BoP Lab / Classes / SRF

SRF vs FM vs FE vs SM 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.

Class · click a class to switch, + to compare alongside (up to 4: remove one to add another)

ASB-SpecEPFAFCvsFE ×FE2FFvsFM ×FPFVFXGT1GT2GTXHPPP2vsSM ×SMXSRF×SRF3STLSTUT1T2T3T4Show 48 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 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 · FM 86.3% of SRF Joseph Burton-Harris, Daytona International Speedway Runoffs 2015 race · FE 87.1% of SRF Scott Rettich, Daytona International Speedway Runoffs 2015 race · SM 103.2% of SRF Michael Carter, Mid-Ohio Sports Car Course Runoffs 2016 race

% of SRFLap times

SRFFMFESMsolid race · dashed qualifying · slower is lower

SRFFMFESMsolid 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			FM					FE					SM
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs SRF	% of SRF	Qual best	Race best	Trap	vs SRF	% of SRF	Qual best	Race best	Trap	vs SRF	% of SRF
	Road America Runoffs 20262026-09-28														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%)
7 rule changes (SRF: 3, FE: 2, SM: 2)1 engine · 1 suspension & brakes · 1 wording · 4 othershowhide 2026-09-01 SRF GCR Rain/Brake Light Correction #40579suspension & brakes 2026-07-01 SM Rear Toe Link #40271other 2026-04-01 SM Part Number Change Request #39914wording 2026-03-01 SRF SRF3 Spark Plugs #39899other 2026-01-01 FE FE & FE2 Rule Updates #39484engine 2025-10-01 FE FE & FE2 Bubble Tail #38978other 2025-10-01 SRF Add HD Oil Cooler #38979other
	Road America Runoffs 20252025-09-29														2:43.111Bobby 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%)
8 rule changes (SRF: 2, FE: 2, SM: 4)1 suspension & brakes · 1 tyres & wheels · 1 weight · 1 wording · 4 othershowhide 2025-09-01 FE FE & FE2 Rule Updates #38901weight 2025-06-01 SM SMX Data Submission - Penalties #38248other 2025-06-01 SM SMX Penaly Clarification updated language #38337wording 2025-05-01 SM Clarify Tire Marking Regs #38005tyres & wheels 2025-04-01 SRF Driver Safety & Comfort #37966other 2025-04-01 SRF Update SADEV transmission specs #37992other 2024-12-01 FE Brake Line to A-Arm Covers #37110suspension & brakes 2024-12-01 SM E&O SMX Regs 9.1.7.1.D.5.u-.w #37070other
	Road America Runoffs 20242024-10-01														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%)
19 rule changes (SRF: 10, FE: 5, SM: 4)5 tyres & wheels · 4 suspension & brakes · 1 engine · 1 weight · 3 wording · 5 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 FE Protest Fee Clarification #36540wording 2024-09-01 FE Update on Letter 36620 with new Hoosier Contingency Decal Info #36625tyres & wheels 2024-09-01 SM SMX Camera Rule Correction #36496wording 2024-09-01 SM AIM ECU Protocol #36556engine 2024-09-01 SM OE versus OEM Definitons #36608other 2024-09-01 SM Shifter Bushing #36611suspension & brakes 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 FE Hoosier Tire Decal Placement #36435tyres & wheels 2024-08-01 SRF Update Rain Tire Rule and Hoosier Decal Placement #36436tyres & wheels 2024-01-01 FE Update FE Rain Light Rule #34707other 2024-01-01 FE FE/FE2 rule update #35269other 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														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%)
7 rule changes (SRF: 3, FE: 3, SM: 1)2 suspension & brakes · 2 tyres & wheels · 1 aero · 1 weight · 1 othershowhide 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 2023-04-01 FE Update FE SADEV Transmission Rule #33883other 2023-03-01 SRF Update SRF Brake Rule #33469suspension & brakes 2023-01-01 SM BOP for NB1 and NB2 #32309weight 2022-10-01 FE Brake bias adjuster clarification #33084suspension & brakes 2022-10-01 FE FE Front and Rear Wing Update & Clarification #33089aero
	Virginia International Raceway Runoffs 20222022-09-24														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%)
8 rule changes (SRF: 3, FE: 4, SM: 1)2 engine · 2 suspension & brakes · 2 tyres & wheels · 1 weight · 1 othershowhide 2022-09-01 FE Engine Heat Shield & Insulation #33019engine 2022-06-01 FE Update FE/FE2 Tire Rule #32613tyres & wheels 2022-06-01 FE Master cylinder clarification #32669engine 2022-06-01 SRF SRF Tire Rule Update #32614tyres & wheels 2022-06-01 SRF Brake, seal, and air filter clarifications #32670suspension & brakes 2022-04-01 SM Update GCR Section 9.1.7.3.A.1. #32217suspension & brakes 2021-12-01 FE Two FE2 Rule Updates #31524other 2021-12-01 SRF Three Updates to SRF Rules #31523weight
	Indianapolis Motor Speedway Runoffs 20212021-09-25														1:57.695Brian 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
11 rule changes (SRF: 6, FE: 4, SM: 1)2 engine · 2 suspension & brakes · 2 tyres & wheels · 1 weight · 1 wording · 3 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 2021-07-01 FE FE Tire Rule Changes #30754tyres & wheels 2021-07-01 FE Radiator Screens Clarification #30792wording 2021-06-01 FE FE Radiator Screens #30575other 2021-06-01 SRF SRF3 Alternator Pulley #30684weight 2021-04-01 SM Updates - Obsolete Parts & BOP Parts #30438other 2021-03-01 SRF Mandatory identification: #30223engine 2020-12-01 FE FE / FE2 Spring Updates #29689suspension & brakes 2020-12-01 SRF SRF Shocks, Springs and Ride Height. #29688suspension & brakes
	Road America Runoffs 20202020-10-02														2:42.209Kyle Greenhill · fastest of 77 · top 5 within 0.5s	2:43.748Preston Pardus · fastest of 75 · top 5 within 1.0s	121.3Kyle Greenhill
12 rule changes (SRF: 5, FE: 5, SM: 2)4 suspension & brakes · 3 weight · 2 aero · 1 engine · 1 tyres & wheels · 1 othershowhide 2020-10-01 FE FE Gurney Flap Spec Update #29445aero 2020-10-01 SM Radiator E&O Clarifications #29294engine 2020-08-01 SM Modifications to prevent failures of Rear Brake Caliper Pin #28953suspension & brakes 2020-06-01 FE FE Gurney flap wicker clarification #28885aero 2020-05-01 FE FE spring rule update changed to November 1, 2020 #28814suspension & brakes 2020-05-01 SRF SRF Bump Stop Correction #27019suspension & brakes 2020-01-01 FE Request for FE / FE2 preparation rules update #27722weight 202-01-01 SRF SRF Rain / Brake Rule - BoD approved as follows #34958suspension & brakes 2019-12-01 FE 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				1:55.124Bryce Cornet · fastest of 8 · top 5 within 2.3s	2:15.816Bryce Cornet · fastest of 8 · top 5 within 4.9s	135.7Bryce Cornet			1:54.710Mark Snyder · fastest of 9 · top 5 within 1.3s	1:55.648Mark Snyder · fastest of 9 · top 5 within 0.9s	135.5James Libecco			2:14.552Todd Buras · fastest of 60 · top 5 within 0.2s	2:16.459Elivan Goulart · fastest of 56 · top 5 within 0.4s	119.8Jim Drago
10 rule changes (SRF: 1, FE: 5, SM: 4)4 tyres & wheels · 1 engine · 1 suspension & brakes · 1 weight · 1 wording · 2 othershowhide 2019-10-01 FE FE Wet Tire E&O #27365tyres & wheels 2019-07-01 FE FE Tire Update #27029tyres & wheels 2019-07-01 SRF SRF Dash Windscreen Kit #27028other 2019-05-31 FE FE Anti-Roll Bar Clarification #26912suspension & brakes 2019-05-31 FE FE / FE2 Updated Bubble Tail Rule #26913other 2019-03-01 FE Request to Update Hoosier Rain Tire Part Number for the FE cars #26235tyres & wheels 2019-03-01 SM Request to allow aftermarket fuel filters. #26370wording 2019-02-01 SM Request 99-00 replacement Wire harnesses #25602engine 2019-02-01 SM Organize and Clarify 9.1.7.C.1.o. #25913weight 2019-02-01 SM Strike Tire Tread Language #26123tyres & wheels
	Sonoma Raceway Runoffs 20182018-10-10				1:37.598Bryce Cornet · fastest of 13 · top 5 within 0.9s	1:37.909Bryce Cornet · fastest of 12 · top 5 within 1.3s	124.1Melvin David Kemper Jr			1:37.517Mark Snyder · fastest of 10 · top 5 within 1.4s	1:38.504Lee Rackley · fastest of 10 · top 5 within 0.8s	124.7Quinten Nelson			1:54.355Ken Sutherland · fastest of 48 · top 5 within 0.7s	1:55.278Michael Carter · fastest of 48 · top 5 within 0.3s	102.2Danny Steyn
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		1:41.231Jarret Voorhies · fastest of 16 · top 5 within 1.7s	1:41.146Jarret Voorhies · fastest of 16 · top 5 within 1.2s		-12.623squal -10.342s	88.9%qual 90.7%	1:39.177Elliot Finlayson · fastest of 35 · top 5 within 1.3s	1:39.726Elliot Finlayson · fastest of 35 · top 5 within 0.8s		-14.043squal -12.396s	87.7%qual 88.9%	1:58.306Chris Haldeman · fastest of 86 · top 5 within 0.5s	1:59.100Michael Gagliardo · fastest of 83 · top 5 within 0.6s		+5.331squal +6.733s	104.7%qual 106.0%
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		1:26.043Jacob Loomis · fastest of 8 · top 5 within 3.1s	1:27.922Jacob Loomis · fastest of 8 · top 5 within 2.7s		-9.699squal -11.301s	90.1%qual 88.4%	1:27.636Scott Rettich · fastest of 9 · top 5 within 1.7s	1:30.563Hanna Zellers · fastest of 9 · top 5 within 2.2s		-7.058squal -9.708s	92.8%qual 90.0%	1:40.514Justin Hille · fastest of 45 · top 5 within 0.3s	1:40.764Michael Carter · fastest of 44 · top 5 within 0.3s		+3.143squal +3.170s	103.2%qual 103.3%
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		1:57.804Joseph Burton-Harris · fastest of 10 · top 5 within 2.3s	1:58.029Joseph Burton-Harris · fastest of 10 · top 5 within 1.7s		-18.671squal -16.502s	86.3%qual 87.7%	1:57.824Scott Rettich · fastest of 16 · top 5 within 1.0s	1:59.040Scott Rettich · fastest of 16 · top 5 within 1.3s		-17.660squal -16.482s	87.1%qual 87.7%	2:18.661Andrew Carbonell · fastest of 62 · top 5 within 0.6s	2:24.067Todd Lamb · fastest of 59 · top 5 within 0.8s		+7.367squal +4.355s	105.4%qual 103.2%

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.