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BoP Lab / Buttonwillow Raceway Park

P + AS + STU + SM at Buttonwillow Raceway Park

No mapCal Club 2024, Cal Club 2023

Track map: sectors and speed trap

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

This track has been raced on 4 configurations (The Circuit, 2.57 mi; 2.92 mi; 1.83 mi; 3.02 mi). Laps on different configurations are not comparable, so only events on the 2.57 mile layout are shown; switch above to see the others.

One run is left out as not that car's own laps (far quicker than the car managed in any other session and than anyone else in its class all week; usually a swapped transponder): William Rasmussen in Cal Club 2025 Fri PM (1:36.912; the car's best in any other session was 2:00.848 and the rest of the class's best all week 1:41.720).

6 laps are left out as timing errors (far too short to be a lap of this track). The rest of those sessions, sectors included, is used.

PosCarDriverClass#LapTheoreticalQualRace5-lap stintConsistencyTrapS1S2S3
1Elan DP02/MazdaJim DevenportP23, 281:32.576 A-P1:32.2841:32.872 B-Q21:33.972 B-R21:35.195 B-R1+1.742 B-R1171.9 A-P25.461 B-Q226.606 A-P40.217 A-P
2Dauntless StohrJohnnie CreanP3, 1351:36.516 B-Q11:36.5161:36.516 B-Q11:39.209 B-R11:40.027 B-R1+1.943 B-R1157.4 B-P25.956 B-Q128.143 B-Q142.417 B-Q1
3Dauntless-Stohr P07dJohn ManfroyP081:37.287 A-R21:36.3391:41.818 A-Q11:37.287 A-R21:39.027 A-R2+2.902 A-R2160.4 A-R226.696 A-R227.257 A-R242.386 A-R2
4Stohr WF1Kevin MitzP131:38.716 A-Q21:38.6671:38.716 A-Q21:39.638 A-R21:40.087 A-R2+0.641 A-R2155.4 A-Q126.934 A-Q228.397 A-Q243.336 A-Q2
5Penton Norma M20FCJoseph MoranP71:39.296 A-Q21:38.8681:39.296 A-Q21:40.832 A-R11:42.328 A-R1+3.544 A-R1149.0 A-Q227.106 B-Q128.111 A-Q143.651 A-Q1
6Mazda Miata (1993)John StottSM451:41.720 B-P1:41.5472:04.563 B-Q13:19.168 B-R1153.3 B-P28.011 B-P29.514 B-P44.022 B-P
7Mazda RX-3Tony RiveraSTU091:50.913 A-Q21:50.8701:50.913 A-Q21:52.737 A-R21:54.126 A-R2+2.638 A-R2135.2 A-Q230.415 A-Q232.456 A-Q247.999 A-Q2
8Mazda Miata (1999)Alan Leukhardt IIISM171:51.297 B-P1:50.8002:06.617 B-Q12:07.598 B-R12:08.347 B-R1+2.314 B-R1120.9 A-Q130.402 B-P32.034 B-P48.364 B-P
9Mazda MiataWhitfield GreggSTU171:51.602 B-P1:51.6022:02.264 B-Q22:01.538 B-R12:02.222 B-R1+1.271 B-R1116.3 A-Q130.652 B-P32.263 B-P48.687 B-P
10BMW M3Wilson PowellSTU771:52.380 B-P1:52.1641:55.401 B-Q11:53.843 B-R11:54.699 B-R1+1.965 B-R1102.6 B-R130.577 B-P32.372 B-P49.215 B-P
11Mazda Miata (1999)Sophia StoreySM65, 1871:53.207 B-P1:52.8252:02.978 B-Q12:02.546 B-R12:02.991 B-R1+1.086 B-R1102.6 B-R130.832 B-P32.705 B-P49.288 B-P
12Mazda Miata (1999)Curtis ZhiSM771:53.375 B-P1:53.3752:02.880 B-Q22:02.884 B-R12:03.224 B-R1+0.505 B-R1102.2 B-Q233.066 B-R135.129 B-Q154.444 B-R1
13Honda S2000Rylan HazeltonSTU491:53.640 B-R11:53.1401:55.834 B-Q11:53.640 B-R11:54.534 A-R2+0.714 A-R2134.8 A-R230.582 B-R132.779 B-R149.779 A-R2
14Ford MustangRoger EagletonAS111:55.849 B-R11:55.5691:56.445 B-Q11:55.849 B-R11:56.324 B-R1+0.678 B-R1108.7 B-R131.659 B-Q133.571 B-R150.339 B-R1
15Ford MustangRoss MurrayAS14, 741:56.314 A-R11:56.0471:56.812 A-Q11:56.314 A-R11:56.660 A-R1+0.887 A-R1135.2 A-R232.070 A-R133.689 A-R150.288 A-R1
16BMW 330Sean LovettSTU371:56.492 A-Q21:56.4261:56.492 A-Q21:57.049 A-R21:57.605 A-R2+1.649 A-R2133.7 A-R231.816 A-Q233.669 A-Q150.941 A-Q2
17Ford Mustang FR500SPratt ColeAS8, 8x1:58.795 B-R11:58.0781:59.911 B-Q11:58.795 B-R11:59.396 B-R1+1.547 B-R1103.3 B-Q132.531 B-R133.997 B-R151.550 B-R1
18Ford MustangMatt LituchyAS301:59.134 B-R11:58.7322:00.395 B-Q11:59.134 B-R11:59.643 B-R1+0.914 B-R1105.1 B-Q132.777 B-R134.259 B-R151.696 B-R2
19Nissan 300ZXJames SlechtaSTU751:59.183 A-Q21:59.1831:59.183 A-Q22:00.458 A-R22:01.009 A-R2+0.921 A-R2132.0 A-Q132.882 A-Q234.528 A-Q251.773 A-Q2
20Mazda MX-5Oscar JacksonSTU1611:59.707 B-R21:58.8881:59.707 B-R21:59.952 B-R2+1.112 B-R2103.9 B-R232.339 B-R234.219 B-R252.330 B-R2
21Mazda RX-7Michael LewisSTU322:00.248 A-R12:00.1792:00.248 A-R12:02.190 A-R2+1.431 A-R2130.4 A-R132.729 A-R134.570 A-R152.880 A-R1
22Ford MustangMichael LoweAS102:00.612 A-R22:00.1262:03.053 A-Q12:00.612 A-R22:02.546 A-R2+4.568 A-R2126.5 A-R132.652 B-R134.913 B-R152.561 A-R2
23Mazda Miata (1991)William Wallis >115%SM1962:00.831 B-Q22:00.6532:00.831 B-Q22:01.805 B-R12:02.063 B-R1+0.492 B-R1102.2 B-Q132.837 B-R134.577 B-Q253.239 B-Q2
24Mazda MiataWilliam Rasmussen 2+ cars >115%SM232:00.848 B-Q22:00.8482:00.848 B-Q22:01.937 B-R12:02.575 B-R1+1.131 B-R1102.9 B-R232.618 B-Q234.761 B-Q253.469 B-Q2
25Mazda MiataEvan Jacobs >115%SM352:01.305 B-Q22:00.8992:01.305 B-Q22:01.800 B-R22:02.068 B-R1+0.298 B-R1103.9 B-R232.898 B-R134.715 B-R153.286 B-Q2
26Mazda Miata (2003)Ryan Busk >115%SM72:01.392 A-Q22:01.3922:01.392 A-Q22:02.555 A-R22:02.854 A-R2+0.519 A-R2124.6 A-R233.152 A-R235.121 A-R253.594 A-Q2
27Mazda Miata (1999)Nathan Del Carmen >115%SM882:01.474 B-Q22:01.3882:01.474 B-Q22:01.948 B-R22:02.308 B-R2+1.139 B-R2101.3 B-R232.746 B-Q234.922 B-Q253.720 B-Q1
28Mazda MX-5Dale ShoemakerSTU522:01.642 B-R22:01.1762:04.115 B-Q12:01.642 B-R22:02.793 B-R2+2.442 B-R2125.9 A-Q232.956 B-R234.983 B-R253.237 B-R2
29Mazda Miata (1999)Nick Leverone >115%SM942:01.650 B-R12:01.2392:01.706 B-Q22:01.650 B-R12:02.204 B-R1+0.855 B-R1120.7 A-Q132.921 B-R234.741 B-Q253.577 B-Q2
30Mazda Miata (1991)Clement Lee >115%SM872:01.753 B-Q12:01.2872:01.753 B-Q12:01.777 B-R12:02.189 B-R1+0.579 B-R1101.4 B-R132.979 B-R134.807 B-R153.501 B-Q1
31Mazda Miatta (1999)William Rasmussen 2+ cars >115%SM232:01.816 A-Q22:01.8162:01.816 A-Q22:02.486 A-R22:02.695 A-R2+0.697 A-R2125.6 A-R233.179 A-R234.870 A-Q253.902 A-Q2
32Mazda Miata (1999)Tyler Vance >115%SM12:01.993 A-Q22:01.9932:01.993 A-Q22:03.785 A-R12:04.163 A-R1+0.882 A-R1119.9 A-R133.194 A-Q135.246 A-Q153.843 A-Q2
33Mazda Miata (2001)Wyatt Couch >115%SM662:02.169 A-Q22:02.1692:02.169 A-Q22:03.291 A-R22:03.392 A-R2+0.844 A-R2122.5 A-R233.243 A-Q235.205 A-Q253.822 A-Q2
34Mazda Miata (1999)Max Logemann >115%SM32:02.199 B-Q2sector data unreliable2:02.199 B-Q22:02.274 B-R12:03.047 B-R1+1.052 B-R1127.6 B-P26.21829.11843.340
35Mazda Miata (2003)Brett Revetta >115%SM482:02.373 B-Q12:02.2072:02.373 B-Q12:02.639 B-R22:03.104 B-R1+0.791 B-R1102.0 B-Q132.995 B-Q235.057 B-Q154.155 B-Q1
36Mazda Miata (1993)Alex Pollard >115%SM472:02.418 B-P2:02.4182:03.389 B-Q22:03.247 B-R22:04.086 B-R2+1.144 B-R2122.9 A-R133.102 B-R235.272 B-R154.482 B-Q2
37Mazda Miata (1999)Todd Launchbaugh >115%SM13, 732:02.731 B-Q22:02.4862:02.731 B-Q22:02.838 B-R12:03.815 B-R2+0.739 B-R2100.8 B-R133.200 B-R235.125 B-R254.161 B-R1
38Mazda Miata (2003)Jeremy Rutter >115%SM372:03.024 A-Q22:02.7022:03.024 A-Q22:04.170 A-R22:04.257 A-R2+0.496 A-R2122.6 A-Q133.350 A-Q135.216 A-Q154.136 A-Q2
39Mazda Miata (1999)David Mitchell >115%SM752:03.396 A-P2:03.3962:08.722 A-Q22:10.195 A-R22:11.410 A-R2+1.502 A-R2124.6 A-Q234.572 A-Q136.800 A-Q153.851 A-P
40Mazda Miata (2003)Jake Johnson >115%SM1512:03.918 A-Q22:03.6242:03.918 A-Q22:04.562 A-R22:05.101 A-R2+1.367 A-R2126.2 A-R133.473 A-Q235.575 A-Q254.576 A-Q2
41Mazda Miata (1993)Sam Rezai >115%SM1772:03.923 A-Q12:03.9102:03.923 A-Q12:05.864 A-R12:06.551 A-R1+1.027 A-R1127.3 A-Q133.474 A-Q135.897 A-Q154.539 A-Q1
42Mazda Miata (1999)Cooper Hicks >115%SM862:05.080 A-R12:04.7762:05.276 A-Q22:05.080 A-R12:05.643 A-R1+1.082 A-R1121.0 A-R133.780 A-R135.806 A-Q155.190 A-Q2
43Mazda Miata (1991)Hendrik Webster >115%SM972:05.607 A-Q22:04.6972:05.607 A-Q22:05.928 A-R22:06.497 A-R2+0.937 A-R2125.2 A-Q133.857 A-Q235.824 A-Q255.016 A-Q1
44Mazda Miata (2000)Nicholas Stewart >115%SM872:06.288 A-Q22:06.0282:06.288 A-Q22:07.124 A-R22:08.162 A-R2+1.541 A-R2123.1 A-P34.202 A-Q236.128 A-Q255.698 A-Q1
45Mazda Miata (1990)Sayo Haraishi >115%SM342:07.037 B-Q12:06.5012:07.037 B-Q12:08.275 B-R12:08.790 B-R1+1.938 B-R1100.2 B-Q134.243 B-Q136.262 B-Q155.996 B-Q1
46Mazda Miata 0Preston Lewis >115%SM118, 102:07.663 A-R22:07.2012:08.505 A-Q22:07.663 A-R22:08.201 A-R2+1.310 A-R2125.2 A-R234.455 A-R236.398 A-R256.348 A-R2
47Mazda Miata (2001)William Sturgeon >115%SM1182:08.519 A-Q12:08.1782:08.519 A-Q12:11.184 A-R22:11.810 A-R2+1.057 A-R2118.9 A-Q134.873 A-Q136.458 A-Q156.847 A-Q1
48Mazda MiataBill Nelson >115%SM1992:10.339 B-Q12:09.5822:10.339 B-Q12:11.321 B-R12:12.199 B-R1+2.275 B-R194.8 B-R235.256 B-R137.267 B-Q157.059 B-Q1
49Mazda Miata (1990)John Rice >115%SM202:11.974 A-Q22:11.6252:11.974 A-Q22:13.511 A-R12:14.141 A-R1+1.656 A-R1115.3 A-R235.615 A-Q237.635 A-Q258.375 A-Q2
50Mazda Miata (1990)Lauren Lewis >115%SM452:12.076 A-Q12:11.6882:12.076 A-Q12:12.821 A-R12:14.152 A-R1+2.986 A-R1112.2 A-R235.483 A-R137.835 A-Q158.370 A-Q1

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
Elan DP02/MazdaP11:32.576Jim Devenport1:32.872Jim Devenport1:33.972Jim Devenport171.9Jim Devenport25.461Jim Devenport26.606Jim Devenport40.217Jim Devenport
Dauntless StohrP21:36.516Johnnie Crean1:36.516Johnnie Crean1:37.287John Manfroy160.4John Manfroy25.956Johnnie Crean27.257John Manfroy42.386John Manfroy
Stohr WF1P11:38.716Kevin Mitz1:38.716Kevin Mitz1:39.638Kevin Mitz155.4Kevin Mitz26.934Kevin Mitz28.397Kevin Mitz43.336Kevin Mitz
Penton Norma M20FCP11:39.296Joseph Moran1:39.296Joseph Moran1:40.832Joseph Moran149.0Joseph Moran27.106Joseph Moran28.111Joseph Moran43.651Joseph Moran
Mazda MiataSM/STU311:41.720John Stott2:00.831William Wallis2:01.538Whitfield Gregg153.3John Stott26.218Max Logemann29.118Max Logemann43.340Max Logemann
Mazda RX-3STU11:50.913Tony Rivera1:50.913Tony Rivera1:52.737Tony Rivera135.2Tony Rivera30.415Tony Rivera32.456Tony Rivera47.999Tony Rivera
BMW M3STU11:52.380Wilson Powell1:55.401Wilson Powell1:53.843Wilson Powell102.6Wilson Powell30.577Wilson Powell32.372Wilson Powell49.215Wilson Powell
Honda S2000STU11:53.640Rylan Hazelton1:55.834Rylan Hazelton1:53.640Rylan Hazelton134.8Rylan Hazelton30.582Rylan Hazelton32.779Rylan Hazelton49.779Rylan Hazelton
Ford MustangAS51:55.849Roger Eagleton1:56.445Roger Eagleton1:55.849Roger Eagleton135.2Ross Murray31.659Roger Eagleton33.571Roger Eagleton50.288Ross Murray
BMW 330STU11:56.492Sean Lovett1:56.492Sean Lovett1:57.049Sean Lovett133.7Sean Lovett31.816Sean Lovett33.669Sean Lovett50.941Sean Lovett
Nissan 300ZXSTU11:59.183James Slechta1:59.183James Slechta2:00.458James Slechta132.0James Slechta32.882James Slechta34.528James Slechta51.773James Slechta
Mazda MX-5STU21:59.707Oscar Jackson2:04.115Dale Shoemaker1:59.707Oscar Jackson125.9Dale Shoemaker32.339Oscar Jackson34.219Oscar Jackson52.330Oscar Jackson
Mazda RX-7STU12:00.248Michael Lewis2:00.248Michael Lewis130.4Michael Lewis32.729Michael Lewis34.570Michael Lewis52.880Michael Lewis
Mazda MiattaSM12:01.816William Rasmussen2:01.816William Rasmussen2:02.486William Rasmussen125.6William Rasmussen33.179William Rasmussen34.870William Rasmussen53.902William Rasmussen

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

STU E&O STU NA Weight Chart.

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

Summary

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

As printed in Fastrack

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

STU Alternate OEM Miata Intake Manifold

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

Summary

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

As printed in Fastrack

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

STU 2022 Toyota GR Cup for STU

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

Summary

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

As printed in Fastrack

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

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

AS Crate Motor Part Numbers

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

Summary

wordingAS crate motor part number specified: GM Performance CT400 P/N 19370604 engine assembly for GM vehicles.

As printed in Fastrack

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

AS Request wheel size change

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

Summary

fasterAS Spec Lines Ford Mustang GT 5.0L (15-17) max wheel size increases to 19.0 inches.

As printed in Fastrack

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

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

AS Alternative Upper Front Control Arms for Dodge Challenger

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

Summary

wordingAS Dodge Challenger 5.7L/6.1L/6.4L V8 now permits SPC-66045 alternate front upper control arms.

As printed in Fastrack

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

AS Front Brake Caliper Adapters for Dodge Challenger

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

Summary

wordingAS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front brake caliper adapters for updated or backdated components.

As printed in Fastrack

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

STU ST Electric-Assisted Steering Systems

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

Summary

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

As printed in Fastrack

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

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

AS Request to Classify 1970-1981 Camaro and Firebird in AS

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

Summary

cars addedChevrolet Camaro, Pontiac Firebird 70-81 Full Prep classified AS at 3400-3600 lbs with 250 lb weight reduction.

As printed in Fastrack

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

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

AS Fuel Cell 12

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

Summary

wordingAS class: multiple cars gain fuel cell placement note allowing 24 inches from standard tank, unrestricted filler location.

As printed in Fastrack

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

Show 22 more lines

installation of a safety fuel cell.”
Chevrolet Camaro SS (V8) (10-15): “Fuel cells must be located within 24 inches of the standard tank. The 24 inch
measurement is taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with
installation of a safety fuel cell.”
Chevrolet Camaro (10-15): “Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is
taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a
safety fuel cell.”
Dodge Challenger (08-20): “Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is
taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a
safety fuel cell.”
Ford Mustang GT (05-14): “Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is
taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a
safety fuel cell.”
Ford Mustang Coupe GT (05-14): “Fuel cells must be located within 24 inches of the standard tank. The 24 inch
measurement is taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with
installation of a safety fuel cell.”
Ford Mustang GT 5.0l (15-17): “Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement
is taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a
safety fuel cell.”
Ford Mustang GT (05-14): “Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is
taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a
safety fuel cell.”

AS Please Classify the 6th Gen Into AS.

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

Summary

cars addedChevrolet Camaro 16- Full Prep classified into AS at 3400 lbs with 250 lb weight reduction.

As printed in Fastrack

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

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Chevrolet
Camaro (16-)
Full Prep
110.6 3.42, 2.28,

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

STU Letter #35397 addendum

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

Summary

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

As printed in Fastrack

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

STU S54 Drysump

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

Summary

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

As printed in Fastrack

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

AS spec lines

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

Summary

cars addedAS adds Ford Mustang GT 05-14 Restricted prep Engine with 62mm FPR, 3400 lbs minimum, 18-inch wheels.

As printed in Fastrack

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

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

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

AS Restricted Prep Aftermarket Parts Request

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

Summary

wordingAS Camaro/Firebird and GTO LS1 connecting rods approved: Callies CSC6100DS6A2AH, Scat 2-1CR6100-944, GM 12649190.

As printed in Fastrack

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

AS Allowance of 11

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

Summary

fasterAS Cadillac CTS-V, Chevrolet Camaro SS, Dodge Challenger, Ford Mustang GT, Pontiac GTO allowed 11" wheels until 3/1/25.

As printed in Fastrack

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

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In AS Spec Lines, Pontiac GTO (04-06), add to Notes the following:
"11" wide wheels can be used until 3/1/25."

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

AS 6th gen Camaro limited prep

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

Summary

cars addedAS Chevrolet Camaro 1LE (2016-) classified with 3600 lbs minimum weight, 60mm restrictor, 275 tires.

As printed in Fastrack

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

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(2016-)
110.6 2.66,1.78,1.30,0.74,.5 (F)

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

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

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

Summary

cars addedAS Chevrolet/Pontiac Camaro & Firebird 82-92 5.7L LS1 classified at 3200 lbs with 65mm restrictor plate required.

As printed in Fastrack

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

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

AS Full Prep Head

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

Summary

otherAS Chevrolet Camaro, Firebird, and Ford Mustang models permitted to use Flo Tek cylinder heads.

As printed in Fastrack

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

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In AS Spec Lines, Ford Mustang Including Cobra 94-04, add to Notes the following:
"Flo Tek Part # 203-500 are permitted."
In AS Spec Lines, Ford Mustang GT (05-14), add to Notes the following:
"Flo Tek Part # 203-500 are permitted."

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

AS Request for Classification of 2018-2023 mustang In

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

Summary

cars addedAS Ford Mustang GT 5.0L (2018-) classified at 3600 lbs with 60mm restrictor, Brembo BBK permitted.

As printed in Fastrack

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

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

STU RWD Turbo Disadvantage

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

Summary

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

As printed in Fastrack

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

SM 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."

SM 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

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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

SM 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:

SM 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."

AS Mustang transmission ratios

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

Summary

unclearAS Ford Mustang GT models gain alternate transmission ratio options for 2024-09-01.

As printed in Fastrack

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

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

STU R53 15% Pulley Request

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

Summary

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

As printed in Fastrack

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

SM 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."

STU Request to Remove Miata Hubs from General category

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

Summary

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

As printed in Fastrack

In GCR, Section 9.1.4.M.18., change as follows:
"18. Allow alternate front wheel front hubs, Mazda Motorsports Development Part #0000-04-5HUB-S1, for the 90-05 Mazda
Miata: Mazda Motorsports Development Part #0000-04-5HUB-S1."

STU BMW N54/N55 Engine Allowance

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

Summary

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

As printed in Fastrack

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

AS Increase Coyote Engine Restrictor to 80mm

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

Summary

fasterAS Ford Mustang Coyote engines increase restrictor to 80mm from 64mm or 67mm.

As printed in Fastrack

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

STU Audi 1.8t Wagon STU Table B

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

Summary

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

As printed in Fastrack

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

AS Performance Pack for 2015+ Mustang

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

Summary

fasterAS Mustang GT 05-14 4.6L loses 300 lbs; 15-17 and 2018+ models lose 61mm and 60mm restrictors respectively.

As printed in Fastrack

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

Show 10 more lines

Ratios 3.66, 2.43, 1.69, 1.32, 1.00, .68."
In AS Spec Lines, Ford Mustang GT 5.0l (15-17) Restricted Preparation, change Notes as follows:
"Max. Wheel Size: Dia. 18.0 inches. Stock brakes or alternate Ford Brembo Brake caliper (Ford Racing Kit #M-2300-S) may be
used. 61mm flat plate restrictor required. Fuel cells must be located within 24 inches of the standard tank. The 24 inch
measurement is taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with installation
of a safety fuel cell. 11” wide wheels can be used until 3/1/25. Performance pack front and rear spoiler, body kit allowed."
In AS Spec Lines, Ford Mustang GT 5.0L (2018-), change Notes as follows:
"Package Brembo front BBK and 380mm rotors permitted (Ford PN M-2300-V) at no weight penalty. 60mm flat plate restrictor
required. 2014 Mustang GT exhaust manifolds permitted. Ford Racing oil pan #M-6675-M50BR permitted. Alternate
transmission Ratios 3.24, 2.10, 1.42, 1.00, 0.81, .062. Performance pack front and rear spoiler, body kit allowed."

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

AS Gear Ratios

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

Summary

wordingAS class gear ratio options specified for multiple American muscle cars, including Cadillac CTS-V, Chevrolet Camaro, Ford Mustang, Dodge Challenger, and Pontiac GTO.

As printed in Fastrack

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

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"3.42, 2.28, 1.45, 1.00 or 2.95, 1.94, 1.34, 1.00, 0.73 or 3.35, 1.93, 1.29, 1.00, 0.61 or 2.20, 1.64,1.28,1.00 or 2.88, 1.91, 1.33,
1.00"
Chevrolet/Pontiac Camaro & Firebird (93-02) Full Prep:
"3.42, 2.28, 1.45,1.00 or 2.95, 1.94,1.34, 1.00,0.73or 3.35, 1.93,1.29, 1.00,0. 61 or 2.88, 1.91, 1.33, 1.00 or 3.27, 1.98, 1.34, 1.00,
0.68 or 2.20,1.64,1.28,1.00 or 2.87,1.89,1.28,1.00,.81"
Chevrolet/Pontiac Camaro & Firebird (93-02) Restricted prep:
"2.97, 2.07, 1.43, 1.00, 0.80, 0.62 or 3.36, 2.07, 1.35, 1.00, .80, .62 or 2.66, 1.78, 1.30, 1.00, 0.74, 0.50 or 2.88, 1.91, 1.33, 1.00 or
2.20, 1.64,1.28,1.00"
Chevrolet Camaro SS (V8) (10-15) Restricted Prep:
"3.01, 2.07, 1.43, 1.0, .84, .57 or 2.88, 1.91, 1.33, 1.00 or 2.20, 1.64,1.28,1.00"
Chevrolet Camaro (10-15) Full Prep:
"3.42, 2.28, 1.45,1.00 or 2.95, 1.94,1.34, 1.00, 0.73or 3.35, 1.93,1.29, 1.00,0. 61 or 2.88, 1.91, 1.33, 1.00 or 3.27, 1.98, 1.34, 1.00,
0.68 or 2.20, 1.64,1.28,1.00 or 2.87,1.89,1.28,1.00,.81"
Chevrolet Camaro (16-) Full Prep:
"3.42, 2.28, 1.45,1.00 or 2.95, 1.94,1.34, 1.00, 0.73or 3.35, 1.93,1.29, 1.00,0. 61 or 2.88, 1.91, 1.33, 1.00 or 3.27, 1.98, 1.34, 1.00,
0.68 or 2.20, 1.64,1.28,1.00 or 2.87,1.89,1.28,1.00,.81"
Chevrolet Camaro, 1LE (16-):
"2.66,1.78,1.30, 0.74,.50 or 2.88, 1.91, 1.33, 1.00 or 2.20, 1.64,1.28,1.00 or 2.88, 1.91, 1.33, 1.00 or 2.20, 1.64,1.28,1.00"
Dodge Challenger (08-20) Restricted Preparation 5.7L, 6.1L, or 6.4L V8 (Iron block, Aluminum heads), 2 valves/cylinder:
"2.97, 2.1, 1.46, 1.00, 0.74, 0.50 or 2.26, 1.58, 1.19, 1.00, 0.77, 0.63 or 2.88, 1.91, 1.33, 1.00 or 2.20, 1.64,1.28,1.00"
Ford Mustang Incl. Cobra & Cobra R (79-93) and Mercury Capri (79-86) Full Prep:
"3.07, 1.72, 1.00, 0.70 or 2.95, 1.94, 1.34, 1.00, 0.63 or 3.35, 1.99, 1.33, 1.00, 0.68 or 2.87 1.89 1.28 1.00 0.81"
Ford Mustang Incl. Cobra & Cobra R (79-93) and Mercury Capri (79-86) with Restricted Prep Engine:
"2.95, 1.94, 1.34,1.00, 0.63 or 3.35,1.99,1.33, 1.00, 0.69 or 2.88, 1.91, 1.33, 1.00 or 3.27,1.98, 1.34, 1.00, 0.68, 3.66, 2.43, 1.69,
1.32, 1.00, .68. or 2.87,1.89,1.28,1.00,.81"
Ford Mustang Including Cobra 94-04 Full Prep:
"3.07, 1.72, 1.00, 0.70 or 2.95, 1.94, 1.34, 1.00, 0.63 or 3.35, 1.99, 1.33, 1.00, 0.68 or 2.88, 1.91, 1.33, 1.00 or 3.27, 1.98, 1.34,
1.00, 0.68 or 2.88, 1.91, 1.33, 1.00 or 3.27, 1.98, 1.34, 1.00, 0.68 or 2.20, 1.64,1.28,1.00 or 2.87 1.89 1.28 1.00 0.81"
Ford Mustang Cobra and GT 94-95 (Restricted Prep):
"3.35, 1.99, 1.33, 1.00, 0.68 or 2.88, 1.91, 1.33, 1.00 or 2.20, 1.64,1.28,1.00"
Ford Mustang including Cobra 96-04 (Restricted Prep) 4.6L two and four valve motor:
"3.35, 1.99, 1.33, 1.00, 0.68 or 3.27, 1.98, 1.34, 1.00, 0.67 or 3.37, 1.99, 1.33, 1.00, 0.68 or 3.38, 2.00, 1.32, 1.00, 0.68 or 2.88,
1.91, 1.33, 1.00 or 2.20, 1.64,1.28,1.00"
Ford Mustang GT (05-14) Full Prep:
"3.38, 2.00, 1.32, 1.00, 0.68 or 3.66, 2.43, 1.69,1.32, 1.00, 0.65 or 2.88, 1.91, 1.33, 1.00 or 2.20, 1.64,1.28,1.00"
Ford Mustang GT 5.0l (15-17) Restricted Preparation:
"3.66, 2.43, 1.69,1.32, 1.00, .65 or 4.69, 2.98,2.14, 1.76,1.52, 1.27,1.00, 0.85, 0.68, 0.63, or 3.24, 2.10, 1.42, 1.00, 0.81, .062. or
2.88, 1.91, 1.33, 1.00 or 2.20, 1.64,1.28,1.00"
Ford Mustang GT 5.0L (2018-) Restricted Preparation:
"2.97, 2.07, 1.43, 1.00, 0.84, 0.57 or 2.88, 1.91, 1.33, 1.00 or 2.20, 1.64,1.28,1.00"
Pontiac GTO (04-06) Restricted Prep.
"2.97, 2.07, 1.43, 1.00, 0.84, 0.57 or 2.88, 1.91, 1.33, 1.00 or 2.20, 1.64,1.28,1.00"

AS ECU specs for LS engine

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

Summary

fasterAS LS-engine cars gain ECU freedom; Camaro/Firebird 93-02 LS1 removes fuel cell location restriction.

As printed in Fastrack

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

Show 14 more lines

"Any ECM may be used."
In AS SPEC LINES, Chevrolet/Pontiac Camaro & Firebird (93-02) Restricted Prep.5.7L V-8 LT1, add to Notes as follows:
"Any ECM may be used."
In AS SPEC LINES, Chevrolet/Pontiac Camaro & Firebird (93-02) Restricted Prep. 5.7L V-8 LT1; 98-02 , change Notes as follows:
"5.7L LS1:
GM Performance Parts camshaft Kit P/N-19355738 is permitted. Cylinder Bore, 99 mm; Stroke, 92 mm; Intake Valve Diameter,
50.8; Exhaust Valve Diameter, 39.4 mm; Throttle Body Bore, 75 mm; SLP Intake Lid (SLP part number 21044 (98-99) and 21045
(00-02)) is permitted.
Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is taken from the perimeter of the
stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a safety fuel cell.
1-3/4 headers allowed. For the LS1connecting rods Callies P/NCSC6100DS6A2AH, Scat rods P/N2-1CR6100-944, GM performance
rods P/N12649190. Any ECM may be used."
In AS SPEC LINES, Chevrolet Camaro SS (V8) (10-15) Restricted Prep., add to Notes as follows:
"Any ECM may be used."

STU Merger GT3 to STU

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

Summary

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

As printed in Fastrack

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

STU GT3 TCR Tire allowance

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

Summary

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

As printed in Fastrack

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

P Correct text in engine table notes

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

Summary

wordingPrototype Staudacher and unrestricted engine notes corrected for minimum weight wording.

As printed in Fastrack

In Prototype Engine Table, Spec Line B, change the notes as follows:
"Staudacher cars may run 950 lb min. wt. minimum weight with 38.5mm flat plate intake restrictor."
In Prototype Engine Table, Spec Line D, change the notes as follows:
"No restrictor required at 1150 lb min. wt. minimum weight."

P Update Prototype class designation

#37653 from Club Racing Board · Rule change · TB 25-02 (2025-02 Fastrack)

Summary

wordingPrototype class renamed from P1 to P, affecting designation throughout rules with no performance changes.

As printed in Fastrack

In Categories and Classes, GCR section 9.1, change as follows:
"9.1.8. SPORTS RACING CATEGORY CLASSES
A Sports Racing (ASR) Regional Class
Prototype 1 (P1)"
In Homologation Requirements, GCR section 9.2.2, change as follows:
"All Formula, Sports Racing, and P1, and P2 cars must be constructed in strict accordance with the rules and regulations
contained in the current GCR unless specifically excepted."
In Non-Metallic Wheel/Chassis Construction, GCR section 9.3.37, change as follows:

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"Non-metallic wheel construction is prohibited. Non-metallic chassis construction is prohibited, except in ASR, P1, FS and FA."
In Appendix B, GCR section 1.4.2.G, change as follows:
"It is preferable not to combine GT1, AS, T1, T2, T3, and STU with P1, P2, SRF, FP, HP, or GTL."
In Appendix C, GCR section 2.6.G, change as follows:
"A 14 or 15 year-old must complete his first SCCA driver school in a car not classed in GT1, GT2, FA, FB, F S, ITR, ASR, P1, P2, or
T1."
In Appendix E, section 1, change as follows:
"Depending on the length and banking of the oval course being used, it is recommended that Regions consider restricting the
faster classes (GT1, FA, and P 1) from competition at oval track events."
In Sports Racing Category, GCR section 9.1.8.1, change as follows:
"The SCCA Sports Racing Category shall be for automobiles which are designed and constructed for road racing competition,
offering provisions for a driver and passenger, or a driver alone (single-seater). They shall conform to the following
requirements. Sports Racers Cars except SRF & SRF3 homologated prior to 1-1-2014 are eligible to compete as P1 or P2 as long
as they meet applicable class rules,; no re-homologation is required."
"Single seat Formula car chassis (Ex.: FA, FC, FF, FV) fitted with enclosed bodies (as specified in these rules) may run in a Sports
Racing/Prototype Class (ASR, P 1, P2) provided they comply with the requirements of the Classification Specification and GCR
Section 9."
In Sports Racing Category, GCR section 9.1.8.2, change as follows:
"In an effort to control shock/damper technology and cost to a level reasonable for Road Racing, in ASR, P1, and P2, any fluid
dampers are allowed with the following restrictions:"

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

STU BMW N54/N55 Engine Allowance Follow Up

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

Summary

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

As printed in Fastrack

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

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

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

Summary

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

As printed in Fastrack

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

STU Question About a Weight Modifier

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

Summary

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

As printed in Fastrack

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

AS Race memo

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

Summary

unclearAS Spec Lines removes ECM flexibility restriction from five Cadillac and Chevrolet/Pontiac V8 models.

As printed in Fastrack

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

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"Any ECM maybe used."
Chevrolet Camaro SS (V8) (10-15) Restricted Prep. 6.2L V8 (Aluminum Block, Aluminum Heads), 2 valves per cylinder:
"Any ECM maybe used."

STU Increase Minimum Weight

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

Summary

slowerSTU GT3U minimum weight increases 150 to 250 pounds.

As printed in Fastrack

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

AS Flotek Head Plunge Cut Inconsistencies

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

Summary

unclearAS Flotek Head plunge cut dimensions figure updated in GCR Section 9.1.6.

As printed in Fastrack

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

AS Notes clean up

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

Summary

wordingAS class notes cleanup: multiple Camaro, Firebird, CTS-V, Challenger, Mustang specs and fuel cell/ECM/head restrictions removed.

As printed in Fastrack

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

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#s 608979, 608879."
Chevrolet Camaro, Pontiac Firebird (70-81) Restricted Prep.:
"Any ECM maybe used."
Chevrolet/Pontiac Camaro & Firebird (82-92) Full Prep.:
"Engine built to A/S Build Sheet specifications with the following: Head Casting #s: 14101081, 14014416 Port Volume (Max.): 081
cast¬ing: 170.00 cc IN/65.00 EX; 416 Casting 168.00cc IN/60.00 EX with a 250 lb weight reduction. Edelbrock Cylinder Head Part
#s 608979, 608879 are permitted. For regional competition only, unmodified GM Performance cylinder head part #s 19300955,
19300956 may be used with Allstar restrictor plate part# ALL26180 and 1.250 inserts part# ALL26186 installed between intake
manifold and insulator. Gaskets may be used (each gasket can be no thicker than .125 inches), one on each side of the restrictor.
All intake air must pass through the inserts of the restrictor plate. Alternate gear ratio sets 2.88, 1.91, 1.33, 1.00 or 3.27, 1.98,
1.34, 1.00, 0.68 are permitted. Flo Tek Head part #102-500 are permitted."
Chevrolet/Pontiac Camaro & Firebird (82-92) Restricted prep engine:
"Any ECM maybe used."
Chevrolet/Pontiac Camaro & Firebird (93-02) Full Prep:
"Engine built to A/S Build Sheet specifications with the following: Head Casting #’s: 14101081, 14014416; Port Volume (Max.):
081 casting: 170.00 cc IN/65.00 EX; 416 Casting 168.00cc IN/60.00 EX with a 250 lb weight reduction. Edelbrock Cylinder Head
Part #’s 608979, 608879 are permitted. For regional competition only, unmodified GM Performance cylinder head part #s
19300955, 19300956 may be used with Allstar restrictor plate part# ALL26180 and 1.250 inserts part# ALL26186 installed
between intake manifold and insulator. Gaskets may be used (each gasket can be no thicker than .125 inches), one on each side
of the restrictor. All intake air must pass through the inserts of the restrictor plate. Alternate gear ratio sets 2.88, 1.91, 1.33, 1.00
or 3.27, 1.98, 1.34, 1.00, 0.68 are permitted. Fuel cells must be located within 24 inches of the standard tank. The 24 inch
measurement is taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with
installation of a safety fuel cell. Flo Tek Head part #102-500 are permitted."
Chevrolet/Pontiac Camaro & Firebird (93-02) Restricted Prep:
"Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is taken from the perimeter of the
stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a safety fuel cell. Any ECM maybe used."
Chevrolet Camaro SS (V8) (10-15) Restricted Prep:
"Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is taken from the perimeter of the
stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a safety fuel cell. Any ECM maybe used."
Chevrolet Camaro (10-15) Full Prep:
"Engine built to A/S Build Sheet specifications with the following: Head Casting #’s: 14101081, 14014416; Port Volume (Max.):
081 casting: 170.00 cc IN/65.00 EX; 416 Casting 168.00cc IN/60.00 EX with a 200 lb weight reduction. Edelbrock Cylinder Head
Part #’s 608979, 608879 are permitted. Alternate gear ratio sets 2.88, 1.91, 1.33, 1.00 or 3.27, 1.98, 1.34, 1.00, 0.68 are
permitted. Fuel cells must be located within 24 inches of the standard tank. The 24-inch measurement is taken from the
perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a safety fuel cell. Flo Tek
Head part #102-500 are permitted. Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is
taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a safety fuel
cell."
Chevrolet Camaro (16-) Full Prep:
"Engine built to A/S Build Sheet specifications with the following: Head Casting #’s: 14101081, 14014416; Port Volume (Max.):
081 casting: 170.00 cc IN/65.00 EX; 416 Casting 168.00cc IN/60.00 EX with a 200 lb weight reduction. Edelbrock Cylinder Head
Part #’s 608979, 608879 are permitted, Flo Tek Head part #102-500 are permitted."
Chevrolet Camaro, 1LE (16-):
"60mm flat plate restrictor required. Any ECM maybe used."
Dodge Challenger (08-20) Restricted Preparation:
"80mm flat plate restrictor is required on the 6.4L engine. Fuel cells must be located within 24 inches of the standard tank. The
24 inch measurement is taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with
installation of a safety fuel cell."
Ford Mustang Incl. Cobra & Cobra R (79-93) and Mercury Capri (79-86) Full Prep:
"Engine built to A/S Build Sheet specifications with the following: Head Casting #s: F3ZE AA (GT40), F1ZE-AA (GT-40), F77E-AA
(GT- 40P), Port Volume (Max.): 143.00cc IN/54.00cc EX (GT-40 & GT-40P) with a 250 lb weight reduction. Edelbrock Cylinder
Head Part #s 602579, 602479 are permitted. For regional competition only, unmodified Ford Performance cylinder head part #s
M-6049-Z304DA7, M-6049-Z304D may be used with Allstar restrictor plate part# ALL26180 and 1.250 inserts part# ALL26186
installed between intake manifold and insulator. Gaskets may be used (each gasket can be no thicker than .125 inches), one on
each side of the restrictor. All intake air must pass through the inserts of the restrictor plate. Alternate gear ratio sets 2.88, 1.91,
1.33, 1.00 or 3.27, 1.98, 1.34, 1.00, 0.68 are permitted. Flo Tek Part # 203-500 are permitted."
Ford Mustang Incl. Cobra & Cobra R (79-93) and Mercury Capri(79-86) with Restricted Prep Engine:
"62mm flat plate restrictor is required. Fuel cells must be located within 24 inches of the standard tank. The 24 inch
measurement is taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with
installation of a safety fuel cell. MMR Secondary Timing Chain Tensioner Bracket #467893 is permitted."
Ford Mustang Including Cobra 94-04 Full Prep:
"Engine built to A/S Build Sheet specifications with the following: Head Casting #s: F3ZE AA (GT40), F1ZE-AA (GT-40), F77E-AA
(GT- 40P), Port Volume (Max.): 143.00cc IN/54.00cc EX (GT-40 & GT-40P) with a 250 lb weight reduction. Edelbrock Cylinder
Head Part #s 602579, 602479 are permitted. For regional competition only, unmodified Ford Performance cylinder head part #s
M-6049-Z304DA7, M-6049-Z304D may be used with Allstar restrictor plate part# ALL26180 and 1.250 inserts part# ALL26186
installed between intake manifold and insulator. Gaskets may be used (each gasket can be no thicker than .125 inches), one on
each side of the restrictor. All intake air must pass through the inserts of the restrictor plate. Alternate gear ratio sets 2.88, 1.91,
1.33, 1.00 or 3.27, 1.98, 1.34, 1.00, 0.68 are permitted. Flo Tek Part # 203-500 are permitted."
Ford Mustang GT (94-04) with Restricted Prep Engine:
"MMR Secondary Timing Chain Tensioner Bracket #467893 is permitted."
Ford Mustang Cobra and GT 94-95(Restricted Prep):
"1st Generation 5.0l Coyote 11-14 62mm FPR 2nd Generation 5.0l Coyote 15-17 61mm FPR Alternate transmission Ratios 3.66,
2.43, 1.69, 1.32, 1.00, .68. MMR Secondary Timing Chain Tensioner Bracket #467893 is permitted."
Ford Mustang including Cobra 96-04 (Restricted Prep):
"1st Generation 5.0l Coyote 11-14 62mm FPR 2nd Generation 5.0l Coyote 15-17 61mm FPR Alternate transmission Ratios 3.66,
2.43, 1.69, 1.32, 1.00, .68. MMR Secondary Timing Chain Tensioner Bracket #467893 is permitted."
Ford Mustang Coupe GT (05-14) Restricted Prep.:
"1st Generation 5.0l Coyote 11-14 62mm FPR 2nd Generation 5.0l Coyote 15-17 61mm FPR Alternate transmission Ratios 3.66,
2.43, 1.69, 1.32, 1.00, .68. MMR Secondary Timing Chain Tensioner Bracket #467893 is permitted. MT82 6 speed is permitted."
Ford Mustang GT (05-14) with Restricted Prep Engine:
"1st Generation 5.0l Coyote 11-14 62mm FPR 2nd Generation 5.0l Coyote 15-17 61mm FPR Alternate transmission Ratios 3.66,
2.43, 1.69, 1.32, 1.00, .68. MMR Secondary Timing Chain Tensioner Bracket #467893 is permitted. MT82 6 speed is permitted."
Ford Mustang GT 5.0l (15-17) Restricted Preparation:
"61mm flat plate restrictor required. Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement
is taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a safety
fuel cell. MMR Secondary Timing Chain Tensioner Bracket #467893 is permitted."
Ford Mustang GT 5.0L (2018-):
"60mm flat plate restrictor required. MMR Secondary Timing Chain Tensioner Bracket #467893 is permitted."

SM Clarify Tire Marking Regs

#38005 from Greg Amy · Rule change · TB 25-05 (2025-05 Fastrack)

Summary

wordingSM cars limited to one set of Hoosier SM 7.5 P205/50/ZR17 per Super Tour event weekend for dry sessions.

As printed in Fastrack

In GCR Section 9.1.7.C.1.6.c., change as follows:
"1. 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. SM cars are limited to one set of Hoosier SM 7.5 P205/50/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 SM competitors is required after the first dry qualifying or race (if rain in qualifying) session. It is
the competitor’sresponsibility to ensure their tires are marked prior to going on track for the next session. A mandatory impound

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for all SM 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 SM CCC, if assigned, for inspection. At the direction of the Hoosier Super Tour Series Tech Chief or SM CCC, the
competitor 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."

STU Wheel Size Inconsistency

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

Summary

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

As printed in Fastrack

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

AS Errors and Omission

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

Summary

slowerAS Ford Mustang GT 5.0L (15-17) flat plate restrictor reduced from 67mm to 64mm.

As printed in Fastrack

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

P Add missing punctuation marks

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

Summary

wordingClass P adds clarification notes on restrictor requirements, throttle bodies, Mazda 12A engine spec, and P2 auto-based engine rules.

As printed in Fastrack

In P Engine Table, Spec Line D notes, add the following:
"No restrictor required at 1150 lbs. minimum weight."
In P Engine Table, Spec Line G notes, add the following:
"Group CN non-composite chassis with Honda K20A-FD2 may use unrestricted individual throttle bodies at 1500 lbs. minimum
weight."
In P Table 1, Beasley B2 spec line notes, add the following:
"Engine must be Mazda 12A rotary with 40.5mm venturi. Car must comply with all other Prototype requirements."
In P Table 1, P2 cars built to 2000cc auto-based specification spec line notes, add the following:

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"Car must comply with all other P2 rules applicable to cars using stock production-based four-cylinder automotive engines.
Note: Competitors are also free to modify their cars to comply with the general Prototype rules and Engine Table Spec Line H
instead."

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

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

Summary

wordingAS LS1/LS6 5.3L truck engine gains four approved intake part numbers: 12561269, 88894095, 89017363, 89017364.

As printed in Fastrack

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

STU Table C: STU-GT3U Clarification

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

Summary

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

As printed in Fastrack

In STU Spec Line, Table C: STU-GT3U, change as follows:
Minimum Weight: “Current GT3 race weight plus 250 225 pounds”
Notes: "DOT approved tire with maximum section width of 245. GT3 cars base wheel is a maximum of 15”x9”. 18”x9” wheels
allowd with a 3% weight addition. GT3 cars utilizing 15”x7” wheels are limited to a maximum section width of 225 with a 25
pound weight reduction"
"All GT3U (Majors and Runoffs) cars using up to 15"x7" wheels limited to 225 section width tires shall run at current GT3 race
weight plus 225lbs. All Gt3U cars shall run a DOT approved tire with a maximum section width of 245. GT3U cars are allowed
optional 15"x9" wheels with a 1.5% weight addition or up to 18"x9" wheels with a 3.0% weight addition to the total weight

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including the 225 lbs."

AS Errors and Omissions

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

Summary

wordingAS Ford Mustang GT 05-14 Restricted Prep Engine gains alternative gear ratios: 3.66, 2.43, 1.69, 1.32, 1.00, .65

As printed in Fastrack

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

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

SM 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."

SM 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."

STU 2.8-3.2L N/A Engine Allowances

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

Summary

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

As printed in Fastrack

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

AS RE: Previous Letter 37695 Update

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

Summary

fasterAS Ford Mustang GT 5.0 2018- weight reduced from 3600 to 3525 lbs.

As printed in Fastrack

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

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

STU 2006-2015 Mazda Miata Intake Manifold

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

Summary

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

As printed in Fastrack

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

STU Requesting Approval of the JDM Honda h23a

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

Summary

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

As printed in Fastrack

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

STU STU-TCR Adjustments

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

Summary

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

As printed in Fastrack

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

STU Lotus Weight Reduction

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

Summary

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

As printed in Fastrack

In 9.1.2. GT2/ST Spec Lines, Lotus Evora GT4, change Weight as follows:
"2750 2700"
In STU Table B: Alternate Vehicle and Engine Allowances, change Weight as follows:
Lotus Elise Cup R: "2300 2250"
Lotus Elise SC/ Lotus Exige SC: "2300 2550
2500 2450"

P RM 25-05 - Prototype Engine Table A, 2 Cycle Restrictor Change

#38929 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)

Summary

slowerPrototype Engine Table A 2-cycle restrictor reduces from 40mm to 38mm venturi size.

As printed in Fastrack

Effective 8/1/25 in Prototype Engine Table, Spec Line A, change the restrictor as follows:
"40mm 38mm Restricted Venturi Size"

P 13B Rotary Engine Rules Change Request

#38856 from Jason Vinkemulder · Rule change · TB 25-09 (2025-09 Fastrack)

Summary

unclearP class 13B rotary engine restrictor changes to 40mm SIR fuel injection or 41.5mm venturi carburetor.

As printed in Fastrack

Effective 9/1/25 in Prototype Engine Table, Spec Line K, change the restrictor as follows:
"40mm SIR with fuel injection or 41.5mm venturi with carburetor"

P Add Radical Cup series Radical SR3 spec line to Table 1

#38916 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)

Summary

cars addedPrototype class adds Radical SR3 spec line to Table 1 effective 9/1/25.

As printed in Fastrack

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

STU Lotus Weight Reduction E&O

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

Summary

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

As printed in Fastrack

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

P Clarify spec line cars language

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

Summary

wordingPrototype P2 cars may now run P2 spec or modified Prototype spec in Prototype class; clarified language and added Radical Cup series table.

As printed in Fastrack

Effective 9/1/25, in Prototype, GCR section 9.1.8.B.K, change as follows:
"P2 cars may compete in either the Prototype class or the P2 class but must participate in the Prototype class to the extent
necessary to qualify for an invitation to the Runoffs in Prototype. P2 cars may be modified to comply with the general Prototype
rules and Prototype Engine Table or may continue to run in P2 specification in the Prototype class as permitted in Table 1 below."
Table 1 (Spec Line Cars)

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

AS Cadillac CTS-V BOP Weight Change

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

Summary

fasterAS Cadillac CTS-V 04-07 Restricted Prep weight reduced 50 lbs to 3400.

As printed in Fastrack

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

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

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

Summary

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

As printed in Fastrack

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

STU Turbo Inlet Restrictor Table

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

Summary

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

As printed in Fastrack

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

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

STU 275 Tire Rule

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

Summary

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

As printed in Fastrack

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

AS 1994 Mustang Spec Line Request

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

Summary

unclearAS Ford Mustang GT 94-04 Restricted Prep Engine now permits Ford Motorsport M-6250-F303 camshaft.

As printed in Fastrack

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

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

STU STU Honda Engine weight penalty

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

Summary

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

As printed in Fastrack

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

P Request to Continue to Allow Carbon Brakes

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

Summary

suspension & brakesPrototype carbon-carbon and carbon-ceramic brake rotors now permitted instead of prohibited.

As printed in Fastrack

In Prototype, GCR section 9.1.8.B.F.2, change as follows:
"Brake calipers may be ferrous or aluminum alloy. Effective 1/1/2026, carbon-carbon and carbon-ceramic brake rotors are
prohibited and rotors must be ferrous. Brake rotor material is unrestricted."

AS Restrictor Plate Change for Gen 2 Ford Coyote Engine

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

Summary

slowerAS Ford Mustang Restricted Prep engines lose 3 mm restrictor plate, from 64 mm to 61 mm.

As printed in Fastrack

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

STU Request for Permission on Aftermarket Turbo Kit and Intake

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

Summary

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

As printed in Fastrack

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

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Varies Chart Short blocks, heads, and intakes may be freely
swapped within these engine designations. May
use Jack Spania Racing 70 mm sheet-metal
aluminum Intake manifold. Must use stock
throttle body or Acura part number 16400-PND-
A17. Fab9 Tuning bottom-mount turbo kit
approved with one of the STU approved Turbos.

AS Edelbrock manifold (& timing kit) to Chevy LS Spec Lines Request

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

Summary

cars addedAS Chevy LS adds Edelbrock Performer RPM 71187 intake manifold with MSD 6014 ignition and 4776 Holly carburetor as spec line option.

As printed in Fastrack

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

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