Conduct that is unsafe or inconsistent with the spirit and purpose of the Autocross Program will not be permitted. The Potomac Region PCA Officers, Board of Directors and the Autocross Chair reserve the right to suspend driving privileges or refuse entry to any participant who fails to abide by the rules stated herein or otherwise implied.

Any driver disqualified more than twice for reasons of misconduct will be prohibited from participating for the remainder of the series.

Event points will be awarded to the top finishers within each class, minus one car (i.e. two cars in a three car class will win points). All other participants will receive 1 point for participation. Drivers who do not work at the event forfeit their points for that event.

Points are awarded as follows:

Autocross Season Class Awards shall be awarded to Potomac PCA members at the end of the season as follows:

• Scoring is to be based on a driver's total accumulation of points earned in a single class (transfers are not permitted) in the number of events that are counted. Scoring will be based on counting a driver's best finishes according to the following schedule:

• A driver must compete in at least 50% of the season's events in one class to become a Ranked Driver (3 of 6, 4 of 7, 4 of 8).
• Ranked Drivers qualify for a season award within their class.
• The Guest Class participants are not considered ranked drivers.
• Ranked Drivers competing in more than one class during the season cannot combine points from the different classes.
• Number of awards per class:

Model Classification Tables are at Appendix A.

Competitors are responsible for the policing of and adherence to the car classification rules. The Autocross and Tech Chair shall handle all Classification and Modification protests. All decisions are final.

Class Bumping

One participant makes a class. There is no class bumping.

So is your Porsche Showroom Stock, Production, Improved or Modified?

Compare your Porsche against the Category Allowances chart at Appendix B:

• If your Porsche is listed in a Showroom Stock class but fails to conform to each item in the Stock column, then it bumps to the corresponding Production class.
• If your Porsche fails to conform to each item in the Production column, then it bumps to the Improved class.
• If your Porsche fails to conform to each item in the Improved column, then it bumps to the Modified class.

Class Summary Descriptions

There are four categories of classes for Porsche automobiles – Showroom Stock (S), Production (P), Improved (I) and Modified (M). Each category is then broken down into classes based on the specific automobile for Showroom Stock and Production classes and based on number of cylinders and displacement for Improved and Modified classes.  Based on historical attendance numbers, there is currently only one class for Modified and one class for Improved.  Stock has six classes, and Production has five classes.   

Showroom Stock (S) - As the name implies, the Showroom Stock (S) Category is for automobiles nearly identical to those as they were available from the dealer.  Very few changes are allowed and tires must have a tread wear rating of 140 or greater (no R Compound tires).  Aftermarket wheels are allowed, but they must have the same width and diameter as available from the factory.  Neither supplemental driver restraints nor aftermarket seats are allowed.

Production (P) - The Production (P) category is for automobiles that have limited performance modifications.  Aftermarket seats, supplemental driver restraints, roll bars, and steering wheels are allowed, but the rest of the interior must remain intact.  Aftermarket coil springs/torsion bars are allowed, but they must be the same type and mount in the same manner as original.  DOT approved R Compound tires are allowed.

Improved (I) - The Improved (I) category is for automobiles with more substantial performance-affecting changes from standard (stock) specification. These modifications have defined limits.

Modified (M) - The Modified (M) category contains automobiles that have performance-affecting modifications outside of the limits of the Improved category and for race automobiles (factory-built or otherwise).

Guest (G) - The Guest category is for non-Porsche automobiles.

If you are unsure about the your vehicle class, please check with the autocross staff for guidance.

Protests

All classification and modification protests must be presented in writing to the Autocross Chair within 20 minutes of the last run. The decision of the Chair is final. The decision need not be made at the event.

General

The addition of safety equipment such as roll bars, roll cages, fire extinguisher, safety harnesses, harness guide bars, etc., is permitted and recommended.

• Roll bars are recommended for cabriolets.
• No drugs or alcoholic beverages are permitted at the event.
• Passengers are generally not allowed. See the policies page for details.
• An adult must accompany children at all times.
• Dogs must be leashed, where permitted.

COVID Procedures

- First and foremost, all participants must follow CDC and local (either VA or WV, depending on the site) guidelines.

- If you feel sick within the 14 days prior to the day of the event, you must stay home! A full refund will be issued.

- You must bring a mask with you and wear it at all times that you are out of you car. If you do not have a mask, you must leave the site and a full refund will be issued.
- When using the on-site porta-potty, you must leave your mask on so that we don’t not provide a vector for the virus to spread through the air in an enclosed space. 
- Social Distancing must be followed at all times. Please keep 6ft or more in between yourself and others. 
- Summit Point requires that you remain in your paddock spot when not working or driving. 
- For those of you working the course, please bring your own work gloves. 
- Please bring your own hand sanitizer.

- With the exception of preauthorized student/instructor pairings, no passengers are allowed in cars. 
- No spectators or guests allowed. 
- No walkup registrations.
- No minors are allowed on-site. The JPP has been temporarily suspended. 
- No breakfast will be included (lunch is still provided).
- No loaner helmets will be provided. You must have your own Snell 2010 newer SA or M helmet. If you do not have a valid helmet, please purchase or rent one or cancel your registration and a full refund will be issued. 
- Raffle and class win stickers have been suspended.

Tires

Cord may not be visible before, during or after official timed runs. Recapped or regrooved tires are not allowed. Street tires (Stock classes) must have visible tread across the entire tread surface.

Helmets

All drivers and instructors must wear helmets. Helmets must be Snell 2010 or newer SA (Special Applications) or M (Motorcycle). SA rating is recommended. DOT helmets are not permitted. Face shield is required if vehicle is not equipped with a full windshield.

Pay special attention to fit. The helmet should not be so tight that it brings on a headache, but your head should not rattle within it either. The goal is to have a helmet that is snug enough to prevent your head from having a distance to travel before hitting the padding.

Due to the ongoing COVID pandemic, at this time we have suspended our loaner helmet program. OG Racing is a fantastic local supplier with a wide selection of helmets for any budget, and for anyone who might be just wanting to test the waters of autocross before buying a helmet OG also has a helmet rental program where the rental cost can later be applied towards the purchase of a helmet. Please call OG Racing for details on this program as it is not listed on their website.

Clothing

Open toed shoes, sandals and bare feet are not permitted. Rubber soled shoes (sneakers, etc.) are recommended. Driving shoes and gloves, as well as fire resistant clothing, are recommended but not required.

Seat belts

All cars must have metal-to-metal seat belts, securely anchored, or harnesses. All drivers and any permitted passengers must wear belts or harnesses.

Windows

The driver's side window shall remain fully down during a run. Passenger windows may be fully up or fully down, if no passenger is in the vehicle. When a passenger is in the vehicle, the passenger's side window must be fully down during a run.

Cleaning out your car, glove box and trunk

Loose objects inside the trunk, passenger compartment and glove box must be removed from the car. Loose objects include cell phones, change, paper, garbage, cups, floor mats, etc. In other words, everything must be removed from your car.

The spare tire need not be removed if it is securely fastened. The battery must be securely fastened as well.

Pit & Paddock Area

All cars are to be parked within the designated pit & paddock area, except for vehicles used by timing, safety, and the Autocross Committee.

There is no speeding in the pit & paddock area. Any driver speeding in the pit or paddock area may be disqualified from the event at the discretion of the Autocross Chair or Committee. Please, no speeding in the general vicinity of the event.

Tire warming is not permitted.

Inclement Weather

An event may be postponed, delayed or cancelled due to inclement weather at the discretion of the Potomac PCA Officers, Board, Autocross Chair or Committee. If an underway event is terminated early, placing and points will be awarded on best time for the lowest number of runs completed by all entrants within class.

Waiver of Liability

Driver/Spectator Insurance Waiver. Each entrant and spectator must sign the event waiver form. Please see the policies page for requirements for junior participants.

Entrants

A participant may enter and compete in only one car per event.

Instructors

Instructors will be available near the start. If you want an instructor, please notify the grid worker. The Autocross Committee will ensure you have an instructor when you want one.

Work Assignments

Mandatory work assignments are allotted to each driver. If you are unsure of your work assignment, please ask. You must complete your work assignments to run. If you do not complete your work assignments, you will be disqualified (i.e., your runs will not count and no points will be awarded. You also will be disqualified from entering the next autocross event.

Timing, Radios and Flagging

Each flagging station will have a radio and a red flag. A fire extinguisher will be located at Timing. Chairs, cameras and other distractions (to the course workers and drivers) are not permitted at flagging stations for safety reasons. Do not stand with your back to any car on the course.

It is the responsibility of the flaggers to maintain safe conditions on the course, as well as the location and status of the cones for the purposes of scoring. We cannot have a good event without precise flagging. Please pay attention and be accurate with your calls.

All communications shall be addressed through Timing. No cross communication between flagging stations. Please speak slowly and clearly into the radio. If a car hits a cone, please notify Timing as follows: "Timing, this is station 3, one cone, car 43." Timing will acknowledge the call. If you do not know the car number, describe the car (e.g., "black 914").

The red flag indicates an emergency or an unsafe condition. If there is a dangerous situation on the course or you are if directed by timing or the course marshal to use the red flag, the red flag should be waved immediately. Do not put yourself in harm's way when waving the red flag at a car. Any driver who continues to run the course at speed, after the red flag has been waived, will be disqualified from the event.

Car Numbers

Each car shall have its official number clearly marked on both sides of the car. The car number on the registration form will determine the official number of the car for that event. The numbers shall be approximately 10-12 inches tall, clearly visible, and legible. Two-driver cars require a different number for each driver.

Course Map

A course map shall indicate entrance and exit area, the general course layout and course boundaries. The map is not drawn to scale.

Walking the Course

It is strongly recommended that all drivers familiarize themselves with the course by walking it prior to the drivers meeting. No wheeled or motorized devices are permitted on the course, including bicycles, roller blades, skateboards, "go-peds" and the like.

Cones, Pylons and Penalties

Each autocross event is run on a unique course laid out by cones and is designed with the safety of course workers, participants and their cars in mind.

Each cone and gate must be properly executed to avoid penalty points. Each downed or standing out-of-the-box pylon (cone) shall count as a two-second penalty. All chalked cones count, including those before and after the timing equipment. Helper cones are not subject to penalty. If you hit a standing cone in a gate, you cannot be declared off course at that gate.

Official Runs

The Autocross Chair and Committee will determine the official number of timed runs for an event. The quantity of runs will vary depending upon number of cars, length, difficulty and complexity of the course, weather conditions, etc.

Each run taken will count towards the total number of runs for the day. Runs not taken within your assigned run group will not be scored; they will be entered as DNF (did not finish), but will count towards the total number of runs for the day. Please take your runs with your run group unless you are directed otherwise by timing.

Runs taken with an instructor will be scored.

All cone penalties for each run and its associated re-runs will be recorded.

If a driver observes a problem with the course (e.g., a cone out of its box, a cone missing, etc.) or if a driver was not at fault in hitting a cone (e.g., swerved to avoid collision with something/someone on the course), the driver should come to a safe, immediate and complete stop and indicate the problem to the course worker so as not to be charged with the penalty. Follow the instructions of the course worker/timing. You may be instructed to exit the course via the finish or to return directly to grid. 

Re-runs

Re-runs may be granted by timing for a variety of reasons, including but not limited to a timing malfunction, unsafe condition, misplaced cone, etc. If the Red Flag is waved while running, immediately come to a safe and complete stop.

Re-runs should be taken as soon as practical, but no later than the end of the run group. 

Run Groups

The cars are generally split into two or three run groups; each group will have up to 30 cars. The run group shall determine your work assignment or driving time.

All drivers are to follow the directions of the grid workers. All attempts should be made to follow the grid. No car should start its next numerical run before the entire run group has completed its run.

Off Course/DNF

An off course or DNF will be entered as a score if a gate/cone is missed or if all four wheels (and the car) leave the course. A spin on course does not constitute a DNF if no gates have been missed and the car has not left the course boundaries.

DNS

A DNS (did not start) will be entered for any run not started. A driver may elect not to take all of the runs for the day.

Penalties

Each downed or standing out-of-the-box pylon (cone) shall count as a two second penalty. All chalked cones count. Helper and pointer cones are not subject to penalty. If you hit a cone in a gate, you cannot be declared off course at that gate.

Finish Line/Stop Box Penalty

The hitting of any cones at and after the finish timing equipment, whether or not a stop box is used, constitutes a DNF.

Timing

The timing device will be automatically started and stopped by the competing vehicle. All recorded times will be considered official unless protested. In the event of a timing problem, the competing car will be waived off course (red flagged) and given a re-run.

Official Times

Times will be recorded per the timing equipment and will be considered as official time. Penalties for cones will be noted on the timing slip (if used) and will be added to the official time for a total score. The official results will be posted to the Autocross section of the Potomac web site. If there are issues with your times, please contact the Autocross Chair.

Protests

All protests must be presented in writing to the Autocross Chair within 20 minutes of the last run. The decision of the Chair is final. The decision need not be made at the event.

Pre-runs, fun runs and exhibition runs

In order to verify course safety, flow and clarity, the Course Designer or other designee of the Autocross Chair shall pre-run the course prior to the commencement of walk-throughs. The pre-run shall be made with a passenger whose duties are to assist in the verification and to adjust pylon placement as required. 

Exhibition or fun runs will not be permitted until the official completion of an event and will be permitted only at the discretion of the Autocross Chair.

The Autocross Chair and/or Autocross Committee reserve the right to charge an additional fee per run for fun runs.

IF YOU ARE UNSURE OF ANY RULE OR PROCEDURE, DO NOT HESITATE TO ASK THE AUTOCROSS CHAIR FOR EXPLANATION OR CLARIFICATION.

Find your Porsche model and generation in these charts to determine your Showroom Stock or Production class.  Only one class exists in Improved and Modified classes. See Appendix B for category allowances.

PCA Potomac generally follows the autocross competition rules as published in the current Porsche Club of America Parade Competition Rules.  

Classes
There are four categories of classes – Showroom Stock, Production, Improved and Modified. Categories are related to automobile configuration. Based on historical attendance trends, PCA Potomac follows the guidelines regarding the number of classifications based on “medium” sized regions for Stock classes, and “small” sized regions for Production, Improved, and Modified classes.

The Showroom Stock (S) Category contains classes of automobiles as normally delivered and specified for use in the United States and Canada. Factory options as normally available for a specific model year are permitted. Certain factory and/or dealer installed equipment/ options will move an automobile out of S and into Production or higher as specified in the Modifications Allowed List.

The Production (P) category contains automobiles (as normally delivered to the United States and Canadian public through authorized sales outlets of the manufacturer) manufacturer) with allowances for limited performance-affecting changes from stock.

The Improved (I) category contains automobiles with more substantial performance-affecting changes from standard (stock) specification, whether changed by the factory, dealer or owner. These modifications have defined limits. These automobiles are classed according to their number of cylinders and actual displacement.

The Modified (M) category contains automobiles that have performance-affecting modifications outside of the limits of the Improved category and for race automobiles (factory-built or otherwise). These automobiles are classed according to their specified number of cylinders and actual displacement.

Currently, the classes are as follows:

 The following table is adapted from the 2007 Porsche Parade Competition Rules (PCR), Appendix V Autocross Modifications Allowed List, to be generally consistent with the 2007 SCCA Solo II definitions of authorized modifications for Stock and Street Prepared classes (SCCA 2007 Solo Rules Sections 13 and 15).

• If your Porsche is listed in a Stock class but fails to conform to each item in the Stock column, then it bumps to its corresponding Street Prepared class.
• If your Porsche fails to conform to each item in the Street Prepared column, then it bumps to the Improved class.
• If your Porsche fails to conform to each item in the Improved column, then it bumps to the Modified class.

Chart Abbreviations:

• NCA = No Change Allowed. The listed item must be as was available from the manufacturer as a standard feature or factory option in the United States or Canada for the automobile's model and year. For Stock, even wear & tear items (excluding tires) must be comparable in construction and specification to the originally supplied factory components.
• F = Free. Modification, substitution, elimination is allowed without effect on classification.

PCA Potomac generally follows Porsche Club of America Competition Rules in defining modification allowances, with the exception of specified additional allowances for the Showroom Stock category included at A-2.5.4. Allowances are divided up into five categories: Free, Showroom Stock, Production, Improved and Modified.

IF PCA POTOMAC AUTOCROSS RULES DO NOT SPECIFICALLY PERMIT A MODIFICATION, IT IS NOT ALLOWED EXCEPT IN MODIFIED.

NEW for 2022 Season: Please review Sections A-2.5.4.a,b,e and A-2.5.5.3.a for updates.

Appendix 1 provides a summary of allowed modifications.

A-2.5.3. “Free” Modifications. Safety equipment is free in all classes except Showroom Stock, provided limits of any class category are met. Items considered free include harness bars, fire extinguishers, non-factory seat belts, race seats, window nets, head rests, cut-off switches, tow hooks, seat back braces and required mounts for any of the above. In Showroom Stock, attachments points or mounts for any of these items may be left in the automobile, but the actual device will not be allowed to remain or be used if it could be considered to provide the driver or the automobile any performance advantage.

A-2.5.4. Showroom Stock Modifications. Unless otherwise specified in these rules, no alterations or modifications are allowed to these automobiles.

1. Any type wheel may be used provided it is: the same width as standard; the diameter is within +/-1” from a standard wheel for the car, and as installed it does not have an offset more than +- 7.00mm (+-.275”) from a standard wheel for the car. The resultant change in track dimensions and tire sizes are allowed, and tire widths may deviate from stock provided they safely fit on wheels that meet the criteria of the class’s restrictions.  Wheel spacers are permitted provided the resultant combination complies with the offset requirements of this section.  Wheel studs, lug nuts, valve stems (including pressure-relief types) and/or bolt length may be changed.  Tire pressure monitoring sensors may be removed.
2. All Showroom Stock class tires must be Department of Transportation (DOT) approved and have a tread wear rating of 180 or greater.
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.
4. Spare tire, tools, and jack may be removed
5. Gear Shift Linkages: Alternate shift knobs or paddles are allowed, as well as Porsche factory short-shift kits.
6. Data acquisition systems (including video cameras) and the accompanying sensors are allowed but may serve no other purpose during a run than real-time display and data recording.
7. The engine air filter element may be replaced provided the air flow path remains as originally designed (i.e., no additional openings). No other components of the air induction system may be removed, replaced, or modified.
8. Adjustments are permitted provided no modifications and/or alterations are necessary to achieve the desired adjustment.

No other aftermarket equipment that might be reasonably perceived as performance affecting is permitted in these classes. Items included in this restriction include, but may not be limited to, aftermarket exhaust systems, aerodynamic aids, computer chips, five/six point seatbelts, race seats, harness bars, roll bars, roll cages, etc.

A-2.5.5. Production Modifications. The Production category is for street automobiles altered beyond the Showroom Stock limits and older Porsches. The following adjustments, alterations or modifications are allowed in the Production class automobiles plus what was allowed in Showroom Stock. Automobiles may be updated to another model provided all of the automobile is brought up to that models specifications.

A-2.5.5.1. Engine

1. Air Cleaner: The air cleaner may be removed or replaced with another type.
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 may be used except for those chips programmed to alter turbo boost. No modifications to the intake manifold are allowed.
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 may be lightened.
15. Velocity Stack: Velocity stacks may be added or modified.
16. Compression Ratio: Engine compression ratio’s 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.

A-2.5.5.2. 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. Shocks Absorbers: Any shock absorber may be used provided it is not remotely adjustable. (any Porsche system such as PASM that was allowable for the specific model is permitted).
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.
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.

A-2.5.5.3. Brake/Wheel/Tire

1. Tires: All tires must be Department of Transportation (DOT) approved. Any DOT listed tire may be used providing they have a visible tread, have DOT wear indicators and have visible tread across the entire tread surface. These may be “R” type (less than 180 tread wear) tires. 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: PCA Potomac moved allowances to Stock.
4. Increased Rim Width: Rim width may be increased up to 1.0” over the widest rim available from the factory (front and rear respectively; see Appendix V) 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: PCA Potomac moved allowances to Stock

A-2.5.5.4.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: 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.
5. Air Dams: Any front air dam, unless as delivered as a factory option, is permitted provided it does not extend to less than 3” above the ground and not forward of the front bumper.
6. Seam Reinforcement (914 Only): Seam reinforcement kits are permitted "free" on 9l4s, 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. Weight: Automobile must meet minimum weight. Ballast is not allowed.
9. Bolt-on windshields: Bolt-on windshields may be removed.
10. Jack/Tools/Manuals: PCA Potomac moved allowances to stock

A-2.5.5.5. Transmission

1. Limited Slip: Limited slip is permitted in all automobiles
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.

A-2.5.6. Improved Modifications. The improved category is for street vehicles with modifications beyond those allowed in the Production Category. The modifications are limited but much more liberal than those in the Showroom Stock or Production Categories. The following adjustments, alterations, or modifications are allowed in the Improved class automobiles plus what was allowed in the Showroom Stock and Production classes.

A-2.5.6.1. Engine

1. Mufflers: Mufflers may be removed provided this is permitted by the event organizer and the local authorities/jurisdiction.
2. Ignition: Any ignition system is allowed.
3. Gasoline: Any gasoline is permitted.
4. Engine Substitution: Any Porsche engine is permitted in any automobile.
5. Fuel Management: Automobiles may use any fuel management/induction system including chips or other means that alter turbo boost. Turbochargers or superchargers are permitted.
6. Compression Ratio: Engine compression ratio’s may be increased up to 1.0 points.
7. Battery Location: The battery may be located anywhere within the automobile.
8. Intake System: Any intake system may be used.
9. Wet/Dry Sumps: Any change or addition is permitted.
10. Camshafts: Any camshaft may be used.

A-2.5.6.2. Suspension

1. Shock Absorbers: Multi-adjustable or remotely adjustable shock absorbers are permitted.
2. Camber Plates: Camber plates are permitted. Machining of factory mounting points is permitted to allow greater suspension adjustment.
3. Raised Spindle: Raised spindles are permitted on strut type suspensions.
4. Suspension Mounts: Any suspension mount may be used provided the number of mounting points and mounting locations remain as factory.
5. Suspension Arms: Any suspension arm may be used provided use requires no other automobile modifications. For example, this includes the use of any lower control arm, tie-rod assembly and/or bump steer kit.

A-2.5.6.3. Wheel/Brake/Tire

1. Brakes: Any brake modifications are permitted. Any brake biasing valve is permitted.
2. Tires: Any DOT tire is permitted. The cord may not be visible before, during or after official timed runs.
3. Track Width: Modifications to track width are permitted up to 2.0” over stock. Only 356 models with drum and very early disc brakes may use individual spacers for each wheel stud.
4. Increased Rim Width: Rim width may be increased up to 2” over widest rim available from the factory (front and rear respectively; see Appendix V) for that model range so long as the width does not extend beyond the fender.
5. Wheels: Wheels may be any diameter.

A-2.5.6.4. Chassis/Body/Interior

1. Roll Bars/Roll Cages: Roll bars or full interior cages are permitted.
2. Spoilers: Any spoiler is permitted.
3. Air Dams: Any front air dam is permitted.
4. Interior: Automobile must have dashboard, windows (glass or Plexiglas), visors (if originally equipped), headliner, and door panels. The original number of seats and passenger restraints must be present. Removal of mats and loose carpeting is allowed (i.e., what isn’t originally screwed and/or glued down). Headlights, taillights, brake lights and turn signal lights must be operational.
5. Bodywork: The use of fiberglass or other material body components is permitted for the following components: hoods (front and rear), rear deck lids, bumpers and rocker panels.
6. Fenders: Fenders may be altered to allow fitting of alternative wheels and tires.
7. Fuel Tanks: Fuel tanks may be changed and/or relocated.

A-2.5.6.5. Transmission

1. Transmission: Any Porsche based transmission is permitted.
2. Transaxle gear ratios. Any ratio set may be used outside of the specified gear set. Ring and pinion may be altered.
3. Limited Slip: Any limited slip may be used.

A-2.5.7. Modified Modifications. The modified category includes all automobiles modified beyond the allowable limits specified in the Showroom Stock, Production and Improved categories as well as some Limited Production and “tuner” automobiles. These rules provide the minimum that is required for the automobile to compete in this category. Some items are specified that are not allowed in this category. Unless defined as a production vehicle with complete documentation proving so, all racing, rally and special non-production Porsche models shall be included in this category.

A-2.5.7.1. Engine

1. Engine: A Porsche based engine is required.
2. Displacement: The displacement may be increased to that of the maximum in the class.
3. Fuel Management: Modifications to the fuel injection or carburetion system are free. The use of turbochargers or superchargers other than those used in production is permitted by class allowance. Modified boost pressure is permitted.
4. Ignition: Any ignition system is permitted.
5. Nitrous Oxide Systems: These systems are not permitted.

A-2.5.7.2. Suspension

1. Machined Suspension: Any adjustment may be made and machining is allowed (such as machining to attain negative front camber on 356-series cars). Suspension points may be relocated.
2. Multi-linked Suspension: This suspension type is permitted and is free.

A-2.5.7.3.Wheels/Brake/Tire

1. Wheel and Tire: Any wheel and tire combination is permitted. Non-DOT tires are permitted. The cord may not be visible before, during or after official timed runs.

A-2.5.7.4. Chassis/Body/Interior

1. Chassis: Original Porsche based chassis, unibody or tube frame chassis is permitted.
2. Roll Cage: Any roll cage may be used. It may be used to connect suspension or any other component.
3. Bodywork: Automobile bodywork must maintain recognizable external features of the Porsche model. All four tires shall not extend beyond the fender openings at the highest point of the tire, unless the Porsche model was originally an open-wheeled design. Automobile bodywork must include a front and rear trunk or deck lid and doors.

A-2.5.7.5. Transmission

1. Transmission: Any Porsche based transmission is required.

A-2.5.8. 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 by the Safety Inspection team or the Protest Committee at their discretion or by protest of a competitor in the same class the automobile is competing.