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.
5 laps are left out as timing errors (far too short to be a lap of this track). The rest of those sessions, sectors included, is used.
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
Stohr WF1
P/P2
2
1:09.928Tim Day Jr
1:09.928Tim Day Jr
1:39.638Kevin Mitz
155.4Tim Day Jr
26.848Tim Day Jr
28.010Tim Day Jr
42.420Tim Day Jr
Stohr WF1
P/P2
2
1:09.928Tim Day Jr
1:09.928Tim Day Jr
1:39.638Kevin Mitz
155.4Tim Day Jr
26.848Tim Day Jr
28.010Tim Day Jr
42.420Tim Day Jr
Stohr WF1 (2004)
P2
1
1:12.573Kevin Mitz
1:12.573Kevin Mitz
Formula Enterprise
FE2
1
1:12.402Blake Pigeon
1:12.402Blake Pigeon
SCCA Ent FE2
FE2
7
1:13.988John Yeatman
1:13.988John Yeatman
1:39.712Paul Marino
156.6Paul Marino
27.234Paul Marino
28.582Paul Marino
43.028Jon McClintock
SCCA Ent FE2 (2007)
FE2
1
1:13.988John Yeatman
1:13.988John Yeatman
SCCA Ent FE2 (2010)
FE2
1
1:14.003Thomas W Burt
1:14.003Thomas W Burt
SCCA Ent FE2
FE2
5
1:39.265Jon McClintock
1:39.265Jon McClintock
1:39.712Paul Marino
156.6Paul Marino
27.234Paul Marino
28.582Paul Marino
43.028Jon McClintock
Elan DP02/Mazda
P
1
1:32.576Jim Devenport
1:32.872Jim Devenport
1:33.972Jim Devenport
171.9Jim Devenport
25.461Jim Devenport
26.606Jim Devenport
40.217Jim Devenport
Dauntless Stohr
P
2
1:36.516Johnnie Crean
1:36.516Johnnie Crean
1:37.287John Manfroy
160.4John Manfroy
25.956Johnnie Crean
27.257John Manfroy
42.386John Manfroy
Dauntless Stohr
P
1
1:36.516Johnnie Crean
1:36.516Johnnie Crean
1:39.209Johnnie Crean
157.4Johnnie Crean
25.956Johnnie Crean
28.143Johnnie Crean
42.417Johnnie Crean
Dauntless-Stohr P07d
P
1
1:37.287John Manfroy
1:41.818John Manfroy
1:37.287John Manfroy
160.4John Manfroy
26.696John Manfroy
27.257John Manfroy
42.386John Manfroy
Penton Norma M20FC
P
1
1:39.296Joseph Moran
1:39.296Joseph Moran
1:40.832Joseph Moran
149.0Joseph Moran
27.106Joseph Moran
28.111Joseph Moran
43.651Joseph Moran
Lamborghini Huracan GT3 Evo
GT1
1
1:39.857Michael McAleenan
1:39.857Michael McAleenan
1:41.045Michael McAleenan
167.6Michael McAleenan
27.368Michael McAleenan
29.135Michael McAleenan
42.926Michael McAleenan
Jaguar XKR
GT1
1
1:39.901Michael Lewis
1:39.901Michael Lewis
1:41.635Michael Lewis
151.5Michael Lewis
27.895Michael Lewis
28.765Michael Lewis
43.241Michael Lewis
Mazda RX-7
GT1
1
1:53.007Michael Lewis
1:53.007Michael Lewis
110.9Michael Lewis
30.700Michael Lewis
32.429Michael Lewis
49.385Michael Lewis
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
GT1 Mercedes AMG GT3 Notes
#33804 from Gary D'Abate · Rule change · TB 23-04 (2023-04 Fastrack)
neutralGT1 Mercedes AMG GT3 16-19 preparation wording changed to per FIA GT3 homologation.
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."
P2 Remove redundant effective date language and update engine table
#34012 from Club Racing Board · Rule change · TB 23-04 (2023-04 Fastrack)
neutralP2 engine table wording updated; redundant effective date language removed.
In P2 Engine Table, Spec Line B.1, change as follows:
P2 E&O - Correct dimensional equivalents
#34038 from Club Racing Board · Rule change · TB 23-04 (2023-04 Fastrack)
slowerP2 motorcycle engines: 2011+ Kawasaki restrictor reduced to 34mm, minimum weight raised to 1100 lbs; 2009+ other brands weight raised to 1100 lbs.
In P2, GCR section 9.1.8.C.D.2, 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 the car in normal racing trim, driver aboard." In P2, GCR section 9.1.8.C.D.3, 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." P2 Engine Table Spec
Show 1 more lines
Line Engine Series
A specification table follows in the original; it is not shown here.
GT1 Please classify Fields Cardinal V8
#33784 from James Rogersn · Rule change · TB 23-05 (2023-05 Fastrack)
neutralFields Cardinal V8 classified in GT1 with Ford V8 engine, 4.9L displacement, 2100 lbs minimum weight.
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
Show 6 more lines
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.
P2 Clarify minimum side body height requirement
#34143 from Club Racing Board · Rule change · TB 23-05 (2023-05 Fastrack)
neutralP2 side body height requirement clarified: outermost surface between wheel openings must equal front axle centerline height.
In P2, GCR section 9.1.8.C.D.6, change as follows: "As viewed from the side, T the outermost surface of side pods 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."
P2 Clarify closed cockpit single seat car allowance
#34144 from Club Racing Board · Rule change · TB 23-05 (2023-05 Fastrack)
neutralP2 closed cockpit single seat cars now prohibited unless specifically allowed in Table 1.
In P2, GCR section 9.1.8.C.C, add a section as follows: "4. Closed cockpit single seat cars are not permitted unless specifically allowed by a spec line in Table 1."
GT1 Errors in GTCS Headings and Use of the Terms Category and ClassChange existing GTL and GTA Rules
#34453 from David Gomberg · Rule change · TB 23-12 (2023-12 Fastrack)
neutralGTL spec lines moved to contiguous position with GT2 and GT3; GTA category and spec lines renumbered and moved behind GTL.
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
P2 Correct Table 1 for Engine Date Range Specifications
#35182 from Formula/Sports Racing Committee · Rule change · TB 23-12 (2023-09 Fastrack)
neutralP2 Table 1 corrects engine date ranges and brand specifications for Stock and Modified engines across multiple car models.
In P2 Table 1, change as follows: P2 Table 1 (Spec Line Cars)
A specification table follows in the original; it is not shown here.
GT1 Request for Acceptance of Lamborghini Huracan GT3 in GT1-ST
#34929 from Michael McAleenan · Rule change · TB 24-01 (2024-01 Fastrack)
neutralLamborghini Huracan GT3 EVO(1) and GT3 added to GT1-ST at 3000 and 3100 lbs minimum weight respectively.
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:
Show 6 more lines
GT1-ST Maximum Displacement Minimum Weight Restrictor Notes Lamborghini Huracan GT3 2019- 5204 3100 52mm Per FIA Homologation GT3-040
GT1 Cylinder heads
#35040 from Pater Mumford · Rule change · TB 24-01 (2024-01 Fastrack)
neutralGT1 Trick Flow Specialties Ultra 18 Degree GM Cylinder Head Part #TFS-3181T001-CO1 allowed.
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."
P2 E&O - Clarify B.1 modified engine range in AMAC spec lines
#35225 from Club Racing Board · Rule change · TB 24-01 (2024-01 Fastrack)
neutralP2 AMAC modified engine range clarified to 2008 and older stock engines only, restrictor 38mm, weight 1025 lbs.
In P2 Table 1, change as follows: P2 Table 1 (Spec Line Cars)
A specification table follows in the original; it is not shown here.
P2 Replacement Engine Crankcase for 07/08 Suzuki GSX-R1000 Engines
#35340 from Michael A Reupert · Rule change · TB 24-01 (2024-01 Fastrack)
unclearP2 Suzuki GSX-R1000 07/08 engine crankcase may swap to GSX-S1000 16/19 part #11301-04840.
In P2 Engine Table, Spec Line B.1, add to notes as follows: "No modifications allowed on engines manufactured after 2008 model year. 2007-2008 Suzuki GSX-R1000 crankcase part #11300-21860 may be replaced with 2016-2019 Suzuki GSX-S1000 crankcase part #11301-04840."
fasterGT1, GT2, GT3, GTL, GTX rear spoiler maximum surface area limit of 295.0 square inches removed.
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.”
GT1 GT Direct Injection allowance and rules
#35437 from Grand Touring Committee · Rule change · TB 24-02 (2024-01 Fastrack)
fasterGT1/GT2/GT3/GTL/GTX Direct Injection now permitted if OE, using only OE pump, hoses, injectors.
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.”
GT1 GT2/3 remove Direction Injection not allowed in Spec line notes
#35439 from Grand Touring Committee · Rule change · TB 24-02 (2024-02 Fastrack)
fasterGT2/3 Nissan, Mazda, Mitsubishi 4G93, QR25DE/DD, QE25DE/DD Direct Injection now permitted per 9.1.2.F.7.5.E.
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.”
Cal Club 2024 → Cal Club 2025 2024-02-23 to 2025-02-22
In P2 Engine Table, Spec Line E, change the notes as follows: "No engine modifications except for dry sump oil system, ECU mapping, and exhaust system the following: oil system, ECU, and exhaust are unrestricted."
P2 E&O - Correct FIA Group CN spec line notes
#35900 from Club Racing Board · Rule change · TB 24-05 (2024-05 Fastrack)
neutralP2 FIA Group CN spec notes clarified: Series changed to Challenge, documentation requirement moved to online link.
In P2 Table 1, FIA Group CN spec line, change the notes as follows: "FIA Group CN homologated chassis, brake calipers and discs, hub carriers, and suspension components are required. V de V European Proto Endurance Series Challenge permitted bodywork, rear diffuser, wing, wheels, and assisted shifting are allowed. Car M must comply with all other P2 requirements. Competitors must have copies of FIA Group CN Technical Regulations and V de V European Proto Endurance Series Challenge Sporting and Technical Regulations in their possession and present them upon request are available here: https://www.scca.com/pages/technical-forms-and-downloads."
GT1 Request to Classify Mazda 26B Engine
#36230 from Wayne Graham · Rule change · TB 24-09 (2024-09 Fastrack)
neutralGT1 Mazda 26B engine classified at 2850 lbs minimum weight.
In GT1 Spec Lines, GT1 Approved Automobile List, Mazda, add the following: "(Effective 11/1/2024) 26B engine = 2850 lbs."
GT1 Lamborghini Huracan GT3 Evo Restrictor Help
#36254 from Michael McAleenan · Rule change · TB 24-12 (2024-12 Fastrack)
fasterGT1-ST Lamborghini Huracan GT3 Evo and 2019+ GT3 both shift to Unrestricted from 39mm and 52mm restrictors.
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 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
Show 12 more lines
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"
GT1 Correct language regarding OEM Areo Devices
#37137 from Christopher Childs · Rule change · TB 25-01 (2025-01 Fastrack)
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.
GT1 GT1-ST Adjustments
#37481 from Grand Touring Committee · Rule change · TB 25-01 (2025-01 Fastrack)
unclearGT1-ST restrictor sizes removed for 13 cars; new specs not printed in letter.
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-):
Show 23 more lines
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"
P Correct text in engine table notes
#37606 from Club Racing Board · Rule change · TB 25-02 (2025-02 Fastrack)
neutralPrototype Staudacher and unrestricted engine notes corrected for minimum weight wording.
In Prototype Engine Table, Spec Line B, change the notes as follows: "Staudacher cars may run 950 lb min. wt. minimum weight with 38.5mm flat plate intake restrictor." In Prototype Engine Table, Spec Line D, change the notes as follows: "No restrictor required at 1150 lb min. wt. minimum weight."
P Update Prototype class designation
#37653 from Club Racing Board · Rule change · TB 25-02 (2025-02 Fastrack)
neutralPrototype class renamed from P1 to P, affecting designation throughout rules with no performance changes.
In Categories and Classes, GCR section 9.1, change as follows: "9.1.8. SPORTS RACING CATEGORY CLASSES A Sports Racing (ASR) Regional Class Prototype 1 (P1)" In Homologation Requirements, GCR section 9.2.2, change as follows: "All Formula, Sports Racing, and P1, and P2 cars must be constructed in strict accordance with the rules and regulations contained in the current GCR unless specifically excepted." In Non-Metallic Wheel/Chassis Construction, GCR section 9.3.37, change as follows:
Show 20 more lines
"Non-metallic wheel construction is prohibited. Non-metallic chassis construction is prohibited, except in ASR, P1, FS and FA." In Appendix B, GCR section 1.4.2.G, change as follows: "It is preferable not to combine GT1, AS, T1, T2, T3, and STU with P1, P2, SRF, FP, HP, or GTL." In Appendix C, GCR section 2.6.G, change as follows: "A 14 or 15 year-old must complete his first SCCA driver school in a car not classed in GT1, GT2, FA, FB, F S, ITR, ASR, P1, P2, or T1." In Appendix E, section 1, change as follows: "Depending on the length and banking of the oval course being used, it is recommended that Regions consider restricting the faster classes (GT1, FA, and P 1) from competition at oval track events." In Sports Racing Category, GCR section 9.1.8.1, change as follows: "The SCCA Sports Racing Category shall be for automobiles which are designed and constructed for road racing competition, offering provisions for a driver and passenger, or a driver alone (single-seater). They shall conform to the following requirements. Sports Racers Cars except SRF & SRF3 homologated prior to 1-1-2014 are eligible to compete as P1 or P2 as long as they meet applicable class rules,; no re-homologation is required." "Single seat Formula car chassis (Ex.: FA, FC, FF, FV) fitted with enclosed bodies (as specified in these rules) may run in a Sports Racing/Prototype Class (ASR, P 1, P2) provided they comply with the requirements of the Classification Specification and GCR Section 9." In Sports Racing Category, GCR section 9.1.8.2, change as follows: "In an effort to control shock/damper technology and cost to a level reasonable for Road Racing, in ASR, P1, and P2, any fluid dampers are allowed with the following restrictions:"
Cal Club 2025 → Cal Club 2026 2025-02-22 to 2026-02-21
neutralAcura NSX GT3 EVO 22 classified in GT1 with 3500cc twin turbo V-6, 3100 lbs, max RPM 7500.
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
Show 5 more lines
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.
FE2 Driver Safety & Comfort
#37965 from Robey Clark · Rule change · TB 25-04 (2025-04 Fastrack)
neutralFE2 allows driver safety and comfort modifications for disabled drivers with SCCA approval, not transferable to other drivers.
In FE2, GCR section 9.1.1.G.2.E, add the following: "g. 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."
P Add missing punctuation marks
#38150 from Club Racing Board · Rule change · TB 25-05 (2025-05 Fastrack)
neutralClass P adds clarification notes on restrictor requirements, throttle bodies, Mazda 12A engine spec, and P2 auto-based engine rules.
In P Engine Table, Spec Line D notes, add the following: "No restrictor required at 1150 lbs. minimum weight." In P Engine Table, Spec Line G notes, add the following: "Group CN non-composite chassis with Honda K20A-FD2 may use unrestricted individual throttle bodies at 1500 lbs. minimum weight." In P Table 1, Beasley B2 spec line notes, add the following: "Engine must be Mazda 12A rotary with 40.5mm venturi. Car must comply with all other Prototype requirements." In P Table 1, P2 cars built to 2000cc auto-based specification spec line notes, add the following:
Show 3 more lines
"Car must comply with all other P2 rules applicable to cars using stock production-based four-cylinder automotive engines. Note: Competitors are also free to modify their cars to comply with the general Prototype rules and Engine Table Spec Line H instead."
P RM 25-05 - Prototype Engine Table A, 2 Cycle Restrictor Change
#38929 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)
slowerPrototype Engine Table A 2-cycle restrictor reduces from 40mm to 38mm venturi size.
Effective 8/1/25 in Prototype Engine Table, Spec Line A, change the restrictor as follows: "40mm 38mm Restricted Venturi Size"
P 13B Rotary Engine Rules Change Request
#38856 from Jason Vinkemulder · Rule change · TB 25-09 (2025-09 Fastrack)
unclearP class 13B rotary engine restrictor changes to 40mm SIR fuel injection or 41.5mm venturi carburetor.
Effective 9/1/25 in Prototype Engine Table, Spec Line K, change the restrictor as follows: "40mm SIR with fuel injection or 41.5mm venturi with carburetor"
GT1 Correction to Limited prep LS Chevy engine for GT1
#38902 from Robert Logsdon · Rule change · TB 25-09 (2025-09 Fastrack)
neutralGT1 LS Limited Prep Engine expands to include LS1, LS2, LS3, LS6 with 11:1 max compression.
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."
P Add Radical Cup series Radical SR3 spec line to Table 1
#38916 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)
neutralPrototype class adds Radical SR3 spec line to Table 1 effective 9/1/25.
Effective 9/1/25 in Prototype Table 1 (Spec Line Cars), add the following:
P Clarify spec line cars language
#38943 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)
neutralPrototype P2 cars may now run P2 spec or modified Prototype spec in Prototype class; clarified language and added Radical Cup series table.
Effective 9/1/25, in Prototype, GCR section 9.1.8.B.K, change as follows: "P2 cars may compete in either the Prototype class or the P2 class but must participate in the Prototype class to the extent necessary to qualify for an invitation to the Runoffs in Prototype. P2 cars may be modified to comply with the general Prototype rules and Prototype Engine Table or may continue to run in P2 specification in the Prototype class as permitted in Table 1 below." Table 1 (Spec Line Cars)
A specification table follows in the original; it is not shown here.
FE2 FE & FE2 Bubble Tail
#38978 from Robey Clark · Rule change · TB 25-10 (2025-10 Fastrack)
neutralFE and FE2 Enterprises must use bubble tail P/N WM138014; FE2 allows only this configuration.
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."
GT1 RM 25-06 GT1 reclassify the Acura NSX GT3 EVO 22 to GT1-ST
#39101 from Club Racing Board · Rule change · TB 25-10 (2025-10 Fastrack)
neutralAcura NSX GT3 EVO 22 reclassified from GT1 to GT1-ST with 3100 lbs minimum weight.
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
Show 4 more lines
Displacement Minimum Weight Restrictor Notes ACURA NSX GT3 EVO 22 3500cc 3100 Per FIA Homologation GT3-047
GT1 NSX Parity With Other GT3s Let Alone a GT1 Car
neutralPrototype carbon-carbon and carbon-ceramic brake rotors now permitted instead of prohibited.
In Prototype, GCR section 9.1.8.B.F.2, change as follows: "Brake calipers may be ferrous or aluminum alloy. Effective 1/1/2026, carbon-carbon and carbon-ceramic brake rotors are prohibited and rotors must be ferrous. Brake rotor material is unrestricted."
GT1 Request for Addition of Porsche 992.1 GT3 Cup into GT1
#39322 from Erik Madsen · Rule change · TB 26-02 (2026-02 Fastrack)
neutralGT1 adds Porsche 992.1 GT3 Cup (2022-2025) with OEM ABS, traction control, RSR bumper, canards, and any exhaust allowed.
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."
What the rules allowed changed as listed; this does not say what any particular car ran.