STL + P2 + P at Buttonwillow Raceway Park

2024-05-01 P2 CN Spec ECU

#35835 from Bart Wolf · Rule change · TB 24-05 (2024-05 Fastrack)

In P2 Engine Table, Spec Line E, change the notes as follows:
"No engine modifications except for dry sump oil system, ECU mapping, and exhaust system the following: oil system, ECU, and
exhaust are unrestricted."

2024-05-01 P2 E&O - Correct FIA Group CN spec line notes

#35900 from Club Racing Board · Rule change · TB 24-05 (2024-05 Fastrack)

In P2 Table 1, FIA Group CN spec line, change the notes as follows:
"FIA Group CN homologated chassis, brake calipers and discs, hub carriers, and suspension components are required. V de
V European Proto Endurance Series Challenge permitted bodywork, rear diffuser, wing, wheels, and assisted
shifting are allowed. Car M must comply with all other P2 requirements. Competitors must have copies of FIA Group CN
Technical Regulations and V de V European Proto Endurance Series Challenge Sporting and Technical Regulations in their
possession and present them upon request are available here: https://www.scca.com/pages/technical-forms-and-downloads."

2024-12-01 STL Request to Remove Miata Hubs from General category

#37138 from Christopher Childs · Rule change · TB 24-12 (2024-12 Fastrack)

In GCR, Section 9.1.4.M.18., change as follows:
"18. Allow alternate front wheel front hubs, Mazda Motorsports Development Part #0000-04-5HUB-S1, for the 90-05 Mazda
Miata: Mazda Motorsports Development Part #0000-04-5HUB-S1."

2024-12-01 P2 2000 cc Pinto Engine Car Weight

#37187 from Marvin Hodges · Rule change · TB 24-12 (2024-12 Fastrack)

In P2 Engine Table, Line E Note 2, add the following:
"8. Minimum weight 1335 lbs."

2025-02-01 P Correct text in engine table notes

#37606 from Club Racing Board · Rule change · TB 25-02 (2025-02 Fastrack)

In Prototype Engine Table, Spec Line B, change the notes as follows:
"Staudacher cars may run 950 lb min. wt. minimum weight with 38.5mm flat plate intake restrictor."
In Prototype Engine Table, Spec Line D, change the notes as follows:
"No restrictor required at 1150 lb min. wt. minimum weight."

2025-02-01 P Update Prototype class designation

#37653 from Club Racing Board · Rule change · TB 25-02 (2025-02 Fastrack)

In Categories and Classes, GCR section 9.1, change as follows:
"9.1.8. SPORTS RACING CATEGORY CLASSES
A Sports Racing (ASR) Regional Class
Prototype 1 (P1)"
In Homologation Requirements, GCR section 9.2.2, change as follows:
"All Formula, Sports Racing, and P1, and P2 cars must be constructed in strict accordance with the rules and regulations
contained in the current GCR unless specifically excepted."
In Non-Metallic Wheel/Chassis Construction, GCR section 9.3.37, change as follows:

2025-05-01 STL E&O: SMX Allowance in STL

#37945 from Greg Amy · Rule change · TB 25-05 (2025-05 Fastrack)

In STL Spec Lines, Table B, Mazda Spec MX5 Challenge, change as follows:
Minimum Weight: "2500 See 9.1.7.1."
Notes: "Mazda MX5 Challenge car must utilize the following components: Roush CNC cylinder head 0000-01-5300,Mahle
standard or +0.005 0000-01-5310, OEM camshaft, 11:1 compression ratio, header 0000-06-5407-NC, exhaust 0000-06-5427-NC,
cold air intake 0000- 06-5150-KT, ECU flash 0000-01-5379, Pagid front brake pads 0000-03-5104-SP or endurance pads 0000-03-
5104-EN, Pagid rear brake pads 0000-03-5114-SP or endurance pads 0000-03-5114-EN, Penske front shock 0000-04-5291-SA,
Penske rear shock 0000-04-5292-SA, Penske rear mount kit 0000-04-5358, Front mount kit 0000-04-5359, Front offset bushing
0000-04-5407-NC, Eibach front springs 0000-04-9700-08, Eibach rear springs 0000-04-9400-07, Eibach helper springs 0000-04-

Applies to Mazda Miata on this page: Jared Korth, Ricardo Arruda, Gavin Wardle, Ryan Gutile, Bryce Johnson, Andy Chittum, Adrian Comstock

2025-05-01 P Add missing punctuation marks

#38150 from Club Racing Board · Rule change · TB 25-05 (2025-05 Fastrack)

In P Engine Table, Spec Line D notes, add the following:
"No restrictor required at 1150 lbs. minimum weight."
In P Engine Table, Spec Line G notes, add the following:
"Group CN non-composite chassis with Honda K20A-FD2 may use unrestricted individual throttle bodies at 1500 lbs. minimum
weight."
In P Table 1, Beasley B2 spec line notes, add the following:
"Engine must be Mazda 12A rotary with 40.5mm venturi. Car must comply with all other Prototype requirements."
In P Table 1, P2 cars built to 2000cc auto-based specification spec line notes, add the following:

2025-08-01 STL Lotus Weight Reduction

#38772 from Club Racing Board · Rule change · TB 25-08 (2025-08 Fastrack)

In 9.1.2. GT2/ST Spec Lines, Lotus Evora GT4, change Weight as follows:
"2750 2700"
In STU Table B: Alternate Vehicle and Engine Allowances, change Weight as follows:
Lotus Elise Cup R: "2300 2250"
Lotus Elise SC/ Lotus Exige SC: "2300 2550
2500 2450"

2025-08-01 P RM 25-05 - Prototype Engine Table A, 2 Cycle Restrictor Change

#38929 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)

Effective 8/1/25 in Prototype Engine Table, Spec Line A, change the restrictor as follows:
"40mm 38mm Restricted Venturi Size"

2025-09-01 P 13B Rotary Engine Rules Change Request

#38856 from Jason Vinkemulder · Rule change · TB 25-09 (2025-09 Fastrack)

Effective 9/1/25 in Prototype Engine Table, Spec Line K, change the restrictor as follows:
"40mm SIR with fuel injection or 41.5mm venturi with carburetor"

2025-09-01 P Add Radical Cup series Radical SR3 spec line to Table 1

#38916 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)

Effective 9/1/25 in Prototype Table 1 (Spec Line Cars), add the following:

2025-09-01 P Clarify spec line cars language

#38943 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)

Effective 9/1/25, in Prototype, GCR section 9.1.8.B.K, change as follows:
"P2 cars may compete in either the Prototype class or the P2 class but must participate in the Prototype class to the extent
necessary to qualify for an invitation to the Runoffs in Prototype. P2 cars may be modified to comply with the general Prototype
rules and Prototype Engine Table or may continue to run in P2 specification in the Prototype class as permitted in Table 1 below."
Table 1 (Spec Line Cars)

A specification table follows in the original; it is not shown here.

2026-01-01 P Request to Continue to Allow Carbon Brakes

#39476 from Jeffrey Lederman · Rule change · TB 26-01 (2026-01 Fastrack)

In Prototype, GCR section 9.1.8.B.F.2, change as follows:
"Brake calipers may be ferrous or aluminum alloy. Effective 1/1/2026, carbon-carbon and carbon-ceramic brake rotors are
prohibited and rotors must be ferrous. Brake rotor material is unrestricted."

2026-01-01 STL Weight adjustment for STL

#39579 from Super Touring Committee · Rule change · TB 26-01 (2026-01 Fastrack)

In GCR, Section 9.1.4.2.H.1. change Minimum Weight on chart as follows:

A specification table follows in the original; it is not shown here.