BoP Lab / Classes / 1D

1D vs BSpec vs AS pace at every track

Lap times across years say as much about the weather as the class. % of 1D is each class's best lap as a share of 1D'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)

1D×vsAS ×B-Spec +vsBSpec ×EP +FA +FC +FE2 +FF +FP +FV +FX +GT1 +GT2 +GTX +HP +P +P2 +SM +SMX +SRF3 +STL +STU +T1 +T2 +T3 +T4 +Show 49 inactive classes

Series Runoffs Super Tour Both

Reference · what % is measured against

Tracks · untick to narrow Auto Club Speedway Barber Motorsports Park Blackhawk Farms Raceway Buttonwillow Raceway Park Circuit of St. Louis (formerly Gateway Motorsports Circuit of the Americas Daytona International Speedway Grattan Raceway Hallett Motor Racing Circuit Homestead-Miami Speedway Indianapolis Motor Speedway Laguna Seca Michelin Raceway Road Atlanta Mid-Ohio Sports Car Course New Jersey Motorsports Park NOLA Motorsports Park Pacific Raceways Pittsburgh International Race Complex Portland International Raceway Road America Sebring International Raceway Sonoma Raceway Summit Point Raceway Thunderhill Raceway Park Virginia International Raceway Watkins Glen International Willow Springs Raceway World Wide Technology Raceway

1DBSpecASsolid race · dashed qualifying · slower is lower

	Event	1D			BSpec					AS
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs 1D	% of 1D	Qual best	Race best	Trap	vs 1D	% of 1D
	Road America Runoffs 20262026-09-28									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%)
13 rule changes (AS: 13)5 weight · 3 engine · 2 tyres & wheels · 1 induction · 1 removed · 1 othershowhide 2026-09-01 AS 2016+ Camaro Spec Line Full Prep #39646tyres & wheels 2026-09-01 AS Consideration of Pirelli P Zero Trofeo Track for AS Competition #40495tyres & wheels 2026-08-01 AS Change in 9.1.6.D.4.d.5 in Suspension Mounting Points #40094other 2026-08-01 AS Re-Add 4.6L 4v 96-04 Mustang Cobra #40239weight 2026-08-01 AS Errors and Omissions #40532weight 2026-06-01 AS Clarification for LM7 Holley Carburetor #40167engine 2026-04-01 AS Header Information Update for EFI Engine Build Sheets #39886engine 2026-04-01 AS Errors and Omissions #39933weight 2026-03-01 AS Re-Organization of AS Spec lines for 2026 #39887removed 2026-02-01 AS Edelbrock manifold (& timing kit) to Chevy LS Spec Lines Request #39055weight 2026-01-01 AS Restrictor Plate Change for Gen 2 Ford Coyote Engine #39501induction 2025-12-01 AS 1994 Mustang Spec Line Request #39104engine 2025-11-01 AS Cadillac CTS-V BOP Weight Change #38640weight -50 lbs
	Road America Runoffs 20252025-09-29									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%)
11 rule changes (AS: 11)5 engine · 3 weight · 2 induction · 1 othershowhide 2025-07-01 AS RE: Previous Letter 37695 Update #38245weight -75 lbs 2025-06-01 AS Errors and Omissions #38234engine 2025-05-01 AS Errors and Omission #38055induction 2025-05-01 AS Request to Add LS1/LS6 Intakes for 5.3L Truck Engine EnO #38197engine 2025-04-01 AS Flotek Head Plunge Cut Inconsistencies #37502other 2025-04-01 AS Notes clean up #37693weight 2025-03-01 AS Race memo #37902engine 2025-01-01 AS Increase Coyote Engine Restrictor to 80mm #36177induction 2025-01-01 AS Performance Pack for 2015+ Mustang #36867weight 2025-01-01 AS Gear Ratios #37131engine 2025-01-01 AS ECU specs for LS engine #37208engine
	Road America Runoffs 20242024-10-01									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%)
11 rule changes (AS: 11)6 cars added · 1 engine · 1 tyres & wheels · 3 othershowhide 2024-09-01 AS Mustang transmission ratios #36662engine 2024-06-01 AS Request for Classification of 2018-2023 mustang In #35764cars added 2024-05-01 AS 6th gen Camaro limited prep #35733cars added 2024-05-01 AS Chevrolet/Pontiac Camaro & Firebird (82-92) 5.7L V8 LS1 Alum BLK #35825cars added 2024-05-01 AS Full Prep Head #35891other 2024-04-01 AS Restricted Prep Aftermarket Parts Request #35682other 2024-04-01 AS Allowance of 11 #35824tyres & wheels 2024-03-01 AS Request to Classify 1970-1981 Camaro and Firebird in AS #33659cars added 2024-03-01 AS Fuel Cell 12 #34194other 2024-03-01 AS Please Classify the 6th Gen Into AS. #35448cars added 2024-03-01 AS spec lines #35713cars added
	Virginia International Raceway Runoffs 20232023-09-23									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%)
4 rule changes (AS: 4)2 engine · 1 suspension & brakes · 1 tyres & wheelsshowhide 2023-08-01 AS Crate Motor Part Numbers #32944engine 2023-08-01 AS Request wheel size change #33007tyres & wheels 2023-08-01 AS Alternative Upper Front Control Arms for Dodge Challenger #33352engine 2023-08-01 AS Front Brake Caliper Adapters for Dodge Challenger #33353suspension & brakes
	Virginia International Raceway Runoffs 20222022-09-24									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%)
9 rule changes (AS: 9)2 weight · 1 engine · 1 suspension & brakes · 2 wording · 3 othershowhide 2022-09-01 AS Request to add Hoosier W2 #33031other 2022-09-01 AS correction of Dodge Challenger specification line #33151wording 2022-07-01 AS Request CTS-V Spec Line Error Correction #30242weight 2022-01-01 AS Proposed Revisions to SCCA GCR 2021 Appendix M, Part 3 #30295other 2022-01-01 AS specification line consolidation and correction #31846wording 2022-01-01 AS correction of SMG specification line #31847suspension & brakes 2022-01-01 AS Alternate cylinder heads for full prep engine builds - Evaluation #31851engine 2021-10-01 AS Request for adjustable Front Upper Control Arms on 4th Gen F-Body #30457other 2021-10-01 AS Request Pontiac GTO tire size change #30881weight
	Indianapolis Motor Speedway Runoffs 20212021-09-25									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
14 rule changes (AS: 14)6 weight · 3 cars added · 3 engine · 2 wordingshowhide 2021-06-01 AS Request CTS-V Spec Line Error Correction #30242weight 2021-06-01 AS Request to consolidate SN95 Mustang '94-'04 Mustang spec lines #30428cars added 2021-06-01 AS American Sedan Transmission Rule Change Request #30595weight 2021-06-01 AS Correction to specifications inadvertently deleted #30691wording 2021-06-01 AS weight adjustments #30700weight +50 lbs 2021-03-01 AS AS Mustang LP 4.6 3V Classification Transmission Request #29886weight 2021-03-01 AS Request CF driveshaft on CTS-V for durability improvement #30117engine 2021-03-01 AS Adjustment to model years of 5th generation RP Camaro #30348engine 2021-01-01 AS Request for 2015 -2017 Ford Mustang Spec Line #29514cars added 2021-01-01 AS Request Trunk lid / Rear Hatch clarification #29591wording 2021-01-01 AS Common Weight for CTS-V Tire #29759weight 2021-01-01 AS Correction to specifications inadvertently deleted #30041cars added 2020-12-01 AS Request Additional Engine Options for Dodge Challenger Spec Line #29543engine 2020-12-01 AS Rule simplification spec line communization #29824weight
	Road America Runoffs 20202020-10-02									2:27.045Gregory Eaton · fastest of 18 · top 5 within 0.6s	2:27.668Gregory Eaton · fastest of 15 · top 5 within 1.5s	149.2Gregory Eaton
16 rule changes (AS: 16)3 engine · 2 cars added · 2 induction · 2 suspension & brakes · 2 tyres & wheels · 2 weight · 1 aero · 2 othershowhide 2020-08-01 AS Dodge Challenger AS Spec Line Clarification #28698induction 2020-08-01 AS Dodge Challenger AS Spec Line Clarification #2 #28699aero 2020-07-01 AS Support for R-Type Specification Tires #27450tyres & wheels 2020-07-01 AS Spec Tire Request #27519tyres & wheels 2020-07-01 AS Restrictor Plate Change for RP 2011+ Mustang with Coyote Engine #27675induction 2020-07-01 AS 2005-2009 Restricted Prep 4.6 3V #27908engine 2020-07-01 AS Request for 2005-2009 Restricted Prep 4.6 3V Parts #27909engine 2020-07-01 AS Request for Full Preparation Classification for 2010-2014 Camaro #28030other 2020-07-01 AS Cylinder Heads #28696engine 2020-07-01 AS Request for Max Rotor Diameter Change #28748suspension & brakes 2020-07-01 AS Request increase rotor diameter #28797other 2020-05-01 AS weight adjustments for 2020 season #28785weight -50 lbs 2020-02-01 AS Rear Trailing Arms #28007suspension & brakes 2020-02-01 AS Weight reduction for cars running iron heads #28010weight 2020-02-01 AS 05-10 Mustang with HR cam classification #28226cars added 2020-02-01 AS 10-15 Camaro Full Prep classification #28227cars added
	Virginia International Raceway Runoffs 20192019-10-05									2:02.938Gregory Eaton · fastest of 17 · top 5 within 0.8s	2:03.900James Jost · fastest of 16 · top 5 within 2.1s	153.9James Jost
4 rule changes (AS: 4)1 cars added · 1 suspension & brakes · 1 weight · 1 othershowhide 2019-10-01 AS Request to add SMG to 9.1.6.B.1 AS Intent #27140other 2019-08-01 AS Request Ride Height Clarification #26598suspension & brakes 2019-05-31 AS Request to Revert to 2017 Weights #25885weight 2019-02-01 AS SMG Mustang eligibility in American sedan #26224cars added
	Sonoma Raceway Runoffs 20182018-10-10									1:47.782Andrew McDermid · fastest of 12 · top 5 within 1.9s	1:50.345John Heinricy · fastest of 10 · top 5 within 2.3s	105.0Kevin Fandozzi
No rule changes on record between these events
	Indianapolis Motor Speedway Runoffs 20172017-09-25									1:45.220James Jost · fastest of 29 · top 5 within 6.7s	1:51.507Bryan Long · fastest of 28 · top 5 within 0.9s
No rule changes on record between these events
	Mid-Ohio Sports Car Course Runoffs 20162016-09-19									1:30.651Tom Sloe · fastest of 22 · top 5 within 3.6s	1:33.424Edward Hosni · fastest of 20 · top 5 within 1.0s
No rule changes on record between these events
	Daytona International Speedway Runoffs 20152015-09-21									2:01.746Tom Sloe · fastest of 22 · top 5 within 2.6s	2:02.922Andy McDermid · fastest of 19 · top 5 within 2.2s

By track

Track	Events	Typical % of 1D
Road America	4	0 of 4 with 1D
Virginia International Raceway	3	0 of 3 with 1D
Indianapolis Motor Speedway	2	0 of 2 with 1D
Daytona International Speedway	1	0 of 1 with 1D
Mid-Ohio Sports Car Course	1	0 of 1 with 1D
Sonoma Raceway	1	0 of 1 with 1D

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 1D'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.