BoP Lab / Classes / SRF

SRF vs FE2 pace at every track

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

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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 Pueblo Motorsports Park 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

Closest to the field: SRF 100.0% of SRF Cliff White, Daytona International Speedway Runoffs 2015 race

% of SRFLap times

SRFFE2solid race · dashed qualifying · slower is lower

SRFFE2solid race · dashed qualifying · each class's best lap as a share of SRF's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker

	Event	SRF			FE2
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs SRF	% of SRF
	Road America Runoffs 20262026-09-28				2:12.326Franklin Futrelle · fastest of 8 · top 5 within 1.9s-0.149s (-0.11%)	2:11.881Franklin Futrelle · fastest of 8 · top 5 within 1.6s-1.458s (-1.09%)	143.5Steve Whitston-5.5 mph (-3.7%)
4 rule changes (SRF: 3, FE2: 1)1 suspension & brakes · 3 othershowhide 2026-09-01 SRF GCR Rain/Brake Light Correction #40579suspension & brakes 2026-03-01 SRF SRF3 Spark Plugs #39899other 2025-10-01 FE2 FE & FE2 Bubble Tail #38978other 2025-10-01 SRF Add HD Oil Cooler #38979other
	Road America Runoffs 20252025-09-29				2:12.475Franklin Futrelle · fastest of 11 · top 5 within 1.4s+0.969s (+0.74%)	2:13.339Franklin Futrelle · fastest of 10 · top 5 within 0.6s+0.591s (+0.45%)	149.0Steve Whitston+3.7 mph (+2.6%)
3 rule changes (SRF: 2, FE2: 1)3 othershowhide 2025-04-01 FE2 Driver Safety & Comfort #37965other 2025-04-01 SRF Driver Safety & Comfort #37966other 2025-04-01 SRF Update SADEV transmission specs #37992other
	Road America Runoffs 20242024-10-01				2:11.506Porter Aiken · fastest of 18 · top 5 within 0.5s-1.300s (-0.98%)	2:12.748Porter Aiken · fastest of 17 · top 5 within 2.0s-0.523s (-0.39%)	145.3Porter Aiken+1.9 mph (+1.3%)
10 rule changes (SRF: 10)3 suspension & brakes · 3 tyres & wheels · 1 weight · 1 wording · 2 othershowhide 2024-10-01 SRF Update SRF3 Air Filter Rule #36681other 2024-10-01 SRF Update SRF Brake Rotor Thickness #36687suspension & brakes 2024-10-01 SRF Hoosier Tire Decal Placement #36739tyres & wheels 2024-09-01 SRF Protest Fee Clarification #36540wording 2024-09-01 SRF Update to Letter 36619 with new Hoosier Contingency Decal Info #36624tyres & wheels 2024-08-01 SRF Update Rain Tire Rule and Hoosier Decal Placement #36436tyres & wheels 2024-01-01 SRF Update SRF Rain / Brake Rule #34706suspension & brakes 2024-01-01 SRF Update SRF Brake Light Rule v1 #34853suspension & brakes 2024-01-01 SRF SRF / SRF3 Rule Updates #35268weight 2023-10-01 SRF SRF Radiator Rule Update #34805other
	Virginia International Raceway Runoffs 20232023-09-23				1:50.665Charles Russell Turner · fastest of 26 · top 5 within 2.3s-0.188s (-0.17%)	1:51.098Franklin Futrelle · fastest of 19 · top 5 within 1.4s-20.947s (-15.86%)	141.3Franklin Futrelle-0.6 mph (-0.4%)
3 rule changes (SRF: 3)2 tyres & wheels · 1 suspension & brakesshowhide 2023-06-01 SRF Hoosier SRF Wet Front Tire Rule Update #34189tyres & wheels 2023-05-01 SRF Update SRF Front W2 Rain Tire Part Number #34118tyres & wheels 2023-03-01 SRF Update SRF Brake Rule #33469suspension & brakes
	Virginia International Raceway Runoffs 20222022-09-24				1:50.853Charles Russell Turner · fastest of 25 · top 5 within 1.1s-0.209s (-0.19%)	2:12.045Jason Conzo · fastest of 22 · top 5 within 1.8s+19.891s (+17.74%)	141.9Eric Cruz-0.6 mph (-0.5%)
3 rule changes (SRF: 3)1 suspension & brakes · 1 tyres & wheels · 1 weightshowhide 2022-06-01 SRF SRF Tire Rule Update #32614tyres & wheels 2022-06-01 SRF Brake, seal, and air filter clarifications #32670suspension & brakes 2021-12-01 SRF Three Updates to SRF Rules #31523weight
	Indianapolis Motor Speedway Runoffs 20212021-09-25				1:36.395Max Grau · fastest of 28 · top 5 within 0.7s	1:36.655Max Grau · fastest of 28 · top 5 within 0.7s	146.2Gray Fowler
6 rule changes (SRF: 6)2 engine · 1 suspension & brakes · 1 tyres & wheels · 1 weight · 1 othershowhide 2021-08-01 SRF SRF Wet Tires #30849tyres & wheels 2021-08-01 SRF SADEV-SRF3 Transmission #30926other 2021-08-01 SRF SRF Update Maintenance, Repairs and Seals #30961engine 2021-06-01 SRF SRF3 Alternator Pulley #30684weight 2021-03-01 SRF Mandatory identification: #30223engine 2020-12-01 SRF SRF Shocks, Springs and Ride Height. #29688suspension & brakes
	Road America Runoffs 20202020-10-02				2:12.806Scott Rettich · fastest of 25 · top 5 within 0.6s	2:13.271Owen McAllister · fastest of 23 · top 5 within 0.7s	143.4Owen McAllister
7 rule changes (SRF: 5, FE2: 2)2 suspension & brakes · 2 weight · 1 tyres & wheels · 1 wording · 1 othershowhide 2020-09-01 FE2 FE/FE2 Oil Cooler #29293wording 2020-05-01 SRF SRF Bump Stop Correction #27019suspension & brakes 202-01-01 SRF SRF Rain / Brake Rule - BoD approved as follows #34958suspension & brakes 2019-12-01 FE2 FE / FE2 Update Rules #27624weight 2019-12-01 SRF SRF Tire Warmer Rule #27622tyres & wheels 2019-12-01 SRF SRF / SRF3 Nose Weight Reduction #27706weight 2019-12-01 SRF SRF / SRF3 Majors & Regional Class Updates #27723other
	Virginia International Raceway Runoffs 20192019-10-05				1:51.062Liam Snyder · fastest of 20 · top 5 within 1.3s	1:52.154Liam Snyder · fastest of 19 · top 5 within 0.7s	142.6Robert Vanman
1 rule change (SRF: 1)1 othershowhide 2019-07-01 SRF SRF Dash Windscreen Kit #27028other
	Sonoma Raceway Runoffs 20182018-10-10				1:35.040Flinn Lazier · fastest of 9 · top 5 within 1.5s	1:35.563Flinn Lazier · fastest of 9 · top 5 within 1.7s	126.8Scott Rettich
No rule changes on record between these events
	Indianapolis Motor Speedway Runoffs 20172017-09-25	1:51.573Thomas Kirchman · fastest of 50 · top 5 within 2.8s	1:53.769Todd Harris · fastest of 45 · top 5 within 0.2s
No rule changes on record between these events
	Mid-Ohio Sports Car Course Runoffs 20162016-09-19	1:37.344Mike Miserendino · fastest of 27 · top 5 within 0.8s	1:37.621Todd Harris · fastest of 27 · top 5 within 0.6s
No rule changes on record between these events
	Daytona International Speedway Runoffs 20152015-09-21	2:14.306Cliff White · fastest of 39 · top 5 within 1.2s	2:16.700Cliff White · fastest of 38 · top 5 within 0.5s

By track

Track	Events	Typical % of SRF	Best	Latest
Road America	4	0 of 4 with SRF
Virginia International Raceway	3	0 of 3 with SRF
Indianapolis Motor Speedway	2	100.0%1 of 2 with SRF	100.0%Runoffs 2017	100.0%Runoffs 2017
Daytona International Speedway	1	100.0%	100.0%Runoffs 2015	100.0%Runoffs 2015
Mid-Ohio Sports Car Course	1	100.0%	100.0%Runoffs 2016	100.0%Runoffs 2016
Sonoma Raceway	1	0 of 1 with SRF

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 SRF'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.