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BoP Lab / Buttonwillow Raceway Park

FC vs GT1 vs SMX vs AS pace at Buttonwillow Raceway Park

Class · click a class to switch, + to compare alongside (up to 4: remove one to add another)
Reference class · the others' laps as a share of this one's at the same event, so years compare despite weather; + a class above to measure against it
Track configuration

Quickest here: FC 1:45.137 Robert Armington, Cal Club 2026 qualifying · GT1 1:39.857 Michael McAleenan, Cal Club 2026 qualifying · SMX 1:56.431 Ethan Lampe, Cal Club 2025 qualifying · AS 1:55.849 Roger Eagleton, Cal Club 2025 race

1:401:451:501:552:0022 rule changes between Cal Club 2025 and Cal Club 202622 ▾FC race best at Cal Club 2025: 1:48.522 (Paul MacFarlane)FC race best at Cal Club 2026: 1:45.314 (Robert Armington)FC qualifying best at Cal Club 2025: 1:50.067 (Paul MacFarlane)FC qualifying best at Cal Club 2026: 1:45.137 (Robert Armington)GT1 race best at Cal Club 2025: 1:42.305 (Michael Lewis)GT1 race best at Cal Club 2026: 1:41.045 (Michael McAleenan)GT1 qualifying best at Cal Club 2025: 1:43.967 (Michael Lewis)GT1 qualifying best at Cal Club 2026: 1:39.857 (Michael McAleenan)SMX race best at Cal Club 2025: 1:57.417 (Ethan Lampe)SMX race best at Cal Club 2026: 1:57.973 (William Wallis)SMX qualifying best at Cal Club 2025: 1:56.431 (Ethan Lampe)SMX qualifying best at Cal Club 2026: 1:56.503 (Lincoln Larson)AS race best at Cal Club 2025: 1:55.849 (Roger Eagleton)AS race best at Cal Club 2026: 1:56.314 (Ross Murray)AS qualifying best at Cal Club 2025: 1:56.445 (Roger Eagleton)AS qualifying best at Cal Club 2026: 1:56.812 (Ross Murray)Cal Club 20252025Cal Club 20262026
FCGT1SMXASsolid race · dashed qualifying · slower is lower
94%96%98%100%102%104%106%108%110%112%114%22 rule changes between Cal Club 2025 and Cal Club 202622 ▾FC race best at Cal Club 2025: 100.0% of FC's (Paul MacFarlane)FC race best at Cal Club 2026: 100.0% of FC's (Robert Armington)FC qualifying best at Cal Club 2025: 100.0% of FC's (Paul MacFarlane)FC qualifying best at Cal Club 2026: 100.0% of FC's (Robert Armington)GT1 race best at Cal Club 2025: 94.3% of FC's (Michael Lewis)GT1 race best at Cal Club 2026: 95.9% of FC's (Michael McAleenan)GT1 qualifying best at Cal Club 2025: 94.5% of FC's (Michael Lewis)GT1 qualifying best at Cal Club 2026: 95.0% of FC's (Michael McAleenan)SMX race best at Cal Club 2025: 108.2% of FC's (Ethan Lampe)SMX race best at Cal Club 2026: 112.0% of FC's (William Wallis)SMX qualifying best at Cal Club 2025: 105.8% of FC's (Ethan Lampe)SMX qualifying best at Cal Club 2026: 110.8% of FC's (Lincoln Larson)AS race best at Cal Club 2025: 106.8% of FC's (Roger Eagleton)AS race best at Cal Club 2026: 110.4% of FC's (Ross Murray)AS qualifying best at Cal Club 2025: 105.8% of FC's (Roger Eagleton)AS qualifying best at Cal Club 2026: 111.1% of FC's (Ross Murray)Cal Club 20252025Cal Club 20262026
FCGT1SMXASsolid race · dashed qualifying · each class's best lap as a share of FC's at the same event (the reference class, changeable above); 100% is level, higher is quicker
EventFCGT1SMXAS
Qual bestRace bestTrapQual bestRace bestTrapvs FC% of FCQual bestRace bestTrapvs FC% of FCQual bestRace bestTrapvs FC% of FC
Cal Club 2026 CALCL262026-02-211:45.137Robert Armington · fastest of 4 · top 4 within 25.0s-4.930s (-4.48%)1:45.314Robert Armington · fastest of 4 · top 4 within 12.9s-3.208s (-2.96%)147.5Bill Wallschlaeger+33.0 mph (+28.9%)1:39.857Michael McAleenan · fastest of 2-4.110s (-3.95%)1:41.045Michael McAleenan · fastest of 2-1.260s (-1.23%)167.6Michael McAleenan+53.8 mph (+47.3%)-4.269squal -5.280s95.9%qual 95.0%1:56.503Lincoln Larson · fastest of 15 · top 5 within 0.7s+0.072s (+0.06%)1:57.973William Wallis · fastest of 15 · top 5 within 0.8s+0.556s (+0.47%)141.6Joey Andrews+28.0 mph (+24.6%)+12.659squal +11.366s112.0%qual 110.8%1:56.812Ross Murray · fastest of 2+0.367s (+0.32%)1:56.314Ross Murray · fastest of 2+0.465s (+0.40%)135.2Ross Murray+26.5 mph (+24.4%)+11.000squal +11.675s110.4%qual 111.1%
22 rule changes (FC: 2, GT1: 5, SMX: 4, AS: 11)5 cars added · 4 weight · 2 induction · 11 wording · AS Chevy LS adds Edelbrock Performer RPM 71187 intake manifold with MSD 6014 ignition and 4776 Holly carburetor as spec line option. · GT1 adds Porsche 992.1 GT3 Cup (2022-2025) with OEM ABS, traction control, RSR bumper, canards, and any exhaust allowed. · AS Ford Mustang Restricted Prep engines lose 3 mm restrictor plate, from 64 mm to 61 mm. · FC USF2000 Tube Frame may use Hewland LD200 4-speed H-pattern as alternative to Hewland JL-200 5-speed sequential. · FC F2000 Metrik ZF2 minimum weight reduced to 1220 lbs. · GT1-ST Acura NSX GT3 EVO 22 weight drops 100 lbs to 3000 lbs. · AS Ford Mustang GT 94-04 Restricted Prep Engine now permits Ford Motorsport M-6250-F303 camshaft. · AS Cadillac CTS-V 04-07 Restricted Prep weight reduced 50 lbs to 3400. · Acura NSX GT3 EVO 22 reclassified from GT1 to GT1-ST with 3100 lbs minimum weight. · GT1 LS Limited Prep Engine expands to include LS1, LS2, LS3, LS6 with 11:1 max compression. · AS Ford Mustang GT 5.0 2018- weight reduced from 3600 to 3525 lbs. · AS Ford Mustang GT 05-14 Restricted Prep Engine gains alternative gear ratios: 3.66, 2.43, 1.69, 1.32, 1.00, .65 · SMX drivers must submit data acquisition files on time or face suspension and $250 fine. · SMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fine; level 2 and 4 may carry $500 fine. · AS Ford Mustang GT 5.0L (15-17) flat plate restrictor reduced from 67mm to 64mm. · AS LS1/LS6 5.3L truck engine gains four approved intake part numbers: 12561269, 88894095, 89017363, 89017364. · SMX Toyo RR P235/40/ZR17 tire rules clarified: one set per weekend, marking after first session, damage replacement procedures revised. · SMX data submission deadline extended from 30 to 60 minutes after each timed session. · AS Flotek Head plunge cut dimensions figure updated in GCR Section 9.1.6. · AS class notes cleanup: multiple Camaro, Firebird, CTS-V, Challenger, Mustang specs and fuel cell/ECM/head restrictions removed. · AS Spec Lines removes ECM flexibility restriction from five Cadillac and Chevrolet/Pontiac V8 models. · Acura NSX GT3 EVO 22 classified in GT1 with 3500cc twin turbo V-6, 3100 lbs, max RPM 7500.showhide
  • AS Edelbrock manifold (& timing kit) to Chevy LS Spec Lines Request #39055cars addedneutralAS Chevy LS adds Edelbrock Performer RPM 71187 intake manifold with MSD 6014 ignition and 4776 Holly carburetor as spec line option.
  • GT1 Request for Addition of Porsche 992.1 GT3 Cup into GT1 #39322cars addedneutralGT1 adds Porsche 992.1 GT3 Cup (2022-2025) with OEM ABS, traction control, RSR bumper, canards, and any exhaust allowed.
  • AS Restrictor Plate Change for Gen 2 Ford Coyote Engine #39501inductionslowerAS Ford Mustang Restricted Prep engines lose 3 mm restrictor plate, from 64 mm to 61 mm.
  • FC F2000 MZR Spec Line Clarity/Revision Requested #38927wordingneutralFC USF2000 Tube Frame may use Hewland LD200 4-speed H-pattern as alternative to Hewland JL-200 5-speed sequential.
  • FC Adjust F2000 Metrik ZF2 weight #39612weight -20 lbsfasterFC F2000 Metrik ZF2 minimum weight reduced to 1220 lbs.
  • GT1 NSX Parity With Other GT3s Let Alone a GT1 Car #39311weight -100 lbsfasterGT1-ST Acura NSX GT3 EVO 22 weight drops 100 lbs to 3000 lbs.
  • AS 1994 Mustang Spec Line Request #39104wordingunclearAS Ford Mustang GT 94-04 Restricted Prep Engine now permits Ford Motorsport M-6250-F303 camshaft.
  • AS Cadillac CTS-V BOP Weight Change #38640weight -50 lbsfasterAS Cadillac CTS-V 04-07 Restricted Prep weight reduced 50 lbs to 3400.
  • GT1 RM 25-06 GT1 reclassify the Acura NSX GT3 EVO 22 to GT1-ST #39101cars addedneutralAcura NSX GT3 EVO 22 reclassified from GT1 to GT1-ST with 3100 lbs minimum weight.
  • GT1 Correction to Limited prep LS Chevy engine for GT1 #38902cars addedneutralGT1 LS Limited Prep Engine expands to include LS1, LS2, LS3, LS6 with 11:1 max compression.
  • AS RE: Previous Letter 37695 Update #38245weight -75 lbsfasterAS Ford Mustang GT 5.0 2018- weight reduced from 3600 to 3525 lbs.
  • AS Errors and Omissions #38234wordingneutralAS Ford Mustang GT 05-14 Restricted Prep Engine gains alternative gear ratios: 3.66, 2.43, 1.69, 1.32, 1.00, .65
  • SMX SMX Data Submission - Penalties #38248wordingneutralSMX drivers must submit data acquisition files on time or face suspension and $250 fine.
  • SMX Committee) SMX Penaly Clarification updated language #38337wordingneutralSMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fine; level 2 and 4 may carry $500 fine.
  • AS Errors and Omission #38055inductionslowerAS Ford Mustang GT 5.0L (15-17) flat plate restrictor reduced from 67mm to 64mm.
  • AS Request to Add LS1/LS6 Intakes for 5.3L Truck Engine EnO #38197wordingneutralAS LS1/LS6 5.3L truck engine gains four approved intake part numbers: 12561269, 88894095, 89017363, 89017364.
  • SMX Clarify Tire Marking Regs #38004wordingneutralSMX Toyo RR P235/40/ZR17 tire rules clarified: one set per weekend, marking after first session, damage replacement procedures revised.
  • SMX SMX Data Submission Timeframe #38039wordingneutralSMX data submission deadline extended from 30 to 60 minutes after each timed session.
  • AS Flotek Head Plunge Cut Inconsistencies #37502wordingunclearAS Flotek Head plunge cut dimensions figure updated in GCR Section 9.1.6.
  • AS Notes clean up #37693wordingneutralAS class notes cleanup: multiple Camaro, Firebird, CTS-V, Challenger, Mustang specs and fuel cell/ECM/head restrictions removed.
  • AS Race memo #37902wordingunclearAS Spec Lines removes ECM flexibility restriction from five Cadillac and Chevrolet/Pontiac V8 models.
  • GT1 Request to Classify Acura NSX GT3 Evo 22 #37367cars addedneutralAcura NSX GT3 EVO 22 classified in GT1 with 3500cc twin turbo V-6, 3100 lbs, max RPM 7500.
Cal Club 2025 CALCL252025-02-221:50.067Paul MacFarlane · only car1:48.522Paul MacFarlane · only car114.4Paul MacFarlane1:43.967Michael Lewis · only car1:42.305Michael Lewis · only car113.8Michael Lewis-6.217squal -6.100s94.3%qual 94.5%1:56.431Ethan Lampe · fastest of 15 · top 5 within 1.5s1:57.417Ethan Lampe · fastest of 15 · top 5 within 1.6s113.6Ryan Gutile+8.895squal +6.364s108.2%qual 105.8%1:56.445Roger Eagleton · fastest of 3 · top 3 within 4.0s1:55.849Roger Eagleton · fastest of 4 · top 4 within 5.3s108.7Roger Eagleton+7.327squal +6.378s106.8%qual 105.8%
131 earlier rule changes on record, in force before Cal Club 2025 (from 2019)27 cars added · 21 weight · 10 engine · 8 tyres & wheels · 5 induction · 4 suspension & brakes · 2 aero · 52 wording · 2 other · AS Ford Mustang Coyote engines increase restrictor to 80mm from 64mm or 67mm. · AS Mustang GT 05-14 4.6L loses 300 lbs; 15-17 and 2018+ models lose 61mm and 60mm restrictors respectively. · AS class gear ratio options specified for multiple American muscle cars, including Cadillac CTS-V, Chevrolet Camaro, Ford Mustang, Dodge Challenger, and Pontiac GTO. · AS LS-engine cars gain ECU freedom; Camaro/Firebird 93-02 LS1 removes fuel cell location restriction. · GT1 LS1 Limited Prep engine added, 2600 lbs with driver, 383 cubic inches max, hydraulic roller cam, 750 cfm carb. · TA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof requirement. · GT1-ST restrictor sizes removed for 13 cars; new specs not printed in letter. · GT1-ST Lamborghini Huracan GT3 Evo and 2019+ GT3 both shift to Unrestricted from 39mm and 52mm restrictors. · SMX allows OE instrument cluster relocation for aftermarket dash mounting, with wiring re-routed only; alternate gauges now permitted. · FC tire limit reduced to four dry and four wet for Regional/Major/Super Tour, eight for Runoffs. · FF and FC cars with sequential gearbox must add 10 lbs. to minimum weight, down from 25 lbs. · GT1 Mazda 26B engine classified at 2850 lbs minimum weight. · AS Ford Mustang GT models gain alternate transmission ratio options for 2024-09-01. · SMX Spec MX-5 camera requirement wording changed; non-functioning recorder now grounds for penalty or disqualification. · SMX Spec MX-5 must run latest AIM Data Logger Spec MX-5 ECU Protocol; wording clarification for technical compliance. · SMX Mazda Miata OE versus OEM definitions clarified in GCR Section 9.1.7.1. · SM and SMX shifter bushing rules clarified: alternate bushing at shift lever bottom now allowed. · AS Ford Mustang GT 5.0L (2018-) classified at 3600 lbs with 60mm restrictor, Brembo BBK permitted. · AS Chevrolet Camaro 1LE (2016-) classified with 3600 lbs minimum weight, 60mm restrictor, 275 tires. · AS Chevrolet/Pontiac Camaro & Firebird 82-92 5.7L LS1 classified at 3200 lbs with 65mm restrictor plate required. · AS Chevrolet Camaro, Firebird, and Ford Mustang models permitted to use Flo Tek cylinder heads. · GT2-ST Acura NSX minimum weight raised to 3000 lbs, restrictor increased to 45mm TIR. · GT1 Camaro 1993-2002 classification updated; 2010- model separately classified. · AS Camaro/Firebird and GTO LS1 connecting rods approved: Callies CSC6100DS6A2AH, Scat 2-1CR6100-944, GM 12649190. · AS Cadillac CTS-V, Chevrolet Camaro SS, Dodge Challenger, Ford Mustang GT, Pontiac GTO allowed 11" wheels until 3/1/25. · FC adds F2000 Metrik ZF2 with Ford Zetec engine and four-piston Brembo calipers as spec-line car. · Chevrolet Camaro, Pontiac Firebird 70-81 Full Prep classified AS at 3400-3600 lbs with 250 lb weight reduction. · AS class: multiple cars gain fuel cell placement note allowing 24 inches from standard tank, unrestricted filler location. · Chevrolet Camaro 16- Full Prep classified into AS at 3400 lbs with 250 lb weight reduction. · AS adds Ford Mustang GT 05-14 Restricted prep Engine with 62mm FPR, 3400 lbs minimum, 18-inch wheels. · GT1, GT2, GT3, GTL, GTX rear spoiler maximum surface area limit of 295.0 square inches removed. · GT1/GT2/GT3/GTL/GTX Direct Injection now permitted if OE, using only OE pump, hoses, injectors. · GT2/3 Nissan, Mazda, Mitsubishi 4G93, QR25DE/DD, QE25DE/DD Direct Injection now permitted per 9.1.2.F.7.5.E. · F600 Rotax 494, 493, 593 engines now require single expansion chamber and pull starter; electric starter optional. · Lamborghini Huracan GT3 EVO(1) and GT3 added to GT1-ST at 3000 and 3100 lbs minimum weight respectively. · GT1 Trick Flow Specialties Ultra 18 Degree GM Cylinder Head Part #TFS-3181T001-CO1 allowed. · GTL spec lines moved to contiguous position with GT2 and GT3; GTA category and spec lines renumbered and moved behind GTL. · AS crate motor part number specified: GM Performance CT400 P/N 19370604 engine assembly for GM vehicles. · AS Spec Lines Ford Mustang GT 5.0L (15-17) max wheel size increases to 19.0 inches. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 now permits SPC-66045 alternate front upper control arms. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front brake caliper adapters for updated or backdated components. · FC tire marking rule clarified: four dry and wet tires for Regionals, eight each for Runoffs; damaged tire replacement procedures revised. · USF2000 Van Diemen with Mazda MZR LF-DE 2.0L added as spec line car in FC; removed from FX. · Fields Cardinal V8 classified in GT1 with Ford V8 engine, 4.9L displacement, 2100 lbs minimum weight. · GT1 Mercedes AMG GT3 16-19 preparation wording changed to per FIA GT3 homologation. · GT1 sequential transmission weight penalty reduced from 50 to 25 lbs. · GT1-ST Porsche 992 GT3 Cup classified with 3997cc displacement, 2950 lbs minimum weight. · FC/FF PE3-8400 ECU monitor firmware version reduced from V3.04.50 to V3.04.35. · GT2 TA2 and GTA throttle body part numbers updated to GM 90mm electronic #12570790 or Edelbrock 90mm mechanical #33869 or #3870. · GT1 Trans Am bodywork weight penalty reduced from 100 lbs to 75 lbs. · GT1 Chevrolet RO7, Ford FR9, and Dodge R7 weight penalties reduced from 50 to 25 lbs. · AS allows Hoosier W2 tyre option in addition to R7, R6, WET/H20. · AS Dodge Challenger 08-20 adds two transmission ratio options: 2.97, 2.10, 1.45, 1.00, 0.74, 0.50 or 2.26, 1.58, 1.19, 1.00, 0.77, 0.63. · GT taillights may now be original style or a panel graphic with functioning red LED brake lamps; wording change only. · GT1 TransAm bodywork allowed with 100 lb. weight penalty. · AS Cadillac CTS-V 6.0L V8 removes 50 lbs weight penalty for 295 tire size. · FC Ford Zetec Performance Electronics ECU model renamed PE-3 to PE3-8400; Monitor firmware updated to V3.04.50. · Mercedes Benz AMG GT3 classified in GT1 at 3050 lbs with 40mm restrictors, prepared per FIA GT3 homologation. · GT1 wheels: 18-inch tyres get wider rear allowance, from 13 to 14 MAX inches. · GT1 allows 17-inch wheels newly; 18-inch wheels require 50 lb penalty; maximum widths 12 front/13 rear, or 13/14 for 18-inch. · SMG long tube headers: Borla PN 17237 discontinued, Kooks PN 11312000 and American Racing PN MT3-05134300LSNC approved alternatives. · AS Mercury Capri (79-86) removed as individual spec line, merged into Ford Mustang (79-93) spec line. · AS Spec Mustang SMG loses 3.73 gear ratio and 355/300 mm brake specification. · AS Chevrolet, Pontiac, Ford full prep engines now permit alternate cylinder heads with restrictor plate ALL26180 and 1.250 inserts ALL26186 for regional competition. · FC chassis/frame section reorganized: anti-intrusion panels between main tubes clarified, suspension mounting restrictions strengthened, firewall requirements reworded. · FC Zetec ECU requirements clarified: Pectel T2 or Performance PE-3 required with specific communications ports and SCCA tune-file/map. · FC composite anti-intrusion panels of non-uniform thickness limited to eight fasteners per side. · FC tire marking rules clarified: competitor responsible for declaring, marking, and logging tires with Tech before qualifying or race. · AS Chevrolet/Pontiac Camaro & Firebird 93-02 now allow BMR AA004 or UMI 2310 adjustable front upper control arms. · AS Pontiac GTO 04-06 LS1 to 3300 lbs, LS2 to 3350 lbs on 295 tire. · GT3 Fun Cup Beetle EVO3 classified with 1984 cc sealed SOHC engine, 2060 lbs minimum weight. · GTA part numbers updated: 0-80541-1 to 0-80541-2 in two sections and 6010 to 6014X in TA2 Appendix. · AS Cadillac CTS-V 6.0L V8 removes 50 lbs tire size penalty, making it lighter. · AS consolidates seven SN95 Mustang spec lines into three: 94-04 including Cobra, 94-95 5.0/5.8, and 96-04 4.6L two/four valve. · AS Camaro/Firebird LT1/LS1 transmission code changes to 6362; Mustang GT 4.6L/5spd changes to 5.0L/6spd with 300 lbs weight reduction. · AS Camaro/Firebird and Mustang GT gear ratio specifications restored with alternate sets permitted. · AS Chevrolet Camaro & Firebird, Ford Mustang variants, Mercury Capri minimum weights increase 50 lbs across all model years. · AS Mustang 4.6L/5spd loses 300 lbs; 5.0L/6spd gains 56mm restrictor requirement. · AS CTS-V LS6 and LS2 may now use Driveshaft Shop carbon fiber driveshaft for durability. · AS Chevrolet Camaro SS V8 6.2L model years extended from 10-13 to 10-15. · FC Pinto engine loses 10 lbs to 1190; Pinto aluminum head loses 10 lbs to 1190; Zetec loses 10 lbs to 1210. · Ford Mustang GT 5.0L 15-17 Restricted Preparation classified in AS with 55mm flat plate restrictor required. · AS underhood bracing on stock hoods, trunks, and rear decks may be modified or removed. · AS Cadillac CTS-V 04-07 with 295 tire drops to 3450 lbs; Camaro SS V8 10-13 275 tire removed; Challenger 08-20 gains 315 tire option at 3600 lbs. · AS Camaro & Firebird (93-02) and Mustang GT (05-14) specifications restored with 200 lb weight reduction for permitted heads. · AS Dodge Challenger 08-20 gains 6.1L and 6.4L V8 options; 5.7L weight rises to 3500 lbs on 295 tyres, 3600 on 315 tyres. · AS Camaro/Firebird (93-02) and Mustang Coupe GT (05-14) consolidated into single specs with 100 lb and 300 lb weight reductions respectively. · FC: Pectel T2 and Performance PE-3 ECU maps clarified; SCCA Club or 2013 Pro map required. · GT1, GT2, GT3, GTL, GTX now permit turbocharging/supercharging if listed on spec line. · AS Dodge Challenger 5.7L V8 gets iron block requirement, 10.5:1 compression max, intake valve 12.7 mm, exhaust 12.3 mm, intake duration 188°, exhaust duration 205°. · AS Dodge Challenger 08-14 rear spoiler part number changes from 1GL20RXF to 1GL20TZZAB. · FC Zetec engine minimum weight increases 20 lbs to 1220 lbs. · GT1 adds Trans Am spec engines: Chevrolet R07, Ford FR9, Dodge R7, each with 50 lbs. weight penalty. · AS class pursues specified list of eligible tires; details of tire changes not provided in letter. · AS class pursuing specified list of eligible tires; details pending further communication. · No restrictor plate change implemented; 2021 AS Mustang Coyote under evaluation. · AS 2005-2009 Restricted Prep 4.6 3V now permits conversion to 2 valve configuration. · AS Ford Mustang Coupe GT 4.6L 3V Restricted Prep now permits Ford Performance camshaft kit P/N-M-6550-3V. · 2010-2014 Camaro reclassified to AS; full preparation classification approved effective 2020-07-01. · AS class cylinder head replacement options under review; implementation planned for 2021 season. · AS Mustang, Camaro, Firebird, Capri max brake rotor diameter increases from 12.2 to 13.1 inches. · AS rotor diameter increase approved; see Fastrack letter #28748 for details. · TA2 Gurney flap wording clarified: terminology standardized to 'Gurney flap', height limits and thickness specifications remain 0.50 inch / 0.625 inch or 0.375 inch / 0.0625 inch depending on configuration. · STO rear wing wording clarified: 'wicker' changed to 'Gurney flap' in maximum chord and mounting height rules. · GT1 Gurney flap wicker clarification: terminology standardized from lips/tabs/wicker to flaps throughout specifications. · GT classes clarify Gurney flap wording, replacing wickerbill/tab terminology with flap; specifications unchanged. · AS Chevrolet/Pontiac Camaro & Firebird (82-92) loses 50 lbs, to 3500. · AS rear trailing arms may be replaced with tubular arms maintaining stock length and axle location purpose only. · AS Ford and GM full-prep cars get 200 lb weight reduction, up from 150 lb. · 05-10 Ford Mustang Coupe GT 4.6L OHC classified AS with 3200 lbs minimum weight, HR cam restricted prep. · AS 10-15 Chevrolet Camaro Full Prep classified with 3400 lbs base weight, over 313 CID engine 3700 lbs maximum. · GT1, GT2, GT3, GTL, GTX may omit windshield clips if factory glass is bonded per original specifications. · GT2/ST Ford 5.0L Coyote 3rd Gen OEM added at 3200 lbs with Boss intake manifold permitted. · Factory Five Type 65 Coupe R with Ford 302/351 or 5.0/5.2L NA added to GTX-MISC at 2600 lbs. · GT1 sequential shifting transmission weight penalty reduced from 75 to 50 lbs. · GT1 non-18-inch-wheel cars now get 18-inch wheels with 50 lb penalty, down from 100 lb. · GT1 Spec Lines allows 5 Star NASCAR Camaro 2018+ body for General Motors Corporation. · FC Zetec connecting rods now allow Eagle #CRS5483F3D in addition to original Ford. · FC adds Mahle #930169439 piston as alternate option to existing Ford, Sealed Power, and United Engine choices. · AS Spec Mustang (SMG) added as Restricted Prep class. · GT1 Porsche 944/968 classified: 2981cc twin turbo, 2585 lbs minimum weight. · AS class minimum ride height clarified to 5 inches measured at rocker panel, excluding seams and cladding. · GT1 allows Trans Am rear wing, 12" chord, 72" span, 1/2" wicker, 100 sq in endplates, no weight penalty. · AS Ford Mustang (79-93) 313 CID and under loses 100 lbs to 3150; over 313 CID loses 100 lbs to 3450. · FC Wiseco piston and Crower connecting rod part numbers updated; minimum weight 976 grams. · GTX tube frame cars gain fuel injection with 90mm maximum throttle body size. · Ligier JS2 R classified in GTX, no performance parameters specified in filing. · GT1 and GT2/GT3/LITE ride height requirements removed from GCR sections 9.1.2.D.5.a.1 and 9.1.2.F.7.b. · AS Spec Mustang (SMG) newly classified with 107.1 wheelbase, 3.73 gears, 355mm front brakes, 300mm rear. · FC Wiseco piston and Crower connecting rod assembly minimum weight increases from 555 to 976 grams. · GTX FIA GT3: Audi R8 40mm restrictor 2900 lbs, BMW Z4 70mm 2800 lbs, Ferrari 488 35mm restrictor 3025 lbs classified.showhide
  • AS Increase Coyote Engine Restrictor to 80mm #36177inductionfasterAS Ford Mustang Coyote engines increase restrictor to 80mm from 64mm or 67mm.
  • AS Performance Pack for 2015+ Mustang #36867enginefasterAS Mustang GT 05-14 4.6L loses 300 lbs; 15-17 and 2018+ models lose 61mm and 60mm restrictors respectively.
  • AS Gear Ratios #37131wordingneutralAS class gear ratio options specified for multiple American muscle cars, including Cadillac CTS-V, Chevrolet Camaro, Ford Mustang, Dodge Challenger, and Pontiac GTO.
  • AS ECU specs for LS engine #37208enginefasterAS LS-engine cars gain ECU freedom; Camaro/Firebird 93-02 LS1 removes fuel cell location restriction.
  • GT1 Addition of a limited prep LS Chevy engine for GT1 #37045cars addedneutralGT1 LS1 Limited Prep engine added, 2600 lbs with driver, 383 cubic inches max, hydraulic roller cam, 750 cfm carb.
  • GT1 Correct language regarding OEM Areo Devices #37137wordingneutralTA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof requirement.
  • GT1 GT1-ST Adjustments #37481inductionunclearGT1-ST restrictor sizes removed for 13 cars; new specs not printed in letter.
  • GT1 Lamborghini Huracan GT3 Evo Restrictor Help #36254inductionfasterGT1-ST Lamborghini Huracan GT3 Evo and 2019+ GT3 both shift to Unrestricted from 39mm and 52mm restrictors.
  • SMX E&O SMX Regs 9.1.7.1.D.5.u-.w #37070wordingneutralSMX allows OE instrument cluster relocation for aftermarket dash mounting, with wiring re-routed only; alternate gauges now permitted.
  • FC 9.1.1.10.h. FC Tire Rule #36533tyres & wheelsslowerFC tire limit reduced to four dry and four wet for Regional/Major/Super Tour, eight for Runoffs.
  • FC Change FF/FC Weight with Sequential Gearbox #36651weightfasterFF and FC cars with sequential gearbox must add 10 lbs. to minimum weight, down from 25 lbs.
  • GT1 Request to Classify Mazda 26B Engine #36230cars addedneutralGT1 Mazda 26B engine classified at 2850 lbs minimum weight.
  • AS Mustang transmission ratios #36662wordingunclearAS Ford Mustang GT models gain alternate transmission ratio options for 2024-09-01.
  • SMX SMX Camera Rule Correction #36496wordingneutralSMX Spec MX-5 camera requirement wording changed; non-functioning recorder now grounds for penalty or disqualification.
  • SMX Committee) AIM ECU Protocol #36556wordingneutralSMX Spec MX-5 must run latest AIM Data Logger Spec MX-5 ECU Protocol; wording clarification for technical compliance.
  • SMX Committee) OE versus OEM Definitons #36608wordingneutralSMX Mazda Miata OE versus OEM definitions clarified in GCR Section 9.1.7.1.
  • SMX Committee) Shifter Bushing #36611wordingneutralSM and SMX shifter bushing rules clarified: alternate bushing at shift lever bottom now allowed.
  • AS Request for Classification of 2018-2023 mustang In #35764cars addedneutralAS Ford Mustang GT 5.0L (2018-) classified at 3600 lbs with 60mm restrictor, Brembo BBK permitted.
  • AS 6th gen Camaro limited prep #35733cars addedneutralAS Chevrolet Camaro 1LE (2016-) classified with 3600 lbs minimum weight, 60mm restrictor, 275 tires.
  • AS Chevrolet/Pontiac Camaro & Firebird (82-92) 5.7L V8 LS1 Alum BLK #35825cars addedneutralAS Chevrolet/Pontiac Camaro & Firebird 82-92 5.7L LS1 classified at 3200 lbs with 65mm restrictor plate required.
  • AS Full Prep Head #35891otherneutralAS Chevrolet Camaro, Firebird, and Ford Mustang models permitted to use Flo Tek cylinder heads.
  • GT1 Request for Spec Line 1010 Reconsideration #35009weight +300 lbsslowerGT2-ST Acura NSX minimum weight raised to 3000 lbs, restrictor increased to 45mm TIR.
  • GT1 Camaro 1993- and 2010- #35652wordingneutralGT1 Camaro 1993-2002 classification updated; 2010- model separately classified.
  • AS Restricted Prep Aftermarket Parts Request #35682wordingneutralAS Camaro/Firebird and GTO LS1 connecting rods approved: Callies CSC6100DS6A2AH, Scat 2-1CR6100-944, GM 12649190.
  • AS Allowance of 11 #35824tyres & wheelsfasterAS Cadillac CTS-V, Chevrolet Camaro SS, Dodge Challenger, Ford Mustang GT, Pontiac GTO allowed 11" wheels until 3/1/25.
  • FC Four Pot Calipers #35481cars addedneutralFC adds F2000 Metrik ZF2 with Ford Zetec engine and four-piston Brembo calipers as spec-line car.
  • AS Request to Classify 1970-1981 Camaro and Firebird in AS #33659cars addedneutralChevrolet Camaro, Pontiac Firebird 70-81 Full Prep classified AS at 3400-3600 lbs with 250 lb weight reduction.
  • AS Fuel Cell 12 #34194wordingneutralAS class: multiple cars gain fuel cell placement note allowing 24 inches from standard tank, unrestricted filler location.
  • AS Please Classify the 6th Gen Into AS. #35448cars addedneutralChevrolet Camaro 16- Full Prep classified into AS at 3400 lbs with 250 lb weight reduction.
  • AS spec lines #35713cars addedneutralAS adds Ford Mustang GT 05-14 Restricted prep Engine with 62mm FPR, 3400 lbs minimum, 18-inch wheels.
  • GT1 Rear Blade Spoiler Clarification #35261aerofasterGT1, GT2, GT3, GTL, GTX rear spoiler maximum surface area limit of 295.0 square inches removed.
  • GT1 GT Direct Injection allowance and rules #35437enginefasterGT1/GT2/GT3/GTL/GTX Direct Injection now permitted if OE, using only OE pump, hoses, injectors.
  • GT1 GT2/3 remove Direction Injection not allowed in Spec line notes #35439inductionfasterGT2/3 Nissan, Mazda, Mitsubishi 4G93, QR25DE/DD, QE25DE/DD Direct Injection now permitted per 9.1.2.F.7.5.E.
  • FC Please correct omitted punctuation #34890engineneutralF600 Rotax 494, 493, 593 engines now require single expansion chamber and pull starter; electric starter optional.
  • GT1 Request for Acceptance of Lamborghini Huracan GT3 in GT1-ST #34929cars addedneutralLamborghini Huracan GT3 EVO(1) and GT3 added to GT1-ST at 3000 and 3100 lbs minimum weight respectively.
  • GT1 Cylinder heads #35040wordingneutralGT1 Trick Flow Specialties Ultra 18 Degree GM Cylinder Head Part #TFS-3181T001-CO1 allowed.
  • GT1 Errors in GTCS Headings and Use of the Terms Category and ClassChange existing GTL and GTA Rules #34453wordingneutralGTL spec lines moved to contiguous position with GT2 and GT3; GTA category and spec lines renumbered and moved behind GTL.
  • AS Crate Motor Part Numbers #32944wordingneutralAS crate motor part number specified: GM Performance CT400 P/N 19370604 engine assembly for GM vehicles.
  • AS Request wheel size change #33007tyres & wheelsfasterAS Spec Lines Ford Mustang GT 5.0L (15-17) max wheel size increases to 19.0 inches.
  • AS Alternative Upper Front Control Arms for Dodge Challenger #33352wordingneutralAS Dodge Challenger 5.7L/6.1L/6.4L V8 now permits SPC-66045 alternate front upper control arms.
  • AS Front Brake Caliper Adapters for Dodge Challenger #33353wordingneutralAS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front brake caliper adapters for updated or backdated components.
  • FC Review FC Runoffs Tire Marking Rule #34274wordingneutralFC tire marking rule clarified: four dry and wet tires for Regionals, eight each for Runoffs; damaged tire replacement procedures revised.
  • FC USF2000 Van Diemen with Mazda MZR LF-DE 2.0L in FC #34329cars addedneutralUSF2000 Van Diemen with Mazda MZR LF-DE 2.0L added as spec line car in FC; removed from FX.
  • GT1 Please classify Fields Cardinal V8 #33784cars addedneutralFields Cardinal V8 classified in GT1 with Ford V8 engine, 4.9L displacement, 2100 lbs minimum weight.
  • GT1 Mercedes AMG GT3 Notes #33804wordingneutralGT1 Mercedes AMG GT3 16-19 preparation wording changed to per FIA GT3 homologation.
  • GT1 Sequential Transmission Weight Penalty #33503weightfasterGT1 sequential transmission weight penalty reduced from 50 to 25 lbs.
  • GT1 GT1 Porsche 992 #33730cars addedneutralGT1-ST Porsche 992 GT3 Cup classified with 3997cc displacement, 2950 lbs minimum weight.
  • FC E&O 9.1.1.B.16.j #33634wordingunclearFC/FF PE3-8400 ECU monitor firmware version reduced from V3.04.50 to V3.04.35.
  • GT1 GT2 (TA2)/GTA Part Number Update #33315wordingneutralGT2 TA2 and GTA throttle body part numbers updated to GM 90mm electronic #12570790 or Edelbrock 90mm mechanical #33869 or #3870.
  • GT1 Request to Reduce Trans Am Bodywork Weight Penalty #33331weightfasterGT1 Trans Am bodywork weight penalty reduced from 100 lbs to 75 lbs.
  • GT1 Request for Reduction in FR9 Weight Penalty #33332weightfasterGT1 Chevrolet RO7, Ford FR9, and Dodge R7 weight penalties reduced from 50 to 25 lbs.
  • AS Request to add Hoosier W2 #33031tyres & wheelsneutralAS allows Hoosier W2 tyre option in addition to R7, R6, WET/H20.
  • AS correction of Dodge Challenger specification line #33151wordingneutralAS Dodge Challenger 08-20 adds two transmission ratio options: 2.97, 2.10, 1.45, 1.00, 0.74, 0.50 or 2.26, 1.58, 1.19, 1.00, 0.77, 0.63.
  • GT1 Tail lights on all GT category race cars. #32799wordingneutralGT taillights may now be original style or a panel graphic with functioning red LED brake lamps; wording change only.
  • GT1 GT-1/TransAm rules simplification/modernizing #32763weightslowerGT1 TransAm bodywork allowed with 100 lb. weight penalty.
  • AS Request CTS-V Spec Line Error Correction #30242weightfasterAS Cadillac CTS-V 6.0L V8 removes 50 lbs weight penalty for 295 tire size.
  • FC Add Specification to Performance Electronics ECU for Ford Zetec #32761wordingneutralFC Ford Zetec Performance Electronics ECU model renamed PE-3 to PE3-8400; Monitor firmware updated to V3.04.50.
  • GT1 Mercedes Benz AMG GT3 in GT1 #31883cars addedneutralMercedes Benz AMG GT3 classified in GT1 at 3050 lbs with 40mm restrictors, prepared per FIA GT3 homologation.
  • GT1 Wheel Widths #32205tyres & wheelsfasterGT1 wheels: 18-inch tyres get wider rear allowance, from 13 to 14 MAX inches.
  • GT1 Wheel Widths #31844tyres & wheelsslowerGT1 allows 17-inch wheels newly; 18-inch wheels require 50 lb penalty; maximum widths 12 front/13 rear, or 13/14 for 18-inch.
  • AS Proposed Revisions to SCCA GCR 2021 Appendix M, Part 3 #30295wordingneutralSMG long tube headers: Borla PN 17237 discontinued, Kooks PN 11312000 and American Racing PN MT3-05134300LSNC approved alternatives.
  • AS specification line consolidation and correction #31846wordingneutralAS Mercury Capri (79-86) removed as individual spec line, merged into Ford Mustang (79-93) spec line.
  • AS correction of SMG specification line #31847wordingunclearAS Spec Mustang SMG loses 3.73 gear ratio and 355/300 mm brake specification.
  • AS Alternate cylinder heads for full prep engine builds - Evaluation #31851engineunclearAS Chevrolet, Pontiac, Ford full prep engines now permit alternate cylinder heads with restrictor plate ALL26180 and 1.250 inserts ALL26186 for regional competition.
  • FC Clean up Chassis/Frame section #31867wordingneutralFC chassis/frame section reorganized: anti-intrusion panels between main tubes clarified, suspension mounting restrictions strengthened, firewall requirements reworded.
  • FC Clarify Zetec ECU requirements #31554wordingneutralFC Zetec ECU requirements clarified: Pectel T2 or Performance PE-3 required with specific communications ports and SCCA tune-file/map.
  • FC Clarify composite anti-intrusion panel language #31426wordingneutralFC composite anti-intrusion panels of non-uniform thickness limited to eight fasteners per side.
  • FC Clarify tire marking requirements #31455wordingneutralFC tire marking rules clarified: competitor responsible for declaring, marking, and logging tires with Tech before qualifying or race.
  • AS Request for adjustable Front Upper Control Arms on 4th Gen F-Body #30457suspension & brakesneutralAS Chevrolet/Pontiac Camaro & Firebird 93-02 now allow BMR AA004 or UMI 2310 adjustable front upper control arms.
  • AS Request Pontiac GTO tire size change #30881weightslowerAS Pontiac GTO 04-06 LS1 to 3300 lbs, LS2 to 3350 lbs on 295 tire.
  • GT1 Request car classification #31032cars addedneutralGT3 Fun Cup Beetle EVO3 classified with 1984 cc sealed SOHC engine, 2060 lbs minimum weight.
  • GT1 Request to Update GTA Obsolete Part Numbers #30615wordingneutralGTA part numbers updated: 0-80541-1 to 0-80541-2 in two sections and 6010 to 6014X in TA2 Appendix.
  • AS Request CTS-V Spec Line Error Correction #30242weightfasterAS Cadillac CTS-V 6.0L V8 removes 50 lbs tire size penalty, making it lighter.
  • AS Request to consolidate SN95 Mustang '94-'04 Mustang spec lines #30428wordingneutralAS consolidates seven SN95 Mustang spec lines into three: 94-04 including Cobra, 94-95 5.0/5.8, and 96-04 4.6L two/four valve.
  • AS American Sedan Transmission Rule Change Request #30595enginefasterAS Camaro/Firebird LT1/LS1 transmission code changes to 6362; Mustang GT 4.6L/5spd changes to 5.0L/6spd with 300 lbs weight reduction.
  • AS Correction to specifications inadvertently deleted #30691wordingneutralAS Camaro/Firebird and Mustang GT gear ratio specifications restored with alternate sets permitted.
  • AS weight adjustments #30700weight +50 lbsslowerAS Chevrolet Camaro & Firebird, Ford Mustang variants, Mercury Capri minimum weights increase 50 lbs across all model years.
  • AS AS Mustang LP 4.6 3V Classification Transmission Request #29886weightfasterAS Mustang 4.6L/5spd loses 300 lbs; 5.0L/6spd gains 56mm restrictor requirement.
  • AS Request CF driveshaft on CTS-V for durability improvement #30117otherneutralAS CTS-V LS6 and LS2 may now use Driveshaft Shop carbon fiber driveshaft for durability.
  • AS Adjustment to model years of 5th generation RP Camaro #30348wordingneutralAS Chevrolet Camaro SS V8 6.2L model years extended from 10-13 to 10-15.
  • FC Request for FC Weight Change #30171weightfasterFC Pinto engine loses 10 lbs to 1190; Pinto aluminum head loses 10 lbs to 1190; Zetec loses 10 lbs to 1210.
  • AS Request for 2015 -2017 Ford Mustang Spec Line #29514cars addedneutralFord Mustang GT 5.0L 15-17 Restricted Preparation classified in AS with 55mm flat plate restrictor required.
  • AS Request Trunk lid / Rear Hatch clarification #29591wordingneutralAS underhood bracing on stock hoods, trunks, and rear decks may be modified or removed.
  • AS Common Weight for CTS-V Tire #29759weightfasterAS Cadillac CTS-V 04-07 with 295 tire drops to 3450 lbs; Camaro SS V8 10-13 275 tire removed; Challenger 08-20 gains 315 tire option at 3600 lbs.
  • AS Correction to specifications inadvertently deleted #30041weightfasterAS Camaro & Firebird (93-02) and Mustang GT (05-14) specifications restored with 200 lb weight reduction for permitted heads.
  • AS Request Additional Engine Options for Dodge Challenger Spec Line #29543engineslowerAS Dodge Challenger 08-20 gains 6.1L and 6.4L V8 options; 5.7L weight rises to 3500 lbs on 295 tyres, 3600 on 315 tyres.
  • AS Rule simplification spec line communization #29824wordingfasterAS Camaro/Firebird (93-02) and Mustang Coupe GT (05-14) consolidated into single specs with 100 lb and 300 lb weight reductions respectively.
  • FC Urgent: SCCA PE3 map unsuitable #29475wordingneutralFC: Pectel T2 and Performance PE-3 ECU maps clarified; SCCA Club or 2013 Pro map required.
  • GT1 GT Category Wording #29193wordingunclearGT1, GT2, GT3, GTL, GTX now permit turbocharging/supercharging if listed on spec line.
  • AS Dodge Challenger AS Spec Line Clarification #28698engineslowerAS Dodge Challenger 5.7L V8 gets iron block requirement, 10.5:1 compression max, intake valve 12.7 mm, exhaust 12.3 mm, intake duration 188°, exhaust duration 205°.
  • AS Dodge Challenger AS Spec Line Clarification #2 #28699wordingneutralAS Dodge Challenger 08-14 rear spoiler part number changes from 1GL20RXF to 1GL20TZZAB.
  • FC Request for weight adjustments to equalize FC competition. #28888weightslowerFC Zetec engine minimum weight increases 20 lbs to 1220 lbs.
  • GT1 Request to Allow New Trans Am Legal Engines in GT1 #29002engineslowerGT1 adds Trans Am spec engines: Chevrolet R07, Ford FR9, Dodge R7, each with 50 lbs. weight penalty.
  • AS Support for R-Type Specification Tires #27450tyres & wheelsunclearAS class pursues specified list of eligible tires; details of tire changes not provided in letter.
  • AS Spec Tire Request #27519tyres & wheelsunclearAS class pursuing specified list of eligible tires; details pending further communication.
  • AS Restrictor Plate Change for RP 2011+ Mustang with Coyote Engine #27675wordingunclearNo restrictor plate change implemented; 2021 AS Mustang Coyote under evaluation.
  • AS 2005-2009 Restricted Prep 4.6 3V #27908engineunclearAS 2005-2009 Restricted Prep 4.6 3V now permits conversion to 2 valve configuration.
  • AS Request for 2005-2009 Restricted Prep 4.6 3V Parts #27909wordingunclearAS Ford Mustang Coupe GT 4.6L 3V Restricted Prep now permits Ford Performance camshaft kit P/N-M-6550-3V.
  • AS Request for Full Preparation Classification for 2010-2014 Camaro #28030cars addedunclear2010-2014 Camaro reclassified to AS; full preparation classification approved effective 2020-07-01.
  • AS Cylinder Heads #28696wordingunclearAS class cylinder head replacement options under review; implementation planned for 2021 season.
  • AS Request for Max Rotor Diameter Change #28748suspension & brakesfasterAS Mustang, Camaro, Firebird, Capri max brake rotor diameter increases from 12.2 to 13.1 inches.
  • AS Request increase rotor diameter #28797suspension & brakesneutralAS rotor diameter increase approved; see Fastrack letter #28748 for details.
  • GT1 TA2 Gurney flap wicker clarification #28874wordingneutralTA2 Gurney flap wording clarified: terminology standardized to 'Gurney flap', height limits and thickness specifications remain 0.50 inch / 0.625 inch or 0.375 inch / 0.0625 inch depending on configuration.
  • GT1 STO Gurney flap wicker clarification #28883wordingneutralSTO rear wing wording clarified: 'wicker' changed to 'Gurney flap' in maximum chord and mounting height rules.
  • GT1 GT1 Gurney flap wicker clarification #28886wordingneutralGT1 Gurney flap wicker clarification: terminology standardized from lips/tabs/wicker to flaps throughout specifications.
  • GT1 GT Gurney flap wicker clarification #28909wordingneutralGT classes clarify Gurney flap wording, replacing wickerbill/tab terminology with flap; specifications unchanged.
  • AS weight adjustments for 2020 season #28785weight -50 lbsfasterAS Chevrolet/Pontiac Camaro & Firebird (82-92) loses 50 lbs, to 3500.
  • AS Rear Trailing Arms #28007suspension & brakesneutralAS rear trailing arms may be replaced with tubular arms maintaining stock length and axle location purpose only.
  • AS Weight reduction for cars running iron heads #28010weightfasterAS Ford and GM full-prep cars get 200 lb weight reduction, up from 150 lb.
  • AS 05-10 Mustang with HR cam classification #28226cars addedneutral05-10 Ford Mustang Coupe GT 4.6L OHC classified AS with 3200 lbs minimum weight, HR cam restricted prep.
  • AS 10-15 Camaro Full Prep classification #28227cars addedneutralAS 10-15 Chevrolet Camaro Full Prep classified with 3400 lbs base weight, over 313 CID engine 3700 lbs maximum.
  • GT1 Windshield Clips #27323wordingneutralGT1, GT2, GT3, GTL, GTX may omit windshield clips if factory glass is bonded per original specifications.
  • GT1 Request to classify the Ford Coyote 3rd Gen OEM #27146cars addedneutralGT2/ST Ford 5.0L Coyote 3rd Gen OEM added at 3200 lbs with Boss intake manifold permitted.
  • GT1 Request Factory Five Daytona coupe classification #26308cars addedneutralFactory Five Type 65 Coupe R with Ford 302/351 or 5.0/5.2L NA added to GTX-MISC at 2600 lbs.
  • GT1 Request to Adjust Transmission Penalty #27750weightfasterGT1 sequential shifting transmission weight penalty reduced from 75 to 50 lbs.
  • GT1 Request to Reduce Additional Weight for 18 #27751weightfasterGT1 non-18-inch-wheel cars now get 18-inch wheels with 50 lb penalty, down from 100 lb.
  • GT1 Request for Five Star Nascar Compliant Bodywork #27756cars addedneutralGT1 Spec Lines allows 5 Star NASCAR Camaro 2018+ body for General Motors Corporation.
  • FC Request for Better Zetec Connecting Rods #27710wordingneutralFC Zetec connecting rods now allow Eagle #CRS5483F3D in addition to original Ford.
  • FC Add Alternate Piston #27795wordingneutralFC adds Mahle #930169439 piston as alternate option to existing Ford, Sealed Power, and United Engine choices.
  • AS Request to add SMG to 9.1.6.B.1 AS Intent #27140cars addedneutralAS Spec Mustang (SMG) added as Restricted Prep class.
  • GT1 Request to classify Porsche 944/968 #26242cars addedneutralGT1 Porsche 944/968 classified: 2981cc twin turbo, 2585 lbs minimum weight.
  • AS Request Ride Height Clarification #26598wordingneutralAS class minimum ride height clarified to 5 inches measured at rocker panel, excluding seams and cladding.
  • GT1 Clarify Trans Am Legal Bodywork and Wing #26953aerofasterGT1 allows Trans Am rear wing, 12" chord, 72" span, 1/2" wicker, 100 sq in endplates, no weight penalty.
  • AS Request to Revert to 2017 Weights #25885weightfasterAS Ford Mustang (79-93) 313 CID and under loses 100 lbs to 3150; over 313 CID loses 100 lbs to 3450.
  • FC E&O Wiseco piston and Crower connecting rod #26659wordingneutralFC Wiseco piston and Crower connecting rod part numbers updated; minimum weight 976 grams.
  • GT1 Request GTX Fuel injection for previous GT-1 tube frame cars #26141inductionfasterGTX tube frame cars gain fuel injection with 90mm maximum throttle body size.
  • GT1 Request to Classify Ligier JS2 R #26535cars addedneutralLigier JS2 R classified in GTX, no performance parameters specified in filing.
  • GT1 Request Ride Height Clarification #26600wordingneutralGT1 and GT2/GT3/LITE ride height requirements removed from GCR sections 9.1.2.D.5.a.1 and 9.1.2.F.7.b.
  • AS SMG Mustang eligibility in American sedan #26224cars addedneutralAS Spec Mustang (SMG) newly classified with 107.1 wheelbase, 3.73 gears, 355mm front brakes, 300mm rear.
  • FC Correct Wiseco piston and connecting rod #25809weightslowerFC Wiseco piston and Crower connecting rod assembly minimum weight increases from 555 to 976 grams.
  • GT1 GTX Homologation table update #26034cars addedneutralGTX FIA GT3: Audi R8 40mm restrictor 2900 lbs, BMW Z4 70mm 2800 lbs, Ferrari 488 35mm restrictor 3025 lbs classified.

Best is the class's fastest lap in that event's qualifying or race sessions, with the driver who set it, how many cars set a time that session and how close the top five were; a best from fewer than three cars is greyed. With two or more classes, "vs" is the gap of each class's best to the first class's at the same event. "% of FC" is the class's best as a share of FC's best at the same event (100% is level, less is quicker): weather and track condition move every class together, so this compares across years where the raw times do not. It still breaks when FC's own field changes or one session was wet and another dry. Newest event first. The coloured figure under each value is the change from the previous event that has one (green is quicker, red slower). Whole laps only, so events with different sector layouts still compare. Weather and track condition are not accounted for.