B-Spec vs GT2 vs STU vs P2 pace at Buttonwillow Raceway Park
Quickest here:B-Spec 2:09.353 Trenton Kramer, Cal Club 2026 qualifying · GT2 1:42.698 Tim Carroll, Cal Club 2026 qualifying · STU 1:50.913 Tony Rivera, Cal Club 2026 qualifying · P2 1:37.278 Tim Day Jr, Cal Club 2026 qualifying
B-SpecGT2STUP2solid race · dashed qualifying · slower is lower
B-SpecGT2STUP2solid race · dashed qualifying · each class's best lap as a share of B-Spec's at the same event (the reference class, changeable above); 100% is level, higher is quicker
Event
B-Spec
GT2
STU
P2
Qual best
Race best
Trap
Qual best
Race best
Trap
vs B-Spec
% of B-Spec
Qual best
Race best
Trap
vs B-Spec
% of B-Spec
Qual best
Race best
Trap
vs B-Spec
% of B-Spec
Cal Club 2026 CALCL262026-02-21
2:09.353Trenton 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%)
1:42.698Tim Carroll · fastest of 8 · top 5 within 7.4s-3.120s (-2.95%)
1:44.128Tim Carroll · fastest of 8 · top 5 within 4.3s-2.798s (-2.62%)
155.7Rocky Crocker+37.8 mph (+32.1%)
-25.788squal -26.655s
80.2%qual 79.4%
1:50.913Tony Rivera · fastest of 6 · top 5 within 14.1s-4.488s (-3.89%)
1:52.737Tony Rivera · fastest of 7 · top 5 within 7.7s-0.903s (-0.79%)
135.2Tony Rivera+21.8 mph (+19.3%)
-17.179squal -18.440s
86.8%qual 85.7%
1:37.278Tim Day Jr · only car
1:39.758Tim Day Jr · only car
155.4Tim Day Jr
-30.158squal -32.075s
76.8%qual 75.2%
49 rule changes (B-Spec: 24, GT2: 8, STU: 17)11 weight · 6 cars added · 4 induction · 3 tyres & wheels · 2 engine · 2 suspension & brakes · 1 aero · 19 wording · 1 other · C-Spec rear sway bars approved for Chevrolet Cruze, Dodge Dart, Ford Focus, Honda Civic, Mazda3i, Toyota Corolla with specified part numbers. · GT2 Porsche 911 SC gains option of 4.0L 4V engine at 2350 lbs or 4.0L 2V at 2275 lbs. · M3 E92 classified in GT2 with 3999cc V8, 35mm restrictor, 3300 lbs minimum weight. · B-Spec Chevrolet Sonic and Ford Fiesta, Honda Fit notes reorganized from individual allowances to approved parts lists; wording cleanup. · B-Spec: Sonic restrictors removed, Fit MT +25 lbs to 2550, Fit CVT restrictor removed, Mini Coopers restrictors increased 2-4 mm, Versa sedans -25 lbs to 2425, Versa/IA restrictors removed. · B-Spec Mazda2 10-14 cat-delete header swap removes 50 lb weight adder option, now Mazda Motorsports PN only. · GT2 adds Cadillac CTS, Chevrolet Impala/Malibu/Monte Carlo/SS, Dodge Intrepid, Ford Fusion/Taurus, Lincoln MKS, Pontiac G8/GTO/Grand Prix, Toyota Camry, and Gen late Model Stock Car bodies. · GT2 Mazda BP engine 1839cc classified with 46mm turbo inlet restrictor, 2250 lbs minimum weight. · 991.2 GT3 Cup throttle body restrictor increases from 65mm to 70mm; 997.2 loses 100 lbs to 2800; Corvette LS engines get larger restrictors across multiple displacements and model years; LS3 and LT1 weight reduced 100 lbs each to 3150. · STU Mazda MZR (LF, L3, L5) Turbo classified; Jack Spania Racing 70 mm intake manifold and Fab9 Tuning bottom-mount turbo kit approved. · STU 36mm restrictor allows 2830 lbs (up 10 lbs from 2820); 37mm allows 2980 lbs (down 5 lbs from 2985). · STU cars over 3150 lbs lose 275-tire option with 2% weight adder. · STU Honda K20 and K24 engines lose 2% minimum weight penalty. · B-Spec Honda Fit MT 07-08 allows Torque Solution Shifter Cable Bushing kit TS-SCB-506. · B-Spec Ford Fiesta Hatchback and Sedan gain 55 lbs to 2525; restrictors increase 1 mm. · B-Spec Hyundai Accent and Kia Rio remove Bilstein B8 shock 33-187112 rear suspension approval. · B-Spec Honda Fit MT (07-08) becomes Runoffs-eligible; previous three-weekend Super Tour requirement removed. · STU Honda K24 engine swap weight increases by 2% effective November 1, 2025. · B-Spec and C-Spec: asterisk removed from public road usage note in rule 9.1.10.D.9. · STU Lotus Elise SC and Exige SC weight reduced from 2450 to 2250 lbs. · B-Spec Honda Fit MT 09-14 two pedal shutdown may be disabled by cutting/de-pinning pin 42 BKSW at main ECU connector. · B-Spec Honda Fit MT 07-08 intake restricted to Injen SP1511 only, from any Cold Air Intake Package. · GT2 Porsche 911 Coupe & Targa may use 993 3.8 RSR rear deck lid or approved aftermarket reproductions. · STU-TCR tire width increases to 275 with weight adder raised from 100 to 150 pounds. · STL/STU Lotus weight reduced: Evora GT4 to 2700 lbs, Elise Cup R to 2250 lbs, Elise/Exige SC to 2450-2550 lbs. · STU 2.8-3.2L N/A engines now allow 245 max tire width; over 3150 lbs may run 275 with 2% weight penalty. · STU Mazda MZR may use Goodwin 61-2510 or Gato Performance 31972 intake manifold. · STU Honda JDM H23a added, 2259cc displacement, minimum weight per Chart, must meet ST engine regulations. · 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 allows Acuity Shifter Base Bushing Kit 1954. · B-Spec Honda Fit AT 09-14 adds Weapon R Intake 301-166-301 to approved parts. · B-Spec and C-Spec shift linkage/cables no longer prohibited from any modification; approved aftermarket bushings now permitted. · B-Spec Hyundai Accent Hatchback and Kia Rio Hatchback model year ranges corrected. · B-Spec 07-08 Honda Fit MT minimum weight increases 50 lbs, to 2450. · Honda Fit 07-08 MT and AT approved for Bilstein B14 kit 47172401 in B-Spec. · STU wheel width rules clarified: cars ≤2,850 lbs max 8 inches, cars >2,850 lbs max 9 inches. · STU Spec Line GT3U minimum weight reduced from plus 250 to plus 225 pounds; wheel and tire options clarified with weight adjustments. · B-Spec Honda Fit MT intake now limited to three models with 25lb adder; Mazda2 exhaust headers allowed with up to 50lb adder; Mini Coopers FPR increased 1-2 points; Nissan Versa sedans 40lbs lighter, Yaris models 50lbs lighter. · B-Spec Hyundai Accent and Toyota Yaris weight adjustments: ±25 lbs based on rear brake type. · B-Spec Hyundai Accent and Kia Rio (12-19) 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 alternative to 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. · GT2 Pontiac Fiero changes from FWD to RWD; hood bulge permitted for front engine relocation. · TA2 and STO OEM wings no longer exempt from rear wing height rule at roof peak. · STU BMW N54/N55 3.0L classified at Chart +3% minimum weight; N54 twin turbo not allowed. · STU Mini Cooper S SC supercharger pulley diameter reduced from 2.285 to 2.185. · STU Honda K20C1 Turbo I4 exempted from 3% DI weight adder in Spec Lines Table A. · STU GT3U minimum weight increases 150 to 250 pounds.showhide
B-Spec C-Spec Rear Sway Bars #39652wordingneutralC-Spec rear sway bars approved for Chevrolet Cruze, Dodge Dart, Ford Focus, Honda Civic, Mazda3i, Toyota Corolla with specified part numbers.
GT2 Allow Larger Air Cooled Engines in Porsche 911 GT2 #39249enginefasterGT2 Porsche 911 SC gains option of 4.0L 4V engine at 2350 lbs or 4.0L 2V at 2275 lbs.
GT2 Classify T1 BMW in GT2 #39408cars addedneutralM3 E92 classified in GT2 with 3999cc V8, 35mm restrictor, 3300 lbs minimum weight.
B-Spec Notes section cleanup #39062wordingneutralB-Spec Chevrolet Sonic and Ford Fiesta, Honda Fit notes reorganized from individual allowances to approved parts lists; wording cleanup.
B-Spec 2026 BOP Recommendations #39475other +25 lbsunclearB-Spec: Sonic restrictors removed, Fit MT +25 lbs to 2550, Fit CVT restrictor removed, Mini Coopers restrictors increased 2-4 mm, Versa sedans -25 lbs to 2425, Versa/IA restrictors removed.
GT2 Additional Body Options to Replace Older Stock Car Bodies #39086cars addedneutralGT2 adds Cadillac CTS, Chevrolet Impala/Malibu/Monte Carlo/SS, Dodge Intrepid, Ford Fusion/Taurus, Lincoln MKS, Pontiac G8/GTO/Grand Prix, Toyota Camry, and Gen late Model Stock Car bodies.
GT2 GT3 Turbo to GT2? #39365cars addedneutralGT2 Mazda BP engine 1839cc classified with 46mm turbo inlet restrictor, 2250 lbs minimum weight.
GT2 Tech Bulletins for GT2 and GT2-ST #39537induction -100 lbsslower991.2 GT3 Cup throttle body restrictor increases from 65mm to 70mm; 997.2 loses 100 lbs to 2800; Corvette LS engines get larger restrictors across multiple displacements and model years; LS3 and LT1 weight reduced 100 lbs each to 3150.
STU Request for Permission on Aftermarket Turbo Kit and Intake #39529cars addedfasterSTU Mazda MZR (LF, L3, L5) Turbo classified; Jack Spania Racing 70 mm intake manifold and Fab9 Tuning bottom-mount turbo kit approved.
STU Turbo Inlet Restrictor Table #38961inductionslowerSTU 36mm restrictor allows 2830 lbs (up 10 lbs from 2820); 37mm allows 2980 lbs (down 5 lbs from 2985).
STU 275 Tire Rule #38983tyres & wheelsslowerSTU cars over 3150 lbs lose 275-tire option with 2% weight adder.
STU STU Honda Engine weight penalty #39375weightfasterSTU Honda K20 and K24 engines lose 2% minimum weight penalty.
B-Spec Alternate Shift Cable Bushings and Rear Spring Seats #38472wordingneutralB-Spec Honda Fit MT 07-08 allows Torque Solution Shifter Cable Bushing kit TS-SCB-506.
B-Spec Fiesta BOP Adjustment #38847weight +55 lbsslowerB-Spec Ford Fiesta Hatchback and Sedan gain 55 lbs to 2525; restrictors increase 1 mm.
B-Spec Request to Remove Rear Shock From Spec Line Hyundai Accents/Kia #39017suspension & brakesunclearB-Spec Hyundai Accent and Kia Rio remove Bilstein B8 shock 33-187112 rear suspension approval.
B-Spec Update Honda Fit MT (07-08) Runoffs Eligibility #39060wordingfasterB-Spec Honda Fit MT (07-08) becomes Runoffs-eligible; previous three-weekend Super Tour requirement removed.
STU Non-Homologated Engine Swaps - Specifically K24A2 w/ Honda CRZ #38746weightslowerSTU Honda K24 engine swap weight increases by 2% effective November 1, 2025.
B-Spec Remove Asterisk from Rule 9 #38768wordingneutralB-Spec and C-Spec: asterisk removed from public road usage note in rule 9.1.10.D.9.
STU Lotus Weight Reduction E&O #38919weightfasterSTU Lotus Elise SC and Exige SC weight reduced from 2450 to 2250 lbs.
B-Spec Disabling 2 Pedal Shutdown #38354wordingneutralB-Spec Honda Fit MT 09-14 two pedal shutdown may be disabled by cutting/de-pinning pin 42 BKSW at main ECU connector.
B-Spec Update Honda Fit MT (07-08) Intake Allowance #38530inductionslowerB-Spec Honda Fit MT 07-08 intake restricted to Injen SP1511 only, from any Cold Air Intake Package.
GT2 Rear Deck Lid for Older Air-Cooled Porsche #38506wordingneutralGT2 Porsche 911 Coupe & Targa may use 993 3.8 RSR rear deck lid or approved aftermarket reproductions.
STU STU-TCR Adjustments #38723tyres & wheelsslowerSTU-TCR tire width increases to 275 with weight adder raised from 100 to 150 pounds.
STU Lotus Weight Reduction #38772weight -50 lbsfasterSTL/STU Lotus weight reduced: Evora GT4 to 2700 lbs, Elise Cup R to 2250 lbs, Elise/Exige SC to 2450-2550 lbs.
STU 2.8-3.2L N/A Engine Allowances #38007tyres & wheelsunclearSTU 2.8-3.2L N/A engines now allow 245 max tire width; over 3150 lbs may run 275 with 2% weight penalty.
STU 2006-2015 Mazda Miata Intake Manifold #38422wordingneutralSTU Mazda MZR may use Goodwin 61-2510 or Gato Performance 31972 intake manifold.
STU Requesting Approval of the JDM Honda h23a #38489cars addedneutralSTU Honda JDM H23a added, 2259cc displacement, minimum weight per Chart, must meet ST engine regulations.
B-Spec Add Sedan spec lines for Hyundai & Kia #37537cars addedneutralB-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. #38048wordingneutralB-Spec Honda Fit MT 09-14 allows Acuity Shifter Base Bushing Kit 1954.
B-Spec Add Weapon R Intake to Honda Fit MT (09-14) Spec Line #38306wordingneutralB-Spec Honda Fit AT 09-14 adds Weapon R Intake 301-166-301 to approved parts.
B-Spec Update Rule 46 #38307wordingneutralB-Spec and C-Spec shift linkage/cables no longer prohibited from any modification; approved aftermarket bushings now permitted.
B-Spec Correct Hyundai/Kia Model Years #37943wordingneutralB-Spec Hyundai Accent Hatchback and Kia Rio Hatchback model year ranges corrected.
B-Spec 07-08 Honda Fit MT Requests #37974weight +50 lbsslowerB-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 #38010wordingneutralHonda Fit 07-08 MT and AT approved for Bilstein B14 kit 47172401 in B-Spec.
STU Wheel Size Inconsistency #38018wordingneutralSTU wheel width rules clarified: cars ≤2,850 lbs max 8 inches, cars >2,850 lbs max 9 inches.
STU Table C: STU-GT3U Clarification #38268weightfasterSTU Spec Line GT3U minimum weight reduced from plus 250 to plus 225 pounds; wheel and tire options clarified with weight adjustments.
B-Spec 2025 BOP Recommendations #37520weightfasterB-Spec Honda Fit MT intake now limited to three models with 25lb adder; Mazda2 exhaust headers allowed with up to 50lb adder; Mini Coopers FPR increased 1-2 points; Nissan Versa sedans 40lbs lighter, Yaris models 50lbs lighter.
B-Spec Hyundai/Toyota Factory Rear Disc Models #37534wordingneutralB-Spec Hyundai Accent and Toyota Yaris weight adjustments: ±25 lbs based on rear brake type.
B-Spec Request to Update the Spec line for Hyundai Accent and Kia Rio #37880wordingneutralB-Spec Hyundai Accent and Kia Rio (12-19) allow Bilstein B14 kit #47167490 front shocks and BabyFace Fabrication sump extension #BF-HYU-PAN.
B-Spec Toyota Yaris Hatchback (12-18) rear disc brakes #37530suspension & brakesneutralB-Spec Toyota Yaris Hatchback 12-18 rear brakes now allow 10.2 inch disc alternative to 7.9 drum.
B-Spec Yaris Speed Sensor #37536wordingneutralB-Spec Toyota Yaris Hatchback and Sedan may now disconnect speed sensor.
B-Spec Set Expiration Date For Fiat 500 #37689wordingneutralB-Spec Fiat 500 (12-17) spec line expires 1/1/26 unless appeal filed.
GT2 Hood Bulge allowed #37000wordingunclearGT2 Pontiac Fiero changes from FWD to RWD; hood bulge permitted for front engine relocation.
GT2 OEM Wing Adjustment #37590aeroslowerTA2 and STO OEM wings no longer exempt from rear wing height rule at roof peak.
STU BMW N54/N55 Engine Allowance Follow Up #37447engineneutralSTU BMW N54/N55 3.0L classified at Chart +3% minimum weight; N54 twin turbo not allowed.
STU STU Mini Cooper pulley size clarification re: letter #36980 #37717inductionfasterSTU Mini Cooper S SC supercharger pulley diameter reduced from 2.285 to 2.185.
STU Question About a Weight Modifier #37782weightfasterSTU Honda K20C1 Turbo I4 exempted from 3% DI weight adder in Spec Lines Table A.
STU Increase Minimum Weight #37919weight +100 lbsslowerSTU GT3U minimum weight increases 150 to 250 pounds.
Cal Club 2025 CALCL252025-02-22
2:10.513Joseph Gersch · fastest of 4 · top 4 within 6.8s
2:10.054Thomas Lepper · fastest of 4 · top 4 within 7.4s
98.1Ali Naimi
1:45.818Brad McAllister · fastest of 6 · top 5 within 14.6s
1:46.926Brad McAllister · fastest of 6 · top 5 within 13.3s
117.9Guy Laidig
-23.128squal -24.695s
82.2%qual 81.1%
1:55.401Wilson Powell · fastest of 4 · top 4 within 8.7s
1:53.640Rylan Hazelton · fastest of 5 · top 5 within 8.0s
113.3Rylan Hazelton
-16.414squal -15.112s
87.4%qual 88.4%
360 earlier rule changes on record, in force before Cal Club 2025 (from 2019)61 cars added · 45 weight · 42 induction · 26 engine · 16 suspension & brakes · 14 tyres & wheels · 11 aero · 2 removed · 136 wording · 7 other · B-Spec Honda Fit AT, Fit CVT, Mazda2, Mini Cooper R50 MT and CVT, Toyota Yaris remove redundant notes language. · B-Spec removes Mini Cooper Countryman R60, Cooper Paceman R61, and two Nissan Versa generations effective 2/1/25. · B-Spec Nissan Micra Cup Car spec line expires 7/1/25 unless appeal submitted by 6/30/25. · GT2 STO aftermarket ABS weight penalty reduced from 100 lbs to 50 lbs. · B-Spec and C-Spec cars replace wheelbase spec with induction restrictor (mm) values, effective 2025-01-01. · B-Spec Hyundai Accent and Kia Rio approve Bilstein B8 shock 33-187112 for rear suspension use. · GT2 Panoz Esperante GTS adds 2013-2016 Ford EcoBoost Twin Turbo V-6 3496cc engine, 2600 lbs. · TA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof requirement. · GT2 Sunbeam Tiger gains Holly 650 cfm carburetor alternate options PN #80541-1 and #80541-2. · STU Audi 1.8T wagon deleted; Porsche 944 1800 weight to Chart, turbo inlet restrictor removed. · STU-GT3 reclassified as STU-GT3U effective January 1, 2026. · STU GT3 TCR gains 275-width tire option with 100 lb weight penalty, but not in A compound. · P2 2000cc Pinto engine car minimum weight set to 1335 lbs. · STL/STU: 90-05 Mazda Miata alternate front wheel hubs moved from General to specific part approval. · STU BMW N54/N55 turbo inlet restrictors now required per GCR definition; turbo swapping prohibited. · B-Spec Toyota/Scion IA Sedan 16-20 allows ST Suspension Kit 13275022, requires three Super Tour weekends and OBD-II data submission. · Honda Fit AT 07-08 B-Spec and C-Spec: rear sway bar Progress #62.1060 and any cold air intake package now allowed. · STU Mini Cooper S SC 1900 restricts to 2.565 diameter pulley; 2100 allows 2.285 diameter pulley. · B-Spec and C-Spec restricted to Goodyear Eagle RS/RS-R P205/50R15 and 225/45R17 tires respectively; Hankook tires removed; wet/dry mixing prohibited. · B-Spec Sonic restrictors increased to 5-6mm, Fit weight cut 50-25 lbs, Mini Cooper weight reduced 45 lbs, various restrictor adjustments. · B-Spec and C-Spec hood pins change from optional to recommended; factory release cable may be removed if pins used. · B-Spec and C-Spec Chevrolet Sonic and Cruze allow Babyface Fabrication brake caliper pistons. · STU RWD turbo cars no longer required to reduce restrictor by 1 mm from table. · B-Spec Honda Fit MT & CVT 15-19: cleaned up allowed parts notes, CVT gains Setrab transmission cooler option. · B-Spec Nissan Versa (09-11) spec line expires 1/1/2025 unless appeal filed by 12/1/2024. · B-Spec deletes redundant rule 25 in GCR Section 9.1.10.E. · B-Spec Hyundai Accent rear brakes corrected to 10.3 disc; Kia Rio rear brakes corrected to 10.3 disc. · GT2-ST allows aftermarket replacement differential housings if exact equivalents. · GT4 cars now permitted in GT2-ST with factory restrictor, must comply with 2012 STO rules, slicks allowed with 100-pound penalty. · B-Spec and C-Spec Chevrolet Sonic Bilstein B14 kit #47-171725 verified compatible, suspension wording clarified. · B-Spec Mazda2 and multiple Mini Cooper models eliminate redundant sway bar end link part number notes. · B-Spec Fiat 500 spec line changes from model year 2012–15 to 2012–17. · B-Spec Honda Fit 15-19 CVT weight increases to 2550 lbs, restrictor to 31mm. · B-Spec model descriptions standardized: trim levels and door count designations removed or replaced with body style wording. · B-Spec and C-Spec wheels must be same thickness spacers all four corners; wording clarified on offset and protrusion rules. · GT2-ST Acura NSX minimum weight raised to 3000 lbs, restrictor increased to 45mm TIR. · GT2-ST Corvette 14-19 LS2 restrictor increases from 78mm to 80mm flat plate. · P2 Spec ECU engine modifications clarified: oil system, ECU, and exhaust unrestricted only. · P2 FIA Group CN spec notes clarified: Series changed to Challenge, documentation requirement moved to online link. · B-Spec Honda Fit MT 2015-19 restrictor increases 30mm to 31mm, weight rises 2525 to 2550 lbs. · B-Spec and C-Spec now permit wheels of any offset if tire doesn't protrude beyond fender; spacers allowed with differing left-right offsets per axle. · B-Spec Mini Cooper Countryman R60, Paceman R61, and Nissan Versa 1797cc spec lines expire 1/1/2025 unless appealed by 12/1/2024. · B-Spec Honda Fit 07-08 loses 125 lbs to 2400; Versa S 2020+ loses 150 lbs to 2550; Yaris iA 16-20 loses 250 lbs to 2450. · B-Spec Honda Fit 07-08 rear sway bar part number changed to Progress #62.1060. · Chevrolet Corvette C8 (2020–) classified into GT2-ST with 6162cc displacement, 3300 lbs minimum weight, 71mm restrictor. · 2015 Mitjet ST added to GT2, must run per VTS specifications with complete FIA form CdM008. · STU Mini Cooper S SC: alternate LEAP OMICRON hood scoop LEP-OMICRON3 permitted. · STU BMW S54 B32 OEM now permits dry sump oiling system. · B-Spec and C-Spec eliminate case-by-case auxiliary transmission cooler approval requirement. · B-Spec Chevrolet Sonic 5dr Hatch MT allows aluminum radiator #ZZP-ZZ013. · B-Spec Honda Fit MT (09-14) and AT now split into separate spec lines with distinct allowances. · B-Spec Mazda 2 10-14 weight increases 70 lbs to 2350, cat-delete headers now permitted. · B-Spec Nissan Versa and Versa Note 2013-2019 now permit Hardrace HR-Q0146 19mm rear sway bar. · GT1, GT2, GT3, GTL, GTX rear spoiler maximum surface area limit of 295.0 square inches removed. · GT1/GT2/GT3/GTL/GTX Direct Injection now permitted if OE, using only OE pump, hoses, injectors. · GT2 Chevrolet Corvette 7011 OEM 7 liter weight reduced 150 lbs, to 3125 lbs. · GT2/3 Nissan, Mazda, Mitsubishi 4G93, QR25DE/DD, QE25DE/DD Direct Injection now permitted per 9.1.2.F.7.5.E. · STL and STU power steering rules clarified to permit electric-assisted and hydraulic-assisted steering systems. · B-Spec allows Hankook tires at regionals only through 6-30-2024; Goodyear only from 7-1-2024 for all events. · B-Spec Nissan Versa Note Hatchback (2013) minimum weight drops 60 lbs to 2490. · B-Spec and C-Spec ECU and data acquisition rules clarified: ECU must be unaltered OE, no device capable of altering ECU characteristics permitted; data acquisition expanded to allow tachometer, air-fuel ratio, cylinder head temperature sen… · GT2-ST Dodge Viper hybrid kit restrictor reduced from 50mm to 45mm flat plates. · P2 AMAC modified engine range clarified to 2008 and older stock engines only, restrictor 38mm, weight 1025 lbs. · P2 Suzuki GSX-R1000 07/08 engine crankcase may swap to GSX-S1000 16/19 part #11301-04840. · C-Spec Mazda 3i 10-13 third gear ratio corrected from 3.84 to 1.84. · C-Spec Dodge Dart 14-16 bore x stroke corrected to 88.0 x 82.0 mm, displacement to 1998 cc. · GTL spec lines moved to contiguous position with GT2 and GT3; GTA category and spec lines renumbered and moved behind GTL. · P2 Table 1 corrects engine date ranges and brand specifications for Stock and Modified engines across multiple car models. · B-Spec adds Goodyear Eagle RS dry and wet tires as options alongside Hankook; Hankook restricted to regional events from 2024. · GT2-ST Dodge Viper including Comp Coupe, ACR/ACR-X with VRL front fascia loses 100 lbs. · C-Spec adds Chevrolet Cruze, Ford Focus, Honda Civic, Mazda 3i, Toyota Corolla, VW Jetta; updates Dodge Dart, Mazda3s, Toyota Corolla specs. · GT2 Mazda 20B 3 rotor loses 220 lbs, to 2280, consolidating two spec lines. · B-Spec Hyundai Accent GS Hatchback restrictor plate increases from 39mm to 41mm. · B-Spec Hyundai Accent GS Hatchback model years corrected from 13–19 to 12–19. · GT2 BMW engines: 3.4L 6-cyl at 2575 lbs, 4.0L V8 at 2900 lbs, 4.5L V8 at 2950 lbs, 5.0L V8 at 3000 lbs; S54 with 97mm stroke permitted at 2800 lbs. · GT2 Corvette C7 restrictor increases from 73mm to 77mm flat plate, removing weight penalty. · Toyota GR Cup and GR86 Cup (2022-) newly classified in STU at 2700 lbs with 2387 cc engine. · B-Spec adds Hankook 200/580R15 Z217 tire option alongside 205/50R15 C51; C-Spec specifies 225/45R17. · B-Spec and C-Spec Chevrolet Sonic allows ZZP aluminum radiator #ZZP-ZZ013; Hatch MT restrictor increases to 34mm. · B-Spec and C-Spec bumper caps now allow positive fasteners like machine screws and T-nuts or rivet-nuts; self-drilling and sheet metal screws prohibited. · B-Spec and C-Spec allow CAN bus connections to data systems for monitoring only; systems must not send data. · B-Spec Ford Fiesta 5dr and 4dr lose 25 lbs each, to 2470 lbs minimum weight. · B-Spec Ford Fiesta 5dr and 4dr lose 25 lbs each to 2470; Honda Fit MT and CVT lose 50 lbs each to 2525; Mazda2 loses 50 lbs to 2280; Kia Rio restrictor increases from 39 to 41 mm; Mini Cooper variants gain 75 lbs to 2675 with larger restri… · C-Spec Mazda 3i Touring 2.0 Skyactive MT (12-13) newly classified with 155 hp, 148 lb-ft torque, 2900 lbs. · B-Spec minimum ride height set to 6 inches, C-Spec to 5½ inches. · B-Spec springs capped at 500# front and rear; C-Spec at 600# front, 800# rear; both may be strapped to body. · B-Spec wheels minimum weight set to 13 lbs, C-Spec to 17 lbs. · B-Spec and C-Spec allow metal threaded inserts in plastic intake manifolds for throttle body fasteners. · B-Spec and C-Spec wording clarified: CATEGORY to CATEGORIES, rules priority clarified for tire sizes, rim widths, springs, anti-roll bars, performance equipment. · 2009-2012 Porsche Cayman S classified in GT2, 3.4L, RWD, no PDK transmission allowed. · Fields Cardinal V8 classified in GT1 with Ford V8 engine, 4.9L displacement, 2100 lbs minimum weight. · P2 side body height requirement clarified: outermost surface between wheel openings must equal front axle centerline height. · P2 closed cockpit single seat cars now prohibited unless specifically allowed in Table 1. · GT2 Ginetta G56 GTA may now use Factory installed ProMap ECU Map. · P2 engine table wording updated; redundant effective date language removed. · P2 motorcycle engines: 2011+ Kawasaki restrictor reduced to 34mm, minimum weight raised to 1100 lbs; 2009+ other brands weight raised to 1100 lbs. · STU Mazda BP5A classified at 1839 cc maximum displacement, 2023-04-01. · B-Spec Mini Cooper R56 MT/AT and Clubman R55 fuel pressure regulator increased from 40mm to 41mm with OE catalyst. · B-Spec may use helper springs up to 500 pounds rate; tender springs now prohibited. · STU minimum weight chart updated: 2450cc to 2595lbs, 2600cc to 2710lbs. · B-Spec Honda Fit 09-14 Automatic now allows aftermarket exhaust/header; Manual unchanged. · GT2 Mazda 13B Street Port turbo changes from EFR 76/70 to BW7670 or Garrett G30-660 with 46mm TIR at 2280 lbs. · B-Spec Chevrolet Sonic and Honda Fit and Mini Cooper split into separate manual and automatic spec lines with distinct transmission ratios and final drives. · B-Spec tire rule adds Hankook 200/580R15 Z217 as alternative to 205/50R15 C51; no mixing wet and dry. · GT2 Porsche SOHC 2478/2681/2992 turbo sizes increase from 42mm to 44mm SIR to TIR. · GT2-ST Chevrolet Corvette 14-19 L76 5967 restrictor increases from 70 to 73 mm. · GT2 Toyota 4A-F and 4A-FE 1.6L DOHC 16V engines newly classified in spec line. · GT2 Mazda 13B Street/Bridge Port turbocharger changes from EFR 70/76 to 76/70, compressor from 42mm to 46mm. · GT2-ST BMW E36/46 spec line adds MA Shaw carbon/composite door offerings to Notes. · GT3 normally aspirated cars may use intake chokes instead of SIRs, fitted to each carburetor barrel, same size as required SIR. · GT3 2.0L 4-valve non-turbo engines may run unrestricted at 2060 lbs instead of with a choke restriction. · GT2 Porsche 991.1 TBR 70–72mm, 991.2 weight 3100–3000lbs TBR 65–67mm, ABS penalties removed; GT2-ST Corvette LS engines flat plate 75–78mm, LS7 65–68mm; Viper weights 3275–3125lbs. · Sebeco NP01-EVO and Elan NP01 Mazda 2.0L MZR added to P2, 1600 lb minimum, no restrictor required. · P2 Radical SR3/SR4/Cup/Club Sport/Pro-Sport/PR6 removes assisted shifting requirement across all spec lines. · P2 chassis rules clarified to allow composite materials in non-fully-composite construction; anti-intrusion panel attachment standardized; Stohr and converted F600 cars added with specific allowances. · Unable to summarize: the change to P2 Engine Table Spec Line B.1 is not detailed in the provided text. · GT2 TA2 and GTA throttle body part numbers updated to GM 90mm electronic #12570790 or Edelbrock 90mm mechanical #33869 or #3870. · GT2 Ginetta G56 GTA gains optional 18" x 9" and 18" x 10" wheels. · GT2/ST BMW E36/E46 now allows MAShaw body kit parts: wide body, bumpers, fenders, rockers, flairs. · B-Spec Honda Fit 15-19 weight drops 225 lbs to 2575 lbs. · GT2 Chevrolet Corvette L76 5967 restrictor increases from 73mm to 74mm. · GT taillights may now be original style or a panel graphic with functioning red LED brake lamps; wording change only. · Ginetta GTA G56 added to GT2 as spec car: 2600 lbs, 3.7L Ford V6 sealed, 6-speed Quaife sequential. · B-Spec Mazda2 10-14 rear sway bar now allows part 0000-04-2203-RR or 0000-04-2312. · GT2 BMW E36/E46 carbon roof and door suppliers added to notes: Lang Racing, 2M Automotive, Flossmann, MA Shaw. · GT2-ST BMW E46 M3, E36, Z3, 5000cc V8 can use 95mm S54 crankshaft at +150 lbs. · Audi R8 GT4 classified to GT2 with 5.2L displacement, 3000 lbs minimum weight, per factory specs restrictor. · STU Mazda 13B Turbo classified, streetport only, stock turbos prohibited, alternatives allowed. · STU OEM louver vents now exempt from vent count and 200 square inch allowance. · STU 2400cc non-4-valve engines gain 9% base weight reduction; DI turbo prep limits removed. · STU normally-aspirated 2976–3200 cc single-throttle engines lose 10% base engine weight reduction. · ST redundant language removed from balance shaft and pulley modification rules. · B-Spec Hyundai Accent GS and Kia Rio restrictor increased from 36mm to 39mm flat plate. · GT2 shock absorber attachment points clarified as moveable; wording correction only. · GT2 Porsche 104.0 x 88.0 engine weight increases from 1950 to 2090 lbs; 2V variants may use Borg Warner EFR 76/70 42mm turbo. · P2 chassis construction rules clarified: fully composite or partially composite requiring composite for mobility allowed; partial composite must roll without composite parts. · P2 classification wording cleaned up in GCR section 9.1.8.C and Contents. · STU cars that qualified for 9 inch wheels in 2021 may continue through 2022 only. · STU splitter definition clarified: must be single-plane with no vertical deviations, attached to lowest front point. · P2 Oldsmobile cam rules clarify aftermarket manufacturer requirements; wording only. · STU BMW S52B32 minimum weight drops 90 lbs to 3110; max displacement cut to 3152 cc. · STU BMW S50B32 Euro classified at 3201 cc displacement, 3300 lbs minimum weight. · ST engine swap origin country requirement changes from North America to the United States for case-by-case approval. · STU Honda CRX (84-91) and Civic Del Sol (93-97) ineligible for front wheel drive weight reductions. · STU vehicles at or over 2950 lbs base weight may use 9 inch wide wheels instead of 8.0 inch maximum. · STU minimum weights reduced: 2450cc to 2596 lbs, 2500cc to 2635 lbs, 2550cc to 2675 lbs. · B-Spec allows springs strapped to body for rebound control; removes requirement for OEM or kit bump stops. · B-Spec strut tower modifications permitted for camber adjustment only, limited to 1.75 degrees. · B-Spec Mazda2 10-14 undertray part numbers corrected to DO8C-56-110A, DO8C-56-311, DO7A-56-321. · Ginetta G40 classified in GT2 with Mazda MZR/L5-VE engine, 2488cc or 2399cc, 1950 lbs base weight. · Toyota Supra GT4 added to GT2-ST: 3000cc, 3000 lbs minimum, factory restrictor. · GT2 Porsche 944/924 may use ERC 76/70 Turbo instead of Jayco super 50. · P2 adds Beasley B2 spec line with 1350 lbs, Mazda 12A, 40.5mm venturi, 16.5in wing. · P2 wing specs correct terminology from 'cord' to 'chord' for 16.5in single or dual element wings. · P2 Converted F5 cars reclassified as Converted F500 cars; suspension must comply with F500 requirements, minimum width 55 inches. · STU normally aspirated engines: minimum weights reduced up to 310 lbs; single throttle body weight reduction removed. · STU Audi A4 1.8T minimum weight fixed at 3050 lbs, VF30 turbo with 35mm restrictor now required only. · STL and STU Improved Touring vehicles must conform to 9.1.4 Tires & Wheels requirements. · B-Spec Nissan Versa S 2020- classified at 2700 lbs with 38mm restrictor, 1598cc engine. · Toyota/Scion IA Sedan (2016-2020) classified for B-Spec at 2700 lbs with 38mm FPR. · B-Spec Mazda 2 (10-14) replaces Bilstein B14 suspension kit with Powerflex rear bushings; adds radiator, exhaust headers, undertray. · GT2 Porsche Cayman 05-15 turbo restrictor increases from 70mm to 75mm. · P2 motorcycle engines increase to 1505cc max, two-stroke to 1205cc max; automotive engines gain 50 lbs minimum weight to 1350. · STU engines may delete balance shafts and plug openings; alternate pulleys allowed for timing belt or chain operation only. · STU hood vents allowed to include louvers within 200 sq. inch area. · 2007-2008 Honda Fit automatic added to B-Spec at 2525 lbs with 1499 cc engine. · GT2 Porsche Cayman 05-15 uses Throttle Body Restrictor instead of Flat Plate Restrictor at 2700 lbs. · P2 Control Area definition narrowed; aerodynamic attachments and vertical structures like turning vanes now prohibited. · STU adds Honda K23 with 2354cc displacement and minimum weight per chart, K24 block allowed with K23 internals and head. · STU Honda K23 internals rule relaxed to require only K23 crankshaft, allowing other internal modifications. · STL and STU piston engines clarified: intake manifold and cylinder head porting remains free. · P2 Engine Table Spec Line B.1 changed effective 1-1-22, details not provided in excerpt. · P2 Control Area definition clarified: floor extensions and aerodynamic attachments on bottom or top side now explicitly included. · B-Spec upper strut slotted plates no longer require manufacturer's original bolt holes or serve as reinforcement. · GT2 Mazda 13B street port adds EFR 70/76 turbo with 42mm restrictor at 2280 lbs. · GT3 Fun Cup Beetle EVO3 classified with 1984 cc sealed SOHC engine, 2060 lbs minimum weight. · B-Spec upper strut slotted plates no longer must use manufacturer's original bolt holes. · GT2 Dodge Viper Comp Coupe ACR/ACR-X loses 100 lbs minimum weight to 3275. · P2 CN Honda K20A-FD2 engine rebuild rules clarified: machining prohibition replaced with specific restrictions on balancing, porting, polishing, valve jobs, cylinder honing. · 04-06 World Challenge Pontiac GTO added to GT2-ST: 6062 cc, 3000 lbs minimum, unrestricted. · GTA part numbers updated: 0-80541-1 to 0-80541-2 in two sections and 6010 to 6014X in TA2 Appendix. · Grullon GT with 2.0L K20 moved from GTX to GT2-ST, minimum weight 2350 lbs, unrestricted. · Converted F5 cars in P2 minimum width reduced to 55 inches from F5 spec. · P2 clarifies minimum body width requirement between front and rear wheels for Ralt RT40, RT41, Swift 008, 014. · B-Spec Mazda2 10-14 allows header PN 0000-06-2410 with 70 lb weight penalty. · GT2-ST Porsche Cayman restrictor increases from 65mm to 75mm flat plate at 2700 lbs. · GT2 Dodge Viper including Comp Coupe, ACR/ACR-X minimum weight reduced 100 lbs to 3275 in VRL Spec. · TA2 minimum weight set to 2930 lbs with free tire make and size. · STU fender flare wording clarified: exterior contour of any wheel opening may not change opening size, location or shape from side view. · STU Mazda 12A Bridge Port Miata weight reduced from 2550 lbs to 2350 lbs. · B-Spec Honda Fit and Mini Cooper models gain alternate transmission ratios and final drives to allow Setrab 50-119-7612 cooler. · B-Spec Honda Fit 2007-08 classified with 1499cc displacement, 2450mm wheelbase, 2525 lbs minimum weight. · B-Spec Ford Fiesta 5dr Hatchback allowed Eibach rear sway bar #35143.312 or #35143.320. · B-Spec restrictor range changes from 0.060" ±0.005" to 0.050"-0.079". · B-Spec rear window wipers and wiper motor removal now allowed. · P2 tonneau covers now allowed to meet minimum dimensions; equipment attachment requirements clarified. · P2 multiple chassis models remove effective dates from Table 1 specifications. · P2 engines limited to 4 valves per cylinder maximum across all three spec lines. · STU fender flare rules clarified: maximum 2 inches, must cover tire contact patch from above, cannot alter body configuration or wheel opening geometry. · B-Spec Mini R60 and R61 allow 4-lug hub conversion with specified bearings and brake rotors. · B-Spec Mazda2 10-14 header replacement allowed, minimum weight increases 2330 to 2380 lbs. · B-Spec Honda Fit model years expand from 09-12 to 09-14. · B-Spec Hyundai Accent GS and Kia Rio restrictor reduced from 40mm to 36mm flat plate. · B-Spec must use Hankook P205/50ZR15 Z214 C51 or Z217 rain tyres for SCCA Majors, Super Tour, Runoffs. · GT2 Sunbeam SBF 302 engine firing order option now explicitly allows Boss 302 variant. · STU Honda S2000 allows F20/F22 K24 crankshaft with chart weight for achieved displacement. · ST oil coolers and filters now explicitly allowed to be added or substituted; wording clarifies existing permissions. · B-Spec tire rules clarified: Hankook Z214 dry and Z217 rain required at Majors/Super Tour/Runoffs after 6-1-2021; regional racing allows any DOT race tire through 2021. · B-Spec restrictor thickness set to 0.060 inches plus or minus 0.005 inches. · GT2-ST Corvette (-2019) LS2 and L76 5967cc gain 100 lbs minimum weight to 3100; 6162cc variants gain 50–100 lbs; 7011 gains 100–50 lbs; L76 restrictor opens 70 to 73 mm. · GT2 rear engine opening location requirement removed. · GT2 Ford Mustang/Thunderbird Boss 302 firing order now optional from later SBF 302 versions. · P2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front and 14-15 rear wheel width. · STL/STU 90-05 Mazda Miata gains approval for Mazda Motorsports Development alternate front wheel hubs. · B-Spec Hyundai Accent GS Hatchback 2013-2019 classified at 2525 lbs with 40mm flat plate restrictor. · B-Spec Mini Cooper Countryman R60 and Paceman R61 production years corrected from 11-13 to 11-16. · B-Spec Toyota Yaris Hatch model year spans corrected from 07-12 to 07-11 and 12-18 added. · B-Spec Mini Cooper all models ride height minimum 5 inches measured from metal under door rocker molding. · B-Spec allows removal or material modification of metal or plastic brake dust shields. · B-Spec Mini Cooper Clubman R55 11-15 permitted OBX header with 40mm flat plate restrictor. · GT2 ABS braking systems now allowed if shown on individual Spec Line. · GT2 Corvette C6 and C7 spec lines clarified and split; C7 LS2/L76/LS3/LT1/LS7 weights increased 100–150 lbs effective 3/1/2021. · ST cars may relocate ABS actuation hardware and wiring anywhere in engine compartment. · STU Porsche PDK automatic transmission limited to 8 forward speeds instead of torque converter restriction. · STU Mazda 13B Street Port 2400 removes choke location restriction, allows auto-type 2bbl with dual-Y manifold. · STU driveshaft and half-shaft materials change from OEM-type to steel or aluminum. · GT2 Ford Mustang/Thunderbird Boss 302 firing order becomes unrestricted. · GT2 BMW E46 M3 weight reduced from 2600 to 2500 lbs. · STU Mazda 13B Street Port classified at 2400 lbs minimum weight, replacing peripheral and bridge port variants. · B-Spec: Bilstein B14 suspension kits removed from all car spec lines; clarified B14 shock or strut use requires CRB approval of mounting adaptors. · B-Spec removes Chevrolet Sonic 12-19, clarifies Toyota Yaris Hatch 07-12 and Sedan 07-12. · GT2 Chrysler/Dodge/Plymouth 2429cc DOHC engine classified at 1950 lbs, unrestricted fuel induction. · P2 Honda K20A-FD2 intake restrictor reduced from 55mm to 50mm, making cars faster. · ST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch. · GT2 stock car bodies removal rescinded; 1997-current year commercially available stock car bodies remain allowed. · GT2 Appendix L renumbering eliminates sections .17 through .19 after 4.8.4.2.10.3.6. · GT2 TA2 wing width maximum set to 65 -5/16 inches, previously undefined. · B-Spec Mini Cooper R56 40mm flat plate restrictor requirement removed, suspension and header parts now allowed. · GT1, GT2, GT3, GTL, GTX now permit turbocharging/supercharging if listed on spec line. · GT2 Chevrolet Corvette -2019 LS1/LS6 allows DORMAN part # 615-900 alternate intake manifold. · GT2 Porsche 997.2 GT3 Cup minimum weight drops to 2900 lbs. · P2 rear wing requirements clarified: standard wing 6×12 inches, end plates 14-inch square; alternate 110cm width wing 9×18 inches, end plates 14×18 inches. · STU fender flare rules reworded: up to 2" per corner allowed with 1% weight penalty total. · GT2 BMW E46 M3, E36, Z3, and 5000cc V8 gain Trans Am SGT spec allowance: regular shifter 3000 lbs., paddle shifter plus 150 lbs. · GT2 allows up to four hood/fender louvered panels, max 600 sq inches total, min five slots each, mounted in front of windscreen. · STL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis adjustments. · STL and STU rear wing rules clarify that wicker is a Gurney flap; no performance change. · TA2 Gurney flap wording clarified: terminology standardized to 'Gurney flap', height limits and thickness specifications remain 0.50 inch / 0.625 inch or 0.375 inch / 0.0625 inch depending on configuration. · STO rear wing wording clarified: 'wicker' changed to 'Gurney flap' in maximum chord and mounting height rules. · GT classes clarify Gurney flap wording, replacing wickerbill/tab terminology with flap; specifications unchanged. · STU request for alternate intake manifold denied; no rule change issued. · GT3 and STU add Borg-Warner EFR6258 to approved turbocharger list. · STU large displacement turbo engines limited by GCR turbo list; non-turbo trim suggested as more competitive. · STU sequential shifters referred to Board of Directors for approval; no change implemented yet. · B-Spec wheelbase measurements converted from inches to millimeters for consistency across all cars. · GT2 Dodge Viper 8400 OEM minimum weight drops 50 lbs to 3275. · GT2 Chevrolet Corvette -2019 OEM minimum weight cut 50 lbs to 3275. · Elan NP01 classified in P2 Table 1 as Spec Line car with 2000cc displacement and P2 Engine Table restrictor. · STU Mazda 13B Bridge Port and Street Port engines added with 2550 and 2250 lbs minimum weights respectively. · B-Spec Chevrolet Sonic 5dr Hatch and 4dr Sedan allow Setrab transmission cooler for automatic-equipped cars. · B-Spec: multiple models allow specific suspension kits and damper assemblies. · B-Spec sunroof retention wording removed, simplifying rules. · B-Spec Ford Fiesta 5dr gets 36mm restrictor, 4dr gets 34mm, Honda Fit 09-12 loses 25 lbs to 2525, Fit 15-20 restrictor reduced 32mm to 30mm, Mini Cooper 07-10 gets 40mm restrictor. · GT2 Corvette LS6 may reduce weight by 50 lbs. · P2 Enterprises Sports Racer adds 55mm flat plate intake restrictor Part # WM303013 as alternative to SIR. · GT2 Panoz GT-S now allowed to use TA2 Choice Engine with any 5-speed H-pattern transmission. · GT2-ST Corvette LS2 restrictor increases from 70mm to 75mm flat plate. · GT2-ST Corvette L76 added: 5967cc, 3000 lbs minimum, 70mm flat plate restrictor. · P2 Enterprise Sports Racer 2.3L engine now requires SIR or Flat Plate restrictor sized in 0.5mm increments. · STU Honda S2000 adds HKS Supercharger kits 12001-AH006 and 12001-AH010 as allowed. · STU Lotus Elise Cup R and SC models, plus Exige SC, gain 100–200 lbs minimum weight. · STU Volkswagen GTI/GLI MK5 and Jetta Mk4 may install turbo inlet restrictor in OEM turbo inlet housing. · STU Honda K20C1 Turbo I4 restrictor reduces from 36mm to 35mm. · STU GM Ecotech LNF now allowed with turbo removed or with LE5 head and intake manifold, meeting STL specs. · STU Porsche 944 now permits VW/Audi 1.8L and 2.0L turbo engines as alternates. · B-Spec Sonic extended to 2019, Fiat 500 limited to 2015, Fiesta models extended to 2019, Fit expanded to 2015-2019. · B-Spec Mini Cooper R50, R55, R58, R60, R61 models newly classified at 2545–2625 lbs with 40mm restrictor for 12+ models. · B-Spec fog lamps must now be removed and holes completely covered, reversing prior allowance. · B-Spec Chevrolet Sonic 4dr Sedan (12-19) added at 2650 lbs with 32mm flat plate restrictor. · GT2 Porsche 991.2 GT3 Cup Car engine displacement increases from 3.8L to 4.0L. · P2 fly-by-wire throttle control wording clarified: stock ECUs with drive-by-wire must activate original throttle shaft mechanism. · STU vehicles over 2951 lbs base weight may use 9 inch wide wheels, up from 2950 lbs. · STU turbocharged engines now use base weight instead of minimum weight, with 3% DI increase applied to base weight. · B-Spec now permits automatic and CVT transmissions on all legal cars meeting spec line. · B-Spec automatic transmissions may use auxiliary coolers on case-by-case basis with part number approval. · GT1, GT2, GT3, GTL, GTX may omit windshield clips if factory glass is bonded per original specifications. · GT2 Chevrolet SS replaces Dodge Charger; all stock car bodies removed from GT2 in 2021. · Toyota Yaris Sedan 2007- added to B-Spec at 2400 lbs with 1491cc engine. · B-Spec adds 2011-2016 Ford Fiesta 4dr Sedan, 1596cc, 2495 lbs minimum weight. · B-Spec Kia Rio 5-door/LX years expanded to 2012-2019. · B-Spec Mazda2 (10-14) allows specific suspension, intake, exhaust, and bushing parts; removes air duct Mz26-117-33100. · Factory Five Type 65 Coupe R with Ford 302/351 or 5.0/5.2L NA added to GTX-MISC at 2600 lbs. · 991.2 GT3 Cup Car classified in GT2 at 3100 lbs with 63mm throttle body restrictor. · GT2 Acura NSX minimum weight reduced from 3000 to 2700 lbs. · GT2 Porsche 991.1 GT3 Cup restrictor size increases from 67 mm to 70 mm. · GT2 Porsche 996/997.1 GT3 Cup minimum weight reduced 100 lbs, to 2800. · GT2/ST Corvette -2019 5967cc restrictor reduced from 75 mm to 70 mm. · P2 adds BMW to motorcycle-based engine options in 4-cycle line alongside Kawasaki, Suzuki, Yamaha, Honda. · B-Spec Mini Cooper production years corrected to 2011-13. · STU cars with manual OEM throttle bodies may convert to OEM electronic throttle body of same inner diameter. · B-Spec Mazda 2, Fiat 500, 2007-10 Mini Cooper permitted to replace primary cat/exhaust manifold with approved header. · B-Spec removes year-specific eligibility and twelve-year competition window wording. · B-Spec Honda Fit model year expanded to include 2013, now covers 2009–2013. · P2 Honda K20A-FD2 non-composite chassis must use 55mm flat plate intake restrictor at 1500 lbs minimum weight. · P2 motorcycle engines: Stock restrictor 36.5mm to 35mm, modified 37.5mm to 34mm; B.5 restrictor 37.5mm to 33mm. All weights increase 25 lbs. · STU wing assembly wording corrected: no part higher than roof height. · B-Spec 2007-10 Mini Cooper gains OBX header part #10-2101-2S as permitted E&O. · GT2 TA2 cars must weigh minimum 2930 lbs per current Trans Am rules or prior Appendix L. · P2 cars limited to power application on maximum two wheels, effective 2019-07-01. · STU Nissan SR20DET removes -2mm penalty in Table B. · STU alternate intake manifolds now allowed case-by-case instead of prohibited. · P2 Enterprise minimum weight increases to 1375 lbs; peak horsepower of sealed ESR engine reduced per CRB specification. · GT2 Toyota Supra 3SGTE newly classified at 2900 lbs minimum weight, 43mm restrictor. · Acura NSX All Years classified to GT2-ST: 3.5L turbo, 3000 lbs minimum, 43mm restrictor. · GT2 TA2 minimum weight increases from 2830 to 2930 pounds. · STU aftermarket side skirts must meet 3-inch ride height, no openings except jacks or side exhaust, no wider than fascias, not higher than door bottom, no chassis reinforcement. · STU fender flare wording clarified: each fender may be flared up to 2" for tire clearance with 1% weight penalty. · GT2 BMW E36/E46 4.5L V8 classified at 2950 lbs minimum weight. · GTX tube frame cars gain fuel injection with 90mm maximum throttle body size. · Ligier JS2 R classified in GTX, no performance parameters specified in filing. · STL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld. · GT2 Ford Mustang 5.2L classified at 3300 lbs minimum with 82mm single throttle body restrictor. · GT1 and GT2/GT3/LITE ride height requirements removed from GCR sections 9.1.2.D.5.a.1 and 9.1.2.F.7.b. · STU Mazda 13B Bridge Port may use ELITE ROTARY SHOP FD V2.0 intake manifold instead of stock. · STU Mazda MZR LF/L3/L5 may use Goodwin Part #61-2510 intake manifold with stock or Acura throttle body. · STU suspension rules clarified: alternate components from same manufacturer moved from section E to section D. · STU Honda/Acura B20 classified at 1973 cc, now permits VTEC B16 or B18 cylinder head and intake manifold. · STU flared fenders up to 2" with 1% weight penalty moved from base to Advanced Aero rules. · TCA Honda Civic Si (2017-) must run 37mm TIR maximum as of June 1, 2019. · STU BMW S54B32 OEM reclassified from E46 designation, 3246 cc, 3300 lbs minimum weight. · B-Spec added to GCR 9.3.26 fuel cell exception list; stock fuel tank permitted. · GT2 Porsche Cayman model years change from 05-11 to 05-15. · GT2 Porsche Cayman adds 4.0L engine with 65mm flat plate restrictor at 2700 lbs minimum weight. · P2 stock engine restrictor shrinks to 35.0mm and weight rises to 1025 lbs; modified engine restrictor to 34.0mm, weight to 1125 lbs; line B.5 restrictor to 33.0mm, weight to 1185 lbs. · P2 Line A.1 restrictor reduced from 40mm to 38mm. · Honda Civic Si 2017- classified STU at 1500cc, 2800 lbs minimum with OEM engine and bodywork. · STU BMW E46 S54 OEM 3246cc added at 3300 lbs minimum weight, no Super Touring allowances. · STU Mazda 13B and 13B Bridge Port may use RE or REW housings and intake with turbo removed. · STU Honda K24 may use intake part #s 17100-RRB-A00 or 17100-PRB-A10. · STU Mazda 12A Bridge Port engine classified at 2550 lbs minimum weight with specified carburetor induction options. · STU World Challenge car weight calculation method removed; new basis unclear from text provided. · STU AWD cars no longer required to reduce restrictor 1 mm from table. · STU rear wing maximum cord length set to 12 inches, end plates to 72.0 square inches each. · Canadian Nissan Micra Cup Car classified in B-Spec at 2450 lbs with 1598cc engine, Micra Cup suspension kit allowed. · Toyota Yaris (12-18) newly classified in B-Spec with 1491cc engine, 2400 lbs minimum weight, specified suspension and intake allowed. · B-Spec exhaust system wording clarified: OEM or exact replacement catalysts permitted, stock oxygen sensors required, primary converter unmodified. · GT2 BMW E46 M3, E36, Z3, and 5000cc V8 now permit Flossman body kit. · GT2 TA2 cars: wheels cost cap drops to $175 each, carbon fiber allowed on rear wing, engine setback maximum 21.75 inches (A-F) or 24 inches (G), various nomenclature and clarification updates. · BMW 1 Series E82 classified into GT2 with N52B30 engine, 2996 cc, 2140 lbs minimum weight. · GT2 Porsche Cayman 05-11 base weight drops 75 lbs to 2800; adds STO/X51 motor notes. · GT2 Ford Mustang 05- with 5.2L Aluminator engine classified: 3400 lbs minimum weight, 2×41mm flat plate restrictor. · GT2 Porsche 996/997.1 GT3 Cup adds 3.6L displacement and 2900 lbs minimum weight; removes aftermarket exhaust header allowance for 996. · GT2 Ford Mustang FP350S minimum weight reduced 100 lbs, to 3400. · GT2 Ford Mustang 05- EcoBoost classified: 3500cc, 3200 lbs minimum, 41mm restrictor. · GT2 Mazda RX7 Downing GTS body kit allowed without 75 lbs. weight penalty. · GTX FIA GT3: Audi R8 40mm restrictor 2900 lbs, BMW Z4 70mm 2800 lbs, Ferrari 488 35mm restrictor 3025 lbs classified. · P2 Spec Line cars now allow 1345cc Hayabusa stock engines at 1050 lbs with 30mm restrictor. · P2 Group CN Honda K20A-FD2 55mm restrictor implementation delayed from 1/1/2019 to 3/1/2019. · P2 Honda K20A-FD2 in CN chassis must use stock intake manifold with 64mm throttle body and 55mm restrictor at 1500 lbs minimum weight. · STU Honda K20C1 Turbo I4 1996cc added at 3025 lbs minimum weight with 36mm TIR.showhide
B-Spec Remove Redundant Language from Notes Sections #37337wordingneutralB-Spec Honda Fit AT, Fit CVT, Mazda2, Mini Cooper R50 MT and CVT, Toyota Yaris remove redundant notes language.
B-Spec Expire designated spec lines #37517removedneutralB-Spec removes Mini Cooper Countryman R60, Cooper Paceman R61, and two Nissan Versa generations effective 2/1/25.
B-Spec Set expiration date for Nissan Micra Cup Cars (Canadian) #37519wordingneutralB-Spec Nissan Micra Cup Car spec line expires 7/1/25 unless appeal submitted by 6/30/25.
GT2 GT2/ST - Remove Aftermarket/Racing ABS penalty #36538weightfasterGT2 STO aftermarket ABS weight penalty reduced from 100 lbs to 50 lbs.
B-Spec Remove wheelbase from spec lines and replace with Restrictor #36074inductionunclearB-Spec and C-Spec cars replace wheelbase spec with induction restrictor (mm) values, effective 2025-01-01.
B-Spec Bilstein Rear Shock Request for Hyundai Accent/Kia Rio #36965suspension & brakesneutralB-Spec Hyundai Accent and Kia Rio approve Bilstein B8 shock 33-187112 for rear suspension use.
STU Audi 1.8t Wagon STU Table B #36685cars addedfasterSTU Audi 1.8T wagon deleted; Porsche 944 1800 weight to Chart, turbo inlet restrictor removed.
STU Merger GT3 to STU #37486wordingneutralSTU-GT3 reclassified as STU-GT3U effective January 1, 2026.
STU GT3 TCR Tire allowance #37494tyres & wheelsslowerSTU GT3 TCR gains 275-width tire option with 100 lb weight penalty, but not in A compound.
P2 2000 cc Pinto Engine Car Weight #37187weightslowerP2 2000cc Pinto engine car minimum weight set to 1335 lbs.
STU Request to Remove Miata Hubs from General category #37138wordingneutralSTL/STU: 90-05 Mazda Miata alternate front wheel hubs moved from General to specific part approval.
STU BMW N54/N55 Engine Allowance #37146inductionslowerSTU BMW N54/N55 turbo inlet restrictors now required per GCR definition; turbo swapping prohibited.
B-Spec Scion IA/Toyota Yaris/Mazda 2 DY chassis suspension #35780suspension & brakesunclearB-Spec Toyota/Scion IA Sedan 16-20 allows ST Suspension Kit 13275022, requires three Super Tour weekends and OBD-II data submission.
B-Spec Clean up 07-08 Honda Fit AT Notes Section #36542suspension & brakesfasterHonda Fit AT 07-08 B-Spec and C-Spec: rear sway bar Progress #62.1060 and any cold air intake package now allowed.
STU R53 15% Pulley Request #36980inductionslowerSTU Mini Cooper S SC 1900 restricts to 2.565 diameter pulley; 2100 allows 2.285 diameter pulley.
B-Spec Update Tire Rules #35984tyres & wheelsneutralB-Spec and C-Spec restricted to Goodyear Eagle RS/RS-R P205/50R15 and 225/45R17 tires respectively; Hankook tires removed; wet/dry mixing prohibited.
B-Spec BOP help for the automatic B-Specs #36161weight -50 lbsfasterB-Spec Sonic restrictors increased to 5-6mm, Fit weight cut 50-25 lbs, Mini Cooper weight reduced 45 lbs, various restrictor adjustments.
B-Spec Require hood pins #36233wordingneutralB-Spec and C-Spec hood pins change from optional to recommended; factory release cable may be removed if pins used.
B-Spec Sonic Caliper Pistons #36238wordingneutralB-Spec and C-Spec Chevrolet Sonic and Cruze allow Babyface Fabrication brake caliper pistons.
STU RWD Turbo Disadvantage #36255inductionfasterSTU RWD turbo cars no longer required to reduce restrictor by 1 mm from table.
B-Spec Clean up (15-19) Honda Fit MT & CVT Notes Sections #36068wordingneutralB-Spec Honda Fit MT & CVT 15-19: cleaned up allowed parts notes, CVT gains Setrab transmission cooler option.
B-Spec Set expiration date for Nissan Versa (09-11) #36069wordingneutralB-Spec Nissan Versa (09-11) spec line expires 1/1/2025 unless appeal filed by 12/1/2024.
B-Spec Correct error for rear brakes of Hyundai/Kia #36174wordingneutralB-Spec Hyundai Accent rear brakes corrected to 10.3 disc; Kia Rio rear brakes corrected to 10.3 disc.
GT2 GT4 cars may run in GT2-ST #36235cars addedneutralGT4 cars now permitted in GT2-ST with factory restrictor, must comply with 2012 STO rules, slicks allowed with 100-pound penalty.
B-Spec Add B14 Kit Part # to Sonic Spec line In #35969wordingneutralB-Spec and C-Spec Chevrolet Sonic Bilstein B14 kit #47-171725 verified compatible, suspension wording clarified.
B-Spec Eliminate redundant sway bar end link part #s from notes In #35970wordingneutralB-Spec Mazda2 and multiple Mini Cooper models eliminate redundant sway bar end link part number notes.
B-Spec Update Fiat 500 Spec line In #35990wordingneutralB-Spec Fiat 500 spec line changes from model year 2012–15 to 2012–17.
B-Spec Update (15-19) Honda Fit #36067weight +25 lbsslowerB-Spec Honda Fit 15-19 CVT weight increases to 2550 lbs, restrictor to 31mm.
B-Spec Delete trim levels/update language for spec lines #35746wordingneutralB-Spec model descriptions standardized: trim levels and door count designations removed or replaced with body style wording.
B-Spec Wheel Rules #36066wordingneutralB-Spec and C-Spec wheels must be same thickness spacers all four corners; wording clarified on offset and protrusion rules.
GT2 Request for Spec Line 1010 Reconsideration #35009weight +300 lbsslowerGT2-ST Acura NSX minimum weight raised to 3000 lbs, restrictor increased to 45mm TIR.
GT2 Request to Eliminate the FPR from the Corvette (-2013) with LS2 #35878inductionfasterGT2-ST Corvette 14-19 LS2 restrictor increases from 78mm to 80mm flat plate.
P2 E&O - Correct FIA Group CN spec line notes #35900wordingneutralP2 FIA Group CN spec notes clarified: Series changed to Challenge, documentation requirement moved to online link.
B-Spec Change restrictor from 30mm to 31mm (2015+ Honda Fit) and add 50# #34857inductionfasterB-Spec Honda Fit MT 2015-19 restrictor increases 30mm to 31mm, weight rises 2525 to 2550 lbs.
B-Spec Wheel Offset and Spacer Revision #35466tyres & wheelsfasterB-Spec and C-Spec now permit wheels of any offset if tire doesn't protrude beyond fender; spacers allowed with differing left-right offsets per axle.
B-Spec Set Expiration Date for Unused Spec Lines #35742wordingneutralB-Spec Mini Cooper Countryman R60, Paceman R61, and Nissan Versa 1797cc spec lines expire 1/1/2025 unless appealed by 12/1/2024.
B-Spec BOP Adjustment for Yaris iA, 2020+ Versa, and 07-08 Honda Fit #35382weight -125 lbsfasterB-Spec Honda Fit 07-08 loses 125 lbs to 2400; Versa S 2020+ loses 150 lbs to 2550; Yaris iA 16-20 loses 250 lbs to 2450.
B-Spec 07-08 Honda Fit Rear Sway Bar part # #35473wordingneutralB-Spec Honda Fit 07-08 rear sway bar part number changed to Progress #62.1060.
GT2 Classify Corvette C8 (2020- ) into GT2/ST #33759cars addedneutralChevrolet Corvette C8 (2020–) classified into GT2-ST with 6162cc displacement, 3300 lbs minimum weight, 71mm restrictor.
GT2 Requesting classification for a 2015 Mitjet ST in GT2 #35408cars addedneutral2015 Mitjet ST added to GT2, must run per VTS specifications with complete FIA form CdM008.
STU Letter #35397 addendum #35453wordingneutralSTU Mini Cooper S SC: alternate LEAP OMICRON hood scoop LEP-OMICRON3 permitted.
STU S54 Drysump #35464wordingneutralSTU BMW S54 B32 OEM now permits dry sump oiling system.
B-Spec Eliminate Redundant Trans Cooler Rule #35353wordingneutralB-Spec and C-Spec eliminate case-by-case auxiliary transmission cooler approval requirement.
B-Spec Fix Sonic Hatchback MT Spec Line #35371wordingneutralB-Spec Chevrolet Sonic 5dr Hatch MT allows aluminum radiator #ZZP-ZZ013.
B-Spec Split Spec Line of Automatic and Manual 2nd Gen (09-14) Fit #35251wordingneutralB-Spec Honda Fit MT (09-14) and AT now split into separate spec lines with distinct allowances.
B-Spec Equalize Mazda 2 Headers and clean up spec line #35259weightslowerB-Spec Mazda 2 10-14 weight increases 70 lbs to 2350, cat-delete headers now permitted.
B-Spec Rear Sway Bar Request for Nissan Versa and Versa Note 2013- #35323suspension & brakesneutralB-Spec Nissan Versa and Versa Note 2013-2019 now permit Hardrace HR-Q0146 19mm rear sway bar.
GT2 Rear Blade Spoiler Clarification #35261aerofasterGT1, GT2, GT3, GTL, GTX rear spoiler maximum surface area limit of 295.0 square inches removed.
GT2 GT Direct Injection allowance and rules #35437enginefasterGT1/GT2/GT3/GTL/GTX Direct Injection now permitted if OE, using only OE pump, hoses, injectors.
GT2 REDUCE C6 CORVETTE WEIGHT WITH OEM 7 LITER ENGINE REDUCE BY 150LB #35385weight -150 lbsfasterGT2 Chevrolet Corvette 7011 OEM 7 liter weight reduced 150 lbs, to 3125 lbs.
GT2 GT2/3 remove Direction Injection not allowed in Spec line notes #35439inductionfasterGT2/3 Nissan, Mazda, Mitsubishi 4G93, QR25DE/DD, QE25DE/DD Direct Injection now permitted per 9.1.2.F.7.5.E.
STU ST Electric-Assisted Steering Systems #35066wordingneutralSTL and STU power steering rules clarified to permit electric-assisted and hydraulic-assisted steering systems.
B-Spec B-Spec Hankook Tire for Regionals #35055tyres & wheelsneutralB-Spec allows Hankook tires at regionals only through 6-30-2024; Goodyear only from 7-1-2024 for all events.
B-Spec Clarifying the ECU and Data Acquisition language #35236wordingneutralB-Spec and C-Spec ECU and data acquisition rules clarified: ECU must be unaltered OE, no device capable of altering ECU characteristics permitted; data acquisition expanded to allow tachometer, air-fuel ratio, cylinder head temperature sen…
GT2 Dodge Viper Gen 3 hybrid Kit Update Request #35200inductionslowerGT2-ST Dodge Viper hybrid kit restrictor reduced from 50mm to 45mm flat plates.
P2 E&O - Clarify B.1 modified engine range in AMAC spec lines #35225wordingneutralP2 AMAC modified engine range clarified to 2008 and older stock engines only, restrictor 38mm, weight 1025 lbs.
P2 Replacement Engine Crankcase for 07/08 Suzuki GSX-R1000 Engines #35340engineunclearP2 Suzuki GSX-R1000 07/08 engine crankcase may swap to GSX-S1000 16/19 part #11301-04840.
B-Spec Mazda 3i 2010-2013 5-Speed Manual Gear Ratios #34820wordingunclearC-Spec Mazda 3i 10-13 third gear ratio corrected from 3.84 to 1.84.
B-Spec Error Correction #34955wordingneutralC-Spec Dodge Dart 14-16 bore x stroke corrected to 88.0 x 82.0 mm, displacement to 1998 cc.
GT2 Errors in GTCS Headings and Use of the Terms Category and ClassChange existing GTL and GTA Rules #34453wordingneutralGTL spec lines moved to contiguous position with GT2 and GT3; GTA category and spec lines renumbered and moved behind GTL.
P2 Correct Table 1 for Engine Date Range Specifications #35182wordingneutralP2 Table 1 corrects engine date ranges and brand specifications for Stock and Modified engines across multiple car models.
B-Spec B-Spec Tire #35034tyres & wheelsneutralB-Spec adds Goodyear Eagle RS dry and wet tires as options alongside Hankook; Hankook restricted to regional events from 2024.
GT2 Late E & O #34966weightfasterGT2-ST Dodge Viper including Comp Coupe, ACR/ACR-X with VRL front fascia loses 100 lbs.
B-Spec Initial car classifications and spec lines #34461cars addedneutralC-Spec adds Chevrolet Cruze, Ford Focus, Honda Civic, Mazda 3i, Toyota Corolla, VW Jetta; updates Dodge Dart, Mazda3s, Toyota Corolla specs.
GT2 GT2 Mazda 20B 3 rotor ENO #34765weight -220 lbsfasterGT2 Mazda 20B 3 rotor loses 220 lbs, to 2280, consolidating two spec lines.
B-Spec Hyundai Accent Restrictor Plate #34331inductionfasterB-Spec Hyundai Accent GS Hatchback restrictor plate increases from 39mm to 41mm.
B-Spec Hyundai Accent 2012 Model #34332wordingneutralB-Spec Hyundai Accent GS Hatchback model years corrected from 13–19 to 12–19.
GT2 appendix letter #33635 #34206wordingneutralGT2 BMW engines: 3.4L 6-cyl at 2575 lbs, 4.0L V8 at 2900 lbs, 4.5L V8 at 2950 lbs, 5.0L V8 at 3000 lbs; S54 with 97mm stroke permitted at 2800 lbs.
GT2 Remove Weight and Restrictor Penalty for Corvette C7 Body #34342inductionfasterGT2 Corvette C7 restrictor increases from 73mm to 77mm flat plate, removing weight penalty.
STU 2022 Toyota GR Cup for STU #34449cars addedneutralToyota GR Cup and GR86 Cup (2022-) newly classified in STU at 2700 lbs with 2387 cc engine.
B-Spec Allow ZZP Sonic Aluminum Radiator 1.68 #33660otherfasterB-Spec and C-Spec Chevrolet Sonic allows ZZP aluminum radiator #ZZP-ZZ013; Hatch MT restrictor increases to 34mm.
B-Spec Fasteners for Bumper Caps #33797wordingneutralB-Spec and C-Spec bumper caps now allow positive fasteners like machine screws and T-nuts or rivet-nuts; self-drilling and sheet metal screws prohibited.
B-Spec Allow CAN Bus Connection to Data Systems #33806wordingneutralB-Spec and C-Spec allow CAN bus connections to data systems for monitoring only; systems must not send data.
B-Spec Request Ford Fiesta weight reduction 25lbs #33890weight -25 lbsfasterB-Spec Ford Fiesta 5dr and 4dr lose 25 lbs each, to 2470 lbs minimum weight.
B-Spec BoB Adjustments #34208weight -25 lbsunclearB-Spec Ford Fiesta 5dr and 4dr lose 25 lbs each to 2470; Honda Fit MT and CVT lose 50 lbs each to 2525; Mazda2 loses 50 lbs to 2280; Kia Rio restrictor increases from 39 to 41 mm; Mini Cooper variants gain 75 lbs to 2675 with larger restri…
B-Spec T5 Ride Height Rules. #33552suspension & brakesneutralB-Spec minimum ride height set to 6 inches, C-Spec to 5½ inches.
B-Spec T5 Spring Allowance #33557suspension & brakesneutralB-Spec springs capped at 500# front and rear; C-Spec at 600# front, 800# rear; both may be strapped to body.
B-Spec T5 Wheel Minimum Weight #33558tyres & wheelsneutralB-Spec wheels minimum weight set to 13 lbs, C-Spec to 17 lbs.
B-Spec Threaded Metal Inserts for Plastic Intake Manifolds #34164wordingneutralB-Spec and C-Spec allow metal threaded inserts in plastic intake manifolds for throttle body fasteners.
B-Spec T5 Rules Feedback #33595wordingneutralB-Spec and C-Spec wording clarified: CATEGORY to CATEGORIES, rules priority clarified for tire sizes, rim widths, springs, anti-roll bars, performance equipment.
GT2 Request to class 2011 Porsche Cayman S #33771cars addedneutral2009-2012 Porsche Cayman S classified in GT2, 3.4L, RWD, no PDK transmission allowed.
GT2 Please classify Fields Cardinal V8 #33784cars addedneutralFields Cardinal V8 classified in GT1 with Ford V8 engine, 4.9L displacement, 2100 lbs minimum weight.
P2 Clarify minimum side body height requirement #34143wordingneutralP2 side body height requirement clarified: outermost surface between wheel openings must equal front axle centerline height.
P2 Clarify closed cockpit single seat car allowance #34144wordingneutralP2 closed cockpit single seat cars now prohibited unless specifically allowed in Table 1.
GT2 Adding Ginetta G56 GTA Factory ProTune for GT2 Class #33825wordingunclearGT2 Ginetta G56 GTA may now use Factory installed ProMap ECU Map.
P2 Remove redundant effective date language and update engine table #34012wordingneutralP2 engine table wording updated; redundant effective date language removed.
P2 E&O - Correct dimensional equivalents #34038engineslowerP2 motorcycle engines: 2011+ Kawasaki restrictor reduced to 34mm, minimum weight raised to 1100 lbs; 2009+ other brands weight raised to 1100 lbs.
STU Alternate OEM Miata Intake Manifold #33827wordingneutralSTU Mazda BP5A classified at 1839 cc maximum displacement, 2023-04-01.
B-Spec Early Model Mini #33363inductionfasterB-Spec Mini Cooper R56 MT/AT and Clubman R55 fuel pressure regulator increased from 40mm to 41mm with OE catalyst.
B-Spec Helper Versus Tender springs. #33866suspension & brakesslowerB-Spec may use helper springs up to 500 pounds rate; tender springs now prohibited.
STU E&O STU NA Weight Chart. #33737weightfasterSTU minimum weight chart updated: 2450cc to 2595lbs, 2600cc to 2710lbs.
B-Spec Split up Spec lines for Automatic/Manual 2nd Gen Fit #33292enginefasterB-Spec Honda Fit 09-14 Automatic now allows aftermarket exhaust/header; Manual unchanged.
GT2 GT2 Mazda 13B Turbo #33729engineunclearGT2 Mazda 13B Street Port turbo changes from EFR 76/70 to BW7670 or Garrett G30-660 with 46mm TIR at 2280 lbs.
B-Spec Request to Split Spec Lines for Automatic Models #33270wordingneutralB-Spec Chevrolet Sonic and Honda Fit and Mini Cooper split into separate manual and automatic spec lines with distinct transmission ratios and final drives.
B-Spec Tire Rule Request #33350tyres & wheelsneutralB-Spec tire rule adds Hankook 200/580R15 Z217 as alternative to 205/50R15 C51; no mixing wet and dry.
GT2 Request Permission to Use a Substitute Turbo #33337inductionfasterGT2 Porsche SOHC 2478/2681/2992 turbo sizes increase from 42mm to 44mm SIR to TIR.
GT2 Request to Reduce Restriction on C7 GT2 Corvette #33342inductionfasterGT2-ST Chevrolet Corvette 14-19 L76 5967 restrictor increases from 70 to 73 mm.
GT2 Toyota 4A-F and 4A-FE 1.6L DOHC 16V Engine Request #33415cars addedneutralGT2 Toyota 4A-F and 4A-FE 1.6L DOHC 16V engines newly classified in spec line.
GT2 GT2 Mazda 13b turbocharger part # update #33437enginefasterGT2 Mazda 13B Street/Bridge Port turbocharger changes from EFR 70/76 to 76/70, compressor from 42mm to 46mm.
GT2 GT2-ST BMW E36/46 spec line remove #33610wordingneutralGT2-ST BMW E36/46 spec line adds MA Shaw carbon/composite door offerings to Notes.
GT2 GT3 Choke option effective 1-01-2023 #33669inductionneutralGT3 normally aspirated cars may use intake chokes instead of SIRs, fitted to each carburetor barrel, same size as required SIR.
GT2 GT3 2.0L choke/weight option #33670inductionfasterGT3 2.0L 4-valve non-turbo engines may run unrestricted at 2060 lbs instead of with a choke restriction.
P2 Request to Classify Sebeco NP01 #33378cars addedneutralSebeco NP01-EVO and Elan NP01 Mazda 2.0L MZR added to P2, 1600 lb minimum, no restrictor required.
P2 Radical spec line clarifications #33485wordingneutralP2 Radical SR3/SR4/Cup/Club Sport/Pro-Sport/PR6 removes assisted shifting requirement across all spec lines.
P2 E&O original class intent #33519wordingneutralP2 chassis rules clarified to allow composite materials in non-fully-composite construction; anti-intrusion panel attachment standardized; Stohr and converted F600 cars added with specific allowances.
P2 Update Engine Table Spec Line B.1 #33608engineunclearUnable to summarize: the change to P2 Engine Table Spec Line B.1 is not detailed in the provided text.
GT2 GT2 (TA2)/GTA Part Number Update #33315wordingneutralGT2 TA2 and GTA throttle body part numbers updated to GM 90mm electronic #12570790 or Edelbrock 90mm mechanical #33869 or #3870.
GT2 Ginetta G56 GTA - Optional Wheels #33357tyres & wheelsneutralGT2 Ginetta G56 GTA gains optional 18" x 9" and 18" x 10" wheels.
GT2 Allow the MAShaw Body Kit on the GT2/ST Spec Line for BMW E36/E46 #32447aerofasterGT2/ST BMW E36/E46 now allows MAShaw body kit parts: wide body, bumpers, fenders, rockers, flairs.
B-Spec Utilize the Data - Make BoP Changes #32179weight -225 lbsfasterB-Spec Honda Fit 15-19 weight drops 225 lbs to 2575 lbs.
GT2 Request for C5/C6 Corvette Restrictor Size Review #32982inductionfasterGT2 Chevrolet Corvette L76 5967 restrictor increases from 73mm to 74mm.
GT2 Tail lights on all GT category race cars. #32799wordingneutralGT taillights may now be original style or a panel graphic with functioning red LED brake lamps; wording change only.
GT2 Addendum to letter #32514 Ginetta GTA G56 #33076cars addedneutralGinetta GTA G56 added to GT2 as spec car: 2600 lbs, 3.7L Ford V6 sealed, 6-speed Quaife sequential.
B-Spec Request new Mazda Rear Swaybar #32769wordingneutralB-Spec Mazda2 10-14 rear sway bar now allows part 0000-04-2203-RR or 0000-04-2312.
GT2 Information requested for carbon roofs on BMW E36/E46 cars in GT2 #32682wordingneutralGT2 BMW E36/E46 carbon roof and door suppliers added to notes: Lang Racing, 2M Automotive, Flossmann, MA Shaw.
GT2 Request to Allow the 95mm S54 BMW Crankshaft in GT2-ST #32698weightslowerGT2-ST BMW E46 M3, E36, Z3, 5000cc V8 can use 95mm S54 crankshaft at +150 lbs.
GT2 Request to classify Audi R8 FIA GT4 to GT2 #32805cars addedneutralAudi R8 GT4 classified to GT2 with 5.2L displacement, 3000 lbs minimum weight, per factory specs restrictor.
STU Request Mazda 13 B turbo #32668cars addedneutralSTU Mazda 13B Turbo classified, streetport only, stock turbos prohibited, alternatives allowed.
STU Hood Vents and Intercooler Scoops #32733aerofasterSTU OEM louver vents now exempt from vent count and 200 square inch allowance.
STU Non 4 valve weight reduction removed #32808enginefasterSTU 2400cc non-4-valve engines gain 9% base weight reduction; DI turbo prep limits removed.
STU Error in new minimum weight table when combined with other text #32711engineslowerSTU normally-aspirated 2976–3200 cc single-throttle engines lose 10% base engine weight reduction.
STU Redundant Language in May GCR #32713wordingneutralST redundant language removed from balance shaft and pulley modification rules.
B-Spec Request to Remove Part Numbers from Kia/Hyundai Spec Lines #32378inductionslowerB-Spec Hyundai Accent GS and Kia Rio restrictor increased from 36mm to 39mm flat plate.
GT2 Typo in rules for shocks #32308wordingneutralGT2 shock absorber attachment points clarified as moveable; wording correction only.
GT2 additional response to letters #31898 & 32083 #32424weight +140 lbsslowerGT2 Porsche 104.0 x 88.0 engine weight increases from 1950 to 2090 lbs; 2V variants may use Borg Warner EFR 76/70 42mm turbo.
P2 E&O Clarification of Chassis Construction Requirements #32469wordingneutralP2 chassis construction rules clarified: fully composite or partially composite requiring composite for mobility allowed; partial composite must roll without composite parts.
P2 Clean up P2 wording #32525wordingneutralP2 classification wording cleaned up in GCR section 9.1.8.C and Contents.
STU Opposed to the Proposed STU Weight Chart #32381wordingneutralSTU cars that qualified for 9 inch wheels in 2021 may continue through 2022 only.
STU Clarification request for GCR 9.1.4.D.3.a Splitter Definition #32414wordingneutralSTU splitter definition clarified: must be single-plane with no vertical deviations, attached to lowest front point.
P2 After Market to Aftermarket #32373wordingneutralP2 Oldsmobile cam rules clarify aftermarket manufacturer requirements; wording only.
STU Request Adjustment to Min Weight for STU BMW E36 M3 (95-99) #31535weight -90 lbsfasterSTU BMW S52B32 minimum weight drops 90 lbs to 3110; max displacement cut to 3152 cc.
STU BMW E36 M3 Canadian (North American) S50B32 engine #31866cars addedneutralSTU BMW S50B32 Euro classified at 3201 cc displacement, 3300 lbs minimum weight.
STU Engine Swap Origin Country #32209wordingneutralST engine swap origin country requirement changes from North America to the United States for case-by-case approval.
STU CRX/Civic Del Sol #32214weightslowerSTU Honda CRX (84-91) and Civic Del Sol (93-97) ineligible for front wheel drive weight reductions.
STU Error correction #32383tyres & wheelsfasterSTU vehicles at or over 2950 lbs base weight may use 9 inch wide wheels instead of 8.0 inch maximum.
STU Single TB Weight Modifiers Add to Chart #32393weightfasterSTU minimum weights reduced: 2450cc to 2596 lbs, 2500cc to 2635 lbs, 2550cc to 2675 lbs.
B-Spec Request spring attachment #31351suspension & brakesneutralB-Spec allows springs strapped to body for rebound control; removes requirement for OEM or kit bump stops.
B-Spec Limit Rear Camber to 1.75 Degrees Section 9.1.10.E.35 #31393suspension & brakesslowerB-Spec strut tower modifications permitted for camber adjustment only, limited to 1.75 degrees.
B-Spec Letter 31442 Part# Correction #32060wordingneutralB-Spec Mazda2 10-14 undertray part numbers corrected to DO8C-56-110A, DO8C-56-311, DO7A-56-321.
GT2 Request to Classify Ginetta G40 in GT2 #31597cars addedneutralGinetta G40 classified in GT2 with Mazda MZR/L5-VE engine, 2488cc or 2399cc, 1950 lbs base weight.
GT2 2021 Supra GR GT4 #31737cars addedneutralToyota Supra GT4 added to GT2-ST: 3000cc, 3000 lbs minimum, factory restrictor.
GT2 Proposed Technical Bulletin #31900wordingunclearGT2 Porsche 944/924 may use ERC 76/70 Turbo instead of Jayco super 50.
P2 Add spec line for Beasley B2 #32147cars addedneutralP2 adds Beasley B2 spec line with 1350 lbs, Mazda 12A, 40.5mm venturi, 16.5in wing.
P2 E&O Table 1 spec line wing terminology #32148wordingneutralP2 wing specs correct terminology from 'cord' to 'chord' for 16.5in single or dual element wings.
P2 E&O class name #32196wordingneutralP2 Converted F5 cars reclassified as Converted F500 cars; suspension must comply with F500 requirements, minimum width 55 inches.
STU Single TB Weight Modifiers #31449weightfasterSTU normally aspirated engines: minimum weights reduced up to 310 lbs; single throttle body weight reduction removed.
STU Request to Remove A4 1.8t from STU Spec Line Tables #31465weightslowerSTU Audi A4 1.8T minimum weight fixed at 3050 lbs, VF30 turbo with 35mm restrictor now required only.
STU Improved Touring Tires #32063tyres & wheelsneutralSTL and STU Improved Touring vehicles must conform to 9.1.4 Tires & Wheels requirements.
B-Spec Request to Classify 2020-21 Versa S #30759cars addedneutralB-Spec Nissan Versa S 2020- classified at 2700 lbs with 38mm restrictor, 1598cc engine.
B-Spec Request to Classify the Toyota IA sedan & Scion IA Sedan for 2022 #31045cars addedneutralToyota/Scion IA Sedan (2016-2020) classified for B-Spec at 2700 lbs with 38mm FPR.
GT2 GT2/ST Porsche Cayman #31451 correct TBR size error #31991enginefasterGT2 Porsche Cayman 05-15 turbo restrictor increases from 70mm to 75mm.
P2 E&O Engine section #31969enginefasterP2 motorcycle engines increase to 1505cc max, two-stroke to 1205cc max; automotive engines gain 50 lbs minimum weight to 1350.
STU Request Allowance for Balance Shaft Delete in STU #31434enginefasterSTU engines may delete balance shafts and plug openings; alternate pulleys allowed for timing belt or chain operation only.
STU Request Louvers in hood vents #31916aeroneutralSTU hood vents allowed to include louvers within 200 sq. inch area.
B-Spec Request to add 2007-2008 Honda Fit #30853cars addedneutral2007-2008 Honda Fit automatic added to B-Spec at 2525 lbs with 1499 cc engine.
GT2 Restrictor Clarification for 2015 Cayman #31451wordingunclearGT2 Porsche Cayman 05-15 uses Throttle Body Restrictor instead of Flat Plate Restrictor at 2700 lbs.
P2 E&O letter #31539 – Control Area definition #31783aeroslowerP2 Control Area definition narrowed; aerodynamic attachments and vertical structures like turning vanes now prohibited.
STU Request to Add Honda K23 Spec Line #30682cars addedneutralSTU adds Honda K23 with 2354cc displacement and minimum weight per chart, K24 block allowed with K23 internals and head.
STU RE: Aug FT letter 30682 #31060enginefasterSTU Honda K23 internals rule relaxed to require only K23 crankshaft, allowing other internal modifications.
STU Throttling Device Clarification #31323wordingneutralSTL and STU piston engines clarified: intake manifold and cylinder head porting remains free.
P2 BoP adjustment effective 1-1-22 #31538wordingunclearP2 Engine Table Spec Line B.1 changed effective 1-1-22, details not provided in excerpt.
P2 E&O clarification of "Control Area" definition #31539wordingneutralP2 Control Area definition clarified: floor extensions and aerodynamic attachments on bottom or top side now explicitly included.
B-Spec Rules Clarification of Body and Camber Plates #30814suspension & brakesneutralB-Spec upper strut slotted plates no longer require manufacturer's original bolt holes or serve as reinforcement.
GT2 Turbo Request for 13B Engine #30656engineunclearGT2 Mazda 13B street port adds EFR 70/76 turbo with 42mm restrictor at 2280 lbs.
GT2 Request car classification #31032cars addedneutralGT3 Fun Cup Beetle EVO3 classified with 1984 cc sealed SOHC engine, 2060 lbs minimum weight.
B-Spec Rules Clarification of Body and Camber Plates #30814suspension & brakesfasterB-Spec upper strut slotted plates no longer must use manufacturer's original bolt holes.
GT2 Correct letter 30565 GT2/ST #31088weightfasterGT2 Dodge Viper Comp Coupe ACR/ACR-X loses 100 lbs minimum weight to 3275.
P2 P2 CN Engine Rebuild Clarification #31000wordingneutralP2 CN Honda K20A-FD2 engine rebuild rules clarified: machining prohibition replaced with specific restrictions on balancing, porting, polishing, valve jobs, cylinder honing.
GT2 Request the 04-06 Pontiac GTO WC Car Be Added to the GT2/ST Chart #30339cars addedneutral04-06 World Challenge Pontiac GTO added to GT2-ST: 6062 cc, 3000 lbs minimum, unrestricted.
GT2 Request to Update GTA Obsolete Part Numbers #30615wordingneutralGTA part numbers updated: 0-80541-1 to 0-80541-2 in two sections and 6010 to 6014X in TA2 Appendix.
GT2 GTX class correction to GT2/ST #30973cars addedneutralGrullon GT with 2.0L K20 moved from GTX to GT2-ST, minimum weight 2350 lbs, unrestricted.
P2 F5 P2 Conversion #30856aerofasterConverted F5 cars in P2 minimum width reduced to 55 inches from F5 spec.
P2 Clarify minimum body width requirement #30859wordingneutralP2 clarifies minimum body width requirement between front and rear wheels for Ralt RT40, RT41, Swift 008, 014.
GT2 Porsche Cayman Engine Modification and Engine Request #30472inductionfasterGT2-ST Porsche Cayman restrictor increases from 65mm to 75mm flat plate at 2700 lbs.
GT2 Request weight clarification Viper CC #30565weightfasterGT2 Dodge Viper including Comp Coupe, ACR/ACR-X minimum weight reduced 100 lbs to 3275 in VRL Spec.
GT2 Variance, 2021 TA2 Rules vs GCR Appendix L #30641wordingneutralTA2 minimum weight set to 2930 lbs with free tire make and size.
STU STU Fender flares #30696wordingneutralSTU fender flare wording clarified: exterior contour of any wheel opening may not change opening size, location or shape from side view.
STU Request weight reduction for 12A bridgeport motor in Miata #30751weight -200 lbsfasterSTU Mazda 12A Bridge Port Miata weight reduced from 2550 lbs to 2350 lbs.
B-Spec Transmission Cooler Requests #30079wordingneutralB-Spec Honda Fit and Mini Cooper models gain alternate transmission ratios and final drives to allow Setrab 50-119-7612 cooler.
B-Spec Request to classify the 07 Honda Fit #30083cars addedneutralB-Spec Honda Fit 2007-08 classified with 1499cc displacement, 2450mm wheelbase, 2525 lbs minimum weight.
B-Spec Request Ford Fiesta Eibach Rear Sway Bar Part Number 35143.320 #30340otherneutralB-Spec Ford Fiesta 5dr Hatchback allowed Eibach rear sway bar #35143.312 or #35143.320.
B-Spec Restrictor rule #30474inductionfasterB-Spec restrictor range changes from 0.060" ±0.005" to 0.050"-0.079".
B-Spec Rear wipers on all cars #30585weightfasterB-Spec rear window wipers and wiper motor removal now allowed.
P2 E&O tonneau cover provision in cockpit opening section #30459wordingneutralP2 tonneau covers now allowed to meet minimum dimensions; equipment attachment requirements clarified.
P2 Remove effective dates in Table 1 #30468wordingneutralP2 multiple chassis models remove effective dates from Table 1 specifications.
P2 E&O Maximum Valves Per Cylinder #30560engineneutralP2 engines limited to 4 valves per cylinder maximum across all three spec lines.
STU Request for Fender Flare Clarification #30375wordingneutralSTU fender flare rules clarified: maximum 2 inches, must cover tire contact patch from above, cannot alter body configuration or wheel opening geometry.
B-Spec Allow 4 lug hub conversion to R60 and R61 MINI #29863wordingneutralB-Spec Mini R60 and R61 allow 4-lug hub conversion with specified bearings and brake rotors.
B-Spec Honda Fit Years on Spec Line #30078wordingneutralB-Spec Honda Fit model years expand from 09-12 to 09-14.
B-Spec Hyundai/Kia restrictor size incorrect #30380inductionslowerB-Spec Hyundai Accent GS and Kia Rio restrictor reduced from 40mm to 36mm flat plate.
B-Spec Clarify tire compound in rules #30387tyres & wheelsneutralB-Spec must use Hankook P205/50ZR15 Z214 C51 or Z217 rain tyres for SCCA Majors, Super Tour, Runoffs.
GT2 GT2 tiger firing order #30421wordingneutralGT2 Sunbeam SBF 302 engine firing order option now explicitly allows Boss 302 variant.
STU Provision for Interchangeable Engine Components Already Allowed #30342engineunclearSTU Honda S2000 allows F20/F22 K24 crankshaft with chart weight for achieved displacement.
STU ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wordingneutralST oil coolers and filters now explicitly allowed to be added or substituted; wording clarifies existing permissions.
B-Spec Spec Tire Recommendation #29480tyres & wheelsneutralB-Spec tire rules clarified: Hankook Z214 dry and Z217 rain required at Majors/Super Tour/Runoffs after 6-1-2021; regional racing allows any DOT race tire through 2021.
B-Spec Make restrictor thickness unique for B Spec #30349wordingunclearB-Spec restrictor thickness set to 0.060 inches plus or minus 0.005 inches.
GT2 GT2-ST CORVETTE CHANGES #30029weight +100 lbsslowerGT2-ST Corvette (-2019) LS2 and L76 5967cc gain 100 lbs minimum weight to 3100; 6162cc variants gain 50–100 lbs; 7011 gains 100–50 lbs; L76 restrictor opens 70 to 73 mm.
GT2 29742 Change new wording to read as: #30329wordingneutralGT2 Ford Mustang/Thunderbird Boss 302 firing order now optional from later SBF 302 versions.
P2 Add a new spec line for a 2-cycle, 3-cylinder engine up to 820cc #30272cars addedneutralP2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front and 14-15 rear wheel width.
STU Super Touring Alternate Miata Hubs #30345wordingneutralSTL/STU 90-05 Mazda Miata gains approval for Mazda Motorsports Development alternate front wheel hubs.
B-Spec Request to Classify Hyundai Accent (RB) 2012-2019 #29484cars addedneutralB-Spec Hyundai Accent GS Hatchback 2013-2019 classified at 2525 lbs with 40mm flat plate restrictor.
B-Spec Countryman production years incorrect #29864wordingneutralB-Spec Mini Cooper Countryman R60 and Paceman R61 production years corrected from 11-13 to 11-16.
B-Spec Toyota Yaris Model Year Corrections #29896wordingneutralB-Spec Toyota Yaris Hatch model year spans corrected from 07-12 to 07-11 and 12-18 added.
B-Spec Correction spec lines for ride height Mini Cooper all models #29952wordingneutralB-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 & brakesneutralB-Spec allows removal or material modification of metal or plastic brake dust shields.
B-Spec Request to allow OBX header and restrictor to R55 Clubman 08-10 #30024engineunclearB-Spec Mini Cooper Clubman R55 11-15 permitted OBX header with 40mm flat plate restrictor.
GT2 ABS Restrictions #30064wordingneutralGT2 ABS braking systems now allowed if shown on individual Spec Line.
STU Brake Component Relocation #29990wordingneutralST cars may relocate ABS actuation hardware and wiring anywhere in engine compartment.
STU Porsche PDK #30081wordingneutralSTU Porsche PDK automatic transmission limited to 8 forward speeds instead of torque converter restriction.
STU Reference Letter #29333 Proposed STU 13B Spec Line Changes #30086inductionfasterSTU Mazda 13B Street Port 2400 removes choke location restriction, allows auto-type 2bbl with dual-Y manifold.
STU Drive Shaft Request #30087wordingneutralSTU driveshaft and half-shaft materials change from OEM-type to steel or aluminum.
GT2 Request change to engine firing order rule #29742engineunclearGT2 Ford Mustang/Thunderbird Boss 302 firing order becomes unrestricted.
GT2 Request E-46 BMW M3 balance of performance #29833weight -100 lbsfasterGT2 BMW E46 M3 weight reduced from 2600 to 2500 lbs.
STU 13B Rules Adjustment #29333cars addedslowerSTU Mazda 13B Street Port classified at 2400 lbs minimum weight, replacing peripheral and bridge port variants.
B-Spec Request clarification of B14 shock package for any and all cars #29483suspension & brakesneutralB-Spec: Bilstein B14 suspension kits removed from all car spec lines; clarified B14 shock or strut use requires CRB approval of mounting adaptors.
B-Spec Cleanup of spec lines #29495removedneutralB-Spec removes Chevrolet Sonic 12-19, clarifies Toyota Yaris Hatch 07-12 and Sedan 07-12.
GT2 Request for Bigger Engine in Plymouth Breeze #29380cars addedneutralGT2 Chrysler/Dodge/Plymouth 2429cc DOHC engine classified at 1950 lbs, unrestricted fuel induction.
P2 Balance of Performance adjustments effective 01-01-2021 #29822inductionfasterP2 Honda K20A-FD2 intake restrictor reduced from 55mm to 50mm, making cars faster.
STU Request clarification on wing measurement #29640aeroneutralST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch.
GT2 rescind GT2 stock car bodies removal #29219cars addedfasterGT2 stock car bodies removal rescinded; 1997-current year commercially available stock car bodies remain allowed.
GT2 E&O Typos in Appendix L #29447wordingneutralGT2 Appendix L renumbering eliminates sections .17 through .19 after 4.8.4.2.10.3.6.
GT2 GT2 wing width wording correction #29469wordingneutralGT2 TA2 wing width maximum set to 65 -5/16 inches, previously undefined.
B-Spec Allowance Versus Requirement for R56 Mini Cooper #29127suspension & brakesfasterB-Spec Mini Cooper R56 40mm flat plate restrictor requirement removed, suspension and header parts now allowed.
GT2 GT Category Wording #29193wordingunclearGT1, GT2, GT3, GTL, GTX now permit turbocharging/supercharging if listed on spec line.
GT2 Corvette GT2-ST intake manifold #29221wordingneutralGT2 Chevrolet Corvette -2019 LS1/LS6 allows DORMAN part # 615-900 alternate intake manifold.
GT2 997.2 E&O link to 27915 #29373weightfasterGT2 Porsche 997.2 GT3 Cup minimum weight drops to 2900 lbs.
P2 E&O clarification of P2 rear wing requirements #29205aeroneutralP2 rear wing requirements clarified: standard wing 6×12 inches, end plates 14-inch square; alternate 110cm width wing 9×18 inches, end plates 14×18 inches.
STU Request for Advanced Aero Rule Wording Clarification. #29124wordingneutralSTU fender flare rules reworded: up to 2" per corner allowed with 1% weight penalty total.
GT2 Request for allowance Trans Am SGT #28951wordingneutralGT2 BMW E46 M3, E36, Z3, and 5000cc V8 gain Trans Am SGT spec allowance: regular shifter 3000 lbs., paddle shifter plus 150 lbs.
GT2 Omitted GT2 fender/hood openings #29171aeroneutralGT2 allows up to four hood/fender louvered panels, max 600 sq inches total, min five slots each, mounted in front of windscreen.
STU Minimum Weight Determination #27695wordingneutralSTL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis adjustments.
STU ST Gurney flap Wicker clarification #29012wordingneutralSTL and STU rear wing rules clarify that wicker is a Gurney flap; no performance change.
GT2 TA2 Gurney flap wicker clarification #28874wordingneutralTA2 Gurney flap wording clarified: terminology standardized to 'Gurney flap', height limits and thickness specifications remain 0.50 inch / 0.625 inch or 0.375 inch / 0.0625 inch depending on configuration.
GT2 STO Gurney flap wicker clarification #28883wordingneutralSTO rear wing wording clarified: 'wicker' changed to 'Gurney flap' in maximum chord and mounting height rules.
STU Request for Alternate Intake Manifold #26514wordingneutralSTU request for alternate intake manifold denied; no rule change issued.
STU Request for Addition to GT3 Approved Turbo List #27576wordingneutralGT3 and STU add Borg-Warner EFR6258 to approved turbocharger list.
STU Request BoP for my Car #29004wordingneutralSTU large displacement turbo engines limited by GCR turbo list; non-turbo trim suggested as more competitive.
STU Sequential Shifters in STU #29031wordingneutralSTU sequential shifters referred to Board of Directors for approval; no change implemented yet.
B-Spec Request to change units on wheelbase for consistency with wording #28786wordingneutralB-Spec wheelbase measurements converted from inches to millimeters for consistency across all cars.
GT2 Request to Adjust Weight of OEM 8.4 Viper #28739weight -50 lbsfasterGT2 Dodge Viper 8400 OEM minimum weight drops 50 lbs to 3275.
GT2 Request to Adjust Weight of OEM Chevrolet Corvette #28896weight -50 lbsfasterGT2 Chevrolet Corvette -2019 OEM minimum weight cut 50 lbs to 3275.
P2 Classify Elan NP01 in P2 Table 1 #28812cars addedneutralElan NP01 classified in P2 Table 1 as Spec Line car with 2000cc displacement and P2 Engine Table restrictor.
STU Rotary Help #27833cars addedneutralSTU Mazda 13B Bridge Port and Street Port engines added with 2550 and 2250 lbs minimum weights respectively.
B-Spec Transmission cooler for automatic equipped cars #28171otherneutralB-Spec Chevrolet Sonic 5dr Hatch and 4dr Sedan allow Setrab transmission cooler for automatic-equipped cars.
B-Spec Spring Update for all models #28384suspension & brakesneutralB-Spec: multiple models allow specific suspension kits and damper assemblies.
B-Spec B-Spec Balance of Performance based on 2018 and 2019 seasons #28394induction -25 lbsslowerB-Spec Ford Fiesta 5dr gets 36mm restrictor, 4dr gets 34mm, Honda Fit 09-12 loses 25 lbs to 2525, Fit 15-20 restrictor reduced 32mm to 30mm, Mini Cooper 07-10 gets 40mm restrictor.
GT2 Request Corvette engine parity #28576weightfasterGT2 Corvette LS6 may reduce weight by 50 lbs.
P2 SCCA Enterprises ESR / P2 engine restrictor testing #28669engineneutralP2 Enterprises Sports Racer adds 55mm flat plate intake restrictor Part # WM303013 as alternative to SIR.
GT2 Request to revisit Panoz GT-S BoP #28280wordingunclearGT2 Panoz GT-S now allowed to use TA2 Choice Engine with any 5-speed H-pattern transmission.
GT2 GT2-ST Corvette LS2 & L76 #28583inductionfasterGT2-ST Corvette LS2 restrictor increases from 70mm to 75mm flat plate.
P2 Add ESR inlet restrictor #27869inductionslowerP2 Enterprise Sports Racer 2.3L engine now requires SIR or Flat Plate restrictor sized in 0.5mm increments.
STU Request to approve Honda S2000 HKS supercharger #27281enginefasterSTU Honda S2000 adds HKS Supercharger kits 12001-AH006 and 12001-AH010 as allowed.
STU Request BoP on the Lotus #27637weight +100 lbsslowerSTU Lotus Elise Cup R and SC models, plus Exige SC, gain 100–200 lbs minimum weight.
STU Turbo Inlet Restrictor On MK5 Volkswagen #27704inductionslowerSTU Volkswagen GTI/GLI MK5 and Jetta Mk4 may install turbo inlet restrictor in OEM turbo inlet housing.
STU Honda K20C1 removal #27732inductionslowerSTU Honda K20C1 Turbo I4 restrictor reduces from 36mm to 35mm.
STU Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0 #27884engineslowerSTU GM Ecotech LNF now allowed with turbo removed or with LE5 head and intake manifold, meeting STL specs.
STU Alternate Engine for Porsche 944 #28259engineunclearSTU Porsche 944 now permits VW/Audi 1.8L and 2.0L turbo engines as alternates.
B-Spec Request for Model Years Updating #27850wordingneutralB-Spec Sonic extended to 2019, Fiat 500 limited to 2015, Fiesta models extended to 2019, Fit expanded to 2015-2019.
B-Spec Request to classify Min Cooper models #27861cars addedneutralB-Spec Mini Cooper R50, R55, R58, R60, R61 models newly classified at 2545–2625 lbs with 40mm restrictor for 12+ models.
B-Spec remove fog lights #27947wordingneutralB-Spec fog lamps must now be removed and holes completely covered, reversing prior allowance.
B-Spec add sonic sedan #27948cars addedneutralB-Spec Chevrolet Sonic 4dr Sedan (12-19) added at 2650 lbs with 32mm flat plate restrictor.
GT2 Request 991.2 Porsche engine displacement verify typo #28194enginefasterGT2 Porsche 991.2 GT3 Cup Car engine displacement increases from 3.8L to 4.0L.
P2 Request for Fly by Wire Rule Wording Change #28247wordingneutralP2 fly-by-wire throttle control wording clarified: stock ECUs with drive-by-wire must activate original throttle shaft mechanism.
STU Please Modify the STU Wheel Size Rule for Clarity #27694weightfasterSTU vehicles over 2951 lbs base weight may use 9 inch wide wheels, up from 2950 lbs.
STU Turbo Engine Cars Base Weight #28032wordingneutralSTU turbocharged engines now use base weight instead of minimum weight, with 3% DI increase applied to base weight.
B-Spec Request for Automatic Transmission Inclusion #27686wordingneutralB-Spec now permits automatic and CVT transmissions on all legal cars meeting spec line.
B-Spec Request to Add Transmission Coolers to Automatics #27687otherneutralB-Spec automatic transmissions may use auxiliary coolers on case-by-case basis with part number approval.
GT2 Windshield Clips #27323wordingneutralGT1, GT2, GT3, GTL, GTX may omit windshield clips if factory glass is bonded per original specifications.
GT2 Request to Add Chevrolet SS Body to Appendix L #27898cars addedneutralGT2 Chevrolet SS replaces Dodge Charger; all stock car bodies removed from GT2 in 2021.
B-Spec Add Yaris Sedan #26797cars addedneutralToyota Yaris Sedan 2007- added to B-Spec at 2400 lbs with 1491cc engine.
B-Spec Add 2011-2016 Fiesta Sedan #26798cars addedneutralB-Spec adds 2011-2016 Ford Fiesta 4dr Sedan, 1596cc, 2495 lbs minimum weight.
B-Spec add 2015-2019 Kia Rio #26799cars addedneutralB-Spec Kia Rio 5-door/LX years expanded to 2012-2019.
B-Spec Error and Omissions #27858suspension & brakesneutralB-Spec Mazda2 (10-14) allows specific suspension, intake, exhaust, and bushing parts; removes air duct Mz26-117-33100.
GT2 Request Factory Five Daytona coupe classification #26308cars addedneutralFactory Five Type 65 Coupe R with Ford 302/351 or 5.0/5.2L NA added to GTX-MISC at 2600 lbs.
GT2 Porsche 991.2 GT3 Cup GT2 Classification #27701cars addedneutral991.2 GT3 Cup Car classified in GT2 at 3100 lbs with 63mm throttle body restrictor.
GT2 Request for Acura NSX Spec Line Changes #27755weightfasterGT2 Acura NSX minimum weight reduced from 3000 to 2700 lbs.
GT2 GT2 991.1 restrictor size change #27914inductionfasterGT2 Porsche 991.1 GT3 Cup restrictor size increases from 67 mm to 70 mm.
GT2 GT2 996/997.1 weight change #27915weight -100 lbsfasterGT2 Porsche 996/997.1 GT3 Cup minimum weight reduced 100 lbs, to 2800.
GT2 GT2/ST Corvette comp adjustment #27920inductionslowerGT2/ST Corvette -2019 5967cc restrictor reduced from 75 mm to 70 mm.
P2 Request for addition of BMW Engine in P2 Engine Table #27821cars addedneutralP2 adds BMW to motorcycle-based engine options in 4-cycle line alongside Kawasaki, Suzuki, Yamaha, Honda.
B-Spec Request for Correction of Production Years for Mini Cooper #27226wordingneutralB-Spec Mini Cooper production years corrected to 2011-13.
STU Request for an electronic throttle body #27342wordingneutralSTU cars with manual OEM throttle bodies may convert to OEM electronic throttle body of same inner diameter.
B-Spec Request for Corrections to 9.1.10 E Item #27 D and E #27224inductionfasterB-Spec Mazda 2, Fiat 500, 2007-10 Mini Cooper permitted to replace primary cat/exhaust manifold with approved header.
B-Spec Remove wording in the B-spec rules #27388wordingneutralB-Spec removes year-specific eligibility and twelve-year competition window wording.
B-Spec Request to add 2013 Honda Fit model year #27491cars addedneutralB-Spec Honda Fit model year expanded to include 2013, now covers 2009–2013.
P2 Update Engine Table Line E notes #27414inductionslowerP2 Honda K20A-FD2 non-composite chassis must use 55mm flat plate intake restrictor at 1500 lbs minimum weight.
P2 Update P2 Engine Table spec lines to reflect 3/1/2019 #27254inductionslowerP2 motorcycle engines: Stock restrictor 36.5mm to 35mm, modified 37.5mm to 34mm; B.5 restrictor 37.5mm to 33mm. All weights increase 25 lbs.
STU Request to correct E&O advanced aerodynamics #27290wordingneutralSTU wing assembly wording corrected: no part higher than roof height.
B-Spec Request to allow OBX Header for 2007-10 Mini Cooper #26977wordingneutralB-Spec 2007-10 Mini Cooper gains OBX header part #10-2101-2S as permitted E&O.
GT2 TA2 Weight Clarification #27077weightslowerGT2 TA2 cars must weigh minimum 2930 lbs per current Trans Am rules or prior Appendix L.
P2 E&O Transmissions #27006otherslowerP2 cars limited to power application on maximum two wheels, effective 2019-07-01.
STU Remove -2mm penalty from SR20DET Nissan #26982enginefasterSTU Nissan SR20DET removes -2mm penalty in Table B.
STU Request clarification for manifold and throttle in STU #27004inductionfasterSTU alternate intake manifolds now allowed case-by-case instead of prohibited.
P2 Request to restrict all cars #26246weightslowerP2 Enterprise minimum weight increases to 1375 lbs; peak horsepower of sealed ESR engine reduced per CRB specification.
GT2 Request to classify Toyota Supra with 3SGTE engine #25185cars addedneutralGT2 Toyota Supra 3SGTE newly classified at 2900 lbs minimum weight, 43mm restrictor.
GT2 Request to Classify Acura NSX from T1 to GT2? #26121cars addedneutralAcura NSX All Years classified to GT2-ST: 3.5L turbo, 3000 lbs minimum, 43mm restrictor.
GT2 Request for TA2 BOP in GT2 #26509weightslowerGT2 TA2 minimum weight increases from 2830 to 2930 pounds.
STU Request to clarify afterrmarket side skirts exhaust exit #26814wordingneutralSTU aftermarket side skirts must meet 3-inch ride height, no openings except jacks or side exhaust, no wider than fascias, not higher than door bottom, no chassis reinforcement.
STU Wheel Flare wording #26872wordingneutralSTU fender flare wording clarified: each fender may be flared up to 2" for tire clearance with 1% weight penalty.
GT2 Request for e36/e46 bmw 4500 cc v8 at 2950lbs in GT2/ST #26106cars addedneutralGT2 BMW E36/E46 4.5L V8 classified at 2950 lbs minimum weight.
GT2 Request GTX Fuel injection for previous GT-1 tube frame cars #26141inductionfasterGTX tube frame cars gain fuel injection with 90mm maximum throttle body size.
GT2 Request to Classify Ligier JS2 R #26535cars addedneutralLigier JS2 R classified in GTX, no performance parameters specified in filing.
STU Request Ride Height Clarification #26597wordingneutralSTL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld.
GT2 Request Ford Perfomance 5.2L crate engine FPR clarification #26159cars addedneutralGT2 Ford Mustang 5.2L classified at 3300 lbs minimum with 82mm single throttle body restrictor.
GT2 Request Ride Height Clarification #26600wordingneutralGT1 and GT2/GT3/LITE ride height requirements removed from GCR sections 9.1.2.D.5.a.1 and 9.1.2.F.7.b.
STU Request to Use Japanese Mazda 13b Intake Manifold #25790inductionfasterSTU Mazda 13B Bridge Port may use ELITE ROTARY SHOP FD V2.0 intake manifold instead of stock.
STU Request Alternate Intake for Mazda MZR In a Rear Wheel Drive App. #26352inductionunclearSTU Mazda MZR LF/L3/L5 may use Goodwin Part #61-2510 intake manifold with stock or Acura throttle body.
STU E&O Suspension #26424wordingneutralSTU suspension rules clarified: alternate components from same manufacturer moved from section E to section D.
STU Revisit B20 VTEC #26530enginefasterSTU Honda/Acura B20 classified at 1973 cc, now permits VTEC B16 or B18 cylinder head and intake manifold.
STU Move Flared Fenders to STU Advanced Aero #26564aeroneutralSTU flared fenders up to 2" with 1% weight penalty moved from base to Advanced Aero rules.
STU TCA Civic SI E&O #26606tyres & wheelsslowerTCA Honda Civic Si (2017-) must run 37mm TIR maximum as of June 1, 2019.
STU S54 Spec line #26620wordingneutralSTU BMW S54B32 OEM reclassified from E46 designation, 3246 cc, 3300 lbs minimum weight.
B-Spec Request to add B-Spec to GCR 9.3.26 fuel cell #26132wordingneutralB-Spec added to GCR 9.3.26 fuel cell exception list; stock fuel tank permitted.
GT2 Request Porsche Cayman year classification #26241wordingneutralGT2 Porsche Cayman model years change from 05-11 to 05-15.
P2 Change Engine Table Lines B.1 & B.5 #25777inductionslowerP2 stock engine restrictor shrinks to 35.0mm and weight rises to 1025 lbs; modified engine restrictor to 34.0mm, weight to 1125 lbs; line B.5 restrictor to 33.0mm, weight to 1185 lbs.
P2 Change Line A.1 restrictor size #26429inductionslowerP2 Line A.1 restrictor reduced from 40mm to 38mm.
STU Request to Class Assignment for 2017 Civic #24287cars addedneutralHonda Civic Si 2017- classified STU at 1500cc, 2800 lbs minimum with OEM engine and bodywork.
STU Request to run E46 3246cc in STU #25126cars addedneutralSTU BMW E46 S54 OEM 3246cc added at 3300 lbs minimum weight, no Super Touring allowances.
STU Engine Classification for Rotary #25564wordingunclearSTU Mazda 13B and 13B Bridge Port may use RE or REW housings and intake with turbo removed.
STU K24/K20 Head Swap Clarification/Amendment #25899wordingneutralSTU Honda K24 may use intake part #s 17100-RRB-A00 or 17100-PRB-A10.
STU Request to Classify 12a Bridge Ported Rotary Engine #25985cars addedneutralSTU Mazda 12A Bridge Port engine classified at 2550 lbs minimum weight with specified carburetor induction options.
STU World Challenge Car Eligibility #26387wordingunclearSTU World Challenge car weight calculation method removed; new basis unclear from text provided.
STU Request a phone call for discussion regarding weight #26398inductionfasterSTU AWD cars no longer required to reduce restrictor 1 mm from table.
STU Advanced Aero E&O #26413aeroneutralSTU rear wing maximum cord length set to 12 inches, end plates to 72.0 square inches each.
B-Spec Request to classify Canadian Nissan Micra Cup cars #25216cars addedneutralCanadian Nissan Micra Cup Car classified in B-Spec at 2450 lbs with 1598cc engine, Micra Cup suspension kit allowed.
B-Spec Request updated Toyota Yaris Spec Lines #25483cars addedneutralToyota Yaris (12-18) newly classified in B-Spec with 1491cc engine, 2400 lbs minimum weight, specified suspension and intake allowed.
B-Spec Update wording of exhaust #26022wordingneutralB-Spec exhaust system wording clarified: OEM or exact replacement catalysts permitted, stock oxygen sensors required, primary converter unmodified.
GT2 ST/GT2 BMW Flossman Kit Clarification #22138wordingunclearGT2 BMW E46 M3, E36, Z3, and 5000cc V8 now permit Flossman body kit.
GT2 Request Clarification/Revision of Appendix L (2013 TA2 Rules) #25110otherfasterGT2 TA2 cars: wheels cost cap drops to $175 each, carbon fiber allowed on rear wing, engine setback maximum 21.75 inches (A-F) or 24 inches (G), various nomenclature and clarification updates.
GT2 Request to classify BMW E82 (1 series) into GT2 #25539cars addedneutralBMW 1 Series E82 classified into GT2 with N52B30 engine, 2996 cc, 2140 lbs minimum weight.
GT2 2010 Cayman Street Tuner Into an STO Car,Addendum #25545weightfasterGT2 Porsche Cayman 05-11 base weight drops 75 lbs to 2800; adds STO/X51 motor notes.
GT2 Request - Classify Ford Performance 5.2l #25716cars addedneutralGT2 Ford Mustang 05- with 5.2L Aluminator engine classified: 3400 lbs minimum weight, 2×41mm flat plate restrictor.
GT2 Add missing displacement, minimum weight. Remove #25765wordingneutralGT2 Porsche 996/997.1 GT3 Cup adds 3.6L displacement and 2900 lbs minimum weight; removes aftermarket exhaust header allowance for 996.
GT2 Request for Ford FP 350s Weight Reduction #25806weightfasterGT2 Ford Mustang FP350S minimum weight reduced 100 lbs, to 3400.
GT2 Request to Classify EcoBoost Mustang #25842cars addedneutralGT2 Ford Mustang 05- EcoBoost classified: 3500cc, 3200 lbs minimum, 41mm restrictor.
GT2 Request to Remove Mazda RX 7 Body Work Penalty #26024weightfasterGT2 Mazda RX7 Downing GTS body kit allowed without 75 lbs. weight penalty.
GT2 GTX Homologation table update #26034cars addedneutralGTX FIA GT3: Audi R8 40mm restrictor 2900 lbs, BMW Z4 70mm 2800 lbs, Ferrari 488 35mm restrictor 3025 lbs classified.
P2 Request to Allow 1345cc Hayabusa Engines for Spec Line P2 Cars #25595enginefasterP2 Spec Line cars now allow 1345cc Hayabusa stock engines at 1050 lbs with 30mm restrictor.
P2 Change CN inlet restrictor implementation date #25816wordingneutralP2 Group CN Honda K20A-FD2 55mm restrictor implementation delayed from 1/1/2019 to 3/1/2019.
P2 Clarify Honda K20A-FD2 parts requirement #25950inductionslowerP2 Honda K20A-FD2 in CN chassis must use stock intake manifold with 64mm throttle body and 55mm restrictor at 1500 lbs minimum weight.
STU Request to Equalize Direct Injected Turbo Cars #24890cars addedneutralSTU Honda K20C1 Turbo I4 1996cc added at 3025 lbs minimum weight with 36mm TIR.
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 B-Spec" is the class's best as a share of B-Spec'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 B-Spec'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.