BoP Lab / Buttonwillow Raceway Park
This track has been raced on 4 configurations (The Circuit, 2.57 mi; 19, 2.92 mi; 1.83 mi; 3.02 mi). Laps on different configurations are not comparable, so only events on the 2.57 mile layout are shown; switch above to see the others.
7 laps are left out as timing errors (far too short to be a lap of this track). The rest of those sessions, sectors included, is used.
| Pos | Car | Driver | Class | # | Lap | Theoretical | Qual | Race | 5-lap stint | Consistency | Trap | S1 | S2 | S3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Chevrolet | Bob Blizzard | GTX | 9 | 1:49.569 B-P | 1:49.051 | 124.2 B-P | 29.869 B-P | 31.704 B-P | 47.478 B-P | ||||
| 2 | Ford Mustang GT4 | Rob Scholl | GTX | 22 | 1:49.596 B-R2 | 1:48.800 | 1:49.596 B-R2 | 1:50.003 B-R2 | +0.917 B-R2 | 116.4 B-R2 | 30.070 B-R2 | 31.820 B-R1 | 46.910 B-R2 | |
| 3 | Mazda RX-3 | Tony Rivera | STU | 09 | 1:50.913 A-Q2 | 1:50.870 | 1:50.913 A-Q2 | 1:52.737 A-R2 | 1:54.126 A-R2 | +2.638 A-R2 | 135.2 A-Q2 | 30.415 A-Q2 | 32.456 A-Q2 | 47.999 A-Q2 |
| 4 | Mazda Miata | Whitfield Gregg | STU | 17 | 1:51.602 B-P | 1:51.602 | 2:02.264 B-Q2 | 2:01.538 B-R1 | 2:02.222 B-R1 | +1.271 B-R1 | 116.3 A-Q1 | 30.652 B-P | 32.263 B-P | 48.687 B-P |
| 5 | BMW M3 | Wilson Powell | STU | 77 | 1:52.380 B-P | 1:52.164 | 1:55.401 B-Q1 | 1:53.843 B-R1 | 1:54.699 B-R1 | +1.965 B-R1 | 102.6 B-R1 | 30.577 B-P | 32.372 B-P | 49.215 B-P |
| 6 | Honda S2000 | Rylan Hazelton | STU | 49 | 1:53.640 B-R1 | 1:53.140 | 1:55.834 B-Q1 | 1:53.640 B-R1 | 1:54.534 A-R2 | +0.714 A-R2 | 134.8 A-R2 | 30.582 B-R1 | 32.779 B-R1 | 49.779 A-R2 |
| 7 | Porsche 981 Cayman | Moze Cowper | GTX | 111 | 1:54.892 A-Q1 | 1:54.066 | 1:54.892 A-Q1 | 1:55.330 A-R2 | 1:55.654 A-R2 | +0.622 A-R2 | 146.0 A-R1 | 31.377 A-R1 | 32.983 A-R2 | 49.706 A-Q1 |
| 8 | BMW 330 | Sean Lovett | STU | 37 | 1:56.492 A-Q2 | 1:56.426 | 1:56.492 A-Q2 | 1:57.049 A-R2 | 1:57.605 A-R2 | +1.649 A-R2 | 133.7 A-R2 | 31.816 A-Q2 | 33.669 A-Q1 | 50.941 A-Q2 |
| 9 | Nissan 300ZX | James Slechta | STU | 75 | 1:59.183 A-Q2 | 1:59.183 | 1:59.183 A-Q2 | 2:00.458 A-R2 | 2:01.009 A-R2 | +0.921 A-R2 | 132.0 A-Q1 | 32.882 A-Q2 | 34.528 A-Q2 | 51.773 A-Q2 |
| 10 | Chevrolet Camero | Michael Arnheiter | GTX | 63 | 1:59.339 B-P | 1:56.800 | 124.8 B-P | 32.354 B-P | 33.705 B-P | 50.741 B-P | ||||
| 11 | Mazda MX-5 | Oscar Jackson | STU | 161 | 1:59.707 B-R2 | 1:58.888 | 1:59.707 B-R2 | 1:59.952 B-R2 | +1.112 B-R2 | 103.9 B-R2 | 32.339 B-R2 | 34.219 B-R2 | 52.330 B-R2 | |
| 12 | Mazda RX-7 | Michael Lewis | STU | 32 | 2:00.248 A-R1 | 2:00.179 | 2:00.248 A-R1 | 2:02.190 A-R2 | +1.431 A-R2 | 130.4 A-R1 | 32.729 A-R1 | 34.570 A-R1 | 52.880 A-R1 | |
| 13 | Mazda MX-5 | Dale Shoemaker | STU | 52 | 2:01.642 B-R2 | 2:01.176 | 2:04.115 B-Q1 | 2:01.642 B-R2 | 2:02.793 B-R2 | +2.442 B-R2 | 125.9 A-Q2 | 32.956 B-R2 | 34.983 B-R2 | 53.237 B-R2 |
One row per driver and car (a driver who changed cars has a row for each). Each cell is that driver's best in that car across the selected events, with the session it was set in. Best 5-lap stint is the mean of the driver's quickest five consecutive race laps, and consistency is how far their median race lap sat behind their best in that race (small is a driver who does it every lap); both come from the race with the best stint. The fastest in each column is purple, and a car whose best lap is more than 115% of the fastest in its class is greyed (marked ">115%" beside the driver) and left out of the colour scale. Click a column to sort, a row to highlight it. Theoretical lap is the sum of the best sectors, whichever laps they came from, and never slower than the best lap (where a car's fastest laps were recorded without sector times, its best lap is used). The 115% mark is about the car's best lap only: a car whose best lap is within 115% of the fastest in its class is never marked. Greyed sectors with no theoretical lap mean the sector times on file do not add up to a believable lap. Letters refer to the events above; Q is qualifying, R a race.
Sectors are numbered in lap order from start/finish, whatever each event's timing called them; the loop names are SCCA timing's.
| Car | Class | Drivers | Lap | Qual | Race | Trap | S1 | S2 | S3 |
|---|---|---|---|---|---|---|---|---|---|
| Chevrolet | GTX | 2 | 1:49.569Bob Blizzard | 124.8Michael Arnheiter | 29.869Bob Blizzard | 31.704Bob Blizzard | 47.478Bob Blizzard | ||
| Chevrolet | GTX | 1 | 1:49.569Bob Blizzard | 124.2Bob Blizzard | 29.869Bob Blizzard | 31.704Bob Blizzard | 47.478Bob Blizzard | ||
| Chevrolet Camero | GTX | 1 | 1:59.339Michael Arnheiter | 124.8Michael Arnheiter | 32.354Michael Arnheiter | 33.705Michael Arnheiter | 50.741Michael Arnheiter | ||
| Ford Mustang GT4 | GTX | 1 | 1:49.596Rob Scholl | 1:49.596Rob Scholl | 116.4Rob Scholl | 30.070Rob Scholl | 31.820Rob Scholl | 46.910Rob Scholl | |
| Mazda RX-3 | STU | 1 | 1:50.913Tony Rivera | 1:50.913Tony Rivera | 1:52.737Tony Rivera | 135.2Tony Rivera | 30.415Tony Rivera | 32.456Tony Rivera | 47.999Tony Rivera |
| Mazda Miata | STU | 1 | 1:51.602Whitfield Gregg | 2:02.264Whitfield Gregg | 2:01.538Whitfield Gregg | 116.3Whitfield Gregg | 30.652Whitfield Gregg | 32.263Whitfield Gregg | 48.687Whitfield Gregg |
| BMW M3 | STU | 1 | 1:52.380Wilson Powell | 1:55.401Wilson Powell | 1:53.843Wilson Powell | 102.6Wilson Powell | 30.577Wilson Powell | 32.372Wilson Powell | 49.215Wilson Powell |
| Honda S2000 | STU | 1 | 1:53.640Rylan Hazelton | 1:55.834Rylan Hazelton | 1:53.640Rylan Hazelton | 134.8Rylan Hazelton | 30.582Rylan Hazelton | 32.779Rylan Hazelton | 49.779Rylan Hazelton |
| Porsche 981 Cayman | GTX | 1 | 1:54.892Moze Cowper | 1:54.892Moze Cowper | 1:55.330Moze Cowper | 146.0Moze Cowper | 31.377Moze Cowper | 32.983Moze Cowper | 49.706Moze Cowper |
| BMW 330 | STU | 1 | 1:56.492Sean Lovett | 1:56.492Sean Lovett | 1:57.049Sean Lovett | 133.7Sean Lovett | 31.816Sean Lovett | 33.669Sean Lovett | 50.941Sean Lovett |
| Nissan 300ZX | STU | 1 | 1:59.183James Slechta | 1:59.183James Slechta | 2:00.458James Slechta | 132.0James Slechta | 32.882James Slechta | 34.528James Slechta | 51.773James Slechta |
| Mazda MX-5 | STU | 2 | 1:59.707Oscar Jackson | 2:04.115Dale Shoemaker | 1:59.707Oscar Jackson | 125.9Dale Shoemaker | 32.339Oscar Jackson | 34.219Oscar Jackson | 52.330Oscar Jackson |
| Mazda RX-7 | STU | 1 | 2:00.248Michael Lewis | 2:00.248Michael Lewis | 130.4Michael Lewis | 32.729Michael Lewis | 34.570Michael Lewis | 52.880Michael Lewis |
The best any driver of each car managed across the selected events, with who set it. Spellings and model years of the same car are grouped; click a row marked ▸ to see each version. Grouping is worked out from the names, so tell us if two cars are wrongly merged or split.
#33737 from Eric Heinrich · Rule change · TB 23-03 (2023-03 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"
#33827 from Brandon Steinhauer · Rule change · TB 23-04 (2023-04 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.
#33784 from James Rogersn · Rule change · TB 23-05 (2023-05 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
GCR Section 9.4.
In GT Spec Lines, GT1Engines - classify Ford V8 as follows:
GT1 Engines - Ford
Engine
Family
Engine Type Bore x
A specification table follows in the original; it is not shown here.
#34043 from Alex Kirby · Rule change · TB 23-06 (2023-07 Fastrack)
In GTX Spec Lines, classify Ligier LMP3 as follows:
GTX - MISC
Make Model Engine Restrictor
(mm) Weight (lbs) Notes
Ligier LMP3 3.7L NA 2203
#34173 from Bob Monette · Rule change · TB 23-06 (2023-07 Fastrack)
In GTX Spec Lines, classify Ligier JSP4 as follows:
GTX - MISC
Make Model Engine Restrictor
(mm) Weight (lbs) Notes
#34449 from Club Racing Board · Rule change · TB 23-06 (2023-05 Fastrack)
In STU Spec Lines, Toyota GR Cup (2022-), classify as follows:
A specification table follows in the original; it is not shown here.
#34453 from David Gomberg · Rule change · TB 23-12 (2023-12 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
GTL Cars 364
GTA Cars 377
P2 Engine Table B.1
2010 and older
Stock Kawasaki
38.5mm
minimum width 52 inches. AMAC-AM5:
minimum width 54 inches.
P2 Engine Table B.1
2008 and older
Stock Engine Suzuki,
Yamaha,
Honda, BMW
38.5mm
P2 Engine Table B.2 Not required
P2 Engine Table B.3 38.5mm
Modified Engine
950 lbs.
1005cc max
P2 Engine Table B.1 37mm
P2 Engine Table B.2 Not required
P2 Engine Table B.3 39mm
Stock Engine
1050 lbs.
#34956 from Demetrio Bilbatua · Rule change · TB 24-01 (2024-01 Fastrack)
In GTX Spec Lines, classify KTM as follows:
GTX – KTM
Make Homologation Model Restrictor
(mm) Weight (lbs) Notes
#35066 from Jose Osiris Pena · Rule change · TB 24-02 (2024-01 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"
#35261 from Butch Kummer · Rule change · TB 24-02 (2024-01 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.”
#35437 from Grand Touring Committee · Rule change · TB 24-02 (2024-01 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.”
#35439 from Grand Touring Committee · Rule change · TB 24-02 (2024-02 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.”
#35453 from Aaron Fitzsimmons · Rule change · TB 24-03 (2024-03 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."
#35464 from Macey Urso · Rule change · TB 24-03 (2024-03 Fastrack)
In STU Spec Lines, BMW S54 B32 OEM, add to Notes as follows:
"Dry Sump oiling system permitted."
#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"
#36255 from David Fiorelli · Rule change · TB 24-08 (2024-08 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"
#36980 from Aaron Fitzsimmons · Rule change · TB 24-11 (2024-11 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."
#37138 from Christopher Childs · Rule change · TB 24-12 (2024-12 Fastrack)
In GCR, Section 9.1.4.M.18., change as follows:
"18. Allow alternate front wheel front hubs, Mazda Motorsports Development Part #0000-04-5HUB-S1, for the 90-05 Mazda
Miata: Mazda Motorsports Development Part #0000-04-5HUB-S1."
#37146 from Martin Sarukhanyan · Rule change · TB 24-12 (2024-12 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.
#36685 from Mike McLaughlin · Rule change · TB 25-01 (2025-01 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."
#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.
#37486 from Club Racing Board · Rule change · TB 25-01 (2025-01 Fastrack)
In STU, Table C, change STU-GT3 charge as follows:
"(Effective January 1, 2026) TABLE C: STU-GT3U"
#37494 from Club Racing Board · Rule change · TB 25-01 (2025-01 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."
#37447 from Martin Sarukhanyan · Rule change · TB 25-03 (2025-03 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
#37717 from Aaron Fitzsimmons · Rule change · TB 25-03 (2025-03 Fastrack)
In STU Spec Lines, Mini Cooper S SC, add to notes:
2100: "May run a 2.285 2.185 diameter pulley."
#37782 from Peter St Pierre · Rule change · TB 25-03 (2025-03 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."
#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"
#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
#38018 from David Fiorelli · Rule change · TB 25-05 (2025-05 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 raceweight. 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."
#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” wheelsallowd with a 3% weight addition. GT3 cars utilizing 15”x7” wheels are limited to a maximum section width of 225 with a 25pound 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."
#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."
#38007 from Ben Slechta · Rule change · TB 25-07 (2025-07 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."
#38422 from German Candelario Candelario · Rule change · TB 25-07 (2025-07 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 . "
#38489 from Eric Fiest · Rule change · TB 25-07 (2025-07 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.
#38723 from Club Racing Board · Rule change · TB 25-08 (2025-08 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 with100 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."
#38772 from Club Racing Board · Rule change · TB 25-08 (2025-08 Fastrack)
In 9.1.2. GT2/ST Spec Lines, Lotus Evora GT4, change Weight as follows:
"2750 2700"
In STU Table B: Alternate Vehicle and Engine Allowances, change Weight as follows:
Lotus Elise Cup R: "2300 2250"
Lotus Elise SC/ Lotus Exige SC: "2300 25502500 2450"
#38919 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)
In STU Table B: Alternate Vehicle and Engine Allowances, change Weight as follows:
Lotus Elise SC/ Lotus Exige SC: "2450 2250"
#38746 from William Rori · Rule change · TB 25-09 (2025-09 Fastrack)
In STU Spec Lines, Table B: Alternate Vehicle and Engine Allowances, Honda K24, change Weight as follows:
"(Effective 11/1/2025) Chart + 2%"
#38961 from John Weisberg · Rule change · TB 25-12 (2025-12 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.
#38983 from Peter Federlin · Rule change · TB 25-12 (2025-12 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."
#39375 from Super Touring Committee · Rule change · TB 25-12 (2025-12 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%"
#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.
#39529 from John Grim · Rule change · TB 26-01 (2026-01 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
Varies Chart Short blocks, heads, and intakes may be freely
swapped within these engine designations. May
use Jack Spania Racing 70 mm sheet-metal
aluminum Intake manifold. Must use stock
throttle body or Acura part number 16400-PND-
A17. Fab9 Tuning bottom-mount turbo kit
approved with one of the STU approved Turbos.
What the rules allowed changed as listed; this does not say what any particular car ran.