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BoP Lab / Classes / GT3

GT3 vs FM vs SM vs FE2 pace at every track

Lap times across years say as much about the weather as the class. % of GT3 is each class's best lap as a share of GT3's on the same day, so the conditions drop out: 100% is level, less is quicker, and a move in it is the class getting faster or slower against the field.

Class · click a class to switch, + to compare alongside (up to 4: remove one to add another)
Series
Reference class · the yardstick the % column and chart are measured against
Tracks · untick to narrow

Quickest here: GT3 1:30.797 Gary Bockman, Runoffs 2016 qualifying · FM 1:26.043 Jacob Loomis, Runoffs 2016 qualifying · SM 1:40.514 Justin Hille, Runoffs 2016 qualifying · FE2 1:35.040 Flinn Lazier, Runoffs 2018 qualifying

1:402:002:202:4012 rule changes between Runoffs 2018 and Runoffs 201912 ▾21 rule changes between Runoffs 2019 and Runoffs 202021 ▾7 rule changes between Runoffs 2020 and Runoffs 20217 ▾18 rule changes between Runoffs 2021 and Runoffs 202218 ▾11 rule changes between Runoffs 2022 and Runoffs 202311 ▾34 rule changes between Runoffs 2023 and Runoffs 202434 ▾14 rule changes between Runoffs 2024 and Runoffs 202514 ▾5 rule changes between Runoffs 2025 and Runoffs 20265 ▾GT3 race best at Runoffs 2015: 2:03.617 (Joe Kristensen)GT3 race best at Runoffs 2016: 1:31.107 (Joe Kristensen)GT3 race best at Runoffs 2017: 1:46.330 (Collin Jackson)GT3 race best at Runoffs 2018: 1:42.634 (Michael Lewis)GT3 race best at Runoffs 2019: 1:59.045 (Tony Ave)GT3 race best at Runoffs 2020: 2:24.231 (Tony Ave)GT3 race best at Runoffs 2021: 1:46.694 (Troy Ermish)GT3 race best at Runoffs 2022: 2:24.347 (Tony Ave)GT3 race best at Runoffs 2023: 1:59.872 (Tony Ave)GT3 race best at Runoffs 2024: 2:22.863 (Tony Ave)GT3 qualifying best at Runoffs 2015: 2:01.736 (Joe Kristensen)GT3 qualifying best at Runoffs 2016: 1:30.797 (Gary Bockman)GT3 qualifying best at Runoffs 2017: 1:44.579 (Collin Jackson)GT3 qualifying best at Runoffs 2018: 1:40.947 (Michael Lewis)GT3 qualifying best at Runoffs 2019: 1:58.194 (Michael Lewis)GT3 qualifying best at Runoffs 2020: 2:21.882 (Michael Lewis)GT3 qualifying best at Runoffs 2021: 1:44.758 (Troy Ermish)GT3 qualifying best at Runoffs 2022: 1:57.135 (Jeff Dernehl)GT3 qualifying best at Runoffs 2023: 1:58.065 (Tony Ave)GT3 qualifying best at Runoffs 2024: 2:22.108 (Tony Ave)FM race best at Runoffs 2015: 1:58.029 (Joseph Burton-Harris)FM race best at Runoffs 2016: 1:27.922 (Jacob Loomis)FM race best at Runoffs 2017: 1:41.146 (Jarret Voorhies)FM race best at Runoffs 2018: 1:37.909 (Bryce Cornet)FM race best at Runoffs 2019: 2:15.816 (Bryce Cornet)FM qualifying best at Runoffs 2015: 1:57.804 (Joseph Burton-Harris)FM qualifying best at Runoffs 2016: 1:26.043 (Jacob Loomis)FM qualifying best at Runoffs 2017: 1:41.231 (Jarret Voorhies)FM qualifying best at Runoffs 2018: 1:37.598 (Bryce Cornet)FM qualifying best at Runoffs 2019: 1:55.124 (Bryce Cornet)SM race best at Runoffs 2015: 2:24.067 (Todd Lamb)SM race best at Runoffs 2016: 1:40.764 (Michael Carter)SM race best at Runoffs 2017: 1:59.100 (Michael Gagliardo)SM race best at Runoffs 2018: 1:55.278 (Michael Carter)SM race best at Runoffs 2019: 2:16.459 (Elivan Goulart)SM race best at Runoffs 2020: 2:43.748 (Preston Pardus)SM race best at Runoffs 2021: 1:58.837 (Brian Henderson)SM race best at Runoffs 2022: 2:19.107 (Travis Wiley)SM race best at Runoffs 2023: 2:16.229 (Julian DaCosta)SM race best at Runoffs 2024: 2:41.486 (Brett Kowalski)SM race best at Runoffs 2025: 2:44.430 (Kyle Greenhill)SM race best at Runoffs 2026: 2:42.725 (Francisco Barroso)SM qualifying best at Runoffs 2015: 2:18.661 (Andrew Carbonell)SM qualifying best at Runoffs 2016: 1:40.514 (Justin Hille)SM qualifying best at Runoffs 2017: 1:58.306 (Chris Haldeman)SM qualifying best at Runoffs 2018: 1:54.355 (Ken Sutherland)SM qualifying best at Runoffs 2019: 2:14.552 (Todd Buras)SM qualifying best at Runoffs 2020: 2:42.209 (Kyle Greenhill)SM qualifying best at Runoffs 2021: 1:57.695 (Brian Henderson)SM qualifying best at Runoffs 2022: 2:14.664 (Danny Steyn)SM qualifying best at Runoffs 2023: 2:14.986 (Danny Steyn)SM qualifying best at Runoffs 2024: 2:41.106 (Ethan Goulart)SM qualifying best at Runoffs 2025: 2:43.111 (Bobby Gossett)SM qualifying best at Runoffs 2026: 2:42.173 (Brett Kowalski)FE2 race best at Runoffs 2018: 1:35.563 (Flinn Lazier)FE2 race best at Runoffs 2019: 1:52.154 (Liam Snyder)FE2 race best at Runoffs 2020: 2:13.271 (Owen McAllister)FE2 race best at Runoffs 2021: 1:36.655 (Max Grau)FE2 race best at Runoffs 2022: 2:12.045 (Jason Conzo)FE2 race best at Runoffs 2023: 1:51.098 (Franklin Futrelle)FE2 race best at Runoffs 2024: 2:12.748 (Porter Aiken)FE2 race best at Runoffs 2025: 2:13.339 (Franklin Futrelle)FE2 race best at Runoffs 2026: 2:11.881 (Franklin Futrelle)FE2 qualifying best at Runoffs 2018: 1:35.040 (Flinn Lazier)FE2 qualifying best at Runoffs 2019: 1:51.062 (Liam Snyder)FE2 qualifying best at Runoffs 2020: 2:12.806 (Scott Rettich)FE2 qualifying best at Runoffs 2021: 1:36.395 (Max Grau)FE2 qualifying best at Runoffs 2022: 1:50.853 (Charles Russell Turner)FE2 qualifying best at Runoffs 2023: 1:50.665 (Charles Russell Turner)FE2 qualifying best at Runoffs 2024: 2:11.506 (Porter Aiken)FE2 qualifying best at Runoffs 2025: 2:12.475 (Franklin Futrelle)FE2 qualifying best at Runoffs 2026: 2:12.326 (Franklin Futrelle)Daytona International Speedway · Runoffs 2015R2015Mid-Ohio Sports Car Course · Runoffs 2016R2016Indianapolis Motor Speedway · Runoffs 2017R2017Sonoma Raceway · Runoffs 2018R2018Virginia International Raceway · Runoffs 2019R2019Road America · Runoffs 2020R2020Indianapolis Motor Speedway · Runoffs 2021R2021Virginia International Raceway · Runoffs 2022R2022Virginia International Raceway · Runoffs 2023R2023Road America · Runoffs 2024R2024Road America · Runoffs 2025R2025Road America · Runoffs 2026R2026
GT3FMSMFE2solid race · dashed qualifying · slower is lower
90%95%100%105%110%115%12 rule changes between Runoffs 2018 and Runoffs 201912 ▾21 rule changes between Runoffs 2019 and Runoffs 202021 ▾7 rule changes between Runoffs 2020 and Runoffs 20217 ▾18 rule changes between Runoffs 2021 and Runoffs 202218 ▾11 rule changes between Runoffs 2022 and Runoffs 202311 ▾34 rule changes between Runoffs 2023 and Runoffs 202434 ▾14 rule changes between Runoffs 2024 and Runoffs 202514 ▾5 rule changes between Runoffs 2025 and Runoffs 20265 ▾GT3 race best at Runoffs 2015: 100.0% of GT3's (Joe Kristensen)GT3 race best at Runoffs 2016: 100.0% of GT3's (Joe Kristensen)GT3 race best at Runoffs 2017: 100.0% of GT3's (Collin Jackson)GT3 race best at Runoffs 2018: 100.0% of GT3's (Michael Lewis)GT3 race best at Runoffs 2019: 100.0% of GT3's (Tony Ave)GT3 race best at Runoffs 2020: 100.0% of GT3's (Tony Ave)GT3 race best at Runoffs 2021: 100.0% of GT3's (Troy Ermish)GT3 race best at Runoffs 2022: 100.0% of GT3's (Tony Ave)GT3 race best at Runoffs 2023: 100.0% of GT3's (Tony Ave)GT3 race best at Runoffs 2024: 100.0% of GT3's (Tony Ave)GT3 qualifying best at Runoffs 2015: 100.0% of GT3's (Joe Kristensen)GT3 qualifying best at Runoffs 2016: 100.0% of GT3's (Gary Bockman)GT3 qualifying best at Runoffs 2017: 100.0% of GT3's (Collin Jackson)GT3 qualifying best at Runoffs 2018: 100.0% of GT3's (Michael Lewis)GT3 qualifying best at Runoffs 2019: 100.0% of GT3's (Michael Lewis)GT3 qualifying best at Runoffs 2020: 100.0% of GT3's (Michael Lewis)GT3 qualifying best at Runoffs 2021: 100.0% of GT3's (Troy Ermish)GT3 qualifying best at Runoffs 2022: 100.0% of GT3's (Jeff Dernehl)GT3 qualifying best at Runoffs 2023: 100.0% of GT3's (Tony Ave)GT3 qualifying best at Runoffs 2024: 100.0% of GT3's (Tony Ave)FM race best at Runoffs 2015: 95.5% of GT3's (Joseph Burton-Harris)FM race best at Runoffs 2016: 96.5% of GT3's (Jacob Loomis)FM race best at Runoffs 2017: 95.1% of GT3's (Jarret Voorhies)FM race best at Runoffs 2018: 95.4% of GT3's (Bryce Cornet)FM race best at Runoffs 2019: 114.1% of GT3's (Bryce Cornet)FM qualifying best at Runoffs 2015: 96.8% of GT3's (Joseph Burton-Harris)FM qualifying best at Runoffs 2016: 94.8% of GT3's (Jacob Loomis)FM qualifying best at Runoffs 2017: 96.8% of GT3's (Jarret Voorhies)FM qualifying best at Runoffs 2018: 96.7% of GT3's (Bryce Cornet)FM qualifying best at Runoffs 2019: 97.4% of GT3's (Bryce Cornet)SM race best at Runoffs 2015: 116.5% of GT3's (Todd Lamb)SM race best at Runoffs 2016: 110.6% of GT3's (Michael Carter)SM race best at Runoffs 2017: 112.0% of GT3's (Michael Gagliardo)SM race best at Runoffs 2018: 112.3% of GT3's (Michael Carter)SM race best at Runoffs 2019: 114.6% of GT3's (Elivan Goulart)SM race best at Runoffs 2020: 113.5% of GT3's (Preston Pardus)SM race best at Runoffs 2021: 111.4% of GT3's (Brian Henderson)SM race best at Runoffs 2022: 96.4% of GT3's (Travis Wiley)SM race best at Runoffs 2023: 113.6% of GT3's (Julian DaCosta)SM race best at Runoffs 2024: 113.0% of GT3's (Brett Kowalski)SM qualifying best at Runoffs 2015: 113.9% of GT3's (Andrew Carbonell)SM qualifying best at Runoffs 2016: 110.7% of GT3's (Justin Hille)SM qualifying best at Runoffs 2017: 113.1% of GT3's (Chris Haldeman)SM qualifying best at Runoffs 2018: 113.3% of GT3's (Ken Sutherland)SM qualifying best at Runoffs 2019: 113.8% of GT3's (Todd Buras)SM qualifying best at Runoffs 2020: 114.3% of GT3's (Kyle Greenhill)SM qualifying best at Runoffs 2021: 112.3% of GT3's (Brian Henderson)SM qualifying best at Runoffs 2022: 115.0% of GT3's (Danny Steyn)SM qualifying best at Runoffs 2023: 114.3% of GT3's (Danny Steyn)SM qualifying best at Runoffs 2024: 113.4% of GT3's (Ethan Goulart)FE2 race best at Runoffs 2018: 93.1% of GT3's (Flinn Lazier)FE2 race best at Runoffs 2019: 94.2% of GT3's (Liam Snyder)FE2 race best at Runoffs 2020: 92.4% of GT3's (Owen McAllister)FE2 race best at Runoffs 2021: 90.6% of GT3's (Max Grau)FE2 race best at Runoffs 2022: 91.5% of GT3's (Jason Conzo)FE2 race best at Runoffs 2023: 92.7% of GT3's (Franklin Futrelle)FE2 race best at Runoffs 2024: 92.9% of GT3's (Porter Aiken)FE2 qualifying best at Runoffs 2018: 94.1% of GT3's (Flinn Lazier)FE2 qualifying best at Runoffs 2019: 94.0% of GT3's (Liam Snyder)FE2 qualifying best at Runoffs 2020: 93.6% of GT3's (Scott Rettich)FE2 qualifying best at Runoffs 2021: 92.0% of GT3's (Max Grau)FE2 qualifying best at Runoffs 2022: 94.6% of GT3's (Charles Russell Turner)FE2 qualifying best at Runoffs 2023: 93.7% of GT3's (Charles Russell Turner)FE2 qualifying best at Runoffs 2024: 92.5% of GT3's (Porter Aiken)Daytona International Speedway · Runoffs 2015R2015Mid-Ohio Sports Car Course · Runoffs 2016R2016Indianapolis Motor Speedway · Runoffs 2017R2017Sonoma Raceway · Runoffs 2018R2018Virginia International Raceway · Runoffs 2019R2019Road America · Runoffs 2020R2020Indianapolis Motor Speedway · Runoffs 2021R2021Virginia International Raceway · Runoffs 2022R2022Virginia International Raceway · Runoffs 2023R2023Road America · Runoffs 2024R2024Road America · Runoffs 2025R2025Road America · Runoffs 2026R2026
GT3FMSMFE2solid race · dashed qualifying · each class's best lap as a share of GT3's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker
EventGT3FMSMFE2
Qual bestRace bestTrapQual bestRace bestTrapvs GT3% of GT3Qual bestRace bestTrapvs GT3% of GT3Qual bestRace bestTrapvs GT3% of GT3
Road America Runoffs 20262026-09-282:42.173Brett Kowalski · fastest of 34 · top 5 within 0.3s-0.938s (-0.58%)2:42.725Francisco Barroso · fastest of 35 · top 5 within 0.2s-1.705s (-1.04%)119.6Wyatt Couch+0.3 mph (+0.3%)2:12.326Franklin Futrelle · fastest of 8 · top 5 within 1.9s-0.149s (-0.11%)2:11.881Franklin Futrelle · fastest of 8 · top 5 within 1.6s-1.458s (-1.09%)143.5Steve Whitston-5.5 mph (-3.7%)
5 rule changes (GT3: 2, SM: 2, FE2: 1)2 cars added · 1 suspension & brakes · 1 wording · 1 other · SM/SMX Mazda rear toe link part number revised from 0000-04-5361426 to 0000-04-5361. · SM/SMX part number 0000-10-6900 replaced with 0000-06-5016-KT in GCR 9.1.7.C.1.j.1.c. · GT3U class removed from GCR; GT3U cars now compete in STU. · GT3U cars must meet 3.0" minimum ride height on frame rails and 2.0" on front spoiler and splitter. · FE and FE2 Enterprise bubble tail part WM138014 now allowed; FE2 must use this configuration only.showhide
  • SM Rear Toe Link #40271wordingwordingSM/SMX Mazda rear toe link part number revised from 0000-04-5361426 to 0000-04-5361.
  • SM Part Number Change Request #39914otherunclearSM/SMX part number 0000-10-6900 replaced with 0000-06-5016-KT in GCR 9.1.7.C.1.j.1.c.
  • GT3 Remove GT3U from GCR as it is now in STU #39862cars addedremoved · cars addedGT3U class removed from GCR; GT3U cars now compete in STU.
  • GT3 GT3U Ride Height #39637suspension & brakesadded · suspension & brakesGT3U cars must meet 3.0" minimum ride height on frame rails and 2.0" on front spoiler and splitter.
  • FE2 FE & FE2 Bubble Tail #38978cars addedaddedFE and FE2 Enterprise bubble tail part WM138014 now allowed; FE2 must use this configuration only.
Road America Runoffs 20252025-09-292:43.111Bobby Gossett · fastest of 32 · top 5 within 0.3s+2.005s (+1.24%)2:44.430Kyle Greenhill · fastest of 28 · top 5 within 0.3s+2.944s (+1.82%)119.3Francisco Barroso-0.6 mph (-0.5%)2:12.475Franklin Futrelle · fastest of 11 · top 5 within 1.4s+0.969s (+0.74%)2:13.339Franklin Futrelle · fastest of 10 · top 5 within 0.6s+0.591s (+0.45%)149.0Steve Whitston+3.7 mph (+2.6%)
14 rule changes (GT3: 9, SM: 4, FE2: 1)7 weight · 1 cars added · 4 wording · 2 other · GT3U cars with 15x7 wheels gain 225 lbs; optional 15x9 wheels add 1.5% weight, 18x9 wheels add 3.0%. TCR cars now ineligible for GT3/GT3U. · SMX drivers must submit data acquisition files on time or face suspension and $250 fine. · SMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fines, level 2 and 4 may carry $500 fines. · GT3U with 15"x7" wheels and 225 section tires now runs plus 225 lbs instead of plus 150 lbs; wheel and weight options clarified. · SM tire marking rules clarified: one Hoosier SM 7.5 P205/50/ZR17 set per Super Tour weekend, impound after first dry session, damaged tires may be replaced with used tires only. · FE2 allows pre-approved driver safety and comfort seat and control modifications for drivers with disabilities, per logbook. · TA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof height limit. · GT3 VW Fun Cup Beetle exempted from 150 lbs consolidation add-on weight. · GT3 Pontiac LE5 Ecotech minimum weight drops 150 lbs to 2195. · SMX OE instrument cluster must stay unmodified and connected; aftermarket dash allowed if wiring only re-routed; alternate gauges now permitted; foot pedal comfort mods allowed without relocation. · GT3 Mazda 13B Bridgeport and Peripheral Port minimum weights drop to 2275 lbs. · GT3 adds Nissan MR20DE DOHC engine, 1997cc, 32mm SIR, 2060 lbs minimum weight. · GT3 Mazda 13B minimum weight drops from 2350 to 2175 lbs; disfranchised GT2 baseline now 2175 lbs. · GT3 Mazda 12A peripheral port minimum weight reduced 200 lbs to 2100.showhide
  • GT3 Declassify TCR Cars from GT3/GT3U #38569weightslower · weightGT3U cars with 15x7 wheels gain 225 lbs; optional 15x9 wheels add 1.5% weight, 18x9 wheels add 3.0%. TCR cars now ineligible for GT3/GT3U.
  • SM SMX Data Submission - Penalties #38248otheraddedSMX drivers must submit data acquisition files on time or face suspension and $250 fine.
  • SM Committee) SMX Penaly Clarification updated language #38337wordingwordingSMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fines, level 2 and 4 may carry $500 fines.
  • GT3 Clarification of GT3U #38266weightslower · weightGT3U with 15"x7" wheels and 225 section tires now runs plus 225 lbs instead of plus 150 lbs; wheel and weight options clarified.
  • SM Clarify Tire Marking Regs #38005wordingwordingSM tire marking rules clarified: one Hoosier SM 7.5 P205/50/ZR17 set per Super Tour weekend, impound after first dry session, damaged tires may be replaced with used tires only.
  • FE2 Driver Safety & Comfort #37965otheraddedFE2 allows pre-approved driver safety and comfort seat and control modifications for drivers with disabilities, per logbook.
  • GT3 Correct language regarding OEM Areo Devices #37137wordingwordingTA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof height limit.
  • GT3 VW Funcap weight #37217weightfaster · weightGT3 VW Fun Cup Beetle exempted from 150 lbs consolidation add-on weight.
  • GT3 Pontiac Weight and Chassis Adjustment Request #36938weight -150 lbsfaster · weightGT3 Pontiac LE5 Ecotech minimum weight drops 150 lbs to 2195.
  • SM E&O SMX Regs 9.1.7.1.D.5.u-.w #37070wordingwordingSMX OE instrument cluster must stay unmodified and connected; aftermarket dash allowed if wiring only re-routed; alternate gauges now permitted; foot pedal comfort mods allowed without relocation.
  • GT3 GCR GT3 Disfranchised GT2 #36291weight -75 lbsfaster · weightGT3 Mazda 13B Bridgeport and Peripheral Port minimum weights drop to 2275 lbs.
  • GT3 Nissan MR20DE Engine Classification Request for GT3 #36791cars addedaddedGT3 adds Nissan MR20DE DOHC engine, 1997cc, 32mm SIR, 2060 lbs minimum weight.
  • GT3 GT3 Mazda 13B PP correction #37057weight -175 lbsfaster · weightGT3 Mazda 13B minimum weight drops from 2350 to 2175 lbs; disfranchised GT2 baseline now 2175 lbs.
  • GT3 GT3 Mazda12A PP Correction #37058weight -200 lbsfaster · weightGT3 Mazda 12A peripheral port minimum weight reduced 200 lbs to 2100.
Road America Runoffs 20242024-10-012:22.108Tony Ave · fastest of 13 · top 5 within 3.7s+0.226s (+0.16%)2:22.863Tony Ave · fastest of 13 · top 5 within 3.3s-1.368s (-0.95%)151.2Jeff Dernehl+1.8 mph (+1.2%)2:41.106Ethan Goulart · fastest of 49 · top 5 within 0.5s-1.103s (-0.68%)2:41.486Brett Kowalski · fastest of 43 · top 5 within 0.3s-2.262s (-1.38%)119.9Alex Bertagnoli-1.4 mph (-1.2%)+18.623squal +18.998s113.0%qual 113.4%2:11.506Porter Aiken · fastest of 18 · top 5 within 0.5s-1.300s (-0.98%)2:12.748Porter Aiken · fastest of 17 · top 5 within 2.0s-0.523s (-0.39%)145.3Porter Aiken+1.9 mph (+1.3%)-10.115squal -10.602s92.9%qual 92.5%
34 rule changes (GT3: 30, SM: 4)8 weight · 6 cars added · 5 engine · 3 aero · 1 induction · 1 tyres & wheels · 8 wording · 2 other · GT3 Mazda 3TC added to TCR spec line at 2950 lbs, must conform to 2024 TC Car specs. · SMX Spec MX-5 camera requirement: non-functioning recorder now will instead of may warrant penalty or disqualification. · SM and SMX must run latest AIM Data Logger Spec MX-5 ECU Protocol, effective 2024-09-01. · SMX Mazda MX-5 OE versus OEM definitions clarified in GCR section 9.1.7.1; wording change only. · SM and SMX now allow an alternate shifter bushing at the bottom of the shift lever. · GT3 adds Nissan 1200 (B110) 70–73, must use GT3-classified engine or request alternate Nissan engine. · GT3-TCR Honda Civic Type R SEQ minimum weight raised to 3210 lbs; Hyundai I30N and VW GTI SEQ reduced 100 lbs each. · GT3 Pontiac Sunfire GT weight reduction note changes from 150 to 75. · GT3 Mazda MZR removes second DOHC option, fuel induction now unrestricted. · GT3 cars may run +1mm SIR above spec with 175 lb weight penalty. · GT3 turbocharged 1401–1850 cc four-valve engine with 34 mm restrictor drops to 2250 lbs minimum weight. · GT2-ST Acura NSX minimum weight rises to 3000 lbs, restrictor increases to 45mm TIR. · GT3 Ford Duratech engine now allows hood bulge with no openings. · GT3 Acura K20A RSX body adds 75 lbs for disenfranchised GT2 entries. · GT3 Toyota 4Y engine added: 2237cc OHV, 2030 lbs minimum weight, unrestricted fuel induction. · GT3 Toyota model designation changed from DR86 to GR86. · GT3 Honda K20C1 and K24 engines have spec line designations clarified, removing bore and displacement references. · GT3 Mazda spec line reorganized: model column heading, 323 and 626 designations, weight figures updated. · GT3 Miata Turbo restrictor increases to 35 mm, minimum weight rises to 2350 lbs. · GT1-GTX rear blade spoiler: angle 50–75°, max 59.0 wide by 5.0 high inches; total area limit removed. · GT1, GT2, GT3, GTL, GTX Direct Injection now permitted if original equipment. · GT3 Toyota FA24D 2387cc DOHC engine added, 2195 lbs, direct injection permitted. · GT2 Nissan and GT3 Mazda, Mitsubishi 4G93, Nissan QR25DE/DD, QE25DE/DD now permit Direct Injection per 9.1.2.F.7.5.E. · GT3 Nissan QR25DE/DD spec line edit appears corrupted; text unreadable. · GT3 Mazda RX7 12A, 13B Bridgeport, 13B Peripheral Port: disenfranchised GT2 cars add 75 lbs. · GT3 Mazda BP4W turbocharged engine minimum weight reduced 100 lbs to 1960. · GT3 Mazda 13B peripheral port minimum weight reduced to 2100 lbs. · Toyota GR 86 DR86 2021–2024 added to GT3 as rear-wheel-drive coupe, 101.3 in wheelbase. · GT3 Toyota 3S bore increases to 86.0 mm, stroke decreases to 86.0 mm. · GT3 Toyota 3S DOHC engine classified at 1998 cc, 1960 lbs minimum weight, unrestricted fuel induction. · GT3 2.0L SIR engines remove 32mm restrictor option and 2195 lbs unrestricted weight allowance for all listed makes. · GTL spec lines moved contiguous with GT2 and GT3; GTA category and specs renumbered behind GTL; P2 engine tables reorganised with restrictor and weight specifications clarified. · GT3-TCR Audi RS3 LMS, Honda Civic Type R, Hyundai i30 N, VW Golf GTi must use 200 tread wear any DOT tires. · GT3 Honda B20 engine classified for use; 1973cc DOHC with 84mm bore, 89mm stroke, aluminum head.showhide
  • GT3 2024 Mazda 3 TC request for GT3 #36517cars addedaddedGT3 Mazda 3TC added to TCR spec line at 2950 lbs, must conform to 2024 TC Car specs.
  • SM SMX Camera Rule Correction #36496wordingwordingSMX Spec MX-5 camera requirement: non-functioning recorder now will instead of may warrant penalty or disqualification.
  • SM Committee) AIM ECU Protocol #36556engineadded · engineSM and SMX must run latest AIM Data Logger Spec MX-5 ECU Protocol, effective 2024-09-01.
  • SM Committee) OE versus OEM Definitons #36608wordingwordingSMX Mazda MX-5 OE versus OEM definitions clarified in GCR section 9.1.7.1; wording change only.
  • SM Committee) Shifter Bushing #36611otheraddedSM and SMX now allow an alternate shifter bushing at the bottom of the shift lever.
  • GT3 Adding Datsun B110 to List of Approved Cars #36198cars addedaddedGT3 adds Nissan 1200 (B110) 70–73, must use GT3-classified engine or request alternate Nissan engine.
  • GT3 Honda Civic Type R TCR Weight Reduction Request #36550weightslower · weightGT3-TCR Honda Civic Type R SEQ minimum weight raised to 3210 lbs; Hyundai I30N and VW GTI SEQ reduced 100 lbs each.
  • GT3 Correct missed Disenfranchised weight reduction #36237wordingunclearGT3 Pontiac Sunfire GT weight reduction note changes from 150 to 75.
  • GT3 errors & omissions on GT3 Mazda MZR spec lines #36241wordingunclearGT3 Mazda MZR removes second DOHC option, fuel induction now unrestricted.
  • GT3 GT3 +1mm SIR add 175lbs. In #36098aeroslower · aeroGT3 cars may run +1mm SIR above spec with 175 lb weight penalty.
  • GT3 Revised GT3 Built Turbocharged chart #36100weightfaster · weightGT3 turbocharged 1401–1850 cc four-valve engine with 34 mm restrictor drops to 2250 lbs minimum weight.
  • GT3 Request for Spec Line 1010 Reconsideration #35009weight +300 lbsslower · weightGT2-ST Acura NSX minimum weight rises to 3000 lbs, restrictor increases to 45mm TIR.
  • GT3 Mazda MZR Engines #35753aeroadded · aeroGT3 Ford Duratech engine now allows hood bulge with no openings.
  • GT3 Disenfranchised GT2 Acura RSX to Run GT3 #35773weightslower · weightGT3 Acura K20A RSX body adds 75 lbs for disenfranchised GT2 entries.
  • GT3 Toyota 4Y Engine Request #35885cars addedaddedGT3 Toyota 4Y engine added: 2237cc OHV, 2030 lbs minimum weight, unrestricted fuel induction.
  • GT3 GT3 spec lines clean-up #36008wordingwordingGT3 Toyota model designation changed from DR86 to GR86.
  • GT3 GT3 Honda spec line clean-up x 2 #36009wordingwordingGT3 Honda K20C1 and K24 engines have spec line designations clarified, removing bore and displacement references.
  • GT3 GT3 Mazda spec line clean-up x2 #36010wordingunclearGT3 Mazda spec line reorganized: model column heading, 323 and 626 designations, weight figures updated.
  • GT3 Miata Turbo Clarification #35386weight +100 lbsslower · weightGT3 Miata Turbo restrictor increases to 35 mm, minimum weight rises to 2350 lbs.
  • GT3 Rear Blade Spoiler Clarification #35261aeroaeroGT1-GTX rear blade spoiler: angle 50–75°, max 59.0 wide by 5.0 high inches; total area limit removed.
  • GT3 GT Direct Injection allowance and rules #35437engineadded · engineGT1, GT2, GT3, GTL, GTX Direct Injection now permitted if original equipment.
  • GT3 Request to Include Toyota FA24D Engine for use in GT3 #35199cars addedaddedGT3 Toyota FA24D 2387cc DOHC engine added, 2195 lbs, direct injection permitted.
  • GT3 GT2/3 remove Direction Injection not allowed in Spec line notes #35439engineadded · engineGT2 Nissan and GT3 Mazda, Mitsubishi 4G93, Nissan QR25DE/DD, QE25DE/DD now permit Direct Injection per 9.1.2.F.7.5.E.
  • GT3 Edit GT3 Nissan QR25DE/DD spec line #35442otherunclearGT3 Nissan QR25DE/DD spec line edit appears corrupted; text unreadable.
  • GT3 Disenfranchised GT2 RX7. #35028weightslower · weightGT3 Mazda RX7 12A, 13B Bridgeport, 13B Peripheral Port: disenfranchised GT2 cars add 75 lbs.
  • GT3 Turbo Help #35042weight -100 lbsfaster · weightGT3 Mazda BP4W turbocharged engine minimum weight reduced 100 lbs to 1960.
  • GT3 Competition Adjustment Request for 13B Peripheral Port #35100weight -100 lbsfaster · weightGT3 Mazda 13B peripheral port minimum weight reduced to 2100 lbs.
  • GT3 Request to Include Toyota GR 86 in GT3 #35197cars addedaddedToyota GR 86 DR86 2021–2024 added to GT3 as rear-wheel-drive coupe, 101.3 in wheelbase.
  • GT3 Fastrack Toyota 3S Correction #35258engineunclearGT3 Toyota 3S bore increases to 86.0 mm, stroke decreases to 86.0 mm.
  • GT3 Toyota Engine Classification Request #35019engineadded · engineGT3 Toyota 3S DOHC engine classified at 1998 cc, 1960 lbs minimum weight, unrestricted fuel induction.
  • GT3 GT3 2.0L SIR & weight #35171inductionslower · inductionGT3 2.0L SIR engines remove 32mm restrictor option and 2195 lbs unrestricted weight allowance for all listed makes.
  • GT3 Errors in GTCS Headings and Use of the Terms Category and ClassChange existing GTL and GTA Rules #34453wordingwordingGTL spec lines moved contiguous with GT2 and GT3; GTA category and specs renumbered behind GTL; P2 engine tables reorganised with restrictor and weight specifications clarified.
  • GT3 GT3 TCR 200 TW tires #34993tyres & wheelstyres & wheelsGT3-TCR Audi RS3 LMS, Honda Civic Type R, Hyundai i30 N, VW Golf GTi must use 200 tread wear any DOT tires.
  • GT3 Classify Honda B20 engine in GT3 CRX #34781cars addedaddedGT3 Honda B20 engine classified for use; 1973cc DOHC with 84mm bore, 89mm stroke, aluminum head.
Virginia International Raceway Runoffs 20232023-09-231:58.065Tony Ave · fastest of 9 · top 5 within 3.8s+0.930s (+0.79%)1:59.872Tony Ave · fastest of 8 · top 5 within 3.9s-24.475s (-16.96%)145.8Jeff Dernehl-3.6 mph (-2.4%)2:14.986Danny Steyn · fastest of 52 · top 5 within 0.1s+0.322s (+0.24%)2:16.229Julian DaCosta · fastest of 46 · top 5 within 0.3s-2.878s (-2.07%)120.3Jim Drago+1.1 mph (+0.9%)+16.357squal +16.921s113.6%qual 114.3%1:50.665Charles Russell Turner · fastest of 26 · top 5 within 2.3s-0.188s (-0.17%)1:51.098Franklin Futrelle · fastest of 19 · top 5 within 1.4s-20.947s (-15.86%)141.3Franklin Futrelle-0.6 mph (-0.4%)-8.774squal -7.400s92.7%qual 93.7%
11 rule changes (GT3: 10, SM: 1)3 cars added · 2 engine · 1 induction · 1 tyres & wheels · 1 weight · 2 wording · 1 other · GT3 allows 15" American Racer 23.5-10.0-15 bias ply tires without weight penalty. · Fields Cardinal V8 added to GT1 with Ford V8 engine, 4.9L, 2100 lbs, fuel injection. · GT3 Nissan VG30 engine removed from class. · GT3 normally aspirated cars may now use chokes instead of SIRs, same size as listed SIR, one per carburetor barrel. · GT3 2.0L 4-valve non-turbo engines may run unrestricted at 2060 lbs minimum weight. · SM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore. · GT3 Mazda BP4W Turbocharged OEM engine added, 1839cc, 2060 lbs, with 34mm TIR and IHI RHF5 VJ35 turbo. · GT2 TA2 and GTA throttle body part numbers updated to GM 12570790 or Edelbrock 33869/3870. · GT3 Nissan SR20VET turbo ECU changes from stock only to open, enabling tuning. · GT3 adds 84-87 Honda Civic 3dr FWD, 86.6 in wheelbase, hood bulge allowed. · GT3 turbo maximum engine displacement clarified to 1,401-1,850 cc.showhide
  • GT3 Addendum to letter 33913, GT3 DOT tires. #34627tyres & wheelsfaster · tyres & wheelsGT3 allows 15" American Racer 23.5-10.0-15 bias ply tires without weight penalty.
  • GT3 Please classify Fields Cardinal V8 #33784cars addedaddedFields Cardinal V8 added to GT1 with Ford V8 engine, 4.9L, 2100 lbs, fuel injection.
  • GT3 Remove Nissan VG30 engine from GT3 #33609engineremoved · engineGT3 Nissan VG30 engine removed from class.
  • GT3 GT3 Choke option effective 1-01-2023 #33669inductionadded · inductionGT3 normally aspirated cars may now use chokes instead of SIRs, same size as listed SIR, one per carburetor barrel.
  • GT3 GT3 2.0L choke/weight option #33670otheraddedGT3 2.0L 4-valve non-turbo engines may run unrestricted at 2060 lbs minimum weight.
  • SM BOP for NB1 and NB2 #32309weightslower · weightSM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore.
  • GT3 Turbocharged Engine Rules #33145cars addedaddedGT3 Mazda BP4W Turbocharged OEM engine added, 1839cc, 2060 lbs, with 34mm TIR and IHI RHF5 VJ35 turbo.
  • GT3 GT2 (TA2)/GTA Part Number Update #33315wordingwordingGT2 TA2 and GTA throttle body part numbers updated to GM 12570790 or Edelbrock 33869/3870.
  • GT3 GT3 Nissian SR20VET unrestricted ECU change #33432enginefaster · engineGT3 Nissan SR20VET turbo ECU changes from stock only to open, enabling tuning.
  • GT3 Add 84-87 Civic #33091cars addedaddedGT3 adds 84-87 Honda Civic 3dr FWD, 86.6 in wheelbase, hood bulge allowed.
  • GT3 GT3 Turbo Displacement Clarification #32952wordingwordingGT3 turbo maximum engine displacement clarified to 1,401-1,850 cc.
Virginia International Raceway Runoffs 20222022-09-241:57.135Jeff Dernehl · fastest of 13 · top 5 within 3.2s-1.059s (-0.90%)2:24.347Tony Ave · fastest of 12 · top 5 within 8.2s+25.302s (+21.25%)149.5Jeff Dernehl-0.2 mph (-0.1%)2:14.664Danny Steyn · fastest of 60 · top 5 within 0.2s+0.112s (+0.08%)2:19.107Travis Wiley · fastest of 58 · top 5 within 0.9s+2.648s (+1.94%)119.2Jonathan Neudorf-0.6 mph (-0.5%)-5.240squal +17.529s96.4%qual 115.0%1:50.853Charles Russell Turner · fastest of 25 · top 5 within 1.1s-0.209s (-0.19%)2:12.045Jason Conzo · fastest of 22 · top 5 within 1.8s+19.891s (+17.74%)141.9Eric Cruz-0.6 mph (-0.5%)-12.302squal -6.282s91.5%qual 94.6%
18 rule changes (GT3: 17, SM: 1)10 cars added · 2 engine · 1 tyres & wheels · 1 weight · 4 wording · GT1, GT2, GT3, GTL, GTX tail lights may now be original style or custom panel graphic with functioning red LED brake lamps. · GT3 adds Nissan SR20VET Limited Prep-Turbocharged OEM engine, 1998cc, 2060 lbs, Garrett GT2560LS turbo only. · GT3 Fiat 124 Spider model name corrected from Pininfarina to Pininfarina Spider. · GT3 Fiat 124 Spider Pininfarina classified with body style, drive-line, and wheelbase specifications. · GT3 adds 17x9 wheels with 3% weight penalty, 18" wheels with 5% penalty down from 8%, and 13" brake rotors. · GT3-TCR Audi RS3 SEQ/DSG, Honda Civic, Hyundai i30N, VW Golf GTI SEQ power cut to 90%; weights up 2–54 lbs; VW Golf GTI DSG to 97.5%. · SM Majors must run authorized Penske shock and mount; Regional competitors not required until further evaluation. · GT3 Ginetta G40 classified with Mazda MZR 1999cc at 2060 lbs or Ford Duratec 2260cc at 2195 lbs, both 32mm SIR, 5-speed only. · GT3 Mazda MZR 1999cc DOHC newly classified with 2195 lbs minimum weight, unrestricted fuel induction. · GT3 Volvo S60 2000-2009 four-door sports coupe, front-wheel drive, 106.9 in wheelbase, newly classified. · GT3 2.0L 4V engines may run unrestricted at 2195 lbs minimum weight. · GT3 wing wording corrected; single element airfoil maximum chord length stays 10.75 inches. · GT3 adds Fiat Spider 2000, years 79-81, RWD, 89.76" wheelbase. · GT3 adds Fiat X-19, years 72-89. · GT3 Fun Cup Beetle Sealed minimum weight drops 210 lbs, to 1850. · GT3 adds TCR cars: Audi RS3 LMS, Honda Civic Type R, Hyundai i30N, Volkswagen Golf GTI at 3100–3200 lbs with 200 tread wear tires. · GT3 Ford Cortina GT 1964-1968 added to classified cars list. · GT3 Volkswagen Fun Cup Beetle EVO3 classified, sealed SOHC 1984cc engine, 2060 lbs minimum weight.showhide
  • GT3 Tail lights on all GT category race cars. #32799wordingwordingGT1, GT2, GT3, GTL, GTX tail lights may now be original style or custom panel graphic with functioning red LED brake lamps.
  • GT3 SR20VET Engine Option Request #32648cars addedaddedGT3 adds Nissan SR20VET Limited Prep-Turbocharged OEM engine, 1998cc, 2060 lbs, Garrett GT2560LS turbo only.
  • GT3 Correct Model GT3 - Fiat #32776wordingwordingGT3 Fiat 124 Spider model name corrected from Pininfarina to Pininfarina Spider.
  • GT3 Correct Fiat Spider Years #32149cars addedaddedGT3 Fiat 124 Spider Pininfarina classified with body style, drive-line, and wheelbase specifications.
  • GT3 wheel size addition #32247tyres & wheelsfaster · tyres & wheelsGT3 adds 17x9 wheels with 3% weight penalty, 18" wheels with 5% penalty down from 8%, and 13" brake rotors.
  • GT3 GT3 TCR Car Feedback #31677engine +2 lbsslower · engineGT3-TCR Audi RS3 SEQ/DSG, Honda Civic, Hyundai i30N, VW Golf GTI SEQ power cut to 90%; weights up 2–54 lbs; VW Golf GTI DSG to 97.5%.
  • SM Update GCR Section 9.1.7.3.A.1. #32217wordingwordingSM Majors must run authorized Penske shock and mount; Regional competitors not required until further evaluation.
  • GT3 Request to Classify Ginetta G40 in GT3 #31598cars addedaddedGT3 Ginetta G40 classified with Mazda MZR 1999cc at 2060 lbs or Ford Duratec 2260cc at 2195 lbs, both 32mm SIR, 5-speed only.
  • GT3 Normally Aspirated 2.0L DOHC MZR Motor #31733cars addedaddedGT3 Mazda MZR 1999cc DOHC newly classified with 2195 lbs minimum weight, unrestricted fuel induction.
  • GT3 Volvo S60 in GT3 #31970cars addedaddedGT3 Volvo S60 2000-2009 four-door sports coupe, front-wheel drive, 106.9 in wheelbase, newly classified.
  • GT3 GT3 2.0L 4V engines now unrestricted. #32190enginefaster · engineGT3 2.0L 4V engines may run unrestricted at 2195 lbs minimum weight.
  • GT3 TB correction to wing wording #32191wordingwordingGT3 wing wording corrected; single element airfoil maximum chord length stays 10.75 inches.
  • GT3 Request to add Fiat to GT3 CARS #31803cars addedaddedGT3 adds Fiat Spider 2000, years 79-81, RWD, 89.76" wheelbase.
  • GT3 Request to add Fiat to GT3 CARS #31804cars addedaddedGT3 adds Fiat X-19, years 72-89.
  • GT3 31032 correction to weight #31525weight -210 lbsfaster · weightGT3 Fun Cup Beetle Sealed minimum weight drops 210 lbs, to 1850.
  • GT3 Add TCR cars to GT3 #31540cars addedaddedGT3 adds TCR cars: Audi RS3 LMS, Honda Civic Type R, Hyundai i30N, Volkswagen Golf GTI at 3100–3200 lbs with 200 tread wear tires.
  • GT3 Please approve 1964-1968 Ford Cortina GT for competition in GT# #30941cars addedaddedGT3 Ford Cortina GT 1964-1968 added to classified cars list.
  • GT3 Request car classification #31032cars addedaddedGT3 Volkswagen Fun Cup Beetle EVO3 classified, sealed SOHC 1984cc engine, 2060 lbs minimum weight.
Indianapolis Motor Speedway Runoffs 20212021-09-251:44.758Troy Ermish · fastest of 14 · top 5 within 4.6s+0.179s (+0.17%)1:46.694Troy Ermish · fastest of 13 · top 5 within 4.1s+0.364s (+0.34%)145.8Stacy Wilson1:57.695Brian Henderson · fastest of 90 · top 5 within 0.5s-0.611s (-0.52%)1:58.837Brian Henderson · fastest of 88 · top 5 within 0.3s-0.263s (-0.22%)119.8Kyle Greenhill+12.143squal +12.937s111.4%qual 112.3%1:36.395Max Grau · fastest of 28 · top 5 within 0.7s1:36.655Max Grau · fastest of 28 · top 5 within 0.7s146.2Gray Fowler-10.039squal -8.363s90.6%qual 92.0%
7 rule changes (GT3: 6, SM: 1)3 induction · 2 cars added · 2 wording · GTA part numbers updated: 0-80541-1 to 0-80541-2 in two locations and 6010 to 6014X in TA2 Appendix. · GT3 permits current FP spec line cars to compete while maintaining full FP rule set. · GT3 Mazda MZR 2.0L fuel induction restrictor increases from 31 to 32 mm. · GT3 Mazda Renesis and 13B Bridgeport choke size corrected to 42mm. · SM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture. · GT3 Mazda MZR and MZR/L5-VE fuel induction size increases from 31 to 32. · GT3 Honda Prelude 1992-1997 2dr FWD 104" wheelbase newly classified.showhide
  • GT3 Request to Update GTA Obsolete Part Numbers #30615wordingwordingGTA part numbers updated: 0-80541-1 to 0-80541-2 in two locations and 6010 to 6014X in TA2 Appendix.
  • GT3 Request to Permit FP cars in GT3 #30611cars addedaddedGT3 permits current FP spec line cars to compete while maintaining full FP rule set.
  • GT3 Mazda MZR 2.0L Engine #30455inductionfaster · inductionGT3 Mazda MZR 2.0L fuel induction restrictor increases from 31 to 32 mm.
  • GT3 Disfranchised GT3 Mazda, correct choke size #30570inductioninductionGT3 Mazda Renesis and 13B Bridgeport choke size corrected to 42mm.
  • SM Updates - Obsolete Parts & BOP Parts #30438wordingaddedSM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture.
  • GT3 Mazda MZR SIR Sizing #29555inductionfaster · inductionGT3 Mazda MZR and MZR/L5-VE fuel induction size increases from 31 to 32.
  • GT3 Request to Classify 1992-1997 Honda Prelude #29687cars addedaddedGT3 Honda Prelude 1992-1997 2dr FWD 104" wheelbase newly classified.
Road America Runoffs 20202020-10-022:21.882Michael Lewis · fastest of 12 · top 5 within 3.0s2:24.231Tony Ave · fastest of 12 · top 5 within 3.0s149.5Jeff Dernehl2:42.209Kyle Greenhill · fastest of 77 · top 5 within 0.5s2:43.748Preston Pardus · fastest of 75 · top 5 within 1.0s121.3Kyle Greenhill+19.517squal +20.327s113.5%qual 114.3%2:12.806Scott Rettich · fastest of 25 · top 5 within 0.6s2:13.271Owen McAllister · fastest of 23 · top 5 within 0.7s143.4Owen McAllister-10.960squal -9.076s92.4%qual 93.6%
21 rule changes (GT3: 17, SM: 2, FE2: 2)6 cars added · 4 induction · 1 engine · 1 suspension & brakes · 1 weight · 6 wording · 2 other · SM allows aftermarket radiators in original location with stock OEM cooling fan, and permits 1990-1997 cars to install upper radiator seal NA75-50-OK7A. · FE2 oil cooler rule clarified: Setrab 50-625-7612 or any cooler with max core 13 inches wide by 6.5 inches high allowed. · GT1/GT2/GT3/GTL/GTX turbocharging and supercharging now permitted if listed on spec line. · SM rear brake caliper may use single bracket under upper retaining bolt head to prevent pin failure. · GT3 Mazda 12A Peripheral Port added, 2300 cc, 2300 lbs, SIR head, 2 valves per cylinder. · TA2 Gurney flap wording clarified: replace 'wicker bill' and 'wicker' with 'Gurney flap' throughout wing specifications. · STO rear wing rules clarify that wicker is called Gurney flap in two places; no performance change. · GT Gurney flap wording clarified: wickerbill and tab terminology replaced with Gurney flap throughout sections 9.1.2.F.7.b. · GT3 4v SIR fuel induction increases from 31 to 32 mm across 20 engine variants. · GT3 and STU add Borg-Warner EFR6258 turbocharger to approved turbo lists. · GT3 Nissan KA24E loses 32mm choke option at 2280 lbs for 2011-2012. · GT3 Mazda MZR L5-VE fuel induction changed to 31mm SIR, weight increased to 2195 lbs, direct injection prohibited. · GT1, GT2, GT3, GTL, GTX may use bonded-glass factory windshields without clips or straps if attached per original specifications. · GTX Misc. adds Factory Five Type 65 Coupe R Ford 302/351 and 5.0/5.2L NA at 2600 lbs, plus Ferrari 458/488 Challenge, Ford FP350S, Chevrolet C6, Lamborghini Super Trofeo. · GT3 Mazda 13B Bridgeport restrictor reduced from 44mm to 42mm. · GT3 Alfa 4C turbocharged 1742cc classified with 33mm restrictor, minimum weight 2325 lbs. · GT3 Mazda MZR/L5-VE gets unrestricted fuel induction, drops to 1950 lbs minimum weight, limited to GT2 prep. · GT3 adds Honda K20C1 turbocharged engine, 1928 cc, 33 mm restrictor, 2350 lbs minimum. · GT3 wing end plates change from 11.00 × 4.00 inch rectangle to maximum 64 square inches. · FE minimum weight rises to 1270 lbs; FE2 minimum weight rises to 1270 lbs; new spring options added; tire warmers prohibited. · GT3 Nissan adds SR16VE engine, 1596 cc DOHC, 1690 lbs, unrestricted fuel induction.showhide
  • SM Radiator E&O Clarifications #29294wordingwordingSM allows aftermarket radiators in original location with stock OEM cooling fan, and permits 1990-1997 cars to install upper radiator seal NA75-50-OK7A.
  • FE2 FE/FE2 Oil Cooler #29293wordingwordingFE2 oil cooler rule clarified: Setrab 50-625-7612 or any cooler with max core 13 inches wide by 6.5 inches high allowed.
  • GT3 GT Category Wording #29193wordingaddedGT1/GT2/GT3/GTL/GTX turbocharging and supercharging now permitted if listed on spec line.
  • SM Modifications to prevent failures of Rear Brake Caliper Pin #28953suspension & brakessuspension & brakesSM rear brake caliper may use single bracket under upper retaining bolt head to prevent pin failure.
  • GT3 Request to add Mazda 12A Peripheral Port to GT3 rule set #28842cars addedaddedGT3 Mazda 12A Peripheral Port added, 2300 cc, 2300 lbs, SIR head, 2 valves per cylinder.
  • GT3 TA2 Gurney flap wicker clarification #28874wordingwordingTA2 Gurney flap wording clarified: replace 'wicker bill' and 'wicker' with 'Gurney flap' throughout wing specifications.
  • GT3 STO Gurney flap wicker clarification #28883wordingwordingSTO rear wing rules clarify that wicker is called Gurney flap in two places; no performance change.
  • GT3 GT Gurney flap wicker clarification #28909wordingwordingGT Gurney flap wording clarified: wickerbill and tab terminology replaced with Gurney flap throughout sections 9.1.2.F.7.b.
  • GT3 GT3 4v SIR size increase. #28931inductionfaster · inductionGT3 4v SIR fuel induction increases from 31 to 32 mm across 20 engine variants.
  • GT3 Request for Addition to GT3 Approved Turbo List #27576cars addedaddedGT3 and STU add Borg-Warner EFR6258 turbocharger to approved turbo lists.
  • GT3 Request Nissan KA24E specifications #28808inductionremoved · inductionGT3 Nissan KA24E loses 32mm choke option at 2280 lbs for 2011-2012.
  • GT3 Error Regarding Mazda Engine Listing #28119induction +245 lbsslower · inductionGT3 Mazda MZR L5-VE fuel induction changed to 31mm SIR, weight increased to 2195 lbs, direct injection prohibited.
  • GT3 Windshield Clips #27323otheraddedGT1, GT2, GT3, GTL, GTX may use bonded-glass factory windshields without clips or straps if attached per original specifications.
  • GT3 Request Factory Five Daytona coupe classification #26308cars addedaddedGTX Misc. adds Factory Five Type 65 Coupe R Ford 302/351 and 5.0/5.2L NA at 2600 lbs, plus Ferrari 458/488 Challenge, Ford FP350S, Chevrolet C6, Lamborghini Super Trofeo.
  • GT3 Request restrictor size change request #26958inductionslower · inductionGT3 Mazda 13B Bridgeport restrictor reduced from 44mm to 42mm.
  • GT3 Request to Classify Alfa Romeo 4C #27322cars addedaddedGT3 Alfa 4C turbocharged 1742cc classified with 33mm restrictor, minimum weight 2325 lbs.
  • GT3 Request for Mazda 2.5l MZR/L5-VE #27570engine -245 lbsfaster · engineGT3 Mazda MZR/L5-VE gets unrestricted fuel induction, drops to 1950 lbs minimum weight, limited to GT2 prep.
  • GT3 GT3 turbo engines add Honda #28033cars addedaddedGT3 adds Honda K20C1 turbocharged engine, 1928 cc, 33 mm restrictor, 2350 lbs minimum.
  • GT3 GT3 wing end plate #28035otherunclearGT3 wing end plates change from 11.00 × 4.00 inch rectangle to maximum 64 square inches.
  • FE2 FE / FE2 Update Rules #27624weightslower · weightFE minimum weight rises to 1270 lbs; FE2 minimum weight rises to 1270 lbs; new spring options added; tire warmers prohibited.
  • GT3 Request to Add SR16VE to GT-3 Spec Lines #27357cars addedaddedGT3 Nissan adds SR16VE engine, 1596 cc DOHC, 1690 lbs, unrestricted fuel induction.
Virginia International Raceway Runoffs 20192019-10-051:58.194Michael Lewis · fastest of 17 · top 5 within 2.2s1:59.045Tony Ave · fastest of 16 · top 5 within 1.7s149.6Jeff Dernehl1:55.124Bryce Cornet · fastest of 8 · top 5 within 2.3s2:15.816Bryce Cornet · fastest of 8 · top 5 within 4.9s135.7Bryce Cornet+16.771squal -3.070s114.1%qual 97.4%2:14.552Todd Buras · fastest of 60 · top 5 within 0.2s2:16.459Elivan Goulart · fastest of 56 · top 5 within 0.4s119.8Jim Drago+17.414squal +16.358s114.6%qual 113.8%1:51.062Liam Snyder · fastest of 20 · top 5 within 1.3s1:52.154Liam Snyder · fastest of 19 · top 5 within 0.7s142.6Robert Vanman-6.891squal -7.132s94.2%qual 94.0%
12 rule changes (GT3: 8, SM: 4)2 cars added · 1 engine · 1 induction · 1 weight · 3 wording · 4 other · GT3 Mazda 12A Bridgeport gains optional 42mm choke at 2010 lbs minimum weight. · GTX tube frame cars now allowed fuel injection with maximum 90mm throttle body. · GTX adds Ligier JS2 R classification with restrictor and minimum weight. · GT3 Mazda 13B and Renesis engines completely respecified with new induction types and weights ranging 2080–2350 lbs. · GT1 and GT2/3/Lite remove ride height ground clearance rules; cars may now touch ground when tires deflate. · GT3 13B Street Port removed; 13B Peripheral Port weight raised to 2400 lbs; 13B Bridge Port weight raised to 2400 lbs; Renesis Street Port removed; Renesis Peripheral Port weight raised to 2450 lbs; Renesis Bridge Port weight raised to 245… · GT3 adds Mitsubishi 4G69 SOHC engine, 2378 cc, 2195 lbs, 31mm SIR. · SM fuel pump and filter now permitted as Mazda or OEM equivalent part. · SM allows factory Mazda ECU and injector harnesses (P/N 0000-10-020E-99, 0000-10-080D-99) on 1999–2000 model year cars, unmodified. · SM electrical rules reorganized and clarified; alternator now externally regulated only by OEM ECU or master kill switch; harness repair by splicing permitted. · SM tire tread protrusion language removed from GCR 9.1.7.C.5. · GTX FIA GT3: Audi R8 now 40 mm restrictor and 2900 lbs; BMW Z4 now 70 mm restrictor and 2800 lbs; Ferrari 488 now 35 mm restrictor, TIR, and 3025 lbs.showhide
  • GT3 Requesting Increase in Choke Diameter for Mazda 12A Bridgeport #27043inductionadded · inductionGT3 Mazda 12A Bridgeport gains optional 42mm choke at 2010 lbs minimum weight.
  • GT3 Request GTX Fuel injection for previous GT-1 tube frame cars #26141engineadded · engineGTX tube frame cars now allowed fuel injection with maximum 90mm throttle body.
  • GT3 Request to Classify Ligier JS2 R #26535cars addedaddedGTX adds Ligier JS2 R classification with restrictor and minimum weight.
  • GT3 26076 revised Spec line chart #26528otherunclearGT3 Mazda 13B and Renesis engines completely respecified with new induction types and weights ranging 2080–2350 lbs.
  • GT3 Request Ride Height Clarification #26600wordingfasterGT1 and GT2/3/Lite remove ride height ground clearance rules; cars may now touch ground when tires deflate.
  • GT3 Request clarification on bridge porting for rotary #26076weightslower · weightGT3 13B Street Port removed; 13B Peripheral Port weight raised to 2400 lbs; 13B Bridge Port weight raised to 2400 lbs; Renesis Street Port removed; Renesis Peripheral Port weight raised to 2450 lbs; Renesis Bridge Port weight raised to 245…
  • GT3 Request to add 4G69 Mitsubishi #26154cars addedaddedGT3 adds Mitsubishi 4G69 SOHC engine, 2378 cc, 2195 lbs, 31mm SIR.
  • SM Request to allow aftermarket fuel filters. #26370otheraddedSM fuel pump and filter now permitted as Mazda or OEM equivalent part.
  • SM Request 99-00 replacement Wire harnesses #25602otheraddedSM allows factory Mazda ECU and injector harnesses (P/N 0000-10-020E-99, 0000-10-080D-99) on 1999–2000 model year cars, unmodified.
  • SM Organize and Clarify 9.1.7.C.1.o. #25913wordingwordingSM electrical rules reorganized and clarified; alternator now externally regulated only by OEM ECU or master kill switch; harness repair by splicing permitted.
  • SM Strike Tire Tread Language #26123wordingremovedSM tire tread protrusion language removed from GCR 9.1.7.C.5.
  • GT3 GTX Homologation table update #26034otherunclearGTX FIA GT3: Audi R8 now 40 mm restrictor and 2900 lbs; BMW Z4 now 70 mm restrictor and 2800 lbs; Ferrari 488 now 35 mm restrictor, TIR, and 3025 lbs.
Sonoma Raceway Runoffs 20182018-10-101:40.947Michael Lewis · fastest of 10 · top 5 within 3.8s1:42.634Michael Lewis · fastest of 8 · top 5 within 4.4s115.7Collin Jackson1:37.598Bryce Cornet · fastest of 13 · top 5 within 0.9s1:37.909Bryce Cornet · fastest of 12 · top 5 within 1.3s124.1Melvin David Kemper Jr-4.725squal -3.349s95.4%qual 96.7%1:54.355Ken Sutherland · fastest of 48 · top 5 within 0.7s1:55.278Michael Carter · fastest of 48 · top 5 within 0.3s102.2Danny Steyn+12.644squal +13.408s112.3%qual 113.3%1:35.040Flinn Lazier · fastest of 9 · top 5 within 1.5s1:35.563Flinn Lazier · fastest of 9 · top 5 within 1.7s126.8Scott Rettich-7.071squal -5.907s93.1%qual 94.1%
No rule changes on record between these events
Indianapolis Motor Speedway Runoffs 20172017-09-251:44.579Collin Jackson · fastest of 17 · top 5 within 5.0s1:46.330Collin Jackson · fastest of 15 · top 5 within 3.1s1:41.231Jarret Voorhies · fastest of 16 · top 5 within 1.7s1:41.146Jarret Voorhies · fastest of 16 · top 5 within 1.2s-5.184squal -3.348s95.1%qual 96.8%1:58.306Chris Haldeman · fastest of 86 · top 5 within 0.5s1:59.100Michael Gagliardo · fastest of 83 · top 5 within 0.6s+12.770squal +13.727s112.0%qual 113.1%
No rule changes on record between these events
Mid-Ohio Sports Car Course Runoffs 20162016-09-191:30.797Gary Bockman · fastest of 15 · top 5 within 2.0s1:31.107Joe Kristensen · fastest of 14 · top 5 within 2.5s1:26.043Jacob Loomis · fastest of 8 · top 5 within 3.1s1:27.922Jacob Loomis · fastest of 8 · top 5 within 2.7s-3.185squal -4.754s96.5%qual 94.8%1:40.514Justin Hille · fastest of 45 · top 5 within 0.3s1:40.764Michael Carter · fastest of 44 · top 5 within 0.3s+9.657squal +9.717s110.6%qual 110.7%
No rule changes on record between these events
Daytona International Speedway Runoffs 20152015-09-212:01.736Joe Kristensen · fastest of 11 · top 5 within 3.0s2:03.617Joe Kristensen · fastest of 10 · top 5 within 1.8s1:57.804Joseph Burton-Harris · fastest of 10 · top 5 within 2.3s1:58.029Joseph Burton-Harris · fastest of 10 · top 5 within 1.7s-5.588squal -3.932s95.5%qual 96.8%2:18.661Andrew Carbonell · fastest of 62 · top 5 within 0.6s2:24.067Todd Lamb · fastest of 59 · top 5 within 0.8s+20.450squal +16.925s116.5%qual 113.9%

By track

TrackEventsTypical % of GT3BestLatest
Road America4100.0%2 of 4 with GT3100.0%Runoffs 2020100.0%Runoffs 2024
Virginia International Raceway3100.0%100.0%Runoffs 2019100.0%Runoffs 2023
Indianapolis Motor Speedway2100.0%100.0%Runoffs 2017100.0%Runoffs 2021
Daytona International Speedway1100.0%100.0%Runoffs 2015100.0%Runoffs 2015
Mid-Ohio Sports Car Course1100.0%100.0%Runoffs 2016100.0%Runoffs 2016
Sonoma Raceway1100.0%100.0%Runoffs 2018100.0%Runoffs 2018
About this data
Every event the class ran, at any track, oldest to newest on the chart and newest first in the table. Each point is the class's best lap as a share of GT3's best on the same day: the weather, the track and its configuration cancel out, so one figure compares across tracks and years where lap times cannot. It still moves when the yardstick's own balance changes or its field thins, and an event the yardstick did not run has no point. A best from fewer than three cars is greyed. The rule changes that took effect between two events are folded between their rows.