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BoP Lab / Buttonwillow Raceway Park

FM + SRF + EP at Buttonwillow Raceway Park

No mapCal Club 2024, Cal Club 2023

Track map: sectors and speed trap

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

This track has been raced on 4 configurations (The Circuit, 2.57 mi; 19, 2.92 mi; 1.83 mi; 3.02 mi). Laps on different configurations are not comparable, so only events on the 2.57 mile layout are shown; switch above to see the others.

FM has no laps in the events chosen. It ran at Super Tour Apr 2019, Super Tour Apr 2018, Super Tour Apr 2017: add those events.

SRF has no laps in the events chosen. It ran at Super Tour Apr 2017, Majors Apr 2016: add those events.

PosCarDriverClass#LapTheoreticalQualRace5-lap stintConsistencyTrapS1S2S3
1Mazda MiataJoe CarrEP121:52.034 B-P1:52.0341:59.603 A-Q11:59.157 A-R11:59.373 A-R1+0.724 A-R1131.6 A-R131.719 B-P32.405 B-P49.966 B-P
2Mazda MX-5Glen McCreadyEP41:53.088 B-Q21:52.9841:53.088 B-Q21:53.487 B-R21:54.617 B-R2+2.232 B-R2125.6 B-P30.761 B-R232.765 B-Q149.458 B-Q2
3Mazda RX-7Kurt FrietzscheEP401:56.468 B-Q11:55.5991:56.468 B-Q11:56.573 B-R11:57.721 B-R1+1.914 B-R1120.7 A-R231.324 B-Q134.071 B-R150.204 B-R1
4Mazda RX-7Brandon DroeseEP021:56.943 B-Q11:56.6571:56.943 B-Q11:58.611 B-R11:58.767 B-R1+0.718 B-R194.1 B-Q1, B-R131.953 B-R133.891 B-Q150.813 B-Q1
5BMW E30Sean LovettEP372:00.712 A-Q22:00.6252:00.712 A-Q22:01.864 A-R22:02.200 A-R1+0.528 A-R1127.6 A-Q232.761 A-Q134.806 A-Q153.058 A-Q2
6Porsche BoxsterWilliam RobinsonEP1982:01.940 A-Q12:01.6342:01.940 A-Q12:02.887 A-R12:03.347 A-R1+1.312 A-R1130.6 A-Q232.969 A-Q135.257 A-Q153.408 A-Q1
7Mazda MX-5Whitfield GreggEP172:03.660 B-Q22:03.3142:03.660 B-Q22:04.085 B-R12:05.470 B-R2+2.529 B-R297.7 B-R233.862 B-R235.422 B-R154.030 B-Q2

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

Sectors

Sectors are numbered in lap order from start/finish, whatever each event's timing called them; the loop names are SCCA timing's.

By car

CarClassDriversLapQualRaceTrapS1S2S3
Mazda MiataEP11:52.034Joe Carr1:59.603Joe Carr1:59.157Joe Carr131.6Joe Carr31.719Joe Carr32.405Joe Carr49.966Joe Carr
Mazda MX-5EP21:53.088Glen McCready1:53.088Glen McCready1:53.487Glen McCready125.6Glen McCready30.761Glen McCready32.765Glen McCready49.458Glen McCready
Mazda RX-7EP21:56.468Kurt Frietzsche1:56.468Kurt Frietzsche1:56.573Kurt Frietzsche120.7Kurt Frietzsche31.324Kurt Frietzsche33.891Brandon Droese50.204Kurt Frietzsche
BMW E30EP12:00.712Sean Lovett2:00.712Sean Lovett2:01.864Sean Lovett127.6Sean Lovett32.761Sean Lovett34.806Sean Lovett53.058Sean Lovett
Porsche BoxsterEP12:01.940William Robinson2:01.940William Robinson2:02.887William Robinson130.6William Robinson32.969William Robinson35.257William Robinson53.408William Robinson

The best any driver of each car managed across the selected events, with who set it. Spellings and model years of the same car are grouped; click a row marked ▸ to see each version. Grouping is worked out from the names, so tell us if two cars are wrongly merged or split.

Rule changes between these events

Cal Club 2023 → Cal Club 2024 2023-02-24 to 2024-02-23

SRF Update SRF Brake Rule

#33469 from Robey Clark · Rule change · TB 23-01 (2023-01 Fastrack)

In SRF, GCR section 9.1.8.D.X.g, change as follows:
"Brakes: Hawk Blue 9012 pads P/N 801993 must be used. Wilwood vented rotor P/N 800065 shall be used as delivered with no
machining of any kind. Minimum thickness 12.20mm (0.481"). The 1985 Renault Alliance solid front rotor (Reference: Bendix
PRT1318 or Centrix 121.11004) may be used on front, rear, or both axles, but each axle must be paired to the same type
rotor. The Renault Alliance solid front rotors may not be used. Rubber caliper bushings may be replaced with bronze bushings P/N
1196185 or P/N 1196185. Original caliper pistons may be replaced with vented caliper piston P/N 1196184; no other
modification allowed. Wilwood caliper with bracket universal fit P/N 800038 may be used as delivered with no modification of
any kind. Wilwood knock back spring (2.63 lbs.) P/N 800045 may be used as delivered with no modification of any kind;

Show 4 more lines

maximum of one spring per caliper."
P2 Engine Table
Spec
Line Engine Series

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

EP Investigate Parity of Z3

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

slower · inductionEP BMW Z3 2.5L flat plate intake restrictor reduced from 58mm to 56mm, both throttle bodies.
As printed in Fastrack

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

SRF Update SRF Front W2 Rain Tire Part Number

#34118 from Robey Clark · Rule change · TB 23-05 (2023-05 Fastrack)

In SRF, GCR section 9.1.8.D.1.X.f, change as follows:
"Front – Hoosier P/N 46100 1 P185/65R13 W2"

EP 914-6 Valve Size Correction

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

faster · engineEP Porsche 914-6 2.0L intake valve increased to 2.0 mm, exhaust valve corrected to 38.0 mm.
As printed in Fastrack

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

SRF Hoosier SRF Wet Front Tire Rule Update

#34189 from Robey Clark · Rule change · TB 23-06 (2023-06 Fastrack)

In SRF, GCR section 9.1.8.D.1.X.f, change as follows:
"Wet:
Front – Hoosier P/N 46100 P185/60R13 H20 or W2
Rear – Hoosier P/N 46105 P205/60R13 H20 or W2
Ground clearance is 2.5" with driver as raced when P185/60R13 (H20 or W2) tires are used."

EP Correct Intake Valve Size on 1500cc Midget/Spitfire

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

wordingFP and HP Sprite and Spitfire 1500 intake valve size corrected to 36.6 mm, removing prior decimal specifications.
As printed in Fastrack

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

EP Hub Note Clean Up In EP TR8 Spec Line

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

removedEP Triumph TR8 78-81 removes allowance for alternate front hubs of same external dimensions and weight.
As printed in Fastrack

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

EP Triumph GT6 Adjustments

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

engineEP Triumph GT6 carburetor type changes from SU or Stromberg to Auto-type, quantity two 1.5 inch.
As printed in Fastrack

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

EP Triumph GT6 Adjustments: Brakes

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

added · suspension & brakesEP Triumph GT6 Brakes Alt. now permits TR-6 standard or alternate calipers and discs.
As printed in Fastrack

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

SRF SRF Radiator Rule Update

#34805 from Robey Clark · Rule change · TB 23-10 (2023-10 Fastrack)

In SRF, GCR section 9.1.8.D.1.V.j, change as follows:
"Radiator - Enterprises new style P/N 480465 (requires baffle P/N 480464) or P/N 480466 can be used. P/N 480466, may can be
replaced with Automotive P/N 1R698, CU698 or equivalent OEM manufacturer justified by one cross-reference chart equivalent,
as long as the size, shape, and material are the same as the original P/N. The capacity, core thickness, etc., cannot be changed
even if allowed under the above. The competitor is responsible for providing this documentation of the cross-reference P/N."

EP Porsche 944/924S Rule Change Request

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

slower · weightEP Porsche 944/924S combines 2.5L and 2.7L variants (83-89), raises weight to 2250–2415 lbs, allows 2681cc displacement.
As printed in Fastrack

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

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

EP Triumph GT6 Adjustments

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

faster · weightEP Triumph GT6 minimum weight drops to 1800 lbs.
As printed in Fastrack

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

SRF Update SRF Rain / Brake Rule

#34706 from Robey Clark · Rule change · TB 23-09 (2023-09 Fastrack)

In SRF, GCR section 9.1.8.D.1.W.l, change as follows:
"A Super Bright LEDs Inc. rain / brake light comprised of a single standard trailer oval lamp, 2-1/4 inches x 6-1/2 inches, with
incandescent or LED illumination, P/N PT-STRB-R24, is required in the original roll hoop mounting location. This rule supersedes
GCR section 9.3.32.B.2 effective 1/1/2024 through 12/31/2024. No changes may be made to the original 3-pin connector on the
wiring harness. The secondary filament of the brake light assembly shall must be connected to a switch enabling its use as a rain
light."

SRF Update SRF Brake Light Rule v1

#34853 from Robey Clark · Rule change · TB 23-10 (2023-10 Fastrack)

In SRF, GCR section 9.1.8.D.1.W.l, change as follows:
"A Super Bright LEDs Inc. P/N PT-STRB-R24 (SCCA Enterprises P/N 180427A) rain / brake light, P/N PT-STRB-R24, is required in the
original roll hoop mounting location. This rule supersedes GCR section 9.3.32.B.2 effective 1/1/2024 through 12/31/2024. No
changes may be made to the original 3-pin connector on the wiring harness. An SCCA Enterprises P/N 1190503 Strobing Brake
Light Pigtail is required. The secondary filament of the brake light assembly must be connected to a switch enabling its use as
a strobing rain light. A Strobing Brake Light Kit P/N 1168003 is available, which includes the brake light and pigtail."

EP Request to Review Z3 2.5 Spec Line

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

slower · weightEP BMW Z3 2.5L minimum weight increased to 2500 lbs, 2563 lbs with power adder, 2625 lbs with two power adders.
As printed in Fastrack

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

EP Miata Alternate Head

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

faster · weightEP Mazda MX-5 1.8L (90-97) minimum weight cut to 2150 lbs; (94-97) variants to 2000, 2050, 2100 lbs.
As printed in Fastrack

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

Applies to Mazda Miata on this page: Joe Carr

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

EP Triumph GT6 Adjustments

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

slower · weightEP Triumph GT6 dual 1.75-inch carburetors weight rises to 1940 lbs; triple Weber 40 DCOE option added at 1990 lbs.
As printed in Fastrack

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

SRF SRF / SRF3 Rule Updates

#35268 from Robey Clark · Rule change · TB 24-01 (2024-01 Fastrack)

In SRF, GCR section 9.1.8.D.1.H, add the following:
"NO MODIFICATIONS ALLOWED. Front brake ducts are required, attached to the openings in the lower radiator baffles, any
flexible 4" duct material allowed, installed length minimum 12" maximum 36" in length. Must be securely fastened, Bracket Part
# P/N 800368 can be used. Shall Must serve no other purpose. An extension may be welded to the side of the throttle pedal to
improve heel-and-toe braking. Master cylinder casting / location must be used as delivered on P/N 180110 Pedal Mounting
support. Aeroquip style -3 braided stainless flex lines only, must attach to all brake components without modification. Brake pad
"anti-rattle" clips must be removed."
In SRF, GCR section 9.1.8.D.1.V, add the following:

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"ii. Rear SADEV shift cable aluminum two-piece style clamp may be used. The P/N WM302007A clamp must serve no other
purpose."
In SRF, GCR section 9.1.8.D.1.X.k, add the following:
"Negative camber shall must not exceed 5.0 degrees absolute maximum front and rear."
In SRF, GCR section 9.1.8.D.1.AA.b, add the following:
"2. Height of the radiator opening vertical surface 3 1/2“ +/- 1/2"."
P2 Engine Table B.1
2008 and older Stock
Suzuki, Yamaha,
Honda, BMW
38.5mm
P2 Engine Table B.2 Not required
P2 Engine Table B.3 38.5mm
Modified
Engine
950 lbs.
1005cc max
P2 Engine Table B.1
2008 and older 37mm
P2 Engine Table B.2 Not required
P2 Engine Table B.3 39mm
Stock Engine
1050 lbs.

EP Honda S2000 throttle body

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

faster · inductionEP Honda S2000 fuel injected throttle body inside diameter increases from 62mm to 64mm.
As printed in Fastrack

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

EP Correction within Triumph TR8 Spec Line

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

wordingEP Triumph TR8 dry sump allowance moved from Carburetor line to Notes.
As printed in Fastrack

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

EP Correction to EP 924S/944 Spec Line

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

weightEP Porsche 944/924S 2.5L and 2.7L minimum weights corrected: 2479cc to 2306–2363 lbs, 2681cc to 2358–2415 lbs.
As printed in Fastrack

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

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

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

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

faster · weightHP Honda Civic 1.5 1988-91 minimum weight drops 70 lbs to 2175; also 2-speed and 3-speed minimums cut 72 and 73 lbs.
As printed in Fastrack

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

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

EP GCR Correction - Redundant HP Spec Lines

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

removedHP removes four redundant VW spec lines: Rabbit Cabriolet 1780, Scirocco 1588, Scirocco 1780 8-valve 83-88, Scirocco 1588.
As printed in Fastrack

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

EP NIssan 300ZX Z31 to EP

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

addedNissan 300ZX 84–89 added to EP, 2550–2678 lbs, 2960 cc SOHC, fuel injection, 12.0:1 compression, 0.500" valve lift limit.
As printed in Fastrack

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

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

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

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

addedMazda RX-7 92-97 added to EP Prep as Level 2 rotary 13B 6-port, 2200–2310 lbs, carb or fuel injection, 42 mm choke.
As printed in Fastrack

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

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

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

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

removed · cars addedEP Mazda RX-8 (04-11) alternate spec line removed; single spec line retained.
As printed in Fastrack

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

EP Errant entry in HP production line item

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

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

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

SRF Update Rain Tire Rule and Hoosier Decal Placement

#36436 from Robey Clark · Rule change · TB 24-08 (2024-08 Fastrack)

In SRF, GCR section 9.1.8.D.1.X.f, change as follows:
"Wet:
Front – Hoosier P/N 46100 P185/60R13 H20 or W2
Rear – Hoosier P/N 46105 P205/60R13 H20 or W2
Ground clearance is 2.5” with driver as raced when P185/60R13 (H20 or W2) tires are used.
OR
Front – Hoosier P/N 46101 P185/65R13 W2
Rear – Hoosier P/N 46105 P205/60R13 W2

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1. It is forbidden to regroove tires.
2. The use of tire warmers or cooling methods other than natural air convection or conduction is prohibited. The penalty for
violation will be the loss of qualifying times and/or the disqualification of race results.
3. Hoosier SRF/SRF3 Decal Placement:
Four (4) "Hoosier" decals are required in the following locations: Two (2) 11" X 3" decals on the vertical plane of the front nose to
the outside of the cooling opening on each side and two (2) 18" X 5" decals, one on each side of the engine cover or above the
rear wheel openings on the vertical plane. Hoosier decals are available, free of charge, from all Hoosier tire distributors including
SCCA Enterprises."

SRF Protest Fee Clarification

#36540 from SCCA Staff · Rule change · TB 24-09 (2024-09 Fastrack)

In FE, GCR section 9.1.1.I.2.U.b.3, change as follows:
"Protest Fee: Regional -$25.00, National -$50.00. See GCR section 8.3.1.D for fees and payment procedure."
In SRF, GCR section 9.1.8.D.1.U.b.3, change as follows:
"Protest Fee: Regional -$25.00, National -$50.00. See GCR section 8.3.1.D for fees and payment procedure. Item 1 will be done by
the CSR or other shop that is equipped for this type of work and will be paid directly."

SRF Update to Letter 36619 with new Hoosier Contingency Decal Info

#36624 from Robey Clark · Rule change · TB 24-09 (2024-09 Fastrack)

In SRF, GCR section 9.1.8.D.1.X.f.3, change as follows:
"Four (4) "Hoosier" decals are required in the following locations: Two (2) 11" X 3" decals on the vertical plane of the front nose
to the outside of the cooling opening on each side and two (2) 18" X 5" decals, one on each side of the engine cover or above the
rear wheel openings on the vertical plane. Hoosier decals are available, free of charge, from all Hoosier tire distributors including
SCCA Enterprises Per Hoosier's contingency program, three (3) decals are required to qualify for contingency awards. One (1)
decal must be located on each side of the car and one (1) decal must be visible on the front."

SRF Update SRF3 Air Filter Rule

#36681 from Robey Clark · Rule change · TB 24-10 (2024-10 Fastrack)

In SRF, GCR section 9.1.8.D.2.H.23, change as follows:
"Air Filter: P/N WM301020 or K&N RC-9160"

SRF Update SRF Brake Rotor Thickness

#36687 from Robey Clark · Rule change · TB 24-10 (2024-10 Fastrack)

In SRF, GCR section 9.1.8.D.1.X.g, change as follows:
"Brakes: Hawk Blue 9012 pads P/N 801993 must be used. Wilwood vented rotor P/N 800065 shall must be used as delivered with
no machining of any kind. Minimum thickness 12.20mm (0.481”) 13.25mm (0.522”)."

SRF Hoosier Tire Decal Placement

#36739 from Robey Clark · Rule change · TB 24-10 (2024-10 Fastrack)

In SRF, GCR section 9.1.8.D.2.B, change as follows:
"Mandatory identification: "SRF3" near the side car numbers. "Hoosier" logo (4) on both sides front lower outer corners of the
nose and each side of the tail. Three (3) "Hoosier" logos, one (1) on each side of the car and one (1) on the center front of the car."

EP 1275 HP Spridget Level 2 Only

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

faster · engineHP 1275 Spridget compression ratio raised to 12.0:1; 1098cc also raised to 12.0:1.
As printed in Fastrack

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

EP NA Miata Track Width Correction

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

otherEP Miata 1.6L, 1.8L 90–97, and 94–97 track width corrected to 1516/1534 mm (59.7/60.4 in.) front and rear.
As printed in Fastrack

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

EP Triumph GT6 Adjustments

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

faster · inductionEP Triumph GT6 switches to three Weber 40 DCOE carburetors with 28mm chokes, weight rises to 1990 lbs.
As printed in Fastrack

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

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)

faster · weightEP BMW 325i/is E30 84-91 weight reduced to 2150 lbs base, 2204 lbs with turbo, 2258 lbs supercharged.
As printed in Fastrack

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

EP Effective date for Jan 2025 GCR updates

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

slower · inductionEP BMW models now require flat plate intake restrictors: Z3 2.5L 52mm, Z3 2.8L 55mm, 328i E36 58mm, 328i/ci E46 58mm, 325i E46 56mm, 325i E36 56mm, 325is M-Technic 56mm.
As printed in Fastrack

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

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

EP Request Competition Adjustment to BMW Z3 2.5L

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

slower · inductionEP BMW Z3 2.5L, Z3 2.8L, 328i E36/E46, 325i E36/E46 intake restrictors reduced 4mm each, to 52–58mm.
As printed in Fastrack

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

EP Interpretation of Production Rules on Mirrors

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

addedEP, FP, HP may use any interior or exterior mirror meeting rule 9.3.36.
As printed in Fastrack

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

EP Weight Reduction for Honda S2000

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

faster · weightEP Honda S2000 1997cc minimum weight drops 75 lbs to 2375; 2157cc drops 60 lbs to 2450.
As printed in Fastrack

In EP, Spec Lines make the following weight changes:

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

EP Mazda 1999 Miata 1.8L

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

faster · weightEP Mazda MX-5 Miata 99-05 minimum weight reduced to 2100 lbs, 2153 lbs with power, 2205 lbs modified.
As printed in Fastrack

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

EP Request for Classification of Chevrolet Spark

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

addedChevrolet Spark 16-22 classified in HP Pre at 1850 lbs base, 1896 lbs modified, 1943 lbs.
As printed in Fastrack

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

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

EP Request to Lower Ford Festiva Minimum Weight to 1600 LBS

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

faster · weightHP Ford Festiva 88-93 minimum weight lowered to 1600 lbs, competition weight to 1640, prepared weight to 1680; compression ratio raised to 11.0:1.
As printed in Fastrack

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

SRF Driver Safety & Comfort

#37966 from Robey Clark · Rule change · TB 25-04 (2025-04 Fastrack)

In SRF, GCR section 9.1.8.D.1.D, add the following:
"f. Driver Safety and Comfort modifications to seat and controls for drivers with disabilities may be made only by approval. These
modifications must be reported to SCCA Enterprises and noted in the car logbook. The modifications are approved only for the
noted driver with disabilities. If the car is used by or sold to another driver, it must be returned to the previous standard
configuration."

SRF Update SADEV transmission specs

#37992 from Club Racing Board · Rule change · TB 25-04 (2025-04 Fastrack)

In SRF, GCR section 9.1.8.D.2.K, change as follows:
"OR
SADEV-SRF3 6-Speed Sequential (beginning from Oct. 4, 2021 onward):
1st 12-36 3.0000 : 1
2nd 15-31 2.0667 : 1
3rd 18-28 1.5556 : 1
4th 22-28 1.2727 : 1
5th 24-26 1.0833 : 1

Show 2 more lines

6th 25-23 0.9200 : 1
Final Drive Ratio: 15-48 3.20"

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

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

faster · weightHP Fiat X-1/9 and Bertone 1500 minimum weights reduced to 1740 lbs, 1784 lbs, 1827 lbs; 1300 models to 1600, 1640, 1680 lbs; additional 1300 and 1500 specs to 2010, 1900 lbs.
As printed in Fastrack

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

EP BMW Z4 update

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

slower · inductionEP BMW Z4 03-05 gains 52mm flat plate intake restrictor.
As printed in Fastrack

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

EP EP Fiat 124 Spider Competition Adjustment Request

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

faster · weightEP Fiat 124 Spider Competition 1600 and 2000 minimum weight drops 50 lbs to 2000; carburetors now allow 36mm chokes instead of 34mm.
As printed in Fastrack

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

SRF Add HD Oil Cooler

#38979 from Robey Clark · Rule change · TB 25-10 (2025-10 Fastrack)

In SRF, GCR section 9.1.8.D.1.V.ff, change as follows:
"SRF3 Oil Cooler, P/N G480503 or HD Oil Cooler P/N G1148500 may be used as mounted per the GEN3 Assembly Manual. No fan
permitted for SRF. HD Oil Cooler kit P/N G1148500 may be used as mounted per the GEN3 Conversion Manual."

EP HP Plymouth Arrow spec omission

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

addedHP Plymouth Arrow gains 4 or 5 speed transmission option specification.
As printed in Fastrack

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

EP Add Wheel Diameter to Appendix G

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

wordingAppendix G.2.3 clarifies rim width and diameter are absolute maximums; wording corrected from 'is' to 'are'.
As printed in Fastrack

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

EP Add TB ID tolerance to general Prod rules

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

addedEP, FP, HP throttle body inside dimensions and butterfly now allow +/-.25mm tolerance from stock.
As printed in Fastrack

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

EP Please Lower Weight of 280Z

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

faster · weightEP Nissan 280Z minimum weight lowered to 2400 lbs, 2460 lbs with *, 2520 lbs with **.
As printed in Fastrack

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

EP Miata Weight Adjustment Follow Up

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

faster · weightEP Mazda MX-5 1.8L 90-97 minimum weight reduced to 2125 lbs.
As printed in Fastrack

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

EP Weight Break for 1098 Midget / Sprite

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

faster · weightHP Spec Lines Austin-Healey Sprite/Midget 1098cc minimum weight drops to 1550 lbs.
As printed in Fastrack

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

EP HP Volvo 142 spec omission

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

slower · engineHP Volvo 142 P-1800 engine gains compression ratio limit 12.0:1 and valve lift limit .425 inch.
As printed in Fastrack

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

EP HP Mini DOHC 1.6

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

slower · engineHP Mini DOHC 1.6 valve lift limit drops to .390" from .450".
As printed in Fastrack

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

EP Add to Rabbit description

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

wordingFP and HP Volkswagen Rabbit descriptions updated to clarify Cabriolet body style inclusion.
As printed in Fastrack

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

EP Clean-up 9.1.5.E.7e

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

otherEP, FP, HP: rear drum-to-disc brake conversion clarified; rotors solid, diameter limited to largest front rotor permitted.
As printed in Fastrack

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

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

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

added · inductionEP Ford Mustang 94-98 fuel injected throttle body inside diameter set to 60.
As printed in Fastrack

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

EP TR2 Notes E&O

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

wordingEP Triumph TR2–TR4A may use 5-speed gearbox without overdrive; Weber carburetors and weight reference deleted.
As printed in Fastrack

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

EP Balance of Power

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

slower · inductionEP BMW Z3 2.5L and other models get smaller restrictors, 50mm to 55mm, and Z3 2.5L weight rises 50 to 78 lbs.
As printed in Fastrack

In EP Spec Lines, make the following changes to Restrictors:
BMW Z3 2.5L: "52mm 50mm Flat Plate Intake Restrictor"
BMW Z3 2.8L (97-00): "55mm 53mm Flat Plate Intake Restrictor"
BMW 328i/is E36 (96-99): "58mm 55mm Flat Plate Intake Restrictor"
BMW 328i/ci E46 (01-06): "58mm 55mm Flat Plate Intake Restrictor"
BMW 325i/is (E46) (01-06): "56mm 53mm Flat Plate Intake Restrictor"
BMW 325is M-Technic (1994): "56mm 53mm Flat Plate Intake Restrictor"
BMW 325i/is E-36 (92-95): "56mm 53mm Flat Plate Intake Restrictor"
In EP Spec Lines, BMW Z3 2.5L, change Weight as follows:
"2500 2550
*2563 2614
**2625 2678"

EP Request to Update E30 BMW Throttle Body Diameter Verbiage

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

wordingEP BMW 325i/is E30 fuel injection throttle body specified as 60mm diameter.
As printed in Fastrack

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

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