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BoP Lab / Buttonwillow Raceway Park

F5 vs SRF vs F6 vs B-Spec pace at Buttonwillow Raceway Park

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

Quickest here: B-Spec 2:09.353 Trenton Kramer, Cal Club 2026 qualifying

2:092:102:1127 rule changes between Cal Club 2025 and Cal Club 202627 ▾B-Spec race best at Cal Club 2025: 2:10.054 (Thomas Lepper)B-Spec race best at Cal Club 2026: 2:09.916 (Trenton Kramer)B-Spec qualifying best at Cal Club 2025: 2:10.513 (Joseph Gersch)B-Spec qualifying best at Cal Club 2026: 2:09.353 (Trenton Kramer)Cal Club 20252025Cal Club 20262026
F5SRFF6B-Specsolid race · dashed qualifying · slower is lower
EventF5SRFF6B-Spec
Qual bestRace bestTrapQual bestRace bestTrapvs F5Qual bestRace bestTrapvs F5Qual bestRace bestTrapvs F5
Cal Club 2026 CALCL262026-02-212:09.353Trenton Kramer · fastest of 5 · top 5 within 6.1s-1.160s (-0.89%)2:09.916Trenton Kramer · fastest of 5 · top 5 within 2.7s-0.138s (-0.11%)121.5Trenton Kramer+23.3 mph (+23.8%)
27 rule changes (SRF: 3, B-Spec: 24)5 suspension & brakes · 3 cars added · 2 induction · 2 weight · 1 aero · 5 wording · 9 other · C-Spec adds approved rear sway bars for Chevrolet Cruze, Dodge Dart, Ford Focus, Honda Civic, Mazda3i, Mazda 3i, Toyota Corolla models. · B-Spec Chevrolet Sonic and Ford Fiesta and Honda Fit Notes sections reorganised for clarity; approved parts listed; no performance changes. · B-Spec: Sonic restrictors removed, Fit MT up 25 lbs to 2550, Fit CVT restrictor removed, Mini Coopers up 2 mm restrictor, Versa sedans down 25 lbs to 2425, Versa 2020+ and IA restrictors removed. · B-Spec Mazda2 10-14 exhaust header cat delete: only Mazda Motorsports PN 0000-06-2410 allowed, no weight adder. · B-Spec Honda Fit MT 07-08 now permits Torque Solution Shifter Cable Bushing kit TS-SCB-506. · B-Spec Ford Fiesta Hatchback gains 55 lbs to 2525, restrictor opens 39 to 40 mm FPR; Sedan gains 55 lbs to 2525, restrictor opens 38 to 39 mm FPR. · B-Spec Hyundai Accent Sedan and Kia Rio Sedan remove approved Bilstein B8 shock 33-187112 from rear suspension. · B-Spec Honda Fit MT 07-08 gains Bilstein B14 kit 47172401, Progress rear sway bar #62.1060, Injen intake SP1511, Torque Solution shifter cable bushing TS-SCB-506; Runoffs eligibility restriction removed. · B-Spec and C-Spec remove asterisk from Rule 9.1.10.D.9 public road use note. · B-Spec Honda Fit MT 09-14 may disable two pedal shutdown by cutting or de-pinning pin 42 BKSW at main ECU connector. · B-Spec Honda Fit MT 07-08 restricted to Injen Intake SP1511, cold air intakes no longer allowed; requires three Super Tour weekends and OBDII data collection. · B-Spec adds Hyundai Accent Sedan (12-17) and Kia Rio Sedan (12-17), both 1591cc, 2525 lbs, 40mm FPR restrictor. · B-Spec Honda Fit MT 09-14 adds allowed Acuity Shifter Base Bushing Kit 1954. · B-Spec Honda Fit AT 09-14 adds Weapon R Intake 301-166-301 as permitted option. · B-Spec and C-Spec shift linkages may now use approved aftermarket bushings; cables and linkage remain stock otherwise. · B-Spec Hyundai Accent Hatchback corrected to 12-17, Kia Rio Hatchback to 12-15. · B-Spec 07-08 Honda Fit MT minimum weight increases 50 lbs to 2450. · B-Spec Honda Fit 07-08 MT and AT now allow Bilstein B14 kit 47172401. · B-Spec: Honda Fit cold air intake restricted to three named parts with 25lb adder; Mazda2 exhaust headers allowed with weight adders; Mini Cooper FPR adjusted across six variants; Nissan Versa minimum weight cut 40lb with Injen intake allo… · B-Spec Accent and Yaris get brake-type weight adjustments: drum subtract 25 lb, disc add 25 lb. · B-Spec Hyundai Accent and Kia Rio (12-19) now allow Bilstein B14 kit #47167490 front shocks and BabyFace Fabrication sump extension #BF-HYU-PAN. · B-Spec Toyota Yaris Hatchback 12-18 rear brakes now allow 10.2 inch disc option alongside 7.9 drum. · B-Spec Toyota Yaris Hatchback and Sedan may now disconnect speed sensor. · B-Spec Fiat 500 (12-17) spec line expires 1/1/26 unless appeal filed.showhide
  • B-Spec C-Spec Rear Sway Bars #39652suspension & brakesadded · suspension & brakesC-Spec adds approved rear sway bars for Chevrolet Cruze, Dodge Dart, Ford Focus, Honda Civic, Mazda3i, Mazda 3i, Toyota Corolla models.
  • B-Spec Notes section cleanup #39062wordingwordingB-Spec Chevrolet Sonic and Ford Fiesta and Honda Fit Notes sections reorganised for clarity; approved parts listed; no performance changes.
  • B-Spec 2026 BOP Recommendations #39475induction +25 lbsunclearB-Spec: Sonic restrictors removed, Fit MT up 25 lbs to 2550, Fit CVT restrictor removed, Mini Coopers up 2 mm restrictor, Versa sedans down 25 lbs to 2425, Versa 2020+ and IA restrictors removed.
  • B-Spec Expire NLA Mazda 2 Headers #39582aeroremoved · aeroB-Spec Mazda2 10-14 exhaust header cat delete: only Mazda Motorsports PN 0000-06-2410 allowed, no weight adder.
  • B-Spec Alternate Shift Cable Bushings and Rear Spring Seats #38472otheraddedB-Spec Honda Fit MT 07-08 now permits Torque Solution Shifter Cable Bushing kit TS-SCB-506.
  • B-Spec Fiesta BOP Adjustment #38847weight +55 lbsfaster · weightB-Spec Ford Fiesta Hatchback gains 55 lbs to 2525, restrictor opens 39 to 40 mm FPR; Sedan gains 55 lbs to 2525, restrictor opens 38 to 39 mm FPR.
  • B-Spec Request to Remove Rear Shock From Spec Line Hyundai Accents/Kia #39017suspension & brakesremoved · suspension & brakesB-Spec Hyundai Accent Sedan and Kia Rio Sedan remove approved Bilstein B8 shock 33-187112 from rear suspension.
  • B-Spec Update Honda Fit MT (07-08) Runoffs Eligibility #39060cars addedaddedB-Spec Honda Fit MT 07-08 gains Bilstein B14 kit 47172401, Progress rear sway bar #62.1060, Injen intake SP1511, Torque Solution shifter cable bushing TS-SCB-506; Runoffs eligibility restriction removed.
  • SRF Add HD Oil Cooler #38979other
  • B-Spec Remove Asterisk from Rule 9 #38768wordingwordingB-Spec and C-Spec remove asterisk from Rule 9.1.10.D.9 public road use note.
  • B-Spec Disabling 2 Pedal Shutdown #38354otheraddedB-Spec Honda Fit MT 09-14 may disable two pedal shutdown by cutting or de-pinning pin 42 BKSW at main ECU connector.
  • B-Spec Update Honda Fit MT (07-08) Intake Allowance #38530wordingwordingB-Spec Honda Fit MT 07-08 restricted to Injen Intake SP1511, cold air intakes no longer allowed; requires three Super Tour weekends and OBDII data collection.
  • B-Spec Add Sedan spec lines for Hyundai & Kia #37537cars addedaddedB-Spec adds Hyundai Accent Sedan (12-17) and Kia Rio Sedan (12-17), both 1591cc, 2525 lbs, 40mm FPR restrictor.
  • B-Spec Shifter Bushing Questions. #38048otheraddedB-Spec Honda Fit MT 09-14 adds allowed Acuity Shifter Base Bushing Kit 1954.
  • B-Spec Add Weapon R Intake to Honda Fit MT (09-14) Spec Line #38306inductionadded · inductionB-Spec Honda Fit AT 09-14 adds Weapon R Intake 301-166-301 as permitted option.
  • B-Spec Update Rule 46 #38307wordingwordingB-Spec and C-Spec shift linkages may now use approved aftermarket bushings; cables and linkage remain stock otherwise.
  • B-Spec Correct Hyundai/Kia Model Years #37943wordingwordingB-Spec Hyundai Accent Hatchback corrected to 12-17, Kia Rio Hatchback to 12-15.
  • B-Spec 07-08 Honda Fit MT Requests #37974weight +50 lbsslower · weightB-Spec 07-08 Honda Fit MT minimum weight increases 50 lbs to 2450.
  • B-Spec Add B14 Kit Part # to Honda Fit (07-08) Spec line #38010suspension & brakesadded · suspension & brakesB-Spec Honda Fit 07-08 MT and AT now allow Bilstein B14 kit 47172401.
  • B-Spec 2025 BOP Recommendations #37520otherotherB-Spec: Honda Fit cold air intake restricted to three named parts with 25lb adder; Mazda2 exhaust headers allowed with weight adders; Mini Cooper FPR adjusted across six variants; Nissan Versa minimum weight cut 40lb with Injen intake allo…
  • B-Spec Hyundai/Toyota Factory Rear Disc Models #37534suspension & brakessuspension & brakesB-Spec Accent and Yaris get brake-type weight adjustments: drum subtract 25 lb, disc add 25 lb.
  • B-Spec Request to Update the Spec line for Hyundai Accent and Kia Rio #37880otheraddedB-Spec Hyundai Accent and Kia Rio (12-19) now allow Bilstein B14 kit #47167490 front shocks and BabyFace Fabrication sump extension #BF-HYU-PAN.
  • SRF Driver Safety & Comfort #37966other
  • SRF Update SADEV transmission specs #37992other
  • B-Spec Toyota Yaris Hatchback (12-18) rear disc brakes #37530suspension & brakessuspension & brakesB-Spec Toyota Yaris Hatchback 12-18 rear brakes now allow 10.2 inch disc option alongside 7.9 drum.
  • B-Spec Yaris Speed Sensor #37536otheraddedB-Spec Toyota Yaris Hatchback and Sedan may now disconnect speed sensor.
  • B-Spec Set Expiration Date For Fiat 500 #37689cars addedremoved · cars addedB-Spec Fiat 500 (12-17) spec line expires 1/1/26 unless appeal filed.
Cal Club 2025 CALCL252025-02-222:10.513Joseph Gersch · fastest of 4 · top 4 within 6.8s2:10.054Thomas Lepper · fastest of 4 · top 4 within 7.4s98.1Ali Naimi
159 earlier rule changes on record, in force before Cal Club 2025 (from 2019)26 cars added · 26 suspension & brakes · 16 tyres & wheels · 14 weight · 10 engine · 6 induction · 2 aero · 2 removed · 37 wording · 20 other · B-Spec and C-Spec remove redundant notes language from Honda Fit AT, Honda Fit CVT, Mazda2, Mini Cooper Hatchback MT and CVT, and Toyota Yaris Hatchback. · B-Spec removes Mini Cooper Countryman R60, Cooper Paceman R61, and Nissan Versa 07-11 and 09-11 spec lines. · B-Spec Nissan Micra Cup Car spec line expires 7/1/25 unless appeal submitted by 6/30/25. · B-Spec and C-Spec replace wheelbase spec with restrictor (mm) effective 2025-01-01; Sonic 33–36, Fiesta 38–39, Fit 31–33, Accent/Rio 41, Mini Cooper 40–46, Nissan Versa 38, Toyota IA/Yaris 38–42. · B-Spec Hyundai Accent and Kia Rio approved for Bilstein B8 shock 33-187112 in rear suspension. · B-Spec Toyota Scion IA Sedan 16-20 allows ST Suspension Kit 13275022; requires three Super Tour weekends and OBDII data collection before Runoffs eligibility. · Honda Fit AT 07-08 B-Spec notes simplified: specific damper, spring, and helper spring part numbers removed; Progress rear sway bar 62.1060 and any cold air intake now allowed. · B-Spec restricted to Goodyear Eagle RS dry and RS-R wet P205/50R15 tires; C-Spec 225/45R17 tire mixing prohibition clarified. · B-Spec automatics: Sonic restrictors to 35/36mm, Fit weights to 2350/2500 lbs, Fit CVT restrictor to 313mm, Mini weights to 2500 lbs, Mini restrictors to 35-46mm. · B-Spec and C-Spec hood pins now recommended but not required; factory release cable may be removed if pins used. · B-Spec Chevrolet Sonic and C-Spec Cruze allowed Babyface Fabrication brake caliper pistons SNC-SS and CRZ-SS. · B-Spec Honda Fit MT & CVT (15-19) notes cleaned up: removed obsolete parts, added rear sway bar Progress 62.1063 and CVT transmission cooler Setrab 50-119-7612. · B-Spec Nissan Versa 09-11 spec line expires 1 January 2025 unless appeal filed by 1 December 2024. · B-Spec removes redundant Rule 25 from GCR Section 9.1.10.E, effective 2024-07-01. · B-Spec Hyundai Accent rear brakes change to 10.3 disc; Kia Rio rear brakes change to 10.3 disc. · Chevrolet Sonic Spec lines add Bilstein B14 kit #47-171725 as verified compatible suspension option. · B-Spec and C-Spec: redundant sway bar end link part numbers removed from Mazda2 and eleven Mini Cooper variants' notes. · B-Spec Fiat 500 spec line year range changed from 12-15 to 12-17. · B-Spec Honda Fit CVT 15-19 minimum weight increases to 2550 lbs, intake restrictor to 31 mm. · B-Spec model descriptions standardized: trim levels removed, body styles clarified with consistent wording across Sonic, Fiesta, Fit, Accent, Rio, Versa, and Yaris. · B-Spec and C-Spec wheel rules clarified: tyre tread may not protrude beyond fender opening; wheel spacers allowed equally on all four corners; total offset must match left to right per axle. · B-Spec Honda Fit MT 15-19 restrictor increases 30mm to 31mm, minimum weight rises 2525 to 2550 lbs. · B-Spec and C-Spec gain wheel offset freedom and spacer flexibility; C-Spec wheels now differ per axle, not all four corners. · B-Spec Mini Cooper Countryman R60, Paceman R61, and Nissan Versa 07-11 1797cc expire 1/1/2025 without appeal by 12/1/2024. · B-Spec 07-08 Honda Fit Automatic allows rear sway bar Progress #62.1060; manual adds same part. · B-Spec and C-Spec auxiliary transmission cooler approval rule deleted. · B-Spec Chevrolet Sonic 5dr Hatch MT 12-19 allows aluminum radiator #ZZP-ZZ013. · 09-14 Honda Fit MT and AT now have separate spec lines with distinct gear ratios and final drive. · B-Spec Mazda2 10-14 minimum weight increases 70 lbs to 2350, headers and parts equalized effective 3-1-2024. · B-Spec Nissan Versa and Versa Note 2013–2019 permitted Hardrace HR-Q0146 19mm rear sway bar. · B-Spec Hankook tires allowed at regionals only through June 30, 2024; Goodyear becomes sole legal tire July 1, 2024. · B-Spec Nissan Versa Note Hatchback minimum weight drops 60 lbs to 2490; sedan line expanded to 2012–2019; 2013+ model deleted. · B-Spec and C-Spec clarify ECU must be unaltered OE, no altering devices allowed in grid to post-impound, and data acquisition systems expanded with new sensor types permitted. · C-Spec Mazda 3i 2010-2013 5-speed manual third gear ratio changes from 3.84 to 1.84. · C-Spec Dodge Dart 14-16 displacement corrected to 1998 cc, bore and stroke to 88.0 x 82.0 mm. · B-Spec adds Goodyear Eagle RS dry and wet tires; Hankook restricted to regional events from 2024. · C-Spec adds Chevrolet Cruze, Ford Focus, Honda Civic, Mazda 3i, Toyota Corolla, VW Jetta; updates Dodge Dart displacement to 2360 cc, Mazda3s model year, Toyota Corolla specs. · B-Spec Hyundai Accent GS Hatchback restrictor plate increases from 39 mm to 41 mm. · B-Spec Hyundai Accent GS Hatchback model years changed from 13–19 to 12–19. · B-Spec adds Hankook 200/580R15 Z217 option alongside 205/50R15 C51; C-Spec specifies 225/45R17 DOT tires unmodified. · B-Spec and C-Spec Chevrolet Sonic 12-19 allowed ZZP Aluminum Radiator #ZZP-ZZ013; Hatch MT restrictor changed to 34mm. · B-Spec and C-Spec bumper caps may use machine screws and T-nuts or rivet-nuts; self-drilling, tapping, and sheet metal screws prohibited. · B-Spec and C-Spec allow CAN bus connections to data systems for reading only, removing prior OBD2 restriction. · B-Spec Ford Fiesta 5dr and 4dr lose 25 lbs minimum weight, to 2470. · B-Spec Ford Fiesta 5dr, Fiesta 4dr, Honda Fit, Mazda2 lose weight; Mini Cooper variants gain weight and larger restrictors. · C-Spec Mazda 3i Touring 2.0 Skyactive MT 12-13 added with 2000 cc, 2900 lbs, 155 hp, 4.105 final drive. · B-Spec minimum ride height set to 6 inches, C-Spec to 5½ inches. · B-Spec spring rate stays 500 lb front and rear; C-Spec rises to 600 lb front, 800 lb rear. Spring strapping allowed for rebound only. · B-Spec wheels gain 13 lb minimum weight; C-Spec wheels gain 17 lb minimum weight. · B-Spec and C-Spec allowed metal threaded inserts in plastic intake manifolds for throttle body fasteners. · B-Spec and C-Spec rules clarified: wording changes to category terminology, manual priority scope, and technical requirements; no performance specifications altered. · B-Spec Mini Cooper R56 MT/AT and Clubman R55 fuel pressure regulator increased from 401mm to 40mm FPR with OBX header allowed. · B-Spec allows helper springs up to 500 lbs rate; tender springs now prohibited. · B-Spec Honda Fit 09-14 Automatic now permits any aftermarket exhaust or header; Manual unchanged. · B-Spec Chevrolet Sonic, Honda Fit, and Mini Cooper split into separate manual and automatic spec lines with distinct gear ratios and final drive ratios. · B-Spec tire options changed to Hankook 205/50R15 C51 or 200/580R15 Z217; no mixing wet and dry tires. · B-Spec Honda Fit 15-19 minimum weight cut to 2575 lbs from 2800 lbs. · F500 Rotax 493 and 593 intake boots: removed Moto Tassinari V3124-873B-2 from 493/593 non-HO allowance, added Moto Tassinari V3120-794A-2 option for non-HO. · B-Spec Mazda2 10-14 gains approved rear sway bar options 0000-04-2203-RR or 0000-04-2312. · F500 Rotax engines now permit Ingi Tech Sparker ignition DCP-CDI-P2 as alternate ECU. · F500 clarifies stepped diameter exhaust headers prohibited except at cylinder head flange area. · F500 Rotax 593 intake boot options clarified; oil injection pump removal now permitted. · B-Spec Hyundai Accent GS and Kia Rio 5-door restrictor increased from 36mm to 39mm flat plate. · B-Spec allows spring straps or zip ties to body for rebound control; OEM or kit bump stop requirement removed. · B-Spec strut tower modifications permitted for camber adjustment only, inboard movement, with shims or eccentric bolts on other suspension. · B-Spec Mazda2 10-14 allowed undertray part numbers corrected to DO8C-56-110A, DO8C-56-311, DO7A-56-321. · F500 Majors and Runoffs cars must install AIM part #X47KPFSOLO2R0 data box mount for Solo or Solo 2. · B-Spec classifies Nissan Versa S 2020- at 1598cc, 2618mm wheelbase, 2700 lbs minimum weight. · B-Spec: Toyota/Scion IA Sedan 2016–2020 added at 1496cc, 2700 lbs, 38mm FPR. · B-Spec Mazda 2 (10-14) removes Bilstein B14 kit, adds Powerflex bushings, radiator, three cat-delete headers, and undertray. · Honda Fit 2007-2008 automatic added to B-Spec at 2525 lbs with 1499 cc engine. · F5 cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs. · B-Spec upper strut slotted plates no longer required to use manufacturer's original bolt holes. · B-Spec upper strut slotted plates must use existing chassis structure, no longer limited to manufacturer's original bolt holes. · F5 clarifies mechanical shifting only; throttle-cut and flat-shifter devices permitted if driver retains full control. · F5 single-seat open-wheel cars: rigid suspension becomes limited suspension in class definition. · B-Spec Mazda2 10–14 gains optional header PN 0000-06-2410 with 70 lb. weight penalty. · B-Spec Honda Fit (09-14, 15-19) and Mini Cooper (R50, R56, 2011-13) add automatic transmission ratio and final drive options permitting Setrab 50-119-7612 cooler. · B-Spec Honda Fit 2007-08 added with 1499 cc displacement, 2450 mm wheelbase, 2525 lbs minimum weight. · B-Spec Ford Fiesta rear sway bar: Eibach #35143.312 or #35143.320 now allowed. · B-Spec restrictor changes from 0.060" to 0.050"-0.079" range. · B-Spec: rear window wipers and wiper motor removal now allowed. · F500 Rotax 593 HO engine now permitted; 875 lbs minimum weight, MA0242SP1020A or MA0242SP1063A restrictor, specific intake boots and piston required. · B-Spec R60 and R61 MINI allow 4-lug hub conversion with specified front and rear bearings and brake rotors. · B-Spec Mazda2 10-14 minimum weight rises to 2380 lbs; new header PN 0000-06-2401 required after 1/1/2023. · B-Spec Honda Fit eligible years extended from 2009–2012 to 2009–2014. · B-Spec Hyundai Accent GS and Kia Rio 5-door restrictor reduced from 40mm to 36mm flat plate. · B-Spec must use Hankook P205/50ZR15 Z214 C51 or Z217 rain tyre for SCCA Majors, Super Tour and Runoffs. · B-Spec tire rules clarified: Hankook Z214 dry and Z217 rain required at Majors/Super Tour/Runoffs after 6-1-2021; regionals allow any DOT race tire through 2021; wet tire permits 0.2" lower ride height. · B-Spec restrictor thickness set to 0.060 inches plus or minus 0.005 inches. · B-Spec Hyundai Accent GS Hatchback 2013-2019 classified at 2525 lbs with 40mm flat plate restrictor and specific suspension and sump parts allowed. · B-Spec Mini Cooper Countryman R60 and Paceman R61 production years corrected from 2011–13 to 2011–16. · B-Spec Toyota Yaris Hatch model year corrected from 07-12 to 07-11, and 12-18 Yaris renamed to Yaris Hatch. · B-Spec Mini Cooper all models: ride height minimum 5 inches measured from metal under door rocker molding. · B-Spec brake dust shields may now be removed or modified by removing material. · B-Spec Mini Cooper Clubman R55 11-15 now allows OBX header 10-2101-2S with 40mm flat plate restrictor. · B-Spec clarifies B14 Bilstein shock approval process; removes specific B14 kit allowances from eight car spec lines, requiring CRB approval instead. · B-Spec removes Chevrolet Sonic (12-19); renames Toyota Yaris (07-12) to Hatch; limits Yaris Sedan to 07-12. · F500 Suzuki GSXR600 engine years extended from 2003-2013 to 2003-2019. · B-Spec Mini Cooper R56 40mm restrictor requirement removed; suspension parts and OBX header with restrictor now allowed. · F5 request to adjust external jetting device cockpit control denied; no rule change made. · F5 cockpit adjustment request response published in Fastrack letter 28359. · B-Spec wheelbase specifications converted from inches to millimetres for all cars across the class. · B-Spec Chevrolet Sonic adds 5dr Hatch with 34mm restrictor; both body styles allow Setrab FP119M221 transmission cooler for automatic cars. · B-Spec: multiple models allow specific suspension kits and damper assemblies, effective 2020-05-01. · B-Spec sunroof retention wording clarified; cars must retain sunroofs securely bolted unless rails adequately secure the panel. · B-Spec Ford Fiesta 5dr gets 36mm restrictor, 4dr gets 34mm; Honda Fit 09-12 loses 25 lbs to 2525; Fit 15-20 restrictor tightens to 30mm; Mini Cooper 07-10 gets 40mm restrictor. · B-Spec Chevrolet Sonic, Fiat 500, Ford Fiesta 5dr and 4dr, Honda Fit model years expanded to include 2019 or through 2019. · B-Spec adds six Mini Cooper models (02-06 R50, 07-10 R55, 12-15 R58, 11-15 R55, 11-13 R60, R61), weights 2545–2625 lbs, four with 40 mm restrictor. · B-Spec fog lamps may now be removed; holes must be completely covered. · B-Spec adds Chevrolet Sonic 4dr Sedan 12–19, 1796 cc, 2650 lbs, with 32mm restrictor. · B-Spec automatic and CVT transmissions now legal for all permitted cars meeting their spec line; OEM paddle shifters acceptable. · B-Spec automatic transmissions may use auxiliary coolers on case-by-case approval with submitted part numbers. · B-Spec adds Toyota Yaris Sedan 2007-, 1491 cc, 2400 lbs, with specified Bilstein, swaybar, and K&N intake. · B-Spec adds 2011-2016 Ford Fiesta 4dr Sedan, 1596 cc, 2495 lbs minimum weight. · B-Spec Kia Rio 5-door LX model years extended to 2012–2019. · B-Spec Mazda2 10-14: suspension parts, intake, exhaust header, and bushings added to allowed list. · F500 Honda CBR600RR, Suzuki GSXR600, Yamaha R6 restrictor reduced to 28mm from 29mm. · B-Spec Mini Cooper production years clarified to 2011-13. · B-Spec Mazda 2, Fiat 500, 2007–10 Mini Cooper permitted to replace primary cat/exhaust manifold with approved header, retaining oxygen sensors. · B-Spec removes time limit on car eligibility; cars now compete indefinitely once classified. · B-Spec Honda Fit model year range extended to include 2013. · F500 Honda CBR600RR, Suzuki GSXR600, and Yamaha R6 minimum weights increase to 900 lbs. · B-Spec 2007-10 Mini Cooper adds OBX header part #10-2101-2S as E&O allowance. · B-Spec added to GCR 9.3.26 fuel cell exception list; stock fuel tank permitted. · B-Spec adds Canadian Nissan Micra Cup Car, 1598 cc, 2450 lbs minimum, with Micra Cup suspension kit allowed. · B-Spec Toyota Yaris 12-18 added with 1491cc engine, 3.55 first gear, Bilstein B14 suspension, K&N intake allowed. · B-Spec exhaust wording clarified: oxygen sensors must stay stock location, primary catalyst unmodifiable.showhide
  • B-Spec Remove Redundant Language from Notes Sections #37337wordingwordingB-Spec and C-Spec remove redundant notes language from Honda Fit AT, Honda Fit CVT, Mazda2, Mini Cooper Hatchback MT and CVT, and Toyota Yaris Hatchback.
  • B-Spec Expire designated spec lines #37517removedremovedB-Spec removes Mini Cooper Countryman R60, Cooper Paceman R61, and Nissan Versa 07-11 and 09-11 spec lines.
  • B-Spec Set expiration date for Nissan Micra Cup Cars (Canadian) #37519wordingremovedB-Spec Nissan Micra Cup Car spec line expires 7/1/25 unless appeal submitted by 6/30/25.
  • B-Spec Remove wheelbase from spec lines and replace with Restrictor #36074enginefaster · engineB-Spec and C-Spec replace wheelbase spec with restrictor (mm) effective 2025-01-01; Sonic 33–36, Fiesta 38–39, Fit 31–33, Accent/Rio 41, Mini Cooper 40–46, Nissan Versa 38, Toyota IA/Yaris 38–42.
  • B-Spec Bilstein Rear Shock Request for Hyundai Accent/Kia Rio #36965suspension & brakesadded · suspension & brakesB-Spec Hyundai Accent and Kia Rio approved for Bilstein B8 shock 33-187112 in rear suspension.
  • B-Spec Scion IA/Toyota Yaris/Mazda 2 DY chassis suspension #35780suspension & brakesadded · suspension & brakesB-Spec Toyota Scion IA Sedan 16-20 allows ST Suspension Kit 13275022; requires three Super Tour weekends and OBDII data collection before Runoffs eligibility.
  • B-Spec Clean up 07-08 Honda Fit AT Notes Section #36542wordingwordingHonda Fit AT 07-08 B-Spec notes simplified: specific damper, spring, and helper spring part numbers removed; Progress rear sway bar 62.1060 and any cold air intake now allowed.
  • SRF Update SRF3 Air Filter Rule #36681other
  • SRF Update SRF Brake Rotor Thickness #36687suspension & brakes
  • SRF Hoosier Tire Decal Placement #36739tyres & wheels
  • SRF Protest Fee Clarification #36540wording
  • SRF Update to Letter 36619 with new Hoosier Contingency Decal Info #36624tyres & wheels
  • B-Spec Update Tire Rules #35984tyres & wheelstyres & wheelsB-Spec restricted to Goodyear Eagle RS dry and RS-R wet P205/50R15 tires; C-Spec 225/45R17 tire mixing prohibition clarified.
  • B-Spec BOP help for the automatic B-Specs #36161induction -50 lbsfaster · inductionB-Spec automatics: Sonic restrictors to 35/36mm, Fit weights to 2350/2500 lbs, Fit CVT restrictor to 313mm, Mini weights to 2500 lbs, Mini restrictors to 35-46mm.
  • B-Spec Require hood pins #36233wordingwordingB-Spec and C-Spec hood pins now recommended but not required; factory release cable may be removed if pins used.
  • B-Spec Sonic Caliper Pistons #36238tyres & wheelsadded · tyres & wheelsB-Spec Chevrolet Sonic and C-Spec Cruze allowed Babyface Fabrication brake caliper pistons SNC-SS and CRZ-SS.
  • SRF Update Rain Tire Rule and Hoosier Decal Placement #36436tyres & wheels
  • B-Spec Clean up (15-19) Honda Fit MT & CVT Notes Sections #36068wordingwordingB-Spec Honda Fit MT & CVT (15-19) notes cleaned up: removed obsolete parts, added rear sway bar Progress 62.1063 and CVT transmission cooler Setrab 50-119-7612.
  • B-Spec Set expiration date for Nissan Versa (09-11) #36069cars addedremoved · cars addedB-Spec Nissan Versa 09-11 spec line expires 1 January 2025 unless appeal filed by 1 December 2024.
  • B-Spec Delete Redundant Rule 25 #36075wordingwordingB-Spec removes redundant Rule 25 from GCR Section 9.1.10.E, effective 2024-07-01.
  • B-Spec Correct error for rear brakes of Hyundai/Kia #36174suspension & brakessuspension & brakesB-Spec Hyundai Accent rear brakes change to 10.3 disc; Kia Rio rear brakes change to 10.3 disc.
  • B-Spec Add B14 Kit Part # to Sonic Spec line In #35969suspension & brakesadded · suspension & brakesChevrolet Sonic Spec lines add Bilstein B14 kit #47-171725 as verified compatible suspension option.
  • B-Spec Eliminate redundant sway bar end link part #s from notes In #35970wordingwordingB-Spec and C-Spec: redundant sway bar end link part numbers removed from Mazda2 and eleven Mini Cooper variants' notes.
  • B-Spec Update Fiat 500 Spec line In #35990cars addedaddedB-Spec Fiat 500 spec line year range changed from 12-15 to 12-17.
  • B-Spec Update (15-19) Honda Fit #36067weight +25 lbsslower · weightB-Spec Honda Fit CVT 15-19 minimum weight increases to 2550 lbs, intake restrictor to 31 mm.
  • B-Spec Delete trim levels/update language for spec lines #35746wordingwordingB-Spec model descriptions standardized: trim levels removed, body styles clarified with consistent wording across Sonic, Fiesta, Fit, Accent, Rio, Versa, and Yaris.
  • B-Spec Wheel Rules #36066wordingwordingB-Spec and C-Spec wheel rules clarified: tyre tread may not protrude beyond fender opening; wheel spacers allowed equally on all four corners; total offset must match left to right per axle.
  • B-Spec Change restrictor from 30mm to 31mm (2015+ Honda Fit) and add 50# #34857inductionfaster · inductionB-Spec Honda Fit MT 15-19 restrictor increases 30mm to 31mm, minimum weight rises 2525 to 2550 lbs.
  • B-Spec Wheel Offset and Spacer Revision #35466suspension & brakessuspension & brakesB-Spec and C-Spec gain wheel offset freedom and spacer flexibility; C-Spec wheels now differ per axle, not all four corners.
  • B-Spec Set Expiration Date for Unused Spec Lines #35742wordingwordingB-Spec Mini Cooper Countryman R60, Paceman R61, and Nissan Versa 07-11 1797cc expire 1/1/2025 without appeal by 12/1/2024.
  • B-Spec BOP Adjustment for Yaris iA, 2020+ Versa, and 07-08 Honda Fit #35382weight -125 lbs
  • B-Spec 07-08 Honda Fit Rear Sway Bar part # #35473otherotherB-Spec 07-08 Honda Fit Automatic allows rear sway bar Progress #62.1060; manual adds same part.
  • B-Spec Eliminate Redundant Trans Cooler Rule #35353removedremovedB-Spec and C-Spec auxiliary transmission cooler approval rule deleted.
  • B-Spec Fix Sonic Hatchback MT Spec Line #35371otheraddedB-Spec Chevrolet Sonic 5dr Hatch MT 12-19 allows aluminum radiator #ZZP-ZZ013.
  • B-Spec Split Spec Line of Automatic and Manual 2nd Gen (09-14) Fit #35251cars addedadded09-14 Honda Fit MT and AT now have separate spec lines with distinct gear ratios and final drive.
  • B-Spec Equalize Mazda 2 Headers and clean up spec line #35259weightslower · weightB-Spec Mazda2 10-14 minimum weight increases 70 lbs to 2350, headers and parts equalized effective 3-1-2024.
  • B-Spec Rear Sway Bar Request for Nissan Versa and Versa Note 2013- #35323suspension & brakesadded · suspension & brakesB-Spec Nissan Versa and Versa Note 2013–2019 permitted Hardrace HR-Q0146 19mm rear sway bar.
  • B-Spec B-Spec Hankook Tire for Regionals #35055tyres & wheelstyres & wheelsB-Spec Hankook tires allowed at regionals only through June 30, 2024; Goodyear becomes sole legal tire July 1, 2024.
  • B-Spec Update 12-19 Nissan Versa Spec Line & Adjust BOP #35074weight -60 lbsfaster · weightB-Spec Nissan Versa Note Hatchback minimum weight drops 60 lbs to 2490; sedan line expanded to 2012–2019; 2013+ model deleted.
  • B-Spec Clarifying the ECU and Data Acquisition language #35236wordingwordingB-Spec and C-Spec clarify ECU must be unaltered OE, no altering devices allowed in grid to post-impound, and data acquisition systems expanded with new sensor types permitted.
  • SRF Update SRF Rain / Brake Rule #34706suspension & brakes
  • SRF Update SRF Brake Light Rule v1 #34853suspension & brakes
  • SRF SRF / SRF3 Rule Updates #35268weight
  • B-Spec Mazda 3i 2010-2013 5-Speed Manual Gear Ratios #34820wordingwordingC-Spec Mazda 3i 2010-2013 5-speed manual third gear ratio changes from 3.84 to 1.84.
  • B-Spec Error Correction #34955wordingwordingC-Spec Dodge Dart 14-16 displacement corrected to 1998 cc, bore and stroke to 88.0 x 82.0 mm.
  • B-Spec B-Spec Tire #35034tyres & wheelsadded · tyres & wheelsB-Spec adds Goodyear Eagle RS dry and wet tires; Hankook restricted to regional events from 2024.
  • SRF SRF Radiator Rule Update #34805other
  • B-Spec Initial car classifications and spec lines #34461cars addedaddedC-Spec adds Chevrolet Cruze, Ford Focus, Honda Civic, Mazda 3i, Toyota Corolla, VW Jetta; updates Dodge Dart displacement to 2360 cc, Mazda3s model year, Toyota Corolla specs.
  • B-Spec Hyundai Accent Restrictor Plate #34331inductionfaster · inductionB-Spec Hyundai Accent GS Hatchback restrictor plate increases from 39 mm to 41 mm.
  • B-Spec Hyundai Accent 2012 Model #34332cars addedaddedB-Spec Hyundai Accent GS Hatchback model years changed from 13–19 to 12–19.
  • B-Spec T5 Tire Options #33641tyres & wheelsadded · tyres & wheelsB-Spec adds Hankook 200/580R15 Z217 option alongside 205/50R15 C51; C-Spec specifies 225/45R17 DOT tires unmodified.
  • B-Spec Allow ZZP Sonic Aluminum Radiator 1.68 #33660wordingwordingB-Spec and C-Spec Chevrolet Sonic 12-19 allowed ZZP Aluminum Radiator #ZZP-ZZ013; Hatch MT restrictor changed to 34mm.
  • B-Spec Fasteners for Bumper Caps #33797otheraddedB-Spec and C-Spec bumper caps may use machine screws and T-nuts or rivet-nuts; self-drilling, tapping, and sheet metal screws prohibited.
  • B-Spec Allow CAN Bus Connection to Data Systems #33806otheraddedB-Spec and C-Spec allow CAN bus connections to data systems for reading only, removing prior OBD2 restriction.
  • B-Spec Request Ford Fiesta weight reduction 25lbs #33890weight -25 lbsfaster · weightB-Spec Ford Fiesta 5dr and 4dr lose 25 lbs minimum weight, to 2470.
  • B-Spec BoB Adjustments #34208weight -25 lbsunclearB-Spec Ford Fiesta 5dr, Fiesta 4dr, Honda Fit, Mazda2 lose weight; Mini Cooper variants gain weight and larger restrictors.
  • B-Spec T5 Mazda 3 Spec Line Addition #33536cars addedaddedC-Spec Mazda 3i Touring 2.0 Skyactive MT 12-13 added with 2000 cc, 2900 lbs, 155 hp, 4.105 final drive.
  • B-Spec T5 Ride Height Rules. #33552suspension & brakesadded · suspension & brakesB-Spec minimum ride height set to 6 inches, C-Spec to 5½ inches.
  • B-Spec T5 Spring Allowance #33557suspension & brakesfaster · suspension & brakesB-Spec spring rate stays 500 lb front and rear; C-Spec rises to 600 lb front, 800 lb rear. Spring strapping allowed for rebound only.
  • B-Spec T5 Wheel Minimum Weight #33558weightslower · weightB-Spec wheels gain 13 lb minimum weight; C-Spec wheels gain 17 lb minimum weight.
  • B-Spec Threaded Metal Inserts for Plastic Intake Manifolds #34164otheraddedB-Spec and C-Spec allowed metal threaded inserts in plastic intake manifolds for throttle body fasteners.
  • SRF Hoosier SRF Wet Front Tire Rule Update #34189tyres & wheels
  • B-Spec T5 Rules Feedback #33595wordingwordingB-Spec and C-Spec rules clarified: wording changes to category terminology, manual priority scope, and technical requirements; no performance specifications altered.
  • SRF Update SRF Front W2 Rain Tire Part Number #34118tyres & wheels
  • B-Spec Early Model Mini #33363wordingunclearB-Spec Mini Cooper R56 MT/AT and Clubman R55 fuel pressure regulator increased from 401mm to 40mm FPR with OBX header allowed.
  • B-Spec Helper Versus Tender springs. #33866suspension & brakessuspension & brakesB-Spec allows helper springs up to 500 lbs rate; tender springs now prohibited.
  • SRF Update SRF Brake Rule #33469suspension & brakes
  • B-Spec Split up Spec lines for Automatic/Manual 2nd Gen Fit #33292otheraddedB-Spec Honda Fit 09-14 Automatic now permits any aftermarket exhaust or header; Manual unchanged.
  • B-Spec Request to Split Spec Lines for Automatic Models #33270wordingwordingB-Spec Chevrolet Sonic, Honda Fit, and Mini Cooper split into separate manual and automatic spec lines with distinct gear ratios and final drive ratios.
  • B-Spec Tire Rule Request #33350tyres & wheelstyres & wheelsB-Spec tire options changed to Hankook 205/50R15 C51 or 200/580R15 Z217; no mixing wet and dry tires.
  • B-Spec Utilize the Data - Make BoP Changes #32179weight -225 lbsfaster · weightB-Spec Honda Fit 15-19 minimum weight cut to 2575 lbs from 2800 lbs.
  • F5 Intake Boots Correction #33028wordingwordingF500 Rotax 493 and 593 intake boots: removed Moto Tassinari V3124-873B-2 from 493/593 non-HO allowance, added Moto Tassinari V3120-794A-2 option for non-HO.
  • B-Spec Request new Mazda Rear Swaybar #32769suspension & brakesadded · suspension & brakesB-Spec Mazda2 10-14 gains approved rear sway bar options 0000-04-2203-RR or 0000-04-2312.
  • F5 Ensure availability of ECU for Rotax engines #32695engineadded · engineF500 Rotax engines now permit Ingi Tech Sparker ignition DCP-CDI-P2 as alternate ECU.
  • F5 Clarify stepped exhaust header references #32743wordingwordingF500 clarifies stepped diameter exhaust headers prohibited except at cylinder head flange area.
  • F5 593 carb boot availability and oil pump clarification #32527wordingwordingF500 Rotax 593 intake boot options clarified; oil injection pump removal now permitted.
  • SRF SRF Tire Rule Update #32614tyres & wheels
  • SRF Brake, seal, and air filter clarifications #32670suspension & brakes
  • B-Spec Request to Remove Part Numbers from Kia/Hyundai Spec Lines #32378inductionfaster · inductionB-Spec Hyundai Accent GS and Kia Rio 5-door restrictor increased from 36mm to 39mm flat plate.
  • B-Spec Request spring attachment #31351suspension & brakessuspension & brakesB-Spec allows spring straps or zip ties to body for rebound control; OEM or kit bump stop requirement removed.
  • B-Spec Limit Rear Camber to 1.75 Degrees Section 9.1.10.E.35 #31393suspension & brakessuspension & brakesB-Spec strut tower modifications permitted for camber adjustment only, inboard movement, with shims or eccentric bolts on other suspension.
  • B-Spec Letter 31442 Part# Correction #32060wordingwordingB-Spec Mazda2 10-14 allowed undertray part numbers corrected to DO8C-56-110A, DO8C-56-311, DO7A-56-321.
  • F5 E&O class name #32194otheraddedF500 Majors and Runoffs cars must install AIM part #X47KPFSOLO2R0 data box mount for Solo or Solo 2.
  • B-Spec Request to Classify 2020-21 Versa S #30759cars addedaddedB-Spec classifies Nissan Versa S 2020- at 1598cc, 2618mm wheelbase, 2700 lbs minimum weight.
  • B-Spec Request to Classify the Toyota IA sedan & Scion IA Sedan for 2022 #31045cars addedaddedB-Spec: Toyota/Scion IA Sedan 2016–2020 added at 1496cc, 2700 lbs, 38mm FPR.
  • B-Spec Mazda 2 Undertray #31442otherotherB-Spec Mazda 2 (10-14) removes Bilstein B14 kit, adds Powerflex bushings, radiator, three cat-delete headers, and undertray.
  • B-Spec Request to add 2007-2008 Honda Fit #30853cars addedaddedHonda Fit 2007-2008 automatic added to B-Spec at 2525 lbs with 1499 cc engine.
  • F5 Data Box Mounting Plate #31638otheraddedF5 cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs.
  • SRF Three Updates to SRF Rules #31523weight
  • B-Spec Rules Clarification of Body and Camber Plates #30814suspension & brakessuspension & brakesB-Spec upper strut slotted plates no longer required to use manufacturer's original bolt holes.
  • B-Spec Rules Clarification of Body and Camber Plates #30814suspension & brakesadded · suspension & brakesB-Spec upper strut slotted plates must use existing chassis structure, no longer limited to manufacturer's original bolt holes.
  • F5 Clarify allowable assisted shifting systems #30871wordingwordingF5 clarifies mechanical shifting only; throttle-cut and flat-shifter devices permitted if driver retains full control.
  • F5 Request to correct terminology #30976wordingwordingF5 single-seat open-wheel cars: rigid suspension becomes limited suspension in class definition.
  • SRF SRF Wet Tires #30849tyres & wheels
  • SRF SADEV-SRF3 Transmission #30926other
  • SRF SRF Update Maintenance, Repairs and Seals #30961engine
  • B-Spec B-Spec Mazda2 Header Update #30884otheraddedB-Spec Mazda2 10–14 gains optional header PN 0000-06-2410 with 70 lb. weight penalty.
  • B-Spec Transmission Cooler Requests #30079otheraddedB-Spec Honda Fit (09-14, 15-19) and Mini Cooper (R50, R56, 2011-13) add automatic transmission ratio and final drive options permitting Setrab 50-119-7612 cooler.
  • B-Spec Request to classify the 07 Honda Fit #30083cars addedaddedB-Spec Honda Fit 2007-08 added with 1499 cc displacement, 2450 mm wheelbase, 2525 lbs minimum weight.
  • B-Spec Request Ford Fiesta Eibach Rear Sway Bar Part Number 35143.320 #30340suspension & brakesadded · suspension & brakesB-Spec Ford Fiesta rear sway bar: Eibach #35143.312 or #35143.320 now allowed.
  • B-Spec Restrictor rule #30474enginefaster · engineB-Spec restrictor changes from 0.060" to 0.050"-0.079" range.
  • B-Spec Rear wipers on all cars #30585aerofaster · aeroB-Spec: rear window wipers and wiper motor removal now allowed.
  • F5 Request to Allow Rotax 593 HO Engine #30712cars addedaddedF500 Rotax 593 HO engine now permitted; 875 lbs minimum weight, MA0242SP1020A or MA0242SP1063A restrictor, specific intake boots and piston required.
  • SRF SRF3 Alternator Pulley #30684weight
  • B-Spec Allow 4 lug hub conversion to R60 and R61 MINI #29863otheraddedB-Spec R60 and R61 MINI allow 4-lug hub conversion with specified front and rear bearings and brake rotors.
  • B-Spec Mazda2 header replacement #29944weight +50 lbsslower · weightB-Spec Mazda2 10-14 minimum weight rises to 2380 lbs; new header PN 0000-06-2401 required after 1/1/2023.
  • B-Spec Honda Fit Years on Spec Line #30078cars addedaddedB-Spec Honda Fit eligible years extended from 2009–2012 to 2009–2014.
  • B-Spec Hyundai/Kia restrictor size incorrect #30380engineslower · engineB-Spec Hyundai Accent GS and Kia Rio 5-door restrictor reduced from 40mm to 36mm flat plate.
  • B-Spec Clarify tire compound in rules #30387tyres & wheelstyres & wheelsB-Spec must use Hankook P205/50ZR15 Z214 C51 or Z217 rain tyre for SCCA Majors, Super Tour and Runoffs.
  • B-Spec Spec Tire Recommendation #29480tyres & wheelstyres & wheelsB-Spec tire rules clarified: Hankook Z214 dry and Z217 rain required at Majors/Super Tour/Runoffs after 6-1-2021; regionals allow any DOT race tire through 2021; wet tire permits 0.2" lower ride height.
  • B-Spec Make restrictor thickness unique for B Spec #30349wordingwordingB-Spec restrictor thickness set to 0.060 inches plus or minus 0.005 inches.
  • SRF Mandatory identification: #30223engine
  • B-Spec Request to Classify Hyundai Accent (RB) 2012-2019 #29484cars addedaddedB-Spec Hyundai Accent GS Hatchback 2013-2019 classified at 2525 lbs with 40mm flat plate restrictor and specific suspension and sump parts allowed.
  • B-Spec Countryman production years incorrect #29864wordingwordingB-Spec Mini Cooper Countryman R60 and Paceman R61 production years corrected from 2011–13 to 2011–16.
  • B-Spec Toyota Yaris Model Year Corrections #29896wordingwordingB-Spec Toyota Yaris Hatch model year corrected from 07-12 to 07-11, and 12-18 Yaris renamed to Yaris Hatch.
  • B-Spec Correction spec lines for ride height Mini Cooper all models #29952wordingwordingB-Spec Mini Cooper all models: ride height minimum 5 inches measured from metal under door rocker molding.
  • B-Spec Request to Allow Removal of Stock Brake Dust Shields #29981suspension & brakessuspension & brakesB-Spec brake dust shields may now be removed or modified by removing material.
  • B-Spec Request to allow OBX header and restrictor to R55 Clubman 08-10 #30024otheraddedB-Spec Mini Cooper Clubman R55 11-15 now allows OBX header 10-2101-2S with 40mm flat plate restrictor.
  • B-Spec Request clarification of B14 shock package for any and all cars #29483wordingwordingB-Spec clarifies B14 Bilstein shock approval process; removes specific B14 kit allowances from eight car spec lines, requiring CRB approval instead.
  • B-Spec Cleanup of spec lines #29495cars addedremoved · cars addedB-Spec removes Chevrolet Sonic (12-19); renames Toyota Yaris (07-12) to Hatch; limits Yaris Sedan to 07-12.
  • SRF SRF Shocks, Springs and Ride Height. #29688suspension & brakes
  • F5 Request to Update Suzuki Engine Years for F500 #29453engineadded · engineF500 Suzuki GSXR600 engine years extended from 2003-2013 to 2003-2019.
  • B-Spec Allowance Versus Requirement for R56 Mini Cooper #29127enginefaster · engineB-Spec Mini Cooper R56 40mm restrictor requirement removed; suspension parts and OBX header with restrictor now allowed.
  • F5 Request for Cockpit Adjustment of External Jetting Devices #28359wordingunclearF5 request to adjust external jetting device cockpit control denied; no rule change made.
  • F5 Two Stroke Motors (reply to #28359 WDYT) #28816engine
  • F5 Re letter requesting driver adjustable carb mixture #28840other
  • F5 #28359 WDYT Request for Cockpit Adjustment #28875wordingunclearF5 cockpit adjustment request response published in Fastrack letter 28359.
  • B-Spec Request to change units on wheelbase for consistency with wording #28786wordingwordingB-Spec wheelbase specifications converted from inches to millimetres for all cars across the class.
  • B-Spec Transmission cooler for automatic equipped cars #28171cars addedaddedB-Spec Chevrolet Sonic adds 5dr Hatch with 34mm restrictor; both body styles allow Setrab FP119M221 transmission cooler for automatic cars.
  • B-Spec Spring Update for all models #28384suspension & brakesadded · suspension & brakesB-Spec: multiple models allow specific suspension kits and damper assemblies, effective 2020-05-01.
  • B-Spec Request to Cleanup Sunroof Wording #28401wordingwordingB-Spec sunroof retention wording clarified; cars must retain sunroofs securely bolted unless rails adequately secure the panel.
  • B-Spec B-Spec Balance of Performance based on 2018 and 2019 seasons #28394induction -25 lbsslower · inductionB-Spec Ford Fiesta 5dr gets 36mm restrictor, 4dr gets 34mm; Honda Fit 09-12 loses 25 lbs to 2525; Fit 15-20 restrictor tightens to 30mm; Mini Cooper 07-10 gets 40mm restrictor.
  • SRF SRF Bump Stop Correction #27019suspension & brakes
  • B-Spec Request for Model Years Updating #27850cars addedaddedB-Spec Chevrolet Sonic, Fiat 500, Ford Fiesta 5dr and 4dr, Honda Fit model years expanded to include 2019 or through 2019.
  • B-Spec Request to classify Min Cooper models #27861cars addedaddedB-Spec adds six Mini Cooper models (02-06 R50, 07-10 R55, 12-15 R58, 11-15 R55, 11-13 R60, R61), weights 2545–2625 lbs, four with 40 mm restrictor.
  • B-Spec remove fog lights #27947wordingremovedB-Spec fog lamps may now be removed; holes must be completely covered.
  • B-Spec add sonic sedan #27948cars addedaddedB-Spec adds Chevrolet Sonic 4dr Sedan 12–19, 1796 cc, 2650 lbs, with 32mm restrictor.
  • B-Spec Request for Automatic Transmission Inclusion #27686cars addedaddedB-Spec automatic and CVT transmissions now legal for all permitted cars meeting their spec line; OEM paddle shifters acceptable.
  • B-Spec Request to Add Transmission Coolers to Automatics #27687otheraddedB-Spec automatic transmissions may use auxiliary coolers on case-by-case approval with submitted part numbers.
  • B-Spec Add Yaris Sedan #26797cars addedaddedB-Spec adds Toyota Yaris Sedan 2007-, 1491 cc, 2400 lbs, with specified Bilstein, swaybar, and K&N intake.
  • B-Spec Add 2011-2016 Fiesta Sedan #26798cars addedaddedB-Spec adds 2011-2016 Ford Fiesta 4dr Sedan, 1596 cc, 2495 lbs minimum weight.
  • B-Spec add 2015-2019 Kia Rio #26799cars addedaddedB-Spec Kia Rio 5-door LX model years extended to 2012–2019.
  • B-Spec Error and Omissions #27858suspension & brakesadded · suspension & brakesB-Spec Mazda2 10-14: suspension parts, intake, exhaust header, and bushings added to allowed list.
  • F5 Change 600cc restrictor size #27883inductionslower · inductionF500 Honda CBR600RR, Suzuki GSXR600, Yamaha R6 restrictor reduced to 28mm from 29mm.
  • SRF SRF Rain / Brake Rule - BoD approved as follows #34958suspension & brakes
  • B-Spec Request for Correction of Production Years for Mini Cooper #27226wordingwordingB-Spec Mini Cooper production years clarified to 2011-13.
  • SRF SRF Tire Warmer Rule #27622tyres & wheels
  • SRF SRF / SRF3 Nose Weight Reduction #27706weight
  • SRF SRF / SRF3 Majors & Regional Class Updates #27723other
  • B-Spec Request for Corrections to 9.1.10 E Item #27 D and E #27224aeroadded · aeroB-Spec Mazda 2, Fiat 500, 2007–10 Mini Cooper permitted to replace primary cat/exhaust manifold with approved header, retaining oxygen sensors.
  • B-Spec Remove wording in the B-spec rules #27388wordingaddedB-Spec removes time limit on car eligibility; cars now compete indefinitely once classified.
  • B-Spec Request to add 2013 Honda Fit model year #27491cars addedaddedB-Spec Honda Fit model year range extended to include 2013.
  • F5 Request for Weight Increase for Motorcycle Powered Cars #27214weight +25 lbsslower · weightF500 Honda CBR600RR, Suzuki GSXR600, and Yamaha R6 minimum weights increase to 900 lbs.
  • B-Spec Request to allow OBX Header for 2007-10 Mini Cooper #26977engineadded · engineB-Spec 2007-10 Mini Cooper adds OBX header part #10-2101-2S as E&O allowance.
  • SRF SRF Dash Windscreen Kit #27028other
  • B-Spec Request to add B-Spec to GCR 9.3.26 fuel cell #26132cars addedaddedB-Spec added to GCR 9.3.26 fuel cell exception list; stock fuel tank permitted.
  • B-Spec Request to classify Canadian Nissan Micra Cup cars #25216cars addedaddedB-Spec adds Canadian Nissan Micra Cup Car, 1598 cc, 2450 lbs minimum, with Micra Cup suspension kit allowed.
  • B-Spec Request updated Toyota Yaris Spec Lines #25483cars addedaddedB-Spec Toyota Yaris 12-18 added with 1491cc engine, 3.55 first gear, Bilstein B14 suspension, K&N intake allowed.
  • B-Spec Update wording of exhaust #26022wordingwordingB-Spec exhaust wording clarified: oxygen sensors must stay stock location, primary catalyst unmodifiable.

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. 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.