Quickest here:STL 1:54.845 Gavin Wardle, Cal Club 2026 race · P2 1:37.278 Tim Day Jr, Cal Club 2026 qualifying · FA 1:35.792 Greg Labadie, Cal Club 2026 qualifying
STLP2FAsolid race · dashed qualifying · slower is lower
STLP2FAsolid race · dashed qualifying · each class's best lap as a share of STL's at the same event (the reference class, changeable above); 100% is level, higher is quicker
Event
STL
P2
FA
Qual best
Race best
Trap
Qual best
Race best
Trap
vs STL
% of STL
Qual best
Race best
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% of STL
Cal Club 2026 CALCL262026-02-21
1:57.526Jared Korth · fastest of 10 · top 5 within 1.2s+2.563s (+2.23%)
1:54.845Gavin Wardle · fastest of 11 · top 5 within 4.7s-0.837s (-0.72%)
136.6Bryce Johnson+26.2 mph (+23.7%)
1:37.278Tim Day Jr · only car
1:39.758Tim Day Jr · only car
155.4Tim Day Jr
-15.087squal -20.248s
86.9%qual 82.8%
1:35.792Greg Labadie · only car-3.750s (-3.77%)
1:37.275Greg Labadie · only car-2.623s (-2.63%)
163.8Greg Labadie+36.4 mph (+28.6%)
-17.570squal -21.734s
84.7%qual 81.5%
10 rule changes (STL: 3, FA: 7)2 induction · 2 weight · 1 aero · 1 cars added · 1 engine · 1 tyres & wheels · 2 wording · FA Pro Mazda: lower intake manifold now unrestricted, throttle body raised to 80mm, wing height must not exceed 99cm, bodywork width must not exceed 132cm. · FA MZR gains alternate Noor P/N 0088-8-00 intake manifold with AT Power runners as option to Elan or Mazda Speed Elite. · FA Formula 1000 motorcycle-based engine loses maximum compression ratio 14.5:1 limit. · FA Formula 1000 allows carbon fiber external panels, forward-facing gaps, raises floor to 125mm, adds eight 75×125mm rub blocks, expands diffuser to 110cm with 75mm radius transitions. · STL minimum weights increase across all classes, 1300 cc gains 195 lbs to 1950, up to 1850 cc at 2500. · FA class adds USF Pro 2000 car eligibility for Formula Atlantic racing. · STL/STU Lotus weight reduced: Evora GT4 to 2700 lbs, Elise Cup R to 2250 lbs, Elise/Exige SC to 2450-2550 lbs. · FA Ligier JS F3 front tires may be Hoosier 43363 240/580R13 MS, rear 43368 300/590R13 MS. · STL Mazda MX5 Challenge minimum weight now references GCR 9.1.7.1 instead of 2500 lbs; spec components removed, only alternative tires allowed. · FA Formula Renault 2.0 (10-17) spec notes clarified: engine sealed, manual compliance required, tire choice unrestricted, no alterations except repairs.showhide
FA Pro Mazda Classification and Performance Enhancement Proposal #39411inductionfasterFA Pro Mazda: lower intake manifold now unrestricted, throttle body raised to 80mm, wing height must not exceed 99cm, bodywork width must not exceed 132cm.
FA Alternate Intake Manifold for MZR #38223inductionunclearFA MZR gains alternate Noor P/N 0088-8-00 intake manifold with AT Power runners as option to Elan or Mazda Speed Elite.
FA Engine Compression Rule Change Request #39302enginefasterFA Formula 1000 motorcycle-based engine loses maximum compression ratio 14.5:1 limit.
FA Change Formula 1000 allowances #39608aerofasterFA Formula 1000 allows carbon fiber external panels, forward-facing gaps, raises floor to 125mm, adds eight 75×125mm rub blocks, expands diffuser to 110cm with 75mm radius transitions.
STL Weight adjustment for STL #39579weightslowerSTL minimum weights increase across all classes, 1300 cc gains 195 lbs to 1950, up to 1850 cc at 2500.
FA Re-Consider USF Pro 2000 Car for Formula Atlantic Class #38783cars addedneutralFA class adds USF Pro 2000 car eligibility for Formula Atlantic racing.
STL Lotus Weight Reduction #38772weight -50 lbsfasterSTL/STU Lotus weight reduced: Evora GT4 to 2700 lbs, Elise Cup R to 2250 lbs, Elise/Exige SC to 2450-2550 lbs.
FA Ligier JS F3 Tire Choice #38434tyres & wheelsneutralFA Ligier JS F3 front tires may be Hoosier 43363 240/580R13 MS, rear 43368 300/590R13 MS.
STL E&O: SMX Allowance in STL #37945wordingunclearSTL Mazda MX5 Challenge minimum weight now references GCR 9.1.7.1 instead of 2500 lbs; spec components removed, only alternative tires allowed.
FA Update Formula Renault 2.0 spec line notes #37853wordingneutralFA Formula Renault 2.0 (10-17) spec notes clarified: engine sealed, manual compliance required, tire choice unrestricted, no alterations except repairs.
Cal Club 2025 CALCL252025-02-22
1:54.963Nick Leverone · fastest of 16 · top 5 within 3.3s
1:55.682Nick Leverone · fastest of 17 · top 5 within 2.6s
110.4Ryan Gutile
1:39.542Greg Labadie · only car
1:39.898Greg Labadie · only car
127.4Greg Labadie
-15.784squal -15.421s
86.4%qual 86.6%
155 earlier rule changes on record, in force before Cal Club 2025 (from 2019)24 induction · 19 cars added · 14 engine · 10 weight · 6 aero · 2 tyres & wheels · 1 removed · 78 wording · 1 other · FA adds Tatuus F.3 T-318 or FR-19 as spec line car in Table 2 for Formula Regional European Championship. · P2 2000cc Pinto engine car minimum weight set to 1335 lbs. · STL/STU: 90-05 Mazda Miata alternate front wheel hubs moved from General to specific part approval. · P2 Spec ECU engine modifications clarified: oil system, ECU, and exhaust unrestricted only. · P2 FIA Group CN spec notes clarified: Series changed to Challenge, documentation requirement moved to online link. · STL and STU power steering rules clarified to permit electric-assisted and hydraulic-assisted steering systems. · STL Acura/Honda B-series and Mazda MZR restrictors reduced 2mm; minimum weights down 25–75 lbs for 1900–2000cc engines. · STL Mazda 12A must keep 5th and 6th intake port actuators and valves, no longer allowed removal or disabling. · P2 AMAC modified engine range clarified to 2008 and older stock engines only, restrictor 38mm, weight 1025 lbs. · P2 Suzuki GSX-R1000 07/08 engine crankcase may swap to GSX-S1000 16/19 part #11301-04840. · STL Mazda RX-7 12A (79-85) now allows auto-type 2 bbl with 42mm choke(s) on dual-y manifold as alternate to stock Nikki 4 bbl. · P2 Table 1 corrects engine date ranges and brand specifications for Stock and Modified engines across multiple car models. · FA Pro Formula Mazda front wheels widen to 10 in. max; rear wheels narrow to 14 in. min. · STL ITA/ITS RX7 and 1985+ ITA/ITS/ITB/ITC vehicles clarified to conform to section 9.1.4.2 tire specifications. · FA Pro Formula Mazda maximum bodywork width behind front wheels increases to 51.97 inches. · FA MSR Formula Mazda FMzR added to Table 2 classification. · P2 side body height requirement clarified: outermost surface between wheel openings must equal front axle centerline height. · P2 closed cockpit single seat cars now prohibited unless specifically allowed in Table 1. · P2 engine table wording updated; redundant effective date language removed. · P2 motorcycle engines: 2011+ Kawasaki restrictor reduced to 34mm, minimum weight raised to 1100 lbs; 2009+ other brands weight raised to 1100 lbs. · FA BDA engine displacement specification line added to Table 1, effective 2023-01-01. · Sebeco NP01-EVO and Elan NP01 Mazda 2.0L MZR added to P2, 1600 lb minimum, no restrictor required. · P2 Radical SR3/SR4/Cup/Club Sport/Pro-Sport/PR6 removes assisted shifting requirement across all spec lines. · P2 chassis rules clarified to allow composite materials in non-fully-composite construction; anti-intrusion panel attachment standardized; Stohr and converted F600 cars added with specific allowances. · Unable to summarize: the change to P2 Engine Table Spec Line B.1 is not detailed in the provided text. · STL Spec MX5 clutch, wheels, and tyres specified: ACT 0000-02-5004-G6, 17x8 wheels, Toyo RR and RA1 235-40-17. · Formula Renault 2.0 (10-17) reclassified from FX to FA; weight reduced to 1280 lbs, restrictor removed. · FA Swift 016 2.3L restrictor increases from 31mm to 32mm SIR; minimum weight drops 30 lbs to 1420. · Pro Formula Mazda allows street or bridge port, unrestricted apex seals, 70mm throttle body, 99cm wing height max, 132cm bodywork width max. · FA Ligier JS F3 must comply with Formula Regional Americas rules instead of FIA Formula 3 Regional Technical Regulations. · FA sealed engines must undergo full inspection; competitor pays reassembly and resealing costs. · FA Formula Lites FL15 and FR Americas Ligier JS F3 engine sealing requirements clarified to reference respective series technical regulations. · P2 chassis construction rules clarified: fully composite or partially composite requiring composite for mobility allowed; partial composite must roll without composite parts. · P2 classification wording cleaned up in GCR section 9.1.8.C and Contents. · FA transmission rule clarified: transverse shafts prohibited except final drive and motorcycle gearbox in Formula 1000. · FA Swift 016 2.5 liter aero spec now references 2.3 liter notes instead of N notes. · P2 Oldsmobile cam rules clarify aftermarket manufacturer requirements; wording only. · FA Pro Formula Mazda now allows street port or bridge port, previously porting was prohibited. · P2 adds Beasley B2 spec line with 1350 lbs, Mazda 12A, 40.5mm venturi, 16.5in wing. · P2 wing specs correct terminology from 'cord' to 'chord' for 16.5in single or dual element wings. · P2 Converted F5 cars reclassified as Converted F500 cars; suspension must comply with F500 requirements, minimum width 55 inches. · STU normally aspirated engines: minimum weights reduced up to 310 lbs; single throttle body weight reduction removed. · STL and STU Improved Touring vehicles must conform to 9.1.4 Tires & Wheels requirements. · FA adds Honda K20Z3 2.0L engine spec at 1350 lbs minimum and Mazda MZR 2.0L spec at 1300 lbs minimum to Table 1. · P2 motorcycle engines increase to 1505cc max, two-stroke to 1205cc max; automotive engines gain 50 lbs minimum weight to 1350. · P2 Control Area definition narrowed; aerodynamic attachments and vertical structures like turning vanes now prohibited. · STL and STU piston engines clarified: intake manifold and cylinder head porting remains free. · STL Mazda Renesis flat plate restrictor increases from 55mm to 60mm. · STL Mazda RX-7 12A 79-85 clarifies carburetor, emissions, and water jacket modification rules. · P2 Engine Table Spec Line B.1 changed effective 1-1-22, details not provided in excerpt. · P2 Control Area definition clarified: floor extensions and aerodynamic attachments on bottom or top side now explicitly included. · FA Mazda MZR 2.0 spec line removes redundant '2.0' designation; Honda Civic K20Z3 spec line unchanged. · P2 CN Honda K20A-FD2 engine rebuild rules clarified: machining prohibition replaced with specific restrictions on balancing, porting, polishing, valve jobs, cylinder honing. · STL Spec MX-5 removes redundant specification line; no performance change. · FA Toyota 1800 moves from Table 1 to Table 2 (Spec Line Cars). · FA Swift 016 Mazda MZR/Ford Duratec wheel width specification clarified: front 10, rear 14 minimum and 15 maximum. · Converted F5 cars in P2 minimum width reduced to 55 inches from F5 spec. · P2 clarifies minimum body width requirement between front and rear wheels for Ralt RT40, RT41, Swift 008, 014. · FA rule wording clarified: Table 1 for purpose-built and ex-pro cars, Table 2 for spec line cars with exceptions noted. · FA Mazda MZR/Ford Duratec 2296cc and 2500cc moved from Table 1 to Table 2. · FA Mazda MZR 2.0 and Honda Civic K20Z3 remove sequential designation from 5-speed transmission spec. · FA Mazda MZR 2.0 limited to Ralt RT40, RT41, Swift 008, 014 chassis; Honda Civic K20Z3 removes Swift 016 chassis. · STL Volkswagen 2.0L TFSI 1984cc classified with turbocharger removal required, meeting all other STL specs. · FA Swift 016 2.3 liter engine name corrected to Mazda MZR/Ford Duratec. · FA Swift 016 2.5 liter engine name corrected to Mazda MZR/Ford Duratec. · FA removes four spec lines and replaces Ford Duratec/Mazda MZR with Honda B16 at 1615cc, 1175 lbs minimum. · P2 tonneau covers now allowed to meet minimum dimensions; equipment attachment requirements clarified. · P2 multiple chassis models remove effective dates from Table 1 specifications. · P2 engines limited to 4 valves per cylinder maximum across all three spec lines. · STL Pontiac Solstice/Saturn Sky allowed 4" ride height. · STL Mazda B5 DOHC added to classification with standard STL regulations. · STL Honda B16A JDM restrictor reduced from 54mm to 53mm. · FA Spec Line C loses 25 lbs to 1175; Line I loses 75 lbs to 1175; Line K gains 15 lbs to 1175. · FA purpose built and ex-Pro Atlantic cars lose 25 lb sequential transmission penalty wording. · FA Ligier JS F3 car name corrected in FR Americas spec line. · FA Ford Duratec/Mazda MZR 2500 spec line D wording cleanup: 4-valve becomes 4 valves per cylinder. · FA Honda Civic K20Z3 intake manifold and throttle body assembly now allows AT Power Direct-To-Head 45mm individual throttle bodies as alternative to HPD parts. · ST oil coolers and filters now explicitly allowed to be added or substituted; wording clarifies existing permissions. · FA Ford Duratec/Mazda MZR intake restrictor reduced from 32mm to 30mm SIR; Swift 016 2.5 Mazda restrictor reduced from 35mm to 33mm SIR. · FA Toyota 4A-GE engines cleaned up, spec lines A and B engine designations corrected. · FA Ford BD Series max displacement increases from 1600 to 1615 cc, minimum weight stays 1200 lbs. · FA Ford Duratec/Mazda MZR and Honda B16 both now 1615cc max displacement; Honda B16 removes NA requirement. · FA Pro Formula Mazda engine specs moved from Table 1 to Table 2 notes; Renesis Rotary details consolidated. · FA F3 Americas spec line updated effective 2021-03-01; specific changes not legible in provided text. · P2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front and 14-15 rear wheel width. · STL GM Ecotec engines now permit any combination within the family, must use 55mm flat plate restrictor. · STL/STU 90-05 Mazda Miata gains approval for Mazda Motorsports Development alternate front wheel hubs. · ST cars may relocate ABS actuation hardware and wiring anywhere in engine compartment. · STL rear wing trailing edge, including end plates and gurney flap, maximum rearward mounting clarified to center of rearmost bodywork. · STL allows OEM gear sets from same manufacturer transmissions with input shaft modifications for fitment. · Formula Lites Crawford FL15 newly classified in FA. · STL RWD strut suspension weight penalty cut to 0.5%, other RWD cut to 2.5%. · STL Honda F20C loses 2% weight penalty, minimum weight reduced by approximately 35 lbs. · STL Honda B16/B17/B18C1 restrictor tightened to 53mm; B18C variants and Mazda MZR to 52mm. · P2 Honda K20A-FD2 intake restrictor reduced from 55mm to 50mm, making cars faster. · ST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch. · P2 rear wing requirements clarified: standard wing 6×12 inches, end plates 14-inch square; alternate 110cm width wing 9×18 inches, end plates 14×18 inches. · STL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis adjustments. · STL and STU rear wing rules clarify that wicker is a Gurney flap; no performance change. · FA stock engines not given weight adjustment; modified engines now allowed in class. · GT3 and STU add Borg-Warner EFR6258 to approved turbocharger list. · FA engine modifications wording clarified: bore/crankshaft/stroke/flywheel unrestricted if displacement limit met, distributor/transistor ignition allowed without engine modification, compression ratio increasable by machining/gasket chang… · FA transmission rules clarified: no more than five forward speeds and operational reverse gear unless Table 2 notes otherwise. · FA Swift 016 Mazda Duratec Gurney flap wording clarified; terminology and mounting rules unchanged. · Elan NP01 classified in P2 Table 1 as Spec Line car with 2000cc displacement and P2 Engine Table restrictor. · STL adds 2016-2019 Mazda MX-5 Global Cup at 2000cc, 2450-2550 lbs minimum weight. · STL Mazda MX-5 Club Model 06-15 allows Mazda header part number 0000-06-5407-NC. · STL Honda/Acura B18 non-C gets 54mm restrictor; B18C variants drop B18C1, get 53mm restrictor. · FA Volkswagen 1835cc SOHC removed from Table 1. · FA engine rules clarified: blocks and heads must be OEM unless Tables note exceptions. · P2 Enterprises Sports Racer adds 55mm flat plate intake restrictor Part # WM303013 as alternative to SIR. · STL Honda B18 restrictor reduced from 54mm to 53mm flat plate; B18C1 added with 54mm restrictor. · FA Formula 1000 motorcycle-based engine compression ratio raised to 14.5:1 from 13.5:1. · FA removes Ex-FSV front wheel width 6–8 inches and rear 8–10 inches provisions; all cars use front 10 inches, rear 14–15 inches. · FA Formula 3 engines now allowed through 2017, previously 2008, with 30mm restrictor required. · P2 Enterprise Sports Racer 2.3L engine now requires SIR or Flat Plate restrictor sized in 0.5mm increments. · STU GM Ecotech LNF now allowed with turbo removed or with LE5 head and intake manifold, meeting STL specs. · STL Mazda MZR restrictor reduced from 54 mm to 53 mm. · STL Mazda MZR restrictor reduced from 55 mm to 53 mm. · FA engine note clarification removes Table E reference, Pro Formula Mazda directed to Table 1. · P2 fly-by-wire throttle control wording clarified: stock ECUs with drive-by-wire must activate original throttle shaft mechanism. · STL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL. · Formula 1000 motorcycle-based engine classified into FA, throttle bodies and ECUs unrestricted. · F1000 reclassified into FA with specification changes effective 2020-01-01. · FA Swift 016 2.3L Mazda Duratec restrictor reduced from 33mm to 31mm SIR, making it slower. · P2 adds BMW to motorcycle-based engine options in 4-cycle line alongside Kawasaki, Suzuki, Yamaha, Honda. · FA wheel dimension rules moved from Bodywork subsection to General section; no specification changes. · FA Mazda MZR 2.0 now limited to Ralt RT40, Ralt RT41, and Swift 014 chassis only. · FA Honda Civic K20Z3 engines consolidated: three separate base/uprated specs removed, replaced with single unified 1350 lb minimum weight spec for Swift 014/016. · P2 Honda K20A-FD2 non-composite chassis must use 55mm flat plate intake restrictor at 1500 lbs minimum weight. · Mazda Spec MX-5 Challenge classified in STL with 2000cc displacement and 2500 lbs minimum weight. · FA Swift 014 Mazda MZR 2.0 piston minimum weight reduced from 320g to 280g. · P2 motorcycle engines: Stock restrictor 36.5mm to 35mm, modified 37.5mm to 34mm; B.5 restrictor 37.5mm to 33mm. All weights increase 25 lbs. · P2 cars limited to power application on maximum two wheels, effective 2019-07-01. · STU alternate intake manifolds now allowed case-by-case instead of prohibited. · P2 Enterprise minimum weight increases to 1375 lbs; peak horsepower of sealed ESR engine reduced per CRB specification. · FA Line N minimum weight increases to 1375 lbs. · STL Acura/Honda B18 except C engine restrictor increases from 53mm to 54mm flat plate. · FA cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs. · STL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld. · FA Formula 3 car sequential gearbox weight penalty of 25 lbs removed; minimum weight now 1215 lbs. · P2 stock engine restrictor shrinks to 35.0mm and weight rises to 1025 lbs; modified engine restrictor to 34.0mm, weight to 1125 lbs; line B.5 restrictor to 33.0mm, weight to 1185 lbs. · P2 Line A.1 restrictor reduced from 40mm to 38mm. · STL adds VW 1.8L R4 20VT 1781cc, 1 minimum weight, turbo removed permitted. · STL Mazda Renesis minimum weight reduced from 2800 to 2700 lbs. · STL Mazda MX-5 Cup brake pad compound changed to open. · STL adds Acura/Honda B18C1 GSR with 54mm flat plate restrictor and port matching limited to 1 inch. · STL Mazda 12 and 13B now permit port matching; previous ban removed. · FA Swift 014-Mazda MZR 2.0 engine now requires OE block casting #LF95 and specific OE components instead of sealed Elite Engines sourcing. · FA Swift 016 Mazda Duratec 2.3L and 2.5L minimum weight increases from 1420 to 1450 lbs. · P2 Spec Line cars now allow 1345cc Hayabusa stock engines at 1050 lbs with 30mm restrictor. · P2 Group CN Honda K20A-FD2 55mm restrictor implementation delayed from 1/1/2019 to 3/1/2019. · P2 Honda K20A-FD2 in CN chassis must use stock intake manifold with 64mm throttle body and 55mm restrictor at 1500 lbs minimum weight. · STL B18C Type R variants get 54mm flat plate restrictor; B17 also gets 54mm restrictor. · STL Mazda Miata removes maximum displacement limit and adjusts minimum weight.showhide
FA Classify FR European Championship car as spec line car in Table 2 #37658cars addedneutralFA adds Tatuus F.3 T-318 or FR-19 as spec line car in Table 2 for Formula Regional European Championship.
P2 2000 cc Pinto Engine Car Weight #37187weightslowerP2 2000cc Pinto engine car minimum weight set to 1335 lbs.
STL Request to Remove Miata Hubs from General category #37138wordingneutralSTL/STU: 90-05 Mazda Miata alternate front wheel hubs moved from General to specific part approval.
P2 E&O - Correct FIA Group CN spec line notes #35900wordingneutralP2 FIA Group CN spec notes clarified: Series changed to Challenge, documentation requirement moved to online link.
STL ST Electric-Assisted Steering Systems #35066wordingneutralSTL and STU power steering rules clarified to permit electric-assisted and hydraulic-assisted steering systems.
STL BOP Adjustments #35112inductionfasterSTL Acura/Honda B-series and Mazda MZR restrictors reduced 2mm; minimum weights down 25–75 lbs for 1900–2000cc engines.
STL Mazda 12A #35320engineslowerSTL Mazda 12A must keep 5th and 6th intake port actuators and valves, no longer allowed removal or disabling.
P2 E&O - Clarify B.1 modified engine range in AMAC spec lines #35225wordingneutralP2 AMAC modified engine range clarified to 2008 and older stock engines only, restrictor 38mm, weight 1025 lbs.
P2 Replacement Engine Crankcase for 07/08 Suzuki GSX-R1000 Engines #35340engineunclearP2 Suzuki GSX-R1000 07/08 engine crankcase may swap to GSX-S1000 16/19 part #11301-04840.
STL Alternate Carburetor Request for 79-85 RX7 12a #35181inductionunclearSTL Mazda RX-7 12A (79-85) now allows auto-type 2 bbl with 42mm choke(s) on dual-y manifold as alternate to stock Nikki 4 bbl.
P2 Correct Table 1 for Engine Date Range Specifications #35182wordingneutralP2 Table 1 corrects engine date ranges and brand specifications for Stock and Modified engines across multiple car models.
FA Simplify Pro Formula Mazda wheel allowance #34190tyres & wheelsunclearFA Pro Formula Mazda front wheels widen to 10 in. max; rear wheels narrow to 14 in. min.
STL Clarify STL table B - IT spec notes on Tires #34187wordingneutralSTL ITA/ITS RX7 and 1985+ ITA/ITS/ITB/ITC vehicles clarified to conform to section 9.1.4.2 tire specifications.
FA E&O - Correct Pro Formula Mazda spec line dimensional equivalent #34085aerofasterFA Pro Formula Mazda maximum bodywork width behind front wheels increases to 51.97 inches.
FA Add new spec line for MSR Formula Mazda FMzR to Table 2 #34139cars addedneutralFA MSR Formula Mazda FMzR added to Table 2 classification.
P2 Clarify minimum side body height requirement #34143wordingneutralP2 side body height requirement clarified: outermost surface between wheel openings must equal front axle centerline height.
P2 Clarify closed cockpit single seat car allowance #34144wordingneutralP2 closed cockpit single seat cars now prohibited unless specifically allowed in Table 1.
P2 Remove redundant effective date language and update engine table #34012wordingneutralP2 engine table wording updated; redundant effective date language removed.
P2 E&O - Correct dimensional equivalents #34038engineslowerP2 motorcycle engines: 2011+ Kawasaki restrictor reduced to 34mm, minimum weight raised to 1100 lbs; 2009+ other brands weight raised to 1100 lbs.
FA BDA Displacement #33431wordingneutralFA BDA engine displacement specification line added to Table 1, effective 2023-01-01.
P2 Request to Classify Sebeco NP01 #33378cars addedneutralSebeco NP01-EVO and Elan NP01 Mazda 2.0L MZR added to P2, 1600 lb minimum, no restrictor required.
P2 Radical spec line clarifications #33485wordingneutralP2 Radical SR3/SR4/Cup/Club Sport/Pro-Sport/PR6 removes assisted shifting requirement across all spec lines.
P2 E&O original class intent #33519wordingneutralP2 chassis rules clarified to allow composite materials in non-fully-composite construction; anti-intrusion panel attachment standardized; Stohr and converted F600 cars added with specific allowances.
P2 Update Engine Table Spec Line B.1 #33608engineunclearUnable to summarize: the change to P2 Engine Table Spec Line B.1 is not detailed in the provided text.
STL Spec MX5 in STL #33473wordingneutralSTL Spec MX5 clutch, wheels, and tyres specified: ACT 0000-02-5004-G6, 17x8 wheels, Toyo RR and RA1 235-40-17.
FA Reclassify 2010-2017 Formula Renault 2.0 as a spec line car in FA #33395cars addedfasterFormula Renault 2.0 (10-17) reclassified from FX to FA; weight reduced to 1280 lbs, restrictor removed.
FA Change Swift 016 2.3L restrictor size and minimum weight #33472induction -30 lbsfasterFA Swift 016 2.3L restrictor increases from 31mm to 32mm SIR; minimum weight drops 30 lbs to 1420.
FA Pro Formula Mazda Dimension E&O #33160wordingneutralPro Formula Mazda allows street or bridge port, unrestricted apex seals, 70mm throttle body, 99cm wing height max, 132cm bodywork width max.
FA Update FR Americas rulebook requirement #32491wordingneutralFA Ligier JS F3 must comply with Formula Regional Americas rules instead of FIA Formula 3 Regional Technical Regulations.
FA Clarify verification of sealed engine compliance #32522wordingneutralFA sealed engines must undergo full inspection; competitor pays reassembly and resealing costs.
FA Clarify Formula Lites and FR Americas sealed engine requirement #32523wordingneutralFA Formula Lites FL15 and FR Americas Ligier JS F3 engine sealing requirements clarified to reference respective series technical regulations.
P2 E&O Clarification of Chassis Construction Requirements #32469wordingneutralP2 chassis construction rules clarified: fully composite or partially composite requiring composite for mobility allowed; partial composite must roll without composite parts.
P2 Clean up P2 wording #32525wordingneutralP2 classification wording cleaned up in GCR section 9.1.8.C and Contents.
FA E&O FA Transmission section #32251wordingneutralFA transmission rule clarified: transverse shafts prohibited except final drive and motorcycle gearbox in Formula 1000.
FA E&O Swift 016 2.5 liter Aero column #32363wordingunclearFA Swift 016 2.5 liter aero spec now references 2.3 liter notes instead of N notes.
P2 After Market to Aftermarket #32373wordingneutralP2 Oldsmobile cam rules clarify aftermarket manufacturer requirements; wording only.
FA Closing the Gap #31934inductionfasterFA Pro Formula Mazda now allows street port or bridge port, previously porting was prohibited.
P2 Add spec line for Beasley B2 #32147cars addedneutralP2 adds Beasley B2 spec line with 1350 lbs, Mazda 12A, 40.5mm venturi, 16.5in wing.
P2 E&O Table 1 spec line wing terminology #32148wordingneutralP2 wing specs correct terminology from 'cord' to 'chord' for 16.5in single or dual element wings.
P2 E&O class name #32196wordingneutralP2 Converted F5 cars reclassified as Converted F500 cars; suspension must comply with F500 requirements, minimum width 55 inches.
STL Single TB Weight Modifiers #31449weightfasterSTU normally aspirated engines: minimum weights reduced up to 310 lbs; single throttle body weight reduction removed.
STL Improved Touring Tires #32063tyres & wheelsneutralSTL and STU Improved Touring vehicles must conform to 9.1.4 Tires & Wheels requirements.
FA Reorganize Tables 1 and 2 #31985cars addedneutralFA adds Honda K20Z3 2.0L engine spec at 1350 lbs minimum and Mazda MZR 2.0L spec at 1300 lbs minimum to Table 1.
P2 E&O Engine section #31969enginefasterP2 motorcycle engines increase to 1505cc max, two-stroke to 1205cc max; automotive engines gain 50 lbs minimum weight to 1350.
P2 E&O letter #31539 – Control Area definition #31783aeroslowerP2 Control Area definition narrowed; aerodynamic attachments and vertical structures like turning vanes now prohibited.
STL Throttling Device Clarification #31323wordingneutralSTL and STU piston engines clarified: intake manifold and cylinder head porting remains free.
STL Mazda Renesis Restriction #31467inductionfasterSTL Mazda Renesis flat plate restrictor increases from 55mm to 60mm.
STL Clarification of 79-85 RX7 Spec line #31621wordingneutralSTL Mazda RX-7 12A 79-85 clarifies carburetor, emissions, and water jacket modification rules.
P2 BoP adjustment effective 1-1-22 #31538wordingunclearP2 Engine Table Spec Line B.1 changed effective 1-1-22, details not provided in excerpt.
P2 E&O clarification of "Control Area" definition #31539wordingneutralP2 Control Area definition clarified: floor extensions and aerodynamic attachments on bottom or top side now explicitly included.
FA E&O Table 2 engine names #31085wordingneutralFA Mazda MZR 2.0 spec line removes redundant '2.0' designation; Honda Civic K20Z3 spec line unchanged.
P2 P2 CN Engine Rebuild Clarification #31000wordingneutralP2 CN Honda K20A-FD2 engine rebuild rules clarified: machining prohibition replaced with specific restrictions on balancing, porting, polishing, valve jobs, cylinder honing.
STL Request to clean up Spec MX-5 Redundancy #31069wordingneutralSTL Spec MX-5 removes redundant specification line; no performance change.
FA Move Toyota 1800 to Table 2 #30822cars addedneutralFA Toyota 1800 moves from Table 1 to Table 2 (Spec Line Cars).
FA E&O Swift 016 wheel width reference #30939wordingneutralFA Swift 016 Mazda MZR/Ford Duratec wheel width specification clarified: front 10, rear 14 minimum and 15 maximum.
P2 F5 P2 Conversion #30856aerofasterConverted F5 cars in P2 minimum width reduced to 55 inches from F5 spec.
P2 Clarify minimum body width requirement #30859wordingneutralP2 clarifies minimum body width requirement between front and rear wheels for Ralt RT40, RT41, Swift 008, 014.
FA Update FA rules package #30717wordingneutralFA rule wording clarified: Table 1 for purpose-built and ex-pro cars, Table 2 for spec line cars with exceptions noted.
FA Move Mazda MZR/Ford Duratec 2296cc and 2500cc to Table 2 #30718wordingneutralFA Mazda MZR/Ford Duratec 2296cc and 2500cc moved from Table 1 to Table 2.
FA Clean up Table 2 Mazda MZR 2.0L and Honda Civic K20Z3 spec lines #30719wordingneutralFA Mazda MZR 2.0 and Honda Civic K20Z3 remove sequential designation from 5-speed transmission spec.
FA E&O Mazda MZR 2.0 and Honda Civic K20Z3 chassis eligibility #30632wordingneutralFA Mazda MZR 2.0 limited to Ralt RT40, RT41, Swift 008, 014 chassis; Honda Civic K20Z3 removes Swift 016 chassis.
STL VW Engine Request #30625engineslowerSTL Volkswagen 2.0L TFSI 1984cc classified with turbocharger removal required, meeting all other STL specs.
FA Correct engine name in Swift 016 2.3 liter spec line #30447wordingneutralFA Swift 016 2.3 liter engine name corrected to Mazda MZR/Ford Duratec.
FA Correct engine name in Swift 016 2.5 liter spec line #30448wordingneutralFA Swift 016 2.5 liter engine name corrected to Mazda MZR/Ford Duratec.
FA Revise Table 1 Spec Lines and clarify application of Engine Notes #30456cars addedunclearFA removes four spec lines and replaces Ford Duratec/Mazda MZR with Honda B16 at 1615cc, 1175 lbs minimum.
P2 E&O tonneau cover provision in cockpit opening section #30459wordingneutralP2 tonneau covers now allowed to meet minimum dimensions; equipment attachment requirements clarified.
P2 Remove effective dates in Table 1 #30468wordingneutralP2 multiple chassis models remove effective dates from Table 1 specifications.
P2 E&O Maximum Valves Per Cylinder #30560engineneutralP2 engines limited to 4 valves per cylinder maximum across all three spec lines.
STL Request Mazda B5 DOHC #30420cars addedneutralSTL Mazda B5 DOHC added to classification with standard STL regulations.
STL Honda B16A (JDM) Restrictor change #30531inductionslowerSTL Honda B16A JDM restrictor reduced from 54mm to 53mm.
FA Update Table 1 Weights for Spec Lines C, I, and K #30355weight -25 lbsfasterFA Spec Line C loses 25 lbs to 1175; Line I loses 75 lbs to 1175; Line K gains 15 lbs to 1175.
FA Remove redundant reference in Table 2 spec line #30366wordingfasterFA purpose built and ex-Pro Atlantic cars lose 25 lb sequential transmission penalty wording.
FA Correct the name of the FR Americas car #30369wordingneutralFA Ligier JS F3 car name corrected in FR Americas spec line.
FA Clean up Spec Line D in Table 1 #30372wordingneutralFA Ford Duratec/Mazda MZR 2500 spec line D wording cleanup: 4-valve becomes 4 valves per cylinder.
FA Table 2 Honda K20Z3 request #30386inductionfasterFA Honda Civic K20Z3 intake manifold and throttle body assembly now allows AT Power Direct-To-Head 45mm individual throttle bodies as alternative to HPD parts.
STL ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wordingneutralST oil coolers and filters now explicitly allowed to be added or substituted; wording clarifies existing permissions.
FA E&O FA Intake Restrictors #30273inductionslowerFA Ford Duratec/Mazda MZR intake restrictor reduced from 32mm to 30mm SIR; Swift 016 2.5 Mazda restrictor reduced from 35mm to 33mm SIR.
FA Clean up Spec Lines A and B in Table 1 #30274wordingneutralFA Toyota 4A-GE engines cleaned up, spec lines A and B engine designations corrected.
FA Clean up Spec Line C in Table 1 #30275enginefasterFA Ford BD Series max displacement increases from 1600 to 1615 cc, minimum weight stays 1200 lbs.
FA Clean up Spec Lines J and L in Table 1 #30276wordingneutralFA Ford Duratec/Mazda MZR and Honda B16 both now 1615cc max displacement; Honda B16 removes NA requirement.
FA Move engine specifications to Pro Formula Mazda spec line notes #30278wordingneutralFA Pro Formula Mazda engine specs moved from Table 1 to Table 2 notes; Renesis Rotary details consolidated.
FA Update F3 Americas spec line #30280wordingunclearFA F3 Americas spec line updated effective 2021-03-01; specific changes not legible in provided text.
P2 Add a new spec line for a 2-cycle, 3-cylinder engine up to 820cc #30272cars addedneutralP2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front and 14-15 rear wheel width.
STL GM Ecotec engines in STL #30247wordingneutralSTL GM Ecotec engines now permit any combination within the family, must use 55mm flat plate restrictor.
STL Super Touring Alternate Miata Hubs #30345wordingneutralSTL/STU 90-05 Mazda Miata gains approval for Mazda Motorsports Development alternate front wheel hubs.
STL Brake Component Relocation #29990wordingneutralST cars may relocate ABS actuation hardware and wiring anywhere in engine compartment.
STL Super Touring Wing Clarification #30111aeroneutralSTL rear wing trailing edge, including end plates and gurney flap, maximum rearward mounting clarified to center of rearmost bodywork.
STL Transmission Options #30118wordingneutralSTL allows OEM gear sets from same manufacturer transmissions with input shaft modifications for fitment.
FA Request to classify Formula Lites Crawford FL15 #29702cars addedneutralFormula Lites Crawford FL15 newly classified in FA.
STL Request for FWD and RWD Parity #29728weightfasterSTL RWD strut suspension weight penalty cut to 0.5%, other RWD cut to 2.5%.
STL Request to Remove Honda F20C 2% Weight Penalty #29815weightfasterSTL Honda F20C loses 2% weight penalty, minimum weight reduced by approximately 35 lbs.
STL Request for FWD and RWD Parity #30023inductionslowerSTL Honda B16/B17/B18C1 restrictor tightened to 53mm; B18C variants and Mazda MZR to 52mm.
P2 Balance of Performance adjustments effective 01-01-2021 #29822inductionfasterP2 Honda K20A-FD2 intake restrictor reduced from 55mm to 50mm, making cars faster.
STL Request clarification on wing measurement #29640aeroneutralST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch.
P2 E&O clarification of P2 rear wing requirements #29205aeroneutralP2 rear wing requirements clarified: standard wing 6×12 inches, end plates 14-inch square; alternate 110cm width wing 9×18 inches, end plates 14×18 inches.
STL Minimum Weight Determination #27695wordingneutralSTL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis adjustments.
STL ST Gurney flap Wicker clarification #29012wordingneutralSTL and STU rear wing rules clarify that wicker is a Gurney flap; no performance change.
FA Request to Adjust FB Weight for Stock Engines #29005wordingneutralFA stock engines not given weight adjustment; modified engines now allowed in class.
STL Request for Addition to GT3 Approved Turbo List #27576wordingneutralGT3 and STU add Borg-Warner EFR6258 to approved turbocharger list.
FA E&O permitted engine modifications #28831wordingneutralFA engine modifications wording clarified: bore/crankshaft/stroke/flywheel unrestricted if displacement limit met, distributor/transistor ignition allowed without engine modification, compression ratio increasable by machining/gasket chang…
FA E&O Transmissions #28832wordingneutralFA transmission rules clarified: no more than five forward speeds and operational reverse gear unless Table 2 notes otherwise.
FA Swift 016 Gurney flap wicker clarification #28884wordingneutralFA Swift 016 Mazda Duratec Gurney flap wording clarified; terminology and mounting rules unchanged.
P2 Classify Elan NP01 in P2 Table 1 #28812cars addedneutralElan NP01 classified in P2 Table 1 as Spec Line car with 2000cc displacement and P2 Engine Table restrictor.
STL Request to add 2016-2019 GMX-5 Spec line #28604cars addedneutralSTL adds 2016-2019 Mazda MX-5 Global Cup at 2000cc, 2450-2550 lbs minimum weight.
STL Request to update PN for MX-5 #28622wordingunclearSTL Mazda MX-5 Club Model 06-15 allows Mazda header part number 0000-06-5407-NC.
STL Correction - Clarification Honda/Acura B18B engine Letter # 26209 #28873inductionunclearSTL Honda/Acura B18 non-C gets 54mm restrictor; B18C variants drop B18C1, get 53mm restrictor.
FA Remove redundant spec line in Table 1 #28720removedneutralFA Volkswagen 1835cc SOHC removed from Table 1.
FA E&O general engine rules #28772wordingneutralFA engine rules clarified: blocks and heads must be OEM unless Tables note exceptions.
P2 SCCA Enterprises ESR / P2 engine restrictor testing #28669engineneutralP2 Enterprises Sports Racer adds 55mm flat plate intake restrictor Part # WM303013 as alternative to SIR.
STL STL Honda B18 restrictor changes #28794inductionfasterSTL Honda B18 restrictor reduced from 54mm to 53mm flat plate; B18C1 added with 54mm restrictor.
FA Request higher compression ratio and prior weights for F1000 cars #28162enginefasterFA Formula 1000 motorcycle-based engine compression ratio raised to 14.5:1 from 13.5:1.
FA Remove redundant wheel dimension provisions #28554wordingneutralFA removes Ex-FSV front wheel width 6–8 inches and rear 8–10 inches provisions; all cars use front 10 inches, rear 14–15 inches.
FA E&O Formula 3 spec line #28596enginefasterFA Formula 3 engines now allowed through 2017, previously 2008, with 30mm restrictor required.
P2 Add ESR inlet restrictor #27869inductionslowerP2 Enterprise Sports Racer 2.3L engine now requires SIR or Flat Plate restrictor sized in 0.5mm increments.
STL Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0 #27884engineslowerSTU GM Ecotech LNF now allowed with turbo removed or with LE5 head and intake manifold, meeting STL specs.
STL Acura/Honda B18C engine chart. Reduce the current 54 mm flat plat #28663inductionslowerSTL Mazda MZR restrictor reduced from 54 mm to 53 mm.
STL Mazda MZR engine chart. Reduce the current 55 mm flat plate to 53 #28664inductionslowerSTL Mazda MZR restrictor reduced from 55 mm to 53 mm.
FA FA weight correction/clarification #28430wordingneutralFA engine note clarification removes Table E reference, Pro Formula Mazda directed to Table 1.
P2 Request for Fly by Wire Rule Wording Change #28247wordingneutralP2 fly-by-wire throttle control wording clarified: stock ECUs with drive-by-wire must activate original throttle shaft mechanism.
STL Request to add wheel part numbers #28342wordingneutralSTL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL.
FA Request to merge FB into FA #25611cars addedfasterFormula 1000 motorcycle-based engine classified into FA, throttle bodies and ECUs unrestricted.
FA Suggestions for FB/F1000 into FA #27319cars addedunclearF1000 reclassified into FA with specification changes effective 2020-01-01.
FA Change Swift 016 - 2.3 liter Mazda Duratec restrictor size #27880inductionslowerFA Swift 016 2.3L Mazda Duratec restrictor reduced from 33mm to 31mm SIR, making it slower.
P2 Request for addition of BMW Engine in P2 Engine Table #27821cars addedneutralP2 adds BMW to motorcycle-based engine options in 4-cycle line alongside Kawasaki, Suzuki, Yamaha, Honda.
FA Move wheel dimensions from Bodywork subsection to #27493wordingneutralFA wheel dimension rules moved from Bodywork subsection to General section; no specification changes.
FA Table 2 Mazda MZR 2.0 E&O #27640wordingneutralFA Mazda MZR 2.0 now limited to Ralt RT40, Ralt RT41, and Swift 014 chassis only.
FA Follow up to Letter #27344 on Honda Powered FA Rules #27363wordingneutralFA Honda Civic K20Z3 engines consolidated: three separate base/uprated specs removed, replaced with single unified 1350 lb minimum weight spec for Swift 014/016.
P2 Update Engine Table Line E notes #27414inductionslowerP2 Honda K20A-FD2 non-composite chassis must use 55mm flat plate intake restrictor at 1500 lbs minimum weight.
STL Request to Classify Spec MX-5 Challenge in STL #27399cars addedneutralMazda Spec MX-5 Challenge classified in STL with 2000cc displacement and 2500 lbs minimum weight.
FA Swift 014 Mazda MZR 2.0 E&O #27305enginefasterFA Swift 014 Mazda MZR 2.0 piston minimum weight reduced from 320g to 280g.
P2 Update P2 Engine Table spec lines to reflect 3/1/2019 #27254inductionslowerP2 motorcycle engines: Stock restrictor 36.5mm to 35mm, modified 37.5mm to 34mm; B.5 restrictor 37.5mm to 33mm. All weights increase 25 lbs.
P2 E&O Transmissions #27006otherslowerP2 cars limited to power application on maximum two wheels, effective 2019-07-01.
STL Request clarification for manifold and throttle in STU #27004inductionfasterSTU alternate intake manifolds now allowed case-by-case instead of prohibited.
P2 Request to restrict all cars #26246weightslowerP2 Enterprise minimum weight increases to 1375 lbs; peak horsepower of sealed ESR engine reduced per CRB specification.
FA Adjust Line N restrictor size and minimum weight #26691weight +30 lbsslowerFA Line N minimum weight increases to 1375 lbs.
STL Request Restrictor Plate correction #26779inductionfasterSTL Acura/Honda B18 except C engine restrictor increases from 53mm to 54mm flat plate.
FA Add data plate requirement #26707wordingneutralFA cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs.
STL Request Ride Height Clarification #26597wordingneutralSTL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld.
FA Request to add FA engine spec lines #26183weightfasterFA Formula 3 car sequential gearbox weight penalty of 25 lbs removed; minimum weight now 1215 lbs.
P2 Change Engine Table Lines B.1 & B.5 #25777inductionslowerP2 stock engine restrictor shrinks to 35.0mm and weight rises to 1025 lbs; modified engine restrictor to 34.0mm, weight to 1125 lbs; line B.5 restrictor to 33.0mm, weight to 1185 lbs.
P2 Change Line A.1 restrictor size #26429inductionslowerP2 Line A.1 restrictor reduced from 40mm to 38mm.
STL Request to reduce weight of RX8 with Renesis rotary #25781weight -100 lbsfasterSTL Mazda Renesis minimum weight reduced from 2800 to 2700 lbs.
STL Request for Open Brake Pads On Mazda MX-5 Cup NC #25821wordingneutralSTL Mazda MX-5 Cup brake pad compound changed to open.
STL Request to clarify B18C1 GSR Honda B motor table #26209cars addedneutralSTL adds Acura/Honda B18C1 GSR with 54mm flat plate restrictor and port matching limited to 1 inch.
STL Port Matching #26415wordingfasterSTL Mazda 12 and 13B now permit port matching; previous ban removed.
FA FA MZR 2.0 Engine Specification #25814wordingneutralFA Swift 014-Mazda MZR 2.0 engine now requires OE block casting #LF95 and specific OE components instead of sealed Elite Engines sourcing.
FA FA 016 weight increase #26063weightslowerFA Swift 016 Mazda Duratec 2.3L and 2.5L minimum weight increases from 1420 to 1450 lbs.
P2 Request to Allow 1345cc Hayabusa Engines for Spec Line P2 Cars #25595enginefasterP2 Spec Line cars now allow 1345cc Hayabusa stock engines at 1050 lbs with 30mm restrictor.
P2 Change CN inlet restrictor implementation date #25816wordingneutralP2 Group CN Honda K20A-FD2 55mm restrictor implementation delayed from 1/1/2019 to 3/1/2019.
P2 Clarify Honda K20A-FD2 parts requirement #25950inductionslowerP2 Honda K20A-FD2 in CN chassis must use stock intake manifold with 64mm throttle body and 55mm restrictor at 1500 lbs minimum weight.
STL Request to equalize FPR Reduction on all B-Series Vtec Engines #24746inductionslowerSTL B18C Type R variants get 54mm flat plate restrictor; B17 also gets 54mm restrictor.
STL Request E&O for Mazda Miata Spec Line #25955wordingunclearSTL Mazda Miata removes maximum displacement limit and adjusts minimum weight.
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 STL" is the class's best as a share of STL'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 STL'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.