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BoP Lab / Classes / P1

P1 vs FF vs AS vs F5 pace at every track

Lap times across years say as much about the weather as the class. % of P1 is each class's best lap as a share of P1'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: P1 1:17.308 James Devenport, Runoffs 2016 qualifying · FF 1:29.213 Neil Verhagen, Runoffs 2016 qualifying · AS 1:30.651 Tom Sloe, Runoffs 2016 qualifying · F5 1:28.528 Calvin Stewart, Runoffs 2016 qualifying

1:402:002:2022 rule changes between Runoffs 2018 and Runoffs 201922 ▾30 rule changes between Runoffs 2019 and Runoffs 202030 ▾31 rule changes between Runoffs 2020 and Runoffs 202131 ▾18 rule changes between Runoffs 2021 and Runoffs 202218 ▾12 rule changes between Runoffs 2022 and Runoffs 202312 ▾19 rule changes between Runoffs 2023 and Runoffs 202419 ▾15 rule changes between Runoffs 2024 and Runoffs 202515 ▾15 rule changes between Runoffs 2025 and Runoffs 202615 ▾P1 race best at Runoffs 2015: 1:49.792 (Gianpaolo Ciancimino)Off the chart: P1 race best at Runoffs 2016: 1:19.407 (Gianpaolo Ciancimino)P1 race best at Runoffs 2017: 1:31.499 (Jim Devenport)P1 race best at Runoffs 2018: 1:28.786 (Perry Richardson)P1 race best at Runoffs 2019: 1:43.498 (Todd Slusher)P1 race best at Runoffs 2020: 2:01.870 (James French)P1 race best at Runoffs 2021: 1:29.225 (Lee Alexander)P1 race best at Runoffs 2022: 1:54.095 (John Mcaleer)P1 race best at Runoffs 2023: 1:44.329 (Todd Vanacore)P1 race best at Runoffs 2024: 2:00.418 (Matt Romer)P1 qualifying best at Runoffs 2015: 1:49.219 (Jim Downing)Off the chart: P1 qualifying best at Runoffs 2016: 1:17.308 (James Devenport)P1 qualifying best at Runoffs 2017: 1:30.794 (Jim Devenport)P1 qualifying best at Runoffs 2018: 1:27.714 (Todd Slusher)P1 qualifying best at Runoffs 2019: 1:42.674 (Todd Slusher)P1 qualifying best at Runoffs 2020: 2:01.101 (James French)P1 qualifying best at Runoffs 2021: 1:29.011 (Lee Alexander)P1 qualifying best at Runoffs 2022: 1:41.601 (Todd Slusher)P1 qualifying best at Runoffs 2023: 1:42.602 (Todd Vanacore)P1 qualifying best at Runoffs 2024: 2:00.476 (Chip Romer)FF race best at Runoffs 2015: 2:03.383 (Rick Payne)FF race best at Runoffs 2016: 1:30.133 (Neil Verhagen)FF race best at Runoffs 2017: 1:44.524 (Jonathon Kotyk)FF race best at Runoffs 2018: 1:42.049 (Jonathon Kotyk)FF race best at Runoffs 2019: 2:20.474 (Jonathan Kotyk)FF race best at Runoffs 2020: 2:24.268 (Jeffrey Bartz)FF race best at Runoffs 2021: 1:55.676 (Jonathan Kotyk)FF race best at Runoffs 2022: 2:18.358 (Jonathan Kotyk)FF race best at Runoffs 2023: 2:00.583 (Jonathan Kotyk)FF race best at Runoffs 2024: 2:22.057 (Sebastian Mateo Naranjo)FF race best at Runoffs 2025: 2:25.541 (Calvin Kautz)FF race best at Runoffs 2026: 2:23.686 (Nathan Down)FF qualifying best at Runoffs 2015: 2:02.489 (Tim Kautz)FF qualifying best at Runoffs 2016: 1:29.213 (Neil Verhagen)FF qualifying best at Runoffs 2017: 1:44.601 (Zach Holden)FF qualifying best at Runoffs 2018: 1:41.612 (Jonathon Kotyk)FF qualifying best at Runoffs 2019: 1:59.563 (Tyler O'Connor)FF qualifying best at Runoffs 2020: 2:22.916 (Simon Sikes)FF qualifying best at Runoffs 2021: 1:44.359 (Jonathan Kotyk)FF qualifying best at Runoffs 2022: 1:59.215 (Jonathan Kotyk)FF qualifying best at Runoffs 2023: 1:59.249 (Nolan Allaer)FF qualifying best at Runoffs 2024: 2:22.552 (Calvin Kautz)FF qualifying best at Runoffs 2025: 2:24.905 (Jonathan Kotyk)FF qualifying best at Runoffs 2026: 2:23.047 (David Ybarra)AS race best at Runoffs 2015: 2:02.922 (Andy McDermid)AS race best at Runoffs 2016: 1:33.424 (Edward Hosni)AS race best at Runoffs 2017: 1:51.507 (Bryan Long)AS race best at Runoffs 2018: 1:50.345 (John Heinricy)AS race best at Runoffs 2019: 2:03.900 (James Jost)AS race best at Runoffs 2020: 2:27.668 (Gregory Eaton)AS race best at Runoffs 2021: 1:50.606 (Gregory Eaton)AS race best at Runoffs 2022: 2:04.578 (Gregory Eaton)AS race best at Runoffs 2023: 2:04.120 (Gregory Eaton)AS race best at Runoffs 2024: 2:26.429 (Gregory Eaton)AS race best at Runoffs 2025: 2:29.232 (Gregory Eaton)AS race best at Runoffs 2026: 2:28.471 (Andrew McDermid)AS qualifying best at Runoffs 2015: 2:01.746 (Tom Sloe)AS qualifying best at Runoffs 2016: 1:30.651 (Tom Sloe)AS qualifying best at Runoffs 2017: 1:45.220 (James Jost)AS qualifying best at Runoffs 2018: 1:47.782 (Andrew McDermid)AS qualifying best at Runoffs 2019: 2:02.938 (Gregory Eaton)AS qualifying best at Runoffs 2020: 2:27.045 (Gregory Eaton)AS qualifying best at Runoffs 2021: 1:50.427 (Drew Cattell)AS qualifying best at Runoffs 2022: 2:02.162 (Kurt Rezzetano)AS qualifying best at Runoffs 2023: 2:03.082 (Daniel Richardson)AS qualifying best at Runoffs 2024: 2:26.578 (Gregory Eaton)AS qualifying best at Runoffs 2025: 2:26.792 (Andrew McDermid)AS qualifying best at Runoffs 2026: 2:26.911 (Andrew McDermid)F5 race best at Runoffs 2015: 2:03.298 (Matthew Strand)F5 race best at Runoffs 2016: 1:29.853 (Steven Thompson)F5 race best at Runoffs 2017: 1:42.860 (Wiley Clinton McMahan)F5 race best at Runoffs 2018: 1:42.491 (David Lapham)F5 race best at Runoffs 2019: 1:57.572 (Wiley Mcmahan)F5 race best at Runoffs 2020: 2:21.391 (James Weida)F5 race best at Runoffs 2021: 1:43.140 (Sven de Vries)F5 race best at Runoffs 2022: 2:21.862 (Sven de Vries)F5 qualifying best at Runoffs 2015: 2:01.824 (W. Clint McMahan)F5 qualifying best at Runoffs 2016: 1:28.528 (Calvin Stewart)F5 qualifying best at Runoffs 2017: 1:43.136 (Wiley Clinton McMahan)F5 qualifying best at Runoffs 2018: 1:41.807 (Jeff Jorgenson)F5 qualifying best at Runoffs 2019: 1:57.361 (Wiley Mcmahan)F5 qualifying best at Runoffs 2020: 2:20.954 (Calvin Stewart)F5 qualifying best at Runoffs 2021: 1:42.619 (Ryan Mayfield)F5 qualifying best at Runoffs 2022: 1:57.689 (James Weida)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
P1FFASF5solid race · dashed qualifying · slower is lower
100%110%120%22 rule changes between Runoffs 2018 and Runoffs 201922 ▾30 rule changes between Runoffs 2019 and Runoffs 202030 ▾31 rule changes between Runoffs 2020 and Runoffs 202131 ▾18 rule changes between Runoffs 2021 and Runoffs 202218 ▾12 rule changes between Runoffs 2022 and Runoffs 202312 ▾19 rule changes between Runoffs 2023 and Runoffs 202419 ▾15 rule changes between Runoffs 2024 and Runoffs 202515 ▾15 rule changes between Runoffs 2025 and Runoffs 202615 ▾P1 race best at Runoffs 2015: 100.0% of P1's (Gianpaolo Ciancimino)P1 race best at Runoffs 2016: 100.0% of P1's (Gianpaolo Ciancimino)P1 race best at Runoffs 2017: 100.0% of P1's (Jim Devenport)P1 race best at Runoffs 2018: 100.0% of P1's (Perry Richardson)P1 race best at Runoffs 2019: 100.0% of P1's (Todd Slusher)P1 race best at Runoffs 2020: 100.0% of P1's (James French)P1 race best at Runoffs 2021: 100.0% of P1's (Lee Alexander)P1 race best at Runoffs 2022: 100.0% of P1's (John Mcaleer)P1 race best at Runoffs 2023: 100.0% of P1's (Todd Vanacore)P1 race best at Runoffs 2024: 100.0% of P1's (Matt Romer)P1 qualifying best at Runoffs 2015: 100.0% of P1's (Jim Downing)P1 qualifying best at Runoffs 2016: 100.0% of P1's (James Devenport)P1 qualifying best at Runoffs 2017: 100.0% of P1's (Jim Devenport)P1 qualifying best at Runoffs 2018: 100.0% of P1's (Todd Slusher)P1 qualifying best at Runoffs 2019: 100.0% of P1's (Todd Slusher)P1 qualifying best at Runoffs 2020: 100.0% of P1's (James French)P1 qualifying best at Runoffs 2021: 100.0% of P1's (Lee Alexander)P1 qualifying best at Runoffs 2022: 100.0% of P1's (Todd Slusher)P1 qualifying best at Runoffs 2023: 100.0% of P1's (Todd Vanacore)P1 qualifying best at Runoffs 2024: 100.0% of P1's (Chip Romer)FF race best at Runoffs 2015: 112.4% of P1's (Rick Payne)FF race best at Runoffs 2016: 113.5% of P1's (Neil Verhagen)FF race best at Runoffs 2017: 114.2% of P1's (Jonathon Kotyk)FF race best at Runoffs 2018: 114.9% of P1's (Jonathon Kotyk)Off the chart: FF race best at Runoffs 2019: 135.7% of P1's (Jonathan Kotyk)FF race best at Runoffs 2020: 118.4% of P1's (Jeffrey Bartz)Off the chart: FF race best at Runoffs 2021: 129.6% of P1's (Jonathan Kotyk)FF race best at Runoffs 2022: 121.3% of P1's (Jonathan Kotyk)FF race best at Runoffs 2023: 115.6% of P1's (Jonathan Kotyk)FF race best at Runoffs 2024: 118.0% of P1's (Sebastian Mateo Naranjo)FF qualifying best at Runoffs 2015: 112.1% of P1's (Tim Kautz)FF qualifying best at Runoffs 2016: 115.4% of P1's (Neil Verhagen)FF qualifying best at Runoffs 2017: 115.2% of P1's (Zach Holden)FF qualifying best at Runoffs 2018: 115.8% of P1's (Jonathon Kotyk)FF qualifying best at Runoffs 2019: 116.4% of P1's (Tyler O'Connor)FF qualifying best at Runoffs 2020: 118.0% of P1's (Simon Sikes)FF qualifying best at Runoffs 2021: 117.2% of P1's (Jonathan Kotyk)FF qualifying best at Runoffs 2022: 117.3% of P1's (Jonathan Kotyk)FF qualifying best at Runoffs 2023: 116.2% of P1's (Nolan Allaer)FF qualifying best at Runoffs 2024: 118.3% of P1's (Calvin Kautz)AS race best at Runoffs 2015: 112.0% of P1's (Andy McDermid)AS race best at Runoffs 2016: 117.7% of P1's (Edward Hosni)AS race best at Runoffs 2017: 121.9% of P1's (Bryan Long)AS race best at Runoffs 2018: 124.3% of P1's (John Heinricy)AS race best at Runoffs 2019: 119.7% of P1's (James Jost)AS race best at Runoffs 2020: 121.2% of P1's (Gregory Eaton)AS race best at Runoffs 2021: 124.0% of P1's (Gregory Eaton)AS race best at Runoffs 2022: 109.2% of P1's (Gregory Eaton)AS race best at Runoffs 2023: 119.0% of P1's (Gregory Eaton)AS race best at Runoffs 2024: 121.6% of P1's (Gregory Eaton)AS qualifying best at Runoffs 2015: 111.5% of P1's (Tom Sloe)AS qualifying best at Runoffs 2016: 117.3% of P1's (Tom Sloe)AS qualifying best at Runoffs 2017: 115.9% of P1's (James Jost)AS qualifying best at Runoffs 2018: 122.9% of P1's (Andrew McDermid)AS qualifying best at Runoffs 2019: 119.7% of P1's (Gregory Eaton)AS qualifying best at Runoffs 2020: 121.4% of P1's (Gregory Eaton)AS qualifying best at Runoffs 2021: 124.1% of P1's (Drew Cattell)AS qualifying best at Runoffs 2022: 120.2% of P1's (Kurt Rezzetano)AS qualifying best at Runoffs 2023: 120.0% of P1's (Daniel Richardson)AS qualifying best at Runoffs 2024: 121.7% of P1's (Gregory Eaton)F5 race best at Runoffs 2015: 112.3% of P1's (Matthew Strand)F5 race best at Runoffs 2016: 113.2% of P1's (Steven Thompson)F5 race best at Runoffs 2017: 112.4% of P1's (Wiley Clinton McMahan)F5 race best at Runoffs 2018: 115.4% of P1's (David Lapham)F5 race best at Runoffs 2019: 113.6% of P1's (Wiley Mcmahan)F5 race best at Runoffs 2020: 116.0% of P1's (James Weida)F5 race best at Runoffs 2021: 115.6% of P1's (Sven de Vries)F5 race best at Runoffs 2022: 124.3% of P1's (Sven de Vries)F5 qualifying best at Runoffs 2015: 111.5% of P1's (W. Clint McMahan)F5 qualifying best at Runoffs 2016: 114.5% of P1's (Calvin Stewart)F5 qualifying best at Runoffs 2017: 113.6% of P1's (Wiley Clinton McMahan)F5 qualifying best at Runoffs 2018: 116.1% of P1's (Jeff Jorgenson)F5 qualifying best at Runoffs 2019: 114.3% of P1's (Wiley Mcmahan)F5 qualifying best at Runoffs 2020: 116.4% of P1's (Calvin Stewart)F5 qualifying best at Runoffs 2021: 115.3% of P1's (Ryan Mayfield)F5 qualifying best at Runoffs 2022: 115.8% of P1's (James Weida)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
P1FFASF5solid race · dashed qualifying · each class's best lap as a share of P1's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker
EventP1FFASF5
Qual best Race best Trap Qual best Race best Trap vs P1 % of P1 Qual best Race best Trap vs P1 % of P1 Qual best Race best Trap vs P1 % of P1 
Road America Runoffs 20262026-09-282:23.047David Ybarra · fastest of 20 · top 5 within 1.4s-1.858s (-1.28%)2:23.686Nathan Down · fastest of 20 · top 5 within 1.6s-1.855s (-1.27%)138.9Tazio Stefanelli+0.5 mph (+0.3%)2:26.911Andrew McDermid · fastest of 8 · top 5 within 3.4s+0.119s (+0.08%)2:28.471Andrew McDermid · fastest of 8 · top 5 within 2.4s-0.761s (-0.51%)151.0Andrew McDermid-0.6 mph (-0.4%)
15 rule changes (FF: 2, AS: 13)2 cars added · 2 engine · 2 tyres & wheels · 2 weight · 1 induction · 1 suspension & brakes · 3 wording · 2 other · AS Camaro 16+ Spec Line: 1LE front splitter kit permitted, belt tensioner and motor mount parts allowed, spark plug position defined. · AS class adds Pirelli P Zero Trofeo Track as permitted tyre option for competition. · AS class rear trailing arms no longer required to maintain stock length, only to locate rear axle. · AS Ford Mustang GT 4.6L 4-valve regains allowance, minimum weight 3200 lbs. · AS Ford Mustang Coupe GT 05-14 Gen3 Coyote minimum weight increases from 3100 to 3400 lbs. · FF Kent 1600 compression ratio calculation parameters reorganized: bore size and valve protrusion limits moved to separate subsections for clarity. · AS GM LM7 5.3L must use full prep Holley carburetor as described in 9.1.6.D.c.1, not specifically 4776. · AS EFI engine build sheets add dry sump, header, camshaft, and timing chain tensioner options for LS, LT1, Ford, and Mopar engines. · AS LT1 Camaro engine build sheet added with full specs; LT1 weight 3200 lbs, GTO tire to 275, Mustang weight to 3525 lbs, oil catch tanks now required. · AS Spec Lines reorganized for 2026; detailed chassis, engine, weight, wheelbase, tire and brake specifications moved to main rules and engine build sheets. · AS GM LM7 5.3L gains Edelbrock 71187 intake manifold, MSD 6014 ignition box, Holly 4776 carb option under full prep spec line. · AS Ford Mustang and Mercury Capri with Restricted Prep engines get 61 mm restrictor, down from 64 mm. · FF clarifies alternative tire eligibility: homologated 1989 or earlier with rocker or outboard suspension all four corners; push-rod/pull-rod cars may seek approval. · AS Ford Mustang GT 94-04 Restricted Prep Engine now permits Ford Motorsport M-6250-F303 camshaft. · AS Cadillac CTS-V 04-07 Restricted Prep minimum weight drops to 3400 lbs.showhide
  • AS 2016+ Camaro Spec Line Full Prep #39646otheraddedAS Camaro 16+ Spec Line: 1LE front splitter kit permitted, belt tensioner and motor mount parts allowed, spark plug position defined.
  • AS Consideration of Pirelli P Zero Trofeo Track for AS Competition #40495tyres & wheelsaddedtyres & wheelsAS class adds Pirelli P Zero Trofeo Track as permitted tyre option for competition.
  • AS Change in 9.1.6.D.4.d.5 in Suspension Mounting Points #40094suspension & brakesfastersuspension & brakesAS class rear trailing arms no longer required to maintain stock length, only to locate rear axle.
  • AS Re-Add 4.6L 4v 96-04 Mustang Cobra #40239cars addedaddedAS Ford Mustang GT 4.6L 4-valve regains allowance, minimum weight 3200 lbs.
  • AS Errors and Omissions #40532weightslowerweightAS Ford Mustang Coupe GT 05-14 Gen3 Coyote minimum weight increases from 3100 to 3400 lbs.
  • FF Clarification in FF Kent 1600 Compression Ratio Paragraph #40293wordingwordingFF Kent 1600 compression ratio calculation parameters reorganized: bore size and valve protrusion limits moved to separate subsections for clarity.
  • AS Clarification for LM7 Holley Carburetor #40167wordingwordingAS GM LM7 5.3L must use full prep Holley carburetor as described in 9.1.6.D.c.1, not specifically 4776.
  • AS Header Information Update for EFI Engine Build Sheets #39886engineaddedengineAS EFI engine build sheets add dry sump, header, camshaft, and timing chain tensioner options for LS, LT1, Ford, and Mopar engines.
  • AS Errors and Omissions #39933otherfasterAS LT1 Camaro engine build sheet added with full specs; LT1 weight 3200 lbs, GTO tire to 275, Mustang weight to 3525 lbs, oil catch tanks now required.
  • AS Re-Organization of AS Spec lines for 2026 #39887wordingwordingAS Spec Lines reorganized for 2026; detailed chassis, engine, weight, wheelbase, tire and brake specifications moved to main rules and engine build sheets.
  • AS Edelbrock manifold (& timing kit) to Chevy LS Spec Lines Request #39055cars addedaddedAS GM LM7 5.3L gains Edelbrock 71187 intake manifold, MSD 6014 ignition box, Holly 4776 carb option under full prep spec line.
  • AS Restrictor Plate Change for Gen 2 Ford Coyote Engine #39501inductionslowerinductionAS Ford Mustang and Mercury Capri with Restricted Prep engines get 61 mm restrictor, down from 64 mm.
  • FF Formula F Alternative Tire Rule Proposed Clarifications #39281tyres & wheelsaddedtyres & wheelsFF clarifies alternative tire eligibility: homologated 1989 or earlier with rocker or outboard suspension all four corners; push-rod/pull-rod cars may seek approval.
  • AS 1994 Mustang Spec Line Request #39104engineaddedengineAS Ford Mustang GT 94-04 Restricted Prep Engine now permits Ford Motorsport M-6250-F303 camshaft.
  • AS Cadillac CTS-V BOP Weight Change #38640weight -50 lbsfasterweightAS Cadillac CTS-V 04-07 Restricted Prep minimum weight drops to 3400 lbs.
Road America Runoffs 20252025-09-292:24.905Jonathan Kotyk · fastest of 17 · top 5 within 1.1s+2.353s (+1.65%)2:25.541Calvin Kautz · fastest of 16 · top 5 within 0.5s+3.484s (+2.45%)138.4Tazio Stefanelli-2.3 mph (-1.6%)2:26.792Andrew McDermid · fastest of 11 · top 5 within 3.9s+0.214s (+0.15%)2:29.232Gregory Eaton · fastest of 10 · top 5 within 4.0s+2.803s (+1.91%)151.5Andrew McDermid+1.9 mph (+1.3%)
15 rule changes (FF: 4, AS: 11)4 engine · 2 tyres & wheels · 2 weight · 1 cars added · 1 induction · 3 wording · 2 other · AS Ford Mustang GT 5.0 2018- minimum weight reduced to 3525 lbs. · AS Ford Mustang GT 05-14 Restricted Prep Engine gains additional gear ratio option: 3.66, 2.43, 1.69, 1.32, 1.00, .65. · AS Ford Mustang GT 5.0L 15-17 flat plate restrictor reduces from 67mm to 64mm. · AS LS1/LS6 intakes added for 5.3L truck engine: part numbers 12561269 and 88894095. · FF adds rocker arm and outboard suspension cars option to use Hoosier bias ply slicks or VFF tyres; clarifies mixing rules. · AS Flotek head value seat cutting dimensions figure updated for consistency. · AS class notes cleaned: fuel cell and ECM specifications removed from multiple Camaro, Firebird, Challenger and Mustang variants. · AS removes 'Any ECM maybe used' note from five Cadillac and Chevrolet/Pontiac V8 Restricted Prep models. · FF adds alternative tire options for older cars with rocker arm or outboard suspension: bias ply slicks or VFF radials. · AS Ford Mustang and Cobra Coyote engine restrictor increases to 80mm from 67mm or 64mm. · AS Mustang GT 05-14 Restricted loses 300 lbs engine; 15-17 and 2018+ models lose 61mm and 60mm restrictors respectively. · AS class: multiple American muscle cars gain additional allowed gear ratio options across model years and prep levels. · AS LS-engine cars gain ECU freedom: CTS-V, Camaro, Firebird (70–02) and Camaro SS may use any ECM. · FF and FC sequential gearbox weight penalty reduces from 25 lbs to 10 lbs minimum weight addition. · FF Honda Fit pistons: OEM 0.25mm oversize PN 13020-RB7-Z00 or Fast Forward PN FF800-110 now both allowed; standard diameter 73.240mm (2.8835 inches), minimum weight 198.0g.showhide
  • AS RE: Previous Letter 37695 Update #38245weight -75 lbsfasterweightAS Ford Mustang GT 5.0 2018- minimum weight reduced to 3525 lbs.
  • AS Errors and Omissions #38234otheraddedAS Ford Mustang GT 05-14 Restricted Prep Engine gains additional gear ratio option: 3.66, 2.43, 1.69, 1.32, 1.00, .65.
  • AS Errors and Omission #38055inductionslowerinductionAS Ford Mustang GT 5.0L 15-17 flat plate restrictor reduces from 67mm to 64mm.
  • AS Request to Add LS1/LS6 Intakes for 5.3L Truck Engine EnO #38197cars addedaddedAS LS1/LS6 intakes added for 5.3L truck engine: part numbers 12561269 and 88894095.
  • FF Page 228, FF tire rule 9.1.1.10.e #38251tyres & wheelsaddedtyres & wheelsFF adds rocker arm and outboard suspension cars option to use Hoosier bias ply slicks or VFF tyres; clarifies mixing rules.
  • AS Flotek Head Plunge Cut Inconsistencies #37502wordingwordingAS Flotek head value seat cutting dimensions figure updated for consistency.
  • AS Notes clean up #37693wordingwordingAS class notes cleaned: fuel cell and ECM specifications removed from multiple Camaro, Firebird, Challenger and Mustang variants.
  • AS Race memo #37902wordingwordingAS removes 'Any ECM maybe used' note from five Cadillac and Chevrolet/Pontiac V8 Restricted Prep models.
  • FF Formula F Proposal to Invite Older Cars Via a Tire Rule Change #37802tyres & wheelsaddedtyres & wheelsFF adds alternative tire options for older cars with rocker arm or outboard suspension: bias ply slicks or VFF radials.
  • AS Increase Coyote Engine Restrictor to 80mm #36177enginefasterengineAS Ford Mustang and Cobra Coyote engine restrictor increases to 80mm from 67mm or 64mm.
  • AS Performance Pack for 2015+ Mustang #36867enginefasterengineAS Mustang GT 05-14 Restricted loses 300 lbs engine; 15-17 and 2018+ models lose 61mm and 60mm restrictors respectively.
  • AS Gear Ratios #37131otheraddedAS class: multiple American muscle cars gain additional allowed gear ratio options across model years and prep levels.
  • AS ECU specs for LS engine #37208engineaddedengineAS LS-engine cars gain ECU freedom: CTS-V, Camaro, Firebird (70–02) and Camaro SS may use any ECM.
  • FF Change FF/FC Weight with Sequential Gearbox #36651weightfasterweightFF and FC sequential gearbox weight penalty reduces from 25 lbs to 10 lbs minimum weight addition.
  • FF Alternative Oversize Honda Fit Pistons #37064engineaddedengineFF Honda Fit pistons: OEM 0.25mm oversize PN 13020-RB7-Z00 or Fast Forward PN FF800-110 now both allowed; standard diameter 73.240mm (2.8835 inches), minimum weight 198.0g.
Road America Runoffs 20242024-10-012:00.476Chip Romer · fastest of 12 · top 5 within 1.5s-0.625s (-0.52%)2:00.418Matt Romer · fastest of 9 · top 5 within 2.1s-1.452s (-1.19%)168.3Jason Miller+8.7 mph (+5.4%)2:22.552Calvin Kautz · fastest of 13 · top 5 within 1.1s-0.364s (-0.25%)2:22.057Sebastian Mateo Naranjo · fastest of 13 · top 5 within 0.6s-2.211s (-1.53%)140.7Calvin Kautz+2.6 mph (+1.9%)+21.639squal +22.076s118.0%qual 118.3%2:26.578Gregory Eaton · fastest of 18 · top 5 within 2.6s-0.467s (-0.32%)2:26.429Gregory Eaton · fastest of 18 · top 5 within 2.5s-1.239s (-0.84%)149.6Gregory Eaton+0.4 mph (+0.3%)+26.011squal +26.102s121.6%qual 121.7%
19 rule changes (P1: 6, FF: 2, AS: 11)5 cars added · 2 engine · 2 weight · 1 tyres & wheels · 5 wording · 4 other · FF EGR blanking plate rule clarified: VTEC activation valve must be retained and functioning, no modifications permitted. · AS Mustang GT 05-14 Restricted Prep and 2018- gain alternate transmission ratio options. · AS adds 2018-23 Ford Mustang GT 5.0L at 3600 lbs, 275 tire, 60mm restrictor, optional Brembo front brakes. · AS Chevrolet Camaro 1LE (2016-) added with 3600 lbs minimum weight, 275 tires, 60mm restrictor, 345/338mm brakes. · AS Chevrolet/Pontiac Camaro & Firebird 82–92 5.7L LS1 classified: 3200 lbs, 13.1×1.27 disc brakes, 17 in max wheel, 65 mm restrictor, SLP intake lid permitted. · AS Chevrolet Camaro, Firebird, and Ford Mustang now permit Flo Tek cylinder heads in multiple generations. · P1 engine approval process wording clarified; unspecified engines need case-by-case Board review. · AS Camaro, Firebird 93-02 and GTO 04-06 add approved LS1 connecting rod part numbers to Notes. · AS Cadillac CTS-V, Chevy Camaro SS V8, Dodge Challenger, Ford Mustang GT 5.0L, Pontiac GTO allowed 11" wheels until 3/1/25. · Chevrolet Camaro, Pontiac Firebird 70–81 Full Prep classified in AS at 3400–3600 lbs with 108.0 wheelbase, specific head castings, and suspension modifications permitted. · AS class adds fuel cell location notes to multiple Cadillac, Chevrolet, Dodge and Ford models: cells within 24 inches of standard tank. · Chevrolet Camaro 6th gen Full Prep added to AS class at 3400 lbs base or 3600 lbs with built engine. · AS class: Ford Mustang GT 05-14 Restricted prep added; Cadillac CTS-V 04-07 to 3450 lbs; Camaro/Firebird variants reconfigured with weight and notes changes; Dodge Challenger 08-20 restrictor 76mm to 80mm; Ford Mustang variants updated wei… · P1 removes redundant effective date language from ECU stall prohibition rule. · P1 Honda K20A-FD2 engine terminology corrected from 'spec' to proper series designation; FIA certification documentation requirement removed. · FF Honda Fit gains Fast Forward oversize piston ring option PN FF800-100 as alternative to Riken or Nippon. · P1 Engine Table line H restrictor grows to 32 mm, weight rises to 1450 lbs; line I restrictor to 31 mm, weight to 1475 lbs. · P1 Group CN Honda K20A-FD2 removes engine modification restrictions; CRB may add intake restrictor if needed.showhide
  • FF Update to FF EGR Blanking Plate Rule #36633wordingwordingFF EGR blanking plate rule clarified: VTEC activation valve must be retained and functioning, no modifications permitted.
  • AS Mustang transmission ratios #36662otheraddedAS Mustang GT 05-14 Restricted Prep and 2018- gain alternate transmission ratio options.
  • AS Request for Classification of 2018-2023 mustang In #35764cars addedaddedAS adds 2018-23 Ford Mustang GT 5.0L at 3600 lbs, 275 tire, 60mm restrictor, optional Brembo front brakes.
  • AS 6th gen Camaro limited prep #35733cars addedaddedAS Chevrolet Camaro 1LE (2016-) added with 3600 lbs minimum weight, 275 tires, 60mm restrictor, 345/338mm brakes.
  • AS Chevrolet/Pontiac Camaro & Firebird (82-92) 5.7L V8 LS1 Alum BLK #35825cars addedaddedAS Chevrolet/Pontiac Camaro & Firebird 82–92 5.7L LS1 classified: 3200 lbs, 13.1×1.27 disc brakes, 17 in max wheel, 65 mm restrictor, SLP intake lid permitted.
  • AS Full Prep Head #35891engineaddedengineAS Chevrolet Camaro, Firebird, and Ford Mustang now permit Flo Tek cylinder heads in multiple generations.
  • P1 Update GCR section 9.1.8.B.J.7 #35907wordingwordingP1 engine approval process wording clarified; unspecified engines need case-by-case Board review.
  • AS Restricted Prep Aftermarket Parts Request #35682otheraddedAS Camaro, Firebird 93-02 and GTO 04-06 add approved LS1 connecting rod part numbers to Notes.
  • AS Allowance of 11 #35824tyres & wheelsfastertyres & wheelsAS Cadillac CTS-V, Chevy Camaro SS V8, Dodge Challenger, Ford Mustang GT 5.0L, Pontiac GTO allowed 11" wheels until 3/1/25.
  • AS Request to Classify 1970-1981 Camaro and Firebird in AS #33659cars addedaddedChevrolet Camaro, Pontiac Firebird 70–81 Full Prep classified in AS at 3400–3600 lbs with 108.0 wheelbase, specific head castings, and suspension modifications permitted.
  • AS Fuel Cell 12 #34194otheraddedAS class adds fuel cell location notes to multiple Cadillac, Chevrolet, Dodge and Ford models: cells within 24 inches of standard tank.
  • AS Please Classify the 6th Gen Into AS. #35448cars addedaddedChevrolet Camaro 6th gen Full Prep added to AS class at 3400 lbs base or 3600 lbs with built engine.
  • AS spec lines #35713otherunclearAS class: Ford Mustang GT 05-14 Restricted prep added; Cadillac CTS-V 04-07 to 3450 lbs; Camaro/Firebird variants reconfigured with weight and notes changes; Dodge Challenger 08-20 restrictor 76mm to 80mm; Ford Mustang variants updated wei…
  • P1 Remove redundant effective date language in GCR 9.1.8.B.J.4 #35693wordingwordingP1 removes redundant effective date language from ECU stall prohibition rule.
  • P1 Correct engine series terminology #35694wordingwordingP1 Honda K20A-FD2 engine terminology corrected from 'spec' to proper series designation; FIA certification documentation requirement removed.
  • FF Honda Fit Oversize Piston Rings #35305engineaddedengineFF Honda Fit gains Fast Forward oversize piston ring option PN FF800-100 as alternative to Riken or Nippon.
  • P1 Please correct omitted punctuation #34890weight
  • P1 Adjust restrictors and weights for Engine Table lines H and I #35229weightslowerweightP1 Engine Table line H restrictor grows to 32 mm, weight rises to 1450 lbs; line I restrictor to 31 mm, weight to 1475 lbs.
  • P1 Revise Group CN Honda K20A-FD2 Spec Line #35337wordingunclearP1 Group CN Honda K20A-FD2 removes engine modification restrictions; CRB may add intake restrictor if needed.
Virginia International Raceway Runoffs 20232023-09-231:42.602Todd Vanacore · fastest of 10 · top 5 within 0.9s+1.001s (+0.99%)1:44.329Todd Vanacore · fastest of 9 · top 5 within 0.7s-9.766s (-8.56%)158.5Jason Miller+1.2 mph (+0.8%)1:59.249Nolan Allaer · fastest of 8 · top 5 within 2.8s+0.034s (+0.03%)2:00.583Jonathan Kotyk · fastest of 8 · top 5 within 0.4s-17.775s (-12.85%)138.4Calvin Kautz+0.1 mph (+0.1%)+16.254squal +16.647s115.6%qual 116.2%2:03.082Daniel Richardson · fastest of 11 · top 5 within 2.2s+0.920s (+0.75%)2:04.120Gregory Eaton · fastest of 9 · top 5 within 3.0s-0.458s (-0.37%)154.6James Jost+3.7 mph (+2.5%)+19.791squal +20.480s119.0%qual 120.0%
12 rule changes (P1: 7, FF: 1, AS: 4)2 aero · 2 engine · 1 tyres & wheels · 6 wording · 1 other · AS crate motor part number specification clarified; both CT400 P/N-19370604 and 19370604 engine assemblies permitted for GM vehicles. · AS Ford Mustang GT 5.0L (15-17) Restricted maximum wheel diameter increases to 19.0 inches. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front upper control arms; SPC-66045 spec part removed. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 now allows alternate front brake calipers with adaptor brackets for component compatibility. · P1 SIR testing: vehicle deemed compliant if it stalls within 3 seconds of the stall test. · P1 intake restrictor rule clarified: flat plate, venturi, or Single Inlet Restrictor required; all intake air must pass through. · P1 ducted air rule clarified: top-exit ducted air must pass through heat exchanger, except cockpit opening and engine bay vents. · P1 aero height limit, front/rear overhang, and cockpit dimensions corrected to metric-inch equivalents. · FF Honda Fit engine adds Fast Forward part number alternatives for intake, exhaust, oil system, and scavenge pump components. · P1 suspension covers must have symmetrical upper and lower surfaces, no airfoil cross-sections or angled downforce. · P1 aerodynamic devices may not extend more than 1cm below lower surfaces rear of front axle; body panels covering suspension must not be airfoil-shaped or create downforce. · P1 forced induction prohibited: turbocharging and supercharging not allowed.showhide
  • AS Crate Motor Part Numbers #32944wordingwordingAS crate motor part number specification clarified; both CT400 P/N-19370604 and 19370604 engine assemblies permitted for GM vehicles.
  • AS Request wheel size change #33007tyres & wheelsfastertyres & wheelsAS Ford Mustang GT 5.0L (15-17) Restricted maximum wheel diameter increases to 19.0 inches.
  • AS Alternative Upper Front Control Arms for Dodge Challenger #33352wordingwordingAS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front upper control arms; SPC-66045 spec part removed.
  • AS Front Brake Caliper Adapters for Dodge Challenger #33353otherotherAS Dodge Challenger 5.7L/6.1L/6.4L V8 now allows alternate front brake calipers with adaptor brackets for component compatibility.
  • P1 SIR Testing #34354wordingwordingP1 SIR testing: vehicle deemed compliant if it stalls within 3 seconds of the stall test.
  • P1 E&O Single Inlet Restrictor abbreviation, etc. #34369wordingwordingP1 intake restrictor rule clarified: flat plate, venturi, or Single Inlet Restrictor required; all intake air must pass through.
  • P1 E&O Clean up ducted air provision #34410wordingwordingP1 ducted air rule clarified: top-exit ducted air must pass through heat exchanger, except cockpit opening and engine bay vents.
  • P1 E&O - Correct dimensional equivalents #34018wordingwordingP1 aero height limit, front/rear overhang, and cockpit dimensions corrected to metric-inch equivalents.
  • FF Add Fast Forward Part Numbers for Honda Fit Engine #33752engineaddedengineFF Honda Fit engine adds Fast Forward part number alternatives for intake, exhaust, oil system, and scavenge pump components.
  • P1 November 2022 Rules Clarification for Suspension Covers #33615aerosloweraeroP1 suspension covers must have symmetrical upper and lower surfaces, no airfoil cross-sections or angled downforce.
  • P1 Clarify body panel coverage of suspension components #33318aeroaeroP1 aerodynamic devices may not extend more than 1cm below lower surfaces rear of front axle; body panels covering suspension must not be airfoil-shaped or create downforce.
  • P1 E&O clarification regarding forced induction #33123engineremovedengineP1 forced induction prohibited: turbocharging and supercharging not allowed.
Virginia International Raceway Runoffs 20222022-09-241:41.601Todd Slusher · fastest of 9 · top 5 within 2.3s-1.073s (-1.05%)1:54.095John Mcaleer · fastest of 9 · top 5 within 1.4s+10.597s (+10.24%)157.2Jason Miller+1.3 mph (+0.8%)1:59.215Jonathan Kotyk · fastest of 13 · top 5 within 1.2s-0.348s (-0.29%)2:18.358Jonathan Kotyk · fastest of 12 · top 5 within 2.4s-2.116s (-1.51%)138.3Tim Kautz+2.2 mph (+1.6%)+24.263squal +17.614s121.3%qual 117.3%2:02.162Kurt Rezzetano · fastest of 13 · top 5 within 2.3s-0.776s (-0.63%)2:04.578Gregory Eaton · fastest of 11 · top 5 within 2.9s+0.678s (+0.55%)150.9James Jost-3.0 mph (-2.0%)+10.483squal +20.561s109.2%qual 120.2%1:57.689James Weida · fastest of 11 · top 5 within 3.9s+0.328s (+0.28%)2:21.862Sven de Vries · fastest of 10 · top 5 within 14.3s+24.290s (+20.66%)142.9Calvin Stewart+0.1 mph (+0.1%)+27.767squal +16.088s124.3%qual 115.8%
18 rule changes (P1: 3, AS: 9, F5: 6)4 engine · 2 cars added · 2 weight · 1 tyres & wheels · 6 wording · 3 other · AS adds Hoosier W2 wet tyre option alongside R7, R6, WET/H20. · AS Dodge Challenger 08-20 gains two transmission ratio options: 2.97–0.50 or 2.26–0.63. · F500 Rotax 493 and 593 intake boots: removed Moto Tassinari V3124-873B-2 from 493/593 non-HO allowance, added Moto Tassinari V3120-794A-2 option for non-HO. · F500 Rotax engines now permit Ingi Tech Sparker ignition DCP-CDI-P2 as alternate ECU. · P1 motorcycle-based engines with individual throttle bodies must use flat plate intake restrictors within 4 inches of primary butterfly. · AS Cadillac CTS-V 6.0L V8 Restricted Prep removes 295 tire size 50 lb penalty. · F500 clarifies stepped diameter exhaust headers prohibited except at cylinder head flange area. · F500 Rotax 593 intake boot options clarified; oil injection pump removal now permitted. · P1 bodywork rules clarified: cycle fenders prohibited, side body minimum height at front axle centerline, air ducting for downforce banned. · F500 Majors and Runoffs cars must install AIM part #X47KPFSOLO2R0 data box mount for Solo or Solo 2. · SMG Long Tube Headers: Borla PN 17237 discontinued, approved alternatives American Racing MT3-05134300LSNC or Kooks PN 11312000. · AS Mercury Capri 79-86 removed as separate spec line, merged into Ford Mustang 79-93 spec line. · AS Spec Mustang SMG Restricted Prep removes 3.73 gear ratio and 355/300 brake disc sizes. · AS Camaro, Firebird, Mustang full prep engines: alternate GM and Ford Performance cylinder heads permitted regionally with Allstar restrictor ALL26180. · F5 cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs. · P1 2-cycle 6-cylinder maximum displacement increases to 1725 cc, restrictor shrinks to 40mm, minimum weight drops to 1275 lbs. · AS Chevrolet/Pontiac Camaro & Firebird 93-02 gains BMR AA004 or UMI 2310 adjustable front upper control arms. · AS Pontiac GTO 04-06 Restricted Prep minimum weight rises: LS1 to 3300 lbs, LS2 to 3350 lbs on 295 tires.showhide
  • AS Request to add Hoosier W2 #33031tyres & wheelsaddedtyres & wheelsAS adds Hoosier W2 wet tyre option alongside R7, R6, WET/H20.
  • AS correction of Dodge Challenger specification line #33151cars addedaddedAS Dodge Challenger 08-20 gains two transmission ratio options: 2.97–0.50 or 2.26–0.63.
  • F5 Intake Boots Correction #33028wordingwordingF500 Rotax 493 and 593 intake boots: removed Moto Tassinari V3124-873B-2 from 493/593 non-HO allowance, added Moto Tassinari V3120-794A-2 option for non-HO.
  • F5 Ensure availability of ECU for Rotax engines #32695engineaddedengineF500 Rotax engines now permit Ingi Tech Sparker ignition DCP-CDI-P2 as alternate ECU.
  • P1 Clarify authorization to use flat plate intake restrictor #32964engineaddedengineP1 motorcycle-based engines with individual throttle bodies must use flat plate intake restrictors within 4 inches of primary butterfly.
  • AS Request CTS-V Spec Line Error Correction #30242weightfasterweightAS Cadillac CTS-V 6.0L V8 Restricted Prep removes 295 tire size 50 lb penalty.
  • F5 Clarify stepped exhaust header references #32743wordingwordingF500 clarifies stepped diameter exhaust headers prohibited except at cylinder head flange area.
  • F5 593 carb boot availability and oil pump clarification #32527wordingwordingF500 Rotax 593 intake boot options clarified; oil injection pump removal now permitted.
  • P1 E&O Clarification of Bodywork Rules #32468wordingwordingP1 bodywork rules clarified: cycle fenders prohibited, side body minimum height at front axle centerline, air ducting for downforce banned.
  • F5 E&O class name #32194otheraddedF500 Majors and Runoffs cars must install AIM part #X47KPFSOLO2R0 data box mount for Solo or Solo 2.
  • AS Proposed Revisions to SCCA GCR 2021 Appendix M, Part 3 #30295wordingwordingSMG Long Tube Headers: Borla PN 17237 discontinued, approved alternatives American Racing MT3-05134300LSNC or Kooks PN 11312000.
  • AS specification line consolidation and correction #31846cars addedremovedcars addedAS Mercury Capri 79-86 removed as separate spec line, merged into Ford Mustang 79-93 spec line.
  • AS correction of SMG specification line #31847wordingremovedAS Spec Mustang SMG Restricted Prep removes 3.73 gear ratio and 355/300 brake disc sizes.
  • AS Alternate cylinder heads for full prep engine builds - Evaluation #31851engineaddedengineAS Camaro, Firebird, Mustang full prep engines: alternate GM and Ford Performance cylinder heads permitted regionally with Allstar restrictor ALL26180.
  • F5 Data Box Mounting Plate #31638otheraddedF5 cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs.
  • P1 Displacement & Weight Change Request for 2-Cycle 6 Cylinder #31609enginefasterengineP1 2-cycle 6-cylinder maximum displacement increases to 1725 cc, restrictor shrinks to 40mm, minimum weight drops to 1275 lbs.
  • AS Request for adjustable Front Upper Control Arms on 4th Gen F-Body #30457otheraddedAS Chevrolet/Pontiac Camaro & Firebird 93-02 gains BMR AA004 or UMI 2310 adjustable front upper control arms.
  • AS Request Pontiac GTO tire size change #30881weightslowerweightAS Pontiac GTO 04-06 Restricted Prep minimum weight rises: LS1 to 3300 lbs, LS2 to 3350 lbs on 295 tires.
Indianapolis Motor Speedway Runoffs 20212021-09-251:29.011Lee Alexander · fastest of 13 · top 5 within 2.5s-1.783s (-1.96%)1:29.225Lee Alexander · fastest of 12 · top 5 within 3.5s-2.274s (-2.49%)160.1Jason Miller1:44.359Jonathan Kotyk · fastest of 24 · top 5 within 1.1s-0.242s (-0.23%)1:55.676Jonathan Kotyk · fastest of 23 · top 5 within 1.8s+11.152s (+10.67%)141.6Nicholas Sheppard+26.451squal +15.348s129.6%qual 117.2%1:50.427Drew Cattell · fastest of 31 · top 5 within 1.9s+5.207s (+4.95%)1:50.606Gregory Eaton · fastest of 28 · top 5 within 1.7s-0.901s (-0.81%)153.8James Jost+21.381squal +21.416s124.0%qual 124.1%1:42.619Ryan Mayfield · fastest of 22 · top 5 within 1.6s-0.517s (-0.50%)1:43.140Sven de Vries · fastest of 20 · top 5 within 1.7s+0.280s (+0.27%)144.4James Weida+13.915squal +13.608s115.6%qual 115.3%
31 rule changes (P1: 11, FF: 3, AS: 14, F5: 3)8 cars added · 4 engine · 3 weight · 14 wording · 2 other · P1 creates separate spec lines H and I for 2000cc and 2300cc engines at 1400 and 1445 lbs minimum weight respectively. · P1 Staudacher may run 950 lbs minimum weight with 38.5mm flat plate intake restrictor, removing prior weight-linked restrictor rule. · F5 clarifies mechanical shifting only; throttle-cut and flat-shifter devices permitted if driver retains full control. · F5 single-seat open-wheel cars: rigid suspension becomes limited suspension in class definition. · P1 adds 1355cc motorcycle-based engine line C at 1075 lbs minimum weight, no restrictor required. · AS Cadillac CTS-V 6.0L LS6 removes 295-tire 50 lb penalty. · AS consolidates seven SN95 Mustang '94-'04 spec lines into three unified lines by model year and engine. · AS Camaro/Firebird LT1 and LS1 transmission changed to TUET1 6362; Mustang GT 4.6L/5spd to TUKT16901, loses 300 lbs. · AS Camaro & Firebird and Mustang GT gear ratio specifications restored with alternate sets permitted. · AS Camaro, Firebird, Mustang, and Capri all gain 50 lbs minimum weight across seven model year variants. · F500 Rotax 593 HO engine now permitted; 875 lbs minimum weight, MA0242SP1020A or MA0242SP1063A restrictor, specific intake boots and piston required. · P1 cockpit opening section allows tonneau covers to meet minimum dimensions; wording clarified on equipment attachment. · P1 Staudacher 1005cc homologated before 1-1-2014 may run 38.5mm flat plate intake restrictor at 950 lbs minimum weight. · P1 Spec Line C: FPIR not required at 1150 lbs, 1355cc max may run without FPIR at 1075 lbs. Spec Line G: up to 2000cc runs 30mm SIR at 1400 lbs, 2300cc runs 30mm SIR at 1445 lbs. · P1 classes B, C, D maximum valves per cylinder set to 4, previously unspecified. · FF block relief permitted only as needed to fit an allowed crankshaft. · P1 Spec Line A clarifies carburetor induction only, one per cylinder, balance tubes not allowed. · P1 Spec Line H notes clarify peripheral port or bridgeport allowed; wording only. · AS Mustang 4.6L 5spd gains cold air intake freedom; 5.0L 6spd now requires 56mm flat plate restrictor. · AS CTS-V 5.7L LS6 and 6.0L LS2 may use Driveshaft Shop P/N GMCTSV2-C carbon fiber driveshaft. · AS Chevrolet Camaro SS V8 6.2L Restricted Prep model years extended from 10–13 to 10–15. · P1 Elan DP02-spec Mazda MZR sealed engine option removed effective 3/1/2021. · P1 Engine Table Spec Lines C and G change 'inlet restrictor' to 'intake restrictor' terminology. · AS Ford Mustang GT 5.0L 15-17 Restricted added to Spec Line with 3600 lbs minimum weight, 55mm restrictor, 18×10 wheels, 295 tires. · AS underhood bracing on stock hoods, trunks, and rear decks may be modified or removed. · AS Cadillac CTS-V 04-07 with 295 tire drops to 3450 lbs; Camaro SS V8 10-13 and Challenger 08-20 specs removed. · AS Camaro & Firebird (93-02) and Mustang GT (05-14) specifications restored with weight minimums 3250–3500 and 3350–3600 lbs respectively. · AS Dodge Challenger gains 6.1L and 6.4L V8 options; 5.7L weight rises to 3500 lbs on 295 tyres, 3600 on 315 tyres; compression to 10.9:1 max. · AS Camaro & Firebird (93-02) and Ford Mustang Coupe GT (05-14) spec lines consolidated; Camaro/Firebird now allows both LT1 and LS1 engines; Mustang now allows both 4.6L 3-valve and 5.0L 4-valve engines with restrictor. · FF class cylinder head now permits optional coolant bleed line pipe thread fitting to swirl tower. · FF Honda LC1 ECU supplied by HPD is permitted effective 12/1/2020 with HPD lambda sensor.showhide
  • P1 Move 2000cc and 2300cc engine options to individual spec lines #31012cars addedaddedP1 creates separate spec lines H and I for 2000cc and 2300cc engines at 1400 and 1445 lbs minimum weight respectively.
  • P1 E&O Spec Line B notes #31095wordingwordingP1 Staudacher may run 950 lbs minimum weight with 38.5mm flat plate intake restrictor, removing prior weight-linked restrictor rule.
  • F5 Clarify allowable assisted shifting systems #30871wordingwordingF5 clarifies mechanical shifting only; throttle-cut and flat-shifter devices permitted if driver retains full control.
  • F5 Request to correct terminology #30976wordingwordingF5 single-seat open-wheel cars: rigid suspension becomes limited suspension in class definition.
  • P1 Add 1355cc spec line #30890cars addedaddedP1 adds 1355cc motorcycle-based engine line C at 1075 lbs minimum weight, no restrictor required.
  • AS Request CTS-V Spec Line Error Correction #30242weightfasterweightAS Cadillac CTS-V 6.0L LS6 removes 295-tire 50 lb penalty.
  • AS Request to consolidate SN95 Mustang '94-'04 Mustang spec lines #30428wordingwordingAS consolidates seven SN95 Mustang '94-'04 spec lines into three unified lines by model year and engine.
  • AS American Sedan Transmission Rule Change Request #30595enginefasterengineAS Camaro/Firebird LT1 and LS1 transmission changed to TUET1 6362; Mustang GT 4.6L/5spd to TUKT16901, loses 300 lbs.
  • AS Correction to specifications inadvertently deleted #30691wordingwordingAS Camaro & Firebird and Mustang GT gear ratio specifications restored with alternate sets permitted.
  • AS weight adjustments #30700weight +50 lbsslowerweightAS Camaro, Firebird, Mustang, and Capri all gain 50 lbs minimum weight across seven model year variants.
  • F5 Request to Allow Rotax 593 HO Engine #30712cars addedaddedF500 Rotax 593 HO engine now permitted; 875 lbs minimum weight, MA0242SP1020A or MA0242SP1063A restrictor, specific intake boots and piston required.
  • P1 E&O tonneau cover provision in cockpit opening section #30458wordingwordingP1 cockpit opening section allows tonneau covers to meet minimum dimensions; wording clarified on equipment attachment.
  • P1 Update Spec Line B Notes #30498wordingwordingP1 Staudacher 1005cc homologated before 1-1-2014 may run 38.5mm flat plate intake restrictor at 950 lbs minimum weight.
  • P1 Update Spec Lines C and G notes #30499wordingwordingP1 Spec Line C: FPIR not required at 1150 lbs, 1355cc max may run without FPIR at 1075 lbs. Spec Line G: up to 2000cc runs 30mm SIR at 1400 lbs, 2300cc runs 30mm SIR at 1445 lbs.
  • P1 E&O Maximum Valves Per Cylinder #30559engineengineP1 classes B, C, D maximum valves per cylinder set to 4, previously unspecified.
  • FF Kent crankshaft clarification #30426wordingwordingFF block relief permitted only as needed to fit an allowed crankshaft.
  • P1 Clean up Spec Line A notes section #30424wordingwordingP1 Spec Line A clarifies carburetor induction only, one per cylinder, balance tubes not allowed.
  • P1 Clean up Spec Line H notes section #30425wordingwordingP1 Spec Line H notes clarify peripheral port or bridgeport allowed; wording only.
  • AS AS Mustang LP 4.6 3V Classification Transmission Request #29886enginefasterengineAS Mustang 4.6L 5spd gains cold air intake freedom; 5.0L 6spd now requires 56mm flat plate restrictor.
  • AS Request CF driveshaft on CTS-V for durability improvement #30117otheraddedAS CTS-V 5.7L LS6 and 6.0L LS2 may use Driveshaft Shop P/N GMCTSV2-C carbon fiber driveshaft.
  • AS Adjustment to model years of 5th generation RP Camaro #30348cars addedaddedAS Chevrolet Camaro SS V8 6.2L Restricted Prep model years extended from 10–13 to 10–15.
  • P1 DP02 Sealed 2ltr Engine Option #30038engineremovedengineP1 Elan DP02-spec Mazda MZR sealed engine option removed effective 3/1/2021.
  • P1 E&O restrictor terminology #30285wordingwordingP1 Engine Table Spec Lines C and G change 'inlet restrictor' to 'intake restrictor' terminology.
  • AS Request for 2015 -2017 Ford Mustang Spec Line #29514cars addedaddedAS Ford Mustang GT 5.0L 15-17 Restricted added to Spec Line with 3600 lbs minimum weight, 55mm restrictor, 18×10 wheels, 295 tires.
  • AS Request Trunk lid / Rear Hatch clarification #29591wordingwordingAS underhood bracing on stock hoods, trunks, and rear decks may be modified or removed.
  • AS Common Weight for CTS-V Tire #29759weightfasterweightAS Cadillac CTS-V 04-07 with 295 tire drops to 3450 lbs; Camaro SS V8 10-13 and Challenger 08-20 specs removed.
  • AS Correction to specifications inadvertently deleted #30041cars addedaddedAS Camaro & Firebird (93-02) and Mustang GT (05-14) specifications restored with weight minimums 3250–3500 and 3350–3600 lbs respectively.
  • AS Request Additional Engine Options for Dodge Challenger Spec Line #29543cars addedaddedAS Dodge Challenger gains 6.1L and 6.4L V8 options; 5.7L weight rises to 3500 lbs on 295 tyres, 3600 on 315 tyres; compression to 10.9:1 max.
  • AS Rule simplification spec line communization #29824cars addedcars addedAS Camaro & Firebird (93-02) and Ford Mustang Coupe GT (05-14) spec lines consolidated; Camaro/Firebird now allows both LT1 and LS1 engines; Mustang now allows both 4.6L 3-valve and 5.0L 4-valve engines with restrictor.
  • FF Allow Optional Coolant Bleed Line to Correct a Known Problem #29673otheraddedFF class cylinder head now permits optional coolant bleed line pipe thread fitting to swirl tower.
  • FF Clarification regarding Honda LC1 ECU implementation date #29684wordingwordingFF Honda LC1 ECU supplied by HPD is permitted effective 12/1/2020 with HPD lambda sensor.
Road America Runoffs 20202020-10-022:01.101James French · fastest of 18 · top 5 within 1.1s2:01.870James French · fastest of 17 · top 5 within 1.8s159.7David Locke2:22.916Simon Sikes · fastest of 14 · top 5 within 1.6s2:24.268Jeffrey Bartz · fastest of 14 · top 5 within 0.4s138.1Jeffrey Bartz+22.398squal +21.815s118.4%qual 118.0%2:27.045Gregory Eaton · fastest of 18 · top 5 within 0.6s2:27.668Gregory Eaton · fastest of 15 · top 5 within 1.5s149.2Gregory Eaton+25.798squal +25.944s121.2%qual 121.4%2:20.954Calvin Stewart · fastest of 16 · top 5 within 1.8s2:21.391James Weida · fastest of 14 · top 5 within 1.5s143.2Aaron Ellis+19.521squal +19.853s116.0%qual 116.4%
30 rule changes (P1: 4, FF: 4, AS: 16, F5: 6)8 engine · 2 cars added · 2 induction · 2 weight · 1 aero · 1 removed · 1 suspension & brakes · 1 tyres & wheels · 11 wording · 1 other · F500 Suzuki GSXR600 engine years extended from 2003-2013 to 2003-2019. · AS Dodge Challenger 5.7L V8 now requires iron block instead of aluminum, compression to 10.5:1 max, intake valve 12.7 mm, exhaust 12.3 mm, intake timing 188 degrees, exhaust timing 205 degrees. · AS Dodge Challenger 08-14 rear spoiler: 1GL20RXF replaced with 1GL20TZZAB; 82211606 still permitted. · FF Honda LC1 ECU implementation date clarified to pending, contingent on SCCA receiving sufficient support materials. · AS class pursuing specified list of eligible tires; list details unclear from text provided. · AS class tire eligibility list under development; no specifications changed yet. · AS Coyote Mustang restrictor plate under review for 2021; no change effective yet. · AS Restricted Prep 4.6 3V now permits conversion to 2 valve configuration. · AS Ford Mustang Coupe GT 4.6L 3V Restricted Prep now permits Ford Performance camshaft kit P/N M-6550-3V. · 2010-2014 Camaro remains classified in AS; no specification changes. · AS class cylinder head supplier discontinuation; replacement option pending for 2021 season. · AS Mustang, Capri, Camaro, and Firebird maximum brake rotor diameter increased from 12.2 to 13.1 inches. · unclear · F5 request to adjust external jetting device cockpit control denied; no rule change made. · F5 driver adjustable carburettor mixture: refer to separate Fastrack letter #28359 for ruling. · F5 cockpit adjustment request response published in Fastrack letter 28359. · P1 intake manifolds unrestricted unless engine requires flat plate restrictor; no plenums or balance pipes on restricted individual runner manifolds. · FF Kent Engine alternator becomes optional instead of not required. · FF permits HPD LC1 ECU with lambda sensor; E1 ECU no longer supported but existing units may continue. · FF rain tyres now allow Hoosier W3 Radial 185/60R13 front and 205/60R13 rear. · AS rear trailing arms may be replaced with tubular arms maintaining stock length and axle location purpose only. · AS Ford and GM full prep cars get increased weight reduction from 150 to 200 lbs. · 05-10 Ford Mustang Coupe GT 4.6L OHC classified AS with 3200 lbs minimum weight, HR cam permitted. · 10-15 Camaro Full Prep classified AS with 3400 lbs base weight, 3700 lbs over 313 CID, specific head castings and Edelbrock heads permitted. · P1 sealed 2.0L Elan DP02-spec Mazda option removal date extended from 1/1/2020 to 1/1/2021. · F500 Honda CBR600RR, Suzuki GSXR600, Yamaha R6 restrictor reduced to 28mm from 29mm. · P1 sealed 2.0 MZR engine removed effective 1/1/2020; competitors may run it under Spec Line G. · P1 Spec Line F: Restricted 2.0L Group becomes CN-spec Honda K20A-FD2, 2000cc, 1400 lbs minimum.showhide
  • F5 Request to Update Suzuki Engine Years for F500 #29453engineaddedengineF500 Suzuki GSXR600 engine years extended from 2003-2013 to 2003-2019.
  • AS Dodge Challenger AS Spec Line Clarification #28698engineslowerengineAS Dodge Challenger 5.7L V8 now requires iron block instead of aluminum, compression to 10.5:1 max, intake valve 12.7 mm, exhaust 12.3 mm, intake timing 188 degrees, exhaust timing 205 degrees.
  • AS Dodge Challenger AS Spec Line Clarification #2 #28699aeroaeroAS Dodge Challenger 08-14 rear spoiler: 1GL20RXF replaced with 1GL20TZZAB; 82211606 still permitted.
  • FF Clarification regarding Honda LC1 ECU implementation #29135wordingwordingFF Honda LC1 ECU implementation date clarified to pending, contingent on SCCA receiving sufficient support materials.
  • AS Support for R-Type Specification Tires #27450wordingunclearAS class pursuing specified list of eligible tires; list details unclear from text provided.
  • AS Spec Tire Request #27519wordingunclearAS class tire eligibility list under development; no specifications changed yet.
  • AS Restrictor Plate Change for RP 2011+ Mustang with Coyote Engine #27675wordingunclearAS Coyote Mustang restrictor plate under review for 2021; no change effective yet.
  • AS 2005-2009 Restricted Prep 4.6 3V #27908engineaddedengineAS Restricted Prep 4.6 3V now permits conversion to 2 valve configuration.
  • AS Request for 2005-2009 Restricted Prep 4.6 3V Parts #27909engineaddedengineAS Ford Mustang Coupe GT 4.6L 3V Restricted Prep now permits Ford Performance camshaft kit P/N M-6550-3V.
  • AS Request for Full Preparation Classification for 2010-2014 Camaro #28030wordingunclear2010-2014 Camaro remains classified in AS; no specification changes.
  • AS Cylinder Heads #28696wordingunclearAS class cylinder head supplier discontinuation; replacement option pending for 2021 season.
  • AS Request for Max Rotor Diameter Change #28748otherfasterAS Mustang, Capri, Camaro, and Firebird maximum brake rotor diameter increased from 12.2 to 13.1 inches.
  • AS Request increase rotor diameter #28797wordingunclearunclear
  • F5 Request for Cockpit Adjustment of External Jetting Devices #28359wordingunclearF5 request to adjust external jetting device cockpit control denied; no rule change made.
  • F5 Two Stroke Motors (reply to #28359 WDYT) #28816engine
  • F5 Re letter requesting driver adjustable carb mixture #28840wordingunclearF5 driver adjustable carburettor mixture: refer to separate Fastrack letter #28359 for ruling.
  • F5 #28359 WDYT Request for Cockpit Adjustment #28875wordingunclearF5 cockpit adjustment request response published in Fastrack letter 28359.
  • AS weight adjustments for 2020 season #28785weight -50 lbs
  • P1 E&O minimum weights and intake manifolds #28731inductioninductionP1 intake manifolds unrestricted unless engine requires flat plate restrictor; no plenums or balance pipes on restricted individual runner manifolds.
  • FF E&O FF Kent Engine alternator language #28204engineaddedengineFF Kent Engine alternator becomes optional instead of not required.
  • FF Honda Racing HPD low cost ECU proposal #27563engineaddedengineFF permits HPD LC1 ECU with lambda sensor; E1 ECU no longer supported but existing units may continue.
  • FF Update rain tire designation #28443tyres & wheelsaddedtyres & wheelsFF rain tyres now allow Hoosier W3 Radial 185/60R13 front and 205/60R13 rear.
  • AS Rear Trailing Arms #28007suspension & brakesaddedsuspension & brakesAS rear trailing arms may be replaced with tubular arms maintaining stock length and axle location purpose only.
  • AS Weight reduction for cars running iron heads #28010weightfasterweightAS Ford and GM full prep cars get increased weight reduction from 150 to 200 lbs.
  • AS 05-10 Mustang with HR cam classification #28226cars addedadded05-10 Ford Mustang Coupe GT 4.6L OHC classified AS with 3200 lbs minimum weight, HR cam permitted.
  • AS 10-15 Camaro Full Prep classification #28227cars addedadded10-15 Camaro Full Prep classified AS with 3400 lbs base weight, 3700 lbs over 313 CID, specific head castings and Edelbrock heads permitted.
  • P1 Extend date for removing sealed DP02-spec 2.0L option #28046wordingunclearP1 sealed 2.0L Elan DP02-spec Mazda option removal date extended from 1/1/2020 to 1/1/2021.
  • F5 Change 600cc restrictor size #27883inductionslowerinductionF500 Honda CBR600RR, Suzuki GSXR600, Yamaha R6 restrictor reduced to 28mm from 29mm.
  • P1 Remove sealed DP02-spec 2.0 MZR spec #26753removedremovedP1 sealed 2.0 MZR engine removed effective 1/1/2020; competitors may run it under Spec Line G.
  • P1 Update Revised Spec Line F #27745engineengineP1 Spec Line F: Restricted 2.0L Group becomes CN-spec Honda K20A-FD2, 2000cc, 1400 lbs minimum.
Virginia International Raceway Runoffs 20192019-10-051:42.674Todd Slusher · fastest of 14 · top 5 within 1.5s1:43.498Todd Slusher · fastest of 13 · top 5 within 1.0s155.9Jim Devenport1:59.563Tyler O'Connor · fastest of 14 · top 5 within 1.4s2:20.474Jonathan Kotyk · fastest of 14 · top 5 within 6.3s136.2Derek Ketchie+36.976squal +16.889s135.7%qual 116.4%2:02.938Gregory Eaton · fastest of 17 · top 5 within 0.8s2:03.900James Jost · fastest of 16 · top 5 within 2.1s153.9James Jost+20.402squal +20.264s119.7%qual 119.7%1:57.361Wiley Mcmahan · fastest of 15 · top 5 within 3.8s1:57.572Wiley Mcmahan · fastest of 15 · top 5 within 4.0s142.8Eric McRee+14.074squal +14.687s113.6%qual 114.3%
22 rule changes (P1: 14, FF: 3, AS: 4, F5: 1)3 cars added · 2 weight · 1 aero · 1 engine · 14 wording · 1 other · AS Spec Mustang (SMG) added as Restricted Prep class. · F500 Honda CBR600RR, Suzuki GSXR600, and Yamaha R6 minimum weights increase to 900 lbs. · AS class ride height minimum clarified: five inches measured at rocker panel, excluding seams and stock effects. · P1 traction control prohibited. · P1 permits mechanical, solenoid, and air-shifters; prohibits electronic pre-selection and multi-wheel power. · P1 minimum bodywork height rule moved and restated with new 115cm aerodynamic part height limit. · P1 consolidates fender louver rules into one section; removes duplicate allowance for louvers and clarifies brake and engine air ducts are permitted. · AS Ford Mustang 79-93 non-Cobra drops 100 lbs to 3150; over 313 CID Cobra drops 100 lbs to 3450. · P1 anti-intrusion panels now allowed anywhere on chassis sides instead of specified locations. · P1 bodywork wording clarified: comfort and safety for driver and passenger or driver only. · P1 Engine Table reference cleaned up; no performance change. · P1 Mazda Renesis Rotary engine spec line removed from Engine Table. · P1 Staudacher and Honda K20A-FD2 engine table wording clarified; no performance change. · P1 closed cockpit single-seat cars remain prohibited; rule moved from subsection J.5 to B.4. · AS adds Spec Mustang SMG classification with 107.1 wheelbase, 3.73 gears, 355mm front and 300mm rear brakes. · FF Honda Fit cylinder honing increased to 73.315mm and oversize pistons PN 13020-RB7-Z00 now permitted with matching ring packs. · FF intake manifold thermal wrap now permitted if easily removable for inspection; no coating allowed. · FF clarifies coolant and oil catch tank capacity requirements: coolant minimum one U.S. pint, oil minimum one U.S. quart per system. · P1 engine table reference corrected from 'above' to 'below'; ETC/FBW/DBW throttle wording clarified on sensor and fail-safe requirements. · P1 removes TIR inlet restrictor option; deletes requirement for single turbo/supercharger unit with single restrictor. · P1 CN-spec Honda K20A-FD2 clarified: stock OEM parts required, no machining allowed. · P1 engine rules correct grammar and remove head designs from specification table.showhide
  • AS Request to add SMG to 9.1.6.B.1 AS Intent #27140cars addedaddedAS Spec Mustang (SMG) added as Restricted Prep class.
  • F5 Request for Weight Increase for Motorcycle Powered Cars #27214weight +25 lbsslowerweightF500 Honda CBR600RR, Suzuki GSXR600, and Yamaha R6 minimum weights increase to 900 lbs.
  • AS Request Ride Height Clarification #26598wordingwordingAS class ride height minimum clarified: five inches measured at rocker panel, excluding seams and stock effects.
  • P1 E&O Transmissions #27098wordingwordingP1 traction control prohibited.
  • P1 E&O Transmissions #27005otheraddedP1 permits mechanical, solenoid, and air-shifters; prohibits electronic pre-selection and multi-wheel power.
  • P1 Move minimum height provision to #27031wordingwordingP1 minimum bodywork height rule moved and restated with new 115cm aerodynamic part height limit.
  • P1 Remove duplicative fender louver provision #27033wordingwordingP1 consolidates fender louver rules into one section; removes duplicate allowance for louvers and clarifies brake and engine air ducts are permitted.
  • AS Request to Revert to 2017 Weights #25885weightfasterweightAS Ford Mustang 79-93 non-Cobra drops 100 lbs to 3150; over 313 CID Cobra drops 100 lbs to 3450.
  • P1 Missing word E&O #26919wordingwordingP1 anti-intrusion panels now allowed anywhere on chassis sides instead of specified locations.
  • P1 E&O correction to GCR 9.1.8.C.C. #26927wordingwordingP1 bodywork wording clarified: comfort and safety for driver and passenger or driver only.
  • P1 Clean up reference to engine table #26648wordingwordingP1 Engine Table reference cleaned up; no performance change.
  • P1 Remove redundant spec line #26692cars addedremovedcars addedP1 Mazda Renesis Rotary engine spec line removed from Engine Table.
  • P1 Clean Up Engine Table Language #26590wordingwordingP1 Staudacher and Honda K20A-FD2 engine table wording clarified; no performance change.
  • P1 Move single-seat closed cockpit provision to #26376wordingwordingP1 closed cockpit single-seat cars remain prohibited; rule moved from subsection J.5 to B.4.
  • AS SMG Mustang eligibility in American sedan #26224cars addedaddedAS adds Spec Mustang SMG classification with 107.1 wheelbase, 3.73 gears, 355mm front and 300mm rear brakes.
  • FF Request for Oversize Honda Fit Pistons #25810enginefasterengineFF Honda Fit cylinder honing increased to 73.315mm and oversize pistons PN 13020-RB7-Z00 now permitted with matching ring packs.
  • FF Heat Shield - Fit Intake #26102aeroaddedaeroFF intake manifold thermal wrap now permitted if easily removable for inspection; no coating allowed.
  • FF Request catch cans/tanks clarification #26158wordingwordingFF clarifies coolant and oil catch tank capacity requirements: coolant minimum one U.S. pint, oil minimum one U.S. quart per system.
  • P1 Correct errors in GCR section 9.1.8.C.J #26144wordingwordingP1 engine table reference corrected from 'above' to 'below'; ETC/FBW/DBW throttle wording clarified on sensor and fail-safe requirements.
  • P1 Remove redundant inlet restrictor provisions #25877wordingwordingP1 removes TIR inlet restrictor option; deletes requirement for single turbo/supercharger unit with single restrictor.
  • P1 Clarify Honda K20A-FD2 parts requirement #25949wordingwordingP1 CN-spec Honda K20A-FD2 clarified: stock OEM parts required, no machining allowed.
  • P1 Correct GCR section 9.1.8.C.J errors #25966wordingwordingP1 engine rules correct grammar and remove head designs from specification table.
Sonoma Raceway Runoffs 20182018-10-101:27.714Todd Slusher · fastest of 19 · top 5 within 2.1s1:28.786Perry Richardson · fastest of 19 · top 5 within 0.9s144.0Johnnie Crean1:41.612Jonathon Kotyk · fastest of 22 · top 5 within 1.7s1:42.049Jonathon Kotyk · fastest of 22 · top 5 within 1.3s115.7Denny Renfrow+13.263squal +13.898s114.9%qual 115.8%1:47.782Andrew McDermid · fastest of 12 · top 5 within 1.9s1:50.345John Heinricy · fastest of 10 · top 5 within 2.3s105.0Kevin Fandozzi+21.559squal +20.068s124.3%qual 122.9%1:41.807Jeff Jorgenson · fastest of 5 · top 5 within 6.6s1:42.491David Lapham · fastest of 5 · top 5 within 9.5s113.3David Lapham+13.705squal +14.093s115.4%qual 116.1%
No rule changes on record between these events
Indianapolis Motor Speedway Runoffs 20172017-09-251:30.794Jim Devenport · fastest of 19 · top 5 within 2.8s1:31.499Jim Devenport · fastest of 16 · top 5 within 2.2s1:44.601Zach Holden · fastest of 36 · top 5 within 1.2s1:44.524Jonathon Kotyk · fastest of 36 · top 5 within 0.5s+13.025squal +13.807s114.2%qual 115.2%1:45.220James Jost · fastest of 29 · top 5 within 6.7s1:51.507Bryan Long · fastest of 28 · top 5 within 0.9s+20.008squal +14.426s121.9%qual 115.9%1:43.136Wiley Clinton McMahan · fastest of 38 · top 5 within 1.4s1:42.860Wiley Clinton McMahan · fastest of 37 · top 5 within 1.6s+11.361squal +12.342s112.4%qual 113.6%
No rule changes on record between these events
Mid-Ohio Sports Car Course Runoffs 20162016-09-191:17.308James Devenport · fastest of 14 · top 5 within 2.7s1:19.407Gianpaolo Ciancimino · fastest of 13 · top 5 within 1.8s1:29.213Neil Verhagen · fastest of 14 · top 5 within 2.1s1:30.133Neil Verhagen · fastest of 14 · top 5 within 1.4s+10.726squal +11.905s113.5%qual 115.4%1:30.651Tom Sloe · fastest of 22 · top 5 within 3.6s1:33.424Edward Hosni · fastest of 20 · top 5 within 1.0s+14.017squal +13.343s117.7%qual 117.3%1:28.528Calvin Stewart · fastest of 14 · top 5 within 3.9s1:29.853Steven Thompson · fastest of 12 · top 5 within 4.5s+10.446squal +11.220s113.2%qual 114.5%
No rule changes on record between these events
Daytona International Speedway Runoffs 20152015-09-211:49.219Jim Downing · fastest of 9 · top 5 within 2.2s1:49.792Gianpaolo Ciancimino · fastest of 10 · top 5 within 1.7s2:02.489Tim Kautz · fastest of 25 · top 5 within 1.1s2:03.383Rick Payne · fastest of 22 · top 5 within 0.8s+13.591squal +13.270s112.4%qual 112.1%2:01.746Tom Sloe · fastest of 22 · top 5 within 2.6s2:02.922Andy McDermid · fastest of 19 · top 5 within 2.2s+13.130squal +12.527s112.0%qual 111.5%2:01.824W. Clint McMahan · fastest of 16 · top 5 within 3.0s2:03.298Matthew Strand · fastest of 15 · top 5 within 4.9s+13.506squal +12.605s112.3%qual 111.5%

By track

TrackEvents Typical % of P1 Best Latest 
Road America4100.0%2 of 4 with P1100.0%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 P1's best on the same day: the weather and the day cancel out, so one figure compares across years where lap times cannot; a class that suits one track more than another still reads differently there. 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.