2023 Club Racing Rules – Effective Immediately

QUICK LINKS

Use these links to jump directly to specific changes:

• Prepared
• 911CUP – Eligible Models
• 911CUP – Brakes
• GTC – Exhausts
• Stock 991 & 992 – Control Arms
• SPC & SP996 – Tires
• Stock Boxster/Cayman – Rear Bumper
• SPB – Shock
• Enduro – Tools
• Safety Recommendation Rule
• GTD1 – Aftermarket Headers

Prepared

If a car whose base Stock class is F or below, and Prepared changes move the car to G or above, that car’s minimum weight is 100 pounds less than it base class weight.

911CUP

Eligible Models

Rule Change: The 911 models eligible for 911CUP, other than those built to SP911 specifications, are 1978-1983 US and ROW standard SCs, and 1984-1989 US Carrera 3.2s, along with the 1973 Carrera RS and 1990-1994 964 C2s and RSAs. Other existing track prepared 911 models listed in classes D through F Stock, including cars moved up to one of those classes due to Prepared modifications other than those allowed in 911CUP, may be considered on a case-by-case basis by the Rules Committee, with weight adjustment appropriate to the modifications.

Rationale: This change is necessary because when this class was first formulated as a balance of performance class, no attention was paid to the effect of unusual models (especially clones) or Prepared modifications on performance in the base D, E, and F classes. The case-by-case exception’s intent is to prevent adding (or creating new clones of) unusual models, or new Prepared cars for 911CUP, but to accommodate existing race cars. Balancing performance is more art than science, and the less it is a factor the better for this class.

Brakes

Stock-based 911CUPs may use any brake caliper and any non-floating brake rotor. Cars running stock 930 Turbo brakes may run the Turbo stock floating rotors.

GTC

Exhausts

GTC 5, 6, 7, and 8 may run the full (no muffling) or partial (no side pre-mufflers) Supercup exhausts.

Stock 991 & 992 Front Lower Control Arms

a) 991s are added to the list of Stock models allowed GT3 or aftermarket front lower control arms.
b) Stock 992s may run aftermarket front lower control arms.

SPC & SP996 – Tires

Due to supply issues with the Hankook Z214 C51 compound spec dry tires, Hoosier DOT R7s (245/35R18 front and 285/30R18 rear) are allowed as an alternate tire in SPC and SP996 until January 1, 2024.

Stock Boxster/Cayman – Rear Bumper Cover Venting

Boxsters and Caymans in Stock or Prepared may make the rear bumper cover venting and bumper alterations allowed in SPC Rule 6.2) (cut out license plate area, replace bumper with a less obstructive steel piece).

SPB – Shock

SPB Rule 4.E. is amended in part to read: Only the following shocks are allowed: Stock Porsche shocks for the model. Bilstein PSS9 shocks, part #F4-GM5-8847-H0 or #48-181440 with stock valving. Motion Control Suspension SPB, P/N SET-1WNR-SPB-01, or the superseding parts STR-1WNR-00067 (front) and STR-1WNR-00068 (rear). Minor trimming of rain gutter sheet metal in the rear trunk above the shock adjuster to improve access is allowed. Shocks cannot be cockpit adjustable.

Enduro – Rule 6

Enduro rule 6, which prohibits battery-operated tools in the pits, is amended to allow use of brushless battery-operated tools, including refueling pumps.

Safety Recommendation

A Safety Recommendation Rule from 2019 was accidentally omitted from the printed rule books.

It reads:

“Starting with the 981 and 991 models, Porsche has used a cast aluminum front shock tower. Excessive loading of the front suspension can cause the aluminum to fracture. These and subsequent models with the aluminum front shock towers in a Stock or Improved class may make the following modification: Install the Porsche front strut plate reinforcements right 991-504-284-8A and left 981-504-283-8A, successor Porsche parts, or an aftermarket equivalent such as the SP Motorsports strut tower support bracket kit, together with such fasteners and spacers as needed. These plates bolt onto the top of the shock tower and connect to the shock tower in two additional places.”

GTD1 – Aftermarket Headers

Because of premature failures of the factory headers, the following rule was adopted: “GTD1 cars may run aftermarket headers, with or without catalytic converters, which bolt onto the factory stock tailpipes.”

While the obvious intent was to replace only the header/CAT assembly affected by the failures, “tailpipe” proved to be an infelicitous choice of words for the rest of the exhaust system. Those who inquired were advised not to fabricate additional piping.

So the rule is reworded to read:

“GTD1 cars may run aftermarket headers, with or without catalytic converters, from where they bolt onto the exhaust ports to the connection with the rest of the factory exhaust system at the end of the stock catalytic converter’s location.”