BoP Lab / Classes / F6

F6 vs F5 vs FB vs FC pace at every track

Lap times across years say as much about the weather as the class. % of F6 is each class's best lap as a share of F6'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-SpecEPvsF5 ×F6×FAvsFB ×vsFC ×FE2FFFPFVFXGT1GT2GTXHPPP2SMSMXSRF3STLSTUT1T2T3T4Show 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: F6 100.0% of F6 Calvin Stewart, Virginia International Raceway Runoffs 2023 race · FC 93.6% of F6 Nolan Allaer, Virginia International Raceway Runoffs 2023 race

% of F6Lap times

F6F5FBFCsolid race · dashed qualifying · slower is lower

F6F5FBFCsolid race · dashed qualifying · each class's best lap as a share of F6's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker

	Event	F6			F5					FB					FC
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs F6	% of F6	Qual best	Race best	Trap	vs F6	% of F6	Qual best	Race best	Trap	vs F6	% of F6
	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%)											2:10.686Brandon Dixon · fastest of 10 · top 5 within 4.0s-0.573s (-0.44%)	2:11.389Brandon Dixon · fastest of 10 · top 5 within 2.7s-1.435s (-1.08%)	143.3Dean Kiriluk-1.8 mph (-1.2%)	-8.866squal -7.803s	93.7%qual 94.4%
2 rule changes (FC: 2)1 weight · 1 othershowhide 2026-01-01 FC F2000 MZR Spec Line Clarity/Revision Requested #38927other 2026-01-01 FC Adjust F2000 Metrik ZF2 weight #39612weight -20 lbs
	Road America Runoffs 20252025-09-29														2:11.259Brandon Dixon · fastest of 10 · top 5 within 2.7s-0.367s (-0.28%)	2:12.824Brandon Dixon · fastest of 9 · top 5 within 2.3s+1.290s (+0.98%)	145.1Brandon Dixon+0.9 mph (+0.6%)
2 rule changes (FC: 2)1 tyres & wheels · 1 weightshowhide 2024-11-01 FC 9.1.1.10.h. FC Tire Rule #36533tyres & wheels 2024-11-01 FC Change FF/FC Weight with Sequential Gearbox #36651weight
	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											2:11.626Timothy Minor · fastest of 10 · top 5 within 1.3s-1.018s (-0.77%)	2:11.534Michael Varacins · fastest of 9 · top 5 within 1.8s-2.074s (-1.55%)	144.2Michael Varacins+1.8 mph (+1.2%)	-7.306squal -7.480s	94.7%qual 94.6%
2 rule changes (FC: 2)2 weightshowhide 2024-04-01 FC Four Pot Calipers #35481weight 2024-01-01 FC Please correct omitted punctuation #34890weight
	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											1:50.281Nolan Allaer · fastest of 11 · top 5 within 2.3s+0.386s (+0.35%)	1:51.169Nolan Allaer · fastest of 11 · top 5 within 2.5s-16.690s (-13.05%)	143.5Robert Allaer+2.3 mph (+1.7%)	-7.647squal -7.156s	93.6%qual 93.9%
3 rule changes (FC: 3)1 engine · 1 tyres & wheels · 1 weightshowhide 2023-07-01 FC Review FC Runoffs Tire Marking Rule #34274tyres & wheels 2023-06-01 FC USF2000 Van Diemen with Mazda MZR LF-DE 2.0L in FC #34329weight 2023-01-01 FC E&O 9.1.1.B.16.j #33634engine
	Virginia International Raceway Runoffs 20222022-09-24				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%)								1:49.895Nolan Allaer · fastest of 12 · top 5 within 1.5s-1.305s (-1.17%)	2:07.859Nolan Allaer · fastest of 13 · top 5 within 3.8s+15.685s (+13.98%)	141.2Tim Minor-0.6 mph (-0.4%)
11 rule changes (F5: 6, FC: 5)5 engine · 2 induction · 1 tyres & wheels · 1 wording · 2 othershowhide 2022-09-01 F5 Intake Boots Correction #33028induction 2022-08-01 F5 Ensure availability of ECU for Rotax engines #32695engine 2022-07-01 F5 Clarify stepped exhaust header references #32743engine 2022-07-01 FC Add Specification to Performance Electronics ECU for Ford Zetec #32761engine 2022-06-01 F5 593 carb boot availability and oil pump clarification #32527induction 2022-03-01 F5 E&O class name #32194other 2022-01-01 F5 Data Box Mounting Plate #31638other 2022-01-01 FC Clean up Chassis/Frame section #31867engine 2021-12-01 FC Clarify Zetec ECU requirements #31554engine 2021-11-01 FC Clarify composite anti-intrusion panel language #31426wording 2021-11-01 FC Clarify tire marking requirements #31455tyres & wheels
	Indianapolis Motor Speedway Runoffs 20212021-09-25				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								1:36.787Trent Walko · fastest of 31 · top 5 within 1.7s+0.451s (+0.47%)	1:36.980Simon Sikes · fastest of 31 · top 5 within 2.0s+0.090s (+0.09%)	141.6Tim Minor
4 rule changes (F5: 3, FC: 1)1 engine · 1 tyres & wheels · 1 weight · 1 wordingshowhide 2021-08-01 F5 Clarify allowable assisted shifting systems #30871wording 2021-08-01 F5 Request to correct terminology #30976tyres & wheels 2021-06-01 F5 Request to Allow Rotax 593 HO Engine #30712engine 2021-03-01 FC Request for FC Weight Change #30171weight
	Road America Runoffs 20202020-10-02				2:20.954Calvin Stewart · fastest of 16 · top 5 within 1.8s	2:21.391James Weida · fastest of 14 · top 5 within 1.5s	143.2Aaron Ellis								2:12.644Robert Allaer · fastest of 13 · top 5 within 2.1s	2:13.608Robert Allaer · fastest of 11 · top 5 within 1.2s	142.4Robert Allaer
10 rule changes (F5: 6, FC: 4)4 engine · 2 induction · 1 weight · 3 othershowhide 2020-10-01 F5 Request to Update Suzuki Engine Years for F500 #29453engine 2020-10-01 FC Urgent: SCCA PE3 map unsuitable #29475induction 2020-08-01 FC Request for weight adjustments to equalize FC competition. #28888weight 2020-07-01 F5 Request for Cockpit Adjustment of External Jetting Devices #28359other 2020-07-01 F5 Two Stroke Motors (reply to #28359 WDYT) #28816engine 2020-07-01 F5 Re letter requesting driver adjustable carb mixture #28840other 2020-07-01 F5 #28359 WDYT Request for Cockpit Adjustment #28875other 2020-01-01 F5 Change 600cc restrictor size #27883induction 2019-12-01 FC Request for Better Zetec Connecting Rods #27710engine 2019-12-01 FC Add Alternate Piston #27795engine
	Virginia International Raceway Runoffs 20192019-10-05				1:57.361Wiley Mcmahan · fastest of 15 · top 5 within 3.8s	1:57.572Wiley Mcmahan · fastest of 15 · top 5 within 4.0s	142.8Eric McRee			1:54.469Pete Frost · only car	1:57.688Pete Frost · only car	145.9Pete Frost			1:51.200Robert Allaer · fastest of 10 · top 5 within 3.1s	1:52.174Robert Allaer · fastest of 9 · top 5 within 2.7s	141.8Robert Allaer
3 rule changes (F5: 1, FC: 2)3 weightshowhide 2019-08-31 F5 Request for Weight Increase for Motorcycle Powered Cars #27214weight +25 lbs 2019-05-01 FC E&O Wiseco piston and Crower connecting rod #26659weight 2019-01-01 FC Correct Wiseco piston and connecting rod #25809weight
	Sonoma Raceway Runoffs 20182018-10-10				1:41.807Jeff Jorgenson · fastest of 5 · top 5 within 6.6s	1:42.491David Lapham · fastest of 5 · top 5 within 9.5s	113.3David Lapham			1:28.612J R Osborne · fastest of 7 · top 5 within 3.3s	1:31.189J R Osborne · fastest of 7 · top 5 within 3.7s	140.5J R Osborne			1:32.571Timothy de Silva · fastest of 16 · top 5 within 1.8s	1:34.053Mitch Egner · fastest of 12 · top 5 within 1.6s	133.1Robert Armington
No rule changes on record between these events
	Indianapolis Motor Speedway Runoffs 20172017-09-25				1:43.136Wiley Clinton McMahan · fastest of 38 · top 5 within 1.4s	1:42.860Wiley Clinton McMahan · fastest of 37 · top 5 within 1.6s				1:33.746Gary Hickman · fastest of 18 · top 5 within 3.3s	1:33.702Alex Mayer · fastest of 17 · top 5 within 3.0s				1:36.336Austin McCusker · fastest of 14 · top 5 within 2.3s	1:36.890Tim Minor · fastest of 14 · top 5 within 3.8s
No rule changes on record between these events
	Mid-Ohio Sports Car Course Runoffs 20162016-09-19				1:28.528Calvin Stewart · fastest of 14 · top 5 within 3.9s	1:29.853Steven Thompson · fastest of 12 · top 5 within 4.5s				1:19.886Alex Mayer · fastest of 10 · top 5 within 1.5s	1:21.015Jeremy Hill · fastest of 10 · top 5 within 1.2s				1:21.962John LaRue · fastest of 7 · top 5 within 2.6s	1:22.049Nigel Saurino · fastest of 7 · top 5 within 3.0s
No rule changes on record between these events
	Daytona International Speedway Runoffs 20152015-09-21				2:01.824W. Clint McMahan · fastest of 16 · top 5 within 3.0s	2:03.298Matthew Strand · fastest of 15 · top 5 within 4.9s				1:50.711J R Osborne · fastest of 20 · top 5 within 1.1s	1:51.616J R Osborne · fastest of 19 · top 5 within 2.1s				1:54.477Yufeng Luo · fastest of 11 · top 5 within 2.5s	1:55.135Yufeng Luo · fastest of 10 · top 5 within 2.1s

By track

Track	Events	Typical % of F6	Best	Latest
Road America	4	100.0%2 of 4 with F6	100.0%Runoffs 2024	100.0%Runoffs 2026
Virginia International Raceway	3	100.0%1 of 3 with F6	100.0%Runoffs 2023	100.0%Runoffs 2023
Indianapolis Motor Speedway	2	0 of 2 with F6
Daytona International Speedway	1	0 of 1 with F6
Mid-Ohio Sports Car Course	1	0 of 1 with F6
Sonoma Raceway	1	0 of 1 with F6

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 F6'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.