BoP Lab / Buttonwillow Raceway Park

HP + P + P2 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	Elan DP02/Mazda	Jim Devenport	P	23, 28	1:32.576 A-P	1:32.284	1:32.872 B-Q2	1:33.972 B-R2	1:35.195 B-R1	+1.742 B-R1	171.9 A-P	25.461 B-Q2	26.606 A-P	40.217 A-P
2	Dauntless Stohr	Johnnie Crean	P	3, 135	1:36.516 B-Q1	1:36.516	1:36.516 B-Q1	1:39.209 B-R1	1:40.027 B-R1	+1.943 B-R1	157.4 B-P	25.956 B-Q1	28.143 B-Q1	42.417 B-Q1
3	Stohr WF1	Tim Day Jr	P2	8	1:37.278 A-Q1	1:37.278	1:37.278 A-Q1	1:39.758 A-R2	1:40.037 A-R2	+1.010 A-R2	155.4 A-R2	26.848 A-Q1	28.010 A-Q1	42.420 A-Q1
4	Dauntless-Stohr P07d	John Manfroy	P	08	1:37.287 A-R2	1:36.339	1:41.818 A-Q1	1:37.287 A-R2	1:39.027 A-R2	+2.902 A-R2	160.4 A-R2	26.696 A-R2	27.257 A-R2	42.386 A-R2
5	Stohr WF1	Kevin Mitz	P	13	1:38.716 A-Q2	1:38.667	1:38.716 A-Q2	1:39.638 A-R2	1:40.087 A-R2	+0.641 A-R2	155.4 A-Q1	26.934 A-Q2	28.397 A-Q2	43.336 A-Q2
6	Penton Norma M20FC	Joseph Moran	P	7	1:39.296 A-Q2	1:38.868	1:39.296 A-Q2	1:40.832 A-R1	1:42.328 A-R1	+3.544 A-R1	149.0 A-Q2	27.106 B-Q1	28.111 A-Q1	43.651 A-Q1
7	MG Midget	Bill Okell	HP	7	1:40.295 B-P	1:40.261	2:07.503 B-Q1	2:04.195 A-R2	2:04.781 A-R2	+2.144 A-R2	116.4 B-P	27.543 B-P	28.857 B-P	43.861 B-P
8	MG Midget	Lee Fleming >115%	HP	00	2:03.082 B-R1	2:00.418	2:05.170 A-Q1	2:03.082 B-R1	2:04.295 A-R1	+1.090 A-R1	126.2 A-R2	30.556 A-Q1	35.463 B-R1	54.399 A-R1
9	MG Midget	Brian Linn >115%	HP	48	2:03.551 A-R1	2:03.219	2:04.965 A-Q1	2:03.551 A-R1	2:04.243 A-R1	+0.928 A-R1	121.0 A-R1	33.172 A-R1	35.274 A-R1	54.773 A-R1
10	MG Midget	Noel Hayward >115%	HP	2	2:04.870 B-R2	2:04.711		2:04.870 B-R2	2:10.679 B-R1	+4.104 B-R1	99.2 B-R2	33.577 B-R2	36.471 B-R2	54.663 B-R2
11	Toyota Yaris	Bobby Beyer >115%	HP	18	2:08.224 B-R2	2:08.010	2:10.927 B-Q1	2:08.224 B-R2	2:09.636 B-R2	+2.098 B-R2	92.3 B-R2	34.660 B-R2	37.206 B-R2	56.144 B-R2
12	Mini Cooper	Tom Tuttle >115%	HP	42	2:09.238 B-R2	2:08.416	2:11.042 B-Q1	2:09.238 B-R2	2:10.173 B-R1	+1.249 B-R1	99.0 B-R2	34.631 B-R1	37.306 B-R1	56.479 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
Elan DP02/Mazda	P	1	1:32.576Jim Devenport	1:32.872Jim Devenport	1:33.972Jim Devenport	171.9Jim Devenport	25.461Jim Devenport	26.606Jim Devenport	40.217Jim Devenport
Dauntless Stohr	P	2	1:36.516Johnnie Crean	1:36.516Johnnie Crean	1:37.287John Manfroy	160.4John Manfroy	25.956Johnnie Crean	27.257John Manfroy	42.386John Manfroy
Dauntless Stohr	P	1	1:36.516Johnnie Crean	1:36.516Johnnie Crean	1:39.209Johnnie Crean	157.4Johnnie Crean	25.956Johnnie Crean	28.143Johnnie Crean	42.417Johnnie Crean
Dauntless-Stohr P07d	P	1	1:37.287John Manfroy	1:41.818John Manfroy	1:37.287John Manfroy	160.4John Manfroy	26.696John Manfroy	27.257John Manfroy	42.386John Manfroy
Stohr WF1	P/P2	2	1:37.278Tim Day Jr	1:37.278Tim Day Jr	1:39.638Kevin Mitz	155.4Tim Day Jr	26.848Tim Day Jr	28.010Tim Day Jr	42.420Tim Day Jr
Penton Norma M20FC	P	1	1:39.296Joseph Moran	1:39.296Joseph Moran	1:40.832Joseph Moran	149.0Joseph Moran	27.106Joseph Moran	28.111Joseph Moran	43.651Joseph Moran
MG Midget	HP	4	1:40.295Bill Okell	2:04.965Brian Linn	2:03.082Lee Fleming	126.2Lee Fleming	27.543Bill Okell	28.857Bill Okell	43.861Bill Okell
Toyota Yaris	HP	1	2:08.224Bobby Beyer	2:10.927Bobby Beyer	2:08.224Bobby Beyer	92.3Bobby Beyer	34.660Bobby Beyer	37.206Bobby Beyer	56.144Bobby Beyer
Mini Cooper	HP	1	2:09.238Tom Tuttle	2:11.042Tom Tuttle	2:09.238Tom Tuttle	99.0Tom Tuttle	34.631Tom Tuttle	37.306Tom Tuttle	56.479Tom Tuttle

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 HP 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

2024-05-01 P2 CN Spec ECU

#35835 from Bart Wolf · Rule change · TB 24-05 (2024-05 Fastrack)

neutralP2 Spec ECU engine modifications clarified: oil system, ECU, and exhaust unrestricted only.

In P2 Engine Table, Spec Line E, change the notes as follows:
"No engine modifications except f~~or dry sump oil system, ECU mapping, and exhaust system~~ the following: oil system, ECU, and
exhaust are unrestricted."

2024-05-01 HP Replace plastic panels

#35875 from Darryl Saylor · Rule change · TB 24-05 (2024-05 Fastrack)

neutralHP Honda CRX/Si 84-87 plastic panels can be replaced with replica alternate material if stock appearance maintained.

In HP spec line "Honda CRX/Si (84-87)", make the following change 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 P2 E&O - Correct FIA Group CN spec line notes

#35900 from Club Racing Board · Rule change · TB 24-05 (2024-05 Fastrack)

neutralP2 FIA Group CN spec notes clarified: Series changed to Challenge, documentation requirement moved to online link.

In P2 Table 1, FIA Group CN spec line, change the notes as follows:
"FIA Group CN homologated chassis, brake calipers and discs, hub carriers, and suspension components are required. V de
V European Proto Endurance ~~Series~~ Challenge permitted bodywork, rear diffuser, wing, wheels, and assisted
shifting are allowed. Car M must comply with all other P2 requirements. ~~Competitors must have copies of~~ FIA Group CN
Technical Regulations and V de V European Proto Endurance ~~Series~~ Challenge Sporting and Technical Regulations ~~in their~~
~~possession and present them upon request~~ are available here: https://www.scca.com/pages/technical-forms-and-downloads."

2024-06-01 HP 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 HP 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 HP 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 HP 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)"

2024-11-01 HP 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"

2024-11-01 HP Request for Classification of 1989-1994 Suzuki Swift GT 16V Twin

#36858 from Jorge Fabian · Rule change · TB 24-11 (2024-11 Fastrack)

neutralSuzuki Swift GT 89-94 newly classified to HP Pre at 1900 lbs, 1298cc DOHC fuel injected.

In HP Spec Lines, Classify Suzuki Swift GT (89-94) as follows:

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

2024-12-01 HP MINI Cooper Spec Line Correction - Rear Brake Rotor Diameter

#37176 from Robert Bax · Rule change · TB 24-12 (2024-12 Fastrack)

neutralHP Mini Cooper 02-06 rear brake rotor increases from 239/9.4 mm/in to 259/10.2.

In HP Spec Lines, Mini Cooper (02-06), change Brakes Std.mm/(in.) as follows:
"(F) 276/(10.9) Vented Disc (R) ~~239/(9.4)~~ 259/(10.2) Solid Disc"

Applies to Mini Cooper on this page: Tom Tuttle

2024-12-01 P2 2000 cc Pinto Engine Car Weight

#37187 from Marvin Hodges · Rule change · TB 24-12 (2024-12 Fastrack)

slowerP2 2000cc Pinto engine car minimum weight set to 1335 lbs.

In P2 Engine Table, Line E Note 2, add the following:
"8. Minimum weight 1335 lbs."

2025-01-01 HP 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 HP Request to Update 1988-1991 Civic to Match 1988-1991 CRX

#37444 from ENRIK BENAZIC · Rule change · TB 25-01 (2025-01 Fastrack)

fasterHP Honda Civic 1.5 88-91 weight reduced to 2175 lbs base, 2229 lbs with one asterisk, 2284 lbs with two asterisks.

In HP SPEC LINES, Honda Civic 1.5 (88-91), change Weight as follows:
"~~2245~~ 2175
*~~2301~~ 2229
**~~2357~~ 2284"

2025-02-01 P Correct text in engine table notes

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

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

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."

2025-02-01 P Update Prototype class designation

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

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

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:

Show 20 more lines

"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, F~~B, 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:"

2025-02-21 HP 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 HP 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 HP 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 HP HP Class Adjustments

#37459 from Production Committee · Rule change · TB 25-01 (2025-01 Fastrack)

slowerHP Mazda 2 11-14 base weight up 50 lbs to 2045; all VW 80s models up 50 lbs to 2150 base.

In HP SPEC LINES, change Weight as follows:
Mazda 2 (11-14)
"(Effective 3/1/2025) ~~1995~~ 2045
*~~2045~~ 2096
**~~2095~~ 2147"
Volkswagen Golf (GTI, GT, GL) (85-92)
"(Effective 3/1/2025) ~~2100~~ 2150
*~~2153~~ 2204

Show 13 more lines

**~~2205~~ 2258"
Volkswagen Jetta (GLI, GL) (85-92)
"(Effective 3/1/2025) ~~2100~~ 2150
*~~2153~~ 2204
**~~2205~~ 2258"
Volkswagen Rabbit 1780
"(Effective 3/1/2025) ~~2100~~ 2150
*~~2153~~ 2204
**~~2205~~ 2258"
Volkswagen Scirocco 1780 (8-valve) (83-88)
"(Effective 3/1/2025) ~~2100~~ 2150
*~~2153~~ 2204
**~~2205~~ 2258"

2025-03-01 HP 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 HP 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 HP MINI Cooper (07-13) Spec Line Correction: Errors and Omissions

#37560 from Robert Bax · Rule change · TB 25-03 (2025-03 Fastrack)

slowerHP Mini Cooper 07-13 engine corrected to DOHC; valve lift limit reduced to 0.390 inches.

In HP Spec Lines, Mini Cooper (07-13) (includes 09-15 convertible and 12-15 Coupe), change as follows:
Engine Type:
"4 Cyl
~~SOHC~~ DOHC"
Notes:
"Compression ratio limited to 11.0:1, Valve lift limited to ~~.450”~~.390"."

Applies to Mini Cooper on this page: Tom Tuttle

2025-04-01 HP 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 HP 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 P Add missing punctuation marks

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

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

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:

Show 3 more lines

"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."

2025-06-01 HP 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 HP 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 HP 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."

2025-08-01 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)

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

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

2025-09-01 P 13B Rotary Engine Rules Change Request

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

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

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"

2025-09-01 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)

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

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

2025-09-01 P Clarify spec line cars language

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

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

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.

2025-10-01 HP 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 HP 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 HP 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 HP 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 HP 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 HP 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 HP 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 HP 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 HP 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 HP 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~~

Show 3 more lines

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

2025-11-01 HP 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"

2025-12-01 HP Request to Re-Classsify Datsun SPL-311 to HP from FP

#39116 from Robert Heatwole · Rule change · TB 25-12 (2025-12 Fastrack)

neutralDatsun SPL-311 newly classified to HP at 2050 lbs with 1595cc OHV iron engine and specified carburetors.

In HP Spec Lines, classify Nissan/Datsun SPL 311 as follows:

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

2025-12-01 HP 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 HP 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"

Show 4 more lines

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

2025-12-01 HP Alternative BOP Request for 84-87 Honda CRX/Civic

#39223 from Bill Lamkin · Rule change · TB 25-12 (2025-12 Fastrack)

fasterHP Honda Civic and CRX models get wider 13-inch wheels: 6 to 7 inches.

In HP Spec Lines, change Wheels as follows:
Honda Civic: "13 x 6 7"
Honda Civic DX (92-95): "13 x 6 7"
Honda Civic/Si (84-87): "13 x 6 7"
Honda Civic 1.5 (88-91): "13 x 6 7"
Honda CRX/Si (84-87): "13 x 6 7"
Honda CRX 1.5(88-91): "13 x 67"

2026-01-01 P Request to Continue to Allow Carbon Brakes

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

neutralPrototype carbon-carbon and carbon-ceramic brake rotors now permitted instead of prohibited.

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."

2026-01-01 HP E/O: Improve Consistency of the Spec Lines

#39500 from Robert Bax · Rule change · TB 26-01 (2026-01 Fastrack)

unclearHP Toyota MR-2 1.6L (85-89) compression ratio set to 11.0:1.

In HP Spec Line, Toyota MR-2 1.6L (85-89), change Comp. Ratio as follows:
"11.0:1"

2026-01-01 HP Request to Reclassify BMW 2002 Into H Production

#39567 from Jonathan Kinberg · Rule change · TB 26-01 (2026-01 Fastrack)

neutralBMW 2002 newly classified to H Production at 2350 lbs with 1990cc iron block, 40 DCNF carburetor, 11.0:1 compression.

In HP Spec Lines, classify BMW 2002, as follows:

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

2026-02-01 HP Triumph Spitfire 1296cc Compression Ratio Increase to 12:1

#39589 from Neil Verity · Rule change · TB 26-02 (2026-02 Fastrack)

fasterHP Triumph Spitfire 1296cc compression ratio increases from 11.0 to 12.0:1.

In HP Spec Lines, make the following spec line changes:
Triumph Spitfire:
Carburetion
"Valves: (I) 33.0/(1.30) (E) 29.7/(1.17)
Comp. ratio ~~11.0~~ 12.0:1, Valve lift .450”
Trans. Speeds: 4"
Triumph Spitfire Mk. III & IV 1500:
Carburetion

Show 5 more lines

"1300 Valves: (I) 33.0/(1.30) (E) 29.7/(1.17)
1500 Valves: (I) 36.6/(1.44) (E) 29.7/(1.17)
1300: Comp. ratio 12.0:1, Valve lift .450”
1500: Comp. ratio 11.0:1, Valve lift .450”
Trans. Speeds: 4"

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