F6 + SRF + P1 at Buttonwillow Raceway Park

2021-03-01 P1 DP02 Sealed 2ltr Engine Option

#30038 from Club Racing Board · Rule change · TB 21-01 (2021-01 Fastrack)

In P1 Engine Table, Elan DP02-spec Mazda MZR, change Notes as follows:
"Sealed engine option will be removed effective 1 3/1/2021.

2021-03-01 SRF Mandatory identification:

#30223 from Robey Clark · Rule change · TB 21-03 (2021-03 Fastrack)

In SRF, GCR section 9.1.8.E.2.B, change as follows:
"Mandatory identification: "SRF3" near the side car numbers,. Approved (2) “Ford Performance” on each sideof the engine cover
plus a Ford Blue Oval on the center of the Nose & (2) “Performance Electronics” on eachside of the tail. "Hoosier" logo (4) on
both sides front lower outer corners of the nose, and each side of the tail."

2021-03-01 P1 E&O restrictor terminology

#30285 from Formula/Sports Racing Committee · Rule change · TB 21-03 (2021-03 Fastrack)

In P1 Engine Table, Spec Line C, change the notes as follows:
"May run without inlet intake restrictor at 1150 lbs. min. weight. Up to 1355cc may run without inlet intake restrictor at 1075 lbs.
min. weight."
In P1 Engine Table, Spec Line G, change the notes as follows:
"Up to 2000cc may run with inlet intake restrictor at 1400 lbs. min. weight. Up to 2300cc may run with inlet intake restrictor at
1445 lbs. min. weight."

2021-04-01 P1 Clean up Spec Line A notes section

#30424 from Formula/Sports Racing Committee · Rule change · TB 21-04 (2021-04 Fastrack)

In P1 Engine Table, Spec Line A, change the notes as follows:
"Balance tubes not allowed. One Carb per cylinder. Carburetor induction only. One carburetor per cylinder. Restricted venturi
size. Balance tubes not allowed."

2021-04-01 P1 Clean up Spec Line H notes section

#30425 from Formula/Sports Racing Committee · Rule change · TB 21-04 (2021-04 Fastrack)

In P1 Engine Table, Spec Line H, change the notes as follows:
"Peripheral P port or Bridge Port bridgeport A allowed."

2021-05-01 P1 E&O tonneau cover provision in cockpit opening section

#30458 from Formula/Sports Racing Committee · Rule change · TB 21-05 (2021-05 Fastrack)

In P1, GCR section 9.1.8.C.C.6.c, make changes as follows:
"Allowed equipment would include batteries, ballast, fire bottles, data recording devices, and cool suit
equipment, providing provided such equipment is securely attached to the car. Tonneau covers are allowed in order to meet
minimum dimensions."

2021-05-01 P1 Update Spec Line B Notes

#30498 from Formula/Sports Racing Committee · Rule change · TB 21-05 (2021-05 Fastrack)

In P1 Engine Table, Spec Line B, change the notes as follows:
"Staudacher cars homologated before 1-1-2014 using 1005cc may run 38.5mm flat plate intake restrictor at 950 lbs.
min. weight wt."

2021-05-01 P1 Update Spec Lines C and G notes

#30499 from Formula/Sports Racing Committee · Rule change · TB 21-05 (2021-05 Fastrack)

In P1 Engine Table, Spec Line C, change the notes as follows:
"May run without intake restrictor FPIR not required at 1150 lbs. min. weight wt. Up to 1355cc max. may run without intake
restrictor FPIR at 1075 lbs. min. weight wt."
In P1 Engine table, Spec Line G, change the notes as follows:
"Up to 2000cc max. may run with intake restrictor 30mm SIR at 1400 lbs. min. weight wt. Up to 2300cc max. may run with intake
restrictor 30mm SIR at 1445 lbs. min. weight wt."

2021-05-01 P1 E&O Maximum Valves Per Cylinder

#30559 from Formula/Sports Racing Committee · Rule change · TB 21-05 (2021-05 Fastrack)

In P1 Engine Table, Spec Line B, change the maximum valves per cylinder section as follows:
"NA 4"
In P1 Engine Table, Spec Line C, change the maximum valves per cylinder section as follows:
"NA 4"
In P1 Engine Table, Spec Line D, change the maximum valves per cylinder section as follows:
"NA 4"

2021-06-01 SRF SRF3 Alternator Pulley

#30684 from Robey Clark · Rule change · TB 21-06 (2021-06 Fastrack)

In SRF, GCR section 9.1.8.E.2.H.17, add the following:
"Alternator Pulley: P/N G902130 or P/N G902130A. 12oz minimum weight"

2021-08-01 SRF SRF Wet Tires

#30849 from Robey Clark · Rule change · TB 21-08 (2021-08 Fastrack)

In SRF, GCR section 9.1.8.E.1.X.f, make changes as follows:
"Dry:
Front – Hoosier P/N 46340 P185/60ZR13 SRF
Rear – Hoosier P/N 46350 P205/60ZR13 SRF
Wet:
Front – Hoosier P/N 46100 P185/60R13 H20
Rear – Hoosier P/N 46105 P205/60R13 H20
or

2021-08-01 P1 Add 1355cc spec line

#30890 from Formula/Sports Racing Committee · Rule change · TB 21-08 (2021-08 Fastrack)

In P1 engine table, change as follows:
P1 Engine Table
Spec
Line Engine Series

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

2021-08-01 SRF SADEV-SRF3 Transmission

#30926 from Robey Clark · Rule change · TB 21-08 (2021-08 Fastrack)

In SRF, GCR section 9.1.8.E.2.K, make changes to gear ratios as follows:
"Gear Ratios:
Ford/Mazda OEM 5-Speed:
1st 3.42 : 1
2nd 1.84 : 1
3rd 1.29 : 1
4th 0.97 : 1
5th 0.77 : 1

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

2021-08-01 SRF SRF Update Maintenance, Repairs and Seals

#30961 from Robey Clark · Rule change · TB 21-08 (2021-08 Fastrack)

In SRF, GCR section 9.1.8.E.1.C, make changes as follows:
"If any official Enterprises seal is broken, by an Enterprises Customer Service Rep. (CSR) emergency field repair, accident, or
intent, the procedures outlined under C.20., section S shall be followed. Parts with an Enterprises part number having the prefix
"10" are considered to be unrestricted, providing provided their dimensions are comparable."
In SRF, GCR section 9.1.8.E.1.S, make changes as follows:
"SCCA Enterprises' seals on engine are required for all races must be present on driveline components in designated locations for
all SCCA sanctioned events. Any competitor who runs participates in an event without all proper engine seals in the required
locations shall have his engine removed and shipped to Enterprises for testing and sealing after that event must remove his

2021-09-01 P1 Move 2000cc and 2300cc engine options to individual spec lines

#31012 from Formula/Sports Racing Committee · Rule change · TB 21-09 (2021-09 Fastrack)

In P1 Engine Table, change as follows:

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

2021-09-01 P1 E&O Spec Line B notes

#31095 from Formula/Sports Racing Committee · Rule change · TB 21-09 (2021-09 Fastrack)

In P1 Engine Table, Spec Line B, change the notes as follows:
"Staudacher cars may run 950 lbs. min. wt. with 38.5mm flat plate intake restrictor at 950 lbs. min. wt."

2021-12-01 SRF Three Updates to SRF Rules

#31523 from Robey Clark · Rule change · TB 21-12 (2021-12 Fastrack)

In SRF, GCR section 9.1.8.E.1.X.f, change as follows:
"Wet:
Front – Hoosier P/N 46100 P185/60R13 H20
Rear – Hoosier P/N 46105 P205/60R13 H20
Ground clearance is 2.5" with driver as raced when H20 tires are used.
or
Front – Hoosier P/N 46100 P185/60 65R13 W2 (effective Oct. 4, 2021)
Rear – Hoosier P/N 46105 P205/60R13 W2 (effective Oct. 4, 2021)"

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

2022-01-01 P1 Displacement & Weight Change Request for 2-Cycle 6 Cylinder

#31609 from Jason Miller · Rule change · TB 22-01 (2022-01 Fastrack)

In P1 Engine Table, Spec Line A, change as follows:
P1 Engine Table
Spec
Line Engine Series Max. Displ

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

2022-05-01 P1 E&O Clarification of Bodywork Rules

#32468 from Club Racing Board · Rule change · TB 22-05 (2022-04 Fastrack)

In P1, GCR section 9.1.8.B.C.2, add the following:
"Cycle-type fenders (which that cover only the tire and are not continuous with the rest of the body) and may thereby permit a
view of the ground from above are prohibited."
In P1, GCR section 9.1.8.B.C.3, add the following:
"As viewed from the side, T the outermost surface of body between the front and rear wheel openings and above the floor must
have a minimum height equal to the height of the front axle centerline."
In P1, GCR section 9.1.8.B.D.1, add the following:
"It is not permitted to duct air through any part of the bodywork for the purpose of providing aerodynamic downforce on the

2022-06-01 SRF SRF Tire Rule Update

#32614 from Robey Clark · Rule change · TB 22-06 (2022-06 Fastrack)

In SRF, GCR section 9.1.8.D.1.X.f, change as follows:
"Tires: must be run as delivered."

2022-06-01 SRF Brake, seal, and air filter clarifications

#32670 from Club Racing Board · Rule change · TB 22-06 (2022-06 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 be used as delivered with no
machining of any kind. Minimum thickness 13.25 12.20mm (0.522 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. Rubber caliper bushings may be replaced with bronze bushings P/N 1196185 or P/N 1196185."
In SRF, GCR section 9.1.8.D.2.H, change as follows:
"No performance M modifications of any kind.
SCCA Enterprises’ seals shall be intact.

2022-08-01 P1 Clarify authorization to use flat plate intake restrictor

#32964 from Club Racing Board · Rule change · TB 22-08 (2022-08 Fastrack)

In P1, GCR section 9.1.8.B.J.7, add the following:
"On 4-cycle motorcycle-based engines equipped with individual throttle bodies, individual flat plate intake restrictors must be
installed within 4 inches of the primary butterfly throttle shaft or centerline on the intake side of the individual throttle body's
primary butterfly."

2022-10-01 P1 E&O clarification regarding forced induction

#33123 from Club Racing Board · Rule change · TB 22-10 (2022-10 Fastrack)

In P1, GCR section 9.1.8.B.J, add a new part and renumber the section accordingly:
"1. Turbocharging and supercharging are not allowed."

2022-11-01 P1 Clarify body panel coverage of suspension components

#33318 from Club Racing Board · Rule change · TB 22-11 (2022-11 Fastrack)

In P1, GCR section 9.1.8.B.D.1, add the following:
"No aerodynamic devices (e.g. "skirts," body sides) may extend more than 1cm (0.394 inches) below a lower surface anywhere
on the car to the rear of the front axle. Seat bucket or other protrusions shall not circumvent this rule. Aerodynamic devices shall
be securely mounted on the entirely sprung part of the car and not be movable when the car is in motion. It is not permitted to
duct air through any part of the bodywork for the purpose of providing aerodynamic downforce on the car. This prohibition
includes openings above the front spoiler or splitter that allow air to pass through the front bodywork for the purpose of
providing aerodynamic downforce. Body panels intended to cover suspension components as viewed from the side and above
must not be shaped as an airfoil cross-section or create a pressure differential from the action of air flowing over the upper and

2023-03-01 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;

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

2023-03-01 P1 November 2022 Rules Clarification for Suspension Covers

#33615 from Michael Devins · Rule change · TB 23-01 (2023-01 Fastrack)

In P1, GCR section 9.1.8.B.D.1, effective 3/1/23, change as follows:
"Body panels intended to cover suspension components as viewed from the side and above must not be shaped as an airfoil
cross-section or create a pressure differential from the action of air flowing over the upper and lower surfaces of the
panel. Upper and lower panel surfaces must be symmetrical (mirror images) across a straight line connecting the center of the
leading edge with the center of the trailing edge. Leading and trailing edges may be rounded. Panel angle front to rear and side
to side is unrestricted, but it is not permitted to angle the body panels for the purpose of providing aerodynamic downforce on
the car."

2023-04-01 P1 E&O - Correct dimensional equivalents

#34018 from Club Racing Board · Rule change · TB 23-04 (2023-04 Fastrack)

In P1, GCR section 9.1.8.B.C.3, change as follows:
"Height: No part of the vehicle having special or significant aerodynamic function shall exceed a height of 115cm (45.275 inches)
above the ground with car in normal racing trim, driver aboard."
In P1, GCR section 9.1.8.B.C.4, change as follows:
"However, no portion shall extend more than 10cm (3.937 inches) beyond a plane tangent to the outer face of the front and rear
wheels with tires."
In P1, GCR section 9.1.8.B.C.6.b, change as follows:
"Cockpit length: 60cm (23.662 622 inches). Cockpit width for each seat: 45cm (17.717 inches) maintained over 30cm (11.811

2023-05-01 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"

2023-06-01 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."

2023-07-01 P1 SIR Testing

#34354 from Jeff Shafer · Rule change · TB 23-06 (2023-05 Fastrack)

In P1, GCR section 9.1.8.B.J, add a new section and re-letter the following sections accordingly:
"3. The SIR testing procedure in Appendix F. Technical Glossary (Restrictor, Intake) is modified as follows: If the vehicle stalls
within 3 seconds, the vehicle is deemed compliant with the stall test."

2023-07-01 P1 E&O Single Inlet Restrictor abbreviation, etc.

#34369 from Club Racing Board · Rule change · TB 23-06 (2023-05 Fastrack)

In P1, GCR section 9.1.8.B.J.2, change as follows:
"Where a carburetor or fuel injection restriction is specified, a flat plate intake restrictor, restricted venturi, or Single Inlet
Restrictor (SIR) is required through which, all intake air for each cylinder or the entire fuel-air mixture, if prepared before this
point, shall must pass through the restrictor."

2023-07-01 P1 E&O Clean up ducted air provision

#34410 from Club Racing Board · Rule change · TB 23-06 (2023-05 Fastrack)

In P1, GCR section 9.1.8.B.D.2, change as follows:
"All ducted air that exits through the top of the bodywork behind the rear of the front tires must pass through a heat
exchanger., excluding This requirement does not apply to the cockpit opening, fender louvers, or slots, louvers, grills, and similar
devices for allowing intended to allow heat to escape the engine bay, shall pass through a heat exchanger."

2023-10-01 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."

2024-01-01 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."

2024-01-01 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."

2024-01-01 P1 Please correct omitted punctuation

#34890 from Club Racing Board · Rule change · TB 23-10 (2023-09 Fastrack)

In Cars and Equipment, GCR section 9.3.33.B.2, add the following:
"(Effective 1/1/2024) A red taillight meeting FIA Standard 8874-2019, Technical List No. 76, is required on all Formula (open
wheel) and Sports Racing cars."
In Appendix F. Technical Glossary, Minimum Weight, change as follows:
"Minimum Weight: – Weight specified with driver, exactly as they come off the race circuit, at the conclusion of any race or
qualifying session."
In FA Table 1, Spec Line E notes, add the following:
"Any BD series iron or alloy cylinder block and alternate crankshaft permitted."

2024-01-01 P1 Adjust restrictors and weights for Engine Table lines H and I

#35229 from Club Racing Board · Rule change · TB 24-01 (2024-01 Fastrack)

In P1 Engine Table, change as follows:
P1 Engine Table
Spec
Line Engine Series Max. Displ.
(cc)
Max
Valves /
Cyl.

2024-01-01 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:

2024-01-01 P1 Revise Group CN Honda K20A-FD2 Spec Line

#35337 from Formula/Sports Racing Committee · Rule change · TB 24-01 (2024-01 Fastrack)

In P1 Engine Table, Spec Line G, change as follows:
P1 Engine Table
Spec
Line Engine Series Max. Displ.
(cc)
Max
Valves /
Cyl.