight of the car is as raced, but without fuel and driver.

It is specifically pohibited to perform an operatioon on the chassis or body for the purpose of lightening or changing shape, unless specifically authorized elsewhere in these rules.  This prohibition applies regardless of whether or not the car eceeds the minimum weight required.

5. There must be a metal bulkhead separating the driver compartment from the compartment containing the fuel tank.  Such bulkheads may be added if the standard vehicle has none.
6. Any steering system locking mechanism which ma be fitted by the manufacturer must be removed.
7. The following requirements apply to all cars entered in Trans-American Championship competitions:
   1. Cars must be equipped with safety fuel tanks meeting SCCA specifications. (See Appendix C)
   2. Standard bumpers may be removed as allowed elsewhere in these rules.  However, if removed, they must be replaced by substitute bumpers of identical appearance mounted in the standard location.  Parking lights mounted in the bumper may be removed, but the resulting hole in the bumper must be completely covered.

6.4 Authorized Modifications

A. General

1. It is not permitted to make any modifications, substitutions or alterations to the standard automobile and options as produced by the manufacturer in accordance with the Recognition Form for that car, unless such modifications are required under 6.3 of these rules, or authorized as follows.
2. In carrying out authorized modifications, it is not permitted to make any changes, alterations or modifications in any external element of the coachwork; that is, any part of the coachwork which is in the air stream and situated above a plane passing through the center of the wheel hubs.
3. Any springs on the automobile (such as valves, clutch, suspension, etc) may be replaced by others of unrestricted origin, but with no change in the number provided by the manufacturer and on condition they can be fitted without alteration of the original supports or attachments.
4. It is permitted to modify the arrangement, location and materials of all cables and pipes provided for the passage of fluid elements (air, water, fuel, electric current, etc.).  This rule also applies to the suspension system where applicable.

B. Chassis and Coachwork

1. Bumpers may be removed provided all projecting hardware also is removed.  Bumpers may be replaced by susbstitute bumpers of identical appearance mounted in the standard location.  Parking lights mounted in the bumper may be removed, but the resulting hole in the bumper must be completely covered.
2. Rear seat and seatback may be removed.  The passenger seat may be removed.   The driver seat may be replaced with anysuitable seat.  A racing type bucket seat providing lateral support for the torso is recommended.
3. Doors may be bolted or pinned to prevent their opening in case of accident.  Pins or straps may be added to engine hoods and trunk lids to suplment or replace the latches.   Standard hinges may not be removed.
4. Floor mats may be removed.
5. In order to provide cleaance for wheels and tires, the interior of fenders may be altered excepf for the removal wholly or partially of panels separating the wheel wells from the engine, passenger and/or lugage compartments.  The exterior contour of fenders may be altered to provide for tire clearance as long as there is no modification to the wheel opening and appearance is kept as nearly standard as possible.
6. The headliner may be removed.
7. Straps or clips for retaining wihdshields and rear windows in place are authorized and recommended.
8. Jacking points may be strengthened, their location may be changed or extra ones ma be added.
9. Headlight covers may be fitted provided they do not influence the streamlining of the car.
10. The steering wheel may be replaced and the rake of the steering column may be altered.
11. Inside door handles, window cranks and theshafts which protrude through the tim panels may be removed.  Te balance of the door and window operating mechanism may not be removed.
12. The replacement, addition, or removal of accessories, gauges, switches, indicators, and other interior modifications for the convenience of the driver and to permit the installation of required safety equipment is authorized, provided such modifications have no influence whatever on the mechanical performance of the car.  Such modifications do not include the substitution or replacement of any element of the coachwork or chassis (such as the dash).  All window glass must remain installed and may not be replaced with different material than supplied by the manufacturer nd listed on the recognition form.

C. Tires, Wheels, Suspension

1. Substitute wheels of any type or material may be used provided there is no change in wheel diameter or rim width, or in the resulting track dimension fromt hat specified on the Recognition Form. Rim widths may not exceed 8" on Class A (over 2-liter) cars and 7" on the Class B cars even if wider rims are listed on the Recognition form.
2. The spare tire may be removed.
3. The modification or substitution of front spindles and/or rear axle shafts, and modifications or substitutions of hubs, bearings, bearing carriers, universal joints, and drive shafts. These changes may not result in any changes in tread dimensions as measured from the centerline of the car, or any changes in other suspension components, or the suspension geometry.
4. The addition or substitution of any anti-sway bar is authorized. Traction master type torque rods, panhard rods, and other similar rear axle locating devices may be used.
5. The make and type of shock absorbers, but not their numbers, or their system of operation (i.e. lever or telescopic), or their system and points of attachment.
6. Suspension bushings may be replaced by others of a different material provided they are the same type and size.
7. Quick change/knock-off type wheels are not allowed even if included on the recognition form.
8. Spacers (lowering blocks) may be used between leaf springs and their points of attachment on the axle housinng.  The type and location of the axle mounting for the leaf spring is free.  Any leaf spring shackle may be used but it must be mounted to the chassis at the standard location.

1. The standard battery may be replaced by one of different make and capacity.   The voltage of the battery and electrical system may not be changed.  The battery location must remain in the coachwork compartment in which the battery is originally mounted.
2. The standard generator may be replaced by one of different make and capacity or by an alternator, provided the attachment location and the driving method remain unchanged.   Mounting brackets may be modified or replaced.  Any regulator may be used.
3. The make and location of the ingition coil and condenser may be changed.
4. Any distributor may be used provided its installation does not require any modification of the engine.
5. Transistor ignition is permitted provided its installation does not require any modification of the engine.
6. Any make or type of spark plug may be used.
7. Additional relays and/or fuses may be installed
8. The use of any starter is permitted provided it can be fitted without modification to the engine.

E. Engine and Drive Train

1. Any exhaust manifold or exhaust headers may be used.  Exhaust pipes and mufflers may be replaced with straight pipe(s).
2. Substitution of the clutch and flywheel is allowed provided there is no increase in clutch diameter.
3. Exhaust emission control air pumps and associated lines and nozzles cannot be modified in any way except that they may be completely remoed.  When these air nozzles are removed from a cylinder head, the holes must be completely plugged.
4. Class A (over 2-liter) cars are permitted to overbore without limitation except that the resultant displacement may not exceed 305 cu in.  Other cars may rebore a maximum of 1.2mm over the standard size, however, the resulting increase in engine displacement may not result in a total displacement exceeding the class limit for that car.
5. The cooling fan may be modified, substituted or removed.
6. Any piston may be used
7. Any camshaft(s) may be used.  The standard or recognized optional tappets (cam followers) must be used.
8. It is permitted to lighten, balance or modify in shape by tooling the standard or optional components of the engine and drive train provided it is always possible to identify them poritiely as such.  It is not permitted to add any material or mechnical extension.
9. Additional shiims required for valve adjustment or for maintaining the geometry of the valve train after machining operations are allowed.
10. The use of alternate engine and drive train components which are normally expendable and considered replacement parts, such as seals, bearings, valves, valve guides and valve seats, are allowed provided they are the same type and dimension.  Busings may be installed where none are fitted as standard.
11. The substitution of valve spring retainers and keepers is permitted
12. Any push rods may be used.
13. Generator, crankshaft, and water pump pulleys may be altered or replaced with others of unrestricted origin.  The use of any crankshaft vibration dampener is allowerd.
14. Compression ratio may be increased by machining, using a thinner gasket, or doing without one.
15. Any oil pan (sump) may be used.  The use of any oil pick up is allowed provided there is no modification required to the oil pump.
16. Any final drive ratio may be used except that no substitution of the gear housing is permitted.
17. The use of any limited slip differential, expect that no substitution of the differential housing is permitted.
18. Any transmission ratios may be sed in the standard or recognized optional transmission.   The number of forward and reverse gears may not be changed.
19. Any modifications may be made in the linkage between the clutch pedal and the cluth housing including the replacement of mechanical linkage with a hydraulic system.
20. A heavy duty propeller shaft (drive shaft) may be used in place of the standard shaft.
21. The installation of any vent or breather on the engine, transmission or differential and the use of oil catch tanks is permitted.
22. Any engine oil filter may be used.

F. Cooling System

1. The use of any engine, transmission, and differential oil cooler is permitted provided it (they) are mounted completely within or under the coachwork but not in the driver/passenger compartment.  Oil pump(s) may be added tot he transmission and differential for the oil cooler(s).  Air ducts may be fitted to the oil coolers(s) provided they do not etend more than 12 inches in any direction from the oil cooler fins.
2. The use of any water radiator is allowed provided the standard radiator mounts are retained and there are no changes in the body, chasis or internal structure of the car to accommodate its use.  Separate expansion or header tanks are permitted.
3. Sealing or shrouding the air flow area between the normal grille opening and the water radiator is permitted.
4. On water cooled cars, thermostats may be modified, removed or replaced with blanking sleeves or restrictors.

G. Fuel Induction System

1. The carburetor(s) provided by the manufacturer may be replaced by another (others) of a different size or make, provided the number of carburators and venturis be the same as provided by the manufacturer, and that they can be mounted on the intake manifold of the engine witout using any intermediary device, and by using the original attachment points

Any alteration to the standard fuel injection components except:

• Changing the location, type, or number of air throttles (butterfly, slice, etc) or changing the inside dimensions of the air duct at the air throttle.
• The addition of material to the intake manifold.
• Changing the number or location of the injection nozzles.
• Changing the make and model of the fuel metering and/or fuel distribution unit. The fuel metering and/or fuel distribution unit may be modified without restriction provided that it can be positively identified as that fitted as standard equipment.
• Any linkage may be used between the carburetor throttles and the accelerator pedal.

2. Any air filter may be used or the filter may be removed.  Dynamic air intakes may be fitted on the carburetors.
3. Any fuel pump(s) may be used and the location of the pump may be changed.  Fuel lines may be relocated except they may not pass through the drivers compartment.   Fuel lines of a different type or size may be used and they may be provided additional protection.

H. Brakes

1. The use of dual master cylinders and pressure equalizing devices is permitted.
2. Any brake lining may be used provided the dimension of the inner friction surface is not increased.
3. A servo-assist system may be used.
4. Backing plates or dirt shields may be ventilated and air ducts may be fitted provided no changes are made in the bodywork.  Dirt shields may be removed.
5. The handbrake in its entirety may be removed.
6. Any brake lines may be used, they may be relocated and may be given additional protection.

I. Safety Fuel Tanks

1. General
   

Fuel tanks in Production Category crs may be substituted with safety fuel tanks conforming to the SCCA safety fuel tank standards. Such safety fuel tanks must be produced by manufacturers specifically approved by the SCCA and shall be of the standard dimensions and capacities below:

22 Gallon	W 17"	L 33"	H 9"
15 Gallon	W 17"	L 24"	H 9"
8 Gallon	W 12"	L 20"	H 9"

Bladder type tanks shall utilize a container of 20 gauge steel (min.) -- add 1/4" to each dimension above for maximum outside dimension of the container.

2. Capacity
   

There shall be no restriction of fuel capacity when installing safety fuel tanks except for Trans Am Competition (see Appendix c) and the installation of more than one of the standard 22, 15 or 8 gallon fuel tanks is permitted.

3. Installation, Fittings, Lines

7.1 Definition

A formula for single-seat, open-wheel racing cars usein standard Ford Cortina 1600 GT "crossflow" engines and with firewall, floor, and safety equipment conforming to the GCR.

7.2 Engine

A. General

The engine shall be standard Ford Cortina 1600 GT "crossflow" and may not be altered, modified or changed in any respect unless specifically authorized herein.

Balancing and polishing is permitted within the following tolerances.   Dimensions and weights must be within these tolerances except where otherwise stated:

1. Fully non-machined surfaces: within 2.50%
2. Machined surfaces: within 0.15%
3. Weights of partly machined parts: within 1.00%
4. Weights of fully machined parts: within 0.75%

B. Block

• Bore: May be enlarged for clearance between cylinder and piston.
• Maximum compression ratio: 9.5:1
• Minimum combustion chamber volume per cyl: 47 cc
• Deck height at TDC: 0.025 in (min)

C. Cylinder Head

• Depth of combustion chamber: 0.12"
• Maximum width of combustion chamber measured from front to back at nearest possible point to deck: 3.15"
• Diameter of ports at manifold fact of head: inlet -- 1.37", exhaust 1.13"
• Head thickness measured from rocker box face to deck (0.020" tolerance): 3.20"
• Minimum cylinder head combustion chamber volume per cylinder: 7.8 cc
• Standard head gasket must be used -- part No. 2737E-6051-A

D. Intake Manifold

• Weight with studs (± 2.5%): 3.0 lb
• Outer ports: 1.45" x 1.25"
• Inner ports: 1.25"
• Carburator flange: 2.985" x 1.355"
• Machining of the carburator flange to the horizontal is permitted.

E. Pistons

The following pistons may be used:

• Standard Grades 0 through 7: Part No.: 2737E 6110-F or 2737E 6110-G
• First oversize (0.0025"): Part No.: 2737E 6110-A
• Second oversize (0.015"): Part No.: 2737E 6110-B
• Depth of bowl (±0.005"): 0.50"
• Maximum width of bowl: 2.28"
• Minimum volume of bowl: 31.50 cc
• Centerline of wrist pin to crown: 1.739" Max, 1.735" Min
• Overall height: 3.30"
• Weight with rigns and pin: 1 lb 5 oz
• Weight of pin (± 2 grams): 115 grams

F. Valves

• Distance apart at centers: 1.54"
• Maximum diameter: 1.50" Inlet, 1.25" Exhaust
• Overall length: 4.28" Inlet, 4.26" Exhaust
• Weight: 86 grams (3.034 oz) Inlet, 64 grams (2.257 oz) exhaust

G. Camsaft (Part No. 116E-6250A)

• Lobes, heel to toe: 1.31" Inlet, 1.312" Exhaust
• Base circle radius: 0.540" Inlet, 0.545" Exhaust
• Lift at spring cap: 0.341 Inlet, 0.337 Exhaust
• Lift at top of pushrod: 0.341 Inlet, 0.337 Exhaust
• Timing (tappet settings: 0.016" inlet, 0.026" exhaust) (± 4°)
  • Inlet: Opens at 27° BTDC
  • Inlet: Fully open at 109° ATDC
  • Inlet: Closes at 65° ABDC
  • Exhaust: Opens at 65° BBDC
  • Exhaust: Fully open at 109° BTDC
  • Exhaust: Closes at 27° ATDC

  Camshaft lobes may not be reprofiled.

H. Valve Springs

• Minimum diameter: 1.15"
• Mean diameter of wire: 0.152"
• Free length after use: 1.47"
• Diameter of cap: 1.07"
• Total number of coils: 6

I. Pushrods

• Minimum mean stem diameter: 0.25"
• Overall Length: 7.64"
• Weight: 50 grams (1.764 oz)

J. Connecting Rods

• Part Number: 2737E 6200-B
• Weight: 1 lb 7.25 oz

K. Crankshaft

• Part Number: 2737E 6303-A
• 23.88 lb
• Crankshaft pulley: free
• Stroke dimension: 1.526" - 1.530"

L. Flywheel

• Part Number: 2737E 6375-A
• Weight with ring gear and dowels: 18lb 12 oz (± 2%)

M. Carburetor

• Part Number: 2737E 9510B
• Venturi Diameter: Primary -- 26 mm, Secondary -- 27 mm

Permitted modifications:

1. The fitting of any jets.
2. Modification to provide for the simultaneous operation of both butterflys
3. The fitting of external anti-surge pipes
4. The removal of the air cleaner
5. The fitting of a velocity stack (intake air horn)

N. Exhaust Manifold: free

O. Lubrication System

• Oil sump and pump: free
• "Dry sump" is permitted

P. Cooling System

• Radiator, fan and water pump: free
• Tooth belt drive permitted

Q. Electrical System

• Generator/alternator: free
• Distributor: standard Autolite -- No. 12100
• Starter -- required: make/model free

A. General

7.3 Transmission

Any transmission may be used with not more than four forward gears and an operational reverse gear.

7.4 Final Drive

Any final drive unit may be used except:

1. Drive shall be to the rear wheels only
2. Limited slip and locked differentials are prohibited

7.5 Clutch

Free (including attachment to flywheel).

7.6 Fuel pump

Free

7.7 Chassis

The chassis shall be of tubular steel construction with no stress bearing panels except bulkhead and undertray.  The curvature of the undertray may not exceed 1 inch.  Tubes may transport liquid.  Monocoque construction is prohibited.

7.8 Suspension and Running Gear

All components shall be of steel with the exception of springs, hub adaptors, rear hub carriers, bearings and bushings.

Wheel spacers shall not exceed 1-1/2".

Any shock absorber may be used.

7.9 Body

1. No part of the frame or body shall project beyond a plane connecting the vertical centerlines of the front and rear tires.
2. The driver's seat must be capable of being entered without removal or manimupation of any part or panel
3. Wings (airfoils) are prohibited

7.10 Brakes

Free, except disc brakes are restricted to cast iron calipers.

7.11 Wheels

Wheels shall be 13" steel disc type with a maximum rim width of 5-1/2".  Wheels must be of standard manufacture, but the offset of the center disc may be altered.

7.12 Minimum Weight

881.6 lbs (400kg) -- including coolant and lubricants, not including fuel and driver.