FA vs SRF3 vs FP pace at Buttonwillow Raceway Park
Quickest here:FA 1:14.588 Greg Labadie, Cal Club 2023 qualifying · SRF3 1:50.233 Caleb Shrader, Cal Club 2025 qualifying · FP 1:55.440 Michael Lewis, Cal Club 2025 race
FASRF3FPsolid race · dashed qualifying · slower is lower
FASRF3FPsolid race · dashed qualifying · each class's best lap as a share of FA's at the same event (the reference class, changeable above); 100% is level, higher is quicker
Event
FA
SRF3
FP
Qual best
Race best
Trap
Qual best
Race best
Trap
vs FA
% of FA
Qual best
Race best
Trap
vs FA
% of FA
Cal Club 2026 CALCL262026-02-21
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%)
1:50.913Asad Nikadambaev · fastest of 27 · top 5 within 1.1s+0.680s (+0.62%)
1:52.070Asad Nikadambaev · fastest of 27 · top 5 within 0.8s+1.245s (+1.12%)
138.9Paul Marino+20.7 mph (+17.5%)
+14.795squal +15.121s
115.2%qual 115.8%
1:58.084Steven Powers · fastest of 2+1.963s (+1.69%)
1:57.587Michael Lewis · fastest of 3 · top 3 within 2.1s+2.147s (+1.86%)
137.8Daniel Snow+26.9 mph (+24.3%)
+20.312squal +22.292s
120.9%qual 123.3%
45 rule changes (FA: 7, SRF3: 4, FP: 34)11 weight · 8 induction · 6 cars added · 4 engine · 1 aero · 1 tyres & wheels · 13 wording · 1 other · 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. · FP class adds Toyota 5E DOHC 1497cc engine, 1900 lbs minimum weight, 23mm SIR induction. · FP Toyota 4E DOHC 1331cc engine added to Appendix N with 1900 lbs minimum weight. · FP Fiat X1/9 gains dual carburetor options with 28mm side-draft alternates and revised valve/transmission specs. · 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. · EP Triumph TR2-TR4A allows 5-speed gearbox without overdrive; removes Weber carb and weight specification. · EP BMW Z3 2.5L restrictor reduced 52mm to 50mm, weight increased to 2550 lbs base; five other BMW models get smaller restrictors. · FP Lancia Scorpion minimum weight drops 80 lbs, to 1950. · FP Volkswagen Rabbit Convertible no longer required to remove factory roll bar. · FP Acura Integras and Honda Civics gain 50–79 lbs; Mazda Miata and Mercury Capri compression ratio to 11.0:1, valve lift to .425". · FP Honda B/D-series engines gain 105–120 lbs minimum weight across seven variants. · FA class adds USF Pro 2000 car eligibility for Formula Atlantic racing. · EP Nissan 280Z minimum weight reduced from 2560 to 2400 lbs. · EP Mazda MX-5 1.8L 90-97 weight reduced to 2125 lbs from 2150 lbs. · HP Austin-Healey Sprite/Midget 1098cc minimum weight drops 80 lbs to 1550. · HP Volvo 142/142E gains compression ratio limit 12.0:1 and valve lift limit .425". · HP Mini Cooper 07-15 valve lift reduced to .390", from .450". · FP Scirocco 83-88 established as spec line with 1733–1803 lbs, 1715–1780 cc SOHC, 40/33 mm valves, Solex carbs or fuel injection. · FP and HP Volkswagen Rabbit descriptions updated: Convertible changed to Cabriolet in FP; Cabriolet added to three HP engine variants. · EP, FP, HP: rear drum brake to disc conversion clarified; rotors solid, diameter limited to largest front rotor permitted. · EP Ford Mustang (94-98) fuel injected throttle body inside diameter specified at 60. · FP Volkswagen Scirocco: remove two engine variants (1715cc and 1780cc), lighten one variant to 1663 lbs, allow 15×7 wheels instead of 13×7. · HP Plymouth Arrow transmission max speeds clarified to 4 or 5. · EP, FP, HP wheel diameter added to Appendix G as absolute maximum specification. · EP, FP, HP throttle body inside dimensions must remain stock with +/-.25mm tolerance; butterfly dimensions stock in FP, HP only. · SRF3 adds HD Oil Cooler P/N G1148500 as alternative to standard cooler P/N G480503. · SRF3 brakes restructured: Hawk Blue 801993 pads, Wilwood 800065 rotors only; adds Girling 880358, Wilwood 880357, Tilton 880360 master cylinders. · FA Ligier JS F3 front tires may be Hoosier 43363 240/580R13 MS, rear 43368 300/590R13 MS. · EP BMW Z4 03-05 restricted to 52mm flat plate intake restrictor. · EP Fiat 124 Spider 1600 & 2000 weight drops 50 lbs to 2000; carburetors gain 2mm chokes to 36mm. · HP Fiat X-1/9 base weights reduced 50–53 lbs across 1300 and 1500 spec lines. · Chevrolet Spark 16-22 classified HP Pre at 1850 lbs minimum weight, fuel injected, 1399 cc. · HP Ford Festiva 88-93 minimum weight drops to 1600 lbs, variants to 1640 and 1680 lbs; compression ratio raised to 11.0:1. · SRF drivers with disabilities may modify seat and controls for safety and comfort with approval and logbook notation. · SRF SADEV-SRF3 6-speed sequential transmission gear ratios wording clarified, effective 2025-04-01. · FA Formula Renault 2.0 (10-17) spec notes clarified: engine sealed, manual compliance required, tire choice unrestricted, no alterations except repairs. · EP BMW Z3 and 3-series models get smaller intake restrictors: Z3 2.5L to 52mm, Z3 2.8L to 55mm, 328i to 58mm, 325i to 56mm. · FP Acura Integra and Honda Civic models get smaller 51mm intake restrictors, down from 55mm; Del Sol VTEC weight increases to 2290–2405 lbs. · EP, FP, HP: interior or exterior mirrors meeting rule 9.3.36 now permitted. · EP Honda S2000 1997cc base loses 75 lbs to 2375; 2157cc base loses 60 lbs to 2450. · EP Mazda MX-5/Miata 99-05 minimum weight drops to 2100 lbs, 2153 lbs with power adder, 2205 lbs with two adders. · FP GTL Volkswagen Jetta Mark IV 4dr FWD 98.2 wheelbase newly classified. · FP Spec Lines option: carburettor chokes permitted as alternative to SIR, same size as listed SIR.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.
FP Request Toyota 5E Series Engines #38208cars addedcars addedFP class adds Toyota 5E DOHC 1497cc engine, 1900 lbs minimum weight, 23mm SIR induction.
FP Request for Toyota 4E Series Engines #38209cars addedcars addedFP Toyota 4E DOHC 1331cc engine added to Appendix N with 1900 lbs minimum weight.
FP Dual Carbs for the Fiat X1/9 #39593inductionunclearFP Fiat X1/9 gains dual carburetor options with 28mm side-draft alternates and revised valve/transmission specs.
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.
FP TR2 Notes E&O #39180wordingunclearEP Triumph TR2-TR4A allows 5-speed gearbox without overdrive; removes Weber carb and weight specification.
FP Balance of Power #39187induction +50 lbsslowerEP BMW Z3 2.5L restrictor reduced 52mm to 50mm, weight increased to 2550 lbs base; five other BMW models get smaller restrictors.
FP Factory Roll Bar Removal on VW Convertible #39268wordingwordingFP Volkswagen Rabbit Convertible no longer required to remove factory roll bar.
FP FP Parity Request #39325weight +50 lbsslowerFP Acura Integras and Honda Civics gain 50–79 lbs; Mazda Miata and Mercury Capri compression ratio to 11.0:1, valve lift to .425".
FP Adjust former-GTL Honda's with B/D-Series Engines #39374weightslowerFP Honda B/D-series engines gain 105–120 lbs minimum weight across seven variants.
FA Re-Consider USF Pro 2000 Car for Formula Atlantic Class #38783cars addedcars addedFA class adds USF Pro 2000 car eligibility for Formula Atlantic racing.
FP Please Lower Weight of 280Z #38871weight -160 lbsfasterEP Nissan 280Z minimum weight reduced from 2560 to 2400 lbs.
FP Miata Weight Adjustment Follow Up #38949weight -25 lbsfasterEP Mazda MX-5 1.8L 90-97 weight reduced to 2125 lbs from 2150 lbs.
FP HP Volvo 142 spec omission #38994engineslowerHP Volvo 142/142E gains compression ratio limit 12.0:1 and valve lift limit .425".
FP HP Mini DOHC 1.6 #38996engineslowerHP Mini Cooper 07-15 valve lift reduced to .390", from .450".
FP 83-88 FP Scirocco Spec Line Creation #38997cars addedcars addedFP Scirocco 83-88 established as spec line with 1733–1803 lbs, 1715–1780 cc SOHC, 40/33 mm valves, Solex carbs or fuel injection.
FP Add to Rabbit description #39019wordingwordingFP and HP Volkswagen Rabbit descriptions updated: Convertible changed to Cabriolet in FP; Cabriolet added to three HP engine variants.
FP Clean-up 9.1.5.E.7e #39025wordingwordingEP, FP, HP: rear drum brake to disc conversion clarified; rotors solid, diameter limited to largest front rotor permitted.
FP Add TB size to Ford Mustang (94-98) Spec Line #39130wordingwordingEP Ford Mustang (94-98) fuel injected throttle body inside diameter specified at 60.
FP Correct Existing VW Scirocco Spec Line #39140enginefasterFP Volkswagen Scirocco: remove two engine variants (1715cc and 1780cc), lighten one variant to 1663 lbs, allow 15×7 wheels instead of 13×7.
FP HP Plymouth Arrow spec omission #38995wordingwordingHP Plymouth Arrow transmission max speeds clarified to 4 or 5.
FP Add Wheel Diameter to Appendix G #39008wordingwordingEP, FP, HP wheel diameter added to Appendix G as absolute maximum specification.
FP Add TB ID tolerance to general Prod rules #39009wordingwordingEP, FP, HP throttle body inside dimensions must remain stock with +/-.25mm tolerance; butterfly dimensions stock in FP, HP only.
SRF3 Add HD Oil Cooler #38979otherotherSRF3 adds HD Oil Cooler P/N G1148500 as alternative to standard cooler P/N G480503.
FA Ligier JS F3 Tire Choice #38434tyres & wheelstyres & wheelsFA Ligier JS F3 front tires may be Hoosier 43363 240/580R13 MS, rear 43368 300/590R13 MS.
FP BMW Z4 update #38490inductionslowerEP BMW Z4 03-05 restricted to 52mm flat plate intake restrictor.
FP EP Fiat 124 Spider Competition Adjustment Request #38498weight -50 lbsfasterEP Fiat 124 Spider 1600 & 2000 weight drops 50 lbs to 2000; carburetors gain 2mm chokes to 36mm.
FP Base Weight Adjustment for H-Production X1/9 Spec Lines #38255weight -50 lbsfasterHP Fiat X-1/9 base weights reduced 50–53 lbs across 1300 and 1500 spec lines.
FP Request for Classification of Chevrolet Spark #37755cars addedcars addedChevrolet Spark 16-22 classified HP Pre at 1850 lbs minimum weight, fuel injected, 1399 cc.
FP Request to Lower Ford Festiva Minimum Weight to 1600 LBS #37939weight -100 lbsfasterHP Ford Festiva 88-93 minimum weight drops to 1600 lbs, variants to 1640 and 1680 lbs; compression ratio raised to 11.0:1.
SRF3 Driver Safety & Comfort #37966wordingwordingSRF drivers with disabilities may modify seat and controls for safety and comfort with approval and logbook notation.
FA Update Formula Renault 2.0 spec line notes #37853wordingwordingFA Formula Renault 2.0 (10-17) spec notes clarified: engine sealed, manual compliance required, tire choice unrestricted, no alterations except repairs.
FP Request Competition Adjustment to BMW Z3 2.5L #37120inductionslowerEP BMW Z3 and 3-series models get smaller intake restrictors: Z3 2.5L to 52mm, Z3 2.8L to 55mm, 328i to 58mm, 325i to 56mm.
FP FP Class Adjustments #37458inductionslowerFP Acura Integra and Honda Civic models get smaller 51mm intake restrictors, down from 55mm; Del Sol VTEC weight increases to 2290–2405 lbs.
FP Interpretation of Production Rules on Mirrors #37235wordingwordingEP, FP, HP: interior or exterior mirrors meeting rule 9.3.36 now permitted.
FP Weight Reduction for Honda S2000 #37466weightfasterEP Honda S2000 1997cc base loses 75 lbs to 2375; 2157cc base loses 60 lbs to 2450.
FP Mazda 1999 Miata 1.8L #37488weight -50 lbsfasterEP Mazda MX-5/Miata 99-05 minimum weight drops to 2100 lbs, 2153 lbs with power adder, 2205 lbs with two adders.
FP Errors & Omissions #37648cars addedcars addedFP GTL Volkswagen Jetta Mark IV 4dr FWD 98.2 wheelbase newly classified.
FP GTL/FP consolidation 2025 Rules #37659inductioninductionFP Spec Lines option: carburettor chokes permitted as alternative to SIR, same size as listed SIR.
Cal Club 2025 CALCL252025-02-22
1:39.542Greg Labadie · only car+24.954s (+33.46%)
1:39.898Greg Labadie · only car
127.4Greg Labadie
1:50.233Caleb Shrader · fastest of 33 · top 5 within 0.4s
1:50.825Caleb Shrader · fastest of 32 · top 5 within 0.8s
118.2John Black
+10.927squal +10.691s
110.9%qual 110.7%
1:56.121Michael Lewis · fastest of 5 · top 5 within 25.2s
1:55.440Michael Lewis · fastest of 6 · top 5 within 10.7s
110.9Michael Lewis
+15.542squal +16.579s
115.6%qual 116.7%
48 rule changes (FA: 4, SRF3: 14, FP: 30)9 weight · 8 cars added · 4 tyres & wheels · 3 induction · 2 engine · 2 suspension & brakes · 1 aero · 18 wording · 1 other · EP BMW Z3 2.5L requires 52mm flat plate intake restrictor; Z3 2.8L 55mm; 328i/is E36 58mm; 328i/ci E46 58mm; 325i/is E46 56mm; 325i/is E36 56mm; 325is M-Technic 56mm. · FA adds Tatuus F.3 T-318 or FR-19 as spec line car in Table 2 for Formula Regional European Championship. · EP BMW 325i/is E30 (84-91) weight reduced 50–52 lbs across three spec lines to 2150, 2204, 2258. · FP Spridget and Midget 1275cc and 1500cc spec line corrections to bore, stroke, displacement, and valve sizes. · F Production now allows GT-Lite cars meeting Appendix N specifications to compete, effective 2025-01-01. · HP Sprite and Midget 1275cc and 1098cc Level 2 compression ratio raised to 12.0:1. · FP Honda CRX/CRX Si 84-87 block material changes from Iron to Alum. · SRF3 air filter rule removes K&N RC-9160 option, leaving only P/N WM301020 allowed. · SRF brake rotor minimum thickness increases from 12.20mm to 13.25mm, Wilwood vented rotor P/N 800065. · SRF3 Hoosier logo placement changes from four decals to three decals in different locations. · SRF Hoosier decal requirement reduced from four decals in specific locations to three decals with simpler placement rules. · HP Volkswagen Golf and Jetta 85-92 track correction: front 1537mm (60.5in), rear 1529mm (60.2in). · SRF wet tires: P185/60R13 H20/W2 option removed; P185/65R13 W2 front now required with P205/60R13 W2 rear. · Nissan 300ZX 84-89 classified to EP at 2550 lbs minimum, 2960cc 6-cyl SOHC, fuel injection, 12.0:1 compression limit, 0.500" valve lift limit. · Mazda RX-7 92-97 newly classified EP Prep Level 2 at 2200–2310 lbs with 13B 6-port rotary engine. · EP Mazda RX-8 (04-11) alternate spec line removed; one primary line remains. · SRF3 alternator pulley minimum weight reduced from 12 oz to 11 oz. · FP Honda CRX 84-87 can replace plastic front header, rocker skirt, door cap panels with stock-appearance replicas in alternate materials. · FP Acura Integra and Honda Civic models now require 55mm Flat Plate Intake Restrictor. · HP removes four redundant VW spec lines: Rabbit Cabriolet 1780, Scirocco 1588, Scirocco 1780 8-valve, Scirocco 1588. · FP Mazda Protégé ES (01-03) model designation updated to include /5 variant. · HP Honda Civic 1.5 (88-91) weight reduced to 2175 lbs base, 2229 lbs with power adder, 2284 lbs with two. · FP Acura Integra LS and Honda Del Sol VTEC minimum weights increase 25–78 lbs across all configurations. · EP BMW Z3 2.5L weight increases to 2500 lbs, 2563 lbs with turbo, 2625 lbs with supercharger. · FP Honda throttle body specs corrected: Civic 1.5 to 42", Si to 55", CRX variants adjusted. · EP Mazda MX-5 1.8L 1990-97 minimum weight drops to 2150 lbs; 1994-97 variants to 2000, 2050, 2100 lbs respectively. · EP Triumph GT6 dual 1.75" carbs weight drops to 1940 lbs; triple Weber 40 DCOE options consolidated. · EP Honda S2000 fuel injected throttle body inside diameter increases from 62mm to 64mm. · EP Triumph TR8 dry sump allowance moved from carburetor line to notes section. · EP Porsche 944/924S 2.5L and 2.7L weight minimums corrected: 2479cc to 2306/2363 lbs, 2681cc to 2358/2415 lbs. · SRF rain/brake light now requires Super Bright LEDs Inc. P/N PT-STRB-R24 with specific connector and rain light switch. · SRF requires Super Bright LEDs P/N PT-STRB-R24 rain/brake light with strobing capability and specific wiring. · SRF adds brake duct and pedal extension rules, rear shift cable clamp option, camber limit to 5.0°, radiator opening height 3.5" ±0.5", and P2 engine restrictor changes. · EP Porsche 944/924S combines 2.5L and 2.7L variants with new weights: 2250–2415 lbs depending on engine and year. · FP Toyota Corolla 2TC loses 43 lbs to 1810; HP Corolla loses 50–52 lbs to 1910–2006. · EP Triumph GT6 minimum weight reduced to 1800 lbs. · SRF radiator rule clarified: P/N 480466 replaceable with Automotive P/N 1R698, CU698 or manufacturer equivalent with documentation. · FP and HP Sprite, Midget, and Spitfire 1500 intake valve size corrected to 36.6/(1.44). · HP Volkswagen Rabbit Cabriolet 1780 removed; Rabbit 1588 and 1715 reclassified with engine sizes and year ranges specified. · FA Pro Formula Mazda front wheels widen to 10 in. max; rear wheels narrow to 14 in. min. · Ford Fiesta HP and Chevrolet Sonic FP model year ranges extended from 2016 to 2019. · SRF Hoosier wet front tire updated to P/N 46100 P185/60R13 H20 or W2. · 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. · 1978-80 Toyota Celica classified FP Prep Level 2, 2100-2205 lbs, 2190cc SOHC, 11.0:1 compression, .450" valve lift max. · SRF Hoosier front rain tyre part number changes from 46100 to 46101 P185/65R13 W2. · SRF Renault Alliance solid front rotors banned; restrictor reduced 35mm to 34mm for 2011+ Kawasaki; minimum weight increased to 1100 lbs for 2009+ stock engines. · SRF3 tail sections allowed on SRFs with GEN3 airbox shimming up to 19 mm; alternate dash panel P/N 180100 or 180101 relocated in rules.showhide
FP Effective date for Jan 2025 GCR updates #37654inductionslowerEP BMW Z3 2.5L requires 52mm flat plate intake restrictor; Z3 2.8L 55mm; 328i/is E36 58mm; 328i/ci E46 58mm; 325i/is E46 56mm; 325i/is E36 56mm; 325is M-Technic 56mm.
FA Classify FR European Championship car as spec line car in Table 2 #37658cars addedcars addedFA adds Tatuus F.3 T-318 or FR-19 as spec line car in Table 2 for Formula Regional European Championship.
FP Request to Reduce Weight of BMW 325i/is E30 (84-91) Spec Line #37119weight -50 lbsfasterEP BMW 325i/is E30 (84-91) weight reduced 50–52 lbs across three spec lines to 2150, 2204, 2258.
FP Fix Error in Spridget Spec Line #37437wordingwordingFP Spridget and Midget 1275cc and 1500cc spec line corrections to bore, stroke, displacement, and valve sizes.
FP Create ruleset that allows GTL cars to run in FP #37485cars addedcars addedF Production now allows GT-Lite cars meeting Appendix N specifications to compete, effective 2025-01-01.
FP 1275 HP Spridget Level 2 Only #36518enginefasterHP Sprite and Midget 1275cc and 1098cc Level 2 compression ratio raised to 12.0:1.
FP Errors/emissions Honda Civic/CRX #36700enginefasterFP Honda CRX/CRX Si 84-87 block material changes from Iron to Alum.
SRF3 Update SRF3 Air Filter Rule #36681wordingunclearSRF3 air filter rule removes K&N RC-9160 option, leaving only P/N WM301020 allowed.
SRF3 Hoosier Tire Decal Placement #36739wordingwordingSRF3 Hoosier logo placement changes from four decals to three decals in different locations.
SRF3 Update to Letter 36619 with new Hoosier Contingency Decal Info #36624wordingwordingSRF Hoosier decal requirement reduced from four decals in specific locations to three decals with simpler placement rules.
FP Errant entry in HP production line item #36231wordingwordingHP Volkswagen Golf and Jetta 85-92 track correction: front 1537mm (60.5in), rear 1529mm (60.2in).
SRF3 Update Rain Tire Rule and Hoosier Decal Placement #36436tyres & wheelsslowerSRF wet tires: P185/60R13 H20/W2 option removed; P185/65R13 W2 front now required with P205/60R13 W2 rear.
FP NIssan 300ZX Z31 to EP #35830cars addedcars addedNissan 300ZX 84-89 classified to EP at 2550 lbs minimum, 2960cc 6-cyl SOHC, fuel injection, 12.0:1 compression limit, 0.500" valve lift limit.
FP RX7 1993 and Up Request In EP Spec Lines, classify #36031cars addedcars addedMazda RX-7 92-97 newly classified EP Prep Level 2 at 2200–2310 lbs with 13B 6-port rotary engine.
FP Clean-up Multiple EP RX-8 Spec Lines In EP #36156wordingwordingEP Mazda RX-8 (04-11) alternate spec line removed; one primary line remains.
SRF3 SRF3 Alternator Pulley Update In #36095weightfasterSRF3 alternator pulley minimum weight reduced from 12 oz to 11 oz.
FP Request to Replace CRX Plastic Panels #35876wordingwordingFP Honda CRX 84-87 can replace plastic front header, rocker skirt, door cap panels with stock-appearance replicas in alternate materials.
FP FP data and parity #35896inductionslowerFP Acura Integra and Honda Civic models now require 55mm Flat Plate Intake Restrictor.
FP Update FP Protege (01-03) Model Info #35715wordingwordingFP Mazda Protégé ES (01-03) model designation updated to include /5 variant.
FP Update 1988-1991 Civic to Match 1988-1991 CRX #35399weightfasterHP Honda Civic 1.5 (88-91) weight reduced to 2175 lbs base, 2229 lbs with power adder, 2284 lbs with two.
FP FP data #35060weight +25 lbsslowerFP Acura Integra LS and Honda Del Sol VTEC minimum weights increase 25–78 lbs across all configurations.
FP Request to Review Z3 2.5 Spec Line #35073weight +50 lbsslowerEP BMW Z3 2.5L weight increases to 2500 lbs, 2563 lbs with turbo, 2625 lbs with supercharger.
FP Corrections to Honda Spec Lines in FP #35250wordingunclearFP Honda throttle body specs corrected: Civic 1.5 to 42", Si to 55", CRX variants adjusted.
FP Miata Alternate Head #35253weight -50 lbsfasterEP Mazda MX-5 1.8L 1990-97 minimum weight drops to 2150 lbs; 1994-97 variants to 2000, 2050, 2100 lbs respectively.
FP Honda S2000 throttle body #35272inductionfasterEP Honda S2000 fuel injected throttle body inside diameter increases from 62mm to 64mm.
FP Correction within Triumph TR8 Spec Line #35315wordingwordingEP Triumph TR8 dry sump allowance moved from carburetor line to notes section.
FP Correction to EP 924S/944 Spec Line #35317wordingwordingEP Porsche 944/924S 2.5L and 2.7L weight minimums corrected: 2479cc to 2306/2363 lbs, 2681cc to 2358/2415 lbs.
SRF3 Update SRF Rain / Brake Rule #34706wordingwordingSRF rain/brake light now requires Super Bright LEDs Inc. P/N PT-STRB-R24 with specific connector and rain light switch.
SRF3 Update SRF Brake Light Rule v1 #34853wordingwordingSRF requires Super Bright LEDs P/N PT-STRB-R24 rain/brake light with strobing capability and specific wiring.
SRF3 SRF Radiator Rule Update #34805wordingwordingSRF radiator rule clarified: P/N 480466 replaceable with Automotive P/N 1R698, CU698 or manufacturer equivalent with documentation.
FP Correct Intake Valve Size on 1500cc Midget/Spitfire #34419wordingwordingFP and HP Sprite, Midget, and Spitfire 1500 intake valve size corrected to 36.6/(1.44).
FP ITC to FP? #34286cars addedcars addedHP Volkswagen Rabbit Cabriolet 1780 removed; Rabbit 1588 and 1715 reclassified with engine sizes and year ranges specified.
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.
FP Request to Classify Sonic and Fiesta in HP #34264wordingwordingFord Fiesta HP and Chevrolet Sonic FP model year ranges extended from 2016 to 2019.
SRF3 Hoosier SRF Wet Front Tire Rule Update #34189tyres & wheelsunclearSRF Hoosier wet front tire updated to P/N 46100 P185/60R13 H20 or W2.
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 addedcars addedFA MSR Formula Mazda FMzR added to Table 2 classification.
FP Classification Request for 1978 Toyota Celica #34097cars addedcars added1978-80 Toyota Celica classified FP Prep Level 2, 2100-2205 lbs, 2190cc SOHC, 11.0:1 compression, .450" valve lift max.
SRF3 Update SRF Front W2 Rain Tire Part Number #34118tyres & wheelstyres & wheelsSRF Hoosier front rain tyre part number changes from 46100 to 46101 P185/65R13 W2.
SRF3 Update SRF Brake Rule #33469suspension & brakesslowerSRF Renault Alliance solid front rotors banned; restrictor reduced 35mm to 34mm for 2011+ Kawasaki; minimum weight increased to 1100 lbs for 2009+ stock engines.
SRF3 Update SRF Bodywork Fitment Rule #33765wordingwordingSRF3 tail sections allowed on SRFs with GEN3 airbox shimming up to 19 mm; alternate dash panel P/N 180100 or 180101 relocated in rules.
Cal Club 2023 CALCL232023-02-24
1:14.588Greg Labadie · only car
150 earlier rule changes on record, in force before Cal Club 2023 (from 2019)28 cars added · 16 weight · 11 induction · 9 engine · 6 suspension & brakes · 5 tyres & wheels · 1 aero · 1 removed · 73 wording · FP Mazda Protégé ES (01-03) renamed to include P5 designation as Mazda Protégé ES/5 (01-03). · FA BDA engine displacement specification line added to Table 1, effective 2023-01-01. · EP, FP, HP cylinder head ports limited to 1 inch maximum depth matching from mating surface. · 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. · VW New Beetle 2.5L 5-cyl added to EP at 2400–2520 lbs, 2480 cc, fuel injection, comp ratio 12.0:1 max, valve lift 0.500" max. · EP Mazda RX-7 12A/13B gains fuel injection option on dual-y manifold with 42mm choke(s). · EP VW Corrado 92-95 stroke corrected to 90.3 mm, displacement to 2792 cc. · EP Subaru BRZ and Toyota 86/Scion FR-S model year ranges updated to 13-20. · SRF tire rule wording changed from 'Tires: must be run as delivered' to 'Tires must be run as delivered.' · SRF brake rotor minimum thickness reduced from 13.25 to 12.20mm; seal and air filter rules clarified. · 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. · FP Lotus Super Seven 91.7 ci minimum weight increases to 1580 lbs. · EP Mazda MX-5 Global Cup 16-22 minimum weight set to 2400 lbs; sequential gearbox allowed with +150 lbs penalty. · BMW 128i (08-13) classified in EP at 2700 lbs minimum with stock throttle body, 11.0:1 compression ratio, 0.400 in. valve lift limits. · EP/FP/HP open cars may now use carbon fiber hardtops if they retain OEM appearance in all exterior profiles. · Mazda Protégé ES 99-00 classified in FP at 2150–2258 lbs with 1839cc DOHC engine, fuel injection, 11.0:1 compression, .450" valve lift limit. · 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. · EP Mazda RX-8 13B carburetor rules clarified: dual 2bbl carb, fuel injected throttle body, or stock fuel injection permitted. · EP and FP Production clarifies idle control valve rules: stock devices allowed original, removed with blocked ports, or mechanical replaced with electronic stock type. · FP BMW 325e/es displacement corrected from 1647 to 2693 cc. · FA Pro Formula Mazda now allows street port or bridge port, previously porting was prohibited. · EP BMW Z3 2.5L intake restrictor reduced from 59mm to 58mm flat plate. · Ford Mustang 99-03 classified to EP at 2700/2768/2835 lbs; 94-98 Mustang weight reduced to 2550/2614/2678 lbs. · EP, FP, HP Improved Touring cars may use any DOT-approved tire per section 9.3.45 in Production class. · FP VW Golf III/Jetta III 93-98 intake valve to 39.5/1.56, exhaust to 32.9/1.30. · 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. · EP, FP, HP classes allow stock/original idle control devices unmodified or completely removed with openings blocked. · EP Porsche 968 intake valve size increased from 37 to 39.0 mm. · EP, FP, HP front-wheel-drive cars may alter body and suspension to install alternate transmission, transaxle, and axle shaft. · EP BMW Z3 2.5L allows alternate throttle body from 92-95 325i with Turner adapter; head casting 1738400 permitted with specific blocks. · FP Honda Civic Del Sol VTEC removes restrictions on dry sump, connecting rods, intake manifold porting, crankshaft, rocker arms, cam followers. · FP Honda Prelude 84-87 and Mazda GLC/323 86-88 standardize valve lift measurement and remove Level 1 dry sump restrictions. · EP Porsche 944S2 89-91 requires 56mm flat plate intake restrictor; comp ratio max 12.0:1, valve lift max 0.500". · HP Corolla GTS RWD (84-87) added at 2300 lbs; HP Corolla FX16 FWD (87-88) added at 2260 lbs; old Corolla (84-87) removed. · SRF front wet tire changes from P185/60R13 H20 to P185/65R13 W2; SRF3 adds mandatory G301048 restrictor plate Jan. 1, 2022. · HP Toyota MR-2 1.6L (85-89) track corrected to 15.47 inches front and rear. · FA Mazda MZR 2.0 spec line removes redundant '2.0' designation; Honda Civic K20Z3 spec line unchanged. · 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. · Honda S2000 (00-03) reclassified as EP Prep with F22c engine option: 1997cc or 2157cc, weight 2450–2636 lbs depending on displacement. · EP Nissan 240-SX S13/S14 loses 200-210 lbs minimum weight; comp ratio rises to 12.0:1, valve lift to .500. · SRF wet tyres add Hoosier P185/60R13 W2 front and P205/60R13 W2 rear as alternatives to H20. · SRF adds SADEV-SRF3 6-speed sequential option with final drive 3.20 versus OEM 5-speed 3.85. · SRF seal procedures clarified: unsealed components need CSR inspection and logbook notation instead of engine removal. · 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. · EP Lotus/Caterham 7 America carburetor changed from IT fuel injection prep to fuel injection. · Plymouth Arrow 1598cc four-cylinder classified to HP at 1800 lbs minimum weight. · BMW 318i E30 (84-85) reclassified from FP to HP at 2200–2310 lbs with fuel injection and .425" valve lift limit. · FP Fiat X-1/9 1300 loses 50 lbs to 1665; X-1/9 loses 50 lbs to 1765. · Daimler SP 250 classified in EP at 2165 lbs with 2548 cc OHV 8-cylinder engine. · FA Mazda MZR 2.0 limited to Ralt RT40, RT41, Swift 008, 014 chassis; Honda Civic K20Z3 removes Swift 016 chassis. · Porsche 924 moves from EP to FP Level 1 Prep, classified at 2200 lbs with 1984cc 4-cylinder OHC engine. · EP, FP, HP clarifies percentage weight penalties sum first, then apply to base weight, rounding to nearest pound. · SRF3 alternator pulley restricted to P/N G902130 or G902130A, 12oz minimum weight. · 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. · 84-87 Mazda 626 reclassified from FP to HP with 2300–2415 lbs weight, 1998cc SOHC, dual 32mm carbs. · FP Fiat X1/9 brake rotors change to 257 (10.1) x 12 (.407) solid disc. · 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. · Mazda 3 S 04-08 classified in EP at 2350 lbs minimum, 2.26L DOHC, 12.0:1 compression, .500" valve lift limit. · FP Volkswagen Golf III and IV intake valves increase to 40.0 mm, exhaust valves to 33.0 mm. · 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. · SRF and SRF3 mandatory identification simplified: removed Ford Performance and Blue Oval decals, kept Hoosier logo placement. · Formula Lites Crawford FL15 newly classified in FA. · EP Austin-Healey 3000 Mk. I, II, III now allows TR-6 front calipers and discs as alternate. · FP Volkswagen Golf 1.8 (85-92), Jetta 1.8 (85-92) lose 50 lbs to 1900; Jetta (82-84), Rabbit, Scirocco lose 50-100 lbs to 1733-1803. · FP Volkswagen Golf and Jetta 1.8 lose 50 lbs each, to 1900. HP Jetta GLI engine code removed. · EP, FP, HP Level 1 and Level 2 induction systems: clarified carburetor and fuel injection rules, jets/needles/rods unrestricted in Level 2. · EP Datsun SRL 311U Roadster minimum weight reduced to 1925 lbs from 2000 lbs. · EP Triumph TR8 78-81 weight reduced from 2600 to 2500 lbs. · Honda Civic EX 96-00 classified in FP at 1975 lbs, 1590cc SOHC, 56mm throttle body, valve lift .450" max. · FP adds FAJS carburetor to permitted Weber and auto-type substitutions in two rule sections. · SRF shocks, springs, bump stops sealed; rear springs 412-429 lbs/in P/N 280390 only; previous parts no longer allowed. · HP 84-87 Toyota Corolla wheel diameter increases from 13 to 15 inches. · EP BMW Z3 2.5L iron block casting 1738566-C designation removed, wording clarification only. · FA stock engines not given weight adjustment; modified engines now allowed in class. · Porsche 911 S 67-68 classified in EP at three weight levels: 1800, 1845, or 1890 lbs. · FP Mazda 626 84-87 carburetor spec now specifies two auto-type sidedraft 32mm choke carbs or fuel injection. · 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. · EP BMW 2.8L, 328i E36/E46, and 325i E36 blocks now iron only; 325i E46 aluminum only. · FP Volkswagen Scirocco E&O adds four engine variants with weights 1520–1853 lbs and displacements 1471–1780 cc. · SRF3 shock absorber brand restriction removed; all shocks must be sealed by Enterprises. · FA Volkswagen 1835cc SOHC removed from Table 1. · FA engine rules clarified: blocks and heads must be OEM unless Tables note exceptions. · 1990-1994 Mazda Protege classified in FP Pre at 2150–2258 lbs with 1839cc DOHC engine, fuel injection. · HP Mini Cooper model year ranges for convertibles revised: 02-06 now includes 05-08, 07-13 now includes 09-15. · SRF3 bump stop now must be SCCA P/N 280407 only, no modifications, optional, max one per shock. · SRF shock absorber bump stop clarified: only SCCA P/N 280407 allowed as delivered, maximum one per shock, effective 05/01/2020. · 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. · EP Caterham 7 Spec Line removes redundant suspension note, clarifies engine prep limits and comp ratio to 10.0:1. · 1989-90 Nissan 240-SX SOHC added to FP Level 2 with 2400-2520 lbs weight range. · FA engine note clarification removes Table E reference, Pro Formula Mazda directed to Table 1. · FP Volkswagen Jetta, Rabbit, Scirocco 1457-1853cc reclassified with inlet valve 40.0mm, exhaust 33.0mm, weights 1520-1853 lbs. · HP Datsun 510 gains 40 DCOE carburetor option alongside existing 40 DCN and 36mm DCNVH choices. · Porsche 914-4 2.0L classified in FP Prep 2 at 2030-2132 lbs with 1968cc OHV engine, 11.0:1 compression limit, .450" valve lift limit. · FP Ford Fiesta 78-80 weight reduced 130 lbs to 1660. · HP Datsun 1200 carburetor choke size increases from 26mm to 30mm. · 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. · FP and EP Mazda Miata models standardized to 55mm throttle body diameter; brake spec clarified. · FP Mazda Protégé ES 01-03 newly classified at 2350–2468 lbs with 1991cc 4-cyl DOHC, fuel injection, 11.0:1 compression, .450 in. valve lift limit. · SRF rain and brake rule wording updated; supersedes GCR 9.3.32.B.2 effective 1/1/202 through 12/31/2024. · 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. · FP and HP Honda Civic and CRX 1988–91 track specifications corrected to 61.3/61.7 inches. · EP, FP, HP cylinder head rules reorganized for clarity; no performance change. · SRF bans tire warmers and cooling methods other than natural air convection or conduction. · SRF front nose weight minimum reduced from 35 to 32 lbs. · SRF3 reclassified as Spec Racer Ford 3 with 1.6L conversion; SRF2 becomes Regional Only Class. · 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. · FA Swift 014 Mazda MZR 2.0 piston minimum weight reduced from 320g to 280g. · FP and HP Austin-Healey Sprite Mk I and MG Midget variants may replace rear bodywork aft of cockpit with stock-appearing alternate material components. · EP Mazda MX-5 Global Cup classification year changes from 16-18 to 16-19. · Production suspension rule clarifies spindles, hubs, bushings, bearings, ball joints unrestricted. · Production carb rules clarified: carburetor options, fuel injection throttle body dimensions, and intake manifold restrictions reorganised and refined. · EP, FP, HP carburetors clarified: jets, needles, metering rods, needle valves unrestricted; choke parts removable; permitted optional carburetors listed. · EP Mazda MX-5/Miata eligibility years expanded from 1999-2002 to 1999-2005. · SRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102. · FA Line N minimum weight increases to 1375 lbs. · SRF3 nose assembly must use approved multi-piece design; no modifications allowed except as specified. · FA cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs. · SRF3 brakes now allow Hawk Blue 9012 pads P/N 801993 only; shocks simplified to Penske P/N 280396 sealed assembly only, with optional SCCA Enterprises bump rubber P/N 280407 from 05/01/2020. · EP, FP, HP clarified: tapered holes in ball joints now allowed for bolt conversion; wheel bearings and hubs unrestricted at any wheel. · EP open cars may now use aftermarket hardtops if they retain OEM appearance; specific model hardtop allowances removed. · FA Formula 3 car sequential gearbox weight penalty of 25 lbs removed; minimum weight now 1215 lbs. · FP Dodge Daytona/Chrysler Laser added at 2100/2153/2205 lbs; Shelby Charger/Omni 024 weight reduced to 2100/2153/2205 lbs. · 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.showhide
FP Request to Add Mazda Protege P5 to FP #33664wordingwordingFP Mazda Protégé ES (01-03) renamed to include P5 designation as Mazda Protégé ES/5 (01-03).
FA BDA Displacement #33431wordingwordingFA BDA engine displacement specification line added to Table 1, effective 2023-01-01.
FP Review Limited Prep Port Matching Rules #33600wordingwordingEP, FP, HP cylinder head ports limited to 1 inch maximum depth matching from mating surface.
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 #33160wordingwordingPro Formula Mazda allows street or bridge port, unrestricted apex seals, 70mm throttle body, 99cm wing height max, 132cm bodywork width max.
FP Request to classify VW New Beetle 2.5L in EP #32725cars addedcars addedVW New Beetle 2.5L 5-cyl added to EP at 2400–2520 lbs, 2480 cc, fuel injection, comp ratio 12.0:1 max, valve lift 0.500" max.
FP Request Rotary Injection on Dual Y manifold #32775inductionunclearEP Mazda RX-7 12A/13B gains fuel injection option on dual-y manifold with 42mm choke(s).
FP Request for Corrado Stroke & Displacement Correction #32985wordingwordingEP VW Corrado 92-95 stroke corrected to 90.3 mm, displacement to 2792 cc.
FP Subaru BRZ Model Years #32500wordingwordingEP Subaru BRZ and Toyota 86/Scion FR-S model year ranges updated to 13-20.
SRF3 SRF Tire Rule Update #32614wordingwordingSRF tire rule wording changed from 'Tires: must be run as delivered' to 'Tires must be run as delivered.'
SRF3 Brake, seal, and air filter clarifications #32670suspension & brakesfasterSRF brake rotor minimum thickness reduced from 13.25 to 12.20mm; seal and air filter rules clarified.
FA Update FR Americas rulebook requirement #32491wordingwordingFA 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 #32522wordingwordingFA sealed engines must undergo full inspection; competitor pays reassembly and resealing costs.
FA Clarify Formula Lites and FR Americas sealed engine requirement #32523wordingwordingFA Formula Lites FL15 and FR Americas Ligier JS F3 engine sealing requirements clarified to reference respective series technical regulations.
FP Weight Adjustment of Lotus 7 #32213weight +50 lbsslowerFP Lotus Super Seven 91.7 ci minimum weight increases to 1580 lbs.
FP EP MX-5 Global Cup Car #32218weightslowerEP Mazda MX-5 Global Cup 16-22 minimum weight set to 2400 lbs; sequential gearbox allowed with +150 lbs penalty.
FP Please Class BMW 128i in EP #32370cars addedcars addedBMW 128i (08-13) classified in EP at 2700 lbs minimum with stock throttle body, 11.0:1 compression ratio, 0.400 in. valve lift limits.
FP Inconsistency in Body Work Descriptions #32396aerofasterEP/FP/HP open cars may now use carbon fiber hardtops if they retain OEM appearance in all exterior profiles.
FP Request to classify the 1999-2000 Mazda Protege in FP #32398cars addedcars addedMazda Protégé ES 99-00 classified in FP at 2150–2258 lbs with 1839cc DOHC engine, fuel injection, 11.0:1 compression, .450" valve lift limit.
FA E&O FA Transmission section #32251wordingwordingFA 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.
FP Request Idle control valve clarification #32178wordingwordingEP and FP Production clarifies idle control valve rules: stock devices allowed original, removed with blocked ports, or mechanical replaced with electronic stock type.
FP Correct FP BMW 325e/es Displacement #32394wordingwordingFP BMW 325e/es displacement corrected from 1647 to 2693 cc.
FA Closing the Gap #31934inductionfasterFA Pro Formula Mazda now allows street port or bridge port, previously porting was prohibited.
FP EP Adjustments #31858inductionslowerEP BMW Z3 2.5L intake restrictor reduced from 59mm to 58mm flat plate.
FP 1999 3.8L Ford Mustang to EP? #31635weightfasterFord Mustang 99-03 classified to EP at 2700/2768/2835 lbs; 94-98 Mustang weight reduced to 2550/2614/2678 lbs.
FP Improved Touring Tires #32064tyres & wheelstyres & wheelsEP, FP, HP Improved Touring cars may use any DOT-approved tire per section 9.3.45 in Production class.
FP VW Golf Jetta 2.0L intake and exhaust size correction. #32173inductionslowerFP VW Golf III/Jetta III 93-98 intake valve to 39.5/1.56, exhaust to 32.9/1.30.
FA Reorganize Tables 1 and 2 #31985cars addedcars addedFA adds Honda K20Z3 2.0L engine spec at 1350 lbs minimum and Mazda MZR 2.0L spec at 1300 lbs minimum to Table 1.
FP Throttle Body and Idle Air #31800wordingwordingEP, FP, HP classes allow stock/original idle control devices unmodified or completely removed with openings blocked.
FP Porsche 968 Engine Questions #31478enginefasterEP Porsche 968 intake valve size increased from 37 to 39.0 mm.
FP PCS E. 2. n. 4. Add Axle Shaft to Allow FWD the Same Freedom #31592wordingwordingEP, FP, HP front-wheel-drive cars may alter body and suspension to install alternate transmission, transaxle, and axle shaft.
FP BMW Z3 2.5L Spec Line #31724wordingwordingEP BMW Z3 2.5L allows alternate throttle body from 92-95 325i with Turner adapter; head casting 1738400 permitted with specific blocks.
FP FP Del Sol VTEC #31859enginefasterFP Honda Civic Del Sol VTEC removes restrictions on dry sump, connecting rods, intake manifold porting, crankshaft, rocker arms, cam followers.
FP Standardize Level 2 Classifications in FP #31868wordingwordingFP Honda Prelude 84-87 and Mazda GLC/323 86-88 standardize valve lift measurement and remove Level 1 dry sump restrictions.
FP 944S2 Restrictor #31396inductionslowerEP Porsche 944S2 89-91 requires 56mm flat plate intake restrictor; comp ratio max 12.0:1, valve lift max 0.500".
FP Classing Clarification for 1986 Toyota Corolla FX16 #31527cars addedcars addedHP Corolla GTS RWD (84-87) added at 2300 lbs; HP Corolla FX16 FWD (87-88) added at 2260 lbs; old Corolla (84-87) removed.
SRF3 Three Updates to SRF Rules #31523tyres & wheelsunclearSRF front wet tire changes from P185/60R13 H20 to P185/65R13 W2; SRF3 adds mandatory G301048 restrictor plate Jan. 1, 2022.
FP E&O; MR2 Track #31120wordingwordingHP Toyota MR-2 1.6L (85-89) track corrected to 15.47 inches front and rear.
FA E&O Table 2 engine names #31085wordingwordingFA Mazda MZR 2.0 spec line removes redundant '2.0' designation; Honda Civic K20Z3 spec line unchanged.
FA Move Toyota 1800 to Table 2 #30822cars addedcars addedFA Toyota 1800 moves from Table 1 to Table 2 (Spec Line Cars).
FA E&O Swift 016 wheel width reference #30939wordingwordingFA Swift 016 Mazda MZR/Ford Duratec wheel width specification clarified: front 10, rear 14 minimum and 15 maximum.
FP Request to Allow F22c Engine for 2000-2003 Honda S2000 #30548cars addedunclearHonda S2000 (00-03) reclassified as EP Prep with F22c engine option: 1997cc or 2157cc, weight 2450–2636 lbs depending on displacement.
FP Request a review of the S14 240SX in EP. #30873weight -200 lbsfasterEP Nissan 240-SX S13/S14 loses 200-210 lbs minimum weight; comp ratio rises to 12.0:1, valve lift to .500.
SRF3 SRF Wet Tires #30849tyres & wheelstyres & wheelsSRF wet tyres add Hoosier P185/60R13 W2 front and P205/60R13 W2 rear as alternatives to H20.
SRF3 SADEV-SRF3 Transmission #30926cars addedunclearSRF adds SADEV-SRF3 6-speed sequential option with final drive 3.20 versus OEM 5-speed 3.85.
SRF3 SRF Update Maintenance, Repairs and Seals #30961wordingwordingSRF seal procedures clarified: unsealed components need CSR inspection and logbook notation instead of engine removal.
FA Update FA rules package #30717wordingwordingFA 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 #30718wordingwordingFA 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 #30719wordingwordingFA Mazda MZR 2.0 and Honda Civic K20Z3 remove sequential designation from 5-speed transmission spec.
FP Lotus/Caterham 7 America Request #30392wordingunclearEP Lotus/Caterham 7 America carburetor changed from IT fuel injection prep to fuel injection.
FP Request to classify ITC Plymouth Arrow #30588cars addedcars addedPlymouth Arrow 1598cc four-cylinder classified to HP at 1800 lbs minimum weight.
FP Reclassification of the 1984/85 BMW 318i from FP to HP #30661cars addedcars addedBMW 318i E30 (84-85) reclassified from FP to HP at 2200–2310 lbs with fuel injection and .425" valve lift limit.
FP Fiat x1/9 Competition Adjustments #30711weight -50 lbsfasterFP Fiat X-1/9 1300 loses 50 lbs to 1665; X-1/9 loses 50 lbs to 1765.
FP Reclassify Daimler SP 250 #30721cars addedcars addedDaimler SP 250 classified in EP at 2165 lbs with 2548 cc OHV 8-cylinder engine.
FA E&O Mazda MZR 2.0 and Honda Civic K20Z3 chassis eligibility #30632wordingwordingFA Mazda MZR 2.0 limited to Ralt RT40, RT41, Swift 008, 014 chassis; Honda Civic K20Z3 removes Swift 016 chassis.
FP Move Porsche 924 in Level 1 Prep From EP to FP #30135cars addedcars addedPorsche 924 moves from EP to FP Level 1 Prep, classified at 2200 lbs with 1984cc 4-cylinder OHC engine.
FP Clarify Application of Percentage Based Weight Penalties #30669weightslowerEP, FP, HP clarifies percentage weight penalties sum first, then apply to base weight, rounding to nearest pound.
SRF3 SRF3 Alternator Pulley #30684engineslowerSRF3 alternator pulley restricted to P/N G902130 or G902130A, 12oz minimum weight.
FA Correct engine name in Swift 016 2.3 liter spec line #30447wordingwordingFA 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 #30448wordingwordingFA 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.
FP Change Classification of 84-87 Mazda 626 from FP to HP #30350cars addedcars added84-87 Mazda 626 reclassified from FP to HP with 2300–2415 lbs weight, 1998cc SOHC, dual 32mm carbs.
FP Fiat X1/9 brake rotors #30423suspension & brakessuspension & brakesFP Fiat X1/9 brake rotors change to 257 (10.1) x 12 (.407) solid disc.
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 #30369wordingwordingFA Ligier JS F3 car name corrected in FR Americas spec line.
FA Clean up Spec Line D in Table 1 #30372wordingwordingFA 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.
FP Please Classify Mazda3 in FP #30165cars addedcars addedMazda 3 S 04-08 classified in EP at 2350 lbs minimum, 2.26L DOHC, 12.0:1 compression, .500" valve lift limit.
FP Golf MkIII Valve Size Request #30268enginefasterFP Volkswagen Golf III and IV intake valves increase to 40.0 mm, exhaust valves to 33.0 mm.
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 #30274wordingwordingFA 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 #30276wordingwordingFA 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 #30278wordingwordingFA 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.
SRF3 Mandatory identification: #30223wordingwordingSRF and SRF3 mandatory identification simplified: removed Ford Performance and Blue Oval decals, kept Hoosier logo placement.
FA Request to classify Formula Lites Crawford FL15 #29702cars addedcars addedFormula Lites Crawford FL15 newly classified in FA.
FP Alternate Front Brake Rotors and Calipers for EP AH 3000 #29893suspension & brakessuspension & brakesEP Austin-Healey 3000 Mk. I, II, III now allows TR-6 front calipers and discs as alternate.
FP Mk2 VW Consistency and Cleanup of FP and HP Spec Lines #29195weight -50 lbsfasterFP Volkswagen Golf and Jetta 1.8 lose 50 lbs each, to 1900. HP Jetta GLI engine code removed.
FP Correct Wording for Level 1 and Level 2 Induction Systems #29406wordingwordingEP, FP, HP Level 1 and Level 2 induction systems: clarified carburetor and fuel injection rules, jets/needles/rods unrestricted in Level 2.
FP Weight Reduction for Datsun Roadster #29409weight -75 lbsfasterEP Datsun SRL 311U Roadster minimum weight reduced to 1925 lbs from 2000 lbs.
FP EP TR8 Adjustment #29512weight -100 lbsfasterEP Triumph TR8 78-81 weight reduced from 2600 to 2500 lbs.
FP Request to Classify 1996-2000 Honda Civic EX #29515cars addedcars addedHonda Civic EX 96-00 classified in FP at 1975 lbs, 1590cc SOHC, 56mm throttle body, valve lift .450" max.
FP FAJS Carburetor #29576wordingwordingFP adds FAJS carburetor to permitted Weber and auto-type substitutions in two rule sections.
SRF3 SRF Shocks, Springs and Ride Height. #29688suspension & brakessuspension & brakesSRF shocks, springs, bump stops sealed; rear springs 412-429 lbs/in P/N 280390 only; previous parts no longer allowed.
FP 84-87 Toyota Corolla HP Wheel Diameter Allowance Proposal E&O #29458tyres & wheelsfasterHP 84-87 Toyota Corolla wheel diameter increases from 13 to 15 inches.
FP EP BMW Z3 Rule Clarification #28998wordingwordingEP BMW Z3 2.5L iron block casting 1738566-C designation removed, wording clarification only.
FA Request to Adjust FB Weight for Stock Engines #29005wordingwordingFA stock engines not given weight adjustment; modified engines now allowed in class.
FP Request to Classify Porsche 911 2.0L #28456cars addedcars addedPorsche 911 S 67-68 classified in EP at three weight levels: 1800, 1845, or 1890 lbs.
FP Request to change to Carburetor Spec Line 84-87 Mazda 626 #28926wordingunclearFP Mazda 626 84-87 carburetor spec now specifies two auto-type sidedraft 32mm choke carbs or fuel injection.
FA E&O permitted engine modifications #28831wordingwordingFA 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 #28832wordingwordingFA 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 #28884wordingwordingFA Swift 016 Mazda Duratec Gurney flap wording clarified; terminology and mounting rules unchanged.
FP BMW Cylinder Head Casting and Part Numbers #28708engineslowerEP BMW 2.8L, 328i E36/E46, and 325i E36 blocks now iron only; 325i E46 aluminum only.
FP Correct Scirocco Spec line E&O #28892cars addedcars addedFP Volkswagen Scirocco E&O adds four engine variants with weights 1520–1853 lbs and displacements 1471–1780 cc.
SRF3 SRF Shocks #28791wordingwordingSRF3 shock absorber brand restriction removed; all shocks must be sealed by Enterprises.
FA Remove redundant spec line in Table 1 #28720removedremovedFA Volkswagen 1835cc SOHC removed from Table 1.
FA E&O general engine rules #28772wordingwordingFA engine rules clarified: blocks and heads must be OEM unless Tables note exceptions.
FP Request to Classify 1990-1994 Mazda Protege #28381cars addedcars added1990-1994 Mazda Protege classified in FP Pre at 2150–2258 lbs with 1839cc DOHC engine, fuel injection.
FP Error in Mini Cooper Spec Line #28713wordingwordingHP Mini Cooper model year ranges for convertibles revised: 02-06 now includes 05-08, 07-13 now includes 09-15.
SRF3 Update Bump Stop Rule #28712suspension & brakessuspension & brakesSRF3 bump stop now must be SCCA P/N 280407 only, no modifications, optional, max one per shock.
SRF3 SRF Bump Stop Correction #27019wordingwordingSRF shock absorber bump stop clarified: only SCCA P/N 280407 allowed as delivered, maximum one per shock, effective 05/01/2020.
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 #28554wordingwordingFA 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.
FP Caterham 7 Spec Line #28498wordingwordingEP Caterham 7 Spec Line removes redundant suspension note, clarifies engine prep limits and comp ratio to 10.0:1.
FP Request to classify SOHC 1989-90 240SX in F prod L2 #28553cars addedcars added1989-90 Nissan 240-SX SOHC added to FP Level 2 with 2400-2520 lbs weight range.
FA FA weight correction/clarification #28430wordingwordingFA engine note clarification removes Table E reference, Pro Formula Mazda directed to Table 1.
FP Request to allow 40 DCOE carb for the Datsun 510 #28195inductionfasterHP Datsun 510 gains 40 DCOE carburetor option alongside existing 40 DCN and 36mm DCNVH choices.
FP Request to classify Porsche 914 2L in LPrep FProd #28231cars addedcars addedPorsche 914-4 2.0L classified in FP Prep 2 at 2030-2132 lbs with 1968cc OHV engine, 11.0:1 compression limit, .450" valve lift limit.
FP Request Ford Fiesta Weight Adjustment #28336weightfasterFP Ford Fiesta 78-80 weight reduced 130 lbs to 1660.
FP Request for Help for Datsun 1200 #27934inductionfasterHP Datsun 1200 carburetor choke size increases from 26mm to 30mm.
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.
FP Request to List Mazda Miata Throttle Body Size #27907wordingwordingFP and EP Mazda Miata models standardized to 55mm throttle body diameter; brake spec clarified.
FP Request to Classify 2001-2003 Mazda Protege ES in FP #27922cars addedcars addedFP Mazda Protégé ES 01-03 newly classified at 2350–2468 lbs with 1991cc 4-cyl DOHC, fuel injection, 11.0:1 compression, .450 in. valve lift limit.
SRF3 SRF Rain / Brake Rule - BoD approved as follows #34958wordingwordingSRF rain and brake rule wording updated; supersedes GCR 9.3.32.B.2 effective 1/1/202 through 12/31/2024.
FA Move wheel dimensions from Bodywork subsection to #27493wordingwordingFA wheel dimension rules moved from Bodywork subsection to General section; no specification changes.
FA Table 2 Mazda MZR 2.0 E&O #27640wordingwordingFA Mazda MZR 2.0 now limited to Ralt RT40, Ralt RT41, and Swift 014 chassis only.
FP Request to Correct Track of 1988-91 Honda Civic #27487wordingwordingFP and HP Honda Civic and CRX 1988–91 track specifications corrected to 61.3/61.7 inches.
FP Re-organize Prep2 Cylinder Head Rules for Clarity & Consistency #27661wordingwordingEP, FP, HP cylinder head rules reorganized for clarity; no performance change.
SRF3 SRF Tire Warmer Rule #27622tyres & wheelsslowerSRF bans tire warmers and cooling methods other than natural air convection or conduction.
SRF3 SRF / SRF3 Nose Weight Reduction #27706weightfasterSRF front nose weight minimum reduced from 35 to 32 lbs.
SRF3 SRF / SRF3 Majors & Regional Class Updates #27723wordingwordingSRF3 reclassified as Spec Racer Ford 3 with 1.6L conversion; SRF2 becomes Regional Only Class.
FA Follow up to Letter #27344 on Honda Powered FA Rules #27363wordingwordingFA Honda Civic K20Z3 engines consolidated: three separate base/uprated specs removed, replaced with single unified 1350 lb minimum weight spec for Swift 014/016.
FA Swift 014 Mazda MZR 2.0 E&O #27305enginefasterFA Swift 014 Mazda MZR 2.0 piston minimum weight reduced from 320g to 280g.
FP Request bodywork for Austin Healey Bugeye Sprite MK1 #27106wordingwordingFP and HP Austin-Healey Sprite Mk I and MG Midget variants may replace rear bodywork aft of cockpit with stock-appearing alternate material components.
FP Request to classify the GMX5 2019 #27263wordingwordingEP Mazda MX-5 Global Cup classification year changes from 16-18 to 16-19.
FP Clarification of Carb Rules - Prep 1 #27300wordingwordingProduction carb rules clarified: carburetor options, fuel injection throttle body dimensions, and intake manifold restrictions reorganised and refined.
FP Clarification of Carb Rules - Prep 2 #27301wordingwordingEP, FP, HP carburetors clarified: jets, needles, metering rods, needle valves unrestricted; choke parts removable; permitted optional carburetors listed.
FP Request Miata Eligibility - 2003 #27121cars addedcars addedEP Mazda MX-5/Miata eligibility years expanded from 1999-2002 to 1999-2005.
SRF3 SRF Dash Windscreen Kit #27028wordingwordingSRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102.
FA Adjust Line N restrictor size and minimum weight #26691weight +30 lbsslowerFA Line N minimum weight increases to 1375 lbs.
SRF3 New SRF Sectional Nose Rule Addition #26914wordingwordingSRF3 nose assembly must use approved multi-piece design; no modifications allowed except as specified.
FA Add data plate requirement #26707wordingwordingFA cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs.
SRF3 SRF Brakes and Shock Rule Changes #26629wordingwordingSRF3 brakes now allow Hawk Blue 9012 pads P/N 801993 only; shocks simplified to Penske P/N 280396 sealed assembly only, with optional SCCA Enterprises bump rubber P/N 280407 from 05/01/2020.
FP Rollcenter Correction Clarification #25873suspension & brakesfasterEP, FP, HP clarified: tapered holes in ball joints now allowed for bolt conversion; wheel bearings and hubs unrestricted at any wheel.
FP Hardtops #26476wordingwordingEP open cars may now use aftermarket hardtops if they retain OEM appearance; specific model hardtop allowances removed.
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.
FP Request Classification of Dodge Daytona in F Production #26259cars added -150 lbsfasterFP Dodge Daytona/Chrysler Laser added at 2100/2153/2205 lbs; Shelby Charger/Omni 024 weight reduced to 2100/2153/2205 lbs.
FA FA MZR 2.0 Engine Specification #25814wordingwordingFA 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.
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 FA" is the class's best as a share of FA'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 FA'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.