PCA members in good standing, of any class of membership set forth in the by-laws, and non-members by invitation of the NCR Autocross Chair, may register and compete in NCR Autocross events.  NCR members who wish to invite a guest should contact the autocross chair.  Non-members driving a Porsche and Renegade Miata Club members are automatically invited subject to all other requirements. Other non-members may register on a space available basis.

Competitors must be at least 18 years of age and have a valid driver's license. 16/17 year old drivers who are children of active PCA members may register with permission of the autocross chair. 16/17 year old drivers must hold a valid, unrestricted driver's license and otherwise comply with the requirements of the Junior Participation Program. Contact the autocross chair for more information.

Online registration is required prior to the event. Every registrant is required to check in with registration at the event. Every registrant must present a valid driver's license and sign the insurance waiver. PCA members may be asked to present their PCA membership card or pay the non-member rate. All automobiles must successfully pass a tech/safety inspection. See the Safety section below.

Entry fees are published on the NCR Autocross Registration Site.

Official registration will close as announced for each event. Late registration will be allowed only at the discretion of the Registrar and will be assessed a late registration fee.

There are five categories of NCR classes. Categories are related to automobile configuration.

• The NCR Porsche Street (PS) category contains stock Porsche automobiles with limited performance-affecting changes.
• The NCR Porsche Race (PR) category contains Porsche automobiles with more substantial performance-affecting changes.
• The NCR Non-Porsche Street (XS) category contains non-Porsche automobiles defined by the SCCA Street category.
• The NCR Non-Porsche Touring (XT) category contains non-Porsche automobiles defined by the SCCA Touring category.
• The NCR Non-Porsche Race (XR) category contains non-Porsche automobiles from the SCCA categories that permit race tires (Street Prepared, Street Modified, Prepared and Modified).

The term stock as used herein refers to automobiles, components or configurations that were readily available from Porsche as standard or optional equipment on automobiles intended for street use as normally delivered and specified for use in the United States and Canada. Note that this does not include European-spec or other region automobiles.

NCR classification is different than the PCR or neighboring region classes. Automobiles are grouped into base classes based on performance potential. Base classes are combined into larger Competition classes. A handicap system called PAX is utilized to adjust scores for each base class. There are six Porsche Street base classes and four Porsche Street Competition classes. Non-Porsche base classes are defined according to SCCA® National Solo®rules. The event chair may at his or her discretion reclassify an automobile to maintain competitive classes.

All Porsches qualified for NCR Street Category and/or SCCA Street Category are classified by the base classes from the following chart:

All Porsches that do not qualify for the NCR Porsche Street category will compete in the NCR Porsche Race class.  Porsche automobiles in the Porsche Race class are classified into base classes according to SCCA® National Solo® rules.

Non-Porsche automobiles are classified into base classes according to SCCA® National Solo® rules into base classes.

To keep a practical limit on the number of classes and foster competition, NCR groups base classes into larger classes according to the table below. To keep the competition fair within these combined classes, NCR uses a common handicap system called the PAX index. For more information see NCR PAX Information. Each base class is assigned a PAX factor based on this index. These factors facilitate comparing times of cars which are in different base classes. All NCR Competition class are scored by PAXed times. However, many of the competition classes in the Street category consist of a single base class

The Novice Classes are open to any eligible competitor who started autocrossing with any club less than one year prior to the event. Anyone who has previously won an NCR Novice class (or any NCR class) is no longer eligible.

The Porsche Champions Class is a Porsche only class restricted to previous NCR Class Champions. This includes Porsche and non-Porsche Class Champions if driving a Porsche. Current champions from last year are required to compete in this class if driving a Porsche.

The allowed modifications are mostly based on PCA Parade Competition Rules (PCR) for Production Category and include SCCA Street Category allowances. If not explicitly authorized herein, any modification allowed by the PCR Production rules or by SCCA Street rules is implicitly authorized by these rules.

IV.C.1.1. Engine

1. Air Cleaner: The air cleaner may be removed, modified or replaced with another type. Any modification may not conflict with other rules.
2. Modified Ignition: Any modification is permitted, provided an original type distributor is used.
3. Modified Carburetors: Any automobile originally carbureted may have any carburetor, provided the throttle bore and venturi dimensions are not changed from original specifications. Jet sizes may be changed. 911 models with mechanical fuel injection or Solex carburetors may change to replacement carburetors that have throttle bores no larger than 40mm. 914/912E models may be converted to carburetors with throttle bores no larger than 40mm.
4. Fuel Injection: No substitution of performance affecting components for fuel injected automobiles is permitted. Any DME EPROM chip or flash may be used except for those chips and flash programmed to alter turbo boost. No modifications to the intake manifold are allowed. Water-coooled car models built after 1996 may us any throttle body.
5. Wet Sump Modifications: If an automobile has a wet sump lubrication system, the sump may be modified to ensure a constant source of engine lubrication at the oil pickup tube. If an automobile has a dry sump lubrication system, no modifications are permitted.
6. Modified Oil Cooler/Filter: The addition of any oil cooler and/or filter is permitted.
7. Substituted Roller Bearing Cranks: For 356-based or Carrera 4-based engines, any roller bearing crank may be used. Plain bearing cranks may be substituted for roller bearing cranks. Counterbalanced cranks are permitted.
8. Balanced Engine: Balancing of internal engine parts is permitted.
9. Camshafts: The stock camshaft must be used.
10. Exhaust Modifications: Alternate exhaust systems are permitted after the head(s) for automobiles with or without catalytic converters. Headers are permitted. A muffler is required. Air pumps may be removed.
11. Air Conditioning: Removal is permitted provided original automobile may have been delivered without it.
12. Overbore: Overbore is allowed up to 1.2MM (0.047”).
13. Gasoline: Any grade of automotive gasoline available to the general public through normal retail service stations is permitted.
14. Clutch: Any model clutch is allowed. Rubber center clutch discs may be replaced with spring discs. The flywheel and pressure plate may be lightened.
15. Velocity Stack: Velocity stacks may be added or modified.
16. Compression Ratio: Engine compression ratio may be increased up to .5 points from U.S. production specifications.
17. Fuel Pump: Fitting of an electric fuel pump is permitted.
18. Chain Tensioners/Guards: Any chain tensioner or guards are permitted.
19. Battery: Any battery may be used. Those automobiles delivered with two batteries may remove one.

IV.C.1.2. Suspension

1. Limited Suspension Adjustments: Any adjustment of the standard suspension components is permitted, provided no machining is required for the adjustment. Factory components must be used for mounting of struts and shock absorbers to the body.
2. Alignment: Any adjustment may be made provided no other change is necessary to make the adjustment.
3. Coil Springs/Torsion Bars: Any coil spring may be replaced by any other coil spring. Any torsion bar may be replaced by any other torsion bar as long as they are of the same type and mount in the same manner without modification to the chassis or suspension components.
4. Shock Absorbers: Any shock absorber may be used provided it is not remotely adjustable. This does not permit addition of coil-over springs.
5. Adjustable spring perches are allowed.
6. Sway Bars: Any anti-sway bar may be installed. Sway bar may not be adjustable from the cockpit.
7. Rear Camber Compensation (356 only): Any rear camber compensating device may be used.
8. Bushings: Non-standard (non-elastic) suspension bushings may be used.
9. Shock Tower Brace: A front and/or rear shock tower brace may be used in any automobile provided that: (1) it can be quickly and easily removed, it must be a bolt-in component. Any number of attachment points may be used; (2) all attachment points are within three inches of a vertical plane passing through the top center of the shock absorber.
10. Spring Plates: Adjustable spring plates are permitted on any automobile not so equipped from the factory.
11. Tie-Rod Ends: The use of 911 Turbo tie-rod assemblies is permitted.</li
12. Hydro-pneumatic Suspension: Removal of this suspension is not only allowed but is encouraged.
13. A-Arms: 924/944/968 series may use aftermarket A-Arms provided suspension geometry is not altered.
14. Water-cooled (1996-on): Water cooled cars built after 1996 can use GT3 style lower control arms, any caster control arms, and any rear toe links.

IV.C.1.3. Brake/Wheel/Tire

1. Tires: All tires must be Department of Transportation (DOT) approved. Any DOT tire may be used providing they have a visible tread, have DOT wear indicators and have visible tread across the entire tread surface. Tires must have a minimum tread wear rating of 180 even if the vehicle came with race tires from the factory. Tire aspect ratio and width is free but must fit under the stock fender wells. Tires must be marketed nationally and generally available to all competitors. The cord may not be visible before, during, or after runs. Recapped tires or re-grooved tires are not allowed. Competitors are responsible for policing the “rubbing tire” rule and protests must be made before timed runs.
2. Track Width: Modifications to track width by the use of wheel spacers and/or wheel offset are permitted provided no modifications to the automobile, other than increasing the stud/bolt length, are performed. Increase may not be more than 1.0” over stock. Only 356 models with drum and very early disc brakes may use individual spacers for each wheel stud.
3. Brakes: Pads, linings, and brake lines of any manufacture may be used. Any type of brake cooling may be used. Rotors may be drilled or slotted. Brake bias valve may be changed but cockpit adjustable valves are not permitted. Cars with ceramic rotors may change them to stock dimension alternate materials rotors.
4. Increased Rim Width: Rim width may be increased up to 1.0” over the widest rim available from the factory for that model range so long as the width does not extend beyond the stock fender width as measured from the top of the tire and fits the stock fender wells.
5. Wheels: All wheels shall be the same diameter as available from the factory for the model range of the automobile or within an increase or decrease of 1.0” from the factory specifications.
6. Spare Tire: The supplied spare tire may be removed.
7. Cars using wheel bolts may change to studs as long as factory thread engagement is maintained.

IV.C.1.4. Chassis/Body/Interior

1. Limited Fender Modifications: Fenders (including wheel openings) may be modified provided the tire-wheel-spacer combination and ride-height setting used could be used without the fender modification (i.e., could be used on an unmodified automobile of the same model and year.) In the event of a protest, the entrant must be able to prove compliance with this rule.
2. Interior Modifications: Any accessory, gauge, or indicator may be fitted if its purpose is to improve driver or passenger comfort or convenience and provided such items have no effect whatsoever on mechanical performance. Alternate seats may be used and floor mats may be removed. Any steering wheel is allowed.
3. Roll Bars: Roll bars are permitted. Full interior roll cages are not permitted.
4. Spoilers and Wings: Any rear spoiler, unless as delivered as a factory option, is permitted provided the leading edge of the spoiler is attached to the automobile, the spoiler is no wider than the stock body width and the spoiler doesn’t exceed 5” in height from the leading edge. Any rear wing can be used as long as it is not wider than the door handles; does not extend past the rear of the car; no part is higher than the roof; and has less than six (6) square feet of area for all wing element (measured from directly above the car).
5. Air Dams and Splitters: Any front air dam, unless as delivered as a factory option, is permitted provided it does not extend to less than 2.5 inches above the ground and not more than 4 inches forward of the front bumper.
6. Seam Reinforcement (914 only): Seam reinforcement kits are permitted “free” on 914s, provided each reinforcement is limited to a single seam and that all reinforcements combined do not substantially increase the rigidity and stiffness of the chassis. It is recommended to 914 model owners to have the chassis inspected for rust on a periodic basis.
7. Bumpers: Bumpers may be removed on any 356 series automobile.
8. Bolt-on windshields: Bolt-on windshields may be removed.
9. Jack/Tools/Manuals: Removal of jack, tools and owner’s manual(s) is allowed.

IV.C.1.5. Transmission

1. Limited Slip: Any type of differential is permitted in all automobiles. Spools or welded differentials are not permitted.
2. Gear Shift Linkages: Gear shift linkages may be modified or exchanged. This permits the use of a short shift kit in any automobile or the use of side-shifter transmission in any 914.

Modifications allowed in the NCR Porsche Race Category are as allowed per SCCA® National Solo® Ruless.

1. Engine: A Porsche based engine that has a Porsche part number on the engine case or block is required.
2. Transmission: A Porsche based transmission is required.
3. Bodywork: Automobile bodywork must maintain recognizable external features of the Porsche model. Automobile bodywork must include a front and rear trunk or deck lid and doors.

IV.C.3. Other Modifications:

Any equipment, component, part, or modification which is deemed performance-affecting and which is not specified will make the automobile entered subject to reclassification to a higher class or category.