FF + FA + GT2 + SRF3 at Buttonwillow Raceway Park

2024-03-01 GT2 Classify Corvette C8 (2020- ) into GT2/ST

#33759 from Andrew Aquilante · Rule change · TB 24-03 (2024-03 Fastrack)

In GT2 Spec Lines, classify Chevrolet Corvette C8 (20-) as follows:
GT2-ST Maximum Displacement Minimum Weight Restrictor Notes
Chevrolet Corvette C8
(20-)
6162 3300 71mm -
Flat Plate
LT2 engine.

Applies to Chevrolet Corvette on this page: Igor Lyustin

2024-03-01 GT2 Requesting classification for a 2015 Mitjet ST in GT2

#35408 from Jim Froula · Rule change · TB 24-03 (2024-03 Fastrack)

In GT2 Spec Lines, GT Cars - MITJET ST, classify MITJET ST as follows:
GT Cars – MITJET ST
Model Years Body Style Drive-
line
Wheel-
base (in)
Notes
MITJET ST 2015 RWD 94.5 Must run per VTS specifications. Must have

2024-05-01 GT2 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"

2024-05-01 GT2 Request to Eliminate the FPR from the Corvette (-2013) with LS2

#35878 from Michael Quattlebaum · Rule change · TB 24-05 (2024-05 Fastrack)

In GT2-ST Spec Lines, Chevrolet Corvette (14-19), change Restrictor as follows:
"78 80mm flat plate"

2024-06-01 SRF3 SRF3 Alternator Pulley Update In

#36095 from Robey Clark · Rule change · TB 24-06 (2024-06 Fastrack)

SFR3, GCR section 9.1.8.D.2.H.17, change as follows:
"Alternator Pulley: P/N G902130, or P/N G902130A, or P/N G902131 (six row). 12 11 oz minimum weight."

2024-07-01 GT2 GT2-ST Rule Clarification

#36093 from Dominic Starkweather · Rule change · TB 24-07 (2024-07 Fastrack)

In GCR Section, Appendix K. 2012.M2, add the following:
"After market replacement differential housings are permitted as long as they are an exact equivalent."

2024-07-01 GT2 GT4 cars may run in GT2-ST

#36235 from Grand Touring Committee · Rule change · TB 24-07 (2024-07 Fastrack)

In 9.1.2. GT2 Spec Lines, GT3 Cars, change Note as follows:
"Note: All GT4 cars are permitted to compete in GT2-ST provided they use a factory supplied power stick or Pro Series
required restrictor. Must have GT4 rules in possession at all race events. Cars must comply with 2012 STO rules as
stated in Appendix K of the GCR. Engine Displacements in this table are nominal. Each competitor shall have available
definitive documentation (e.g., factory manual) of the original displacement for the engine used. Slicks allowed on all
GT2/ST cars with a 100-pound weight penalty."

2024-08-01 SRF3 Update Rain Tire Rule and Hoosier Decal Placement

#36436 from Robey Clark · Rule change · TB 24-08 (2024-08 Fastrack)

In SRF, GCR section 9.1.8.D.1.X.f, change as follows:
"Wet:
Front – Hoosier P/N 46100 P185/60R13 H20 or W2
Rear – Hoosier P/N 46105 P205/60R13 H20 or W2
Ground clearance is 2.5” with driver as raced when P185/60R13 (H20 or W2) tires are used.
OR
Front – Hoosier P/N 46101 P185/65R13 W2
Rear – Hoosier P/N 46105 P205/60R13 W2

2024-09-01 SRF3 Update to Letter 36619 with new Hoosier Contingency Decal Info

#36624 from Robey Clark · Rule change · TB 24-09 (2024-09 Fastrack)

In SRF, GCR section 9.1.8.D.1.X.f.3, change as follows:
"Four (4) "Hoosier" decals are required in the following locations: Two (2) 11" X 3" decals on the vertical plane of the front nose
to the outside of the cooling opening on each side and two (2) 18" X 5" decals, one on each side of the engine cover or above the
rear wheel openings on the vertical plane. Hoosier decals are available, free of charge, from all Hoosier tire distributors including
SCCA Enterprises Per Hoosier's contingency program, three (3) decals are required to qualify for contingency awards. One (1)
decal must be located on each side of the car and one (1) decal must be visible on the front."

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."

2024-10-01 SRF3 Update SRF3 Air Filter Rule

#36681 from Robey Clark · Rule change · TB 24-10 (2024-10 Fastrack)

In SRF, GCR section 9.1.8.D.2.H.23, change as follows:
"Air Filter: P/N WM301020 or K&N RC-9160"

2024-10-01 SRF3 Update SRF Brake Rotor Thickness

#36687 from Robey Clark · Rule change · TB 24-10 (2024-10 Fastrack)

In SRF, GCR section 9.1.8.D.1.X.g, change as follows:
"Brakes: Hawk Blue 9012 pads P/N 801993 must be used. Wilwood vented rotor P/N 800065 shall must be used as delivered with
no machining of any kind. Minimum thickness 12.20mm (0.481”) 13.25mm (0.522”)."

2024-10-01 SRF3 Hoosier Tire Decal Placement

#36739 from Robey Clark · Rule change · TB 24-10 (2024-10 Fastrack)

In SRF, GCR section 9.1.8.D.2.B, change as follows:
"Mandatory identification: "SRF3" near the side car numbers. "Hoosier" logo (4) on both sides front lower outer corners of the
nose and each side of the tail. Three (3) "Hoosier" logos, one (1) on each side of the car and one (1) on the center front of the car."

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 GT2 Panoz Esperante GTS BOP

#36686 from Brian Goldburg · Rule change · TB 25-01 (2025-01 Fastrack)

In GT2 SPEC LINES, GT Engines - PANOZ, classify 2013-2016 Ford EcoBoost Twin Turbo as follows:
GT Engines – PANOZ
Engine
Family
Engine Type Bore x
Stroke
(in.)
Disp.

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

2025-01-01 GT2 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.

2025-01-01 GT2 GT2 Sunbeam Tiger Alternate Carburetor

#37198 from Tom Patton · Rule change · TB 25-01 (2025-01 Fastrack)

In GT2 Spec Lines, GT Engines - SUNBEAM, add to Fuel Induction as follows:
"Carburetors(s) Holly 650 cfm PN #80541-1 and PN #80541-2"

2025-02-01 GT2 GT2/ST - Remove Aftermarket/Racing ABS penalty

#36538 from Jorge A Nazario · Rule change · TB 25-02 (2025-02 Fastrack)

In GCR, Appendix K. 2012 STO Rules, O.9., change as follows:
"May run OEM ABS or convert to an aftermarket ABS controller with 100 50 lb. weight penalty."

2025-02-01 FA Classify FR European Championship car as spec line car in Table 2

#37658 from Club Racing Board · Rule change · TB 25-02 (2025-02 Fastrack)

In FA Table 2, add the following:
Table 2 (Spec Line Cars)
Car Engine
Wheel
Width (in)
± .060
Aero Transmission Weight Notes

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

2025-03-01 GT2 Hood Bulge allowed

#37000 from Gordon Leslie · Rule change · TB 25-03 (2025-03 Fastrack)

In GT2 Spec Lines, GT2 Cars - PONTIAC, Fiero, change as follows:
Drive-line: "FWD RWD"
Add to Notes: "Hood bulge permitted as requested for front engine relocation only."

2025-03-01 GT2 OEM Wing Adjustment

#37590 from Christopher Childs · Rule change · TB 25-03 (2025-03 Fastrack)

In GCR, Section APPENDIX L. 2013 TA2 TECHNICAL REGULATIONS, B.2.c., change as follows:
"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."
In GCR, Section APPENDIX K. 2012 STO GENERAL TECHNICAL REGULATIONS, D.4.b., add the following:
"Factory wings, and spoilers, and roof vortex generators are permitted, but must be removed if an approved aftermarket wing is
installed. OEM aerodynamic devices do not need to adhere to the height rule."

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 FA Update Formula Renault 2.0 spec line notes

#37853 from Club Racing Board · Rule change · TB 25-03 (2025-03 Fastrack)

In FA Table 2, Formula Renault 2.0 (10-17) spec line, change the notes as follows:
"Engine must remain sealed. Car must comply with year-specific Formula Renault 2.0 manual, technical regulations, and all
applicable bulletins found here:. Competitors must have copies of these materials in their possession and present them upon
request.
https://sites.google.com/a/renault-sport.com/formule-renault-2-0-en/bulletins-techniques/2017,
https://sites.google.com/a/renault-sport.com/formule-renault-2-0-en/manuel-d-utilisateur/2017.
The following exceptions apply: Tire choice is unrestricted. No part of the car may be altered from original Formula Renault 2.0
components, except for necessary repairs that do not affect performance."

2025-04-01 SRF3 Driver Safety & Comfort

#37966 from Robey Clark · Rule change · TB 25-04 (2025-04 Fastrack)

In SRF, GCR section 9.1.8.D.1.D, add the following:
"f. Driver Safety and Comfort modifications to seat and controls for drivers with disabilities may be made only by approval. These
modifications must be reported to SCCA Enterprises and noted in the car logbook. The modifications are approved only for the
noted driver with disabilities. If the car is used by or sold to another driver, it must be returned to the previous standard
configuration."

2025-04-01 SRF3 Update SADEV transmission specs

#37992 from Club Racing Board · Rule change · TB 25-04 (2025-04 Fastrack)

In SRF, GCR section 9.1.8.D.2.K, change as follows:
"OR
SADEV-SRF3 6-Speed Sequential (beginning from Oct. 4, 2021 onward):
1st 12-36 3.0000 : 1
2nd 15-31 2.0667 : 1
3rd 18-28 1.5556 : 1
4th 22-28 1.2727 : 1
5th 24-26 1.0833 : 1

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

2025-07-01 FA Ligier JS F3 Tire Choice

#38434 from Rocco Magni · Rule change · TB 25-07 (2025-07 Fastrack)

In FA Table 2, FR Americas Ligier JS F3 spec line, change the notes as follows:
"Engine must be sealed in compliance with FR Americas or prior F3 Americas requirements. Car must comply with FR Americas
rules, with the following exception: front tires may be Hoosier P/N 43363, size 240/580R13 in MS compound, and rear tires may
be Hoosier P/N 43368, size 300/590R13 in MS compound. Competitors must have current copies of Formula Regional Americas
Championship Sporting Regulations, Onroak Automotive Ligier JS F3 Information Manual, and HPD engine-related specifications
and instructions in their possession and present them upon request."

2025-08-01 GT2 Rear Deck Lid for Older Air-Cooled Porsche

#38506 from Justin Erion · Rule change · TB 25-08 (2025-08 Fastrack)

In GT2 Spec Lines, GT2 Cars-Porsche, 911 Coupe & Targa., add to Notes the following:
"Porsche 911-based race cars (911,963,994), the use of the 993 3.8 RSR rear deck lid/spoiler is permitted. Aftermarket
reproductions of the original Porsche Motorsports deck lid provided they faithfully replicate OEM dimensions and functionality,
are acceptable for use."

2025-09-01 SRF3 SRF Rule Updates

#38853 from Robey Clark · Rule change · TB 25-09 (2025-09 Fastrack)

Effective 9/1/25 in SRF, GCR section 9.1.8.D.1.V.ff, add the following:
"SRF3 Oil Cooler, P/N G480503 may be used as mounted per the GEN3 Assembly Manual. No fan permitted for SRF. HD Oil
Cooler kit P/N G1148500 may be used as mounted per the GEN3 Conversion Manual."
Effective 9/1/25 in SRF, GCR section 9.1.8.D.X.g, change as follows:
"Brakes: Hawk Blue 9012 pads P/N 801993 must be used. Wilwood vented rotor P/N 800065 must be used as delivered with no
machining of any kind. Minimum thickness 13.25mm (0.522”). The Renault Alliance solid front rotors may not be used. Rubber
caliper bushings may be replaced with bronze bushings P/N 1196185 or P/N 1196185. Original caliper pistons may be replaced
with vented caliper piston P/N 1196184; no other modification allowed. Wilwood caliper with bracket universal fit P/N 800038

2025-10-01 SRF3 Add HD Oil Cooler

#38979 from Robey Clark · Rule change · TB 25-10 (2025-10 Fastrack)

In SRF, GCR section 9.1.8.D.1.V.ff, change as follows:
"SRF3 Oil Cooler, P/N G480503 or HD Oil Cooler P/N G1148500 may be used as mounted per the GEN3 Assembly Manual. No fan
permitted for SRF. HD Oil Cooler kit P/N G1148500 may be used as mounted per the GEN3 Conversion Manual."

2025-11-01 FA Re-Consider USF Pro 2000 Car for Formula Atlantic Class

#38783 from Augie Pabst · Rule change · TB 25-09 (2025-09 Fastrack)

Effective 11/1/25 in FA Table 2, add the following:

2026-01-01 FA Alternate Intake Manifold for MZR

#38223 from Ove Olsson · Rule change · TB 26-01 (2026-01 Fastrack)

In FA, GCR section 9.1.1.2.d, modify as follows:
"9. Intake manifold must be unmodified Elan DP02-60-003 or Mazda Speed equivalent Elite USF2015AT, 1.882” maximum bore
diameter at throttle plates. Elan or Mazda Speed equivalent Elite intake manifold may be replaced with unmodified intake Noor
P/N 0088-8-00 with intake runners AT Power P/N 13624."
"10. Elan DP02-60-003 or Mazda Speed equivalent Elite USF2015AT intake manifold must use an A aluminum spacer must be
used between the intake manifold and cylinder head castings; minimum spacer length is 2.200”."

2026-01-01 GT2 Additional Body Options to Replace Older Stock Car Bodies

#39086 from Samuel Daniels · Rule change · TB 26-01 (2026-01 Fastrack)

In GCR, Section 4.8.4.2.1., add the following:
"Cars in the class must use 1997, through current year, commercially available stock car bodywork. The following make/model
bodies are allowed:
1. Cadillac CTS
2. Chevrolet Impala
3. Chevrolet Malibu
4. Chevrolet Monte Carlo
5. Chevrolet SS

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 FA Engine Compression Rule Change Request

#39302 from Reilly Harris · Rule change · TB 26-01 (2026-01 Fastrack)

In FA Table 2, Formula 1000 spec line, change the Engine as follows:
"Motorcycle-based 4-cycle up to 1000cc, maximum compression ratio 14.5:1;. o Otherwise, current FA engine rules apply."

2026-01-01 GT2 GT3 Turbo to GT2?

#39365 from Chris Edens · Rule change · TB 26-01 (2026-01 Fastrack)

In GT2 Spec Lines, Engines - MAZDA, classify Engine Family BP as follows:
GT2 Engines - MAZDA
Engine
Family
Engine Type Bore x Stroke
(mm)
Disp.
(CC)

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

2026-01-01 GT2 Tech Bulletins for GT2 and GT2-ST

#39537 from Grand Touring Committee · Rule change · TB 26-01 (2026-01 Fastrack)

In GT2 Spec Lines, GT2 Cars – Porsche, classify 992.1 GT3 Cup as follows:
GT2 Cars – Porsche
Model Year Body
Style Driveline Wheel Base Notes
992.1
GT3 Cup
(22-25) 2 Dr RWD 4.0L flat six. 3250lbs. w/60mm Throttle Body Restrictor (TBR).
Cars must be prepared in accordance with the appropriate

2026-01-01 FA Change Formula 1000 allowances

#39608 from Club Racing Board · Rule change · TB 26-01 (2026-01 Fastrack)

In FA Table 2, Formula 1000 spec line, change the Notes as follows:
"Car must comply with December 2019 GCR Formula 1000 (FB) Preparation Rules, https://www.scca.com/downloads/48184-
gcr-december-2019/download, except as modified by this spec line. The prohibition of using carbon fiber in any external panels
or any panels licked by the airstream in Part 3.C of the December 2019 GCR F1000 (FB) Preparation Rules is removed, with the
exception that the car's floor pan/undertray must comply with the requirements of Part 2.D of the December 2019 GCR F1000
(FB) Preparation Rules. The prohibition of forward-facing gaps or openings in the bodywork in Part 3.I of the December 2019 GCR
F1000 (FB) Preparation Rules is removed. Part 3.D of the December 2019 GCR F1000 (FB) Preparation Rules is modified as
follows: "Between the rear of the front tire and the front of the rear tire, no point on the lower surface of the car (the surface

2026-02-01 GT2 Allow Larger Air Cooled Engines in Porsche 911 GT2

#39249 from Justin Erion · Rule change · TB 26-02 (2026-02 Fastrack)

In GT Spec Lines, create GT Cars - PORSCHE and classify SC as follows:
GT Cars - PORSCHE
Model Years Body Style Drive- line Wheel- base
(in)
Notes
SC 1978 2 Dr. Rear engine/RWD 89.45 May use alternate engine bore.
4.0L 2V @2275 lbs. 4.0L 4V @ 2350 lbs.

2026-02-01 GT2 Classify T1 BMW in GT2

#39408 from Jared Lendrum · Rule change · TB 26-02 (2026-02 Fastrack)

In GT Spec Lines, classify M3 E92 in GT Cars - BMW as follows:
GT Cars - BMW
Model Years Body Style Drive-
line
Wheel-
base (in)
Notes
M3 E92 (08-13) 2 Dr. RWD 108.7 Cannot be built to any other rule set.

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

2026-02-01 FA Pro Mazda Classification and Performance Enhancement Proposal

#39411 from Stephen Lamana · Rule change · TB 26-02 (2026-02 Fastrack)

In FA Table 2, Pro Formula Mazda spec line, change the notes as follows:
"All current FA rules apply to areas not covered by this spec line. Apex seals unrestricted. Street port or bridge port
allowed. Unmodified OEM l Lower intake manifold required unrestricted, upper intake manifold unrestricted. Balance tube not
permitted. Fuel injection only. Maximum 70 80mm T throttle B body. The maximum height of the wing and/or
endplates shall must not exceed 99cm (38.98 inches). The overall maximum width of the bodywork behind the front
wheels shall must not exceed 132cm (51.97 inches)."