BoP Lab / Buttonwillow Raceway Park

HP + EP at Buttonwillow Raceway Park

No mapCal Club 2024, Cal Club 2023

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.

Pos	Car	Driver	Class	#	Lap	Theoretical	Qual	Race	5-lap stint	Consistency	Trap	S1	S2	S3
1	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
2	Mazda Miata	Joe Carr	EP	12	1:52.034 B-P	1:52.034	1:59.603 A-Q1	1:59.157 A-R1	1:59.373 A-R1	+0.724 A-R1	131.6 A-R1	31.719 B-P	32.405 B-P	49.966 B-P
3	Mazda MX-5	Glen McCready	EP	4	1:53.088 B-Q2	1:52.984	1:53.088 B-Q2	1:53.487 B-R2	1:54.617 B-R2	+2.232 B-R2	125.6 B-P	30.761 B-R2	32.765 B-Q1	49.458 B-Q2
4	Mazda RX-7	Kurt Frietzsche	EP	40	1:56.468 B-Q1	1:55.599	1:56.468 B-Q1	1:56.573 B-R1	1:57.721 B-R1	+1.914 B-R1	120.7 A-R2	31.324 B-Q1	34.071 B-R1	50.204 B-R1
5	Mazda RX-7	Brandon Droese	EP	02	1:56.943 B-Q1	1:56.657	1:56.943 B-Q1	1:58.611 B-R1	1:58.767 B-R1	+0.718 B-R1	94.1 B-Q1, B-R1	31.953 B-R1	33.891 B-Q1	50.813 B-Q1
6	BMW E30	Sean Lovett	EP	37	2:00.712 A-Q2	2:00.625	2:00.712 A-Q2	2:01.864 A-R2	2:02.200 A-R1	+0.528 A-R1	127.6 A-Q2	32.761 A-Q1	34.806 A-Q1	53.058 A-Q2
7	Porsche Boxster	William Robinson	EP	198	2:01.940 A-Q1	2:01.634	2:01.940 A-Q1	2:02.887 A-R1	2:03.347 A-R1	+1.312 A-R1	130.6 A-Q2	32.969 A-Q1	35.257 A-Q1	53.408 A-Q1
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	Mazda MX-5	Whitfield Gregg	EP	17	2:03.660 B-Q2	2:03.314	2:03.660 B-Q2	2:04.085 B-R1	2:05.470 B-R2	+2.529 B-R2	97.7 B-R2	33.862 B-R2	35.422 B-R1	54.030 B-Q2
11	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
12	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
13	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
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
Mazda Miata	EP	1	1:52.034Joe Carr	1:59.603Joe Carr	1:59.157Joe Carr	131.6Joe Carr	31.719Joe Carr	32.405Joe Carr	49.966Joe Carr
Mazda MX-5	EP	2	1:53.088Glen McCready	1:53.088Glen McCready	1:53.487Glen McCready	125.6Glen McCready	30.761Glen McCready	32.765Glen McCready	49.458Glen McCready
Mazda RX-7	EP	2	1:56.468Kurt Frietzsche	1:56.468Kurt Frietzsche	1:56.573Kurt Frietzsche	120.7Kurt Frietzsche	31.324Kurt Frietzsche	33.891Brandon Droese	50.204Kurt Frietzsche
BMW E30	EP	1	2:00.712Sean Lovett	2:00.712Sean Lovett	2:01.864Sean Lovett	127.6Sean Lovett	32.761Sean Lovett	34.806Sean Lovett	53.058Sean Lovett
Porsche Boxster	EP	1	2:01.940William Robinson	2:01.940William Robinson	2:02.887William Robinson	130.6William Robinson	32.969William Robinson	35.257William Robinson	53.408William Robinson
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 2023 → Cal Club 2024 2023-02-24 to 2024-02-23

2023-04-01 EP Investigate Parity of Z3

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

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

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

2023-06-01 EP 914-6 Valve Size Correction

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

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

In EP Spec Lines, Porsche 914 - 6 2.0L, change Valves IN & EX mm/(in.) as follows:
"(I) 4~~1.9~~ 2.0/(1.65)
(E) 38.1 0/(1.50)"

2023-06-01 HP Request to Classify Sonic and Fiesta in HP

#34264 from Greg Amy · Rule change · TB 23-06 (2023-05 Fastrack)

neutralFord Fiesta HP and Chevrolet Sonic FP model year ranges extended from 2016 to 2019.

In HP, adjust model years of the "Ford Fiesta (11-16)" spec line as follows:
"Ford Fiesta (11-16 9)"
In FP, adjust model years of the "Chevrolet Sonic (12-16)" spec line as follows:
"Chevrolet Sonic (12-16 9)"

2023-07-01 HP ITC to FP?

#34286 from David Snow · Rule change · TB 23-06 (2023-07 Fastrack)

neutralHP Volkswagen Rabbit Cabriolet 1780 removed; Rabbit 1588 and 1715 reclassified with engine sizes and year ranges specified.

In HP Spec Lines, Volkswagen Rabbit Cabriolet 1780, delete in its entirely:
In HP, Spec Lines, Volkswagen Rabbit, change Title as follows:
“Volkswagen Rabbit 1588 ~~(includes Cabriolet / convertible)~~”
“Volkswagen Rabbit 1715 ~~(81-84) (excl. conv.)~~”
“Volkswagen Rabbit ~~GTI~~ 1780 ~~(83-84)~~”

2023-07-01 HP Correct Intake Valve Size on 1500cc Midget/Spitfire

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

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

In FP Spec Lines, Austin-Healey Sprite Mk. I, II,III, IV MG Midget Mk I,II, III, IV & 1500, change Intake Valve Size as follows:
"(I) 36.6~~5.3~~/(1.44)"
In FP Spec Lines, Triumph Spitfire Mk. IV & 1500, change Intake Valve Size as follows:
"(I) 36.6~~5.5~~/(1.440)"
In HP Spec Lines, Triumph Spitfire 1500, change Intake Valve Size as follows:
"(I) 36.6~~5.5~~/(1.440)"
In HP Spec Lines, Triumph Spitfire Mk. III & IV 1500, change Intake Valve Size as follows:
"(I) 36.6~~5.5~~/(1.440)"

2023-07-01 EP Correct Intake Valve Size on 1500cc Midget/Spitfire

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

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

2023-09-01 EP Hub Note Clean Up In EP TR8 Spec Line

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

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

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

2023-09-01 EP Triumph GT6 Adjustments

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

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

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

2023-09-01 EP Triumph GT6 Adjustments: Brakes

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

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

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

2023-09-01 HP Larger chokes

#34681 from Brian Downey · Rule change · TB 23-09 (2023-09 Fastrack)

fasterHP Nissan/Datsun PL510 carburetors allow larger 4mm chokes, replacing 2mm specification.

In HP Spec Line, Nissan/Datsun PL510, change Carburetor. No. & Type as follows:
"(1) 40 DCN, DCNF w/ 32 4mm choke(s), . or (1) 36mm DCNVH. (2) auto type side draft(s) w/ 32 4mm choke(s) on I.R. manifold @
90lbs penalty."

2023-12-01 HP Porsche 944/924S Rule Change Request

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

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

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

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

2023-12-01 EP Porsche 944/924S Rule Change Request

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

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

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

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

2023-12-01 HP FP and HP Toyota Corolla

#35030 from Keith Church · Rule change · TB 23-12 (2023-12 Fastrack)

fasterFP Toyota Corolla 2TC loses 43 lbs to 1810; HP Corolla loses 50–52 lbs to 1910–2006.

In FP Spec Lines, Toyota Corolla 2TC (71-74), change weight as follows:
"~~1853~~ 1810"
In HP Spec Lines, Toyota Corolla (71-74), change weight as follows:
“~~1960~~ 1910
* ~~2009~~ 1958
** ~~2058~~ 2006”

2023-12-01 HP Weight Reduction for Mazda 626

#35031 from David Reiter · Rule change · TB 23-12 (2023-12 Fastrack)

fasterHP Mazda 626 84-87 weight reduced to 2200 lbs, 2255 lbs, and 2310 lbs across three configurations.

In HP Spec Lines, Mazda 626 (84-87), change weight as follows:
"~~2300~~ 2200
*~~2358~~ 2255
**~~2415~~ 2310"

2023-12-01 HP Triumph GT6 Adjustments

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

fasterEP Triumph GT6 minimum weight reduced to 1800 lbs.

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

2023-12-01 EP Triumph GT6 Adjustments

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

fasterEP Triumph GT6 minimum weight reduced to 1800 lbs.

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

2023-12-01 HP Request to Adjust Weight of 1988-1991 CRX/Civic

#35115 from Enrik Benazic · Rule change · TB 23-12 (2023-09 Fastrack)

fasterHP Honda CRX 1.5 (88-91) weight reduced to 2175 lbs, 2229 lbs, and 2284 lbs across three spec lines.

In HP Spec Lines, Honda CRX 1.5 (88-91), change weight as follows:
"~~2245~~ 2175
*~~2301~~ 2229
**~~2357~~ 2284"

2024-01-01 HP Request to Review Z3 2.5 Spec Line

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

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

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

2024-01-01 EP Request to Review Z3 2.5 Spec Line

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

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

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

2024-01-01 HP Parity in HP

#35138 from Kendall Jones · Rule change · TB 24-01 (2024-01 Fastrack)

fasterHP Sprite/Midget Mk I–IV, Mk 1500 compression ratio raised to 12.0:1 at Prep Level 1/2.

In HP Spec Line, Austin-Healey Sprite Mk I, II, III, IV / MG Midget Mk I, II, III, IV & 1500, Prep Level 1/2, change Notes section as
follows:
"Compression ratio limited to 11 12.0:1"

2024-01-01 HP Spitfire classification

#35224 from Michael Walz · Rule change · TB 24-01 (2024-01 Fastrack)

unclearHP Triumph Spitfire 1500 valve spec changes from 36.6/5.5/(1.44/0) to 36.6/(1.44).

In HP spec line, Triumph Spitfire 1500, make the following change to the Valves column:
"(I) 36.6~~5.5~~/(1.440)"

2024-01-01 HP Miata Alternate Head

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

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

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

Applies to Mazda Miata on this page: Joe Carr

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

2024-01-01 EP Miata Alternate Head

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

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

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

Applies to Mazda Miata on this page: Joe Carr

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

2024-01-01 HP Triumph GT6 Adjustments

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

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

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

2024-01-01 EP Triumph GT6 Adjustments

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

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

2024-01-01 HP Honda S2000 throttle body

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

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

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

2024-01-01 EP Honda S2000 throttle body

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

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

2024-01-01 HP Front Header/Nose Panel Alternate Material For 84-87 CRX

#35301 from Darryl Saylor · Rule change · TB 24-01 (2024-01 Fastrack)

neutralHP Honda CRX/Si 84-87 front header/nose panel may use alternate material if appearance remains stock.

In HP Spec Lines, Honda CRX/Si (84-87), in Notes, make the following change:
"Compression ratio limited to 11.0:1, Valve lift limited to .390”. The front header/nose body panel can be replaced by a
replica which may be constructed of an alternate material provided its appearance remains stock."

2024-01-01 HP Correction within Triumph TR8 Spec Line

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

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

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

2024-01-01 EP Correction within Triumph TR8 Spec Line

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

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

2024-01-01 HP Correction to EP 924S/944 Spec Line

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

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

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

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

2024-01-01 EP Correction to EP 924S/944 Spec Line

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

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

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

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

2024-01-01 HP Review Classification of HP Mazda 2

#35318 from Production Committee · Rule change · TB 24-01 (2024-01 Fastrack)

slowerHP Mazda 2 (11-14) minimum weight increases to 1995 lbs, 2045 lbs with*, 2095 lbs with**.

In HP spec line, Mazda 2 (11-14), make the following weight changes:
"~~1920~~ 1995
*~~1968~~ 2045
**~~2016~~ 2095"

2024-02-01 HP Update 1988-1991 Civic to Match 1988-1991 CRX

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

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

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

2024-02-01 EP Update 1988-1991 Civic to Match 1988-1991 CRX

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

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

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

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

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

2024-03-01 EP 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.

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."

2024-06-01 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 EP 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 EP 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.

2024-06-01 EP 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.

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)"

2024-08-01 EP 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 EP 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.

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.

2024-11-01 EP NA Miata Track Width Correction

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

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

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

2024-12-01 EP Triumph GT6 Adjustments

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

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

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

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

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

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

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"

2025-02-21 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."

2025-02-21 EP 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.

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 EP 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.

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 EP 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

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**~~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 EP 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 EP 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 EP 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”."

2025-04-01 EP 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”."

2025-06-01 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”

2025-06-01 EP 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.

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 EP 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."

2025-07-01 EP 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.

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 EP 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 EP 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)."

2025-10-01 EP 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.

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 EP 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 EP 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 EP 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 EP 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 EP 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".

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 EP 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.

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~~

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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 EP 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.

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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"

2025-11-01 EP 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 EP 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.

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"

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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 EP 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.

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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 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 EP Request to Update E30 BMW Throttle Body Diameter Verbiage

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

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

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

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

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"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.