P + AS + STU + FV at Buttonwillow Raceway Park

2023-03-01 STU E&O STU NA Weight Chart.

#33737 from Eric Heinrich · Rule change · TB 23-03 (2023-03 Fastrack)

Summary

As printed in Fastrack

In STU, GCR Section 9.1.4.1.H.1. chart, Factory Engine Displacement (cc) Minimum Weight (lbs), change as follows:
"2450 2596 2595"
"2600 2860 2710"

2023-04-01 STU Alternate OEM Miata Intake Manifold

#33827 from Brandon Steinhauer · Rule change · TB 23-04 (2023-04 Fastrack)

Summary

As printed in Fastrack

In STU Spec lines, classify Mazda BP5A as follows:
STU Maximum Displacement (cc's) Minimum Weight Notes
Mazda BP5A 1839 Chart May use engine in its entirety or specific
components from the engine.

2023-07-01 STU 2022 Toyota GR Cup for STU

#34449 from Club Racing Board · Rule change · TB 23-06 (2023-05 Fastrack)

Summary

As printed in Fastrack

In STU Spec Lines, Toyota GR Cup (2022-), classify as follows:

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

2023-08-01 AS Crate Motor Part Numbers

#32944 from Sam Daniels · Rule change · TB 23-08 (2023-08 Fastrack)

Summary

As printed in Fastrack

In AS, GCR Section 9.1.6.F.2., change as follows:
"GM Performance parts CT400 P/N-1937 → 0604 or 1937 → 0604 engine assembly for GM produced vehicles."

2023-08-01 AS Request wheel size change

#33007 from Michael Kamalian · Rule change · TB 23-08 (2023-08 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, Ford Mustang GT 5.0l (15-17) Restricted Preparation, change Notes as follows:
"Max. Wheel Size: Dia.18.0 19.0 inches."

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2023-08-01 AS Alternative Upper Front Control Arms for Dodge Challenger

#33352 from Clark Cambern · Rule change · TB 23-08 (2023-08 Fastrack)

Summary

As printed in Fastrack

In AS SPEC Lines, Dodge Challenger (08-20) Restricted Preparation 5.7L, 6.1L, or 6.4L V8 (Iron block, Aluminum heads), 2
valves/cylinder, change Notes as follows:
"SPC-66045 Alternate front upper control arms are permitted."

2023-08-01 AS Front Brake Caliper Adapters for Dodge Challenger

#33353 from Clark Cambern · Rule change · TB 23-08 (2023-08 Fastrack)

Summary

As printed in Fastrack

In AS SPEC Lines, Dodge Challenger (08-20) Restricted Preparation 5.7L, 6.1L, or 6.4L V8 (Iron block, Aluminum heads), 2
valves/cylinder, change Notes as follows:
"Stock brakes or alternate Dodge brakes (Part numbers: front caliper (0517 → 5106 (R) and 0517 → 5107 (L); rear caliper (R1542564 (R)
and R1542565 (L))) may be used with the brake rotor sizes listed in this specification line. Alternate brackets may be used to
facilitate updated/backdated components."

2023-12-01 FV FV Wheel Bearing Clarification

#35150 from Formula/Sports Racing Committee · Rule change · TB 23-12 (2023-12 Fastrack)

Summary

As printed in Fastrack

In FV, GCR section 9.1.1.C.10.G, change as follows:
"Front W wheel bearings"

2024-02-01 STU ST Electric-Assisted Steering Systems

#35066 from Jose Osiris Pena · Rule change · TB 24-02 (2024-01 Fastrack)

Summary

As printed in Fastrack

In GCR, Section 9.1.4.M.16., change as follows:
"Power steering may be modified in any of the following ways:
a. disconnected , pump, belt, pulley, and hoses may be removed. Hoses may also be looped. Steering rack or box may be
modified internally to work without pump.
b. an OEM manual steering rack for that model may be fitted
c. an electric power steering pump may be fitted
d. an OEM electric-assisted steering system may be used or any column mounted electric steering assist may be used
e. an OEM hydraulic-assisted steering system may be used"

2024-03-01 AS Request to Classify 1970-1981 Camaro and Firebird in AS

#33659 from Brandon Vivian · Rule change · TB 24-03 (2024-03 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, classify Chevrolet Camaro, Pontiac Firebird (70-81) Full Prep as follows:
AS Wheelbase Gear Ratios
Std. (or Alt.)
Brakes
(Max)
(in/mm)
Weight (lbs) Notes:

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

2024-03-01 AS Fuel Cell 12

#34194 from Clark Cambern · Rule change · TB 24-03 (2024-03 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, add to Notes as follows:
Cadillac CTS-V (04-07): “Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is taken
from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a safety fuel cell.”
Chevrolet/Pontiac Camaro & Firebird (93-02): “Fuel cells must be located within 24 inches of the standard tank. The 24 inch
measurement is taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with
installation of a safety fuel cell.”
Chevrolet/Pontiac Camaro & Firebird (93-02): “Fuel cells must be located within 24 inches of the standard tank. The 24
inch measurement is taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with

2024-03-01 AS Please Classify the 6th Gen Into AS.

#35448 from Daniel Richardson · Rule change · TB 24-03 (2024-03 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, classify Chevrolet Camaro (16-) Full Prep as follows:
AS
Wheelbase Gear Ratios
Std. (or Alt.)
Brakes
(Max)
(in/mm)
Weight (lbs) Notes:

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

2024-03-01 STU Letter #35397 addendum

#35453 from Aaron Fitzsimmons · Rule change · TB 24-03 (2024-03 Fastrack)

Summary

As printed in Fastrack

In STU Spec Lines, Mini Cooper S SC with Minimum Weight 1900 and 2100, add to Notes:
"Alternate LEAP OMICRON hood scoop part # LEP-OMICRON3 is permitted."

2024-03-01 STU S54 Drysump

#35464 from Macey Urso · Rule change · TB 24-03 (2024-03 Fastrack)

Summary

As printed in Fastrack

In STU Spec Lines, BMW S54 B32 OEM, add to Notes as follows:
"Dry Sump oiling system permitted."

2024-03-01 AS spec lines

#35713 from American Sedan Committee · Rule change · TB 24-03 (2024-03 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, classify Ford Mustang GT (05-14) with Restricted prep Engine as follows:
AS
Wheelbase Gear Ratios Std.

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

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2024-04-01 AS Restricted Prep Aftermarket Parts Request

#35682 from Tom Aquilante · Rule change · TB 24-04 (2024-04 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, Chevrolet/Pontiac Camaro & Firebird (93-02), add to Notes the following:
"For the LS1connecting rods Callies p/n CSC6100DS6A2AH, Scat rods p/n 2-1CR6100-944, GM performance rods p/n 12649190."
In AS Spec Lines, Pontiac GTO (04-06), add to Notes the following:
"For the LS1connecting rods Callies p/n CSC6100DS6A2AH, Scat rods p/n 2-1CR6100-944, GM performance rods p/n 12649190."

2024-04-01 AS Allowance of 11

#35824 from American Sedan Committee · Rule change · TB 24-04 (2024-04 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, Cadillac CTS-V (04-07), add to Notes the following:
"11" wide wheels can be used until 3/1/25."
In AS Spec Lines, Chevrolet Camaro SS (V8) (10-15), add to Notes the following:
"11" wide wheels can be used until 3/1/25."
In AS Spec Lines, Dodge Challenger (08-20), add to Notes the following:
"11" wide wheels can be used until 3/1/25."
In AS Spec Lines, Ford Mustang GT 5.0l (15-17), add to Notes the following:
"11" wide wheels can be used until 3/1/25."

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2024-05-01 AS 6th gen Camaro limited prep

#35733 from American Sedan Committee · Rule change · TB 24-05 (2024-05 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, classify Chevrolet Camaro 1LE (2016-) as follows:
AS Wheelbase Gear Ratios Std. (or Alt.)
Brakes
(Max)
(in/mm)
Weight (lbs.) Notes:
Chevrolet
Camaro, 1LE

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

2024-05-01 AS Chevrolet/Pontiac Camaro & Firebird (82-92) 5.7L V8 LS1 Alum BLK

#35825 from Desi Colon · Rule change · TB 24-05 (2024-05 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, classify Chevrolet/Pontiac Camaro & Firebird (82-92) 5.7L V-8 LS1 (Aluminum Block, Aluminum Heads) 2 valves
per cylinder, as follows:
AS Wheelbase Gear Ratios Std.

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

2024-05-01 AS Full Prep Head

#35891 from American Sedan Committee · Rule change · TB 24-05 (2024-05 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, Chevrolet/Pontiac Camaro & Firebird (82-92), add to Notes the following:
"Flo Tek Head part #102-500 are permitted."
In AS Spec Lines, Chevrolet/Pontiac Camaro & Firebird (93-02), add to Notes the following:
"Flo Tek Head part #102-500 are permitted."
In AS Spec Lines, Chevrolet Camaro (10-15), add to Notes the following:
"Flo Tek Head part #102-500 are permitted."
In AS Spec Lines, Ford Mustang Incl. Cobra & Cobra R (79-93) and Mercury Capri (79-86), add to Notes the following:
"Flo Tek Part # 203-500 are permitted."

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2024-06-01 AS Request for Classification of 2018-2023 mustang In

#35764 from Michael Kamalian · Rule change · TB 24-06 (2024-06 Fastrack)

Summary

As printed in Fastrack

AS Spec Lines, classify Ford Mustang GT 5.0L (2018-) as follows:
AS Wheelbase Gear Ratios

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

2024-08-01 STU RWD Turbo Disadvantage

#36255 from David Fiorelli · Rule change · TB 24-08 (2024-08 Fastrack)

Summary

As printed in Fastrack

In GCR, Section 9.1.4.1.H.3 - Inlet Restrictor (mm) Minimum Weight (lbs) table, change as follows:
"RWD cars must reduce restrictor 1 mm from this table"

2024-09-01 AS Mustang transmission ratios

#36662 from American Sedan Committee · Rule change · TB 24-09 (2024-09 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, Ford Mustang GT (05-14) with Restricted Prep Engine, add to Notes as follows:
"Alternate transmission Ratios 3.66, 2.43, 1.69, 1.32, 1.00, .68.”
In AS Spec Lines, Ford Mustang GT 5.0L (2018-), add to Notes as follows:
"Alternate transmission Ratios 3.24, 2.10, 1.42, 1.00, 0.81, .062."

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2024-10-01 FV Disc Brakes

#36822 from Guy Bellingham · Rule change · TB 24-10 (2024-10 Fastrack)

Summary

As printed in Fastrack

In FV, GCR section 9.1.1.C.4.D, change as follows:
"Any ferrous alloy, unvented rotor may be used, but must have a maximum diameter of 11.75 in. and a minimum thickness of
0.20 in. The otherwise smooth rotor may not be cross-drilled and may have a maximum of three pad cleaning grooves per side."

2024-11-01 STU R53 15% Pulley Request

#36980 from Aaron Fitzsimmons · Rule change · TB 24-11 (2024-11 Fastrack)

Summary

As printed in Fastrack

In STU Spec Lines, Mini Cooper S SC, add to notes:
1900: "Stock supercharger pulley. 2.565 diameter."
2100: "JCW Pulley permitted. May run a 2.285 diameter pulley."

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

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

Summary

As printed in 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 STU BMW N54/N55 Engine Allowance

#37146 from Martin Sarukhanyan · Rule change · TB 24-12 (2024-12 Fastrack)

Summary

As printed in Fastrack

"Turbo inlet restrictors designed per GCR Appendix F Technical Glossary definition of “Turbo Inlet Restrictor” may be required;
see table 9.1.4.1.H.h.2 3. Swapping of turbochargers between engine makes and models is prohibited. Supercharged cars may be
approved on a case-by-case basis; twin turbo engines are allowed on a case-by-case basis only. Contact the Road Racing
Technical Office for details. Twin turbo engines may be converted to single turbo using one of the allowed alternate turbos (see
9.1.4.1.H.3 2). Aftermarket turbocharger and supercharger kits will be allowed on a case-by-case basis.

2025-01-01 AS Increase Coyote Engine Restrictor to 80mm

#36177 from Gregory Eaton · Rule change · TB 25-01 (2025-01 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, add to Notes as follows:
Ford mustang (GT 05-14): "Gen 1- 67mm Gen 2-64mm"
Ford mustang (GT 05-14): "Gen 1- 67mm"
Ford mustang (GT 15-17): "Gen 1- 67mm"
Ford mustang (GT 94-04): "Gen 1- 67mm Gen 2-64mm"
Ford mustang cobra & Cobra R Mercury Capri (79-93) (79-86): "Gen 1- 67mm Gen 2-64mm"

2025-01-01 STU Audi 1.8t Wagon STU Table B

#36685 from Mike McLaughlin · Rule change · TB 25-01 (2025-01 Fastrack)

Summary

As printed in Fastrack

In STU Spec Lines, Table B: Alternate Vehicle and Engine Requirements, delete Audi/VW 1.8 Turbo in its entirety.
In STU Spec Lines, Table B: Alternate Vehicle and Engine Requirements, Porsche 944 w/Max Displacement 1800, change as
follows:
Weight: "3050 Chart"
Notes: "VW/Audi 1.8L 35mm turbo engine permittedinlet restrictor required."

2025-01-01 AS Performance Pack for 2015+ Mustang

#36867 from Michael Kamalian · Rule change · TB 25-01 (2025-01 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, Ford Mustang Coupe GT (05-14) Restricted Prep., change Notes as follows:
"The 4.6L engine assembly has a weight reduction of 300 lbs. 5.0L/6spd engine/trans: track pack front and rear spoiler allowed."
In AS Spec Lines, Ford Mustang Coupe GT (05-14) with Restricted Prep. engine, change Notes as follows:
"Max. Wheel Size: Dia.18.0 inches. Stock brakes or alternate Ford 14” Brembo Brake (Ford Racing Kit #M-2300-S) and full prep
brake package may be used. Either engine may be used. 1st Generation 5.0l Coyote 11-14 62mm FPR 2nd Generation 5.0l
Coyote 15-17 61mm FPR Cold Air Intake allowed Charge Motion Control Valves can be blocked off and removed for firewall
clearance Allow Cold Air Intake Tremec Magnum transmission may be used P/N- TUKT16901. Full Prep Transmissions rule
package may also be used. Max compression ratio, 11.2:1 track pack front and rear spoiler allowed. Alternate transmission

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2025-01-01 AS Gear Ratios

#37131 from Timothy White · Rule change · TB 25-01 (2025-01 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, change Gear Ratios as follows:
Cadillac CTS-V (04-07):
"2.97, 2.07, 1.43,1.00, 0.84,0.56 or 3.01, 2.07, 1.43, 1.0, .84, .57 or 2.20, 1.64,1.28,1.00 or 2.88, 1.91, 1.33, 1.00"
Chevrolet Camaro, Pontiac Firebird (70-81), Full Prep:
"3.42, 2.28, 1.45, 1.00 or 2.95, 1.94, 1.34, 1.00, 0.73 or 3.35, 1.93, 1.29, 1.00, 0.61, or 2.20, 1.64,1.28,1.00 or 2.87,1.89,1.28,1.00"
Chevrolet Camaro, Pontiac Firebird (70-81), Restricted Prep.:
"3.42, 2.28, 1.45, 1.00 or 2.95, 1.94, 1.34, 1.00, 0.73 or 3.35, 1.93, 1.29, 1.00, 0.61, or 2.20, 1.64,1.28,1.00 or 2.87,1.89,1.28,1.00"
Chevrolet/Pontiac Camaro & Firebird (82-92) Full Prep:

2025-01-01 AS ECU specs for LS engine

#37208 from Gary Mathews · Rule change · TB 25-01 (2025-01 Fastrack)

Summary

As printed in Fastrack

In AS SPEC LINES, Cadillac CTS-V (04-07) Restricted Prep., change Notes as follows:
"Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is taken from the perimeter of the
stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a safety fuel cell. Tremec TR6060
Transmission with 3.0 1, 2.07, 1.43, 1.0, .84, .57 ratios permitted. 11” wide wheels can be used until 3/1/25. Any ECM may be
used."
In AS SPEC LINES, Chevrolet Camaro, Pontiac Firebird (70-81) Restricted Prep ., add to Notes as follows:
"Any ECM may be used."
In AS SPEC LINES, Chevrolet/Pontiac Camaro & Firebird (82-92) 5.7L V-8 LS1, add to Notes as follows:

2025-01-01 STU Merger GT3 to STU

#37486 from Club Racing Board · Rule change · TB 25-01 (2025-01 Fastrack)

Summary

As printed in Fastrack

In STU, Table C, change STU-GT3 charge as follows:
"(Effective January 1, 2026) TABLE C: STU-GT3U"

2025-01-01 STU GT3 TCR Tire allowance

#37494 from Club Racing Board · Rule change · TB 25-01 (2025-01 Fastrack)

Summary

As printed in Fastrack

In STU, Table C, GT3 TCR, add to Notes the following:
"May run DOT approved tire with maximum section width of 275 with 100 pound weight adder. May not run A compound with
275."

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

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

Summary

As printed in 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)

Summary

As printed in 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 STU BMW N54/N55 Engine Allowance Follow Up

#37447 from Martin Sarukhanyan · Rule change · TB 25-03 (2025-03 Fastrack)

Summary

As printed in Fastrack

In STU Spec Lines, Table A, classify BMW N54/N55 as follows:
STU Maximum Displacement
(cc's) Minimum Weight Notes
BMW N54/N55 3.0 Chart +3% (DI) Short blocks, heads, and intakes may be
freely swapped within these engine
designations. N54 twin turbo not allowed

2025-03-01 STU STU Mini Cooper pulley size clarification re: letter #36980

#37717 from Aaron Fitzsimmons · Rule change · TB 25-03 (2025-03 Fastrack)

Summary

As printed in Fastrack

In STU Spec Lines, Mini Cooper S SC, add to notes:
2100: "May run a 2.285 2.185 diameter pulley."

2025-03-01 STU Question About a Weight Modifier

#37782 from Peter St Pierre · Rule change · TB 25-03 (2025-03 Fastrack)

Summary

As printed in Fastrack

In STU Spec Lines, Table A, Honda K20C1 Turbo I4, add to Notes the following:
"The 3% DI weight adder does not need to be applied."

2025-03-01 AS Race memo

#37902 from American Sedan Committee · Rule change · TB 25-03 (2025-03 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, change Notes as follows:
Cadillac CTS-V (04-07) Restricted Prep. 6.0L V8 (Aluminum block, Aluminum heads), LS2, 2 valves/cylinder:
"Any ECM maybe used."
Chevrolet Camaro, Pontiac Firebird (70-81) Restricted Prep. 6.2L V8 (Aluminum Block, Aluminum Heads), 2 valves per cylinder:
"Any ECM maybe used."
Chevrolet/Pontiac Camaro & Firebird (82-92)s 5.7L V-8 LS1 (Aluminum Block, Aluminum Heads) 2 valves per cylinder:
"Any ECM maybe used."
Chevrolet/Pontiac Camaro & Firebird (93-02):

2025-03-01 STU Increase Minimum Weight

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

Summary

As printed in Fastrack

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

2025-04-01 AS Flotek Head Plunge Cut Inconsistencies

#37502 from Pamela Richardson · Rule change · TB 25-04 (2025-04 Fastrack)

Summary

As printed in Fastrack

In GCR, Section 9.1.6., replace Figure 1 Value Seat Cutting Dimensions with the following:

2025-04-01 AS Notes clean up

#37693 from American Sedan Committee · Rule change · TB 25-04 (2025-04 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, change/add to Notes as follows:
Cadillac CTS-V (04-07):
"Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is taken from the perimeter of the
stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a safety fuel cell. Any ECM maybe used. The
Drive Shaft Shop, Axle shaft part #'s 510220/510221 permitted."
Chevrolet Camaro, Pontiac Firebird (70-81) Full Prep:
"Engine built to A/S Build Sheet specifications with the following: Head Casting #s: 14101081, 14014416 Port Volume (Max.): 081
casting: 170.00 cc IN/65.00 EX; 416 Casting 168.00cc IN/60.00 EX with a 250 lb. weight reduction. Edelbrock Cylinder Head Part

2025-05-01 STU Wheel Size Inconsistency

#38018 from David Fiorelli · Rule change · TB 25-05 (2025-05 Fastrack)

Summary

As printed in Fastrack

In GCR, Section 9.1.4.1.F.1., change as follows:
"Wheels may not exceed 18 inches in diameter. or 8.0 inches in width for vehicles 2950 lbs. and under minimum allowed race
weight. Vehicles over 2850 minimum allowed race weight may use a 9 inch wide wheel. Cars equal to or less than 2,850 lbs.
minimum allowed race weight may not use wheels wider than 8 inches. Cars greater than 2,850 lbs. minimum allowed race
weight may not use wheels wider than 9 inches."

2025-05-01 AS Errors and Omission

#38055 from American Sedan Committee · Rule change · TB 25-05 (2025-05 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, Ford Mustang GT 5.0l (15-17), Flat Plate Restrictor Size, change as follows:
"67mm 64mm"

2025-05-01 P Add missing punctuation marks

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

Summary

As printed in 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 AS Request to Add LS1/LS6 Intakes for 5.3L Truck Engine EnO

#38197 from Jim Clark · Rule change · TB 25-05 (2025-05 Fastrack)

Summary

As printed in Fastrack

In GCR, Section 9.1.6.F., add the following to Intake Part #’s:
"17113697, 19418185, 89017230, 89017363, 89017364, and 89017365, 12561269 and 88894095"

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

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

Summary

As printed in 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 AS Errors and Omissions

#38234 from American Sedan Committee · Rule change · TB 25-06 (2025-06 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, Ford Mustang GT (05-14) with Restricted Prep Engine, add to Gear Ratios the following:
"or 3.66, 2.43, 1.69, 1.32, 1.00, .65"

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2025-07-01 STU 2.8-3.2L N/A Engine Allowances

#38007 from Ben Slechta · Rule change · TB 25-07 (2025-07 Fastrack)

Summary

As printed in Fastrack

In GCR, Section 9.1.4.G.1, add the following:
"A maximum section width of 245 is permitted. Cars over 3150 lbs. may run a 275 tire with a 2% weight adder."

2025-07-01 AS RE: Previous Letter 37695 Update

#38245 from Michael Kamalian · Rule change · TB 25-07 (2025-07 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, Ford Mustang GT 5.0 (2018-), change Weight as follows:
"3600 3525"

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe

2025-07-01 STU 2006-2015 Mazda Miata Intake Manifold

#38422 from German Candelario Candelario · Rule change · TB 25-07 (2025-07 Fastrack)

Summary

As printed in Fastrack

In STU, Table A, Mazda MZR (LF, L3, L5), change Notes as follows:
"May use Goodwin Part # 61-2510 or Gato Performance Part #31972 Intake manifold . "

2025-07-01 STU Requesting Approval of the JDM Honda h23a

#38489 from Eric Fiest · Rule change · TB 25-07 (2025-07 Fastrack)

Summary

As printed in Fastrack

In STU, Table B, classify Honda JDM H23a as follows:
STU Maximum Displacement (cc's) Minimum Weight Notes
Honda JDM H23a 2259 Chart Must meet all ST engine regulations.

2025-08-01 STU STU-TCR Adjustments

#38723 from Club Racing Board · Rule change · TB 25-08 (2025-08 Fastrack)

Summary

As printed in Fastrack

In STU Spec Lines, Table C: STU-GT3U, GT3-TCR, change as follows: Remove the current TCR spec line and add the TCR spec lines
from GT3 that are being removed, adding the below to the notes.
"DOT approved tire with maximum section width of 245. May run DOT approved tire with maximum section width of 275 with
100 150 pound weight adder. May not run A-compound with 275. STU-TCR spitters and side valance must comply with
9.1.4.D.3.f. STU-TCR chassis ride height must comply with 9.1.4.1.A.1."

2025-08-01 STU Lotus Weight Reduction

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

Summary

As printed in 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)

Summary

As printed in 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)

Summary

As printed in 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)

Summary

As printed in Fastrack

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

2025-09-01 STU Lotus Weight Reduction E&O

#38919 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)

Summary

As printed in Fastrack

In STU Table B: Alternate Vehicle and Engine Allowances, change Weight as follows:
Lotus Elise SC/ Lotus Exige SC: "2450 2250"

2025-09-01 P Clarify spec line cars language

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

Summary

As printed in 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.

2025-11-01 AS Cadillac CTS-V BOP Weight Change

#38640 from Alex Lozano · Rule change · TB 25-09 (2025-09 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, Cadillac CTS-V (04-07) Restricted Prep., change Weight as follows:
"(Effective 11/1/2025) 3450 3400"

2025-11-01 STU Non-Homologated Engine Swaps - Specifically K24A2 w/ Honda CRZ

#38746 from William Rori · Rule change · TB 25-09 (2025-09 Fastrack)

Summary

As printed in Fastrack

In STU Spec Lines, Table B: Alternate Vehicle and Engine Allowances, Honda K24, change Weight as follows:
"(Effective 11/1/2025) Chart + 2%"

2025-12-01 STU Turbo Inlet Restrictor Table

#38961 from John Weisberg · Rule change · TB 25-12 (2025-12 Fastrack)

Summary

As printed in Fastrack

In GCR, Section 9.1.4.H.3, change chart as follows:

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

2025-12-01 STU 275 Tire Rule

#38983 from Peter Federlin · Rule change · TB 25-12 (2025-12 Fastrack)

Summary

As printed in Fastrack

In GCR, Section 9.1.4.G.1., change as follows:
"A maximum section width of 245 is permitted. Cars over 3150 lbs. may run a 275 tire with a 2% weight adder."

2025-12-01 AS 1994 Mustang Spec Line Request

#39104 from Barry Borgschatz, Jr · Rule change · TB 25-12 (2025-12 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, Ford Mustang GT(94-04) with Restricted Prep Engine, add to notes the following:
"Ford Motorsport #M-6250-F303 camshaft is permitted."

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2025-12-01 STU STU Honda Engine weight penalty

#39375 from Super Touring Committee · Rule change · TB 25-12 (2025-12 Fastrack)

Summary

As printed in Fastrack

In STU Spec Lines, Table B: Alternate Vehicle and Engine Allowances, change Minimum Weight as follows:
Honda K20: "Chart + 2%"
Honda K24: "Chart + 2%"

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

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

Summary

As printed in 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 AS Restrictor Plate Change for Gen 2 Ford Coyote Engine

#39501 from American Sedan Committee · Rule change · TB 26-01 (2026-01 Fastrack)

Summary

As printed in Fastrack

In AS Spec Lines, change Restrictor as follows:
Ford Mustang Incl. Cobra and Cobra R (79-93) and Mercury Capri (79-86) with Restricted Prep Engine: "64 mm 61 mm"
Ford Mustang GT (94-04) with Restricted Prep Engine: "64 mm 61 mm"
Ford Mustang Coupe GT (05-14) Restricted Prep 5.0L/6 speed 4 valves per cylinder: "64 mm 61 mm"
Ford Mustang GT (05-14) with Restricted Prep Engine: "64 mm 61 mm"
Ford Mustang GT 5.0L (15-17) Restricted Preparation: "64 mm 61 mm"

2026-01-01 STU Request for Permission on Aftermarket Turbo Kit and Intake

#39529 from John Grim · Rule change · TB 26-01 (2026-01 Fastrack)

Summary

As printed in Fastrack

In STU Spec Lines, Table A: Alternate Vehicle and Engine Allowances, Mazda MZR (LF, L3, L5), change Notes as follows:
"Short blocks, heads, and intakes may be freely swapped within these engine designations. May use Goodwin Part # 61-
2510 or, Gato Performance Part #31972 or Jack Spania Racing 70 mm sheet-metal aluminum Intake manifold. Must use stock
throttle body or Acura part number 16400-PND-A17."
In STU Spec Lines, Table A: Alternate Vehicle and Engine Allowances, classify Mazda MZR (LF, L3, L5) Turbo as follows:
STU Maximum Displacement (cc's) Minimum Weight Notes
Mazda MZR (LF, L3,
L5) Turbo

2026-02-01 AS Edelbrock manifold (& timing kit) to Chevy LS Spec Lines Request

#39055 from Jason Smith · Rule change · TB 26-01 (2026-01 Fastrack)

Summary

As printed in Fastrack

In GCR, Section 9.1.6.D.2.h.2., add the following:
"(Effective 2/1/2026) i. Weight based on full preparation chassis choice spec line for GM LM7 5.3L
Carburetor Option:
Must use the full prep 4776 holly carburetor and spacer gasket
Edelbrock Performer RPM 71187 intake manifold
MSD 6014 ignition box
(Edelbrock part # kit 7118)"