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BoP Lab / Buttonwillow Raceway Park

FF + FA + T1 + STU at Buttonwillow Raceway Park

No mapCal Club 2024, Cal Club 2023

Track map: sectors and speed trap

Track map with timing sectors and speed trap
Shown for: Cal Club 2026 (practice, qualifying, race) · Cal Club 2025 (practice, qualifying, race)
Class · click a class to switch, + to compare alongside
Track configuration
Events

This track has been raced on 4 configurations (The Circuit, 2.57 mi; 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.

6 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.

PosCarDriverClass#LapTheoreticalQualRace5-lap stintConsistencyTrapS1S2S3
1Elan Pro Formula MazdaGreg Labadie 2+ carsFA351:14.588 D-Q21:14.588 D-Q2
2Swift 016Greg Labadie 2+ cars >115%FA351:35.792 A-Q11:35.3511:35.792 A-Q11:37.275 A-R11:37.692 A-R1+3.958 A-R1163.8 A-R126.713 A-Q226.816 A-Q141.822 A-Q1
3BMW M3Ian BarberiT1741:46.465 B-Q21:46.0661:46.465 B-Q21:47.434 B-R11:47.873 B-R1+0.605 B-R1114.9 B-Q2, B-R228.992 B-Q230.811 B-P46.263 B-Q1
4BMW M4 GT4Drew DelmonicoT1431:47.084 B-Q11:46.3161:47.084 B-Q11:47.467 B-R11:48.228 B-R1+1.310 B-R1161.4 B-P29.150 B-Q230.850 B-R146.316 B-P
5SWIFT DB-6 HondaEdward Erlandson 2+ carsFF81:49.259 A-P47.766 A-P
6Mazda RX-3Tony RiveraSTU091:50.913 A-Q21:50.8701:50.913 A-Q21:52.737 A-R21:54.126 A-R2+2.638 A-R2135.2 A-Q230.415 A-Q232.456 A-Q247.999 A-Q2
7Piper DL7-HondaEric PoulsenFF481:51.118 B-R11:50.7441:52.044 B-Q11:51.118 B-R11:51.583 B-R1+3.025 B-R1114.7 B-R130.276 B-R131.650 B-R148.818 B-R1
8Mazda MiataWhitfield GreggSTU171:51.602 B-P1:51.6022:02.264 B-Q22:01.538 B-R12:02.222 B-R1+1.271 B-R1116.3 A-Q130.652 B-P32.263 B-P48.687 B-P
9BMW M3Wilson PowellSTU771:52.380 B-P1:52.1641:55.401 B-Q11:53.843 B-R11:54.699 B-R1+1.965 B-R1102.6 B-R130.577 B-P32.372 B-P49.215 B-P
10SWIFT DB-Edward Erlandson 2+ carsFF541:53.098 A-Q11:53.0411:53.098 A-Q11:54.741 A-R21:56.774 A-R2+1.819 A-R2133.7 A-Q130.951 A-Q132.299 A-Q149.791 A-Q1
11Honda S2000Rylan HazeltonSTU491:53.640 B-R11:53.1401:55.834 B-Q11:53.640 B-R11:54.534 A-R2+0.714 A-R2134.8 A-R230.582 B-R132.779 B-R149.779 A-R2
12Swift Db6Johnnie CreanFF351:54.993 A-R21:54.4901:55.247 A-Q21:54.993 A-R21:56.752 A-R2+1.519 A-R2124.5 A-R231.358 A-Q132.841 A-R250.291 A-R2
13BMW 330Sean LovettSTU371:56.492 A-Q21:56.4261:56.492 A-Q21:57.049 A-R21:57.605 A-R2+1.649 A-R2133.7 A-R231.816 A-Q233.669 A-Q150.941 A-Q2
14Pontiac GTOEd GlessT1431:59.123 A-R11:58.3401:59.760 A-Q21:59.123 A-R12:00.018 A-R2+1.331 A-R2120.7 A-Q132.383 A-R134.587 A-R251.370 A-R2
15Nissan 300ZXJames SlechtaSTU751:59.183 A-Q21:59.1831:59.183 A-Q22:00.458 A-R22:01.009 A-R2+0.921 A-R2132.0 A-Q132.882 A-Q234.528 A-Q251.773 A-Q2
16Ford MustangPratt ColeT181:59.261 B-R21:58.8621:59.261 B-R22:01.195 B-R2+2.608 B-R298.6 B-R232.624 B-R234.661 B-R251.577 B-R2
17Mazda MX-5Oscar JacksonSTU1611:59.707 B-R21:58.8881:59.707 B-R21:59.952 B-R2+1.112 B-R2103.9 B-R232.339 B-R234.219 B-R252.330 B-R2
18Mazda RX-7Michael LewisSTU322:00.248 A-R12:00.1792:00.248 A-R12:02.190 A-R2+1.431 A-R2130.4 A-R132.729 A-R134.570 A-R152.880 A-R1
19Mazda MX-5Dale ShoemakerSTU522:01.642 B-R22:01.1762:04.115 B-Q12:01.642 B-R22:02.793 B-R2+2.442 B-R2125.9 A-Q232.956 B-R234.983 B-R253.237 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

Sectors are numbered in lap order from start/finish, whatever each event's timing called them; the loop names are SCCA timing's.

By car

CarClassDriversLapQualRaceTrapS1S2S3
Pro Formula MazdaFA11:14.588Greg Labadie1:14.588Greg Labadie
Swift 016FA11:35.792Greg Labadie1:35.792Greg Labadie1:37.275Greg Labadie163.8Greg Labadie26.713Greg Labadie26.816Greg Labadie41.822Greg Labadie
BMW M3STU/T121:46.465Ian Barberi1:46.465Ian Barberi1:47.434Ian Barberi114.9Ian Barberi28.992Ian Barberi30.811Ian Barberi46.263Ian Barberi
BMW M4 GT4T111:47.084Drew Delmonico1:47.084Drew Delmonico1:47.467Drew Delmonico161.4Drew Delmonico29.150Drew Delmonico30.850Drew Delmonico46.316Drew Delmonico
Swift Db6FF21:49.259Edward Erlandson1:55.247Johnnie Crean1:54.993Johnnie Crean124.5Johnnie Crean31.358Johnnie Crean32.841Johnnie Crean47.766Edward Erlandson
Mazda RX-3STU11:50.913Tony Rivera1:50.913Tony Rivera1:52.737Tony Rivera135.2Tony Rivera30.415Tony Rivera32.456Tony Rivera47.999Tony Rivera
Honda S2000FF/STU21:51.118Eric Poulsen1:52.044Eric Poulsen1:51.118Eric Poulsen134.8Rylan Hazelton30.276Eric Poulsen31.650Eric Poulsen48.818Eric Poulsen
Mazda MiataSTU11:51.602Whitfield Gregg2:02.264Whitfield Gregg2:01.538Whitfield Gregg116.3Whitfield Gregg30.652Whitfield Gregg32.263Whitfield Gregg48.687Whitfield Gregg
SWIFT DB-FF11:53.098Edward Erlandson1:53.098Edward Erlandson1:54.741Edward Erlandson133.7Edward Erlandson30.951Edward Erlandson32.299Edward Erlandson49.791Edward Erlandson
BMW 330STU11:56.492Sean Lovett1:56.492Sean Lovett1:57.049Sean Lovett133.7Sean Lovett31.816Sean Lovett33.669Sean Lovett50.941Sean Lovett
Pontiac GTOT111:59.123Ed Gless1:59.760Ed Gless1:59.123Ed Gless120.7Ed Gless32.383Ed Gless34.587Ed Gless51.370Ed Gless
Nissan 300ZXSTU11:59.183James Slechta1:59.183James Slechta2:00.458James Slechta132.0James Slechta32.882James Slechta34.528James Slechta51.773James Slechta
Ford MustangT111:59.261Pratt Cole1:59.261Pratt Cole98.6Pratt Cole32.624Pratt Cole34.661Pratt Cole51.577Pratt Cole
Mazda MX-5STU21:59.707Oscar Jackson2:04.115Dale Shoemaker1:59.707Oscar Jackson125.9Dale Shoemaker32.339Oscar Jackson34.219Oscar Jackson52.330Oscar Jackson
Mazda RX-7STU12:00.248Michael Lewis2:00.248Michael Lewis130.4Michael Lewis32.729Michael Lewis34.570Michael Lewis52.880Michael 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.

Rule changes between these events

Cal Club 2023 → Cal Club 2024 2023-02-24 to 2024-02-23

T1 Sequential Gearbox Limitations in T1

#33691 from David Mead · Rule change · TB 23-03 (2023-03 Fastrack)

neutralT1 cars with aftermarket sequential transmissions get 10-inch max bellhousing; non-sequential cars gain 100 lbs weight break.

In GCR, Section 9.1.9.1.I.4., change as follows:
"Aftermarket sequential transmissions are permitted. Cars with aftermarket sequential shift transmissions shall utilize a 1:1 (or
greater/overdriven) ratio in top gear. Transmission location must be OEM. Maximum bellhousing length is 10 inches. Cars that
don’t use an aftermarket sequential transmission may decrease their competition weight by 100 lbs."

STU E&O STU NA Weight Chart.

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

fasterSTU minimum weight chart updated: 2450cc to 2595lbs, 2600cc to 2710lbs.

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"

FF Add Fast Forward Part Numbers for Honda Fit Engine

#33752 from Formula/Sports Racing Committee · Rule change · TB 23-03 (2023-03 Fastrack)

neutralFF Honda Fit engine adds Fast Forward part number alternatives for intake, exhaust, oil system, and scavenge pump components.

In FC/FF, GCR section 9.1.1.B.14.a.6, change as follows:
"For all Honda part numbers in these specifications, superc seding part numbers are considered equivalent.
In FC/FF, GCR section 9.1.1.B.14.f.5, change as follows:
"Cylinder head breather restrictor must be used as supplied by HPD or Fast Forward, unmodified.: HPD PN: 15262-F21S-A200; Fast
Forward PN: FF200-503."
In FC/FF, GCR section 9.1.1.B.14.k.2, change as follows:
"The upper manifold, air box and throttle body assembly must be used as delivered from Honda, HPD, or Fast Forward as noted
below."

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In FC/FF, GCR section 9.1.1.B.14.k.2, insert as follows:
"a. Intake manifold: HPD PN: 17210-F21S-A210; Fast Forward PN: FF200-201.
b. Throttle body: Honda Fit: PN: 16400ZZ5024; HPD PN: 16400ZZ5024; Fast Forward PN: FF200-104.
c. Throttle lever: HPD PN: 17330-F21S-A210; Fast Forward PN: FF200-101."
In FC/FF, GCR section 9.1.1.B.14.k.3, change as follows:
"All gaskets and sensors utilized on the inlet manifold from head to throttle body must be Honda Fit OEM, or HPD supplied or Fast
Forward as noted below.
a. Gasket In. manifold: HPD PN: 17105-RB0-004, Honda Fit OEM.
b. Gasket, EGR chamber cover: HPD PN: 17146-RB0-004, Honda Fit OEM.
c. Gasket In. port: HPD PN: 17115-RB0-007, Honda Fit OEM.
d. Gasket, restrictor: HPD PN: 17399-F21S-A200, (2 required) HPD; Fast Forward PN: FF200-109. Two required."
In FC/FF, GCR section 9.1.1.B.14.k.5, change as follows:
"The Honda Fit engine is required to have an HPD supplied air inlet restrictor supplied by HPD or Fast Forward: HPD PN: 17344-
F21S-A201; Fast Forward PN: FF200-110, with internal diameter of 30.5mm and thickness of 3.175mm (0.125 inches) correctly
installed within the intake system."
In FC/FF, GCR section 9.1.1.B.14.m.1, change as follows:
"The exhaust manifold must be as supplied by HPD or Fast Forward:, HPD part # PN: 18150-F21S-A200 or # PN: 1818 50-F21S-B200;
Fast Forward PN: FF500-001 or PN: FF500-002."
In FC/FF, GCR section 9.1.1.B.14.n.1, change as follows:
"The oil pan, baffle plate, and scavenge pump filter fittings must be as supplied by HP or Fast Forward as noted below. No
modifications are permitted.
a. Oil pan: HPD PN: 11200-F21S-A210 or PN: 11200-F21S-C240; Fast Forward PN: FF100-201A or PN: FF100-201B.
b. Oil pan baffle plate: HPD PN: 11221-F21S-A210; Fast Forward PN: FF100-202.
c. Oil scavenge pump filter fittings (2 required): HPD PN: 15180-F21S-A210; Fast Forward PN: FF100-204."
In FC/FF, GCR section 9.1.1.B.14.n.3, change as follows:
"The scavenge pump and internal scavenge pump parts must be as supplied from HPD or Fast Forward as noted below."
In FC/FF, GCR section 9.1.1.B.14.n.3, change as follows:
"b. Rotor outside diameter: HPD 44.400mm (1.748 inches):; Fast Forward 40.640mm (1.600 inches).
c. Scavenge pump rotor set: HPD PN: 15450-F21S-A20; Fast Forward PN: FF100-110.
d. Oil pump: HPD PN: 15100-F21S-A200; Fast Forward PN: FF100-100A.
e. Scavenge pump cartridge: 15111-F21S-A21; Fast Forward PN: FF100-127.
f. Scavenge pump port A: HPD PN: 15137-F21S-A20; Fast Forward PN: FF100-101.
g. Scavenge pump port B: HPD PN: 15139-F21S-A20; Fast Forward PN: FF100-102.
h. Scavenge pump shaft: HPD PN: 15510-F21S-A20; Fast Forward PN: FF100-103.
i. Scavenge pump front cover: HPD PN: 15070-F21S-A21; Fast Forward PN: FF100-104."

T1 T1 GT4 adjustments

#33786 from Touring Committee · Rule change · TB 23-03 (2023-03 Fastrack)

fasterT1 GT4 all nine cars lose 125 lbs minimum weight with driver, from 3200–3575 to 3075–3450.

In Touring 1 - GT4 Spec Lines, change Min. Weight with Driver (LBS) as follows:
Aston Martin Vantage AMR GT4: "3575 3450"
Audi R8 GT4: "3550 3425"
BMW M4 GT4: "3500 3375"
Ford Mustang GT4: "3550 3425"
Maclaren 570S GT4: "3450 3325"
Mercedes AMG GT4: "3450 3325"
Porsche 718 Cayman GT4 CS MR: "3200 3075"

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Porsche 718 GT4 RS Clubsport: "3450 3325"
Toyota Supra GR GT4: "3350 3225"

T1 Sunset of pre 2023 Touring 1 Rules.

#33916 from Touring Committee · Rule change · TB 23-03 (2023-03 Fastrack)

neutralT1 removes GCR Section 9.1.9.1.A. and T1 Spec Lines entirely, sunsetting pre-2023 Touring 1 rules.

In T1, GCR Section 9.1.9.1.A., remove in its entirety.
In T1 Spec Lines, remove in its entirety.

T1 Clarification for Camaro Gen5 2010-2015

#33739 from Clark Nunes · Rule change · TB 23-04 (2023-04 Fastrack)

slowerT1 Chevrolet Camaro Gen5 LS3-6160 adds 70mm flat plate restrictor, weight 3550 lbs.

In T1 Spec Lines, Chevrolet Camaro Gen 5 ('10-'15) Including SS, Z28, classify Spec Line Number 1135 as follows:

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

STU Alternate OEM Miata Intake Manifold

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

neutralSTU Mazda BP5A classified at 1839 cc maximum displacement, 2023-04-01.

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.

T1 T1 GT4 adjustments

#33786 from Touring Committee · Rule change · TB 23-05 (2023-05 Fastrack)

neutralT1 GT4 weights clarified for nine cars, ranging from 3200 lbs Porsche 718 Cayman to 3575 lbs Aston Martin.

RM 23-04 – Touring 1 weights dated 3/21/2023
As an E&O to the February Fastrack, in T1-GT4 leave weights as follows:
Aston Martin Vantage AMR GT4: 3575
Audi R8 GT4: 3550
BMW M4 GT4: 3500
Ford Mustang GT4: 3550
Maclaren 570S GT4: 3450
Mercedes AMG GT4: 3450

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Porsche 718 Cayman GT4 CS MR: 3200
Porsche 718 GT4 RS Clubsport: 3450
Toyota Supra GR GT4: 3350

FA E&O - Correct Pro Formula Mazda spec line dimensional equivalent

#34085 from Club Racing Board · Rule change · TB 23-05 (2023-05 Fastrack)

fasterFA Pro Formula Mazda maximum bodywork width behind front wheels increases to 51.97 inches.

In FA Table 2, Pro Formula Mazda spec line, change as follows:
"The overall maximum width of the bodywork behind the front wheels shall not exceed 132cm (51.17 51.97 inches)."

FA Add new spec line for MSR Formula Mazda FMzR to Table 2

#34139 from Club Racing Board · Rule change · TB 23-05 (2023-05 Fastrack)

neutralFA MSR Formula Mazda FMzR added to Table 2 classification.

RM 23-06 – MSR - FMzR Formula Atlantic Classification dated 4/21/2023
In FA Table 2, add a spec line as follows:

T1 Touring 1 Tire Sizes

#34191 from Club Racing Board · Rule change · TB 23-05 (2023-05 Fastrack)

fasterT1-GT4 McLaren 570S and Mercedes AMG GT4 front tires widen to 315 mm.

RM 23-05 – Touring 1 Tire Sizes dated 3/21/2023
In T1-GT4 change tire sizes as follows:
Maclaren 570S GT4 (f)285 315
(r)315
Mercedes AMG GT4 (f)275 315
(r)315

T1 Request to reinstate T1 S197 Mustang

#34048 from David Mead · Rule change · TB 23-06 (2023-05 Fastrack)

neutralT1 Ford Mustang S197 (05-14) reinstated with 3550 lbs minimum weight, 75mm restrictor, Voodoo engine permitted.

In T1 Spec Lines, classify Ford Mustang S197 (05-14) Includes GT, Boss302, 302S, 302R, FR500C, FR500S as follows:

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

Applies to Ford Mustang on this page: Pratt Cole

FA Simplify Pro Formula Mazda wheel allowance

#34190 from Club Racing Board · Rule change · TB 23-06 (2023-06 Fastrack)

unclearFA Pro Formula Mazda front wheels widen to 10 in. max; rear wheels narrow to 14 in. min.

In FA, Pro Formula Mazda spec line, change wheel width as follows:
"Pro Mazda series wheels

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

T1 Gen 5 Camaro Engine

#33875 from Matt Spicuzzi · Rule change · TB 23-06 (2023-07 Fastrack)

neutralT1 Chevrolet Camaro Gen 5 LS7 gets two spec lines: 1131 with 70mm restrictor, 1136 with 53mm restrictor, both 3450 lbs minimum.

In T1-NEW Spec Lines, Chevrolet Camaro Gen 5 (10-15) Including SS, Z28, classify Spec Line Number 1131 and 1136 as follows:

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

T1 Inquiry to letter #33682

#34071 from Andrew Aquilante · Rule change · TB 23-06 (2023-07 Fastrack)

slowerT1 Chevrolet Camaro Gen 5, Corvette C5 and C6: engine resleeve restricted to stock parameters only, no longer LS3 bore/stroke.

In T1 NEW Spec Lines, Chevrolet Camaro Gen 5 (10-15) Including SS, Z28, change Engine Notes as follows:
1130: "May resleeve any LS block to LS3 bore/ stroke for Engine replacement. May resleeve to stock parameters for engine repair
or replacement."
1135: "May resleeve any LS block to LS3 bore/ stroke for Engine replacement.May resleeve to stock parameters for engine repair
or replacement."
In T1 NEW Spec Lines, Chevrolet Corvette C5 (‘97-’04) – Includes: Z06, Coupe, Convertible, change Engine Notes as follows:
1132: "May resleeve any LS block to LS3 bore/ stroke for Engine replacement. May resleeve to stock parameters for engine repair
or replacement."

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1134: "May resleeve any LS block to LS3 bore/ stroke for Engine replacement. May resleeve to stock parameters for engine repair
or replacement."
1136: "May resleeve any LS block to LS3 bore/ stroke for Engine replacement. May resleeve to stock parameters for engine repair
or replacement."
1138: "May resleeve any LS block to LS3 bore/ stroke for Engine replacement. May resleeve to stock parameters for engine repair
or replacement."
In T1 NEW Spec Lines, Chevrolet Corvette C6 (05-13) - Includes Z51, GrandSport, Z06, Z06 Carbon, change Engine Notes as
follows:
1150: "May resleeve any LS block to LS3 bore/ stroke for Engine replacement. May resleeve to stock parameters for engine repair
or replacement."
1160: "May resleeve any LS block to LS3 bore/ stroke for Engine replacement. May resleeve to stock parameters for engine repair
or replacement."
1170: "May resleeve any LS block to LS3 bore/ stroke for Engine replacement. May resleeve to stock parameters for engine repair
or replacement."
1180: "May resleeve any LS block to LS3 bore/ stroke for Engine replacement. May resleeve to stock parameters for engine repair
or replacement."
1190: "May resleeve any LS block to LS3 bore/ stroke for Engine replacement. May resleeve to stock parameters for engine repair
or replacement."

T1 Viper Cleanup

#34107 from Scotty B White · Rule change · TB 23-06 (2023-05 Fastrack)

fasterT1 Dodge Viper ACR/ACR-X restrictor increases from 50mm to 60mm flat plate.

In T1 NEW Spec Lines, Dodge Viper ACR/ACR-X Spec Line 1360, change Required Restrictor as follows:
"50mm 60mm flat plate"

T1 Viper 8300 OEM FPR Size

#34268 from Scotty B White · Rule change · TB 23-06 (2023-05 Fastrack)

unclearT1 Dodge Viper ACR/ACR-X: Spec Line 1370 restrictor increases to 55mm, Line 1390 decreases to 55mm.

In T1 NEW Spec Lines, Dodge Viper ACR/ACR-X Spec Line 1370, change Required Restrictor as follows:
"(2) 47mm 55mm flat plates"
In T1 NEW Spec Lines, Dodge Viper ACR/ACR-X Spec Line 1390, change Required Restrictor as follows:
"(2) 60mm 55mm flat plates"

STU 2022 Toyota GR Cup for STU

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

neutralToyota GR Cup and GR86 Cup (2022-) newly classified in STU at 2700 lbs with 2387 cc engine.

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

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

T1 Ford Mustang S197 (05-14) Clarification

#34450 from Club Racing Board · Rule change · TB 23-06 (2023-05 Fastrack)

neutralT1 Ford Mustang S197 05-14 now requires OEM 8.8 differential housing.

In T1-NEW Spec lines, Ford Mustang S197 (05-14) Includes GT, Boss302, 302S, 302R, FR500C, FR500S, change Notes as follows:
"OEM 8.8 Differential Housing"

T1 C5 Approved Aero That Was Mistakenly Deleted

#34374 from Joe Aquilante · Rule change · TB 23-08 (2023-08 Fastrack)

fasterT1 Corvette C5 gains approved aero parts: carbon rear spoiler, vented front splitter, side skirts, with 50 lb weight reduction allowed.

In T1 NEW Spec Lines, Chevrolet Corvette C5 (‘97-’04) – Includes: Z06, Coupe, Convertible, Spec Lines 1132-1138, add to Notes
as follows:
"Any option of OEM Bodywork parts may be used as basis for aero measurements. Rear spoiler max 5” Above bumper allowed.
+50lbs. The following parts are permitted, with a 50lb decrease from base weight, in lieu of the aero options permitted in
9.1.9.1.B: (C7Carbon Rear- Spoiler CCC5 EX- RSB-GB, Vented Front Splitter CCC5-FS-GB, Side Skirts CCC5 SS-GB.)"

T1 Why no Camaro?

#34421 from Scotty B White · Rule change · TB 23-08 (2023-05 Fastrack)

neutralChevrolet Camaro GT4-R classified in T1 GT4 Spec Line 4035, minimum weight 3375 lbs, 315 max tire, 63mm restrictor, ineligible for Runoffs.

In T1 GT4 Spec Lines, classify Chevrolet Camaro GT4-R as follows:

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

T1 Request to Remove Expiration from T1 spec lines #1350 & #1370

#34470 from Scotty B White · Rule change · TB 23-08 (2023-05 Fastrack)

neutralT1 Dodge Viper ACR / SRT RT-10 and ACR/ACR-X spec lines 1350 and 1370 remove 12/23 expiration.

In T1 NEW Spec Lines, Dodge Viper ACR / SRT RT-10, change Spec Line Number as follows:
"1350 *Spec line Expires 12/23*"
In T1 NEW Spec Lines, Dodge Viper ACR/ACR-X, change Spec Line Number as follows:
"1370 *Spec line Expires 12/23*"

T1 Remove

#34475 from Touring Committee · Rule change · TB 23-08 (2023-05 Fastrack)

neutralT1 GT4 McLaren 570S, Mercedes AMG GT4, and Porsche 718 Cayman GT4 CS MR now eligible for Runoffs competition.

In T1 GT4 Spec Lines, Maclaren 570S GT4, Spec Line Number 4050, remove Notes as follows:
"**NOT YET ELLIGIBLE FOR RUNOFFS COMPETITION (Q.2)**"
In T1 GT4 Spec Lines, Mercedes AMG GT4, Spec Line Number 4060, remove Notes as follows:
"**NOT YET ELLIGIBLE FOR RUNOFFS COMPETITION (Q.2)**"
T1 GT4 Spec Lines, Porsche 718 Cayman GT4 CS MR, Spec Line Number 4070, remove Notes as follows:
"**NOT YET ELLIGIBLE FOR RUNOFFS COMPETITION (Q.2)**"

T1 Error in T1 GT4 numbering scheme-

#34578 from Touring Committee · Rule change · TB 23-08 (2023-05 Fastrack)

neutralT1 GT4 BMW M4 Spec Line Number changed from 4050 to 4030.

In T1 GT4 Spec Lines, BMW M4, change Spec Line Number as follows:
"4050 4030"

T1 New T1 add spec line for C5 corvette LS2 engines (Copy from C6)

#33764 from Craig Anderson · Rule change · TB 23-12 (2023-09 Fastrack)

neutralT1 Chevrolet Corvette C5 LS2 added with 6000cc displacement, 3300 lbs minimum weight, 72mm flat plate restrictor.

In T1 Spec Lines, classify Chevrolet Corvette C5 (‘97-’04) – Includes: Z06, Coupe, Convertible as follows:

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

T1 2004 - 2006 Pontiac GTO Re-Integration Back Into T1

#34403 from Ed Gless · Rule change · TB 23-12 (2023-12 Fastrack)

neutralPontiac GTO 2006-2009 re-integrated into T1 with LS2 at 3400 lbs, 72mm restrictor, and LS3 at 3500 lbs, 61mm restrictor.

In T1 Spec Lines, classify Pontiac GTO 2006-2009 as follows:

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

Applies to Pontiac GTO on this page: Ed Gless

T1 Request to Classify Porsche 997-1 GT3 Cup

#34561 from Scotty B White · Rule change · TB 23-12 (2023-12 Fastrack)

neutralT1 Porsche 997-1 GT3 Cup added at spec line 4210, minimum weight 3050 lbs.

In T1 Spec Lines, delete the Porsche 996 GT3 Cup car from the standard spec lines and classify "Homologated car" section as
follows:
T1 – Homologated Cars

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

T1 C7 Corvette Rule Change Request

#34897 from Heath Karl · Rule change · TB 23-12 (2023-09 Fastrack)

neutralT1 Chevrolet Corvette C7 (14-19) including Z51, Grandsport newly classified as homologated car.

In T1 Spec Lines, classify Chevrolet Corvette C7 (14 - 19) - Includes Z51, Grandsport as follows:
T1 – Homologated Cars

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

T1 Camaro Gen 5 Weight Reduction Due to Competitive Disadvantage

#35092 from Clark Nunes · Rule change · TB 23-12 (2023-09 Fastrack)

fasterT1 Gen 5 Camaro minimum weight drops 75 lbs to 3475; restrictor increases 70mm to 75mm.

In T1 Spec Lines, Gen 5 Camaro, change as follows:
Spec Line 1130 - Minimum Weight "3550 3475"
Spec Line 1135 - Minimum Weight "3550 3475"
Restrictor Required "70mm 75mm-Flat Plate"

T1 Addendum to Letter #35022: Drivetrain Rule

#35105 from Clyde Greene · Rule change · TB 23-12 (2023-09 Fastrack)

neutralT1 Aston Martin Vantage permitted to use OEM Sportshift II transmission.

In T1 Spec Lines, Aston Martin Vantage, add to Chassis Notes as follows:
"OEM Sportshift II transmission permitted."

T1 GT4 batch adjustment in T1

#35162 from Touring Committee · Rule change · TB 24-01 (2024-01 Fastrack)

unclearT1-GT4 batch adjustments: five cars lighter, two heavier, restrictors and ECU maps changed, five models now eligible for Runoffs.

In GCR, Section 9.1.9.1.A.T., change as follows:
"Tires- Tires must conform to GCR section 9.3.TIRES and als o must conform to spec line requirements. DOT approved tires are
permitted. Slicks conforming to the spec line are permitted."
In Touring 1 - Homologated Cars Spec Lines, 4100- BMW M2 ClubSport Racing, change Must Conform To as follows:
"Tires conforming to SRO TCX rules allowed. Must meet factory specs."
In Touring 1 - Homologated Cars Spec Lines, 4120- Ford Mustang FP350S 2017, change as follows:
Must Conform To: "Tires conforming to Trans Am SGT tire rules allowed Must meet factory specs."
Chassis Notes: "VIN not required. Additional permitted allowances: DOT tires required. Other consumables are open, alternate

Show 40 more lines

driveshaft permitted, aftermarket wheels and fuel cell per Touring category rules permitted. Shocks conforming to T1 rules
permitted. Alternative rear toe links permitted."
In T1-GT4 Spec Lines, change Chassis Notes as follows:
Aston Martin Vantage AMR GT4: "**NOT YET ELLIGIBLE FOR RUNOFFS COMPETITION (Q.2)** Slick tires conforming to IMSA GT4
or SRO GT4 specs are permitted."
Audi R8 GT4: "**NOT YET ELLIGIBLE FOR RUNOFFS COMPETITION (Q.2)**Slick tires conforming to IMSA GT4 or SRO GT4 specs
are permitted."
BMW M4 GT4: "**NOT YET ELLIGIBLE FOR RUNOFFS COMPETITION (Q.2)**Slick tires conforming to IMSA GT4 or SRO GT4 specs
are permitted."
Chevrolet Camaro GT4-R: "**NOT YET ELLIGIBLE FOR RUNOFFS COMPETITION (Q.2)**Slick tires conforming to IMSA GT4 or SRO
GT4 specs are permitted."
Ford Mustang GT4: "**NOT YET ELLIGIBLE FOR RUNOFFS COMPETITION (Q.2)**Slick tires conforming to IMSA GT4 or SRO GT4
specs are permitted."
Maclaren 570S GT4: "Slick tires conforming to IMSA GT4 or SRO GT4 specs are permitted."
Mercedes AMG GT4: "Slick tires conforming to IMSA GT4 or SRO GT4 specs are permitted."
Porsche 718 Cayman GT4 CS MR: "Slick tires conforming to IMSA GT4 or SRO GT4 specs are permitted."
Porsche 718 GT4 RS Club-sport: "Slick tires conforming to IMSA GT4 or SRO GT4 specs are permitted."
Toyota Supra GR GT4: "**NOT YET ELLIGIBLE FOR RUNOFFS COMPETITION (Q.2)**Slick tires conforming to IMSA GT4 or SRO GT4
specs are permitted."
In T1-GT4 Spec Lines, change as follows:
Aston Martin Vantage AMR GT4:
Weight: “3575 3490”
Performance Control: “SRO power level ECU Map 3 IMSA Map id 11”
Chevrolet Camaro GT4-R:
Weight: “3375 3435”
Performance Control: “63 62mm”
Ford Mustang GT4:
Weight: “3550 3535”
Performance Control: “63 71mm SRO compliant restrictor IMSA ECU Cal”
Maclaren 570S GT4:
Weight: “3450 3250”
Performance Control: “SRO 2019 BOP ECU map SRO Rest 1”
Mercedes AMG GT4:
Weight: “3450 3470”
Performance Control: “Power level 2 map 5”
Porsche 718 Cayman GT4 CS MR:
Weight: “3200 3250”
Performance Control: “54 53.7mm”
Toyota Supra GR GT4:
Weight: “3350 3315”

T1 Remove T1 spec lines

#35192 from Touring Committee · Rule change · TB 24-01 (2024-01 Fastrack)

neutralT1 spec lines 1000, 1010, 1020, 1040, 1360, 1400–1410, 1520–1680, 1700–1720 deleted entirely.

In T1 Spec Lines, delete the following spec line numbers in their entirety:

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

FF Honda Fit Oversize Piston Rings

#35305 from Doug Learned · Rule change · TB 24-01 (2024-01 Fastrack)

neutralFF Honda Fit gains Fast Forward FF800-100 oversize piston ring pack option.

In FF, GCR section 9.1.1.B.14.e.3.a, add the following:
"The standard ring pack, PN 13011-RB1-004 (Riken) or 13011-RB1-006 (Nippon), or the oversize ring pack, PN 13021-RB7-Z01
(Riken), or 13021-RB7-Z02 (Nippon), or FF800-100 (Fast Forward), may be used."

STU ST Electric-Assisted Steering Systems

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

neutralSTL and STU power steering rules clarified to permit electric-assisted and hydraulic-assisted steering systems.

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"

T1 C8 Corvette T1 Restrictor Plate Request

#35213 from Garry Crook · Rule change · TB 24-02 (2024-02 Fastrack)

fasterC8 Corvette T1 restrictor plate increases from 70mm to 72mm flat plate.

In T1 NEW Spec Lines, Chevrolet Corvette C8 (20- 23) - Includes Z51, #1210, change Required Restrictor as follows:
"70mm 72mm - Flat Plate"

T1 The Cars Have Expired

#35379 from Touring Committee · Rule change · TB 24-02 (2024-02 Fastrack)

neutralT1 NEW class removes 23 spec lines including Acura NSX, Ferrari, Porsche 996, Nissan Z cars, and others; Porsche 997 spec line 1680 expiration removed.

In GCR Contents, change as follows:
"9.1.9.1 TOURING (T1) CATEGORY NEW
T1 NEW"
In GCR, Section 9.1.9.1.Touring (T1) NEW Category Specifications, change as follows:
"9.1.9.1.Touring (T1) NEW Category Specifications"
In T1 NEW Spec Lines, change as follows:
"9.1.9.1.A T1 NEW Spec Lines"
"T1 NEW"

Show 26 more lines

In T1 NEW Spec Lines, delete the following Spec Lines in their entirety:
"Acura NSX (Spec Line 1000)
Acura NSX Turbo (Spec Line 1010)
Acura NSX Turbo World Challenge (Spec Line 1020)
Audi TTRS (GTS 2011 Spec) (Spec Line 1040)
Dodge Viper ACR/ACR-X (Spec Line 1360)
Ferrari 360 (Spec Line 1400)
Ferrari 430 (Spec Line 1410)
Ferrari 430 Challenge (Spec Line 1420)
Mazda MX-5 (06-15) (Spec Line 1520 and 1530)
Mazda RX-7 (Spec Line 1540)
Nissan GTR (Spec Line 1550)
Nissan 350/370Z (Spec Line 1560)
Nissan 370Z Supercharged (Spec Line 1570)
Nissan 350Z (Spec Line 1580)
Nissan 350Z/370Z (Spec Line 1590)
Porsche Cayman/S/GTS (05-15) (Spec Line 1600, 1610 and 1620)
Porsche Cayman GTS (2011) (Spec Line 1630)
Porsche 928 S4 Porsche 928 GTS-R (Spec Line 1640)
Porsche 996 (Spec Line 1650)
Porsche 996 TT OEM (Spec Line 1660)
Subaru WRX, WRX STI (05-2020) (Spec Line 1700)
Toyota Celica All-Trac (Spec Line 1710)
Toyota Supra MK4 (Spec Line 1720)"
In T1 NEW Spec Lines, Porsche 997, change Spec Line Number as follows:
"1680 *Spec line Expires 12/23*"

Cal Club 2024 → Cal Club 2025 2024-02-23 to 2025-02-22

T1 9.1.9.1 T1 new category item/ line 26 rule to expire Jan 1 2023

#35411 from Geoffrey Hegel · Rule change · TB 24-03 (2024-03 Fastrack)

neutralPontiac GTO 2006-2009 LS1 added to T1 as Spec Line 1590, 5700 cc, 3400 lbs minimum.

In T1 Spec Lines, classify Pontiac GTO 2006-2009 as Spec Line Number 1590 as follows:

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

STU Letter #35397 addendum

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

neutralSTU Mini Cooper S SC: alternate LEAP OMICRON hood scoop LEP-OMICRON3 permitted.

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."

STU S54 Drysump

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

neutralSTU BMW S54 B32 OEM now permits dry sump oiling system.

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

T1 Honda S2000

#35582 from Touring Committee · Rule change · TB 24-04 (2024-04 Fastrack)

neutralT1 Honda S2000 classified with 2400 lb minimum weight, 2950 cc displacement, 4.75" supercharger pulley.

In T1 Spec Lines, classify Honda S2000 as follows:

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

T1 Please Expedite classing the C63 Mercedes

#35987 from Touring Committee · Rule change · TB 24-05 (2024-05 Fastrack)

neutralMercedes AMG-C63 S (2023) classified in T1 with 4000 lbs minimum weight and 3700 restrictor.

In T1 Spec Lines, classify Mercedes AMG-C63 S (2023) as follows:

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

STU RWD Turbo Disadvantage

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

fasterSTU RWD turbo cars no longer required to reduce restrictor by 1 mm from table.

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"

FF Update to FF EGR Blanking Plate Rule

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

neutralFF VTEC activation valve must function; EGR blanking plate rule clarified with Fast Forward part numbers.

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."

FF Change FF/FC Weight with Sequential Gearbox

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

fasterFF and FC cars with sequential gearbox must add 10 lbs. to minimum weight, down from 25 lbs.

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."

STU R53 15% Pulley Request

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

slowerSTU Mini Cooper S SC 1900 restricts to 2.565 diameter pulley; 2100 allows 2.285 diameter pulley.

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."

FF Alternative Oversize Honda Fit Pistons

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

neutralFF Honda Fit allows Fast Forward 0.25mm oversize pistons PN FF800-110 as alternative; piston diameter spec clarified to 2.8835 inches.

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).

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d. Minimum weight: 198.0 grams (6.984 ounces).
e. Minimum weight of piston pin: 66 grams (2.25 ounces).
f. Combined minimum weight of piston, piston pin and connecting rod: 543.5 grams (18.85 ounces).
g. Combined minimum weight of piston, wrist pin, and circlips: 267 grams (9.418 ounces).
h. Centerline of wrist pin to crown edge: 26.289mm (1.035 inches).
i. Ring groove widths:
Top ring groove: 1.003mm (0.0395 inches).
Middle ring groove: 1.016mm (0.0400 inches).
Oil ring groove: 1.981mm (0.0780 inches).
j. Ring groove distance from wrist pin center to bottom of groove:
Top ring groove: 19.63mm (0.7730 inches).
Middle ring groove: 15.29mm (0.6020 inches).
Oil ring groove: 10.91mm (0.4295 inches)."

T1 Changes to T1 Tires for GT4 and Other Cars

#35383 from Andrew Aquilante · Rule change · TB 24-12 (2024-12 Fastrack)

unclearT1 GT4 tire sizes adjusted across ten cars: most non-DOT rear to 305/660, Audi and McLaren 305/645, Camaro and Mustang 305/680.

In T1 GT4 Spec Lines, change Tire Size as follows:
Aston Martin Vantage AMR GT4 4010: "315 DOT, 305/660 Non-DOT"
Audi R8 GT4 - Spec Line #4020: "315 DOT, 305/645 Non-DOT"
BMW M4 GT4 - Spec Line #4030: "315 DOT, 305/660 Non-DOT"
Chevrolet Camaro GT4-R- Spec Line #4035: "315 DOT, 305/680 Non-DOT"
Ford Mustang GT4 - Spec Line #4040: "315 DOT, 315/680 Non-DOT"
Mclaren 570S GT4 - Spec Line #4050: "315 DOT, 305/645 Non-DOT"
Mercedes AMG GT4 - Spec Line #4060: "315 DOT, 305/660 Non-DOT"

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Porsche 718 Cayman GT4 CS MR - Spec Line #4070: "315 DOT, 305/660 Non-DOT"
Porsche 718 GT4 RS Clubsport - Spec Line #4080: "315 DOT, 305/660 Non-DOT"
Toyota Supra GR GT4 - Spec Line #4090: "315 DOT, 305/660 Non-DOT"

T1 G82 M4 GT4 inclusion in T1

#35864 from Denny Stripling · Rule change · TB 24-12 (2024-12 Fastrack)

neutralBMW M4 GT4 (G82) added to T1 GT4 at 3525 lbs minimum weight with Red power stick control.

In T1 GT4 Spec Lines, SL#4030, change as follows:
Model: "BMW M4 GT4 (F82)"
Performance Control: "Gold power stick Red power stick"
In T1 GT4 Spec Lines, classify BMW M4 GT4 (G82) as follows:

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

T1 Alt. Clutch Allowance

#36606 from Hugh Stewart · Rule change · TB 24-12 (2024-12 Fastrack)

neutralT1 Spec Lines now permits 5.5 inch clutch in Engine Notes.

In T1 Spec Lines, SL# 1050, change add to Engine Notes the following:
"5.5 inch clutch permitted."

T1 BOP Changes Need Updates

#36667 from Joe Rainey · Rule change · TB 24-12 (2024-12 Fastrack)

fasterT1 GT4 Spec Line 4020 restrictor opens from 44mm to 45mm, minimum weight drops to 3400 lbs.

In T1 GT4 Spec Lines, Spec Line 4020, change as follows:
Performance Control: Power level 2020, 44mm 45mm SRO compliant restrictor"
Min. Weight with driver (LBS): "3550 3400"

T1 Request Ford Performance Darkhorse R in T1

#37136 from Christopher Childs · Rule change · TB 24-12 (2024-12 Fastrack)

neutralMustang Darkhorse R added to T1 homologated cars at 3,250 lbs minimum with 305/315 tires, ineligible for Runoffs until 3 Super Tour events.

In T1-Homologated Cars Spec Line, classify Mustang Darkhorse R (Mustang Challenge) as follows:
T1 – Homologated Cars

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

STU Request to Remove Miata Hubs from General category

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

neutralSTL/STU: 90-05 Mazda Miata alternate front wheel hubs moved from General to specific part approval.

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."

STU BMW N54/N55 Engine Allowance

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

slowerSTU BMW N54/N55 turbo inlet restrictors now required per GCR definition; turbo swapping prohibited.

"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.

T1 Car Mods for T1 Corvette under line item 1150

#37173 from Thomas Napolitano · Rule change · TB 24-12 (2024-12 Fastrack)

neutralT1 Corvette may roll or flatten wheel opening lips for tire clearance; plastic fenders may remove lips if edge thickness matches basic material.

In GCR, Section 9.1.9.1.A.2,, add the following:
"It is permitted to roll under or flatten any interior lip on the wheel opening for tire clearance. Cars with plastic/composite
fenders may remove any interior wheel opening lip, but the resulting material edge shall be no thinner than the basic fender
material thickness. Non-metallic inner fender liners may be removed. Vents may be added to fenders."

T1 Increased Bore Throttle Bodies for E46 M3 S54 Engine

#37273 from Mark Pfeffer · Rule change · TB 24-12 (2024-12 Fastrack)

fasterT1 E46 M3 S54 can now use Dinan Throttle Body #D760-3400 on 3.250L engine.

In T1 Spec Lines, E46 M3 Spec Line # 1050, add to Engine Notes the following:
"Dinan Throttle Body #D760-3400 allowed on the 3.250L."

STU Audi 1.8t Wagon STU Table B

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

fasterSTU Audi 1.8T wagon deleted; Porsche 944 1800 weight to Chart, turbo inlet restrictor removed.

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."

STU Merger GT3 to STU

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

neutralSTU-GT3 reclassified as STU-GT3U effective January 1, 2026.

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

STU GT3 TCR Tire allowance

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

slowerSTU GT3 TCR gains 275-width tire option with 100 lb weight penalty, but not in A compound.

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."

T1 T1 Parity Compared to GT4

#37170 from Tony Ave · Rule change · TB 25-02 (2025-02 Fastrack)

slowerT1 Mustang gains 125 lbs to 3600, restrictor shrinks 65mm to 60mm. Corvette gains 50 lbs to 3500, restrictor shrinks 70mm to 67mm. BMW deleted.

In T1 Spec Lines, change Weight and Restrictor Required as follows:
Mustang - Spec Line 1430
Weight: "3475 3600"
Restrictor Required: "65mm 60mm - FPR"
Corvette Spec Line 1190
Weight: "3450 3500"
Restrictor Required: "70mm 67mm - Flat Plate"
In T1 Spec Lines, delete Spec Line BMW # 1190 in its entirety.

T1 Clarification of Request Approval #37273

#37399 from Mark Pfeffer · Rule change · TB 25-02 (2025-02 Fastrack)

unclearT1 E46 M3 Spec Line 1050 allows VAC Motorsports throttle body VAC-TB-S54 on 3.250L engine instead of Dinan.

In T1 Spec Lines, E46 M3 Spec Line # 1050, change Engine Notes as follows:
"Dinan Throttle Body #D760-3400 VAC Motorsports #VAC-TB-S54 allowed on the 3.250L."

T1 C8 Corvette Facts

#37400 from Garry Crook · Rule change · TB 25-02 (2025-02 Fastrack)

fasterT1 Chevrolet Corvette C8 (2023-23) minimum weight reduced from 3600 lbs to 3500 lbs.

In T1 Spec Lines, Chevrolet Corvette C8 (20- 23) - Includes Z51, Spec Line # 1210, change Min. Weight as follows:
"3600 3500"

T1 Camaro Gen 5 Competitive Disadvantage

#37440 from Clark Nunes · Rule change · TB 25-02 (2025-02 Fastrack)

fasterT1 Chevrolet Camaro Gen 5 restrictor increases from 75mm to 80mm flat plate.

In T1 Spec Lines, Chevrolet Camaro Gen 5 (10-15) Including SS, Z28 Spec Line 1135, change Required Restrictor as follows:
"75mm 80mm - Flat Plate"

T1 Tire Changes in the Rules for GT4

#37497 from Joe Rainey · Rule change · TB 25-02 (2025-02 Fastrack)

unclearT1 Audi R8 GT4 Spec Line #4020 maximum tyre size changes to 315 DOT, 305/645, or 30/65-18 (f), 33/68-18 (r) Non-DOT.

In T1-GT4 Spec Lines, Audi R8 GT4 Spec Line #4020, change Max Tire Size as follows:
"315 DOT, 305/645, or 30/65-18 (f), 33/68-18 (r) Non-DOT"

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)

neutralFA adds Tatuus F.3 T-318 or FR-19 as spec line car in Table 2 for Formula Regional European Championship.

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.

Cal Club 2025 → Cal Club 2026 2025-02-22 to 2026-02-21

STU BMW N54/N55 Engine Allowance Follow Up

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

neutralSTU BMW N54/N55 3.0L classified at Chart +3% minimum weight; N54 twin turbo not allowed.

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

STU STU Mini Cooper pulley size clarification re: letter #36980

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

fasterSTU Mini Cooper S SC supercharger pulley diameter reduced from 2.285 to 2.185.

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

T1 Correct and make new T1 BOP adjustments.

#37737 from Touring Committee · Rule change · TB 25-03 (2025-03 Fastrack)

unclearT1 Mustang Spec 1430 restrictor opens 60mm to 65mm; Spec 1460 weight rises to 3500 lbs, restrictor 70mm; Corvette 1190 restrictor opens 67mm to 70mm; BMW 1090 restrictor narrows 40mm to 35mm; BMW 1100 weight rises to 3350 lbs.

In T1 Spec Lines, change Weight, Restrictor Required and/or Notes as follows:
Mustang - Spec Line 1430:
Restrictor Required: "60mm 65mm - FPR"
Mustang - Spec Line 1460:
Weight: "3425 3500"
Restrictor Required: "70mm - FPR"
Corvette Spec Line 1190:
Restrictor Required: "67mm 70mm - Flat Plate"

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BMW - Spec Line 1090:
Required Restrictor: "(2) X 40mm 35mm diameter hole inlet restrictor plate required"
Chassis Notes: "This spec line is set to expire 12/31/25."
BMW - Spec Line 1100:
Minimum Weight: "3150 3350”

STU Question About a Weight Modifier

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

fasterSTU Honda K20C1 Turbo I4 exempted from 3% DI weight adder in Spec Lines Table A.

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."

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)

fasterFF allows older cars with rocker arm or outboard suspension to use bias ply slicks or VFF tires instead of radials.

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

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Alternatively, Formula F cars with rocker arm suspension (e.g., Swift DB1, 1987-90 Reynard) and/or outboard suspension on at
least one chassis end may use the following tires:
Dries:
Front - Hoosier H43130 R60A 20.0 x 6.0-13 or H43164 R60A 20.5 x 7.0-13 bias ply slick
Rear – Hoosier H43307 R60A 22.5 x 7.2-13 bias ply slick
Wets:
Radial wets listed above
or
Front - Hoosier 44165 135/545-13 VFF
Rear - Hoosier 44170 165/580-13 VFF
Front tires may not be used as rears, and tires may not be mixed, i.e., radial tires may not be mixed with bias ply slick tires, bias
ply slick tires may not be mixed with VFF tires, and radial tires may not be mixed with VFF tires."

FA Update Formula Renault 2.0 spec line notes

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

neutralFA Formula Renault 2.0 (10-17) spec notes clarified: engine sealed, manual compliance required, tire choice unrestricted, no alterations except repairs.

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."

STU Increase Minimum Weight

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

slowerSTU GT3U minimum weight increases 150 to 250 pounds.

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

T1 Cadillac CT4-V Blackwing

#38003 from Touring Committee · Rule change · TB 25-04 (2025-04 Fastrack)

neutralCadillac CT4-V Blackwing added to T1 Spec Line 1115, 3564cc, 3750 lbs minimum weight.

In T1 Spec Lines, classify Cadillac CT4-V Blackwing as follows:

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

T1 Acceptance of Porsche 981 GT4 Clubsport into T1

#36664 from John Brown · Rule change · TB 25-05 (2025-05 Fastrack)

neutralPorsche 981 GT4 Clubsport added to T1 as spec line 4085, minimum weight 3100 lbs with driver.

In T1-GT4 Spec Lines, classify Porsche 981 GT4 Clubsport as follows:

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

T1 Request to Restore T1 Honda S2000 to Proper Weights

#37644 from David Mead · Rule change · TB 25-05 (2025-05 Fastrack)

fasterT1 Honda S2000 minimum weight reduced from 2950 lbs to 2900 lbs.

In T1 Spec Lines, Honda S2000, Spec Line 1530, change as follows:
Minimum Weight: "2950 2900"
Chassis Notes: "This spec line is set to expire as of 12/31/2025 if not represented in Majors competition in 2025."

T1 DCT Transmission in E46

#37964 from Matt Spicuzzi · Rule change · TB 25-05 (2025-05 Fastrack)

neutralT1 BMW E46 M3 permits BMW #GS7D36SG aftermarket sequential transmission in SL# 1060 and 1070.

In T1 Spec Lines, BMW E46 M3, add to Chassis Notes the following:
SL# 1060: "BMW #GS7D36SG transmission permitted as an aftermarket sequential option."
SL# 1070: "BMW #GS7D36SG transmission permitted as an aftermarket sequential option."

Applies to BMW M3 on this page: Ian Barberi

STU Wheel Size Inconsistency

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

neutralSTU wheel width rules clarified: cars ≤2,850 lbs max 8 inches, cars >2,850 lbs max 9 inches.

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."

T1 Reduce E92 M3 Minimum Weight to 3050

#38092 from Shane Brown · Rule change · TB 25-05 (2025-05 Fastrack)

fasterT1 BMW M3 E92 minimum weight reduced to 3300 lbs.

In T1 Spec Lines, BMW M3 E92 (08-13), Spec Line 1100, change Min. Weight as follows:
"3350 3300"

T1 Finalize Spec Line for T1 Darkhorse

#38106 from Touring Committee · Rule change · TB 25-05 (2025-05 Fastrack)

fasterT1 Mustang Darkhorse R gets 315 front and rear tyres, loses 500 lbs minimum weight to 3600.

In T1 Spec Lines, Mustang Darkhorse R (Mustang Challenge) Spec Line- 4119, change as follows:
Tire size: "305 315 (f) 315(r)"
Performance Control: "TBD"
Min. Weight with driver (LBS): "10.5 (f) 11 (r) 3600"
Chassis Notes: "Must conform to Mustang Challenge Rules. Tires conforming to Mustang Challenge rules are permitted. **This
car is not eligible for the Runoffs until it has competed in 3 Super Tour events.**"

FF Page 228, FF tire rule 9.1.1.10.e

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

neutralFF adds rocker arm and outboard suspension cars optional bias ply and VFF tires; removes front-as-rear rule, adds mixing restrictions.

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

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Alternatively, Formula F cars with rocker arm suspension (e.g., Swift DB1, 1987-90 Reynard) and/or outboard suspension on at
least one chassis end may use the following tires:
Dries:
Front - Hoosier H43130 R60A 20.0 x 6.0-13 or H43164 R60A 20.5 x 7.0-13 bias ply slick
or
Hoosier 44165 135/545-13 VFF
Rear – Hoosier H43307 R60A 22.5 x 7.2-13 bias ply slick
or
Hoosier 44170 165/580-13 VFF
Wets:
Radial wets or VFF tires listed above
or
Front - Hoosier 44165 135/545-13 VFF
Rear - Hoosier 44170 165/580-13 VFF
Front tires may not be used as rears, and tires may not be mixed, i.e., radial tires may not be mixed with bias ply slick tires, bias
ply slick tires may not be mixed with VFF tires, and radial tires may not be mixed with VFF tires."

STU Table C: STU-GT3U Clarification

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

fasterSTU Spec Line GT3U minimum weight reduced from plus 250 to plus 225 pounds; wheel and tire options clarified with weight adjustments.

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

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including the 225 lbs."

STU 2.8-3.2L N/A Engine Allowances

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

unclearSTU 2.8-3.2L N/A engines now allow 245 max tire width; over 3150 lbs may run 275 with 2% weight penalty.

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."

STU 2006-2015 Mazda Miata Intake Manifold

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

neutralSTU Mazda MZR may use Goodwin 61-2510 or Gato Performance 31972 intake manifold.

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 . "

FA Ligier JS F3 Tire Choice

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

neutralFA Ligier JS F3 front tires may be Hoosier 43363 240/580R13 MS, rear 43368 300/590R13 MS.

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."

STU Requesting Approval of the JDM Honda h23a

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

neutralSTU Honda JDM H23a added, 2259cc displacement, minimum weight per Chart, must meet ST engine regulations.

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.

STU STU-TCR Adjustments

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

slowerSTU-TCR tire width increases to 275 with weight adder raised from 100 to 150 pounds.

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."

STU Lotus Weight Reduction

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

fasterSTL/STU Lotus weight reduced: Evora GT4 to 2700 lbs, Elise Cup R to 2250 lbs, Elise/Exige SC to 2450-2550 lbs.

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"

STU Lotus Weight Reduction E&O

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

fasterSTU Lotus Elise SC and Exige SC weight reduced from 2450 to 2250 lbs.

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

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

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

slowerSTU Honda K24 engine swap weight increases by 2% effective November 1, 2025.

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

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

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

neutralFA class adds USF Pro 2000 car eligibility for Formula Atlantic racing.

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

STU Turbo Inlet Restrictor Table

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

slowerSTU 36mm restrictor allows 2830 lbs (up 10 lbs from 2820); 37mm allows 2980 lbs (down 5 lbs from 2985).

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

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

STU 275 Tire Rule

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

slowerSTU cars over 3150 lbs lose 275-tire option with 2% weight adder.

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."

T1 Keep S2000 Classification

#39344 from David Mead · Rule change · TB 25-12 (2025-12 Fastrack)

unclearUnable to summarize: letter states intent but provides no actual rule changes to S2000 specification.

In T1 Spec Lines, Honda S2000, change as follows:

STU STU Honda Engine weight penalty

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

fasterSTU Honda K20 and K24 engines lose 2% minimum weight penalty.

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

T1 Correcting and updating T1 GT4 spec lines

#39394 from Touring Committee · Rule change · TB 25-12 (2025-12 Fastrack)

In T1-GT4 Spec Lines, change as follows:

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

T1 BOP adjustments to non GT4 T1 cars

#39406 from Touring Committee · Rule change · TB 25-12 (2025-12 Fastrack)

fasterT1 non-GT4 cars: multiple restrictors enlarged (70mm to 73mm, 75mm to 78mm, 55mm to 60mm, 61mm to 70mm); one weight increased to 3600.

In T1 Spec Lines, change as follows:
Spec Line # 1134
Required Restrictor: "61mm 70mm - Flat Plate"
Spec Line # 1140
Required Restrictor: "72mm - Flat Plate"
Spec Line # "1175"
Maximum Displ.: "L76 5967cc OEM"
Minimum Weight: "3250"

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Required Restrictor: "80mm"
Engine Notes: "An L76 is an LS2 block with LS3 intake manifold and heads. All parts must be OEM. May resleeve to stock
parameters for engine repair."
Spec Line # 1180
Required Restrictor: "75mm 78mm - Flat Plate"
Spec Line # 1190
Required Restrictor: "70mm 73mm - Flat Plate"
Spec Line # 1200
Required Restrictor: "72mm 78mm - Flat Plate"
Spec Line # 1201
Required Restrictor: "70mm 73mm - Flat Plate"
Spec Line # 1210
Required Restrictor: "72mm - Flat Plate"
Spec Line # 1350
Required Restrictor: "(2) 55mm 60mm flat plate"
Spec Line # 1370
Required Restrictor: "(2) 55mm 60mm flat plate"
Spec Line # 1390
Required Restrictor: "(2) 55mm 60mm flat plate"
Spec Line # 1420 "*Spec line Expires 12/23"
Required Restrictor: "52mm FPR"
Spec Line # 1429
Required Restrictor: "75mm - FPR"
Spec Line # 1460
Weight: "3500 3600"
Required Restrictor: "70mm - FPR"
Spec Line # 1480
Required Restrictor: "80mm FPR"
Spec Line # 1490
Required Restrictor: "75mm - FPR"
Spec Line # 1590
Engine Notes: "90mm Throttle Body Permitted"
Spec Line # 1595
Required Restrictor: "72mm – FPR"
Spec Line # 1596
Required Restrictor: "61mm 70mm – FPR"
Spec Line # 4120
Required Restrictor: "75mm flat plate"

T1 Remove T1 Spec Line

#39407 from Touring Committee · Rule change · TB 25-12 (2025-12 Fastrack)

neutralT1 BMW M3 E92 (08-13) Spec Line 1090 removed entirely.

In T1 Spec Lines, BMW M3 E92 (08-13) Spec Line number 1090, delete Spec Line in its entirety.

FA Alternate Intake Manifold for MZR

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

unclearFA MZR gains alternate Noor P/N 0088-8-00 intake manifold with AT Power runners as option to Elan or Mazda Speed Elite.

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”."

FF Formula F Alternative Tire Rule Proposed Clarifications

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

neutralFF clarifies alternative tire eligibility for cars homologated 1989 or earlier with rocker arm or outboard suspension on all four corners.

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."

FA Engine Compression Rule Change Request

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

fasterFA Formula 1000 motorcycle-based engine loses maximum compression ratio 14.5:1 limit.

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."

T1 additional T1 adjustment

#39520 from Touring Committee · Rule change · TB 26-01 (2026-01 Fastrack)

unclearT1 Spec Line restrictor changes from 70mm flat plate to unspecified new specification.

In T1 Spec Line, Spec line # 1132, change Restrictor as follows:
"70mm - Flat Plate"

STU Request for Permission on Aftermarket Turbo Kit and Intake

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

fasterSTU Mazda MZR (LF, L3, L5) Turbo classified; Jack Spania Racing 70 mm intake manifold and Fab9 Tuning bottom-mount turbo kit approved.

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

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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.

FA Change Formula 1000 allowances

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

fasterFA Formula 1000 allows carbon fiber external panels, forward-facing gaps, raises floor to 125mm, adds eight 75×125mm rub blocks, expands diffuser to 110cm with 75mm radius transitions.

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

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licked by the air stream) shall be more than 125mm above the plane determined by the reference area designated by the entrant
and on a line perpendicular to that reference plane." Part 3.D of the December 2019 GCR F1000 (FB) Preparation Rules is also
modified as follows: "A maximum of eight (8) rub blocks of maximum dimension 75mm by 125mm are allowed anywhere on the
lower surface of the chassis and may extend below the reference plane." Part 3.E of the December 2019 GCR F1000 (FB)
Preparation Rules is modified as follows: "The radius of transitions between the diffuser sides and adjacent horizontal structures
may be up to 75mm. The width of the diffuser, as measured between its sides and above any radiused transitions, may not
exceed 110cm in any lateral section." The CRB may require the use of Flat Plate Intake Restrictors at any time."

FA Pro Mazda Classification and Performance Enhancement Proposal

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

fasterFA Pro Mazda: lower intake manifold now unrestricted, throttle body raised to 80mm, wing height must not exceed 99cm, bodywork width must not exceed 132cm.

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)."

T1 LS1 into Corvette C6 Spec Line Request

#39716 from Danny Kellermeyerhttps://crbscca.com/secu · Rule change · TB 26-02 (2026-02 Fastrack)

neutralT1 Corvette C6 LS1/LS6 Spec Line reinstated: 3200 lbs minimum weight, 70mm restrictor required.

In T1 Spec Lines, reinstate Spec Line # 1139, Chevrolet Corvette C6 (05-13) Includes Z51, GrandSport, Z06, Z06 Carbon, as
follows:
Max Displ: "LS1, LS6 OEM"
Min Weight: "3200"
Required Restrictor: "70mm"

What the rules allowed changed as listed; this does not say what any particular car ran.