GT3 + STU 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.

2023-05-01 GT3 Please classify Fields Cardinal V8

#33784 from James Rogersn · Rule change · TB 23-05 (2023-05 Fastrack)

Summary

As printed in Fastrack

In GT Spec Lines, GT1 Cars - Fields Cardinal, classify Fields Cardinal V8 as follows:
GT1 Cars – Fields Cardinal
Model Years Body Style Drive-
line
Wheel-
base (in)
Notes
Fields Cardinal V8 2023 2 Dr. RWD 92.0 Roll Cage MUST be modified to comply with

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

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 GT3 Addendum to letter 33913, GT3 DOT tires.

#34627 from Grand Touring Committee · Rule change · TB 23-08 (2023-05 Fastrack)

Summary

As printed in Fastrack

In GCR section 9.1.2.F.7.c.10.b, add the following:
"Any racing tire including DOT is allowed in GT3. Cars using 15” American Racer 23.5-10.0-15, bias ply, non-belted tire may do so
without the weight penalty."

2023-10-01 GT3 Classify Honda B20 engine in GT3 CRX

#34781 from Taz Harvey · Rule change · TB 23-10 (2023-10 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines - HONDA, classify B20 as follows:
GT3 Engines - HONDA

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

2023-11-01 GT3 GT3 TCR 200 TW tires

#34993 from Grand Touring Committee · Rule change · TB 23-11 (2023-11 Fastrack)

Summary

As printed in Fastrack

In GT3 Spec Lines, GT3-TCR, change Notes as follows:
Audi RS3 LMS (16-20) @ 3170 lbs: "Must use 200 tread wear any DOT tires. No tire shaving permitted. Stock TCR wheels only."
Audi RS3 LMS (16-20) @ 3100 lbs: "Must use 200 tread wear any DOT tires."
Honda Civic Type R (16-20): "Must use 200 tread wear any DOT tires."
Hyundai 130 N (16-20): "Must use 200 tread wear any DOT tires."
Volkswagen Golf GTi (16-20) @ 3177 lbs: "Must use 200 tread wear any DOT tires."
Volkswagen Golf GTi (16-20) @ 3100 lbs: "Must use 200 tread wear any DOT tires."

2023-12-01 GT3 Errors in GTCS Headings and Use of the Terms Category and ClassChange existing GTL and GTA Rules

#34453 from David Gomberg · Rule change · TB 23-12 (2023-12 Fastrack)

Summary

As printed in Fastrack

from the current (or before) Table of Contents (TOC), to what is shown in the after TOC.
GTL spec lines will now be contiguous with GT2 and 3 spec lines.
GTA category and spec lines will be moved and renumbered behind GTL. GTA Section will not change but page numbers will, (as
shown in Red italics).
9.1.2.F. GT-2, 3, LITE Category Specifications 314
GT2 Cars 327
GT2/ST 341
GT3 Cars 348

2023-12-01 GT3 Toyota Engine Classification Request

#35019 from warren Montague · Rule change · TB 23-12 (2023-09 Fastrack)

Summary

As printed in Fastrack

In GT3 TOYOTA Engines, classify Toyota 3S as follows:
GT3 TOYOTA Engines -

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

2023-12-01 GT3 GT3 2.0L SIR & weight

#35171 from Grand Touring Committee · Rule change · TB 23-12 (2023-09 Fastrack)

Summary

As printed in Fastrack

In GT3 Spec Lines, GT3 Cars, change as follows:
"Acura F20C 1997cc 32mm SIR May run unrestricted at 2195lbs.
K20A 1988cc 32mm SIR May run unrestricted at 2195lbs.
Audi 1984cc 32mm SIR May run unrestricted at 2195lbs.
BMW 1895cc 32mm SIR May run unrestricted at 2195lbs.
Chevrolet 1998cc 32mm SIR May run unrestricted at 2195lbs.
Chrysler/Dodge/Plymouth 1997cc 32mm SIR May run unrestricted at 2195lbs.
Ginetta MZR 1999cc 32mm SIR May run unrestricted at 2195lbs.

2024-01-01 GT3 Disenfranchised GT2 RX7.

#35028 from Richard Smith · Rule change · TB 24-01 (2024-01 Fastrack)

Summary

As printed in Fastrack

In GT3 Spec Lines, reduce all disenfranchised GT2 cars from 150 lbs to 75 lbs.GT3 MAZDA: Body: RX7 NA 2 DR. RWD 95.3 /
95.5 / 95.7 SP – Please review and provide appropriate layout for GCR.
In GT3 Spec Lines, Engines - MAZDA, add to Notes as follows:
12A Peripheral Port at 2300 lbs.: "Disenfranchised GT2* add 75 lbs."
13B Bridgeport: "Disfranchised GT2 add 75 lbs."
13B Peripheral Port: "Disfranchised GT2 add 75 lbs."

2024-01-01 GT3 Turbo Help

#35042 from Chris Edens · Rule change · TB 24-01 (2024-01 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines - Mazda Spec Lines, Mazda BP4W Turbocharged OEM engine, change Weight as follows:
"2060 1960"

2024-01-01 GT3 Competition Adjustment Request for 13B Peripheral Port

#35100 from Richardo Hollingshead · Rule change · TB 24-01 (2024-01 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines - MAZDA Spec Lines, 13B Peripheral Port, change Weight as follows:
"2200 2100"

2024-01-01 GT3 Request to Include Toyota GR 86 in GT3

#35197 from Erik Madsen Madsen · Rule change · TB 24-01 (2024-01 Fastrack)

Summary

As printed in Fastrack

In GT3 Cars - TOYOTA Spec Lines, classify DR86 as follows:
GT3 Cars - TOYOTA
Model Years Body Style Driveline Wheelbase (in) Notes
DR86 2021-2024 2 DR RWD 101.3

2024-01-01 GT3 Fastrack Toyota 3S Correction

#35258 from warren Montague · Rule change · TB 24-01 (2024-01 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines - Toyota, 3S, change as follows:
Bore: "84.2 86.0"
Stroke: "90.1 86.0"

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"

2024-02-01 GT3 Request to Include Toyota FA24D Engine for use in GT3

#35199 from Erik Madsen Madsen · Rule change · TB 24-02 (2024-02 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines - Toyota, classify the FA24D as follows: see attachment
GT3 Engines - TOYOTA

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

2024-02-01 GT3 Rear Blade Spoiler Clarification

#35261 from Butch Kummer · Rule change · TB 24-02 (2024-01 Fastrack)

Summary

As printed in Fastrack

In GCR Section 9.1.2.G (GTA Category Specifications), change as follows:
“9.1.2.G.III.I
The single-plane rear spoiler must be mounted at an angel angle from 50 to 75 degrees (perpendicular to the ground
being 90 degrees) and may not extend beyond the rear bumper when viewed from directly above the rear
bumper. Spoilers must be a minimum of .063 aluminum or Lexan and may vary in overall height to match the contours
of the bodywork. The rear spoiler dimensions shall not exceed 59.0 inches wide by 5.0 inches in height, (measured on
the material surface) , or 295.0 square inches total surface area. Braces to prevent spoiler deflection are allowed, but
may serve no other purpose.”

2024-02-01 GT3 GT Direct Injection allowance and rules

#35437 from Grand Touring Committee · Rule change · TB 24-02 (2024-01 Fastrack)

Summary

As printed in Fastrack

In GCR, Section 9.1.2.F.7.5.E. change as follows:
“Direct Injection is not permitted only if it came OE and must be installed using only OE high pressure pump(s), hard and
soft hoses and injectors.”

2024-02-01 GT3 GT2/3 remove Direction Injection not allowed in Spec line notes

#35439 from Grand Touring Committee · Rule change · TB 24-02 (2024-02 Fastrack)

Summary

As printed in Fastrack

In GT2/3 modify Spec Line notes as follows:
GT2:
Nissan: “Direct Injection not permitted, may be used per 9.1.2.F.7.5.E.”
GT3:
Mazda: “Direct Injection not permitted, may be used per 9.1.2.F.7.5.E.”
Mitsubishi 4G93: “Direct Injection not permitted, may be used per 9.1.2.F.7.5.E. ”
Nissan QR25DE/DD 1988cc: “Direct Injection not permitted, may be used per 9.1.2.F.7.5.E.”
Nissan QE25DE/DD 2489cc: “Direct Injection not permitted, may be used per 9.1.2.F.7.5.E.”

2024-02-01 GT3 Edit GT3 Nissan QR25DE/DD spec line

#35442 from Grand Touring Committee · Rule change · TB 24-02 (2024-02 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines - Nissan QR25DE/DD, change as follows:
11111’QR25 0DE/DD”

2024-03-01 GT3 Miata Turbo Clarification

#35386 from Chris Edens · Rule change · TB 24-03 (2024-03 Fastrack)

Summary

As printed in Fastrack

In GCR, Section 9.1.2.F.7.i.3. GT3 Turbocharged Built Engines:, 1401-1850, change as follows:
Restrictor: "34 35 mm"
Weight (lbs): "2250 2350"
In GCR, Section 9.1.2.F.7.i.3. GT3 Turbocharged Built Engines:, relocate chart to 9.1.2.F.7.h.6.d., as follows:
"d. Borg-Warner EFR6258

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."

2024-05-01 GT3 Request for Spec Line 1010 Reconsideration

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

Summary

As printed in Fastrack

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

2024-05-01 GT3 Mazda MZR Engines

#35753 from Sam Fouse · Rule change · TB 24-05 (2024-05 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines-FORD, Duratech, add to Notes as follows:
"Hood bulge allowed w/ no openings."

2024-05-01 GT3 Disenfranchised GT2 Acura RSX to Run GT3

#35773 from Robert Stratos · Rule change · TB 24-05 (2024-05 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines -ACURA Spec Lines, K20A, add to Notes as follows:
"RSX body only. Disenfranchised GT2* add 75 lbs."

2024-05-01 GT3 Toyota 4Y Engine Request

#35885 from Scott Schick · Rule change · TB 24-05 (2024-05 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines - TOYOTA, classify 4Y as follows:
GT3 Engines - TOYOTA
Engine
Family
Engine Type Bore x Stroke

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

2024-05-01 GT3 GT3 spec lines clean-up

#36008 from Grand Touring Committee · Rule change · TB 24-05 (2024-05 Fastrack)

Summary

As printed in Fastrack

In GT3 Cars - TOYOTA, change Model as follows:
"DR86 GR86"

2024-05-01 GT3 GT3 Honda spec line clean-up x 2

#36009 from Grand Touring Committee · Rule change · TB 24-05 (2024-05 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines - HONDA Spec Lines, change Engine Family as follows:
"89mm K20C1"
"1973cc K24"

2024-05-01 GT3 GT3 Mazda spec line clean-up x2

#36010 from Grand Touring Committee · Rule change · TB 24-05 (2024-05 Fastrack)

Summary

As printed in Fastrack

In GT3 Cars - MAZDA Spec Lines, change as follows:
Heading: "4 Model"
"Unrestricted 323"
"2195 626"

2024-06-01 GT3 GT3 +1mm SIR add 175lbs. In

#36098 from Grand Touring Committee · Rule change · TB 24-06 (2024-06 Fastrack)

Summary

As printed in Fastrack

GCR, Section 9.1.2.F.7. add the following:
"m. GT3 Rules Concerning Alternate Weights and SIRs.
1. Traditional GT3 cars that that are currently required to run an SIR may run +1mm above spec line listed size size with a 175lb.
weight penalty.
2. Competitors running the alternate SIR must display "+1.mm" on the side of their car next to the new weight."

2024-06-01 GT3 Revised GT3 Built Turbocharged chart

#36100 from Grand Touring Committee · Rule change · TB 24-06 (2024-06 Fastrack)

Summary

As printed in Fastrack

In GCR, Section GT3 9.1.2.13.h.6. GT3 Turbocharger Built Engines, update Chart as follows:
"Engine
Displacement Valves / cyl Restrictor Weight Notes
<1400 4 33 mm 2100
1401-1850 4 35 mm 34 mm 2350 2250
1401-1850 4 35 mm 2350"

2024-07-01 GT3 Correct missed Disenfranchised weight reduction

#36237 from Grand Touring Committee · Rule change · TB 24-07 (2024-07 Fastrack)

Summary

As printed in Fastrack

In GT3 Cars - PONTIAC, Sunfire GT, change Notes as follows:
"150 75"

2024-07-01 GT3 errors & omissions on GT3 Mazda MZR spec lines

#36241 from Grand Touring Committee · Rule change · TB 24-07 (2024-07 Fastrack)

Summary

As printed in Fastrack

In GT3 Spec Lines, GT3 Engines - MAZDA, MZR, eliminate 2nd DOHC in its entirety and change Fuel Induction as
follows:
"Unrestricted"

2024-08-01 GT3 Adding Datsun B110 to List of Approved Cars

#36198 from Vaughn Cooper · Rule change · TB 24-08 (2024-08 Fastrack)

Summary

As printed in Fastrack

In GT3 Spec Lines, classify GT3 Cars - Nissan 1200 (B110) as follows:
GT3 Cars - Nissan
Model Years Body Style Drive-
line
Wheel-
base (in) Notes
1200 (B110) 70-73 2dr RWD 90.6 Must use an engine that is already classified to run
in GT3 or may request an alternate Nissan (Datsun)

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"

2024-08-01 GT3 Honda Civic Type R TCR Weight Reduction Request

#36550 from Nathan Bonneau · Rule change · TB 24-08 (2024-08 Fastrack)

Summary

As printed in Fastrack

In GT3-TCR Spec Lines, change Weight as follows:
Audi RS3 LMS (16-20) SEQ: "31773077"
Audi RS3 LMS (16-20) DSG: "31003000"
Honda Civic Type R (16-20) SEQ: "32103110"
Hyundai I30N (16-20) SEQ: "3254 3154"
Volkswagen GTI (16-20) SEQ: "3177 3077"

2024-09-01 GT3 2024 Mazda 3 TC request for GT3

#36517 from Derrick Ambrose · Rule change · TB 24-09 (2024-09 Fastrack)

Summary

As printed in Fastrack

In GT3-TCR Spec Lines, Mazda, classify 3TC as follows:
TCR - MAZDA
Make Model Trans Power

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

2024-11-01 GT3 GCR GT3 Disfranchised GT2

#36291 from Richard Smith · Rule change · TB 24-09 (2024-09 Fastrack)

Summary

As printed in Fastrack

In GT3 Spec Lines, Engines - MAZDA, Engine Family 13B Bridgeport, change as follows:
Weight: "(Effective 11/1/2024) 2350 2275"
Notes: "(Effective 11/1/2024) Disfranchised GT2*add 75 lbs."
In GT3 Spec Lines, Engines - MAZDA, Engine Family 13B Peripheral Port, change as follows:
Weight: "(Effective 11/1/2024) 2350 2275"
Notes: "(Effective 11/1/2024) Disfranchised GT2*add 75 lbs."

2024-11-01 GT3 Nissan MR20DE Engine Classification Request for GT3

#36791 from Jerold Larson · Rule change · TB 24-11 (2024-11 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines - NISSAN Spec Lines, classify Engine Family MR20DE as follows:
GT3 Engines - NISSAN

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

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."

2024-11-01 GT3 GT3 Mazda 13B PP correction

#37057 from Grand Touring Committee · Rule change · TB 24-11 (2024-11 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines - MAZDA Spec Lines, Engine Family 13B Disp. 2616, change as follows:
Weight (lbs): "2350 2175"
Notes: "Disfranchised GT2* add 75 lbs. Effective 11/1/2024 Disfranchised GT2* weight 2275 2175)"

2024-11-01 GT3 GT3 Mazda12A PP Correction

#37058 from Grand Touring Committee · Rule change · TB 24-11 (2024-11 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines - MAZDA Spec Lines, Engine Family 12A Peripheral Port Disp 2292, change Weight as follows:
"2300 2100"

2024-12-01 GT3 Pontiac Weight and Chassis Adjustment Request

#36938 from Andrew Lott · Rule change · TB 24-12 (2024-12 Fastrack)

Summary

As printed in Fastrack

In GT3 Engines - PONTIAC Spec Lines, LE5 Ecotech, change Weight as follows:
"2345 lbs. 2195 lbs."

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 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 GT3 Correct language regarding OEM Areo Devices

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

Summary

As printed in 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 GT3 VW Funcap weight

#37217 from John Mills · Rule change · TB 25-01 (2025-01 Fastrack)

Summary

As printed in Fastrack

In GT3 Spec Lines, GT3 Engines - VOLKSWAGON, “Fun Cup” Beetle Sealed, add to Weight (lbs) as follows:
"Shall be exempt from consolidation add-on weight of 150 lbs."

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."

2025-03-01 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 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"

2025-05-01 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 GT3 Clarification of GT3U

#38266 from Club Racing Board · Rule change · TB 25-05 (2025-05 Fastrack)

Summary

As printed in Fastrack

In GCR 9.1.2.F.3.9., change as follows:
"All GT3U (Majors and Runoffs) cars shall run at current GT3 race weight plus 150lbs. All GT3U cars shall run one of the following
tire and wheel combinations: A Dot approved tire with maximum section width of 245. GT3U cars base wheel is a maximum of
15”x9”. “18”x9” wheels are allowed with a 3% weight addition. GT3 U cars utilizing 15”x7” wheels are limited to a 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 including the 225 lbs."

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

2025-07-01 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 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 GT3 Declassify TCR Cars from GT3/GT3U

#38569 from Club Racing Board · Rule change · TB 25-08 (2025-08 Fastrack)

Summary

As printed in Fastrack

In GCR Section 9.1.2.F.3.9, add as follows:
"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
including the 225 lbs. TCR cars are ineligible for GT3/GT3U."

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"

2025-09-01 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"

2025-11-01 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 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 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

2026-01-01 GT3 GT3U Ride Height

#39637 from Grand Touring Committee · Rule change · TB 26-01 (2026-01 Fastrack)

Summary

As printed in Fastrack

In GCR, Section 9.1.2.F.3., add the following:
"10. All GT3 cars running in STU must meet the minimum ride height of 3.0" for the main frame rails not including rub blocks and
a 2” minimum for the front spoiler and splitter."