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BoP Lab / Classes / P2

P2 vs SM vs GTL vs STL pace at every track

Lap times across years say as much about the weather as the class. % of P2 is each class's best lap as a share of P2'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: P2 1:20.188 Jeff Shafer, Runoffs 2016 qualifying · SM 1:40.514 Justin Hille, Runoffs 2016 qualifying · GTL 1:35.377 Wilson Wright, Runoffs 2016 qualifying · STL 1:35.439 John Schmitt, Runoffs 2016 qualifying

1:402:002:202:4037 rule changes between Runoffs 2018 and Runoffs 201937 ▾36 rule changes between Runoffs 2019 and Runoffs 202036 ▾32 rule changes between Runoffs 2020 and Runoffs 202132 ▾19 rule changes between Runoffs 2021 and Runoffs 202219 ▾18 rule changes between Runoffs 2022 and Runoffs 202318 ▾29 rule changes between Runoffs 2023 and Runoffs 202429 ▾11 rule changes between Runoffs 2024 and Runoffs 202511 ▾7 rule changes between Runoffs 2025 and Runoffs 20267 ▾P2 race best at Runoffs 2015: 1:52.355 (Jeff Shafer)Off the chart: P2 race best at Runoffs 2016: 1:20.904 (Jeff Shafer)P2 race best at Runoffs 2017: 1:32.481 (Jeff Shafer)P2 race best at Runoffs 2018: 1:32.071 (Chuck Bona)P2 race best at Runoffs 2019: 1:50.258 (Greg Gyann)P2 race best at Runoffs 2020: 2:09.793 (Robert Iversen)P2 race best at Runoffs 2021: 1:35.322 (Tim Day Jr)P2 race best at Runoffs 2022: 2:15.834 (Greg Gyann)P2 race best at Runoffs 2023: 1:48.829 (Lucian Pancea)P2 race best at Runoffs 2024: 2:08.322 (Bart Wolf)P2 race best at Runoffs 2026: 2:09.441 (Mike Reupert)P2 qualifying best at Runoffs 2015: 1:51.825 (Chris Farrell)Off the chart: P2 qualifying best at Runoffs 2016: 1:20.188 (Jeff Shafer)P2 qualifying best at Runoffs 2017: 1:31.826 (Jeff Shafer)P2 qualifying best at Runoffs 2018: 1:28.784 (Tim Day Jr)P2 qualifying best at Runoffs 2019: 1:49.111 (Robert Iversen)P2 qualifying best at Runoffs 2020: 2:08.514 (Robert Iversen)P2 qualifying best at Runoffs 2021: 1:33.235 (Tim Day Jr)P2 qualifying best at Runoffs 2022: 1:47.566 (Tim Day Jr)P2 qualifying best at Runoffs 2023: 1:48.590 (Greg Gyann)P2 qualifying best at Runoffs 2024: 2:07.405 (Bart Wolf)P2 qualifying best at Runoffs 2026: 2:10.606 (Greg Gyann)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)GTL race best at Runoffs 2015: 2:13.564 (Jim Dentici)GTL race best at Runoffs 2016: 1:35.912 (Kyle Disque)GTL race best at Runoffs 2017: 1:52.068 (Christopher Bovis)GTL race best at Runoffs 2018: 1:49.458 (Troy Ermish)GTL race best at Runoffs 2019: 2:07.837 (Bill Ball)GTL race best at Runoffs 2020: 2:31.601 (Peter Shadowen)GTL race best at Runoffs 2021: 1:51.952 (Scott Twomey)GTL race best at Runoffs 2022: 2:21.180 (Michael Lewis)GTL race best at Runoffs 2023: 2:11.277 (Graham Fuller)GTL race best at Runoffs 2024: 2:30.844 (Chris Bovis)GTL qualifying best at Runoffs 2015: 2:11.387 (Jim Dentici)GTL qualifying best at Runoffs 2016: 1:35.377 (Wilson Wright)GTL qualifying best at Runoffs 2017: 1:50.331 (Christopher Bovis)GTL qualifying best at Runoffs 2018: 1:47.885 (Troy Ermish)GTL qualifying best at Runoffs 2019: 2:06.997 (Peter Shadowen)GTL qualifying best at Runoffs 2020: 2:31.943 (Chris Bovis)GTL qualifying best at Runoffs 2021: 1:51.819 (Christopher Bovis)GTL qualifying best at Runoffs 2022: 2:07.789 (Peter Shadowen)GTL qualifying best at Runoffs 2023: 2:09.564 (Peter Shadowen)GTL qualifying best at Runoffs 2024: 2:30.858 (Peter Shadowen)STL race best at Runoffs 2015: 2:10.269 (Kevin Boehm)STL race best at Runoffs 2016: 1:36.625 (Kevin Boehm)STL race best at Runoffs 2017: 1:52.589 (Eric Kutil)STL race best at Runoffs 2018: 1:49.754 (Danny Steyn)STL race best at Runoffs 2019: 2:07.273 (Cliff Ira)STL race best at Runoffs 2020: 2:32.115 (Joe Moser)STL race best at Runoffs 2021: 2:02.711 (Joe Moser)STL race best at Runoffs 2022: 2:07.832 (Danny Steyn)STL race best at Runoffs 2023: 2:06.682 (Joe Moser)STL race best at Runoffs 2024: 2:30.245 (Joe Moser)STL race best at Runoffs 2025: 2:32.127 (Jose Osiris Pena)STL race best at Runoffs 2026: 2:30.657 (Danny Steyn)STL qualifying best at Runoffs 2015: 2:09.672 (Kevin Boehm)STL qualifying best at Runoffs 2016: 1:35.439 (John Schmitt)STL qualifying best at Runoffs 2017: 1:52.647 (Adam Roberts)STL qualifying best at Runoffs 2018: 1:49.138 (Danny Steyn)STL qualifying best at Runoffs 2019: 2:07.203 (Danny Steyn)STL qualifying best at Runoffs 2020: 2:31.420 (Danny Steyn)STL qualifying best at Runoffs 2021: 1:51.665 (Danny Steyn)STL qualifying best at Runoffs 2022: 2:05.474 (Danny Steyn)STL qualifying best at Runoffs 2023: 2:05.779 (Danny Steyn)STL qualifying best at Runoffs 2024: 2:30.063 (Joe Moser)STL qualifying best at Runoffs 2025: 2:32.065 (Jose Osiris Pena)STL qualifying best at Runoffs 2026: 2:30.537 (Derek Ketchie)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
P2SMGTLSTLsolid race · dashed qualifying · slower is lower
100%110%120%130%37 rule changes between Runoffs 2018 and Runoffs 201937 ▾36 rule changes between Runoffs 2019 and Runoffs 202036 ▾32 rule changes between Runoffs 2020 and Runoffs 202132 ▾19 rule changes between Runoffs 2021 and Runoffs 202219 ▾18 rule changes between Runoffs 2022 and Runoffs 202318 ▾29 rule changes between Runoffs 2023 and Runoffs 202429 ▾11 rule changes between Runoffs 2024 and Runoffs 202511 ▾7 rule changes between Runoffs 2025 and Runoffs 20267 ▾P2 race best at Runoffs 2015: 100.0% of P2's (Jeff Shafer)P2 race best at Runoffs 2016: 100.0% of P2's (Jeff Shafer)P2 race best at Runoffs 2017: 100.0% of P2's (Jeff Shafer)P2 race best at Runoffs 2018: 100.0% of P2's (Chuck Bona)P2 race best at Runoffs 2019: 100.0% of P2's (Greg Gyann)P2 race best at Runoffs 2020: 100.0% of P2's (Robert Iversen)P2 race best at Runoffs 2021: 100.0% of P2's (Tim Day Jr)P2 race best at Runoffs 2022: 100.0% of P2's (Greg Gyann)P2 race best at Runoffs 2023: 100.0% of P2's (Lucian Pancea)P2 race best at Runoffs 2024: 100.0% of P2's (Bart Wolf)P2 race best at Runoffs 2026: 100.0% of P2's (Mike Reupert)P2 qualifying best at Runoffs 2015: 100.0% of P2's (Chris Farrell)P2 qualifying best at Runoffs 2016: 100.0% of P2's (Jeff Shafer)P2 qualifying best at Runoffs 2017: 100.0% of P2's (Jeff Shafer)P2 qualifying best at Runoffs 2018: 100.0% of P2's (Tim Day Jr)P2 qualifying best at Runoffs 2019: 100.0% of P2's (Robert Iversen)P2 qualifying best at Runoffs 2020: 100.0% of P2's (Robert Iversen)P2 qualifying best at Runoffs 2021: 100.0% of P2's (Tim Day Jr)P2 qualifying best at Runoffs 2022: 100.0% of P2's (Tim Day Jr)P2 qualifying best at Runoffs 2023: 100.0% of P2's (Greg Gyann)P2 qualifying best at Runoffs 2024: 100.0% of P2's (Bart Wolf)P2 qualifying best at Runoffs 2026: 100.0% of P2's (Greg Gyann)SM race best at Runoffs 2015: 128.2% of P2's (Todd Lamb)SM race best at Runoffs 2016: 124.5% of P2's (Michael Carter)SM race best at Runoffs 2017: 128.8% of P2's (Michael Gagliardo)SM race best at Runoffs 2018: 125.2% of P2's (Michael Carter)SM race best at Runoffs 2019: 123.8% of P2's (Elivan Goulart)SM race best at Runoffs 2020: 126.2% of P2's (Preston Pardus)SM race best at Runoffs 2021: 124.7% of P2's (Brian Henderson)SM race best at Runoffs 2022: 102.4% of P2's (Travis Wiley)SM race best at Runoffs 2023: 125.2% of P2's (Julian DaCosta)SM race best at Runoffs 2024: 125.8% of P2's (Brett Kowalski)SM race best at Runoffs 2026: 125.7% of P2's (Francisco Barroso)SM qualifying best at Runoffs 2015: 124.0% of P2's (Andrew Carbonell)SM qualifying best at Runoffs 2016: 125.3% of P2's (Justin Hille)SM qualifying best at Runoffs 2017: 128.8% of P2's (Chris Haldeman)SM qualifying best at Runoffs 2018: 128.8% of P2's (Ken Sutherland)SM qualifying best at Runoffs 2019: 123.3% of P2's (Todd Buras)SM qualifying best at Runoffs 2020: 126.2% of P2's (Kyle Greenhill)SM qualifying best at Runoffs 2021: 126.2% of P2's (Brian Henderson)SM qualifying best at Runoffs 2022: 125.2% of P2's (Danny Steyn)SM qualifying best at Runoffs 2023: 124.3% of P2's (Danny Steyn)SM qualifying best at Runoffs 2024: 126.5% of P2's (Ethan Goulart)SM qualifying best at Runoffs 2026: 124.2% of P2's (Brett Kowalski)GTL race best at Runoffs 2015: 118.9% of P2's (Jim Dentici)GTL race best at Runoffs 2016: 118.6% of P2's (Kyle Disque)GTL race best at Runoffs 2017: 121.2% of P2's (Christopher Bovis)GTL race best at Runoffs 2018: 118.9% of P2's (Troy Ermish)GTL race best at Runoffs 2019: 115.9% of P2's (Bill Ball)GTL race best at Runoffs 2020: 116.8% of P2's (Peter Shadowen)GTL race best at Runoffs 2021: 117.4% of P2's (Scott Twomey)GTL race best at Runoffs 2022: 103.9% of P2's (Michael Lewis)GTL race best at Runoffs 2023: 120.6% of P2's (Graham Fuller)GTL race best at Runoffs 2024: 117.6% of P2's (Chris Bovis)GTL qualifying best at Runoffs 2015: 117.5% of P2's (Jim Dentici)GTL qualifying best at Runoffs 2016: 118.9% of P2's (Wilson Wright)GTL qualifying best at Runoffs 2017: 120.2% of P2's (Christopher Bovis)GTL qualifying best at Runoffs 2018: 121.5% of P2's (Troy Ermish)GTL qualifying best at Runoffs 2019: 116.4% of P2's (Peter Shadowen)GTL qualifying best at Runoffs 2020: 118.2% of P2's (Chris Bovis)GTL qualifying best at Runoffs 2021: 119.9% of P2's (Christopher Bovis)GTL qualifying best at Runoffs 2022: 118.8% of P2's (Peter Shadowen)GTL qualifying best at Runoffs 2023: 119.3% of P2's (Peter Shadowen)GTL qualifying best at Runoffs 2024: 118.4% of P2's (Peter Shadowen)STL race best at Runoffs 2015: 115.9% of P2's (Kevin Boehm)STL race best at Runoffs 2016: 119.4% of P2's (Kevin Boehm)STL race best at Runoffs 2017: 121.7% of P2's (Eric Kutil)STL race best at Runoffs 2018: 119.2% of P2's (Danny Steyn)STL race best at Runoffs 2019: 115.4% of P2's (Cliff Ira)STL race best at Runoffs 2020: 117.2% of P2's (Joe Moser)STL race best at Runoffs 2021: 128.7% of P2's (Joe Moser)Off the chart: STL race best at Runoffs 2022: 94.1% of P2's (Danny Steyn)STL race best at Runoffs 2023: 116.4% of P2's (Joe Moser)STL race best at Runoffs 2024: 117.1% of P2's (Joe Moser)STL race best at Runoffs 2026: 116.4% of P2's (Danny Steyn)STL qualifying best at Runoffs 2015: 116.0% of P2's (Kevin Boehm)STL qualifying best at Runoffs 2016: 119.0% of P2's (John Schmitt)STL qualifying best at Runoffs 2017: 122.7% of P2's (Adam Roberts)STL qualifying best at Runoffs 2018: 122.9% of P2's (Danny Steyn)STL qualifying best at Runoffs 2019: 116.6% of P2's (Danny Steyn)STL qualifying best at Runoffs 2020: 117.8% of P2's (Danny Steyn)STL qualifying best at Runoffs 2021: 119.8% of P2's (Danny Steyn)STL qualifying best at Runoffs 2022: 116.6% of P2's (Danny Steyn)STL qualifying best at Runoffs 2023: 115.8% of P2's (Danny Steyn)STL qualifying best at Runoffs 2024: 117.8% of P2's (Joe Moser)STL qualifying best at Runoffs 2026: 115.3% of P2's (Derek Ketchie)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
P2SMGTLSTLsolid race · dashed qualifying · each class's best lap as a share of P2's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker
EventP2SMGTLSTL
Qual bestRace bestTrapQual bestRace bestTrapvs P2% of P2Qual bestRace bestTrapvs P2% of P2Qual bestRace bestTrapvs P2% of P2
Road America Runoffs 20262026-09-282:10.606Greg Gyann · fastest of 11 · top 5 within 5.3s+3.201s (+2.51%)2:09.441Mike Reupert · fastest of 11 · top 5 within 4.2s+1.119s (+0.87%)155.0Matt Strand+2.4 mph (+1.6%)2:42.173Brett 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%)+33.284squal +31.567s125.7%qual 124.2%2:30.537Derek Ketchie · fastest of 16 · top 5 within 2.9s-1.528s (-1.00%)2:30.657Danny Steyn · fastest of 16 · top 5 within 0.6s-1.470s (-0.97%)134.8Mike Taylor+2.6 mph (+2.0%)+21.216squal +19.931s116.4%qual 115.3%
7 rule changes (SM: 2, GTL: 1, STL: 4)3 cars added · 1 weight · 2 wording · 1 other · SM/SMX Mazda rear toe link part number revised from 0000-04-5361426 to 0000-04-5361. · STL removes Mazda MX-5 Cup entirely; renames Spec MX5 Challenge to Spec MX5; renames Global Cup to MX-5 Cup (16-18); removes Global Cup (2019). · STL, STU weight calculation procedure clarified: positive percentages added first, negative subtracted second, then fixed weights applied. · SM/SMX part number 0000-10-6900 replaced with 0000-06-5016-KT in GCR 9.1.7.C.1.j.1.c. · STL adds Mazda BP 1.6, 1600cc, minimum weight 2160 lbs. · GT3U class removed from GCR; GT3U cars now compete in STU. · STL minimum weights increase across all engine sizes, 1300cc to 1850cc up to 195–250 lbs.showhide
  • SM Rear Toe Link #40271wordingwordingSM/SMX Mazda rear toe link part number revised from 0000-04-5361426 to 0000-04-5361.
  • STL Spec Line Clean Up #40344cars addedremoved · cars addedSTL removes Mazda MX-5 Cup entirely; renames Spec MX5 Challenge to Spec MX5; renames Global Cup to MX-5 Cup (16-18); removes Global Cup (2019).
  • STL Calculating Weight #40224wordingwordingSTL, STU weight calculation procedure clarified: positive percentages added first, negative subtracted second, then fixed weights applied.
  • 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.
  • STL Classifications #39885cars addedaddedSTL adds Mazda BP 1.6, 1600cc, minimum weight 2160 lbs.
  • GTL Remove GT3U from GCR as it is now in STU #39862cars addedremoved · cars addedGT3U class removed from GCR; GT3U cars now compete in STU.
  • STL Weight adjustment for STL #39579weightslower · weightSTL minimum weights increase across all engine sizes, 1300cc to 1850cc up to 195–250 lbs.
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%)2:32.065Jose Osiris Pena · fastest of 14 · top 5 within 3.4s+2.002s (+1.33%)2:32.127Jose Osiris Pena · fastest of 13 · top 5 within 2.4s+1.882s (+1.25%)132.2Jon Sewell-2.1 mph (-1.5%)
11 rule changes (P2: 1, SM: 4, GTL: 3, STL: 3)2 engine · 2 weight · 1 cars added · 5 wording · 1 other · Lotus Evora GT4 minimum weight drops to 2700 lbs; Elise Cup R to 2250 lbs; Elise SC and Exige SC to 2450–2550 lbs. · 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. · 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. · STL Mazda MX5 Challenge minimum weight now references GCR 9.1.7.1; mandatory component spec list removed, alternative tires only allowed. · TA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof height limit. · P2 2000 cc Pinto engine car minimum weight set to 1335 lbs. · 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. · STL STU Mazda Miata alternate front hubs Mazda Motorsports Development Part #0000-04-5HUB-S1 approved. · GTL Toyota G16E-GTS removes direct injection prohibition, allowing direct injection engines. · GTL L16 limited prep gains 32mm choke option at 1910 lbs, compression capped 12.0:1, valve lift .450 max.showhide
  • STL Lotus Weight Reduction #38772weight -50 lbsfaster · weightLotus Evora GT4 minimum weight drops to 2700 lbs; Elise Cup R to 2250 lbs; Elise SC and Exige SC to 2450–2550 lbs.
  • 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.
  • 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.
  • STL E&O: SMX Allowance in STL #37945wordingunclearSTL Mazda MX5 Challenge minimum weight now references GCR 9.1.7.1; mandatory component spec list removed, alternative tires only allowed.
  • GTL Correct language regarding OEM Areo Devices #37137wordingwordingTA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof height limit.
  • P2 2000 cc Pinto Engine Car Weight #37187weightslower · weightP2 2000 cc Pinto engine car minimum weight set to 1335 lbs.
  • 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.
  • STL Request to Remove Miata Hubs from General category #37138cars addedaddedSTL STU Mazda Miata alternate front hubs Mazda Motorsports Development Part #0000-04-5HUB-S1 approved.
  • GTL G16E-GTS Fuel Injection Spec Line Change #36588engineadded · engineGTL Toyota G16E-GTS removes direct injection prohibition, allowing direct injection engines.
  • GTL GTL Alternate Weight and Choke Option for L16 engine #36653engineadded · engineGTL L16 limited prep gains 32mm choke option at 1910 lbs, compression capped 12.0:1, valve lift .450 max.
Road America Runoffs 20242024-10-012:07.405Bart Wolf · fastest of 14 · top 5 within 3.0s-1.109s (-0.86%)2:08.322Bart Wolf · fastest of 13 · top 5 within 0.6s-1.471s (-1.13%)152.5Lucian Pancea-0.6 mph (-0.4%)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%)+33.164squal +33.701s125.8%qual 126.5%2:30.858Peter Shadowen · fastest of 14 · top 5 within 4.4s-1.085s (-0.71%)2:30.844Chris Bovis · fastest of 13 · top 5 within 3.7s-0.757s (-0.50%)133.3Peter Shadowen+1.8 mph (+1.4%)+22.522squal +23.453s117.6%qual 118.4%2:30.063Joe Moser · fastest of 18 · top 5 within 3.7s-1.357s (-0.90%)2:30.245Joe Moser · fastest of 16 · top 5 within 4.2s-1.870s (-1.23%)134.3Joe Moser+1.3 mph (+1.0%)+21.923squal +22.658s117.1%qual 117.8%
29 rule changes (P2: 5, SM: 4, GTL: 16, STL: 4)7 engine · 5 cars added · 4 weight · 2 aero · 1 induction · 8 wording · 2 other · GTL adds Toyota GR86 2021–2023, 2dr RWD, 101.3 in wheelbase. · GTL adds Spec Miata 1990–2005 with legal Spec Miata engine and intake system. · GTL adds Mazda MX5 RF 2017- model with 91.0 in wheelbase. · 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. · GTL added to GT3 choke option line in GCR 9.1.2.E.13.n. · GT2-ST Acura NSX minimum weight rises to 3000 lbs, restrictor increases to 45mm TIR. · GTL Datsun 510 Limited Prep fuel induction increased to 34 mm chokes, minimum weight rises to 2000 lbs. · P2 Spec Line E engine notes clarify oil system, ECU, and exhaust remain unrestricted; wording only. · P2 FIA Group CN notes clarify V de V European Proto Endurance Challenge bodywork, rear diffuser, wing, wheels, assisted shifting allowed; regulations link provided. · 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. · GT2 Nissan and GT3 Mazda, Mitsubishi 4G93, Nissan QR25DE/DD, QE25DE/DD now permit Direct Injection per 9.1.2.F.7.5.E. · STL and STU now permit electric power steering pumps, OEM electric-assisted steering, or column-mounted electric steering assist systems. · STL normally aspirated minimum weights reduced: 1900cc to 2540 lbs, 1950cc to 2583 lbs, 2000cc to 2625 lbs; short-wheelbase FWD adds 1.25%; Honda B16/B17/B18C1 throttle to 51mm, B18C Type R and Mazda MZR to 50mm. · STL Mazda 12A: 5th and 6th intake port actuators and valves may no longer be removed or disabled. · GTL 12A rotary engines may machine and use 13B housing to O.E. 12A spec across all port types. · GTL Toyota DR86 2021–2024 added to class. · GTL BMW Mini model years changed to 2002-2013. · P2 AMAC and related cars: clarified B.1 modified engine range to 2008 and older stock engines only, with 38mm restrictor and 1025 lbs minimum weight. · P2 Suzuki GSX-R1000 engine: 2007–2008 crankcase 11300-21860 may be replaced with 2016–2019 GSX-S1000 part 11301-04840. · STL 79-85 RX7 12A now allows auto-type 2 bbl carburetor with 42mm choke on dual-y manifold, not just stock Nikki. · GTL small unrestricted engines under 1399cc lose 38–79 lbs across Alfa, AMC, Triumph, Mini, Sprite, Fiat, Ford, Honda, Mazda, Nissan, Subaru, Toyota, Volkswagen. · GTL Honda Fit 2009-13 2-door FWD added with 99.0 in wheelbase, alternate 94.0 and 97.0 in. · 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. · P2 Table 1 engine date ranges clarified: Stock Engine replaced with specific marques Suzuki, Yamaha, Honda, BMW for 2009-newer and 2008-older rows. · GTL Nissan Sentra/200SX A 1400 minimum weight reduced to 1800 lbs.showhide
  • GTL Request to Include Toyota GR86 in GTL #36324cars addedaddedGTL adds Toyota GR86 2021–2023, 2dr RWD, 101.3 in wheelbase.
  • GTL Inclusion of Modified Spec Miata for GTL competition #36325cars addedaddedGTL adds Spec Miata 1990–2005 with legal Spec Miata engine and intake system.
  • GTL Include Mazda MX5 RF 2017- in GTL #36428cars addedaddedGTL adds Mazda MX5 RF 2017- model with 91.0 in wheelbase.
  • 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.
  • GTL Add GTL to GT3 choke option line. #36236otheraddedGTL added to GT3 choke option line in GCR 9.1.2.E.13.n.
  • GTL Request for Spec Line 1010 Reconsideration #35009weight +300 lbsslower · weightGT2-ST Acura NSX minimum weight rises to 3000 lbs, restrictor increases to 45mm TIR.
  • GTL Allow 34 mm chokes for the Datsun 510 #35661induction +50 lbsfaster · inductionGTL Datsun 510 Limited Prep fuel induction increased to 34 mm chokes, minimum weight rises to 2000 lbs.
  • P2 CN Spec ECU #35835wordingwordingP2 Spec Line E engine notes clarify oil system, ECU, and exhaust remain unrestricted; wording only.
  • P2 E&O - Correct FIA Group CN spec line notes #35900wordingwordingP2 FIA Group CN notes clarify V de V European Proto Endurance Challenge bodywork, rear diffuser, wing, wheels, assisted shifting allowed; regulations link provided.
  • GTL 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.
  • GTL GT Direct Injection allowance and rules #35437engineadded · engineGT1, GT2, GT3, GTL, GTX Direct Injection now permitted if original equipment.
  • GTL 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.
  • STL ST Electric-Assisted Steering Systems #35066aeroadded · aeroSTL and STU now permit electric power steering pumps, OEM electric-assisted steering, or column-mounted electric steering assist systems.
  • STL BOP Adjustments #35112weightfaster · weightSTL normally aspirated minimum weights reduced: 1900cc to 2540 lbs, 1950cc to 2583 lbs, 2000cc to 2625 lbs; short-wheelbase FWD adds 1.25%; Honda B16/B17/B18C1 throttle to 51mm, B18C Type R and Mazda MZR to 50mm.
  • STL Mazda 12A #35320engineremoved · engineSTL Mazda 12A: 5th and 6th intake port actuators and valves may no longer be removed or disabled.
  • GTL Rotary Engine 12A Rotor Housings #35131engineadded · engineGTL 12A rotary engines may machine and use 13B housing to O.E. 12A spec across all port types.
  • GTL Request to Include Toyota GR86 in GTL #35198cars addedaddedGTL Toyota DR86 2021–2024 added to class.
  • GTL Errors and Omissions, GTL engines & Cars #35226wordingwordingGTL BMW Mini model years changed to 2002-2013.
  • P2 E&O - Clarify B.1 modified engine range in AMAC spec lines #35225wordingwordingP2 AMAC and related cars: clarified B.1 modified engine range to 2008 and older stock engines only, with 38mm restrictor and 1025 lbs minimum weight.
  • P2 Replacement Engine Crankcase for 07/08 Suzuki GSX-R1000 Engines #35340engineadded · engineP2 Suzuki GSX-R1000 engine: 2007–2008 crankcase 11300-21860 may be replaced with 2016–2019 GSX-S1000 part 11301-04840.
  • STL Alternate Carburetor Request for 79-85 RX7 12a #35181engineadded · engineSTL 79-85 RX7 12A now allows auto-type 2 bbl carburetor with 42mm choke on dual-y manifold, not just stock Nikki.
  • GTL Small Engines in GT Lite #34842weightfaster · weightGTL small unrestricted engines under 1399cc lose 38–79 lbs across Alfa, AMC, Triumph, Mini, Sprite, Fiat, Ford, Honda, Mazda, Nissan, Subaru, Toyota, Volkswagen.
  • GTL Request to Classify Honda Fit body in GTL #35020cars addedaddedGTL Honda Fit 2009-13 2-door FWD added with 99.0 in wheelbase, alternate 94.0 and 97.0 in.
  • GTL 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.
  • P2 Correct Table 1 for Engine Date Range Specifications #35182wordingwordingP2 Table 1 engine date ranges clarified: Stock Engine replaced with specific marques Suzuki, Yamaha, Honda, BMW for 2009-newer and 2008-older rows.
  • GTL Weight for Nissan Sentra/200SX A 1400's #34918weight -50 lbsfaster · weightGTL Nissan Sentra/200SX A 1400 minimum weight reduced to 1800 lbs.
Virginia International Raceway Runoffs 20232023-09-231:48.590Greg Gyann · fastest of 12 · top 5 within 1.7s+1.024s (+0.95%)1:48.829Lucian Pancea · fastest of 11 · top 5 within 0.9s-27.005s (-19.88%)150.9Lucian Pancea-0.2 mph (-0.2%)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%)+27.400squal +26.396s125.2%qual 124.3%2:09.564Peter Shadowen · fastest of 11 · top 5 within 4.9s+1.775s (+1.39%)2:11.277Graham Fuller · fastest of 10 · top 5 within 2.4s-9.903s (-7.01%)142.7Peter Shadowen+6.7 mph (+4.9%)+22.448squal +20.974s120.6%qual 119.3%2:05.779Danny Steyn · fastest of 22 · top 5 within 3.4s+0.305s (+0.24%)2:06.682Joe Moser · fastest of 20 · top 5 within 1.5s-1.150s (-0.90%)131.8Danny Steyn+0.1 mph (+0.1%)+17.853squal +17.189s116.4%qual 115.8%
18 rule changes (P2: 8, SM: 1, GTL: 7, STL: 2)6 cars added · 3 engine · 2 weight · 7 wording · STL ITA and ITS RX7, and ITS/ITA/ITB/ITC 1985+ models clarified to require tires per 9.1.4.2. · Fields Cardinal V8 added to GT1 with Ford V8 engine, 4.9L, 2100 lbs, fuel injection. · P2 minimum side body height must equal front axle centerline height, viewed from side. · P2 closed cockpit single seat cars now prohibited unless Table 1 spec line permits. · P2 engine table spec line B.1 redundant effective date language removed and table updated. · P2 motorcycle restrictor reduced 35mm to 34mm for 2011+ Kawasaki; minimum weights increased to 1100 lbs for 2009+ engines; cockpit length corrected to 23.622 inches. · GTL 3K, 4K, 5K Toyota engines may now use 4Y block only. · GT2 and GTL add Toyota 4A-F and 4A-FE 1.6L DOHC 16V engines as permitted options. · Sebeco NP01-EVO and Elan NP01 added to P2 with Mazda 2.0L MZR, no restrictor required, 1600 lb minimum weight. · P2 Radical SR3/SR4, Cup, Club Sport, Pro-Sport, PR6: assisted shifting clarified from A-assisted to Aassisted; Cup engine restrictor changed from Unrestricted to Not required. · P2 chassis now allows composite materials partially installed; anti-intrusion panels attachment simplified; Stohr and converted models clarified. · SM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore. · Spec MX5 in STL allows ACT clutch 0000-02-5004-G6, wheels 17x8, Toyo RR and RA1 235-40-17 tyres, or alternatives on 17x7 per rules. · GTL Fiat X1/9 1500 Limited Prep minimum weight increases to 2000 lbs from 1835 lbs. · GT2 TA2 and GTA throttle body part numbers updated to GM 12570790 or Edelbrock 33869/3870. · GTL adds Ford Festiva 1988-1993 FWD hatchback with Mazda B3 1324cc engine. · GTL adds Toyota G16E-GTS 1618cc DOHC 3-cyl engine, 1945 lbs, SIR, no turbo or direct injection.showhide
  • STL Clarify STL table B - IT spec notes on Tires #34187wordingwordingSTL ITA and ITS RX7, and ITS/ITA/ITB/ITC 1985+ models clarified to require tires per 9.1.4.2.
  • GTL Please classify Fields Cardinal V8 #33784cars addedaddedFields Cardinal V8 added to GT1 with Ford V8 engine, 4.9L, 2100 lbs, fuel injection.
  • P2 Clarify minimum side body height requirement #34143wordingwordingP2 minimum side body height must equal front axle centerline height, viewed from side.
  • P2 Clarify closed cockpit single seat car allowance #34144wordingwordingP2 closed cockpit single seat cars now prohibited unless Table 1 spec line permits.
  • P2 Remove redundant effective date language and update engine table #34012wordingwordingP2 engine table spec line B.1 redundant effective date language removed and table updated.
  • P2 E&O - Correct dimensional equivalents #34038enginefaster · engineP2 motorcycle restrictor reduced 35mm to 34mm for 2011+ Kawasaki; minimum weights increased to 1100 lbs for 2009+ engines; cockpit length corrected to 23.622 inches.
  • GTL Toyota 4Y Engine Classification Request #33562engineadded · engineGTL 3K, 4K, 5K Toyota engines may now use 4Y block only.
  • GTL Toyota 4A-F and 4A-FE 1.6L DOHC 16V Engine Request #33415cars addedaddedGT2 and GTL add Toyota 4A-F and 4A-FE 1.6L DOHC 16V engines as permitted options.
  • P2 Request to Classify Sebeco NP01 #33378cars addedaddedSebeco NP01-EVO and Elan NP01 added to P2 with Mazda 2.0L MZR, no restrictor required, 1600 lb minimum weight.
  • P2 Radical spec line clarifications #33485wordingwordingP2 Radical SR3/SR4, Cup, Club Sport, Pro-Sport, PR6: assisted shifting clarified from A-assisted to Aassisted; Cup engine restrictor changed from Unrestricted to Not required.
  • P2 E&O original class intent #33519wordingwordingP2 chassis now allows composite materials partially installed; anti-intrusion panels attachment simplified; Stohr and converted models clarified.
  • P2 Update Engine Table Spec Line B.1 #33608engine
  • 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.
  • STL Spec MX5 in STL #33473cars addedaddedSpec MX5 in STL allows ACT clutch 0000-02-5004-G6, wheels 17x8, Toyo RR and RA1 235-40-17 tyres, or alternatives on 17x7 per rules.
  • GTL Fiat HP Limited Prep X1/9 Weight in GTL #33297weightslower · weightGTL Fiat X1/9 1500 Limited Prep minimum weight increases to 2000 lbs from 1835 lbs.
  • GTL GT2 (TA2)/GTA Part Number Update #33315wordingwordingGT2 TA2 and GTA throttle body part numbers updated to GM 12570790 or Edelbrock 33869/3870.
  • GTL Request to add Ford Festiva to GTL #33335cars addedaddedGTL adds Ford Festiva 1988-1993 FWD hatchback with Mazda B3 1324cc engine.
  • GTL Engine Request #33064cars addedaddedGTL adds Toyota G16E-GTS 1618cc DOHC 3-cyl engine, 1945 lbs, SIR, no turbo or direct injection.
Virginia International Raceway Runoffs 20222022-09-241:47.566Tim Day Jr · fastest of 12 · top 5 within 3.0s-1.545s (-1.42%)2:15.834Greg Gyann · fastest of 12 · top 5 within 10.1s+25.576s (+23.20%)151.1Robert Iversen+1.8 mph (+1.2%)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%)+3.273squal +27.098s102.4%qual 125.2%2:07.789Peter Shadowen · fastest of 14 · top 5 within 2.2s+0.792s (+0.62%)2:21.180Michael Lewis · fastest of 13 · top 5 within 2.1s+13.343s (+10.44%)136.0Peter Shadowen+4.9 mph (+3.7%)+5.346squal +20.223s103.9%qual 118.8%2:05.474Danny Steyn · fastest of 24 · top 5 within 2.3s-1.729s (-1.36%)2:07.832Danny Steyn · fastest of 22 · top 5 within 1.9s+0.559s (+0.44%)131.7Trever Degioanni-3.2 mph (-2.3%)-8.002squal +17.908s94.1%qual 116.6%
19 rule changes (P2: 10, SM: 1, GTL: 3, STL: 5)3 cars added · 2 weight · 1 engine · 1 tyres & wheels · 11 wording · 1 other · GT1, GT2, GT3, GTL, GTX tail lights may now be original style or custom panel graphic with functioning red LED brake lamps. · P2 chassis construction clarified: full composite allowed; partial composite must roll without composite parts installed. · P2 classification wording cleaned up in GCR section 9.1.8.C and GCR contents. · P2 Oldsmobile cam rules correct spelling from 'after market' to 'aftermarket' in two sections. · SM Majors must run authorized Penske shock and mount; Regional competitors not required until further evaluation. · Ginetta G40 added to GTL with Ford Zetec 1796cc engine, 2050 lbs minimum weight, 22.5mm SIR. · P2 adds Beasley B2 at 1350 lbs with Mazda 12A, 40.5mm venturi, and up to 16.5in wing chord. · P2 wings: terminology change from 'cord' to 'chord', and 'only' removed from Bobsy and Jondal notes. · P2 Converted F5 cars renamed F500, must retain F500 suspension, minimum width 55 inches. · STU single throttle body weight reduction removed; minimum weights revised down to 2990 lbs at 3000cc from 3300 lbs. · STL and STU Improved Touring vehicles must now conform to section 9.1.4 Tires & Wheels. · P2 motorcycle engines gain 5cc to 1505cc max, two-stroke gains 5cc to 1205cc max, automotive engines add 50 lbs minimum weight to 1350 lbs. · P2 Control Area definition clarified: rectangular zone from rear edge of front tires to front edge of rear tires, full car width. · STL/STU intake manifold and cylinder head porting clarified as free; intake and exhaust porting wording removed. · STL Mazda Renesis flat plate restrictor increases from 55mm to 60mm. · STL 79-85 RX7 12A allows emissions removal and jet correction on stock Nikki carb. · P2 specification line B.1 engine table entry amended; details of change not provided in excerpt. · P2 Control Area definition clarified: rear tire edge and front tire edge bounds, car's lower surface width, floor extensions and aerodynamic attachments included, vertical structures prohibited. · GT3 Volkswagen Fun Cup Beetle EVO3 classified, sealed SOHC 1984cc engine, 2060 lbs minimum weight.showhide
  • GTL 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.
  • P2 E&O Clarification of Chassis Construction Requirements #32469wordingwordingP2 chassis construction clarified: full composite allowed; partial composite must roll without composite parts installed.
  • P2 Clean up P2 wording #32525wordingwordingP2 classification wording cleaned up in GCR section 9.1.8.C and GCR contents.
  • P2 After Market to Aftermarket #32373wordingwordingP2 Oldsmobile cam rules correct spelling from 'after market' to 'aftermarket' in two sections.
  • 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.
  • GTL Request to Classify Ginetta G40 in GTL #31599cars addedaddedGinetta G40 added to GTL with Ford Zetec 1796cc engine, 2050 lbs minimum weight, 22.5mm SIR.
  • P2 Add spec line for Beasley B2 #32147cars addedaddedP2 adds Beasley B2 at 1350 lbs with Mazda 12A, 40.5mm venturi, and up to 16.5in wing chord.
  • P2 E&O Table 1 spec line wing terminology #32148wordingwordingP2 wings: terminology change from 'cord' to 'chord', and 'only' removed from Bobsy and Jondal notes.
  • P2 E&O class name #32196wordingwordingP2 Converted F5 cars renamed F500, must retain F500 suspension, minimum width 55 inches.
  • STL Single TB Weight Modifiers #31449weightfaster · weightSTU single throttle body weight reduction removed; minimum weights revised down to 2990 lbs at 3000cc from 3300 lbs.
  • STL Improved Touring Tires #32063tyres & wheelstyres & wheelsSTL and STU Improved Touring vehicles must now conform to section 9.1.4 Tires & Wheels.
  • P2 E&O Engine section #31969weightslower · weightP2 motorcycle engines gain 5cc to 1505cc max, two-stroke gains 5cc to 1205cc max, automotive engines add 50 lbs minimum weight to 1350 lbs.
  • P2 E&O letter #31539 – Control Area definition #31783wordingwordingP2 Control Area definition clarified: rectangular zone from rear edge of front tires to front edge of rear tires, full car width.
  • STL Throttling Device Clarification #31323wordingwordingSTL/STU intake manifold and cylinder head porting clarified as free; intake and exhaust porting wording removed.
  • STL Mazda Renesis Restriction #31467enginefaster · engineSTL Mazda Renesis flat plate restrictor increases from 55mm to 60mm.
  • STL Clarification of 79-85 RX7 Spec line #31621wordingwordingSTL 79-85 RX7 12A allows emissions removal and jet correction on stock Nikki carb.
  • P2 BoP adjustment effective 1-1-22 #31538otherunclearP2 specification line B.1 engine table entry amended; details of change not provided in excerpt.
  • P2 E&O clarification of "Control Area" definition #31539wordingwordingP2 Control Area definition clarified: rear tire edge and front tire edge bounds, car's lower surface width, floor extensions and aerodynamic attachments included, vertical structures prohibited.
  • GTL Request car classification #31032cars addedaddedGT3 Volkswagen Fun Cup Beetle EVO3 classified, sealed SOHC 1984cc engine, 2060 lbs minimum weight.
Indianapolis Motor Speedway Runoffs 20212021-09-251:33.235Tim Day Jr · fastest of 16 · top 5 within 3.3s+1.409s (+1.53%)1:35.322Tim Day Jr · fastest of 10 · top 5 within 4.8s+2.841s (+3.07%)150.3Robert Iversen1:57.695Brian 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+23.515squal +24.460s124.7%qual 126.2%1:51.819Christopher Bovis · fastest of 22 · top 5 within 1.8s+1.488s (+1.35%)1:51.952Scott Twomey · fastest of 19 · top 5 within 1.7s-0.116s (-0.10%)129.5Brian Linn+16.630squal +18.584s117.4%qual 119.9%1:51.665Danny Steyn · fastest of 42 · top 5 within 1.7s-0.982s (-0.87%)2:02.711Joe Moser · fastest of 37 · top 5 within 3.2s+10.122s (+8.99%)131.8Max Gee+27.389squal +18.430s128.7%qual 119.8%
32 rule changes (P2: 8, SM: 1, GTL: 8, STL: 15)6 cars added · 5 engine · 3 aero · 3 induction · 2 weight · 1 suspension & brakes · 9 wording · 3 other · P2 CN Honda K20A-FD2 engine rebuild clarified: balancing, porting, polishing prohibited; valve jobs and honing must follow factory procedures. · STL Mazda Spec MX-5 removes redundant specification line referencing 2014 regulations. · GTA part numbers updated: 0-80541-1 to 0-80541-2 in two locations and 6010 to 6014X in TA2 Appendix. · P2 Converted F5 cars must retain F5 suspension and meet P2 non-spec requirements except minimum width is 55 inches. · P2 minimum body width clarified: cannot extend inward beyond vertical plane through tire centerlines. · GTL Honda B18 split into B18A/B at 1797 cc 2050 lbs and B18C at 1834 cc 2065 lbs. · GTL Nissan B13 Sentra may have hood bulge maximum 1.5 inches high by 10.0 long by 6.0 wide. · unclear · STL Volkswagen 2.0L TFSI 1984 cc engine permitted without turbocharger, meeting all other STL specs. · P2 tonneau covers now allowed to meet minimum dimensions; cockpit equipment attachment wording clarified. · P2 removes effective date 01/01/2021 from six car spec lines in Table 1. · P2 engine specs B.1, B.2, B.3 limited to maximum 4 valves per cylinder. · STL Pontiac Solstice/Saturn Sky allowed 4 inch ride height. · STL Mazda B5 DOHC added to class; must meet all STL regulations. · STL Honda B16A (JDM) restrictor reduced from 54mm to 53mm. · SM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture. · ST oil coolers and filters now explicitly listed as addable or substitutable parts in vents and breathers section. · GTL Mazda 12A SIR increases to 29mm, minimum weight rises to 2000 lbs, 28mm SIR option with 175 lb penalty removed. · P2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front, 14–15 rear wheel width. · STL GM Ecotec LNF now permits any Ecotec engine family with 55mm flat plate restrictor. · ST 90-05 Mazda Miata allowed alternate front wheel hub Mazda Motorsports Development Part #0000-04-5HUB-S1. · GTL adds FIAT X-1/9 Bertone 1500 SOHC, 1498 cc, 2000 lbs, fuel injection or carburetors permitted. · ST cars may now relocate ABS actuation hardware and wiring anywhere in the engine compartment. · STL rear wing trailing edge may be mounted no further rearward than the center of the rearmost part approved bodywork. · STL alternate transmissions now allow OEM gear sets and input shaft modifications for fitment. · GTL Nissan MRA8DE 1.8L engine added, 1797 cc, DOHC, 2050 lbs minimum weight. · GTL Mazda 13B SIR increases from 26 mm to 28 mm; 27 mm option with 175 lbs removed. · STL RWD strut-front cars lose 2.5% weight penalty, others lose 3% penalty for FWD parity. · STL Honda F20C drops 2% weight penalty, minimum weight reduced. · STL Honda B16/B17/B18C1 restrictor reduced to 53mm, B18C variants and Mazda MZR to 52mm. · P2 motorcycle-engine cars: 2009+ stock 37mm restrictor, 2008- stock 35mm, modified 1075 lbs. Honda K20A 50mm restrictor. Various spec cars: restrictors increased or decreased 0.5–3mm. · ST aero devices and reference areas must include end plates, exclude fasteners under 1/2" protrusion.showhide
  • P2 P2 CN Engine Rebuild Clarification #31000wordingwordingP2 CN Honda K20A-FD2 engine rebuild clarified: balancing, porting, polishing prohibited; valve jobs and honing must follow factory procedures.
  • STL Request to clean up Spec MX-5 Redundancy #31069wordingwordingSTL Mazda Spec MX-5 removes redundant specification line referencing 2014 regulations.
  • GTL 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.
  • P2 F5 P2 Conversion #30856wordingwordingP2 Converted F5 cars must retain F5 suspension and meet P2 non-spec requirements except minimum width is 55 inches.
  • P2 Clarify minimum body width requirement #30859wordingwordingP2 minimum body width clarified: cannot extend inward beyond vertical plane through tire centerlines.
  • GTL Request clarification for the Honda B18a,bVS B18c #30482cars addedaddedGTL Honda B18 split into B18A/B at 1797 cc 2050 lbs and B18C at 1834 cc 2065 lbs.
  • GTL Request to Allow Hood Bulge on Nissan B13 Sentra #30504aeroadded · aeroGTL Nissan B13 Sentra may have hood bulge maximum 1.5 inches high by 10.0 long by 6.0 wide.
  • GTL Request BMW E21 Classing #30582otherunclearunclear
  • STL VW Engine Request #30625engineadded · engineSTL Volkswagen 2.0L TFSI 1984 cc engine permitted without turbocharger, meeting all other STL specs.
  • P2 E&O tonneau cover provision in cockpit opening section #30459wordingwordingP2 tonneau covers now allowed to meet minimum dimensions; cockpit equipment attachment wording clarified.
  • P2 Remove effective dates in Table 1 #30468wordingwordingP2 removes effective date 01/01/2021 from six car spec lines in Table 1.
  • P2 E&O Maximum Valves Per Cylinder #30560engineengineP2 engine specs B.1, B.2, B.3 limited to maximum 4 valves per cylinder.
  • STL Solstice Ride Height #30183otheraddedSTL Pontiac Solstice/Saturn Sky allowed 4 inch ride height.
  • STL Request Mazda B5 DOHC #30420cars addedaddedSTL Mazda B5 DOHC added to class; must meet all STL regulations.
  • STL Honda B16A (JDM) Restrictor change #30531engineslower · engineSTL Honda B16A (JDM) restrictor reduced from 54mm to 53mm.
  • SM Updates - Obsolete Parts & BOP Parts #30438wordingaddedSM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture.
  • STL ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wordingwordingST oil coolers and filters now explicitly listed as addable or substitutable parts in vents and breathers section.
  • GTL Request for Help for Mazda 12A #29754induction +50 lbsslower · inductionGTL Mazda 12A SIR increases to 29mm, minimum weight rises to 2000 lbs, 28mm SIR option with 175 lb penalty removed.
  • P2 Add a new spec line for a 2-cycle, 3-cylinder engine up to 820cc #30272cars addedaddedP2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front, 14–15 rear wheel width.
  • STL GM Ecotec engines in STL #30247engineadded · engineSTL GM Ecotec LNF now permits any Ecotec engine family with 55mm flat plate restrictor.
  • STL Super Touring Alternate Miata Hubs #30345cars addedaddedST 90-05 Mazda Miata allowed alternate front wheel hub Mazda Motorsports Development Part #0000-04-5HUB-S1.
  • GTL Request LP HP Fiat X1/9 & Bertone 1500 to GTL #30058cars addedaddedGTL adds FIAT X-1/9 Bertone 1500 SOHC, 1498 cc, 2000 lbs, fuel injection or carburetors permitted.
  • STL Brake Component Relocation #29990suspension & brakessuspension & brakesST cars may now relocate ABS actuation hardware and wiring anywhere in the engine compartment.
  • STL Super Touring Wing Clarification #30111aeroaeroSTL rear wing trailing edge may be mounted no further rearward than the center of the rearmost part approved bodywork.
  • STL Transmission Options #30118otheraddedSTL alternate transmissions now allow OEM gear sets and input shaft modifications for fitment.
  • GTL Please Add GTL Nissan 1.8L Engine MRA8DE #29805cars addedaddedGTL Nissan MRA8DE 1.8L engine added, 1797 cc, DOHC, 2050 lbs minimum weight.
  • GTL Increase 13b SIR size #29867inductionfaster · inductionGTL Mazda 13B SIR increases from 26 mm to 28 mm; 27 mm option with 175 lbs removed.
  • STL Request for FWD and RWD Parity #29728weightfaster · weightSTL RWD strut-front cars lose 2.5% weight penalty, others lose 3% penalty for FWD parity.
  • STL Request to Remove Honda F20C 2% Weight Penalty #29815weightfaster · weightSTL Honda F20C drops 2% weight penalty, minimum weight reduced.
  • STL Request for FWD and RWD Parity #30023inductionslower · inductionSTL Honda B16/B17/B18C1 restrictor reduced to 53mm, B18C variants and Mazda MZR to 52mm.
  • P2 Balance of Performance adjustments effective 01-01-2021 #29822engineunclearP2 motorcycle-engine cars: 2009+ stock 37mm restrictor, 2008- stock 35mm, modified 1075 lbs. Honda K20A 50mm restrictor. Various spec cars: restrictors increased or decreased 0.5–3mm.
  • STL Request clarification on wing measurement #29640aeroaeroST aero devices and reference areas must include end plates, exclude fasteners under 1/2" protrusion.
Road America Runoffs 20202020-10-022:08.514Robert Iversen · fastest of 12 · top 5 within 3.0s2:09.793Robert Iversen · fastest of 12 · top 5 within 3.9s153.1Robert Iversen2:42.209Kyle Greenhill · fastest of 77 · top 5 within 0.5s2:43.748Preston Pardus · fastest of 75 · top 5 within 1.0s121.3Kyle Greenhill+33.955squal +33.695s126.2%qual 126.2%2:31.943Chris Bovis · fastest of 14 · top 5 within 6.3s2:31.601Peter Shadowen · fastest of 14 · top 5 within 7.2s131.4Peter Shadowen+21.808squal +23.429s116.8%qual 118.2%2:31.420Danny Steyn · fastest of 33 · top 5 within 3.1s2:32.115Joe Moser · fastest of 30 · top 5 within 1.5s132.9Darin Treakle+22.322squal +22.906s117.2%qual 117.8%
36 rule changes (P2: 6, SM: 2, GTL: 17, STL: 11)8 cars added · 5 aero · 5 engine · 2 induction · 2 suspension & brakes · 1 weight · 11 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. · GT1/GT2/GT3/GTL/GTX turbocharging and supercharging now permitted if listed on spec line. · P2 rear wing rules clarified: standard wing 6×12 inches, end plates 14-inch square; alternate 1-meter formula wing 110cm wide, 9×18 inches, end plates 14×18 inches. · GTL Mazda 13B restrictor increases from 24mm to 26mm SIR, minimum weight rises to 2125 lbs, alternative 27mm SIR option adds 175 lbs. · SM rear brake caliper may use single bracket under upper retaining bolt head to prevent pin failure. · STL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis percentage additions, subtractions, and fixed pounds. · STL STU rear wing Gurney flap terminology clarified from wicker to Gurney flap in mounting and chord rules. · GTL: Toyota MR2 Spyder 1999–2007 newly classified for GTL competition. · 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. · GTL Mazda 13B restrictor size addressed in response to letter 28518; see that letter for details. · GT3 and STU add Borg-Warner EFR6258 turbocharger to approved turbo lists. · GTL SIR stall test procedure clarified: system tested as raced, competitor must prevent air bypass behind restrictor. · Elan NP01 added to P2 Table 1 as Spec Line car with 2000cc displacement and 42mm restrictor. · STL adds Mazda MX-5 Global Cup 16-18 at 2450 lbs minimum and 2019 at 2550 lbs minimum. · STL Mazda MX-5 Club 06-15 allowed header part number 0000-06-5407-NC. · STL Acura/Honda B18 and B18C engines: restrictor sizes swapped, B18C1 removed from allowed variants. · GTL wing mount openings excluded from square inch area limit. · P2 Enterprises Sports Racer now permits 55mm flat plate intake restrictor Part # WM303013 as alternative to SIR. · STL Honda B18 loses 53mm restrictor requirement; B18C1 added with 54mm restrictor, B18C1 removed from other variants. · P2 Enterprise Sports Racer 2.3L engine must use SIR or Flat Plate restrictor meeting peak horsepower, sized in whole or 0.5mm increments. · STU GM Ecotech LNF now permitted without turbo, with LE5 head and intake manifold, meeting STL specs. · STL Mazda MZR restrictor reduced from 54 mm to 53 mm. · STL Mazda MZR restrictor reduces from 55 mm to 53 mm. · GTL wing mounting posts limited to 85 square inches exposed area each, measured flat from side view. · GTL wing mounting posts limited to 85 square inches each, measured flat from side view. · GTL wing endplates maximum area increased to 64 square inches from 8.5 by 3.0 inches rectangle. · GTL Mazda 12A street port minimum weight drops to 1950 lbs. · P2 electronic throttle control wording clarified: ETC permitted if stock ECU throttle pedal activates original throttle shaft mechanism. · STL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL to notes. · 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. · GTL adds Jetta Mk1 two-door classification effective 2020-01-01. · P2 adds BMW to permitted motorcycle-based engines alongside Kawasaki, Suzuki, Yamaha, Honda. · GTL Honda CRX 84-87 and 88-91 lose permission to use IRS with 2.5% weight penalty.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.
  • GTL GT Category Wording #29193wordingaddedGT1/GT2/GT3/GTL/GTX turbocharging and supercharging now permitted if listed on spec line.
  • P2 E&O clarification of P2 rear wing requirements #29205aeroaeroP2 rear wing rules clarified: standard wing 6×12 inches, end plates 14-inch square; alternate 1-meter formula wing 110cm wide, 9×18 inches, end plates 14×18 inches.
  • GTL Request to change the Mazda 13b restrictor size #28518induction +175 lbsfaster · inductionGTL Mazda 13B restrictor increases from 24mm to 26mm SIR, minimum weight rises to 2125 lbs, alternative 27mm SIR option adds 175 lbs.
  • 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.
  • STL Minimum Weight Determination #27695wordingwordingSTL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis percentage additions, subtractions, and fixed pounds.
  • STL ST Gurney flap Wicker clarification #29012wordingwordingSTL STU rear wing Gurney flap terminology clarified from wicker to Gurney flap in mounting and chord rules.
  • GTL Request to classify 1999-2007 Toyota MR2 Spyder body #28870cars addedaddedGTL: Toyota MR2 Spyder 1999–2007 newly classified for GTL competition.
  • GTL TA2 Gurney flap wicker clarification #28874wordingwordingTA2 Gurney flap wording clarified: replace 'wicker bill' and 'wicker' with 'Gurney flap' throughout wing specifications.
  • GTL STO Gurney flap wicker clarification #28883wordingwordingSTO rear wing rules clarify that wicker is called Gurney flap in two places; no performance change.
  • GTL 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.
  • GTL Mazda 13b Restrictor Size Follow up to Letter 28518 #29015wordingunclearGTL Mazda 13B restrictor size addressed in response to letter 28518; see that letter for details.
  • STL Request for Addition to GT3 Approved Turbo List #27576cars addedaddedGT3 and STU add Borg-Warner EFR6258 turbocharger to approved turbo lists.
  • GTL Stall Test #28709wordingwordingGTL SIR stall test procedure clarified: system tested as raced, competitor must prevent air bypass behind restrictor.
  • P2 Classify Elan NP01 in P2 Table 1 #28812cars addedaddedElan NP01 added to P2 Table 1 as Spec Line car with 2000cc displacement and 42mm restrictor.
  • STL Request to add 2016-2019 GMX-5 Spec line #28604cars addedaddedSTL adds Mazda MX-5 Global Cup 16-18 at 2450 lbs minimum and 2019 at 2550 lbs minimum.
  • STL Request to update PN for MX-5 #28622cars addedaddedSTL Mazda MX-5 Club 06-15 allowed header part number 0000-06-5407-NC.
  • STL Correction - Clarification Honda/Acura B18B engine Letter # 26209 #28873wordingwordingSTL Acura/Honda B18 and B18C engines: restrictor sizes swapped, B18C1 removed from allowed variants.
  • GTL GTL Wing Rule #28754aeroadded · aeroGTL wing mount openings excluded from square inch area limit.
  • P2 SCCA Enterprises ESR / P2 engine restrictor testing #28669otheraddedP2 Enterprises Sports Racer now permits 55mm flat plate intake restrictor Part # WM303013 as alternative to SIR.
  • STL STL Honda B18 restrictor changes #28794enginefaster · engineSTL Honda B18 loses 53mm restrictor requirement; B18C1 added with 54mm restrictor, B18C1 removed from other variants.
  • P2 Add ESR inlet restrictor #27869inductionadded · inductionP2 Enterprise Sports Racer 2.3L engine must use SIR or Flat Plate restrictor meeting peak horsepower, sized in whole or 0.5mm increments.
  • STL Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0 #27884engineadded · engineSTU GM Ecotech LNF now permitted without turbo, with LE5 head and intake manifold, meeting STL specs.
  • STL Acura/Honda B18C engine chart. Reduce the current 54 mm flat plat #28663engineslower · engineSTL Mazda MZR restrictor reduced from 54 mm to 53 mm.
  • STL Mazda MZR engine chart. Reduce the current 55 mm flat plate to 53 #28664engineslower · engineSTL Mazda MZR restrictor reduces from 55 mm to 53 mm.
  • GTL Wing Mounting Upright Size #27641aeroaeroGTL wing mounting posts limited to 85 square inches exposed area each, measured flat from side view.
  • GTL Wing Mounting Upright Size #27641aeroaeroGTL wing mounting posts limited to 85 square inches each, measured flat from side view.
  • GTL GTL wing end plates addition #28243aerofaster · aeroGTL wing endplates maximum area increased to 64 square inches from 8.5 by 3.0 inches rectangle.
  • GTL Clarification to letter #27406 #28309weight -50 lbsfaster · weightGTL Mazda 12A street port minimum weight drops to 1950 lbs.
  • P2 Request for Fly by Wire Rule Wording Change #28247wordingwordingP2 electronic throttle control wording clarified: ETC permitted if stock ECU throttle pedal activates original throttle shaft mechanism.
  • STL Request to add wheel part numbers #28342cars addedaddedSTL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL to notes.
  • GTL Windshield Clips #27323otheraddedGT1, GT2, GT3, GTL, GTX may use bonded-glass factory windshields without clips or straps if attached per original specifications.
  • GTL 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.
  • GTL Request to Classify the MK1 two door Jetta #27648cars addedaddedGTL adds Jetta Mk1 two-door classification effective 2020-01-01.
  • P2 Request for addition of BMW Engine in P2 Engine Table #27821engineadded · engineP2 adds BMW to permitted motorcycle-based engines alongside Kawasaki, Suzuki, Yamaha, Honda.
  • GTL 88-91 Honda CRX Spec Line Correction #27233suspension & brakesremoved · suspension & brakesGTL Honda CRX 84-87 and 88-91 lose permission to use IRS with 2.5% weight penalty.
Virginia International Raceway Runoffs 20192019-10-051:49.111Robert Iversen · fastest of 14 · top 5 within 0.8s1:50.258Greg Gyann · fastest of 13 · top 5 within 0.4s149.4Robert Iversen2:14.552Todd Buras · fastest of 60 · top 5 within 0.2s2:16.459Elivan Goulart · fastest of 56 · top 5 within 0.4s119.8Jim Drago+26.201squal +25.441s123.8%qual 123.3%2:06.997Peter Shadowen · fastest of 19 · top 5 within 4.0s2:07.837Bill Ball · fastest of 18 · top 5 within 4.2s131.1Peter Shadowen+17.579squal +17.886s115.9%qual 116.4%2:07.203Danny Steyn · fastest of 36 · top 5 within 1.8s2:07.273Cliff Ira · fastest of 35 · top 5 within 1.4s134.8Cliff Ira+17.015squal +18.092s115.4%qual 116.6%
37 rule changes (P2: 9, SM: 4, GTL: 13, STL: 11)9 engine · 8 cars added · 3 weight · 2 induction · 1 removed · 9 wording · 5 other · P2 Honda K20A-FD2 non-composite chassis intake restrictor note clarified; restrictor implementation date removed. · STL adds Mazda Spec MX-5 Challenge, 2000cc displacement, 2500 lb minimum weight, with mandatory Roush, Penske, Eibach, and other specified components. · GTL Fun Cup Beetle engine weight set to 1850 lbs with Weber DMTL 32/34 induction. · P2 motorcycle engines: Stock restrictor to 35mm, Modified to 34mm; weights up to 1025 and 1125 lbs respectively. B.5 restrictor to 33mm, weight to 1185 lbs. · GTL Fun Cup Beetle removes reference to VW engine table; Fun Cup engines only permitted. · GTL Honda CRZ 10-14, CRZ 15-16, and Insight 00-06 gain alternate wheelbase option of 90.6 inches. · P2 cars limited to power application on maximum two wheels. · STU allows alternate intake manifolds on case-by-case basis; stock throttle device and manifold otherwise required. · P2 Enterprise minimum weight increased to 1375 lbs.; peak horsepower of sealed ESR engine reduced per CRB specification. · STL Acura/Honda B18 except C engine restrictor increased from 53mm to 54mm flat plate. · GTL Fun Cup Beetle added, all model years, 2-door RWD, 94.5 in wheelbase, VW Fun Cup spec chassis. · GTX tube frame cars now allowed fuel injection with maximum 90mm throttle body. · GTX adds Ligier JS2 R classification with restrictor and minimum weight. · GTL Mazda 13B may use 25mm SIR with 175 lbs weight penalty added. · STL and STU ride height measurement clarified: lowest rocker panel point without driver, excluding pinch weld. · GT1 and GT2/3/Lite remove ride height ground clearance rules; cars may now touch ground when tires deflate. · GTL Mazda 12A may use 28mm SIR plus 175 lbs. · GTL: Ford Mustang 94-04 body newly classified for GTL racing. · P2 stock and modified engines get smaller restrictors (35.0mm, 34.0mm, 33.0mm) and heavier minimums (1025, 1125, 1185 lbs). · P2 Line A.1 restrictor reduced from 40mm to 38mm. · SM fuel pump and filter now permitted as Mazda or OEM equivalent part. · STL adds VW 1.8L R4 20VT 1781 cc, 1781 minimum weight, naturally aspirated only. · STL Mazda Renesis minimum weight reduced to 2700 lbs. · STL Mazda MX-5 Cup brake pad compound now open. · STL adds Acura/Honda B18C1 GSR with 1797cc displacement, 54mm flat plate restrictor required, porting outside 1" allowance prohibited. · STL Mazda 12 and 13B now permit port matching; porting ban removed. · 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. · GTL Mini 1275–1399 Iron and Aluminum Crossflow with OE common sump gearbox reduce weight by 125 lbs, up from 50 lbs. · GTL BMC thru Rover Group removes four long inactive Mini engines: 948, 970, 1071, 1098. · 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. · P2 Spec Line cars now allow 1345cc Hayabusa stock engines at 1050 lb minimum with 30mm restrictor. · P2 Group CN Honda K20A-FD2 55mm intake restrictor implementation delayed from 1 January to 3 March 2019. · P2 Honda K20A-FD2 Group CN must use stock intake manifold, 64mm throttle, 55mm restrictor at 1500 lbs minimum. · STL B17 now requires 54mm flat plate restrictor; B18C Type R variants move to 54mm restrictor, weight chart baseline. · STL Mazda Miata removes maximum displacement limit; minimum weight corrected to unspecified figure.showhide
  • P2 Update Engine Table Line E notes #27414wordingwordingP2 Honda K20A-FD2 non-composite chassis intake restrictor note clarified; restrictor implementation date removed.
  • STL Request to Classify Spec MX-5 Challenge in STL #27399cars addedaddedSTL adds Mazda Spec MX-5 Challenge, 2000cc displacement, 2500 lb minimum weight, with mandatory Roush, Penske, Eibach, and other specified components.
  • GTL Fun Cup Beetle #27334wordingwordingGTL Fun Cup Beetle engine weight set to 1850 lbs with Weber DMTL 32/34 induction.
  • P2 Update P2 Engine Table spec lines to reflect 3/1/2019 #27254engineslower · engineP2 motorcycle engines: Stock restrictor to 35mm, Modified to 34mm; weights up to 1025 and 1125 lbs respectively. B.5 restrictor to 33mm, weight to 1185 lbs.
  • GTL GTL #26960wordingwordingGTL Fun Cup Beetle removes reference to VW engine table; Fun Cup engines only permitted.
  • GTL Request CRZ wheelbase change #26896cars addedaddedGTL Honda CRZ 10-14, CRZ 15-16, and Insight 00-06 gain alternate wheelbase option of 90.6 inches.
  • P2 E&O Transmissions #27006engineslower · engineP2 cars limited to power application on maximum two wheels.
  • STL Request clarification for manifold and throttle in STU #27004wordingwordingSTU allows alternate intake manifolds on case-by-case basis; stock throttle device and manifold otherwise required.
  • P2 Request to restrict all cars #26246weightslower · weightP2 Enterprise minimum weight increased to 1375 lbs.; peak horsepower of sealed ESR engine reduced per CRB specification.
  • STL Request Restrictor Plate correction #26779enginefaster · engineSTL Acura/Honda B18 except C engine restrictor increased from 53mm to 54mm flat plate.
  • GTL Request to Classify VW Fun Cup Beetle #25986cars addedaddedGTL Fun Cup Beetle added, all model years, 2-door RWD, 94.5 in wheelbase, VW Fun Cup spec chassis.
  • GTL 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.
  • GTL Request to Classify Ligier JS2 R #26535cars addedaddedGTX adds Ligier JS2 R classification with restrictor and minimum weight.
  • GTL Request for GTL Mazda 13B SIR Increase with Penalty #26572engineadded · engineGTL Mazda 13B may use 25mm SIR with 175 lbs weight penalty added.
  • STL Request Ride Height Clarification #26597wordingwordingSTL and STU ride height measurement clarified: lowest rocker panel point without driver, excluding pinch weld.
  • GTL Request Ride Height Clarification #26600wordingfasterGT1 and GT2/3/Lite remove ride height ground clearance rules; cars may now touch ground when tires deflate.
  • GTL Request Mazda 12a Rotary SIR Increase #26081inductionadded · inductionGTL Mazda 12A may use 28mm SIR plus 175 lbs.
  • GTL Request to Classify Mustang 2 Body in GTL #26222cars addedaddedGTL: Ford Mustang 94-04 body newly classified for GTL racing.
  • P2 Change Engine Table Lines B.1 & B.5 #25777inductionslower · inductionP2 stock and modified engines get smaller restrictors (35.0mm, 34.0mm, 33.0mm) and heavier minimums (1025, 1125, 1185 lbs).
  • P2 Change Line A.1 restrictor size #26429engineslower · engineP2 Line A.1 restrictor reduced from 40mm to 38mm.
  • SM Request to allow aftermarket fuel filters. #26370otheraddedSM fuel pump and filter now permitted as Mazda or OEM equivalent part.
  • STL Request to Allow VW 1.8L Engine #25614cars addedaddedSTL adds VW 1.8L R4 20VT 1781 cc, 1781 minimum weight, naturally aspirated only.
  • STL Request to reduce weight of RX8 with Renesis rotary #25781weight -100 lbsfaster · weightSTL Mazda Renesis minimum weight reduced to 2700 lbs.
  • STL Request for Open Brake Pads On Mazda MX-5 Cup NC #25821otheraddedSTL Mazda MX-5 Cup brake pad compound now open.
  • STL Request to clarify B18C1 GSR Honda B motor table #26209cars addedaddedSTL adds Acura/Honda B18C1 GSR with 1797cc displacement, 54mm flat plate restrictor required, porting outside 1" allowance prohibited.
  • STL Port Matching #26415enginefaster · engineSTL Mazda 12 and 13B now permit port matching; porting ban removed.
  • 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.
  • GTL Request for GTL Mini Adjustments #25754weightfaster · weightGTL Mini 1275–1399 Iron and Aluminum Crossflow with OE common sump gearbox reduce weight by 125 lbs, up from 50 lbs.
  • GTL BMC thru Rover Group remove long inactive mini #25771removedremovedGTL BMC thru Rover Group removes four long inactive Mini engines: 948, 970, 1071, 1098.
  • GTL 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.
  • P2 Request to Allow 1345cc Hayabusa Engines for Spec Line P2 Cars #25595cars addedaddedP2 Spec Line cars now allow 1345cc Hayabusa stock engines at 1050 lb minimum with 30mm restrictor.
  • P2 Change CN inlet restrictor implementation date #25816wordingwordingP2 Group CN Honda K20A-FD2 55mm intake restrictor implementation delayed from 1 January to 3 March 2019.
  • P2 Clarify Honda K20A-FD2 parts requirement #25950engineslower · engineP2 Honda K20A-FD2 Group CN must use stock intake manifold, 64mm throttle, 55mm restrictor at 1500 lbs minimum.
  • STL Request to equalize FPR Reduction on all B-Series Vtec Engines #24746enginefaster · engineSTL B17 now requires 54mm flat plate restrictor; B18C Type R variants move to 54mm restrictor, weight chart baseline.
  • STL Request E&O for Mazda Miata Spec Line #25955otherunclearSTL Mazda Miata removes maximum displacement limit; minimum weight corrected to unspecified figure.
Sonoma Raceway Runoffs 20182018-10-101:28.784Tim Day Jr · fastest of 17 · top 5 within 5.0s1:32.071Chuck Bona · fastest of 18 · top 5 within 0.9s144.4Tim Day Jr1:54.355Ken Sutherland · fastest of 48 · top 5 within 0.7s1:55.278Michael Carter · fastest of 48 · top 5 within 0.3s102.2Danny Steyn+23.207squal +25.571s125.2%qual 128.8%1:47.885Troy Ermish · fastest of 20 · top 5 within 4.5s1:49.458Troy Ermish · fastest of 19 · top 5 within 3.6s109.3Charles Leonard+17.387squal +19.101s118.9%qual 121.5%1:49.138Danny Steyn · fastest of 19 · top 5 within 2.5s1:49.754Danny Steyn · fastest of 17 · top 5 within 2.5s103.2Craig McHaffie+17.683squal +20.354s119.2%qual 122.9%
No rule changes on record between these events
Indianapolis Motor Speedway Runoffs 20172017-09-251:31.826Jeff Shafer · fastest of 26 · top 5 within 4.9s1:32.481Jeff Shafer · fastest of 24 · top 5 within 3.8s1:58.306Chris Haldeman · fastest of 86 · top 5 within 0.5s1:59.100Michael Gagliardo · fastest of 83 · top 5 within 0.6s+26.619squal +26.480s128.8%qual 128.8%1:50.331Christopher Bovis · fastest of 26 · top 5 within 1.5s1:52.068Christopher Bovis · fastest of 20 · top 5 within 1.0s+19.587squal +18.505s121.2%qual 120.2%1:52.647Adam Roberts · fastest of 57 · top 5 within 0.8s1:52.589Eric Kutil · fastest of 50 · top 5 within 1.2s+20.108squal +20.821s121.7%qual 122.7%
No rule changes on record between these events
Mid-Ohio Sports Car Course Runoffs 20162016-09-191:20.188Jeff Shafer · fastest of 18 · top 5 within 4.0s1:20.904Jeff Shafer · fastest of 16 · top 5 within 2.2s1:40.514Justin Hille · fastest of 45 · top 5 within 0.3s1:40.764Michael Carter · fastest of 44 · top 5 within 0.3s+19.860squal +20.326s124.5%qual 125.3%1:35.377Wilson Wright · fastest of 28 · top 5 within 1.2s1:35.912Kyle Disque · fastest of 28 · top 5 within 1.1s+15.008squal +15.189s118.6%qual 118.9%1:35.439John Schmitt · fastest of 34 · top 5 within 1.5s1:36.625Kevin Boehm · fastest of 31 · top 5 within 0.6s+15.721squal +15.251s119.4%qual 119.0%
No rule changes on record between these events
Daytona International Speedway Runoffs 20152015-09-211:51.825Chris Farrell · fastest of 17 · top 5 within 3.6s1:52.355Jeff Shafer · fastest of 17 · top 5 within 2.8s2:18.661Andrew Carbonell · fastest of 62 · top 5 within 0.6s2:24.067Todd Lamb · fastest of 59 · top 5 within 0.8s+31.712squal +26.836s128.2%qual 124.0%2:11.387Jim Dentici · fastest of 10 · top 5 within 2.2s2:13.564Jim Dentici · fastest of 9 · top 5 within 2.0s+21.209squal +19.562s118.9%qual 117.5%2:09.672Kevin Boehm · fastest of 37 · top 5 within 2.5s2:10.269Kevin Boehm · fastest of 37 · top 5 within 2.1s+17.914squal +17.847s115.9%qual 116.0%

By track

TrackEventsTypical % of P2BestLatest
Road America4100.0%3 of 4 with P2100.0%Runoffs 2020100.0%Runoffs 2026
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 P2'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.