FF + GTX + GT3U + P at Buttonwillow Raceway Park

2024-05-01 GTX Request for Spec Line 1010 Reconsideration

#35009 from Kristofer Olson · Rule change · TB 24-05 (2024-05 Fastrack)

In GT2-ST Spec Lines, Acura NSX, change as follows:
Minimum Weight: "2700 3000"
Restrictor: "43 45mm TIR"

2024-10-01 FF Update to FF EGR Blanking Plate Rule

#36633 from Matt Boian · Rule change · TB 24-10 (2024-10 Fastrack)

In FF, GCR section 9.1.1.B.14.r.1, change as follows:
"All emission control devices must be removed and blocked off by the blanking plate provided by HPD or Fast Forward as noted
below, except for the VTEC activation valve. The VTEC activation valve must be retained; and it must be functioning. No
modifications are permitted.
a. EGR Plate: Fast Forward PN: FF200-301.
b. EGR Port Cover: Fast Forward PN: FF200-302."

2024-11-01 FF Change FF/FC Weight with Sequential Gearbox

#36651 from Robert Wright · Rule change · TB 24-11 (2024-11 Fastrack)

In FF, GCR section 9.1.1.B.20.A.3, change as follows:
"Cars running with a sequentially shifted gear box shall must add 25 10 lbs. to minimum weight."
In FC, GCR section 9.1.1.B.20.B.4, change as follows:
"Cars running with a sequentially shifted gear box shall must add 25 10 lbs. to minimum weight."

2024-11-01 FF Alternative Oversize Honda Fit Pistons

#37064 from Formula/Sports Racing Committee · Rule change · TB 24-11 (2024-11 Fastrack)

In FF, GCR section 9.1.1.B.14.e.1, change as follows:
"Honda Fit OEM standard size pistons, PN: 13010-RB1-000, or Honda Fit OEM 0.25mm oversize pistons, PN: 13020-RB7-Z00, or
Fast Forward 0.25mm oversize pistons, PN: FF800-110, may be used."
In GCR section 9.1.1.B.14.e.2, change as follows:
"a. Maximum standard piston diameter, measured at a point 16mm from the bottom of the skirt: 73.240mm
(2.8834 2.8835 inches).
b. Centerline of wrist pin to crown maximum: 26.21mm (1.032 inches).
c. Maximum overall height from skirt to crown edge: 47.80mm (1.882 inches).

2025-01-01 GTX Correct language regarding OEM Areo Devices

#37137 from Christopher Childs · Rule change · TB 25-01 (2025-01 Fastrack)

In GCR, Section APPENDIX L. 2013 TA2 TECHNICAL REGULATIONS, B.2.c., change as follows:
"B. Aerodynamic Devices
2. Rear wing
c. The entire rear wing assembly, including the end plates and any Gurney flap, shall be mounted level
with, or below, the peak of the roof. OEM aerodynamic devices do not need to adhere to the height rule."

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

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:

2025-03-01 FF Formula F Proposal to Invite Older Cars Via a Tire Rule Change

#37802 from Anthony Stefanelli · Rule change · TB 25-03 (2025-03 Fastrack)

In FF, GCR section 9.1.1.B.10.e, change as follows:
"Formula F shall be limited to the following tires (front tires may not be used as rears):
Dries:
Front - Hoosier R60A Radial 43322 or F1600 Radial 43321 185/60R13
Rear - Hoosier R60A Radial 43327 or F1600 Radial 43326 205/60R13
Wets:
Front - Hoosier Wet or W3 Radial 44421 185/60R13
Rear - Hoosier Wet or W3 Radial 44426 205/60R13

2025-03-01 GT3U Increase Minimum Weight

#37919 from Club Racing Board · Rule change · TB 25-03 (2025-03 Fastrack)

In STU Spec Lines, Table C: STU-GT3U, change Minimum Weight as follows:
"150 250 pounds"

2025-04-01 GT3U TCR Rulesets

#37981 from Club Racing Board · Rule change · TB 25-04 (2025-04 Fastrack)

In STU-GT3U Spec Lines, Table C, add the following:
"Table C: STU-GT3U
Refer to section 9.1.2."
In GCR, Section 9.1.4.H.7, change as follows:
"All current STU cars, except TCR cars, may reduce their weight by 4% after all other modifiers"

2025-05-01 GTX Request to Classify Porsche GT2 RS Clubsport

#37972 from Paul Fairchild · Rule change · TB 25-05 (2025-05 Fastrack)

In GTX, Classify Porsche GT2 RS Clubsport, as follows:
GTX
Make Homologation Model Restrictor
(mm)
Weight
(lbs) Notes
Porsche GT2 RS Clubsport Must have factory specifications available at all race events

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:

2025-05-01 FF Page 228, FF tire rule 9.1.1.10.e

#38251 from Anthony Stefanelli · Rule change · TB 25-05 (2025-05 Fastrack)

In FF, GCR section 9.1.1.B.10.e, change as follows:
"Formula F shall be limited to the following tires (front tires may not be used as rears):
Dries:
Front - Hoosier R60A Radial 43322 or F1600 Radial 43321 185/60R13
Rear - Hoosier R60A Radial 43327 or F1600 Radial 43326 205/60R13
Wets:
Front - Hoosier Wet or W3 Radial 44421 185/60R13
Rear - Hoosier Wet or W3 Radial 44426 205/60R13

2025-05-01 GT3U Table C: STU-GT3U Clarification

#38268 from Club Racing Board · Rule change · TB 25-05 (2025-05 Fastrack)

In STU Spec Line, Table C: STU-GT3U, change as follows:
Minimum Weight: “Current GT3 race weight plus 250 225 pounds”
Notes: "DOT approved tire with maximum section width of 245. GT3 cars base wheel is a maximum of 15”x9”. 18”x9” wheels
allowd with a 3% weight addition. GT3 cars utilizing 15”x7” wheels are limited to a maximum section width of 225 with a 25
pound weight reduction"
"All GT3U (Majors and Runoffs) cars using up to 15"x7" wheels limited to 225 section width tires shall run at current GT3 race
weight plus 225lbs. All Gt3U cars shall run a DOT approved tire with a maximum section width of 245. GT3U cars are allowed
optional 15"x9" wheels with a 1.5% weight addition or up to 18"x9" wheels with a 3.0% weight addition to the total weight

2025-06-01 GTX Ligier P3 LS Swap

#38164 from Bart Wolf · Rule change · TB 25-06 (2025-06 Fastrack)

In GTX Spec Lines, GTX-MISC., Ligier, LMP3, 3.0L, Add to Notes the following:
"Allow any normally aspirated LS Chevrolet engine may be used."

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 FF Formula F Alternative Tire Rule Proposed Clarifications

#39281 from Jay Messenger · Rule change · TB 26-01 (2026-01 Fastrack)

In FF, GCR section 9.1.1.B.10.e, change as follows:
"Alternatively, Formula F cars with rocker arm suspension (e.g., 1987-90 Reynard, Swift DB1,) and/or outboard suspension on at
least one chassis end homologated in 1989 or earlier with any combination of rocker arm or outboard suspension on all four
corners (e.g., 1987 – 1990 Reynard, Swift DB1) may use the following alternative tires. Note: This rule is intended to allow older
cars with the described suspension design to use the alternative tires. It is not to be exploited by modifying cars with push-rods or
pull-rods to meet the above requirements or by modifying either end of older cars to push- or pull-rod suspension to be eligible to
run the alternative tires. Cars that were homologated in 1989 or earlier with push- or pull-rod suspension on no more than two
corners may seek approval to run the alternative tire by utilizing the compliance process outlined in GCR section 8.1.4."

2026-01-01 GTX Please Consider Adding a Spec Line to GTX Table 4 for the RCR T70

#39470 from Peter Jankovskis · Rule change · TB 26-01 (2026-01 Fastrack)

In GTX-Misc. Table 4, classify RCR70 Coupe:
GTX – MISC. TABLE 4
Make Homologation Model Restrictor

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."