FE + SRF + GT1 at Buttonwillow Raceway Park

In GT1 Cars - Mercedes Benz, classify Mercedes Benz AMG GT3 as follows:
GT1 Cars – MERCEDES BENZ
Model Years Body Style Drive-

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

In GT1, GCR section 9.1.2.D.7.a., change as follows and renumber:
"1. Wheels shall be made of steel, aluminum, magnesium, or a combination thereof. Multi-piece wheels shall utilize mechanical
fasteners (bolts, rivets, etc.) for assembly.
2. Wheels may be thirteen (13), fourteen (14), fifteen (15), sixteen (16), seventeen (17), or eighteen (18) inches in diameter, but
all four (4) wheels shall be of the same diameter. Use of eighteen (18) inches wheels must add 50 lb. weight penalty.
3. 1.Wheels shall have a maximum width of twelve (12) inches in the front and thirteen (13) inches in the rear. 18” tires shall
have thirteen (13) MAX inches in the front and fourteen (14) MAX inches in the rear."

In FE, GCR section 9.1.1.I.2.M, change as follows:
"Tires must be run as delivered in sets of 4 as stated below:"

In FE, GCR section 9.1.1.I.2.K.c, change as follows:
"Master cylinders must be the Girling type:
Girling F front master cylinder is .700" piston diameter, Part # WM802005
Girling R rear master cylinder is .750" piston diameter, Part # WM802006"

In GT1 Category Specifications, GCR Section 9.1.2.D.8.a. add the following:
"7. Current Trans Am bodywork is allowed with a 100lb. weight penalty."

In GT, GCR Section 9.1.2.F.7.a.6:
"Glass and/or plastic headlights, front parking lights, front signal lights, lenses, and bulbs shall be removed. Headlight openings
shall be covered with a wire mesh screen or panel having the same contour as the original lens, mounted so that the headlight
bezel/rim remains in place, maintaining the standard appearance of the Production automobile. Side marker light assemblies
shall be removed and the resulting openings covered with a plate whose dimensions do not exceed those of the original parts;
side marker lights that are an integral part of the taillight assembly cannot be removed. Other lighting parts and operating
mechanisms may be removed. In the case of pop-up headlights, the entire assembly may be removed and the opening covered
with a screen or plate (as above, without the headlight bezel/rim requirement) which provides a stock appearance. It is not
permitted to relocate the standard headlight, parking light, signal light, etc., openings. Traditional GT cars only. Not allowed with
any "Spec Car, GT2-ST, or any other added non Traditional GT car. Taillights shall be in the original location and shall may be the
original style/type of taillight for the make, model, and year of car. A rear body panel having the same contour as the original
lens area and in the original location, may be fitted with a tail-light graphic of the original style/type frame/lens adhered to it. If
side marker lights are an integral part of the tail-light assembly they must be represented by the panel graphic. These
panel/graphics shall have a functioning red LED lamp assembly fitted through them on both sides of the car to serve as brake
lights. A 15-watt or equivalent rain light may be included with-in this LED assembly or may be a separately mounted single or
dual LED assembly."

In FE, GCR section 9.1.1.I.2.G.a.17, change as follows:
"A heat shield and heat insulation material may be used between the engine block and the exhaust system and is recommended
for the purpose of protecting hoses, shifter cable, and wiring from the heat of the engine and exhaust. Heat insulation material
may also be used to protect the fuel cell, fuel filter, fuel rail, and fuel lines."

In FE, GCR section 9.1.1.I.2.K, add the following:
"f. Driver adjustable manual brake bias is allowed."

In FE, GCR section 9.1.1.I.2.F.g, change as follows:
"The front wing main plane, front wing secondary elements, front wing support mounts, and front wing endplates assembly and
its related mounting components must be used and mounted as delivered from Enterprises. Any m Modifications to these parts,
except as specifically noted herein, is strictly forbidden are prohibited. The front main wing plane angle is zeroed on the rear
upper aft transmission surface measured with a suitable angle gauge, i.e.: digital level on the top main plane 2 inches outward
from the nose box mounts element may be adjusted +2.5 to -0.5 degrees. It must meet a minimum measurement of negative .5
degrees (angled down in the back) and a maximum measurement of positive 2.5 degrees (angled up in the back). It is acceptable
to shim the main plane to obtain this measurement. Shimming 2 of the 4 verticals through the main element mounting points to
achieve adjustment range is allowed. The main element angle is measured relative to the reference plane. The main element is
checked on the upper surface, midway between the vertical mounting and outer secondary elements on both sides. Note: The
reference plane is the machined surface where the shock clevises are attached to the transmission case. Secondary wing
elements may be used in any of the provided adjustment holes. Gurney flaps (0.500" +/- 0.030") are permitted allowed as an
option for installation on the trailing edge upper surface of the front wing on secondary elements only, not the wing main
plane. They Gurney flaps must be securely attached in a secure fashion, without modification to the wing element except for
mounting hardware. Only .500” +/- .030” flaps are allowed. Maximum number of mounting locations on front flaps is 2 on each
flap and maximum hardware size is with two #8 (.156) hardware or tape. Gurney flaps, where attached, shall be are bent or
formed 90 degrees to have a sharp inner radiusand parallel to the upper surface of the wing element and. no t Tapered or "saw-
toothed" Gurneys flaps are not permitted. Gurney flaps are measured for total height as mounted from the upper surface of the
element."
In FE, GCR section 9.1.1.I.2.F.h, change as follows:
"The rear wing assembly and its related mounting components are to must be used and mounted as delivered. Any
m Modifications, except as specifically notedherei n, are strictly prohibited. The lower plane angle, zeroed on the rear upper aft
transmission surface, measured with a suitable angle gauge. i.e.; digital level on the top surface of the lower rear wing must
meet a minimum of –3.0 degrees (angled down in the back) and a maximum of +2.0 degrees (angled up in the back). It is
acceptable to adjust the lower rear element to meet these requirements element may be adjusted +2.0 to -3.0
degrees. Chamfering the upper inner corners of the wing mounting brackets to achieve the adjustment range is allowed. The
element angle is measured relative to the reference plane. The element is checked on the top surface, near the center, without a
Gurney flap. Note: The reference plane is the machined surface where the shock clevises are attached to the transmission
case. The upper rear wing element may only be adjusted within the parameter profile of the wing endplates and wing adjusters
as provided from Enterprises using any of the provided adjustment holes. No additional holes may be added. Gurney
flaps (0.250" +/- 0.030") are permitted allowed as an optionfor installation on the trailing edge upper surface of the on one or
both wing elements. They Gurney flaps must be securely attached in a secure fashion, without modification to the wing element
except for mounting hardware. Only .250” +/- .030” flaps are allowed on one or both elements with five #8 hardware or
tape.The Gurney flaps only, may extend beyond the parameters of the end plate are bent or formed 90 degrees to have a sharp
inner radius. Maximum number of mounting locations is 5 and maximum hardware size is #8 (.156). Gurney flaps, where degrees
and parallel to the upper surface of the wing element and no t Tapered or "saw-toothed"
Gurneys flaps are not permitted. Gurney flaps are measured for total height as mounted from the upper surface of the element."

In GCR Appendix L-TA2 rules, Addendum A, change A.2. as follows:
"The throttle body must be either a GM 90mm, electronic, part #1257 → 0790, or Edelbrock 90mm, mechanical, part 33869 or
#3870."
In GTA, GCR Section 9.1.2.G.3., change as follows:
"The throttle body must be either a GM 90mm, electronic, part #1257 → 0790, or Edelbrock 90mm, mechanical, part 33869 or
#3870."

In Grand Touring 1 (GT1) Specifications, GCR Section 9.1.2.D.8.a.7., change as follows:
"Current Trans Am bodywork is allowed with a 100 75lb. weight penalty."

In GT1 (GT1) Specifications, GCR Section 9.1.2.E.1.b.1., change as follows:
"Chevrolet/GM - RO7 + 50 25 lbs.
Ford - FR9 + 50 25 lbs.
Dodge - R7 + 50 25lbs."

In GCR 9.1.2 Grand Touring 1 (GT1) Specifications, Section 9.1.2.D.4.b.2, change as follows:
"Sequential shifting transmissions are permitted with a 50 25lb. weight penalty."

In GT1-ST Spec Lines, Cars - Porsche, classify Porsche 992 GT3 Cup Car as follows:
GT1-ST Maximum
Displacement
Minimum
Weight Restrictor Notes
Porsche 992 GT3 Cup 3997 2950 Car must be prepared in accordance with
the appropriate model/year Porsche 992
factory service manual. Factory (OEM
manufactured) Lexan front windows
allowed as delivered. ABS permitted.

In GT1-ST Spec Lines, Mercedes Benz AMG GT3 (16-19), change Notes as follows:
"Car must be prepared to per its FIA GT3 homologation. except as specified differently within the GT1 class rules."

In FE, GCR section 9.1.1.I.2.G.b.4.b, change as follows:
"(All SADEV ratios are under review and could be updated prior to sealing date)"

In GT Spec Lines, GT1 Cars - Fields Cardinal, classify Fields Cardinal V8 as follows:
GT1 Cars – Fields Cardinal
Model Years Body Style Drive-
line
Wheel-
base (in)
Notes
Fields Cardinal V8 2023 2 Dr. RWD 92.0 Roll Cage MUST be modified to comply with
GCR Section 9.4.
In GT Spec Lines, GT1Engines - classify Ford V8 as follows:
GT1 Engines - Ford
Engine
Family
Engine Type Bore x

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

from the current (or before) Table of Contents (TOC), to what is shown in the after TOC.
GTL spec lines will now be contiguous with GT2 and 3 spec lines.
GTA category and spec lines will be moved and renumbered behind GTL. GTA Section will not change but page numbers will, (as
shown in Red italics).
9.1.2.F. GT-2, 3, LITE Category Specifications 314
GT2 Cars 327
GT2/ST 341
GT3 Cars 348
GTL Cars 364
GTA Cars 377
P2 Engine Table B.1
2010 and older
Stock Kawasaki
38.5mm
minimum width 52 inches. AMAC-AM5:
minimum width 54 inches.
P2 Engine Table B.1
2008 and older
Stock Engine 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 37mm
P2 Engine Table B.2 Not required
P2 Engine Table B.3 39mm
Stock Engine
1050 lbs.

In FE, GCR section 9.1.1.I.2.N.f, change as follows:
"Any rain light is allowed. Effective 1/1/2024, a rain light that meets FIA Standard 8874-2019, Technical List No. 76, is required as
specified in GCR section 9.3.32.B.2."

In GT1-ST Spec Lines, classify Lamborghini Huracan GT3 EVO(1) (2018-) as follows:
GT1-ST Maximum Displacement Minimum Weight Restrictor Notes
Lamborghini Huracan
GT3 EVO(1)
(2018-)
5204 3000 2 X39mm Per FIA Homologation
GT3-040
In GT1-ST Spec Lines, classify Lamborghini Huracan GT3 (2019-) as follows:
GT1-ST Maximum Displacement Minimum Weight Restrictor Notes
Lamborghini
Huracan GT3
2019-
5204 3100 52mm Per FIA Homologation
GT3-040

In GCR, Section 9.1.2.D.1.e.3., add at the end of section add the follows:
"Trick Flow Specialties Ultra 18 Degree GM Cylinder Head assembly Part #TFS-3181T001-CO1 is allowed."

In FE, GCR section 9.1.1.I.2.P.c, add the following:
"Racer's tape may be used to repair crash damage, or as a precautionary means of securing the body panels or
retaining latches fasteners only. Crash-damage is defined as having occurred during the current event, and the tape should be of
an appropriate color if possible. Taping of body seams is not allowed. Taping across heat exchanger openings as a way to control
temperature is allowed and may serve no other purpose."

In GCR Section 9.1.2.G (GTA Category Specifications), change as follows:
“9.1.2.G.III.I
The single-plane rear spoiler must be mounted at an angel angle from 50 to 75 degrees (perpendicular to the ground
being 90 degrees) and may not extend beyond the rear bumper when viewed from directly above the rear
bumper. Spoilers must be a minimum of .063 aluminum or Lexan and may vary in overall height to match the contours
of the bodywork. The rear spoiler dimensions shall not exceed 59.0 inches wide by 5.0 inches in height, (measured on
the material surface) , or 295.0 square inches total surface area. Braces to prevent spoiler deflection are allowed, but
may serve no other purpose.”

In GCR, Section 9.1.2.F.7.5.E. change as follows:
“Direct Injection is not permitted only if it came OE and must be installed using only OE high pressure pump(s), hard and
soft hoses and injectors.”

In GT2/3 modify Spec Line notes as follows:
GT2:
Nissan: “Direct Injection not permitted, may be used per 9.1.2.F.7.5.E.”
GT3:
Mazda: “Direct Injection not permitted, may be used per 9.1.2.F.7.5.E.”
Mitsubishi 4G93: “Direct Injection not permitted, may be used per 9.1.2.F.7.5.E. ”
Nissan QR25DE/DD 1988cc: “Direct Injection not permitted, may be used per 9.1.2.F.7.5.E.”
Nissan QE25DE/DD 2489cc: “Direct Injection not permitted, may be used per 9.1.2.F.7.5.E.”

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

In GCR, Section 9.1.2.E.1.b.3., change as follows:
"Camaro (1993-2002)"

In FE, GCR section 9.1.8.I.2.M, add the following:
"b. Hoosier FE/FE2 Decal Placement:
Five (5) "Hoosier" decals are required in the following locations: One (1) small "Hoosier" decal on the nose or the front shock
cover of the car. One (1) 12" "Hoosier" decal on the outside vertical plane of each front wing plate. One (1) 12" "Hoosier" decal
on the vertical plane of each of the lower floor panels just in front of the rear wheels. Hoosier decals are available, free of charge,
from all Hoosier tire distributors and SCCA Enterprises."

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."

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."

In FE, GCR section 9.1.1.I.2.M.b, change as follows:
"Five (5) "Hoosier" decals are required in the following locations: One (1) small "Hoosier" decal on the nose or the front shock
cover of the car. One (1) 12" "Hoosier" decal on the outside vertical plane of each front wing plate. One (1) 12" "Hoosier" decal
on the vertical plane of each of the lower floor panels just in front of the rear wheels. Hoosier decals are available, free of
charge, from all Hoosier tire distributors and 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."

In GT1 Spec Lines, GT1 Approved Automobile List, Mazda, add the following:
"(Effective 11/1/2024) 26B engine = 2850 lbs."

In GT1-ST Spec Lines, Lamborghini Huracan GT3 EVO(1) (2018-), change Restrictor as follows:
"2 X 39mmUnrestricted"
In GT1-ST Spec Lines, Lamborghini Huracan GT3 (2019-), change Restrictor as follows:
"52mm Unrestricted"

In FE, GCR section 9.1.1.G.2.K, add the following:
"g. If used, SCCA Enterprises Part # WM803010 Brake Line to Control Arm covers must be used as delivered and must be securely
fastened with zip ties/tie straps or tape. Part # WM803010 is the only approved part and may serve no other purpose."

In GCR, Section 9.1.2. GT1 Spec Lines, GT1 Approved Automobile List, LS1 V8 engine allowed with stock intake, add the
following:
"LS1 Limited Prep GT1 motor
2600 # with driver
Blocks : GM castings or aftermarket, no lightening, Max volume 383 cubic inches
Cylinder Heads: GM LS castings or aftermarket, stock valve angle, intake and exhaust ports must be in stock location, porting
and polishing allowed
Valves: No titanium valves, must be stock size for head part number
Rockers: Factory 1.7 rockers only, aftermarket trunion mod allowed
Pushrods: Free
Intake manifold: stock EFI for variant used or GM 525 carb intake or Edelbrock carb variants ie: Performer RPM, Victor, Victor Jr.
or similar.
Camshaft: Hydraulic roller only, standard journal size, lift and duration free
Timing chain: single or double roller type only
water pump: stock or aftermarket in stock location
Harmonic dampener: SFI approved,
Pistons: Factory or aftermarket flat top pistons only, valve reliefs allowed, coatings allowed
Crankshaft: Factory or forged steel aftermarket, 50 lb min. weight
Rods: GM stock or aftermarket forged steel
Carburetor: one 4150 type 750 cfm max"

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

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

In GT1-ST SPEC LINES, change as follows:
Aston Martin Vantage GT3 (2012) :
Restrictor: "2 x 41.5mm"
Audi R8 LMS Ultra GT3 (10-14) :
Restrictor: "2 x 49mm"
BMW Z4 GT3 (10-13):
Restrictor: "70mm"
Chevrolet Corvette C8 (20-):
Restrictor: "71mm- Flat Plate"
Dodge Viper GT3R (2012-):
Restrictor: "2 x 40mm"
Dodge Viper, incl Comp Coupe, ACR/ACR-X Max Displacement 8400, Weight 3200:
Restrictor: "68mm flat plate"
Ferrari 458 GT3 (2011-):
Restrictor: "2 x 43mm"
Lamborghini Gallardo GT3 (2013):
Restrictor: "2 x 47mm"
Lamborghini Huracan GT3 EVO(1) (2018-):
Restrictor: "2 X39mm"
McLaren MP12C GT3 (2013-):
Restrictor: "2 x 36mm 1.50 bar"
Lamborghini Huracan GT3 (2019-):
Restrictor: "2 x 40 mm"
McLaren MP12C GT3 (2013-):
Restrictor: "2 x 40 mm"
Mercedes Benz SLS GT3 (2011-):
Restrictor: "2 x 36 mm"
Porsche 991 GT3-R (2016):
Restrictor: "(2) 35 mm"
Porsche 997 GT3 R (2013-):
Restrictor: "65mm"

In GT1 Spec Lines, GT 1 Cars - ACURA, classify Acura NSX GT3 EVO 22 as follows:
GT 1 Cars - ACURA
Model Years Body Style Drive-
line
Wheel-
base (in)
Notes
Acura NSX GT3 EVO 22 N/A 2dr RWD 103.5 Ground Clearance 50mm
In GT1 Spec Lines, GT 1 Engines - ACURA, classify Crossflow V-6 as follows:
GT 1 Engines - ACURA
Engine
Family
Engine Type Bore x

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

Effective 9/1/25 in FE, GCR section 9.1.1.G.1.A, change as follows:
"Definition
FE’s with the Mazda 2.0L MZR engine will be classed as “FE2” and will use the class designation FE2. The Mazda 2.0L MZR motor
can be used in all SCCA events. It shall run under all FE Preparation rules except as noted below:
a. 2.0L MZR may be run with an Elite 5SPD or a Complete SADEV 6SPD transmission Kit
Must use the following:
b. 2.0L only Intake Manifold Part # WM30106
c. Throttle Body Part # WM591930-Jenvey
d. PE ECU Kit Part # 1192012
e. Nippon-Denso Alternator Part # WM902127
f. Oil Filter Adaptor Part # WM301050 & Oil Filter Part # G301022
g. PCV Valve Part # WM391502
h. The car shall weigh 1270 lbs. minimum, including the driver.
i. 16” MAZDA logo on each side of the engine cowling and the Mazda wing & name logo on the front center of the nose cone.
These are mandatory decals.
j. 2.0L MZR required Spark Plug Part# ND ITV 24
Formula Enterprises cars "FE" with Mazda 2.0L MZR engine are classed as "FE2." FE2 is the primary class in all SCCA events and
must run under all FE Preparation rules except as noted below:
Mandatory items
16” MAZDA logo, each side of the engine cowling, Mazda wing logo, front center of the nose cone.
Table 2 (Spec Line Cars)
Car Engine
Wheel
Width
(in)
± .060
Aero Transmission Weight Notes

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

In GCR, Section 9.1.2. GT1 Spec Lines, GT1 Approved Automobile List, LS1 engine allowed with stock intake, make the following
change:
"LS1 Limited Prep GT1 Motor Chevy LS Limited Prep Engine including LS1, LS2, LS3 and LS6."
"Pistons: Factory or aftermarket flat top pistons only, valve reliefs allowed, coatings allowed. Maximum compression ratio
11:1."

In FE, GCR section 9.1.1.G.2.F.k, change as follows:
"Enterprises bubble tail P/N: WM138014 is allowed for FE and is the only configuration for FE2."

IN GT1 reclassify the Acura NSX GT3 EVO 22 to GT1-ST as follows:
GT1 Approved Automobile List
Make/Model Wheelbase
ACURA
NSX GT3 EVO 22 103.5”
DOHC 4v per cylinder EFI Twin Turbo Crossflow V-6 Displacement 3500cc Bore and Stroke 91x90
MAX RPM 7500 MAX BOOST 2.1 bar Weight 3100 lbs
GT1-ST Maximum
Displacement
Minimum
Weight Restrictor Notes
ACURA NSX GT3 EVO 22 3500cc 3100 Per FIA Homologation GT3-047

In GT1-ST, Acura NSX GT3 EVO 22, change Weight as follows:
"3100 3000"

In FE, GCR section 9.1.1.G.2.G.a.1, add the following:
"NO MODIFICATIONS ARE ALLOWED EXCEPT WHERE SPECIFICALLY AUTHORIZED WITHIN THESE RULES. This includes all fuel
injection and engine management components, including exhaust, cooling, electrical and lubrication systems. All systems are
subject to test procedures and must conform to OEM / SCCA Enterprises specifications as stated and supplied by Enterprises. All
fluids, except fuel, are unrestricted."
In FE, GCR section 9.1.1.G.2.T, add the following:
"If a competitor refuses to give their engine and/or unlabeled parts for testing per a request of the Class Compliance Chief (CCC)
or Chief Steward, the following penalties will automatically be imposed:"
In FE, GCR section 9.1.1.G.2.T.d, add the following:
"The car and drivetrain are suspended from competition until the unit(s) specified by the CCC or Chief Steward are replaced."
In FE, GCR section 9.1.1.G.2.T, add a new section as follows:
"g. Any drivetrain part found to be out of spec, during voluntary or involuntary inspection, will constitute a Drivetrain Violation.
Penalties may be assessed post event."

In 9.1.2. GT1 Spec Lines, add the following:
"992.1 GT3 Cup (2022-2025)
OEM ABS and Traction Control allowed. Porsche OEM RSR bumper and canards allowed. Any exhaust system may be utilized."