Proposed Rule Changes for 2025
August 7, 2024
PCA Club Racing Rules Committee
Racers: Here are the rules change proposals submitted by drivers and other interested parties for which the Rules Committee would like to receive comments. Listing does not indicate that the Committee favors any of these changes. These are just proposals for comment. From time to time comments received on proposals have helped us avoid mistakes, especially those based on an incorrect understanding of the performance factors involved, helped us word rules better, modify proposals, and given us more confidence that changes adopted are likely to be improvements overall.
The wording (or the concept) of the proposed changes is in italics. What follows for most proposals is an extremely brief statement of why the proponent felt the change would be beneficial. These may not be entirely accurate but should help the reader understand the reasoning put forth.
Comments may be submitted to rules@pcaclubracing.org through September 1, 2024. Please note that at this stage entirely new proposals for change are not appropriate. Those should be submitted between February 1 and June 1, 2025.
PDF copy of the proposed rule changes shown below can be downloaded using this link.
Current Rule Book
Download your copy of the current rule book — sans the proposed changes summarized here — for comparison purposes. You can also view and search an online copy of the current Rule Book.
QUICK LINKS
Use these links to jump directly to specific changes:
Stock Class General
Some Spec or other classes specifically allow minor modifications which are not expressly allowed in Stock, but which are often found on dedicated track cars when race prepared. Adding the following allowances to Stock will permit shortening some Spec class rules (at least any future ones), and clarify what is allowed in stock to reinforce the “if it isn’t allowed it is forbidden” approach in Stock. Most of these questions have arisen or at least been foreseen in one or more Spec classes:
- Emergency brake lever, cables, and associated parts may be removed.
- Clutch disk and pressure plate must be factory or aftermarket stock equivalent. This does not apply to rubber-centered disks or permitted replacement of dual mass flywheels, which are governed separately.
- If hood pins are installed, stock hood latches may be removed or disabled.
- The windshield wiper arms and blades may be removed.
- Electrical wiring for parts which may be removed may be removed.
- Seam sealer, undercoating, weather stripping, and tubing for water drainage may be removed.
- Plastic fender liners may be removed, or holes cut in them.
- Thermal insulation and shielding may be removed.
- The immobilizer box may be relocated inside the driver’s compartment.
- Fuse panels may be replaced and relocated.
F-Class Boxsters to Lose 20 Pounds
There are an active group of racers with these cars who have proposed a spec class. They dominate the class and are concerned that at their current stock weights, they burn through tires at an unsustainable rate and would like a 200 lb weight reduction. Mainly for this they have proposed a spec class. From a series administration perspective, this is not appealing – ME1 has had a slow start and required a lot of work to make it a true spec class, particularly in dealing with a spec shock. The PCA class system is fragmented enough as it is. One or both of the following alternatives could achieve part or all of the goals of these racers, although they would affect other cars listed in F or also other classes.
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- Give F-class cars a 100-pound weight reduction.
The previous general weight reduction stopped at G. This boundary was in a sense arbitrary, based on an assessment of who was racing in which of the lower classes. Giving it to all cars in the class would maintain the current balance of power within F.
- Give F-class cars a 100-pound weight reduction.
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- Make a 100-pound weight reduction a Prepared allowance.
Prepared cars have always had to carry the weight assigned to the model in Stock, with the Prepared allowances limited to various engine, transmission, bodywork, and aero modifications. While this would allow prepared cars of any class to run lighter and move F cars into G, it should help ameliorate the tire wear issue.
- Make a 100-pound weight reduction a Prepared allowance.
SP3 Non-Aero Weight Break
- Allow SP3s which do not have any of the following aero modifications to run 75 pounds lighter than what the weight chart lists: a wing or wings, dive planes/canards, aftermarket rocker panels, and modifications to the underside of the vehicle for the purpose of improving aerodynamics.
The proponent’s intent is to keep the classic look of these cars, and provide a competitive cost-effective entry point for new drivers to this class. The restrictions have been limited to those easily spotted. Rear wings provide a performance advantage that is not always available to other drivers, and also make the cars more GT class than stock. The addition of an effective rear wing often requires an engine that is capable of still performing under the added drag of large wings – it also adds to the overall cost of developing a competitive car. This sub-class should make for better racing, with aim at growing the class by making it more affordable.
SPC
- SPC transmissions – allow the 2008 non-S six speed.
This non-S transmission is the same as the S except for 2d gear, which is lower. This appears not to convey any advantage no matter the track, and changing it just adds cost to converting a non-S donor to SPC specs.
Dry Sump
GTB1 997.2 Intakes
- Disallow upgraded intakes for the 997.2 models.
When an allowance of the GT3 82mm throttle body and plenum was extended to GTB1 987.1 cars in an attempt to keep them competitive with the 987.2 models, the wording used extended this to “911s.” At the time this included 996s and the 997.1 models, but was not limited when the 997.2 models with DFI arrived. This was an oversight. A modified intake is not required for the 997.2 to be competitive, and no 997.2 seems to have changed its intake.
GTB1 997.2 Performance Balancing
- Increase the minimum weight of the 997.2 to 3200 lbs from 3100 lbs.
The proponents say this would create a power to weight ratio for a PDK 997.2 (which would be 3300 lbs. and the factory 991.2 Carrera horsepower of 345) of 9.56 lbs/hp on par with the 987.2 (9.53 using Porsche’s 320 hp figure for the S model) yet still better than the 981 (9.92 at 320 factory horsepower in GTB1). All recognize that the improved exhausts and flashes mean the cars as raced have higher horsepower.
They also cite an ability to use more Cup body parts on the 997 than the Cayman for improved aero and greater torque from a larger engine as performance advantages available to the 997.2 but not the Cayman which should be balanced with increased weight.
GTB1 and GTB3 981 PDK Weight
- Change the 981 PDK extra weight from 125 pounds to 100.
Experience suggests that the belief that the 981s had so much of a performance advantage over other Caymans that they needed a substantial handicap were shown by the GTB2 experience to be exaggerated. Using the same 100 extra pounds as a PDK balance for all GTB PDKs will simplify the rules.
GTC1
- Allow 1990-93 Euro Cups, and 1992 USA Cups any exhaust, any shock, and any suspension spring.
The original shocks and springs are no longer available. Experimentation with different exhausts has indicated that the limitations on intake and the relatively low max hp negate any small advantage that a different exhaust might make. More importantly, several other venues in which these rare cars can run do not have these limitations, so participation by these cars may increase with these changes.
GTC4 and 5
- Allow the use of ABS systems.
The addition of ABS is becoming very common in these cars as backup insurance to save the race car in the event of a driver error, sudden emergency ahead, or rain. Many racers have added ABS, so must run (if they run with PCA) in a GTA class, thus reducing competition in GTC. By now there are racers with no experience on the track without ABS until they acquire one of these Cups. Professional racers seldom use the ABS outside of emergencies or rain, so its performance advantage is limited. This proposal was very divisive in 2017, but racing demographics change.
- Allow Paddle shifters.
The addition of paddle shifters is said to double the transmission rebuild intervals over the manual sequential shifter because of its greater precision. The paddle system removes the driver’s input on pedals and shift lever from the shifting process. The cost of the system is said to be saved by the time of the first rebuild. Many racers have added paddle shifters to these models, so must run (if they run with PCA) in a GTA class.
A car moved to GTA2 would need a bigger motor and other expensive modifications to be competitive just because of one or both of these additions.
Championship Points Tie Breakers
- The proposal changes the tie breaker system in Appendix H, Section 6 to emphasize head to head results.
The current language for ties states:
Championship Totals:
The best 13 race point totals for each racer in all points scoring races for the year will count toward the National Championship. Ties for the first three positions will be broken by the highest total in the 14th race then 15th race etc. […]
The proposal would read:
Championship Totals: The best 13 race point totals for each racer in all points scoring races for the year will count toward the National Championship. Ties for the first three positions will be broken by the total head-to-head results for each racer. For example, if Racer 1 and Racer 2 compete in the same event(s) then whichever Racer placed ahead of the other most often wins the first tiebreaker. In the event that this result is also a tie (2-2 in head to head for example), then the result of the first head-to-head shall be the second tie breaker. In the event there are no head-to-head races, then ties for the first three positions will be broken by the highest total in the 14th race then 15th race etc. […]
