BoP Lab / Buttonwillow Raceway Park

FP + GTX at Buttonwillow Raceway Park

No mapCal Club 2024

This track has been raced on 2 configurations (The Circuit, 2.57 mi; 2.92 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.

Pos	Car	Driver	Class	#	Lap	Theoretical	Qual	Race	5-lap stint	Consistency	Trap	S1	S2	S3
1	Chevrolet	Bob Blizzard	GTX	9	1:49.569 B-P	1:49.051					124.2 B-P	29.869 B-P	31.704 B-P	47.478 B-P
2	Ford Mustang GT4	Rob Scholl	GTX	22	1:49.596 B-R2	1:48.800		1:49.596 B-R2	1:50.003 B-R2	+0.917 B-R2	116.4 B-R2	30.070 B-R2	31.820 B-R1	46.910 B-R2
3	Porsche 981 Cayman	Moze Cowper	GTX	111	1:54.892 A-Q1	1:54.066	1:54.892 A-Q1	1:55.330 A-R2	1:55.654 A-R2	+0.622 A-R2	146.0 A-R1	31.377 A-R1	32.983 A-R2	49.706 A-Q1
4	Mazda RX-7	Michael Lewis	FP	32	1:55.440 B-R2	1:55.401	1:56.121 B-Q1	1:55.440 B-R2	1:56.358 B-R2	+2.235 B-R2	128.8 A-R2	31.255 B-R2	33.299 B-Q2	50.847 B-R2
5	Nissan Sentra SE-R	Brian Linn	FP	123, 3	1:55.722 B-R2	1:55.294	1:57.239 B-Q1	1:55.722 B-R2	1:56.460 B-R2	+1.971 B-R2	128.3 B-P	31.416 B-R2	33.400 B-R2	50.478 B-R2
6	Volkswagen GTI	Tim Linerud	FP	95	1:56.016 B-P	1:56.016		2:06.156 B-R1	2:07.807 B-R1	+3.270 B-R1	93.4 B-R2	33.738 B-R1	35.656 B-P	55.246 B-P
7	Mazda MIata	Steven Powers	FP	145	1:56.276 B-R2	1:55.982	1:57.032 B-Q1	1:56.276 B-R2	1:56.620 B-R2	+0.759 B-R2	134.3 A-Q2, A-R2	31.570 B-R2	33.696 B-R2	50.716 B-R2
8	Fiat X/1 9	Daniel Snow	FP	1	1:59.128 B-R2	1:58.152	2:00.398 B-Q1	1:59.128 B-R2	1:59.511 B-R2	+0.364 B-R2	137.8 A-R2	31.878 B-R2	34.053 B-R2	52.221 A-R2
9	Chevrolet Camero	Michael Arnheiter	GTX	63	1:59.339 B-P	1:56.800					124.8 B-P	32.354 B-P	33.705 B-P	50.741 B-P
10	Porsche 914-4	Garey Raymond >115%	FP	29	2:15.932 B-R2	2:15.932	2:21.274 B-Q1	2:15.932 B-R2	2:17.314 B-R2	+3.922 B-R2	84.8 B-R1	37.237 B-R2	39.091 B-R2	59.604 B-R2

One row per driver and car (a driver who changed cars has a row for each). Each cell is that driver's best in that car across the selected events, with the session it was set in. Best 5-lap stint is the mean of the driver's quickest five consecutive race laps, and consistency is how far their median race lap sat behind their best in that race (small is a driver who does it every lap); both come from the race with the best stint. The fastest in each column is purple, and a car whose best lap is more than 115% of the fastest in its class is greyed (marked ">115%" beside the driver) and left out of the colour scale. Click a column to sort, a row to highlight it. Theoretical lap is the sum of the best sectors, whichever laps they came from, and never slower than the best lap (where a car's fastest laps were recorded without sector times, its best lap is used). The 115% mark is about the car's best lap only: a car whose best lap is within 115% of the fastest in its class is never marked. Greyed sectors with no theoretical lap mean the sector times on file do not add up to a believable lap. Letters refer to the events above; Q is qualifying, R a race.

Sectors

S1 SF → IM1 0.65 mi
S2 IM1 → IM2 0.75 mi
S3 IM2 → SF 1.17 mi
Spd In → Out 0.03 mi

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

Car	Class	Drivers	Lap	Qual	Race	Trap	S1	S2	S3
Chevrolet	GTX	2	1:49.569Bob Blizzard			124.8Michael Arnheiter	29.869Bob Blizzard	31.704Bob Blizzard	47.478Bob Blizzard
Chevrolet	GTX	1	1:49.569Bob Blizzard			124.2Bob Blizzard	29.869Bob Blizzard	31.704Bob Blizzard	47.478Bob Blizzard
Chevrolet Camero	GTX	1	1:59.339Michael Arnheiter			124.8Michael Arnheiter	32.354Michael Arnheiter	33.705Michael Arnheiter	50.741Michael Arnheiter
Ford Mustang GT4	GTX	1	1:49.596Rob Scholl		1:49.596Rob Scholl	116.4Rob Scholl	30.070Rob Scholl	31.820Rob Scholl	46.910Rob Scholl
Porsche 981 Cayman	GTX	1	1:54.892Moze Cowper	1:54.892Moze Cowper	1:55.330Moze Cowper	146.0Moze Cowper	31.377Moze Cowper	32.983Moze Cowper	49.706Moze Cowper
Mazda RX-7	FP	1	1:55.440Michael Lewis	1:56.121Michael Lewis	1:55.440Michael Lewis	128.8Michael Lewis	31.255Michael Lewis	33.299Michael Lewis	50.847Michael Lewis
Nissan Sentra SE-R	FP	1	1:55.722Brian Linn	1:57.239Brian Linn	1:55.722Brian Linn	128.3Brian Linn	31.416Brian Linn	33.400Brian Linn	50.478Brian Linn
Volkswagen GTI	FP	1	1:56.016Tim Linerud		2:06.156Tim Linerud	93.4Tim Linerud	33.738Tim Linerud	35.656Tim Linerud	55.246Tim Linerud
Mazda MIata	FP	1	1:56.276Steven Powers	1:57.032Steven Powers	1:56.276Steven Powers	134.3Steven Powers	31.570Steven Powers	33.696Steven Powers	50.716Steven Powers
Fiat X 1/9	FP	1	1:59.128Daniel Snow	2:00.398Daniel Snow	1:59.128Daniel Snow	137.8Daniel Snow	31.878Daniel Snow	34.053Daniel Snow	52.221Daniel Snow
Porsche 914-4	FP	1	2:15.932Garey Raymond	2:21.274Garey Raymond	2:15.932Garey Raymond	84.8Garey Raymond	37.237Garey Raymond	39.091Garey Raymond	59.604Garey Raymond

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

2024-03-01 FP GCR Correction - Redundant HP Spec Lines

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

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

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

2024-03-01 FP Update FP Protege (01-03) Model Info

#35715 from Production Committee · Rule change · TB 24-03 (2024-03 Fastrack)

neutralFP Mazda Protégé ES (01-03) model designation updated to include /5 variant.

In FP Spec Lines, Mazda Protégé ES (01-03) change vehicle as follows:
"Mazda Protégé ES/5 (01-03)"

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

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

slowerGT2-ST Acura NSX minimum weight raised to 3000 lbs, restrictor increased to 45mm TIR.

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

2024-05-01 FP Request to Replace CRX Plastic Panels

#35876 from Darryl Saylor · Rule change · TB 24-05 (2024-05 Fastrack)

neutralFP Honda CRX 84-87 can replace plastic front header, rocker skirt, door cap panels with stock-appearance replicas in alternate materials.

In FP spec line "Honda CRX / CRX Si (84-87)", add the following wording to the Notes section:
"The plastic OE front header/nose body panel, lower rocker side-skirt, and lower door cap panel can be replaced by a
replica, which may be constructed of an alternate material, provided its appearance remains stock."

2024-05-01 FP FP data and parity

#35896 from Production Committee · Rule change · TB 24-05 (2024-05 Fastrack)

slowerFP Acura Integra and Honda Civic models now require 55mm Flat Plate Intake Restrictor.

In the following FP spec lines, add the following wording to the Notes section:
Acura Integra (90-93)
Acura Integra LS (94-01)
Acura Integra GSR (92-93)
Honda Civic Del Sol VTEC (94-97)
Honda Civic Si (99-00)
"55mm Flat Plate Intake Restrictor is required."

2024-06-01 FP NIssan 300ZX Z31 to EP

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

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

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

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

2024-06-01 FP RX7 1993 and Up Request In EP Spec Lines, classify

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

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

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

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

2024-06-01 FP Clean-up Multiple EP RX-8 Spec Lines In EP

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

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

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

2024-08-01 FP Errant entry in HP production line item

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

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

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

2024-10-01 FP Errors/emissions Honda Civic/CRX

#36700 from Martin Burk · Rule change · TB 24-10 (2024-10 Fastrack)

fasterFP Honda CRX/CRX Si 84-87 block material changes from Iron to Alum.

In FP Spec Lines, Honda CRX / CRX Si (84-87), change Block Mat'l as follows:
"~~Iron~~ Alum"

2024-11-01 FP 1275 HP Spridget Level 2 Only

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

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

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

2025-01-01 FP Request to Reduce Weight of BMW 325i/is E30 (84-91) Spec Line

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

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

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

2025-01-01 GTX Correct language regarding OEM Areo Devices

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

neutralTA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof requirement.

In GCR, Section APPENDIX L. 2013 TA2 TECHNICAL REGULATIONS, B.2.c., change as follows:
"B. Aerodynamic Devices
2. Rear wing
c. The entire rear wing assembly, including the end plates and any Gurney flap, shall be mounted level
with, or below, the peak of the roof. OEM aerodynamic devices do not need to adhere to the height rule."

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

2025-01-01 FP Fix Error in Spridget Spec Line

#37437 from Jason Stine · Rule change · TB 25-01 (2025-01 Fastrack)

neutralFP Spridget and Midget 1275cc and 1500cc spec line corrections to bore, stroke, displacement, and valve sizes.

In FP SPEC LINES, Austin-Healey Sprite Mk. I, II,III, IV MG Midget Mk I,II, III, IV & 1500, change the following:
1275cc:
Bore x Stroke: "~~68.1x78.4 (2.68x3.09)~~ 70.6x81.3 (2.78x3.20)"
Displacement: "~~(77.78)~~ 1275"
Valves IN & EX: ~~"(I) 32.1/(1.26) (E) 28.4/(1.12)~~ (I) 33.3/(1.31) (E) 29.5/(1.16)"
1500cc:
Bore x Stroke: "~~1.1x84.3~~ 73.7x87.4 (2.90x3.44)"
Displacement: "~~1491 (90.95)~~ 1493"

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Valves IN & EX: "(I) 36.6/(1.44) (E) ~~28.7~~ 29.7/(1.17)"

2025-01-01 FP Create ruleset that allows GTL cars to run in FP

#37485 from Club Racing Board · Rule change · TB 25-01 (2025-01 Fastrack)

neutralF Production now allows GT-Lite cars meeting Appendix N specifications to compete, effective 2025-01-01.

“~~(Effective January 1, 2026)~~ (Effective January 1, 2025)." Any GT-Lite (GTL) car meeting all of the requirements of Appendix N
GT-LITE CATEGORY SPECIFICATIONS for inclusion into F PRODUCTION" may compete in the F-Production class. For GTL cars
competing in FP, the level of preparation and modifications will be determined by Appendix N and not by PCS 9.1.5.”

2025-02-21 FP Effective date for Jan 2025 GCR updates

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

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

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

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

2025-03-01 FP Request Competition Adjustment to BMW Z3 2.5L

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

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

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

2025-03-01 FP Interpretation of Production Rules on Mirrors

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

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

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

2025-03-01 FP FP Class Adjustments

#37458 from Production Committee · Rule change · TB 25-01 (2025-01 Fastrack)

slowerFP Acura Integra and Honda Civic models get smaller 51mm intake restrictors, down from 55mm; Del Sol VTEC weight increases to 2290–2405 lbs.

In FP SPEC LINES, change Notes as follows:
Acura Integra (90-93): "(Effective 3/1/2025) ~~55mm~~ 51mm Flat Plate Intake Restrictor is required."
Acura Integra LS (94-01): "(Effective 3/1/2025) ~~55mm~~ 51mm Flat Plate Intake Restrictor is required."
Acura Integra GSR (92-93): "(Effective 3/1/2025) ~~55mm~~ 51mm Flat Plate Intake Restrictor is required."
Honda Civic Si (99-00): "(Effective 3/1/2025) ~~55mm~~ 51mm Flat Plate Intake Restrictor is required.
In FP SPEC LINES, change as follows:
Honda Civic Del Sol VTEC (94-97): "
Weight: "(Effective 3/1/2025) ~~2265 *2322 **2378~~ 2290 *2347 **2405

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Notes: "(Effective 3/1/2025) ~~55mm~~ 51mm Flat Plate Intake Restrictor is required."

2025-03-01 FP Weight Reduction for Honda S2000

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

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

In EP, Spec Lines make the following weight changes:

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

2025-03-01 FP Mazda 1999 Miata 1.8L

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

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

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

2025-03-01 FP Errors & Omissions

#37648 from Bryan Floyd · Rule change · TB 25-03 (2025-03 Fastrack)

neutralFP GTL Volkswagen Jetta Mark IV 4dr FWD 98.2 wheelbase newly classified.

In FP Spec Lines, Appendix N, GTL-FP Cars - Volkswagen, classify Jetta Mark - IV as follows:
GTL-FP Cars - VOLKSWAGEN
Model Years Body Style Drive-line Wheelbase (in) Notes
Jetta Mark - IV 4dr FWD 98.2

2025-03-01 FP GTL/FP consolidation 2025 Rules

#37659 from James Gregorius · Rule change · TB 25-03 (2025-03 Fastrack)

neutralFP Spec Lines option: carburettor chokes permitted as alternative to SIR, same size as listed SIR.

In FP Spec Lines, Appendix N: L.9, Fuel Injection System, add the following:
"As an option, induction system “Chokes” may be used where a SIR is required. Said chokes shall be fitted to each barrel of
carburetor/throttle body and all airflow into engine must pass through them. Choke size will be the same as listed SIR unless
noted."

2025-04-01 FP Request for Classification of Chevrolet Spark

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

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

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

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

2025-04-01 FP Request to Lower Ford Festiva Minimum Weight to 1600 LBS

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

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

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

2025-05-01 GTX Request to Classify Porsche GT2 RS Clubsport

#37972 from Paul Fairchild · Rule change · TB 25-05 (2025-05 Fastrack)

neutralGTX Porsche GT2 RS Clubsport classified with factory specifications required at all race events.

In GTX, Classify Porsche GT2 RS Clubsport, as follows:
GTX
Make Homologation Model Restrictor
(mm)
Weight
(lbs) Notes
Porsche GT2 RS Clubsport Must have factory specifications available at all race events

2025-06-01 GTX Ligier P3 LS Swap

#38164 from Bart Wolf · Rule change · TB 25-06 (2025-06 Fastrack)

unclearGTX Ligier LMP3 now allows any normally aspirated LS Chevrolet engine.

In GTX Spec Lines, GTX-MISC., Ligier, LMP3, 3.0L, Add to Notes the following:
"Allow any normally aspirated LS Chevrolet engine may be used."

2025-06-01 FP Base Weight Adjustment for H-Production X1/9 Spec Lines

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

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

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

2025-07-01 FP BMW Z4 update

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

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

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

2025-07-01 FP EP Fiat 124 Spider Competition Adjustment Request

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

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

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

2025-10-01 FP HP Plymouth Arrow spec omission

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

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

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

2025-10-01 FP Add Wheel Diameter to Appendix G

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

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

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

2025-10-01 FP Add TB ID tolerance to general Prod rules

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

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

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

2025-11-01 FP Please Lower Weight of 280Z

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

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

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

2025-11-01 FP Miata Weight Adjustment Follow Up

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

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

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

2025-11-01 FP Weight Break for 1098 Midget / Sprite

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

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

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

2025-11-01 FP HP Volvo 142 spec omission

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

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

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

2025-11-01 FP HP Mini DOHC 1.6

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

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

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

2025-11-01 FP 83-88 FP Scirocco Spec Line Creation

#38997 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)

neutralFP Scirocco 83-88 established as spec line with 1733–1803 lbs, 1715–1780 cc SOHC, 40/33 mm valves, Solex carbs or fuel injection.

In FP Spec Lines, classify Volkswagen Scirocco (83-88) as follows:

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

2025-11-01 FP Add to Rabbit description

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

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

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

2025-11-01 FP Clean-up 9.1.5.E.7e

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

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

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

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

2025-11-01 FP Add TB size to Ford Mustang (94-98) Spec Line

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

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

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

2025-11-01 FP Correct Existing VW Scirocco Spec Line

#39140 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)

fasterFP Volkswagen Scirocco: remove two engine variants (1715cc and 1780cc), lighten one variant to 1663 lbs, allow 15×7 wheels instead of 13×7.

In FP Spec Lines, Volkswagen Scirocco, change spec line as follows:

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

2025-12-01 FP TR2 Notes E&O

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

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

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

2025-12-01 FP Balance of Power

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

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

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

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

2025-12-01 FP Competition Adjustment Request

#39259 from David Strittmatter · Rule change · TB 25-12 (2025-12 Fastrack)

fasterFP Lancia Scorpion minimum weight drops 80 lbs, to 1950.

In FP Spec Lines, Lancia Scorpion, change Weight as follows:
"~~2030~~ 1950"

2025-12-01 FP Factory Roll Bar Removal on VW Convertible

#39268 from Tim Linerud · Rule change · TB 25-12 (2025-12 Fastrack)

neutralFP Volkswagen Rabbit Convertible no longer required to remove factory roll bar.

In FP Spec Line, Volkswagen Rabbit (Includes Convertible), remove the following wording in Notes:
"~~Factory roll bar must be removed on Cabriolet.~~"

2025-12-01 FP FP Parity Request

#39325 from Mason Workman · Rule change · TB 25-12 (2025-12 Fastrack)

slowerFP Acura Integras and Honda Civics gain 50–79 lbs; Mazda Miata and Mercury Capri compression ratio to 11.0:1, valve lift to .425".

In FP, change Weight as follows:
Acura Integra (90-93):
"~~2235~~ 2285
*~~2291~~ 2342
**~~2347~~ 2399"
Acura Integra LS (94-01):
"~~2260~~ 2310
*~~2317~~ 2368

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**~~2373~~ 2426"
Acura Integra GSR (92-93):
"~~2325~~ 2375
*~~2383~~ 2434
**~~2441~~ 2494"
Honda Civic Del Sol VTEC (94-97):
"~~2290~~ 2340
*~~2347~~ 2399
**~~2378~~ 2457"
Honda Civic Si (99-00):
"~~2250~~ 2300
*~~2306~~ 2358
**~~2363~~ 2415"
FP Spec Lines, change Notes as follows:
Mazda Miata 1.6L (90-97): "Comp. Ratio limited to ~~10.0:1~~ 11.0:1, Valve lift limited to ~~.390”~~ .425"."
Mercury Capri 1.6L (91-94): "Comp. Ratio limited to ~~10.0:1~~ 11.0:1, Valve lift limited to ~~.390”~~ .425"."

2025-12-01 FP Adjust former-GTL Honda's with B/D-Series Engines

#39374 from Production Committee · Rule change · TB 25-12 (2025-12 Fastrack)

slowerFP Honda B/D-series engines gain 105–120 lbs minimum weight across seven variants.

In GCR, Appendix N GTL inclusion into FP, Engines - HONDA, change Disp. (cc) – Weight (lbs) as follows:
"D15 – 1493cc – ~~1895~~ 2000
D15b7 – 1493cc – ~~1895~~ 2000
D16 – 1590cc – ~~1945~~ 2055
D16A – 1590cc – ~~1945~~ 2055
B16A – 1595cc – ~~1950~~ 2065
B18 – 1797cc – ~~2050~~ 2170
B18 – 1834cc – ~~2065~~ 2185"

2026-01-01 GTX Please Consider Adding a Spec Line to GTX Table 4 for the RCR T70

#39470 from Peter Jankovskis · Rule change · TB 26-01 (2026-01 Fastrack)

neutralGTX Misc Table 4 adds RCR T70 Coupe with 2200 lbs minimum weight, no restrictor specified.

In GTX-Misc. Table 4, classify RCR70 Coupe:
GTX – MISC. TABLE 4
Make Homologation Model Restrictor

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

2026-02-01 FP Request Toyota 5E Series Engines

#38208 from Scott Schick · Rule change · TB 26-02 (2026-02 Fastrack)

neutralFP class adds Toyota 5E DOHC 1497cc engine, 1900 lbs minimum weight, 23mm SIR induction.

In FP Appendix N, add spec line for the Toyota 5E engine to the "Engines - TOYOTA" section:

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

2026-02-01 FP Request for Toyota 4E Series Engines

#38209 from Scott Schick · Rule change · TB 26-02 (2026-02 Fastrack)

neutralFP Toyota 4E DOHC 1331cc engine added to Appendix N with 1900 lbs minimum weight.

In FP Appendix N, add spec line for the Toyota 4E engine to the "Engines - TOYOTA" section:

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

2026-02-01 FP Dual Carbs for the Fiat X1/9

#39593 from Daniel Snow · Rule change · TB 26-02 (2026-02 Fastrack)

unclearFP Fiat X1/9 gains dual carburetor options with 28mm side-draft alternates and revised valve/transmission specs.

In FP Spec Lines, change as follows:
Fiat X-1/9 & Bertone 1300:
"(1) Weber 32 DMTR or DATRA/100 w/32mm bores
(1) 40 DCNF w/32mm choke(s)
(2) auto-type side-draft w/28mm choke(s) on I.R. manifold
Orientation of the alternate carburetor is unrestricted. The alternate carb adapter may not be thicker than 1.25”. The adapter
may have a bore larger than the throttle bore of the approved alternate carburetor.
Valve Size: (I) 35.5/(1.40) (E) 31.3/(1.23)~~30.5/(1.20) (E) 1.23~~

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Trans. Speeds: 5"
Fiat X-1/9 & Bertone:
"Fuel Injection
(1) 34 DMTR~~, (1) 36 DCNF w/34mm choke(s), or (1) 40DCNF w/34mm choke(s)~~
(1) 36 or 40 DCNF w/34mm choke(s)
(2) auto-type side-draft w/28mm choke(s) on I.R. manifold
Orientation of the alternate carburetor is unrestricted. The alternate carb adapter may not be thicker than 1.25”. The adapter
may have a bore larger than the throttle bore of the approved alternate carburetor.
Valve Size: (I) 35.5/(1.40) (E) 33.0/(1.30)
Trans. Speeds: 5 or 4"

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