BoP Lab / Classes / FE

FE vs F6 vs SRF vs GT1 pace at every track

Lap times across years say as much about the weather as the class. % of FE is each class's best lap as a share of FE'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-SpecEPvsF6 ×FAFCFE×FE2FFFPFVFXvsGT1 ×GT2GTXHPPP2SMSMXvsSRF ×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: FE 100.0% of FE Scott Rettich, Daytona International Speedway Runoffs 2015 race · SRF 107.8% of FE Todd Harris, Mid-Ohio Sports Car Course Runoffs 2016 race · GT1 88.5% of FE Michael Lewis, Daytona International Speedway Runoffs 2015 qualifying

% of FELap times

FEF6SRFGT1solid race · dashed qualifying · slower is lower

FEF6SRFGT1solid race · dashed qualifying · each class's best lap as a share of FE's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker

	Event	FE			F6					SRF					GT1
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs FE	% of FE	Qual best	Race best	Trap	vs FE	% of FE	Qual best	Race best	Trap	vs FE	% of FE
	Road America Runoffs 20262026-09-28				2:18.489Calvin Stewart · fastest of 13 · top 5 within 4.2s-0.617s (-0.44%)	2:20.255James Weida · fastest of 13 · top 5 within 2.0s+1.415s (+1.02%)	143.0Calvin Stewart-4.5 mph (-3.1%)								2:02.981Tony Ave · fastest of 12 · top 5 within 4.6s+1.708s (+1.41%)	2:04.611Tony Ave · fastest of 12 · top 5 within 3.9s+0.553s (+0.45%)	177.9Tony Ave-2.7 mph (-1.5%)
14 rule changes (FE: 2, SRF: 3, GT1: 9)4 weight · 2 cars added · 1 engine · 1 removed · 1 suspension & brakes · 5 othershowhide 2026-09-01 SRF GCR Rain/Brake Light Correction #40579suspension & brakes 2026-08-01 GT1 Request TA Cup Cars Into GT1 #40250other 2026-07-01 GT1 Request TA Cup Cars Into GT1 #40250cars added 2026-07-01 GT1 Lamborghini Huracan Super Trofeo in GT1 #40288cars added 2026-06-01 GT1 Request for Huracan GT3 Evo Weight Reduction to 2950lbs #40147weight -50 lbs 2026-03-01 GT1 Reduce Weight for GM 275ci Carbureted V6s #39713weight 2026-03-01 GT1 Remove GT3U from GCR as it is now in STU #39862removed 2026-03-01 SRF SRF3 Spark Plugs #39899other 2026-02-01 GT1 Request for Addition of Porsche 992.1 GT3 Cup into GT1 #39322other 2026-01-01 FE FE & FE2 Rule Updates #39484engine 2026-01-01 GT1 NSX Parity With Other GT3s Let Alone a GT1 Car #39311weight -100 lbs 2025-10-01 FE FE & FE2 Bubble Tail #38978other 2025-10-01 GT1 RM 25-06 GT1 reclassify the Acura NSX GT3 EVO 22 to GT1-ST #39101weight 2025-10-01 SRF Add HD Oil Cooler #38979other
	Road America Runoffs 20252025-09-29														2:01.273Tony Ave · fastest of 14 · top 5 within 7.7s-1.262s (-1.03%)	2:04.058Tony Ave · fastest of 12 · top 5 within 5.8s-2.835s (-2.23%)	180.6Dave Ruehlow-0.4 mph (-0.2%)
11 rule changes (FE: 2, SRF: 2, GT1: 7)2 cars added · 2 engine · 2 weight · 1 aero · 1 induction · 1 suspension & brakes · 2 othershowhide 2025-09-01 FE FE & FE2 Rule Updates #38901weight 2025-09-01 GT1 Correction to Limited prep LS Chevy engine for GT1 #38902engine 2025-04-01 SRF Driver Safety & Comfort #37966other 2025-04-01 SRF Update SADEV transmission specs #37992other 2025-03-01 GT1 Request to Classify Acura NSX GT3 Evo 22 #37367cars added 2025-01-01 GT1 Addition of a limited prep LS Chevy engine for GT1 #37045engine 2025-01-01 GT1 Correct language regarding OEM Areo Devices #37137aero 2025-01-01 GT1 GT1-ST Adjustments #37481weight 2024-12-01 FE Brake Line to A-Arm Covers #37110suspension & brakes 2024-12-01 GT1 Lamborghini Huracan GT3 Evo Restrictor Help #36254induction 2024-11-01 GT1 Request to Classify Mazda 26B Engine #36230cars added
	Road America Runoffs 20242024-10-01				2:19.106Calvin Stewart · fastest of 22 · top 5 within 1.3s	2:18.840James Weida · fastest of 22 · top 5 within 1.0s	147.6Calvin Stewart								2:02.535Dave Ruehlow · fastest of 10 · top 5 within 4.6s-0.401s (-0.33%)	2:06.893Dave Ruehlow · fastest of 6 · top 5 within 50.8s+1.611s (+1.29%)	181.0Dave Ruehlow+0.5 mph (+0.3%)
23 rule changes (FE: 5, SRF: 10, GT1: 8)5 tyres & wheels · 3 engine · 3 suspension & brakes · 3 weight · 1 aero · 1 cars added · 2 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 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 2024-05-01 GT1 Request for Spec Line 1010 Reconsideration #35009weight +300 lbs 2024-05-01 GT1 Camaro 1993- and 2010- #35652other 2024-02-01 GT1 Rear Blade Spoiler Clarification #35261aero 2024-02-01 GT1 GT Direct Injection allowance and rules #35437engine 2024-02-01 GT1 GT2/3 remove Direction Injection not allowed in Spec line notes #35439engine 2024-01-01 FE Update FE Rain Light Rule #34707other 2024-01-01 FE FE/FE2 rule update #35269other 2024-01-01 GT1 Request for Acceptance of Lamborghini Huracan GT3 in GT1-ST #34929cars added 2024-01-01 GT1 Cylinder heads #35040engine 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 2023-12-01 GT1 Errors in GTCS Headings and Use of the Terms Category and ClassChange existing GTL and GTA Rules #34453weight 2023-10-01 SRF SRF Radiator Rule Update #34805other
	Virginia International Raceway Runoffs 20232023-09-23				1:57.437Calvin Stewart · fastest of 9 · top 5 within 4.7s	1:58.816Calvin Stewart · fastest of 9 · top 5 within 3.6s	144.0Calvin Stewart								1:48.203David Pintaric · fastest of 5 · top 5 within 22.4s+1.395s (+1.31%)		178.1David Pintaric-3.6 mph (-2.0%)
13 rule changes (FE: 3, SRF: 3, GT1: 7)3 weight · 2 cars added · 2 suspension & brakes · 2 tyres & wheels · 1 aero · 1 induction · 2 othershowhide 2023-06-01 SRF Hoosier SRF Wet Front Tire Rule Update #34189tyres & wheels 2023-05-01 GT1 Please classify Fields Cardinal V8 #33784cars added 2023-05-01 SRF Update SRF Front W2 Rain Tire Part Number #34118tyres & wheels 2023-04-01 FE Update FE SADEV Transmission Rule #33883other 2023-04-01 GT1 Mercedes AMG GT3 Notes #33804other 2023-03-01 SRF Update SRF Brake Rule #33469suspension & brakes 2023-02-01 GT1 Sequential Transmission Weight Penalty #33503weight 2023-02-01 GT1 GT1 Porsche 992 #33730cars added 2022-12-01 GT1 GT2 (TA2)/GTA Part Number Update #33315induction 2022-12-01 GT1 Request to Reduce Trans Am Bodywork Weight Penalty #33331weight 2022-12-01 GT1 Request for Reduction in FR9 Weight Penalty #33332weight 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														1:46.808David Pintaric · fastest of 8 · top 5 within 3.7s+2.951s (+2.84%)	2:18.094David Pintaric · fastest of 7 · top 5 within 13.7s+29.532s (+27.20%)	181.7Adam Romito-1.5 mph (-0.8%)
13 rule changes (FE: 4, SRF: 3, GT1: 6)4 tyres & wheels · 2 cars added · 2 engine · 2 suspension & brakes · 2 weight · 1 othershowhide 2022-09-01 FE Engine Heat Shield & Insulation #33019engine 2022-09-01 GT1 Tail lights on all GT category race cars. #32799suspension & brakes 2022-08-01 GT1 GT-1/TransAm rules simplification/modernizing #32763weight 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 2022-03-01 GT1 Mercedes Benz AMG GT3 in GT1 #31883cars added 2022-03-01 GT1 Wheel Widths #32205tyres & wheels 2022-02-01 GT1 Wheel Widths #31844tyres & wheels 2021-12-01 FE Two FE2 Rule Updates #31524other 2021-12-01 SRF Three Updates to SRF Rules #31523weight 2021-10-01 GT1 Request car classification #31032cars added
	Indianapolis Motor Speedway Runoffs 20212021-09-25														1:35.279Michael Lewis · fastest of 20 · top 5 within 0.6s-0.729s (-0.76%)	1:53.220David Pintaric · fastest of 14 · top 5 within 3.8s+17.033s (+17.71%)	180.2Tom Smith
11 rule changes (FE: 4, SRF: 6, GT1: 1)2 engine · 2 suspension & brakes · 2 tyres & wheels · 1 weight · 2 wording · 2 othershowhide 2021-08-01 GT1 Request to Update GTA Obsolete Part Numbers #30615wording 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 2021-03-01 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														2:02.936Ernie Francis Jr · fastest of 16 · top 5 within 3.4s	2:05.282Ernie Francis Jr · fastest of 16 · top 5 within 3.4s	180.5Simon Gregg
22 rule changes (FE: 5, SRF: 5, GT1: 12)6 aero · 5 weight · 3 suspension & brakes · 2 cars added · 1 engine · 1 induction · 1 tyres & wheels · 3 othershowhide 2020-10-01 FE FE Gurney Flap Spec Update #29445aero 2020-09-01 GT1 GT Category Wording #29193induction 2020-08-01 GT1 Request to Allow New Trans Am Legal Engines in GT1 #29002engine 2020-07-01 GT1 TA2 Gurney flap wicker clarification #28874aero 2020-07-01 GT1 STO Gurney flap wicker clarification #28883aero 2020-07-01 GT1 GT1 Gurney flap wicker clarification #28886aero 2020-07-01 GT1 GT Gurney flap wicker clarification #28909aero 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 2020-02-01 GT1 Windshield Clips #27323other 2020-01-01 FE Request for FE / FE2 preparation rules update #27722weight 2020-01-01 GT1 Request to classify the Ford Coyote 3rd Gen OEM #27146cars added 2020-01-01 GT1 Request Factory Five Daytona coupe classification #26308cars added 2020-01-01 GT1 Request to Adjust Transmission Penalty #27750weight 2020-01-01 GT1 Request to Reduce Additional Weight for 18 #27751weight 2020-01-01 GT1 Request for Five Star Nascar Compliant Bodywork #27756other 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	1:54.710Mark Snyder · fastest of 9 · top 5 within 1.3s	1:55.648Mark Snyder · fastest of 9 · top 5 within 0.9s	135.5James Libecco											1:43.857Tony Ave · fastest of 12 · top 5 within 3.9s	1:48.562Tony Ave · fastest of 11 · top 5 within 11.4s	183.2Tony Ave	-7.086squal -10.853s	93.9%qual 90.5%
12 rule changes (FE: 5, SRF: 1, GT1: 6)3 cars added · 3 tyres & wheels · 2 suspension & brakes · 1 aero · 1 engine · 2 othershowhide 2019-10-01 FE FE Wet Tire E&O #27365tyres & wheels 2019-08-31 GT1 Request to classify Porsche 944/968 #26242cars added 2019-07-01 FE FE Tire Update #27029tyres & wheels 2019-07-01 GT1 Clarify Trans Am Legal Bodywork and Wing #26953aero 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 2019-05-01 GT1 Request GTX Fuel injection for previous GT-1 tube frame cars #26141engine 2019-05-01 GT1 Request to Classify Ligier JS2 R #26535cars added 2019-04-01 GT1 Request Ride Height Clarification #26600suspension & brakes 2019-03-01 FE Request to Update Hoosier Rain Tire Part Number for the FE cars #26235tyres & wheels 2019-01-01 GT1 GTX Homologation table update #26034cars added
	Sonoma Raceway Runoffs 20182018-10-10	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											1:35.673Michael Lewis · fastest of 8 · top 5 within 7.1s	1:37.516Michael Lewis · fastest of 7 · top 5 within 5.3s	111.6Preston Calvert	-0.988squal -1.844s	99.0%qual 98.1%
No rule changes on record between these events
	Indianapolis Motor Speedway Runoffs 20172017-09-25	1:39.177Elliot Finlayson · fastest of 35 · top 5 within 1.3s	1:39.726Elliot Finlayson · fastest of 35 · top 5 within 0.8s							1:51.573Thomas Kirchman · fastest of 50 · top 5 within 2.8s	1:53.769Todd Harris · fastest of 45 · top 5 within 0.2s		+14.043squal +12.396s	114.1%qual 112.5%	1:36.008David Pintaric · fastest of 17 · top 5 within 2.2s	1:36.187Cliff Ebben · fastest of 16 · top 5 within 1.5s		-3.539squal -3.169s	96.5%qual 96.8%
No rule changes on record between these events
	Mid-Ohio Sports Car Course Runoffs 20162016-09-19	1:27.636Scott Rettich · fastest of 9 · top 5 within 1.7s	1:30.563Hanna Zellers · fastest of 9 · top 5 within 2.2s							1:37.344Mike Miserendino · fastest of 27 · top 5 within 0.8s	1:37.621Todd Harris · fastest of 27 · top 5 within 0.6s		+7.058squal +9.708s	107.8%qual 111.1%	1:21.927Cliff Ebben · fastest of 8 · top 5 within 2.5s	1:22.866Michael Lewis · fastest of 7 · top 5 within 2.1s		-7.697squal -5.709s	91.5%qual 93.5%
No rule changes on record between these events
	Daytona International Speedway Runoffs 20152015-09-21	1:57.824Scott Rettich · fastest of 16 · top 5 within 1.0s	1:59.040Scott Rettich · fastest of 16 · top 5 within 1.3s							2:14.306Cliff White · fastest of 39 · top 5 within 1.2s	2:16.700Cliff White · fastest of 38 · top 5 within 0.5s		+17.660squal +16.482s	114.8%qual 114.0%	1:44.244Michael Lewis · fastest of 11 · top 5 within 7.8s	1:47.116Michael Lewis · fastest of 7 · top 5 within 8.3s		-11.924squal -13.580s	90.0%qual 88.5%

By track

Track	Events	Typical % of FE	Best	Latest
Road America	4	0 of 4 with FE
Virginia International Raceway	3	100.0%1 of 3 with FE	100.0%Runoffs 2019	100.0%Runoffs 2019
Indianapolis Motor Speedway	2	100.0%1 of 2 with FE	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	100.0%	100.0%Runoffs 2018	100.0%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 FE'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.