BoP Labbeta

BoP Lab / Buttonwillow Raceway Park

T1 + SMX + EP 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; 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.

PosCarDriverClass#LapTheoreticalQualRace5-lap stintConsistencyTrapS1S2S3
1BMW 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
2BMW 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
3Mazda MiataJoe CarrEP121:52.034 B-P1:52.0341:59.603 A-Q11:59.157 A-R11:59.373 A-R1+0.724 A-R1131.6 A-R131.719 B-P32.405 B-P49.966 B-P
4Mazda MX-5Glen McCreadyEP41:53.088 B-Q21:52.9841:53.088 B-Q21:53.487 B-R21:54.617 B-R2+2.232 B-R2125.6 B-P30.761 B-R232.765 B-Q149.458 B-Q2
5Mazda MX-5 (2006)Ethan LampeSMX951:56.431 B-Q21:56.3711:56.431 B-Q21:57.417 B-R21:57.634 B-R2+0.462 B-R2109.8 B-R231.777 B-Q133.620 B-Q250.974 B-Q2
6Mazda RX-7Kurt FrietzscheEP401:56.468 B-Q11:55.5991:56.468 B-Q11:56.573 B-R11:57.721 B-R1+1.914 B-R1120.7 A-R231.324 B-Q134.071 B-R150.204 B-R1
7Mazda MX-5 (2013)Lincoln LarsonSMX121:56.503 A-Q21:56.5031:56.503 A-Q21:59.141 A-R12:00.335 A-R1+1.234 A-R1132.0 A-Q131.834 A-P33.724 A-P51.178 A-Q2
8Mazda MX-5 (2006)Jared KorthSMX271:56.725 A-Q11:56.6871:56.725 A-Q11:58.159 B-R21:58.422 B-R2+0.652 B-R2136.3 A-Q131.924 B-P33.696 A-Q151.067 A-Q1
9Mazda RX-7Brandon DroeseEP021:56.943 B-Q11:56.6571:56.943 B-Q11:58.611 B-R11:58.767 B-R1+0.718 B-R194.1 B-Q1, B-R131.953 B-R133.891 B-Q150.813 B-Q1
10Mazda MX-5 (2006)William WallisSMX521:56.947 A-Q11:56.8911:56.947 A-Q11:57.973 A-R11:58.799 A-R1+0.935 A-R1130.3 A-Q131.888 A-Q133.647 A-Q151.356 A-Q1
11Mazda MX-5 (2012)Emy Kissick 2+ carsSMX131:57.010 A-Q21:57.0101:57.010 A-Q21:58.594 A-R21:59.304 A-R2+1.778 A-R2133.6 A-R232.035 A-Q133.967 A-Q151.449 A-Q2
12Mazda MX-5Cooper HicksSMX861:57.154 B-Q21:57.0151:57.154 B-Q21:58.319 B-R11:58.608 B-R2+0.507 B-R2109.2 B-Q231.969 B-Q233.832 B-P51.214 B-P
13Mazda MX-5 (2008)Christian Hoagland 2+ carsSMX011:57.195 A-Q21:56.9211:57.195 A-Q21:58.021 A-R21:58.465 A-R2+1.234 A-R2136.1 A-Q131.987 A-Q133.897 A-P51.037 A-Q2
14Mazda MiataChristian Hoagland 2+ carsSMX011:57.211 B-P1:57.0771:57.885 B-Q21:58.294 B-R11:58.923 B-R1+0.703 B-R1108.8 B-P31.959 B-P33.927 B-P51.191 B-P
15Mazda MX-5 (2006)Joey AndrewsSMX1111:57.436 A-Q11:57.4011:57.436 A-Q11:58.757 A-R11:59.377 A-R1+1.179 A-R1141.6 A-Q232.124 A-Q133.813 A-Q151.464 A-Q1
16Mazda MX-5 (2006)Ryan GutileSMX1161:57.463 A-Q11:57.3391:57.463 A-Q11:58.772 A-R21:59.460 A-R2+1.350 A-R2133.6 A-R231.905 A-Q133.939 A-Q151.495 A-Q2
17Mazda MX-5 (2012)Gavin WardleSMX1691:57.612 A-Q21:57.4841:57.612 A-Q21:59.220 A-R21:59.535 A-R2+1.183 A-R2133.4 A-Q232.082 A-Q233.863 A-Q251.539 A-Q2
18Mazda Miata (2006)Wesley Mollno 2+ carsSMX1111:57.853 B-Q21:57.7451:57.853 B-Q21:59.001 B-R21:59.340 B-R2+0.516 B-R2112.1 B-R232.080 B-Q234.047 B-Q251.618 B-Q2
19Mazda MX-5 (2008)Aidan ShimbashiSMX721:57.891 A-Q21:57.7041:57.891 A-Q21:58.739 A-R21:59.436 A-R2+1.672 A-R2132.3 A-R232.361 A-P33.812 A-Q251.531 A-Q2
20Mazda MX-5 (2010)Bryce JohnsonSMX151:58.391 A-Q11:58.0891:58.391 A-Q11:59.447 A-R21:59.635 A-R2+0.805 A-R2134.6 A-Q132.180 A-Q134.098 A-Q151.811 A-Q1
21Mazda MX-5 (2006)Wesley Mollno 2+ carsSMX111:58.556 A-Q21:58.5561:58.556 A-Q21:59.393 A-R12:00.401 A-R1+1.119 A-R1132.7 A-R132.515 A-P34.154 A-Q152.048 A-Q2
22Mazda Miata (2007)Jon DaviesSMX671:58.557 B-Q11:57.9431:58.557 B-Q11:59.608 B-R12:00.014 B-R1+0.514 B-R1110.0 B-Q132.013 B-Q234.314 B-Q251.616 B-Q1
23Mazda MX-5 (2010)Thomas BelleminSMX251:58.671 B-P1:58.2451:59.087 B-Q21:59.878 B-R22:00.063 B-R2+0.552 B-R2109.8 B-Q232.172 B-P34.074 B-P51.999 B-Q2
24Mazda Miata (2007)Patrick DrinkwineSMX1511:58.954 B-Q21:58.5861:58.954 B-Q21:59.848 B-R22:00.219 B-R2+1.257 B-R2112.1 B-R132.431 B-Q234.268 B-Q251.887 B-Q2
25Mazda Miata (2012)Emy Kissick 2+ carsSMX131:59.056 B-Q21:58.9091:59.056 B-Q22:00.430 B-R12:00.784 B-R1+1.110 B-R1106.6 B-Q132.502 B-Q234.381 B-Q252.026 B-Q2
26Pontiac 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
27Ford 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
28Mazda MX-5 (2007)Andy ChittumSMX991:59.575 A-Q21:59.3401:59.575 A-Q22:00.160 A-R22:00.656 A-R2+0.703 A-R2132.0 A-R232.538 A-R234.495 A-P52.307 A-Q2
29Mazda MX-5 (2008)Ricardo ArrudaSMX161:59.640 B-Q11:59.3901:59.640 B-Q12:01.351 B-R12:01.755 B-R1+1.041 B-R1103.3 B-Q132.407 B-Q134.430 B-Q152.553 B-Q1
30Mazda MX5 (2010)Michael TraversSMX1322:00.055 B-R11:59.8842:00.568 B-Q12:00.055 B-R12:00.511 B-R1+0.738 B-R1115.3 B-P32.815 B-R234.508 B-R152.561 B-R1
31Mazda MX-5 (2015)Adrian ComstockSMX252:00.330 A-Q22:00.1822:00.330 A-Q22:00.678 A-R22:01.159 A-R2+0.837 A-R2132.0 A-R232.913 A-R234.721 A-R252.548 A-Q2
32BMW E30Sean LovettEP372:00.712 A-Q22:00.6252:00.712 A-Q22:01.864 A-R22:02.200 A-R1+0.528 A-R1127.6 A-Q232.761 A-Q134.806 A-Q153.058 A-Q2
33Mazda MX-5 (2006)Richard James 2+ carsSMX912:01.402 A-Q12:01.3532:01.402 A-Q12:02.469 A-R22:02.925 A-R2+1.646 A-R2126.2 A-R232.979 A-Q134.982 A-Q153.392 A-Q1
34Mazda MX-5 (2006)Amy MillsSMX22:01.543 A-Q22:01.5432:01.543 A-Q22:02.512 A-R22:03.543 A-R2+1.667 A-R2122.0 A-R233.434 A-Q134.905 A-Q153.264 A-Q2
35Mazda Miata (2006)Richard James 2+ carsSMX912:01.677 B-Q22:01.4502:01.677 B-Q22:01.929 B-R22:03.109 B-R2+1.515 B-R2106.1 B-Q232.922 B-R235.072 B-Q253.456 B-R2
36Porsche BoxsterWilliam RobinsonEP1982:01.940 A-Q12:01.6342:01.940 A-Q12:02.887 A-R12:03.347 A-R1+1.312 A-R1130.6 A-Q232.969 A-Q135.257 A-Q153.408 A-Q1
37Mazda MX-5Whitfield GreggEP172:03.660 B-Q22:03.3142:03.660 B-Q22:04.085 B-R12:05.470 B-R2+2.529 B-R297.7 B-R233.862 B-R235.422 B-R154.030 B-Q2

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
BMW M3T111:46.465Ian 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
Mazda MiataEP/SMX71:52.034Joe Carr1:57.853Wesley Mollno1:58.294Christian Hoagland131.6Joe Carr31.719Joe Carr32.405Joe Carr49.966Joe Carr
Mazda MX-5EP/SMX221:53.088Glen McCready1:53.088Glen McCready1:53.487Glen McCready141.6Joey Andrews30.761Glen McCready32.765Glen McCready49.458Glen McCready
Mazda RX-7EP21:56.468Kurt Frietzsche1:56.468Kurt Frietzsche1:56.573Kurt Frietzsche120.7Kurt Frietzsche31.324Kurt Frietzsche33.891Brandon Droese50.204Kurt Frietzsche
Pontiac GTOT111:59.123Ed Gless1:59.760Ed Gless1:59.123Ed Gless120.7Ed Gless32.383Ed Gless34.587Ed Gless51.370Ed Gless
Ford MustangT111:59.261Pratt Cole1:59.261Pratt Cole98.6Pratt Cole32.624Pratt Cole34.661Pratt Cole51.577Pratt Cole
BMW E30EP12:00.712Sean Lovett2:00.712Sean Lovett2:01.864Sean Lovett127.6Sean Lovett32.761Sean Lovett34.806Sean Lovett53.058Sean Lovett
Porsche BoxsterEP12:01.940William Robinson2:01.940William Robinson2:02.887William Robinson130.6William Robinson32.969William Robinson35.257William Robinson53.408William Robinson

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)

Summary

wordingT1 cars with aftermarket sequential transmissions get 10-inch max bellhousing; non-sequential cars gain 100 lbs weight break.

As printed in Fastrack

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."

T1 T1 GT4 adjustments

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

Summary

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

As printed in Fastrack

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"

Show 2 more lines

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)

Summary

wordingT1 removes GCR Section 9.1.9.1.A. and T1 Spec Lines entirely, sunsetting pre-2023 Touring 1 rules.

As printed in Fastrack

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

EP Investigate Parity of Z3

#33343 from Tim Schreyer · Rule change · TB 23-01 (2023-01 Fastrack)

Summary

slowerEP BMW Z3 2.5L intake restrictor reduced from 58mm to 56mm flat plate.

As printed in Fastrack

Effective 4/1/2023 In EP Spec Line BMW Z3 2.5L, change Notes as follows:
"58 56mm Flat Plate Intake Restrictor is required with both stock or alternate throttle body."

T1 Clarification for Camaro Gen5 2010-2015

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

Summary

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

As printed in Fastrack

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.

T1 T1 GT4 adjustments

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

Summary

wordingT1 GT4 weights clarified for nine cars, ranging from 3200 lbs Porsche 718 Cayman to 3575 lbs Aston Martin.

As printed in Fastrack

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

Show 3 more lines

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

T1 Touring 1 Tire Sizes

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

Summary

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

As printed in Fastrack

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)

Summary

cars addedT1 Ford Mustang S197 (05-14) reinstated with 3550 lbs minimum weight, 75mm restrictor, Voodoo engine permitted.

As printed in Fastrack

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

EP 914-6 Valve Size Correction

#34185 from Kip VanSteenburg · Rule change · TB 23-06 (2023-05 Fastrack)

Summary

fasterEP Porsche 914-6 2.0L intake valves increase to 2.0 mm, exhaust valves corrected to 38.0 mm.

As printed in Fastrack

In EP Spec Lines, Porsche 914 - 6 2.0L, change Valves IN & EX mm/(in.) as follows:
"(I) 41.9 2.0/(1.65)
(E) 38.1 0/(1.50)"

T1 Gen 5 Camaro Engine

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

Summary

cars addedT1 Chevrolet Camaro Gen 5 LS7 gets two spec lines: 1131 with 70mm restrictor, 1136 with 53mm restrictor, both 3450 lbs minimum.

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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."

Show 18 more lines

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)

Summary

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

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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"

EP Correct Intake Valve Size on 1500cc Midget/Spitfire

#34419 from Production Committee · Rule change · TB 23-06 (2023-05 Fastrack)

Summary

wordingFP and HP Sprite, Midget, and Spitfire 1500 intake valve size corrected to 36.6/(1.44).

As printed in Fastrack

In FP Spec Lines, Austin-Healey Sprite Mk. I, II,III, IV MG Midget Mk I,II, III, IV & 1500, change Intake Valve Size as follows:
"(I) 36.65.3/(1.44)"
In FP Spec Lines, Triumph Spitfire Mk. IV & 1500, change Intake Valve Size as follows:
"(I) 36.65.5/(1.440)"
In HP Spec Lines, Triumph Spitfire 1500, change Intake Valve Size as follows:
"(I) 36.65.5/(1.440)"
In HP Spec Lines, Triumph Spitfire Mk. III & IV 1500, change Intake Valve Size as follows:
"(I) 36.65.5/(1.440)"

T1 Ford Mustang S197 (05-14) Clarification

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

Summary

wordingT1 Ford Mustang S197 05-14 now requires OEM 8.8 differential housing.

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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)

Summary

wordingT1 Dodge Viper ACR / SRT RT-10 and ACR/ACR-X spec lines 1350 and 1370 remove 12/23 expiration.

As printed in Fastrack

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)

Summary

wordingT1 GT4 McLaren 570S, Mercedes AMG GT4, and Porsche 718 Cayman GT4 CS MR now eligible for Runoffs competition.

As printed in Fastrack

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)

Summary

wordingT1 GT4 BMW M4 Spec Line Number changed from 4050 to 4030.

As printed in Fastrack

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

EP Hub Note Clean Up In EP TR8 Spec Line

#34649 from Jeff young · Rule change · TB 23-09 (2023-09 Fastrack)

Summary

wordingEP Triumph TR8 78-81 removes alternate front hub allowance note; stock hubs now required.

As printed in Fastrack

In the EP Spec Lines, Triumph TR8 (78-81), remove the following wording from Notes:
"Alternate front hubs are allowed provided they are of the same external dimensions as stock and weigh no less than the stock
hubs."

EP Triumph GT6 Adjustments

#34662 from ANTHONY PARKER · Rule change · TB 23-09 (2023-09 Fastrack)

Summary

unclearEP Triumph GT6 carburetors change from SU or Stromberg to 1.5" Auto-type.

As printed in Fastrack

In EP Spec Lines, Triumph GT6, change Carburetor. No. & Type as follows:
"(2) 1.5” SU or Stromberg Auto-type carburetor(s)"

EP Triumph GT6 Adjustments: Brakes

#34663 from ANTHONY PARKER · Rule change · TB 23-09 (2023-09 Fastrack)

Summary

wordingEP Triumph GT6 brakes may now use TR-6 standard or alternate calipers and discs.

As printed in Fastrack

In EP Spec Lines, Triumph GT6, add the following to Brakes Alt.: mm/(in.):
"(F) Calipers & discs from TR-6 (std. or alt)"

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)

Summary

cars addedT1 Chevrolet Corvette C5 LS2 added with 6000cc displacement, 3300 lbs minimum weight, 72mm flat plate restrictor.

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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)

Summary

cars addedT1 Porsche 997-1 GT3 Cup added at spec line 4210, minimum weight 3050 lbs.

As printed in Fastrack

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)

Summary

cars addedT1 Chevrolet Corvette C7 (14-19) including Z51, Grandsport newly classified as homologated car.

As printed in Fastrack

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.

EP Porsche 944/924S Rule Change Request

#35002 from Adam Achepohl · Rule change · TB 23-12 (2023-12 Fastrack)

Summary

cars addedEP Porsche 944/924S combines 2.5L and 2.7L variants with new weights: 2250–2415 lbs depending on engine and year.

As printed in Fastrack

In EP Spec Lines, delete the Porsche 944/924S 2.5L (2V) (83-88) spec line entirely, and create a new spec line for Porsche
944/924S 2.5L(2V) 2.7L(2V) (83-89) as follows:

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

EP Triumph GT6 Adjustments

#35054 from ANTHONY PARKER · Rule change · TB 23-12 (2023-12 Fastrack)

Summary

fasterEP Triumph GT6 minimum weight reduced to 1800 lbs.

As printed in Fastrack

In EP Spec Lines, Triumph GT6, change weight as follows:
"1830 1800"

T1 Camaro Gen 5 Weight Reduction Due to Competitive Disadvantage

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

Summary

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

As printed in Fastrack

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)

Summary

wordingT1 Aston Martin Vantage permitted to use OEM Sportshift II transmission.

As printed in Fastrack

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

EP Request to Review Z3 2.5 Spec Line

#35073 from Tim Schreyer · Rule change · TB 24-01 (2024-01 Fastrack)

Summary

slowerEP BMW Z3 2.5L weight increases to 2500 lbs, 2563 lbs with turbo, 2625 lbs with supercharger.

As printed in Fastrack

In EP spec line, BMW Z3 2.5L, change weight as follows:
"2450 2500
*2511 2563
**2573 2625"

T1 GT4 batch adjustment in T1

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

Summary

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

As printed in Fastrack

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)

Summary

wordingT1 spec lines 1000, 1010, 1020, 1040, 1360, 1400–1410, 1520–1680, 1700–1720 deleted entirely.

As printed in Fastrack

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.

EP Miata Alternate Head

#35253 from Don Tucker · Rule change · TB 24-01 (2024-01 Fastrack)

Summary

fasterEP Mazda MX-5 1.8L 1990-97 minimum weight drops to 2150 lbs; 1994-97 variants to 2000, 2050, 2100 lbs respectively.

As printed in Fastrack

In EP Spec Lines, Mazda MX-5 /Miata 1.8L (90-97), change weight as follows:
"2200 2150"
Mazda MX-5 /Miata (94-97)
"2035 2000
*2086 2050
**2137 2100"

Applies to Mazda Miata on this page: Joe Carr

Applies to Mazda MX-5 on this page: Glen McCready, Whitfield Gregg

EP Triumph GT6 Adjustments

#35255 from Anthony Parker · Rule change · TB 24-01 (2024-01 Fastrack)

Summary

fasterEP Triumph GT6 dual 1.75" carbs weight drops to 1940 lbs; triple Weber 40 DCOE options consolidated.

As printed in Fastrack

In EP spec line, Triumph GT6, make the following change in the Notes section:
"Two (2) 1.75” auto-type carburetors @ 1970 40 lbs. Three (3) Weber 40 DCOE on IR manifold with 28mm chokes @ 1990
lbs. Laycock overdrive, May use 5 speed gearbox w/o overdrive. Three (3) Weber 40mm DCOE w/28mm venturi on individual
runner manifold @ 2020 lb."

EP Honda S2000 throttle body

#35272 from Aaron Johnson · Rule change · TB 24-01 (2024-01 Fastrack)

Summary

fasterEP Honda S2000 fuel injected throttle body inside diameter increases from 62mm to 64mm.

As printed in Fastrack

In EP spec line, Honda S2000, make the following changes to its spec line:
Fuel Injected Equipped Throttle Body Inside Diameter: "62 64"
Notes: "Comp. Ratio limited to 12.0:1. Valve lift limited to .500”. An adaptor plate can be used to mount the 62mm throttle body
from '00-05 to the '06-09 intake manifold. The adaptor plate can be no more than 1.25" thick, and its bore must not exceed the
"Fuel Injected Equipped Throttle Body Inside Diameter" maximum spec of 64mm."

EP Correction within Triumph TR8 Spec Line

#35315 from Production Committee · Rule change · TB 24-01 (2024-01 Fastrack)

Summary

wordingEP Triumph TR8 dry sump allowance moved from carburetor line to notes section.

As printed in Fastrack

In EP spec line, Triumph TR8 (78-81), move the "Dry sump allowed" wording to the appropriate location as follows:
Carburetor. No. & Type: “Zenith Stromberg carbs or fuel injection. Dry sump is allowed.”
Notes: “Comp. Ratio limited to 12.0:1, Valve lift limited to .500”. Dry sump is allowed.”

EP Correction to EP 924S/944 Spec Line

#35317 from Production Committee · Rule change · TB 24-01 (2024-01 Fastrack)

Summary

wordingEP Porsche 944/924S 2.5L and 2.7L weight minimums corrected: 2479cc to 2306/2363 lbs, 2681cc to 2358/2415 lbs.

As printed in Fastrack

In EP spec line, Porsche 944/924S 2.5L (2V) / 2.7L (2V) (83-89), change Weight as follows:

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

T1 C8 Corvette T1 Restrictor Plate Request

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

Summary

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

As printed in Fastrack

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)

Summary

removedT1 NEW class removes 23 spec lines including Acura NSX, Ferrari, Porsche 996, Nissan Z cars, and others; Porsche 997 spec line 1680 expiration removed.

As printed in Fastrack

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*"

EP Update 1988-1991 Civic to Match 1988-1991 CRX

#35399 from Enrik Benazic · Rule change · TB 24-02 (2024-01 Fastrack)

Summary

fasterHP Honda Civic 1.5 (88-91) weight reduced to 2175 lbs base, 2229 lbs with power adder, 2284 lbs with two.

As printed in Fastrack

In HP, make the following weight change:
Honda Civic 1.5 (88-91)
“2245 2175
*2301 2229
**2357 2284”

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)

Summary

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

As printed in Fastrack

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.

EP GCR Correction - Redundant HP Spec Lines

#35623 from Production Committee · Rule change · TB 24-03 (2024-03 Fastrack)

Summary

wordingHP removes four redundant VW spec lines: Rabbit Cabriolet 1780, Scirocco 1588, Scirocco 1780 8-valve, Scirocco 1588.

As printed in Fastrack

In HP Spec Lines, delete the following redundant spec lines in their entirety:
Spec line #10 - VW Rabbit Cabriolet 1780
Spec line #3 - VW Scirocco 1588
Spec line #4 - VW Scirocco 1780 (8-valve) (83-88)
Spec line #5 - VW Scirocco 1588

T1 Honda S2000

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

Summary

cars addedT1 Honda S2000 classified with 2400 lb minimum weight, 2950 cc displacement, 4.75" supercharger pulley.

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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

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

EP NIssan 300ZX Z31 to EP

#35830 from Murphy Nichols · Rule change · TB 24-06 (2024-06 Fastrack)

Summary

cars addedNissan 300ZX 84-89 classified to EP at 2550 lbs minimum, 2960cc 6-cyl SOHC, fuel injection, 12.0:1 compression limit, 0.500" valve lift limit.

As printed in Fastrack

In EP Spec Lines, classify Nissan 300ZX (84-89), as follows:

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

EP RX7 1993 and Up Request In EP Spec Lines, classify

#36031 from Edward Zabinski · Rule change · TB 24-06 (2024-06 Fastrack)

Summary

cars addedMazda RX-7 92-97 newly classified EP Prep Level 2 at 2200–2310 lbs with 13B 6-port rotary engine.

As printed in Fastrack

Mazda RX-7 (92-97) as follows:

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

EP Clean-up Multiple EP RX-8 Spec Lines In EP

#36156 from Production Committee · Rule change · TB 24-06 (2024-06 Fastrack)

Summary

wordingEP Mazda RX-8 (04-11) alternate spec line removed; one primary line remains.

As printed in Fastrack

Spec Lines, make the following changes to the two Mazda RX-8 spec lines.
Remove spec line entirely:
Mazda RX-8 (04-11)
Remove the wording "alternate":
Mazda RX-8 (04-11)(alternate)
Spec Mazda (SM/SMX) None.

EP Errant entry in HP production line item

#36231 from Angus Crome · Rule change · TB 24-08 (2024-08 Fastrack)

Summary

wordingHP Volkswagen Golf and Jetta 85-92 track correction: front 1537mm (60.5in), rear 1529mm (60.2in).

As printed in Fastrack

In HP Spec Lines, change Track (F/R)mm/(in.) as follows:
Volkswagen Golf (GTI, GT, GL) (85-92): "2 1537/1529 (60.5/60.2)"
Volkswagen Jetta (GLI, GL) (85-92): "2 1537/1529 (60.5/60.2)"

SMX SMX Camera Rule Correction

#36496 from Paul Gauzens · Rule change · TB 24-09 (2024-09 Fastrack)

Summary

wordingSMX Spec MX-5 camera requirement wording changed; non-functioning recorder now grounds for penalty or disqualification.

As printed in Fastrack

In GCR, Section 9.1.7.1.D.21., change as follows:
"Cars running in Spec MX-5 must have a functioning video recorder/camera during all qualifying and race sessions as described
in 9.3.11. Upon request by an SCCA official, competitors must provide their video recording/data, which may be used by the
SCCA for any purpose including but not limited to rule enforcement and marketing. Failure to comply with a video request from
an official, or having a non-functioning video recorder/camera may will be grounds for penalty or disqualification."

SMX Committee) AIM ECU Protocol

#36556 from Spec Mazda (SM/SMX · Rule change · TB 24-09 (2024-09 Fastrack)

Summary

wordingSMX Spec MX-5 must run latest AIM Data Logger Spec MX-5 ECU Protocol; wording clarification for technical compliance.

As printed in Fastrack

In GCR, Section 9.1.7.1.D.20., add the following:
“e. All cars must run the latest AIM Data Logger Spec MX-5 ECU Protocol.”
These specifications are part of the SCCA GCR and all automobiles shall conform to GCR Section 9.
A. PURPOSE AND
INTENT
Spec MX-5 (SMX) is based on four pillars: affordability, reliability, tech-ability, and fun to drive, the (SMX) Spec MX-5 car
provides the membership with the opportunity to compete in similarly prepared, low cost, 2006-2015 production-based MX-
5 car with limited modifications, intended to help deliver the most fair and competitive racing competition in SCCA Road

Show 660 more lines

Racing
B. CLASSIFIED CARS
AND WEIGHTS
2006-2015 production-based MX-5
Cars are to be weighed with the driver and required ballast.
C. AUTHORIZED
MODIFICATIONS
Only the left-hand drive, North American-version of the 2006-2015 Mazda MX-5 convertible & power retractable hardtop
(PRHT) are eligible. The original OE vehicle identification number (VIN) stamped on the firewall must correspond with the
model year automobile as classified. VIN plates or stampings must remain in place, with the firewall VIN taking precedence.
A Mazda Factory Shop Manual for the specific make, model, and year of automobile is required to be in the possession
of each entrant. The manual may be in the form of printed material, microfiche, CDs, DVDs, and/ or Internet access to
manufacturer sponsored web-based databases that is readily accessible at time of inspection. The manual is intended to
aid scrutineers in identifying parts and the configuration of the automobile.
The items outlined in this VTS document represent the only modifications and safety items permitted and/or required on
Spec MX-5 vehicles other than safety items as required in SCCA’s current GCR Section
9. Parts and components may not perform an unauthorized function (i.e. Modifications must be stated as authorized or
cannot be done).
If the Mazda Factory Manual or these rules provide only a partial specification or no specification at all, the Mazda parts may
not be modified beyond what is permitted in these rules. Compliance will be determined by comparison to new or like parts
and/or the parts compliance measurement listing delivered by Mazda. Other approved parts with only a partial specification
or no specification available in these rules may not be modified.
Assembly, rebuild, and refurbishment procedures, and all associated dimensions must adhere to the published factory
service procedures, except as otherwise stated in these rules. No components may be added or omitted from those
specified by the published factory service procedures. All components must be comply with stated standard dimensions.
It is permitted to use industry standard procedures to repair damaged components.
The use of any painting, coating, plating, metal treatment process or impregnating substance (e.g., anti- friction, thermal
barrier, oil shedding coatings, chrome, anodizing, REM, isotropic finishing, etc.) to any internal engine surface, internal
axle components, internal transmission or differential surface, internal or external surfaces of the intake manifold, exhaust
manifold or down tube, is prohibited.
D. VEHICLE
TECHNICAL
SPECIFICATIONS
(VTS)
1. Vehicle Weight
a. The minimum vehicle weight with driver is 2,525.0 lb.
2. Ballast
If ballast is required to meet the required minimum weight, it must be added as follows:
a. A ballast base plate must be securely mounted using the factory OE passenger seat mounting bolt holes and bolts. Any number
of additional segments of ballast may be attached to the base plate.
b. Each segment of ballast must be fastened to the base plate with a minimum of two (2) one-half (1/2) inch bolts/studs and
positive lock nuts of SAE Grade 5/ Metric 8.8 or better and must utilize large diameter, load distributing washers. In lieu of
positive lock nuts it is permitted to positively thread the additional segments of weight into the base plate.
c. Holes are not permitted to be drilled in the floor pan to mount ballast.
3. Chassis
a. Towing eyes per SCCA’s current GCR Section 9.3 are required. There must be an arrow that strongly contrasts with the vehicle
paint scheme pointing to each tow eyestrap.
9.1.7.1 SPEC MX-5 (SMX)
b. All cars must use the front subframe PT# - NE51-34-800C
c. All cars must use the rear subframe PT# - NE51-28-800B.
d. OE strut tower brace is required; it is comprised of three (3) components; see Table 1 for part numbers.
e. An engine to fender brace located on the passenger side of the engine bay may be used if mounted in such a way that it does not foul brake
lines, fuel lines, or other systems that would interfere with the safe operation of the vehicle under race conditions – see Table 1 for allowed
modifications. (Mazda Motorsports PT# 0000-07-5600)
f. Disabling or removing of the door locking mechanism must be performed.
g. To facilitate frequent lifting of the vehicle, a 3/4” boxed tube not to exceed 12” long may be added under the rocker panel inboard of
the factory pinch weld flange on each side of the vehicle.
h. Convertible tops/power retractable hard tops (PRHT) and attaching hardware must be completely removed.
i. All chassis, structural, and electrical repairs, if performed, must be in conformity with factory procedures, specifications, and dimensions.
Unless specifically authorized by the manufacturer for repair or permitted by these rules, no reinforcement (e.g., seam welding, material
addition, etc.) is permitted.
j. Removal of excess wiring is permitted provided it serves no other purpose and does not splice or interrupt the OE harnesses. Removal of the
following systems is permitted: audio equip- ment; power seats; airbag/supplemental restraint systems components; heated seats; interior
lighting; power windows; and power door locks. (No additional wiring may be added except as permitted in other sections - e.g., Section 16:
Electrical Equipment.)
Table 1: Strut Tower Brace Parts
Description Mazda Part #
Right Side of Strut Tower
Brace
NE57-56-48X
Left Side of Strut Tower
Brace
NE57-56-49X
Center Section of Strut
Tower Brace
NE57-56-48ZA
k. A hole is permitted to be drilled in part #’s NE57-56-48X and NE57-56-49X to allow for access to the shock adjuster screw is permitted (it is
recommended that the hole not be larger than 15mm); NE57-56-48X may be modified in order to allow room for the engine passenger side
engine brace; no other modifications or other braces are permitted.
l. MX-5 donor chassis with originally equipped with 16” OE wheels require installation of
OE strut tower brace (part # NE57-56-35XA).
m. To facilitate engine bay air flow for cooling purposes it is permitted to remove the section outlined below in red from OE PT# NE57-56-
35XA. Block-off plates must be installed at the fresh air vent for the HVAC module at the firewall under the cowl to isolate driver
compart- ment from engine compartment.
(FIREWALL BLOCKOFF PLATE 0000-07-5832) No additional modifications are permitted.
4. Body
a. Interior and exterior door handles are required to remain operable. Alternate interior door handles or cord/strap are permitted.
b. The driver’s and passenger’s side inner door structural panel may be removed to fit the cage.
c. The stock side impact/anti-intrusion beam must not be modified or removed.
d. Door locking mechanisms must be disabled or removed.
e. A minimum of two (2) of the brake lights must be in working order per the current GCR Section 9.1.
f. The two (2) OE unmodified, external mirrors for the correct the Mazda MX-5 (left and right) are required; they must be
mounted in stock location and may not be modified.
g. OE interior rearview mirror or an aftermarket rearview mirror must be used.
h. 2006-2015 MX-5 bodywork may be updated or backdated, OE body parts only. (This includes Mazda OE accessory body
parts such as trunk lid spoiler, side skirts, front air dam.)
i. Mazda Motorsports’ fiberglass headlamp replacements may be used; (See table 2)
no modifications or substitutions are permitted; exceptions: painting, covering, and wrapping.
Table 2: Headlamp Replacement Covers
Model Year Mazda Part # Description
2006-2008 0000-07-5818-LT Left Side
2006-2008 0000-07-5818-RT Right Side
2009-2015 0000-07-5819-LT Left Side
2009-2015 0000-07-5819-RT Right Side
j. Lexan windshield may be used in place of the stock windshield. (Mazda Motorsports PT# -
0000-07-5101-5S)
k. Windshield clips per current GCR Section 9.3 windshield clips are recommended.
l. Hood and trunk pins or clips are permitted. Factory hood and trunk latches must remain intact and operational and may not be
removed, disabled or altered.
m. Front under hood weather strip must remain intact PT#- NE51-56-750
n. Rear under hood weather strip must remain intact PT#- NE51-56-760
o. Modification of release cables is permitted to facilitate external pull/opening straps/pulls/cords.
p. A radiator screen of 0.125” minimum stainless-steel mesh may be added in front of the radiator.
1. The screen must be a single layer and must be installed to the bumper cover and or grill and be contained entirely within the
bodywork of the vehicle.
2. Tape may be applied to the mesh screen.
3. The OE grill must remain intact.
q. It is allowed to apply roll bar padding to the crash support bar (52-070) located behind the front bumper to prevent damage to the
bumper.
r. Front and rear fender lips may be rolled to prevent tire damage.
s. Front OE fender liners must be intact and unmodified, except for what is allowed in section 13. J regarding brake ducts.
Repairs due to on-track damage is allowed so long as it serves no other purpose.
t. OE fog lights lens/glass must be removed. This will allow for the installation of brake duct kit (Mazda Motorsports’ part # 0000-03-
5301-NC.) The remaining opening from the fog light lens must either be blocked, or a connection must be made from the fog lamp
opening/hole in the bumper fascia to a brake duct attached to the hub.
u. Side marker lenses may be removed, and holes may be covered.
v. OE hard top or the unmodified Mazda Motorsports hard top (part # 0000-07-5901-CC)
are permitted.
w. PRHT chassis cars must trim the finish panel with the 3rd brake light to fit one of the approved hard tops.
1. Hhardtops may be painted or wrapped.
2. OE hard top latches must be removed and replaced with positive fasteners.
3. The front of the hard top may attach to the upper windshield bar of the roll cage.
4. It is permitted to run one single piece of racer tape to cover the leading edge of the after- market hard top where it meets
the factory windshield frame.
5. Openings beneath the hard top seal to the body are not permitted. The hard top must be securely mounted to the body of the vehicle
and perform no other purpose.
6. Body repair must be performed to maintain stock body contours, lips, profiles, etc. body repair modification must not increase clearance.
x. To improve driver’s exit through the window area, the driver and passenger vent window and vent window supporting frame may be removed
as an assembly.
1. Vent windows may be modified to accept fresh air ducting.
y. OE radio antennas may be removed. Antennas for two-way radios may be added.
z. Insulation & undercoating may be removed.
aa. All cars must run with both the front door windows fully open (i.e. fully down).
5. Cockpit /
Trunk
a. All interior trim components such as carpets, seats, cargo bins, seat belts, floor mat, firewall insu- lation/blanket, sound deadener patches,
undercoating, radio systems, speakers, dome lights, grab handles, sun visors and their insulating and attaching materials, must be removed.
Other than to provide for the installation of required safety equipment or other authorized modifications, no other driver/passenger
compartment alterations or gutting are permitted.
b. It is permitted to install a radio replacement panel.
c. The outer edges of the dashboard may be cut the minimum amount required to install the roll cage.
d. Air bag systems must be disarmed and must be removed.
e. It is permitted to remove all components of the cruise control system.
f. The top portion of the door panels containing the door latch release handle must remain intact.
g. The lower portion of the door panels must be removed for installation of the roll cage. Gutting of the door may not go outside of the factory
seal.
h. The door window glass and window operating mechanisms must be removed.
i. The OE dashboard and its attaching hardware and brackets must be retained.
j. For installation of required safety equipment, however, it is permitted to modify the OE dash bar, so long as it is outboard of the first dash support
brackets (illustration below). Modification of the first dash support brackets, nor inboard from them, is not permitted. The OE dash bar must be
securely mounted.
k. The HVAC control module located under the dash may be removed together with the following: blower motor, evaporator core,
heater core and associated ducting. Once removed it is permitted to block the blower inlet passage on the firewall.
l. All openings between the driver/passenger compartment and the trunk / gas tank area that include the filler tube & fuel tank vent
must be filled completely with a metal bulkhead that is securely mounted (E.G. nuts/bolts, nut-serts, rivets). This shall close the
entire trunk from the driver/ passenger compartment and comply with current GCR Section 9.3.
m. Mazda Motorsports’ finish panel trim kit (part # 0000-07-5822) may be used to create the required bulkhead above
n. It is permitted to remove the driver’s side factory seat mounts, but not the floor pan.
o. It is permitted to remove the horn and all associated horn related components.
p. OE driver’s seat must be replaced with a one-piece bucket-type race seat per current GCR Section 9.3.
q. The passenger seat must be removed.
r. Any steering wheel except wood rimmed types may be used.
s. Any shift knob may be used.
t. The air conditioning equipment located in the engine compartment (AC compressor assembly, associated lines/dryer and the
condenser) must be removed.
u. Alternate gauges and instruments may be added. The original instrument cluster must remain connected and functional However,
it may be relocated to allow the mounting of an aftermarket dash such as an AiM. The wiring to relocate the dash may not be cut or
extended, it may only be re-routed. The remainder of the dashboard or panel must remain intact.
v. Modifications may be made to the foot pedals to improve the comfort and accessibility to the driver; relocation of mounting
points is not permitted.
1. Dead pedal/footrest and heel stop may be added.
w. Instrument clusters must be unmodified OE parts .
x. Two-way radios may be used.
y. Alternate means of windshield defrosting is permitted
6. Engine
Modifications
6.1. General
a. No modifications to the engine are permitted, except where specifically authorized within these rules. This includes but is not
limited to: all fuel injection and engine management components, as well as electrical, cooling, and lubrication systems.
b. All systems, unless otherwise stated, are subject to test procedures and must conform to OE
specifications as stated in the Mazda Factory Service Manual.
c. Permitted engine maintenance includes the replacement, but not modification, of external engine and engine systems parts.
1. No balancing, blue printing, lightening, polishing or other modification of moving parts of the engine is permitted.
2. All parts in the engine must be OE parts unless specified in this rule set.
3. For all Mazda part numbers in these specifications, superseding part numbers are consid- ered equivalent.
d. Compression ratio for 2.0L engines must be 11.00:1; calculated using the official Spec MX-5 calculator.
6.2. Engine Block
a. The engine block may be decked or milled to achieve the class specified compression ratio. Honing of cylinders is permitted to accommodate
piston clearance so long as a maximum standard diameter is not exceeded shown in Table 3.
b. The cylinders may be bored to accommodate piston clearance requirements so long as maximum permitted overbore diameter is not exceeded
shown in Table 3 below.
Table 3: Piston Sizes
Piston Part # Bore Diameter Max
Standard 0000-01-5310 87.6046mm (3.449”)
Allowed Overbore (.020) 0000-01-5310-OS 88.1126mm (3.469”)
c. It is not permitted to overbore a single cylinder; all cylinders must be bored equally.
d. Sleeving of cylinders is not permitted.
6.3. Crankshaft
a. OE Mazda MZR 2.0L (2009-2015) manual transmission crankshaft (part # LF9G-11-301) must be used with no modifications except for
machining or polishing polishing and/or machining of the bearing surfaces to allow the use of main and rod bearings as permitted
in Table 4 below.
Table 4: Crankshaft Measurements
easurement iameter Diameter
b. OE crankshaft (Mazda part # LF9G-11-301) must weigh a minimum of 31.75lb.
c. Maximum permitted stroke is as follows: 3.27” / 83.1mm
d. Shot peening is prohibited.
e. Bearings
1. Main and rod bearings must not be modified; coatings are not permitted.
2. OE bearings are permitted.
3. The only bearing sizes permitted other than OE are listed in see Table 5.
Sizes
Bearing Type Minimum Bearing
Width Minimum Bearing
Thickness Minimum Bearing
Weight Part #
Main Bearings
(Standard H) .630” 0.097” N/A 0000-01-5215-MB
Main Bearing
(Standard HX) .630” 0.097” N/A 0000-01-5216-MB
Rod Bearings
(Standard H) .630” 0.057” 28g 0000-01-5213-RB
Rod Bearing
(Standard HX) .630” 0.057” 28g 0000-01-5214-RB
f. The crank trigger must not be modified; it must be installed per the Mazda Factory Service Manual.
g. OE crank pulley/balancer (Mazda part # LF94-11-400) must not be modified and must be installed per the Mazda Factory Service Manual.
h. Knife edging of the crankshaft is not permitted.
i. Modifications to the crankshaft counterweights are not permitted.
j. Coatings, REM or metal treatments of any kind are not permitted.
k. Alternate shifter bushing located at the bottom of the shift lever is allowed.
6.4. Connecting Rods
a. OE Mazda MX-5 (2009-2015) manual transmission unmodified connecting rods (part # LF9G- 11-210) must be used. Connecting
rod weight with cap and bolts must not be less than 530 grams.
6.5. Pistons
a. Mazda Motorsports’ competition pistons (standard bore part # 0000-01-5310; oversized part # 0000-01-5310 OS) are required;
no modification is permitted.
b. The minimum weight of the piston, less wrist pin and hardware, must not be lighter than 290 grams.
c. Mazda Motorsports’ competition wrist pin (part # 0000-01-5310-PN) must be used.
d. The minimum weight of the wrist pin must not be lighter than 80 grams.
e. Modification of the piston ring end gap width is permitted.
6.6. Cylinder Head
a. Mazda Motorsports’ competition cylinder head (part # 0000-01-5300) must be used; no modi- fications to the cylinder head are
permitted outside of the gasket face surface outlined below in Table 6.
b. Intake runner CC volume is 182cc +/- 1cc.
c. Exhaust runner CC volume is 114cc +/- 1cc.
d. Combustion chamber volume may not be below 41cc.
e. The gasket face of the cylinder head may be resurfaced provided the maximum allowed compression ratio is not
exceeded.
I. Surfacing of the head gasket surfaced must be in a flat plane.
II. Cylinder head gasket surface distortion may not exceed .010mm or 0.004”.
f. The minimum height of the cylinder head as measured must be at least (TBA)
g. The following head gaskets in Table 6 below are permitted; no other gaskets may be used.
Table 6: Head Gasket Measurements
Description Thickness Mazda Part #
OE Gasket 0.017” approximate crush
depth L3G2-10-271A
Competition
Gasket 0.55mm (0.021”) 0000-01-5319-21
Competition
Gasket 0.75mm (0.030”) 0000-01-5319-30
Competition
Gasket 1.0mm (0.040”) 0000-01-5319-40
Competition
Gasket 1.3mm (0.051”) 0000-01-5319-51
6.7. Camshaft and Camshaft Timing
a. Camshafts must not be modified; see Table 7 for OE camshaft part numbers.
Table 7: Camshaft part numbers
Description Mazda Part #
Intake Cam L3E3-12-420
Exhaust Cam L309-12-441B
b. Camshaft and crankshaft sprockets must not be modified; see Table 8 for part numbers.
shaft Sprocket Part #s
t #
4X0C
425
c. Cam timing must not be altered; chain must be installed as stated in the Mazda Factory Service Manual.
d. OE timing chain (Mazda part # LF7A-12-201) is required; no modification is permitted.
e. OE timing chain components must be used; see Table 9 for Mazda part numbers.
Table 9: Timing Chain Guide Part #s
Description Mazda Part #
Fixed Guide LF01-12-614
Tensioner Guide LF01-12-671
6.8. Valves
a. OE valves must not be modified (including reshaping); see Table 10 for Mazda part numbers.
le 10: Valve Part #s
b. Valve location or angle must not be moved.
c. Valve guides may not be replaced.
d. Valve job measurements must be as follows:
1. Intake 35 top 45 seat 65 bottom 77 bottom seating angle width is 1.0mm
2. Exhaust 40 top 45 seating to radius seating angle width 1.2 mm.
3. Valve stem installed height must be per the Mazda Factory Service Manual.
4. Valve stem seals must be OE.
6.9. Valve Springs
a. Mazda Motorsports’ competition valve springs (part # 0000-01-5319-SP) are required.
6.10. Intake Manifold
a. OE intake manifold (Mazda part # LF9G-13-130B) is required; no modification is permitted (e.g., no material may be added or removed; no
painting or coating on the exterior or interior permitted).
b. All air entering the engine must pass through the throttle body and metered by the mass airflow sensor.
c. Removal of these factory EGR components is permitted: Valve, crossover pipe, coolant lines (EGR DELETE KIT 0000-06-5447)
d. If factory EGR components are removed, the following ports must be blocked:
1. Intake manifold cross over pipe port.
2. Cylinder head cross over pipe port.
3. EGR valve port on back of cylinder head.
6.11. Intake System
a. Cars must replace OE air box with the Mazda competition cold air intake kit (part # 0000-06- 5150-KT); no modification (e.g., ducting or
baffling of air, venturi cones) to the cold air intake kit is permitted.
b. No alteration to the intake tube length, diameter, or shape is permitted.
c. The air filter supplied in the Mazda Motorsports competition cold air intake kit may be refreshed
with the Mazda Motorsports’ competition air filter (part # 0000-06-5204).
6.12. Fuel System
a. Fuel must comply with SCCA GCR section 9.3.25
b. OE fuel pump (Mazda part # LFG1-13-350) is required; no modification is permitted.
c. It is permitted to remove the unleaded fuel restrictor from the filler neck. (GCR 9.3.26)
d. Mazda Motorsports’ competition fuel rail that includes fuel pressure gauge, and fuel sampling test port and hose kit (part #
0000-06-5207) is optional.
1. Fuel pressure sensor integrated into the required AIM data acquisition system is required. It must be operational and able to be
viewed when pulling a competitor on track data.
2. The addition of a switch or jumper located in the under-hood fuse box is allowed to acti- vate the fuel pump. This modification may
serve no other purpose.
3. One operational fuel sample test port is required. Fuel sample test ports shall be made from dry break fuel rated quick disconnects.
No other style of fuel sample test port is allowed (e.g., Schrader valves).
4. No other modifications permitted.
e. OE fuel pressure regulator (Mazda part # LFB6-13-280) is required.
1. Vehicle must run between 54 and 63 PSI of fuel pressure.
f. OE injectors (Mazda part # L3G5-13-250) are required; no modification is permitted.
1. Flow rates for the injectors must fall within the factory tolerance of 204-216ml (204-216 cc, 12.5-13.1 cu in/minute).
6.13. Lubrication System
a. OE engine oil filter is required; no substitutions permitted.
b. OE oil pump PT# L310-14-100J is required and no modifications are permitted.
c. Mazda Motorsports’ competition oil cooler adaptor kit with lines (part # 0000-01-5100KT) is required; no modification is
permitted.
d. Oil pressure sensor integrated into the required AIM data acquisition system is required. It must be operational and able to be
viewed when pulling a competitor on track data.
e. Oil and lubricants are unrestricted.
6.14. Engine Control Unit (ECU)
a. Reference penalties for non-compliance of the Spec ECU flash in Section 21 below. Modifica- tion or attempted modification of
the Spec ECU flash will result in a 12-month suspension from competition and $1,000.00 fine.
b. Mazda Motorsports’ competition ECU (part # 0000-01-5379) is required; serial number must be visible; external or internal
modification is not permitted.
c. ECU calibrations and inputs must not be modified.
d. OE engine electrical harness (part # NH18-67-020A) is required; no modification is permitted.
e. OBDII diagnostics port must be operational in all cars.
1. The check engine light must be operational and perform the function test at start up.
2. The OBDII port must be available at all times (including during the race) for tech officials to install test equipment as necessary.
3. If a competitor uses the OBDII port to power any type of data acquisition system, he/she would be responsible for providing the
splitter cable to plug in both units or unplug the data acquisition system.
f. Instrument panel clusters must be operational and unmodified OE parts.
g. Temporary data acquisition devices may be installed by the sanctioning body for technical compliance.
h. Removal of Mazda ECU insulator PT# LFG1-13-3C1 is permitted (diagram below)
6.15. Miscellaneous
a. The factory air conditioning system and all associated lines, compressor, condenser and evap- orator must be removed.
1. Once the AC compressor is removed, the OE AC pulley delete kit (Mazda part # LF17-15- 940E) is required.
b. Serpentine belt Gates PT# 6PK-2170 or same size equivalent is required.
7. Exhaust
a. OE exhaust manifold and OE heat shield must be replaced with Mazda Motorsports’ competi- tion part # 0000-06-5407-NC; no modification
is permitted (e.g., internal or external wraps, coatings, paints, metal treatments, thermal barriers etc.).
b. OE exhaust system must be replaced with Mazda Motorsports’ competition part # 0000-06- 5427-NC; no modification is permitted (e.g.,
internal or external wraps, coatings, paints, metal surface treatment, thermal barriers etc.).
c. The forward oxygen (O2) sensor (OE Lambda Sensor) must remain in the factory location and in full working order. Mazda Motorsports’
competition O2 sensor installation kit wiring extender (part # 0000-10-5320) is permitted.
d. The secondary post catalytic oxygen (O2) sensor must be removed.
e. Heat shielding
1. OE heat shield protecting ABS unit from header may not be removed or modified.
2. OE muffler heat shield may not be removed or modified.
3. It is permitted to wrap the exhaust pipe from the mid connection flange to the muffler.
(see red arrows in picture below)
4. Use of heat shielding material on transmission tunnel to replace OE heat shielding is permitted. OE heat shielding
must be removed from transmission tunnel. (see diagram below)
8. Cooling System
(cooling system
checklist)
a. Mazda Motorsports’ competition radiator and oil cooler assembly (part # 0000-01-5504-CR) is required (e.g., OE is not
permitted).
b. The radiator using the OE mounting brackets must be installed in its original location.
c. The oil cooler may not be moved or altered from the pre-assembled mounting location.
d. Radiator ducting may be placed on each side of the radiator tanks and the undertray to force air through the radiator fins. The
gap between the top and sides of the radiator may be sealed but shall not perform any other function.
e. The unmodified OE cooling fan must be maintained in full working order and mounted in the stock location. Axillary control of
the radiator cooling fan may be added to activate the fan independent of the ECU, OE control of the fan must remain intact.
f. Thermostats may be modified, removed or replaced.
g. The OE water pump (Mazda part # 1F70-15-100) is required; no modification is permitted.
h. The OE water pump pulley (Mazda part # L327-15-131) is required; no modification is permitted.
i. Engine cooling system hoses and clamps may be substituted.
j. The heater core may be removed along with HVAC evaporator core including all associated hard pipes and hoses. This is to include
OE water to oil cooler lines as well as throttle body coolant lines. (Rear coolant pipe 0000-01-5514, bottom coolant pipe 0000-
01-5515)
k. The OE engine coolant expansion tank may be replaced with any aftermarket part but and must not serve another purpose.
9. Clutch, Pressure Plate and Flywheel
a. Vehicle may use any combination of the options listed in Table 11 below.
Table 11: Clutch Component Part Numbers
Description Mazda Part #
Mazda Factory Clutch Disc LF05-16-460A
ACT Sprung Clutch Disc 0000-02-5420-AC
ACT Pressure Plate 0000-02-5405-AC
ACT Clutch and PP Kit 0000-02-5004-G6
Mazda Factory
Pressure Plate LF04-16-410A
b. The unmodified pressure plate must be bolted directly to the stock, unmodified flywheel.
c. OE flywheel (Mazda part # LF9G-11-500) is required. Factory Service Manual resurfacing specification is permitted; no
other modification is permitted.
d. Alternate clutch lines are permitted but must not serve another purpose.
e. Clutch components must adhere to the minimum weights listed in Table 12 below:
Table 12: Clutch Component Part Numbers
Description Minimum Weight (lb.)
Clutch disc 3.5
Pressure Plate 9.4
Flywheel 15.80
10. Transmission
a. OE 2006-2015 6-speed gearbox and 4.10 final drive ratio are required.
b. No modification of the internal parts and ratios are permitted except the installation of the unmodified parts contained in the Mazda
Motorsports MX-5 transmission upgrade kit (part # 0000-02-5700).
c. Mazda Motorsports Competition gear set 0000-02-6000 is allowed. Gear ratios are as follows: 1st - 3.82; 2nd - 2.26; 3rd - 1.64;
4th - 1.18; 5th - 1.00; 6th - 0.83/0.79. There are two (2) production 6th gears; either one is permitted.
d. Alternate shift knobs are permitted.
e. Nomex or aftermarket fireproof shift boots are permitted. Removal of the factory rubber shift boot is not permitted.
f. No treating, coating, polishing or modification of any transmission or components are permitted.
g. Fluids and/or lubricants may be substituted with any lubricant.
h. Updating or backdating of transmissions from 2006–2015 is permitted; unmodified OE shifters must be retained. The use of short throw
shifters is prohibited.
i. An single inspection hole (not to exceed 1.5” in diameter) in the bottom of the bell housing is permitted for the sole purpose of technical
inspection of the flywheel. It is permitted to plug or tape over theat hole.
j. Transmission cooler(s) are permitted.
11. Differential
a. Only the Following differentials are allowed.
1. Mazda Motorsports, unmodified, Torsen limited slip differential – 0000-02-5564
2. OE, unmodified, limited slip differential - Mazda part # MS03-27-200B
3. OE, unmodified, open differential are permitted.
b. RX-8 differential mounting bracket (Mazda part # F151-39-730B) is permitted.
c. Mazda Comp diff bushings 0000-04-5510 is permitted (MX-5 diff mount)
d. Polishing, metal treatment or coating of differential or axle components are not
permitted.
e. Removal of metal/rubber isolator on the pinion flange is permitted.
f. Differential cooler(s) are permitted.
12. Suspension and Steering: Suspension
Modifications are limited to the addition of the Mazda Motorsports Spec MX-5 kit; details are as follows (including all
modifications permitted):
a. OE control arms are required; no modification is permitted.
b. Mazda Motorsports’ TSB MX-5-002 must be followed re: the rear shock thread protector found in the “Spec MX-5: Four Pillars”
page on MazdaMotorsports.com. The thread protector must measure 1.250”. (The TSB will not be applicable to the supply from
Mazda Motorsports received after 7.15.2020 as they will have the updated thread protector.)
c. Anti-roll bar links may be replaced with Mazda part # 0000-04-5597-KT
1. Cockpit adjustability is not permitted.
d. Mazda Motorsports’ competition sway bars are required, mounting guidelines:
1. Metal shims up to 1/8” total thickness are permitted between each anti-roll bar mount shackle and the stock mounting
point on the chassis.
2. One end of the sway bar(s) may be disconnected as a suspension tuning aid.
3. The bar must remain in place and be solidly attached to the suspension on one end.
4. Sway bar end links must be installed on the unmodified stock attachment points.
e. Camber, caster, and toe are unrestricted within the limits of the unmodified factory adjust- ments in conjunction with Mazda
Motorsports front offset bushing (part # 000-04-5407-NC).
f. Minimum ride height is unrestricted.
g. Nuts & bolts may be replaced by similar items performing the same fastening function(s).
h. Relocation or reinforcement of any suspension parts or mounting points is not permitted, with the following exceptions:
1. Addition of spacers or washers on a horizontal plane is permitted at the rear lower shock mount to the spindle per the
shock installation instructions.
2. Updating to RX-8 rear toe link and rear trailing arm is permitted. See Table 13 below.
Table 13: Permitted RX-8 Trailing Arm and Toe Link Part #s
Description Mazda Part #
RX-8 Trailing Arm F189-28-200A
RX-8 Toe Link F189-28-45XA
i. OE power steering pump with pulley (Mazda part # NE51-32-650D) is required; Mazda Motor- sports Power steering flow
restrictor PT#- 0000-04-5532 is permitted; no other modification is permitted.
j. OE power steering rack (Mazda part #: NE51-32-110C) is required; no modification or reloca- tion is permitted.
k. Factory power steering reservoir may be replaced.
l. Wheel center caps must be removed.
m. All chassis, structural and electrical repairs must follow factory procedures, specifications, and dimensions as described in the
applicable service manual. Reinforcement (e.g., seam welding, material addition, etc.) is not permitted.
n. Steering lock mechanisms must be removed.
o. The distance from the outside of the wheel rim to outside of the opposing wheel rim for both the front and rear of the vehicle
must not exceed 69.5”.
I. The distance Measurement is obtained by measuring the distance between the wheel lips by going through
the wheel spokes at the bottom of the wheel at its widest point via tape measure. (Measure the outside wheel
lip of one wheel to outside wheel lip of the other wheel on same axle.)
p. Mazda Motorsports’ competition rear toe link (part # 0000-04-5426) is permitted; no modification is permitted.
q. Mazda Motorsport’s Spec MX-5 Suspension Kit includes the items set forth in Items in Table
14. seen below are components within this kit. No substitutions or modifications of parts are permitted. The
unmodified kits must be used in their entirety, except as specified.
Table 14: Spec MX-5 Suspension Kit (All parts are required; no modification is permitted.)
Description Location Mazda Part #
Shocks Front 0000-04-5291-SA
Rear 0000-04-5292-SA
Springs Front 0000-04-9700-08
Rear 0000-04-9400-07
Helper Springs Front/Rear 0000-04-9926
Front Penske
Mount Kit Front 0000-04-5359
Rear Penske
Mount Kit Rear 0000-04-5358
Sway Bar Kit Front and Rear 0000-04-5306-EB
Offset Bushings Front 0000-04-5407-NC
13. Hubs
a. OE RX-8 front hub (Mazda part # F189-33-04X) may be substituted in place of the OE Miata 2006-2015 front hub.
b. Mazda Motorsports’ competition RX-8 rear hub upgrade kit (part # 0000-04-5811-KT) may be substituted in place of the OE MX-
5 rear hubs; this unmodified kit must be used in its entirety.
c. OE RX-8 rear uprights, bearings, hubs, and hybrid axel may be used in place of OE MX-5 parts.
14. Brakes
a. OE brake rotors must be used and adhere to the specifications below in Table 15.
Table 15: Brake Rotor Dimensions
Location Diameter Notes
Front 290mm (11.4”) Vented
Rear 280mm (11.0”) Solid
Front backing plates/dirt shields may be removed.
(see see red arrow in diagram below)
b. Rear backing plates/dirt shields may be removed.
(see red arrow in diagram below)
c. Brake lines may be replaced with competition braided steel lines; option: Mazda Motorsports’ part # 0000-03-5212.
d. The Factory ABS system must remain intact, unmodified, and in full working order.
e. Brake slider pin may be used in either/both front location B25D-33-694. (This prevents a stuck sliding caliper due to the rubber
grommet)
f. Parking brake mechanisms and actuating components may be removed.
g. Brake fluid is unrestricted.
h. Mazda Motorsports’ competition brake duct kit (part # 0000-03-5301) is permitted.
i. The forward vertical inner fender panels may be modified to fit the brake kit hose to the fog light openings but may not be
modified to serve any additional purpose.
j. Mazda Motorsports’ competition brake pads are required; see eligible brake pad compounds in Table 16. No other brake pads
are permitted.
Table 16: Brake Pad part numbers
Pad Style Mazda Part # Notes
Front Pad 0000-03-5104-SP RST-3 compound
Rear Pad 0000-03-5116-29 RSL-29 compound
15. Wheels
The following unmodified wheel options below in Table 17 are permitted for use.
Table 17: WHEELS
Description Color Mazda Part #
17x7” OE Wheel Gun Metallic 99656-47070
17x7” OE Wheel Silver 99656-77070
Mazda Motorsports’ Competition MX-5 Wheel Gun Metallic 0000-04-5706-GM
Mazda Motorsports’ Competition MX-5 Wheel Silver 0000-04-5706-SL
a. Wheels may be painted.
b. Aftermarket (any) wheel studs and lug nuts are permitted., provided that a minimum of two he threads must protrude
beyond the lug nut with the wheel installed with a minimum of two (2) full threads showing; Wheel studs may not be gun
drilled.
c. Wheel spacers are not permitted.
16. Tires
a. Dry tires: Toyo RR P235/40/ZR17
b. Wet tires: Toyo RA1 P235/40/ZR17.
17. Electrical Equipment
a. OE ignition coils (Mazda part # L3G2-18-100B) are required; no modification is permitted.
b. Mazda’s competition spark plugs (part # 0000-10-R7IX-11) are required; no modification is permitted.
c. The crankshaft position sensor and crankshaft pulley relationship must be as specified in the 2006- 2015 MX-5 Factory Service Manual.
d. One of the two OE alternators (Mazda part # LF9H-18-300R-OA, L3P9-18-300D) is required; no modification is permitted.
e. The alternator must not be externally regulated or disabled in any way other than by the OE
production ECU/wiring circuit and master kill switch.
f. The electronic control module (ECM) control circuit for alternator charging must be OE - unmodified and operational.
g. One of the two OE alternator drive pulley part # AJ51-18-W10 (60mm), Part# L813-18- W11(55mm) is required; no modification
is permitted.
h. All sensors related to engine operating parameters must be used and must be stock, unmodi- fied Mazda parts for the correct year
of the vehicle on which they are installed.
i. Any and all sensors and their respective locations, mounts, and wiring harness leads may not be altered except as elsewhere in this
rule set. e Spec-MX-5 rules.
j. Any sensors required for non-OE gauges must be in addition to the Mazda sensors.
k. All alternate gauge and sensors must have independent wiring. Splicing, tapping, or altering
of the factory engine wiring harnesses is prohibited with the exception of adding an
aftermarket tachom- eter/shift light as follows:
1. It is permitted to splice into the yellow wire with the black stripe (pin 2BA - Ignition
Coil 1 control circuit) in the engine harness to obtain the tachometer signal for an
aftermarket tachometer or shift light.
2. Splicing must be done within 5” of the ECU.
l. Data acquisition’s sensor(s) may be added, provided they do not require splicing or
alteration to the factory engine wiring harness.
m. Batteries
1. Batteries may be replaced with those of an alternate manufacturer, provided they are of
similar amp-hour capacity, and size, including lead acid or AGM.; lLithium batteries are not
permitted.
2. Batteries must weigh no less than 18.0lb and no more than 35.0lb
3. Additional battery hold-down devices are recommended.
4. Battery MUST be moved from the original location to the passenger side
in the upper trunk area in front of the tail lamp. This will require the use
of a bulkhead that separates the driver / passenger compartment
completely from the trunk and the battery location. See section 5.I for
reference.
18. Roll Cage
a. Roll cage must adhere to SCCA’s current GCR Section 9.4 for Touring 4 cars; with the following exceptions:
1. One tube not to exceed 1.75” in diameter may be added which extends from the door bars to the rocker panel on each side.
The landing plate for this tube can be no longer than 5” in length. The landing plates must be centered between the front
and rear landing plates for the lower NASCAR or X brace bar.
2. Main hoop mounting plates may be on multiple planes; however, they must not be greater than 19” on any side.
b. Playboy MX-5 Cup car cages manufactured by Racing Cages, Inc. with the official serial number plate on the main hoop are
allowed to retain the lower door bar and two 3” attachment points to the rocker panel on both the driver’s side and passenger
side. No additional seam welding or lengthening of the original attachment points is allowed.
19. Safety
a. An electrical master (“kill”) switch is required. See current GCR Section 9.3 Master Switch.
b. Vehicle must be equipped with a driver’s restraint system meeting the specifications of current GCR Section 9.3 Drivers
Restraint System.
c. Installation of a fire extinguisher or fire system is required. See current GCR 9.3 Fire System.
d. Vehicle must have a driver’s side window safety net complying with current GCR Section 9.3 Window Safety Nets. Nets must be
mounted to provide protection in the event the driver’s door opens.
20. Data
Acquisition
1 A technical evaluation process for cars is available from the Series. Part of this process is the required download of AiM Data files after
each timed session (Qualifying 1 & 2, Races 1 & 2). Within 30 minutes of each timed session end, all Series Competitors MUST send
the AiM Data file (.XRK) for all timed laps of that session to the secure email address (data@specmx-5.com), where data will be
reviewed by AiM directly. Failure to adhere to this guideline from the Series, or having non- functioning data, may be grounds for
penalty or disqualification by the Series.
a. Vehicle must be equipped with current generation AiM data acquisition system (configurable in Race Studio 3) that can provide
on track data to AiM race studio 3. The data acquisition system may only read the OBDII/ECU data stream. It is not permitted
to alter/manipulate data to and from the ECU. The AiM system may be utilized to trigger a switch I.E., cooling fans or diff cooler
pumps but must be wired via a separate analog circuit.
Refer to Section 17: Electrical Equipment above for installation requirements.
b. The connection at the OBDII port for the AiM system may be made in either one of two ways:
1. Through a dedicated OBDII AiM adaptor.
2. By direct wiring to the back of the OBDII port within 3” of the ODBII connector.
c. Fuel pressure datalogging is required.
d. Oil pressure datalogging is required.
e. All cars must run the latest AIM Data Logger Spec MX-5 ECU Protocol
21. Mandatory
Video
Camera
Cars running in Spec MX-5 must have a functioning video recorder/camera during all qualifying and race sessions as described in 9.3.11.
Upon request by an SCCA official, competitors must provide their video recording/data, which may be used by the SCCA for any
purpose including but not limited to rule enforcement and marketing. Failure to comply with a video request from an official, or
having a non-functioning video recorder/camera may will be grounds for penalty or disqualification.
22. Parts
Confiscation
a. Tech officials may confiscate competitors’ parts for the purpose of verification of tech compliance.
23. Penalties Clarification – Non-Compliant Parts
Level Infraction Penalty
1 Non-compliant modification to any of the spec
parts, engine components, ECU/Elec- tronics or
modification to the chassis.
May suspend the driver (i.e. suspend) of the non-
compliant Spec MX-5 from competing in SCCA
events for the 12 months following the suspension.
A level 1 infraction carries a $1,000 fine.
2
Non-compliant modification to the suspen- sion or
drivetrain outside of level one infrac- tions: engine,
fuel system, charging system, exhaust, and intake
system.
May suspend the driver (i.e. suspend) of the non-
compliant Spec MX-5 from competing in SCCA
events for the 6 months following the suspension.
A level 2 infraction carries a $500 fine.
3 Use of an unauthorized or non-compliant part,
engine component, ECU/Electronics or chassis or
chassis part.
May suspend the driver (i.e. suspend) of the non-
compliant Spec MX-5 from competing in SCCA
events for the 12 months following the suspension.
A level 3 infraction carries a $1,000 fine
4
Non-compliance (non-modification such as
incorrect part)Use of an unauthorized or non-
compliant for any of the suspension or drive- train
part or component outside of level one infractions:
engine, fuel system, charging system, exhaust, and
intake system.
May suspend the driver (i.e. suspend) of the non-
compliant Spec MX-5 from competing in SCCA
events for the 6 months following the suspension.
A level 4 infraction carries a $500 fine

SMX Committee) OE versus OEM Definitons

#36608 from Spec Mazda (SM/SMX · Rule change · TB 24-09 (2024-09 Fastrack)

Summary

wordingSMX Mazda Miata OE versus OEM definitions clarified in GCR Section 9.1.7.1.

As printed in Fastrack

In GCR, Replace Section 9.1.7.1 Spec MX-5 (SMX) with the attached:

SMX Committee) Shifter Bushing

#36611 from Spec Mazda (SM/SMX · Rule change · TB 24-09 (2024-09 Fastrack)

Summary

wordingSM and SMX shifter bushing rules clarified: alternate bushing at shift lever bottom now allowed.

As printed in Fastrack

In section 9.1.7.1.D.6.3., add the following:
"k. Alternate shifter bushing located at the bottom of the shift lever is allowed."

EP 1275 HP Spridget Level 2 Only

#36518 from Darryl Saylor · Rule change · TB 24-09 (2024-09 Fastrack)

Summary

fasterHP Sprite and Midget 1275cc and 1098cc Level 2 compression ratio raised to 12.0:1.

As printed in Fastrack

In HP Spec Lines, Austin-Healey Sprite MkI, II, III, IV MG Midget (ALL) - Level 2 - 1275cc, change Notes as follows:
"(Effective 11/1/2024) Compression ratio limited to 11 12.0:1"
In HP Spec Lines, Austin-Healey Sprite MkI, II, III, IV MG Midget (ALL) - Level 2 - 1098cc, change Notes as follows:
"(Effective 11/1/2024) Compression ratio limited to 11 12.0:1"

EP NA Miata Track Width Correction

#36902 from Production Committee · Rule change · TB 24-11 (2024-11 Fastrack)

Summary

wordingEP Mazda Miata front and rear track widths increased to 1516/1534 mm (59.7/60.4 in.) across all generations.

As printed in Fastrack

In EP Spec Lines, Track (F/R) mm/(in.), change as follows:
Mazda MX-5 /Miata 1.6L (-1993) - "1478/1491 (58.2/58.7) 1516/1534 (59.7/60.4)"
Mazda MX-5 /Miata 1.8L (90-97) - "1483/1509 (58.4/59.4) 1516/1534 (59.7/60.4)"
Mazda MX-5 /Miata (94-97) - "1483/1509 (58.4/59.4) 1516/1534 (59.7/60.4)"

T1 Changes to T1 Tires for GT4 and Other Cars

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

Summary

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.

As printed in Fastrack

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"

Show 3 more lines

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)

Summary

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

As printed in Fastrack

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)

Summary

wordingT1 Spec Lines now permits 5.5 inch clutch in Engine Notes.

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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"

SMX E&O SMX Regs 9.1.7.1.D.5.u-.w

#37070 from Greg Amy · Rule change · TB 24-12 (2024-12 Fastrack)

Summary

wordingSMX allows OE instrument cluster relocation for aftermarket dash mounting, with wiring re-routed only; alternate gauges now permitted.

As printed in Fastrack

In GCR, Section 9.1.7.D.5.u-w, change as follows:
"u. Alternate guages and instuments may be added. The original OE instrument cluster must remain unmodified, connected and
functional. However, it may be relocated to allow the mounting of an aftermarket dash such as an AIM. The wiring to relocated
the dash may not be cut or extended, it may only be re-routed. The remainder of teh dashboard or panel must remain intact.
v. Alternate gauges and instuments may be added.
w. Modifications may be made to the foot pedals to improve the comfort and accessibility to the driver; relocation of mounting
points is not permitted.
1. Dead pedal/footrest and heel stop may be added.

Show 1 more lines

w. Instrument clusters must be unmodified parts."

EP Triumph GT6 Adjustments

#37112 from Anthony Parker · Rule change · TB 24-12 (2024-12 Fastrack)

Summary

slowerEP Triumph GT6 switches to three Weber 40 DCOE carbs with 28mm chokes, weight rises 50 lbs to 1990.

As printed in Fastrack

In EP Spec Lines, make the following changes in the "Triumph GT6" spec line:
Carburetor No. & Type: (2): "1.5” 1.75" Auto-type carburetor(s)"
Notes: "Two (2) 1.75” auto-type carburetors @ 1940 lbs. Three (3) Weber 40 DCOE on IR manifold with 28mm chokes @ 1990
lbs. Laycock overdrive, May use 5 speed gearbox w/o overdrive."

T1 Request Ford Performance Darkhorse R in T1

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

Summary

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

As printed in Fastrack

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.

T1 Car Mods for T1 Corvette under line item 1150

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

Summary

wordingT1 Corvette may roll or flatten wheel opening lips for tire clearance; plastic fenders may remove lips if edge thickness matches basic material.

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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."

EP Request to Reduce Weight of BMW 325i/is E30 (84-91) Spec Line

#37119 from Tim Schreyer · Rule change · TB 25-01 (2025-01 Fastrack)

Summary

fasterEP BMW 325i/is E30 (84-91) weight reduced 50–52 lbs across three spec lines to 2150, 2204, 2258.

As printed in Fastrack

In EP SPEC LINES, BMW 325i/is (E30) (84-91), change Weight as follows:
"2200 2150
*2255 2204
**2310 2258"

T1 T1 Parity Compared to GT4

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

Summary

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.

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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)

Summary

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.

As printed in Fastrack

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"

EP Effective date for Jan 2025 GCR updates

#37654 from Doug Piner · Rule change · TB 25-02 (2025-02 Fastrack)

Summary

slowerEP BMW Z3 2.5L requires 52mm flat plate intake restrictor; Z3 2.8L 55mm; 328i/is E36 58mm; 328i/ci E46 58mm; 325i/is E46 56mm; 325i/is E36 56mm; 325is M-Technic 56mm.

As printed in Fastrack

In EP Spec Lines, add to Notes as follows:
BMW Z3 2.5LL "(Effective 2/21/2025) 52mm Flat Plate Intake Restrictor is required."
BMW Z3 2.8L (97-00): "(Effective 2/21/2025) 55mm Flat Plate Intake Restrictor is required."
BMW 328i/is E36 (96-99): "(Effective 2/21/2025) 58mm Flat Plate Intake Restrictor is required."
BMW 328i/ci E46 (01-06): "(Effective 2/21/2025) 58mm Flat Plate Intake Restrictor is required."
BMW 325i/is E46 (01-06): "(Effective 2/21/2025) 56mm Flat Plate Intake Restrictor is required."
BMW 325i/is E-36 (92-95): "(Effective 2/21/2025) 56mm Flat Plate Intake Restrictor is required."
BMW 325is M-Technic (1994): "(Effective 2/21/2025) 56mm Flat Plate Intake Restrictor is required."

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

EP Request Competition Adjustment to BMW Z3 2.5L

#37120 from Tim Schreyer · Rule change · TB 25-01 (2025-01 Fastrack)

Summary

slowerEP BMW Z3 and 3-series models get smaller intake restrictors: Z3 2.5L to 52mm, Z3 2.8L to 55mm, 328i to 58mm, 325i to 56mm.

As printed in Fastrack

In EP Spec Lines, change Notes as follows:
BMW Z3 2.5LL "(Effective 3/1/2025) 56mm 52mm Flat Plate Intake Restrictor is required."
BMW Z3 2.8L (97-00): "(Effective 3/1/2025) 59mm 55mm Flat Plate Intake Restrictor is required."
BMW 328i/is E36 (96-99): "(Effective 3/1/2025) 62mm 58mm Flat Plate Intake Restrictor is required."
BMW 328i/ci E46 (01-06): "(Effective 3/1/2025) 62mm 58mm Flat Plate Intake Restrictor is required."
BMW 325i/is E46 (01-06): "(Effective 3/1/2025) 60mm 56mm Flat Plate Intake Restrictor is required."
BMW 325i/is E-36 (92-95): "(Effective 3/1/2025) 60mm 56mm Flat Plate Intake Restrictor is required."
BMW 325is M-Technic (1994): "(Effective 3/1/2025) 60mm 56mm Flat Plate Intake Restrictor is required."

EP Interpretation of Production Rules on Mirrors

#37235 from Lawrence Slivinski · Rule change · TB 25-03 (2025-03 Fastrack)

Summary

wordingEP, FP, HP: interior or exterior mirrors meeting rule 9.3.36 now permitted.

As printed in Fastrack

In GCR, add new rule as Section 9.1.5.E.10.f:
"Any interior or exterior mirror(s) that meets rule 9.3.36 may be used."

EP Weight Reduction for Honda S2000

#37466 from Michael Unger · Rule change · TB 25-03 (2025-03 Fastrack)

Summary

fasterEP Honda S2000 1997cc base loses 75 lbs to 2375; 2157cc base loses 60 lbs to 2450.

As printed in Fastrack

In EP, Spec Lines make the following weight changes:

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

EP Mazda 1999 Miata 1.8L

#37488 from Joe Carr · Rule change · TB 25-03 (2025-03 Fastrack)

Summary

fasterEP Mazda MX-5/Miata 99-05 minimum weight drops to 2100 lbs, 2153 lbs with power adder, 2205 lbs with two adders.

As printed in Fastrack

In EP Spec Lines, make the following weight change:
Mazda MX-5 /Miata (99-05):
"2150 2100
*2204 2153
**2258 2205"

T1 Correct and make new T1 BOP adjustments.

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

Summary

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.

As printed in Fastrack

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"

Show 5 more lines

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”

EP Request for Classification of Chevrolet Spark

#37755 from Kristian Smith · Rule change · TB 25-04 (2025-04 Fastrack)

Summary

cars addedChevrolet Spark 16-22 classified HP Pre at 1850 lbs minimum weight, fuel injected, 1399 cc.

As printed in Fastrack

In HP Spec Lines, classify the Chevrolet Spark (16-22):

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

EP Request to Lower Ford Festiva Minimum Weight to 1600 LBS

#37939 from Doug DeRonne · Rule change · TB 25-04 (2025-04 Fastrack)

Summary

fasterHP Ford Festiva 88-93 minimum weight drops to 1600 lbs, variants to 1640 and 1680 lbs; compression ratio raised to 11.0:1.

As printed in Fastrack

In HP Spec Lines "Ford Festiva (88-93)" change as follows:
Weight:
"1700 1600
*1743 1640
**1785 1680"
Notes:
"Compression ratio limited to 10.5 11.0:1. Valve lift limited to .450”."

T1 Cadillac CT4-V Blackwing

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

Summary

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

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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)

Summary

wordingT1 BMW E46 M3 permits BMW #GS7D36SG aftermarket sequential transmission in SL# 1060 and 1070.

As printed in Fastrack

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

SMX Clarify Tire Marking Regs

#38004 from Greg Amy · Rule change · TB 25-05 (2025-05 Fastrack)

Summary

wordingSMX Toyo RR P235/40/ZR17 tire rules clarified: one set per weekend, marking after first session, damage replacement procedures revised.

As printed in Fastrack

In GCR, Section 9.1.7.1.D.16.c., change as follows:
"1. Cars in SMX are limited to running 1 (one) new (sticker) set, used tires or any of those combinations, of class specified Toyo
tires (Toyo RR P235/40/ZR17) per regular season Hoosier Super Tour event weekend during qualifying and races (not including
any test day sessions). Before the first dry qualifying or race (if rain in qualifying) session competitors will supply four Toyo RR
P235/40/ZR17 tires for marking to use during the entire weekend. Class specified rain tires will not be marked. SMX cars are
limited to one set of Toyo RR P235/40/ZR17 per Hoosier Super Tour event weekend for all dry qualifying and race sessions. This
limitation does not include testing or practice sessions. Approved rain tires will not be required to be marked.
2. A mandatory impound for all SMX competitors is required after the first dry qualifying or race (if rain in qualifying) session. It

Show 11 more lines

is the competitor’s responsibility to ensure their tires are marked prior to going on track for the next session. A mandatory
impound for all SMX competitors will occur after the first dry qualifying or race session. All tires will be marked for the remainder
of the race weekend. It is the competitor’s responsibility to report to impound and ensure their tires are marked prior to leaving
impound.
3. If a competitor damages a tire or wheel, and there is a safety concern, the competitor must find the Hoosier Super Tour Series
Tech Chief or SMX CCC, if assigned, for inspection. At the direction of the Hoosier Super Tour Series Tech Chief or SMX CCC, the
compet- itor will be allowed to substitute alternate used tire(s) to replace the damaged tire(s). New tires are not an option as a
replacement tire for a damaged tire. If a competitor damages a tire or wheel and there is a safety concern, the competitor must
find the Hooseir Super Tour Series Tech Chief or SMX CCC, if assigned, for inspection. At the discretion of the Hoosier Super Tour
Series Tech Chief of SMX CCC the competitor may be allowed to substitute alternate used tires(s) to replace the damaged
tire(s). New tires are not an option as a replacement tire for a damaged tire."

SMX SMX Data Submission Timeframe

#38039 from Jason Fichter · Rule change · TB 25-05 (2025-05 Fastrack)

Summary

wordingSMX data submission deadline extended from 30 to 60 minutes after each timed session.

As printed in Fastrack

RM 25-04 Please update the data acquisition timeframe in GCR section 9.1.7.1.D.20
"20. Data Acquisition
1. A technical evaluation process for cars is available. Part of this process is the required download of AiM Data files after each
timed session (Qualifying 1 & 2, Races 1 & 2). Within 30 60 minutes of each timed session end, all competitors MUST send the
AiM Data file (.XRK) for all timed laps of that session to the secure email address (data@specmx-5.com), where data will be
reviewed by AiM directly. Failure to adhere to this guideline, or having non-functioning data, may be grounds for penalty or
disqualification."

T1 Reduce E92 M3 Minimum Weight to 3050

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

Summary

fasterT1 BMW M3 E92 minimum weight reduced to 3300 lbs.

As printed in Fastrack

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)

Summary

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

As printed in Fastrack

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.**"

SMX SMX Data Submission - Penalties

#38248 from Kathy Barnes · Rule change · TB 25-06 (2025-06 Fastrack)

Summary

wordingSMX drivers must submit data acquisition files on time or face suspension and $250 fine.

As printed in Fastrack

In GCR, Section 9.1.7.1.23 add new level 5 infraction as follows:
Level: "5"
Infraction: "Failure to successfully submit (received by data@specmx-5.com) data acquisition file to data@specmx-5 per the
timeframes outlined in GCR section 9.1.7.1.20."
Penalty: "May suspend the driver (i.e. suspend) of the Spec MX-5 that failed to submit data on time or at all from competing in
SCCA events for the 3 months following the suspension.
A level 5 infraction may carry a $250.00 fine."

EP Base Weight Adjustment for H-Production X1/9 Spec Lines

#38255 from Matthew Brannon · Rule change · TB 25-06 (2025-06 Fastrack)

Summary

fasterHP Fiat X-1/9 base weights reduced 50–53 lbs across 1300 and 1500 spec lines.

As printed in Fastrack

In HP Spec Lines, change Weight as follows:
Fiat X-1/9 & Bertone1500: “1790 1740 *1835 1784 **1880 1827”
Fiat X-1/9 1300: “1650 1600 *1691 1640 **1733 1680”
Fiat X-1/9 1300: “2060 2010”
Fiat X-1/9 1500: “1950 1900”

SMX Committee) SMX Penaly Clarification updated language

#38337 from Spec Mazda (SM/SMX · Rule change · TB 25-06 (2025-06 Fastrack)

Summary

wordingSMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fine; level 2 and 4 may carry $500 fine.

As printed in Fastrack

In GCR, Section 9.1.7.1.23. change as follows:
Rename as follows: "Penalties Clarification – Non-Compliant Parts SMX Penalty Guidelines"
Change the Penalty language for level 1 to the following: "A level 1 infraction carries may carry a $1,000 fine."
Change the penalty language for level 2 to the following: "A level 2 infraction carries may carry a $500 fine."
Change the penalty language for level 3 to the following: "A level 3 infraction carries may carry a $1,000 fine."
Change the penalty language for level 4 to the following: "A level 4 infraction carries may carry a $500 fine."

EP BMW Z4 update

#38490 from Bryce McGuire · Rule change · TB 25-07 (2025-07 Fastrack)

Summary

slowerEP BMW Z4 03-05 restricted to 52mm flat plate intake restrictor.

As printed in Fastrack

In EP Spec Lines, BMW Z4 (03-05), add to Notes the following:
“52mm Flat Plate Intake Restrictor.”

EP EP Fiat 124 Spider Competition Adjustment Request

#38498 from John Baucom · Rule change · TB 25-07 (2025-07 Fastrack)

Summary

fasterEP Fiat 124 Spider 1600 & 2000 weight drops 50 lbs to 2000; carburetors gain 2mm chokes to 36mm.

As printed in Fastrack

In EP Spec Lines, Fiat 124 Sport Spider 1600 & 124 Spider 2000, change as follows:
Weight: "2050 2000"
Carburetor No. & Type: "(2) Weber 40 IDF-40IFI, (2) Solex C40P116, 34 36mm choke(s) req’d, (2) Weber 45DCOE w/ 34 36 mm
choke(s) on I.R. manifold or fuel injection."

EP HP Plymouth Arrow spec omission

#38995 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)

Summary

wordingHP Plymouth Arrow transmission max speeds clarified to 4 or 5.

As printed in Fastrack

In HP Spec Lines, Plymouth Arrow (76-80), add the following wording to Trans. Speeds(max):
"4 or 5"

EP Add Wheel Diameter to Appendix G

#39008 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)

Summary

wordingEP, FP, HP wheel diameter added to Appendix G as absolute maximum specification.

As printed in Fastrack

In Appendix G.2.3, change as follows:
"Rim width and diameter are is absolute maximums."

EP Add TB ID tolerance to general Prod rules

#39009 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)

Summary

wordingEP, FP, HP throttle body inside dimensions must remain stock with +/-.25mm tolerance; butterfly dimensions stock in FP, HP only.

As printed in Fastrack

In GCR, Section 9.1.5.E., change as follows:
9.1.5.E.1.b.4: "The inside dimensions of the throttle body casting/housing (as measured at the throttle butterfly) must remain
stock (tolerance of +/-.25mm), but the throttle body can otherwise be ported and polished."
9.1.5.E.2.b.4: "The inside dimensions of the throttle body casting/housing and all dimensions of the throttle butterfly must
remain stock (tolerance of +/-.25mm)."

EP Please Lower Weight of 280Z

#38871 from Matthew Miller · Rule change · TB 25-09 (2025-09 Fastrack)

Summary

fasterEP Nissan 280Z minimum weight reduced from 2560 to 2400 lbs.

As printed in Fastrack

In EP Spec Lines, Nissan 280Z, change Weight (lbs) as follows:
"(Effective 11/1/2025) 2560 2400
*2624 2460
**2688 2520"

EP Miata Weight Adjustment Follow Up

#38949 from Don Tucker · Rule change · TB 25-10 (2025-10 Fastrack)

Summary

fasterEP Mazda MX-5 1.8L 90-97 weight reduced to 2125 lbs from 2150 lbs.

As printed in Fastrack

In EP Spec Lines, Mazda MX-5 / Miata 1.8L (90-97), Effective 11/1/2025 make the following weight change:
"2150 2125"

EP Weight Break for 1098 Midget / Sprite

#38970 from Kendall Jones · Rule change · TB 25-10 (2025-10 Fastrack)

Summary

fasterHP Austin-Healey Sprite/Midget 1098cc minimum weight drops 80 lbs to 1550.

As printed in Fastrack

In HP Spec Lines, Austin-Healey Sprite/Midget 1098cc, Effective 11/1/2025make the following weight change:
"1630 1550"

EP HP Volvo 142 spec omission

#38994 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)

Summary

slowerHP Volvo 142/142E gains compression ratio limit 12.0:1 and valve lift limit .425".

As printed in Fastrack

In HP Spec Lines, Volvo 142/142E P-1800 Engine, Effective 11/1/2025 add the following wording to Notes:
"Comp. Ratio limited to 12.0:1. Valve lift limited to .425”."

EP HP Mini DOHC 1.6

#38996 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)

Summary

slowerHP Mini Cooper 07-15 valve lift reduced to .390", from .450".

As printed in Fastrack

In HP Spec Lines, Mini Cooper (07-13) (includes 09-15 convertible and 12-15 Coupe), Effective 11/1/2025 make the following
changes to the Notes:
"Compression ratio limited to 11.0:1, Valve lift limited to .450”.390"."

EP Add to Rabbit description

#39019 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)

Summary

wordingFP and HP Volkswagen Rabbit descriptions updated: Convertible changed to Cabriolet in FP; Cabriolet added to three HP engine variants.

As printed in Fastrack

In FP Spec Lines, make the following spec line correction:
"Volkswagen Rabbit (Includes Convertible Cabriolet)"
In HP Spec Lines, make the following spec line correction:
"Volkswagen Rabbit 1588 (Includes Cabriolet)"
"Volkswagen Rabbit 1715 (Includes Cabriolet)"
"Volkswagen Rabbit 1780 (Includes Cabriolet)"

EP Clean-up 9.1.5.E.7e

#39025 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)

Summary

wordingEP, FP, HP: rear drum brake to disc conversion clarified; rotors solid, diameter limited to largest front rotor permitted.

As printed in Fastrack

In GCR, Section 9.1.5.E.7., change as follows:
"e. Cars fitted with rear drum brakes, can convert to rear disc brakes without penalty. Note that the “Brakes Std.” and “Brakes
Alt.” listings on a vehicle’s spec line do not prohibit a car that was fitted with rear drum brakes stock, from converting to rear
disc brakes under this rule. When converting from rear drum brakes to rear disc brakes:
1. Rear brake rotors must be solid and can be no larger in diameter than the largest permitted front brake rotor, as defined on
the vehicle’s spec line.
2. Rear calipers and mounting brackets are unrestricted but must be made of a ferrous or aluminum material. The standard and
alternate brake listings on a vehicle’s specification line, does not prohibit a car that was fitted with rear drum brakes as stock

Show 3 more lines

from converting to rear disc brakes under this rule.
3. The “Brakes Std.” and “Brakes Alt.” listings on a vehicle’s spec line do not prohibit a car that was fitted with rear drum brakes
as stock from converting to rear disc brakes under this rule."

EP Add TB size to Ford Mustang (94-98) Spec Line

#39130 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)

Summary

wordingEP Ford Mustang (94-98) fuel injected throttle body inside diameter specified at 60.

As printed in Fastrack

In EP Spec Lines, Ford Mustang (94-98) add the following to the Fuel Injected Equipped Throttle Body Inside Diameter column:
"60"

EP TR2 Notes E&O

#39180 from Anthony Parker · Rule change · TB 25-12 (2025-12 Fastrack)

Summary

unclearEP Triumph TR2-TR4A allows 5-speed gearbox without overdrive; removes Weber carb and weight specification.

As printed in Fastrack

In EP Spec Lines, Triumph TR2, 3, 3A, 4, 4A, TR4, TR4A, IRS, make the following change to the Notes:
"Front apron assembly may be made of alternate material. Three (3) Weber 40 DCOE on IR manifold with 28mm chokes @ 1990
lbs. Laycock overdrive, may use 5 speed gearbox without overdrive."

EP Balance of Power

#39187 from Jim Simaras · Rule change · TB 25-12 (2025-12 Fastrack)

Summary

slowerEP BMW Z3 2.5L restrictor reduced 52mm to 50mm, weight increased to 2550 lbs base; five other BMW models get smaller restrictors.

As printed in Fastrack

In EP Spec Lines, make the following changes to Restrictors:
BMW Z3 2.5L: "52mm 50mm Flat Plate Intake Restrictor"
BMW Z3 2.8L (97-00): "55mm 53mm Flat Plate Intake Restrictor"
BMW 328i/is E36 (96-99): "58mm 55mm Flat Plate Intake Restrictor"
BMW 328i/ci E46 (01-06): "58mm 55mm Flat Plate Intake Restrictor"
BMW 325i/is (E46) (01-06): "56mm 53mm Flat Plate Intake Restrictor"
BMW 325is M-Technic (1994): "56mm 53mm Flat Plate Intake Restrictor"
BMW 325i/is E-36 (92-95): "56mm 53mm Flat Plate Intake Restrictor"

Show 4 more lines

In EP Spec Lines, BMW Z3 2.5L, change Weight as follows:
"2500 2550
*2563 2614
**2625 2678"

T1 Keep S2000 Classification

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

Summary

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

As printed in Fastrack

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

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)

Summary

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

As printed in Fastrack

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"

Show 38 more lines

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)

Summary

removedT1 BMW M3 E92 (08-13) Spec Line 1090 removed entirely.

As printed in Fastrack

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

EP Request to Update E30 BMW Throttle Body Diameter Verbiage

#39363 from Tim Schreyer · Rule change · TB 26-01 (2026-01 Fastrack)

Summary

wordingEP BMW 325i/is E30 throttle body specified as 60mm in fuel injection notes.

As printed in Fastrack

In EP Spec Line BMW 325i/is E30 (84-91), change Drivetrain Notes as follows:
"Fuel Injection, TB: 60mm"

T1 additional T1 adjustment

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

Summary

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

As printed in Fastrack

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

T1 LS1 into Corvette C6 Spec Line Request

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

Summary

cars addedT1 Corvette C6 LS1/LS6 Spec Line reinstated: 3200 lbs minimum weight, 70mm restrictor required.

As printed in Fastrack

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.