BoP Lab / Classes / FB

FB vs SRF vs F5 vs P2 pace at every track

Lap times across years say as much about the weather as the class. % of FB is each class's best lap as a share of FB'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 ×FAFB×FCFE2FFFPFVFXGT1GT2GTXHPPvsP2 ×SMSMXvsSRF ×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: FB 100.0% of FB J R Osborne, Daytona International Speedway Runoffs 2015 race · SRF 119.0% of FB Thomas Kirchman, Indianapolis Motor Speedway Runoffs 2017 qualifying · F5 99.9% of FB Wiley Mcmahan, Virginia International Raceway Runoffs 2019 race · P2 93.7% of FB Greg Gyann, Virginia International Raceway Runoffs 2019 race

% of FBLap times

FBSRFF5P2solid race · dashed qualifying · slower is lower

FBSRFF5P2solid race · dashed qualifying · each class's best lap as a share of FB's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker

	Event	FB			SRF					F5					P2
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs FB	% of FB	Qual best	Race best	Trap	vs FB	% of FB	Qual best	Race best	Trap	vs FB	% of FB
	Road America Runoffs 20262026-09-28														2:10.606Greg Gyann · fastest of 11 · top 5 within 5.3s+3.201s (+2.51%)	2:09.441Mike Reupert · fastest of 11 · top 5 within 4.2s+1.119s (+0.87%)	155.0Matt Strand+2.4 mph (+1.6%)
6 rule changes (SRF: 5, P2: 1)1 suspension & brakes · 1 weight · 4 othershowhide 2026-09-01 SRF GCR Rain/Brake Light Correction #40579suspension & brakes 2026-03-01 SRF SRF3 Spark Plugs #39899other 2025-10-01 SRF Add HD Oil Cooler #38979other 2025-04-01 SRF Driver Safety & Comfort #37966other 2025-04-01 SRF Update SADEV transmission specs #37992other 2024-12-01 P2 2000 cc Pinto Engine Car Weight #37187weight
	Road America Runoffs 20242024-10-01														2:07.405Bart Wolf · fastest of 14 · top 5 within 3.0s-1.109s (-0.86%)	2:08.322Bart Wolf · fastest of 13 · top 5 within 0.6s-1.471s (-1.13%)	152.5Lucian Pancea-0.6 mph (-0.4%)
15 rule changes (SRF: 10, P2: 5)4 engine · 4 tyres & wheels · 3 suspension & brakes · 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 2024-05-01 P2 CN Spec ECU #35835engine 2024-05-01 P2 E&O - Correct FIA Group CN spec line notes #35900tyres & wheels 2024-01-01 P2 E&O - Clarify B.1 modified engine range in AMAC spec lines #35225engine 2024-01-01 P2 Replacement Engine Crankcase for 07/08 Suzuki GSX-R1000 Engines #35340engine 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 P2 Correct Table 1 for Engine Date Range Specifications #35182engine 2023-10-01 SRF SRF Radiator Rule Update #34805other
	Virginia International Raceway Runoffs 20232023-09-23														1:48.590Greg Gyann · fastest of 12 · top 5 within 1.7s+1.024s (+0.95%)	1:48.829Lucian Pancea · fastest of 11 · top 5 within 0.9s-27.005s (-19.88%)	150.9Lucian Pancea-0.2 mph (-0.2%)
11 rule changes (SRF: 3, P2: 8)3 tyres & wheels · 3 weight · 2 engine · 1 cars added · 1 suspension & brakes · 1 wordingshowhide 2023-06-01 SRF Hoosier SRF Wet Front Tire Rule Update #34189tyres & wheels 2023-05-01 P2 Clarify minimum side body height requirement #34143tyres & wheels 2023-05-01 P2 Clarify closed cockpit single seat car allowance #34144wording 2023-05-01 SRF Update SRF Front W2 Rain Tire Part Number #34118tyres & wheels 2023-04-01 P2 Remove redundant effective date language and update engine table #34012engine 2023-04-01 P2 E&O - Correct dimensional equivalents #34038weight 2023-03-01 SRF Update SRF Brake Rule #33469suspension & brakes 2023-01-01 P2 Request to Classify Sebeco NP01 #33378cars added 2023-01-01 P2 Radical spec line clarifications #33485weight 2023-01-01 P2 E&O original class intent #33519weight 2023-01-01 P2 Update Engine Table Spec Line B.1 #33608engine
	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%)			1:47.566Tim Day Jr · fastest of 12 · top 5 within 3.0s-1.545s (-1.42%)	2:15.834Greg Gyann · fastest of 12 · top 5 within 10.1s+25.576s (+23.20%)	151.1Robert Iversen+1.8 mph (+1.2%)
19 rule changes (SRF: 3, F5: 6, P2: 10)4 engine · 4 tyres & wheels · 2 induction · 2 weight · 1 aero · 1 suspension & brakes · 1 wording · 4 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 2022-06-01 F5 593 carb boot availability and oil pump clarification #32527induction 2022-06-01 SRF SRF Tire Rule Update #32614tyres & wheels 2022-06-01 SRF Brake, seal, and air filter clarifications #32670suspension & brakes 2022-05-01 P2 E&O Clarification of Chassis Construction Requirements #32469tyres & wheels 2022-05-01 P2 Clean up P2 wording #32525wording 2022-04-01 P2 After Market to Aftermarket #32373other 2022-03-01 F5 E&O class name #32194other 2022-03-01 P2 Add spec line for Beasley B2 #32147weight 2022-03-01 P2 E&O Table 1 spec line wing terminology #32148aero 2022-03-01 P2 E&O class name #32196other 2022-02-01 P2 E&O Engine section #31969engine 2022-01-01 F5 Data Box Mounting Plate #31638other 2022-01-01 P2 E&O letter #31539 – Control Area definition #31783tyres & wheels 2021-12-01 P2 BoP adjustment effective 1-1-22 #31538engine 2021-12-01 P2 E&O clarification of "Control Area" definition #31539tyres & wheels 2021-12-01 SRF Three Updates to SRF Rules #31523weight
	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			1:33.235Tim Day Jr · fastest of 16 · top 5 within 3.3s+1.409s (+1.53%)	1:35.322Tim Day Jr · fastest of 10 · top 5 within 4.8s+2.841s (+3.07%)	150.3Robert Iversen
17 rule changes (SRF: 6, F5: 3, P2: 8)6 engine · 3 tyres & wheels · 1 induction · 1 suspension & brakes · 1 weight · 1 wording · 4 othershowhide 2021-09-01 P2 P2 CN Engine Rebuild Clarification #31000engine 2021-08-01 F5 Clarify allowable assisted shifting systems #30871wording 2021-08-01 F5 Request to correct terminology #30976tyres & wheels 2021-08-01 P2 F5 P2 Conversion #30856other 2021-08-01 P2 Clarify minimum body width requirement #30859tyres & wheels 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 F5 Request to Allow Rotax 593 HO Engine #30712engine 2021-06-01 SRF SRF3 Alternator Pulley #30684weight 2021-05-01 P2 E&O tonneau cover provision in cockpit opening section #30459other 2021-05-01 P2 Remove effective dates in Table 1 #30468other 2021-05-01 P2 E&O Maximum Valves Per Cylinder #30560engine 2021-03-01 P2 Add a new spec line for a 2-cycle, 3-cylinder engine up to 820cc #30272engine 2021-03-01 SRF Mandatory identification: #30223engine 2020-12-01 P2 Balance of Performance adjustments effective 01-01-2021 #29822induction 2020-12-01 SRF SRF Shocks, Springs and Ride Height. #29688suspension & brakes
	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			2:08.514Robert Iversen · fastest of 12 · top 5 within 3.0s	2:09.793Robert Iversen · fastest of 12 · top 5 within 3.9s	153.1Robert Iversen
17 rule changes (SRF: 5, F5: 6, P2: 6)4 engine · 3 induction · 2 suspension & brakes · 1 aero · 1 cars added · 1 tyres & wheels · 1 weight · 4 othershowhide 2020-10-01 F5 Request to Update Suzuki Engine Years for F500 #29453engine 2020-09-01 P2 E&O clarification of P2 rear wing requirements #29205aero 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 2020-06-01 P2 Classify Elan NP01 in P2 Table 1 #28812cars added 2020-05-01 P2 SCCA Enterprises ESR / P2 engine restrictor testing #28669induction 2020-05-01 SRF SRF Bump Stop Correction #27019suspension & brakes 2020-04-01 P2 Add ESR inlet restrictor #27869induction 2020-03-01 P2 Request for Fly by Wire Rule Wording Change #28247engine 2020-01-01 F5 Change 600cc restrictor size #27883induction 2020-01-01 P2 Request for addition of BMW Engine in P2 Engine Table #27821engine 202-01-01 SRF SRF Rain / Brake Rule - BoD approved as follows #34958suspension & brakes 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	1:54.469Pete Frost · only car	1:57.688Pete Frost · only car	145.9Pete Frost						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	-0.116squal +2.892s	99.9%qual 102.5%	1:49.111Robert Iversen · fastest of 14 · top 5 within 0.8s	1:50.258Greg Gyann · fastest of 13 · top 5 within 0.4s	149.4Robert Iversen	-7.430squal -5.358s	93.7%qual 95.3%
11 rule changes (SRF: 1, F5: 1, P2: 9)4 engine · 3 weight · 2 induction · 1 tyres & wheels · 1 othershowhide 2019-10-01 P2 Update Engine Table Line E notes #27414engine 2019-08-31 F5 Request for Weight Increase for Motorcycle Powered Cars #27214weight +25 lbs 2019-08-31 P2 Update P2 Engine Table spec lines to reflect 3/1/2019 #27254engine 2019-07-01 P2 E&O Transmissions #27006tyres & wheels 2019-07-01 SRF SRF Dash Windscreen Kit #27028other 2019-06-01 P2 Request to restrict all cars #26246weight 2019-03-01 P2 Change Engine Table Lines B.1 & B.5 #25777engine 2019-03-01 P2 Change Line A.1 restrictor size #26429induction 2019-01-01 P2 Request to Allow 1345cc Hayabusa Engines for Spec Line P2 Cars #25595engine 2019-01-01 P2 Change CN inlet restrictor implementation date #25816induction 2019-01-01 P2 Clarify Honda K20A-FD2 parts requirement #25950weight
	Sonoma Raceway Runoffs 20182018-10-10	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						1:41.807Jeff Jorgenson · fastest of 5 · top 5 within 6.6s	1:42.491David Lapham · fastest of 5 · top 5 within 9.5s	113.3David Lapham	+11.302squal +13.195s	112.4%qual 114.9%	1:28.784Tim Day Jr · fastest of 17 · top 5 within 5.0s	1:32.071Chuck Bona · fastest of 18 · top 5 within 0.9s	144.4Tim Day Jr	+0.882squal +0.172s	101.0%qual 100.2%
No rule changes on record between these events
	Indianapolis Motor Speedway Runoffs 20172017-09-25	1:33.746Gary Hickman · fastest of 18 · top 5 within 3.3s	1:33.702Alex Mayer · fastest of 17 · top 5 within 3.0s		1:51.573Thomas Kirchman · fastest of 50 · top 5 within 2.8s	1:53.769Todd Harris · fastest of 45 · top 5 within 0.2s		+20.067squal +17.827s	121.4%qual 119.0%	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		+9.158squal +9.390s	109.8%qual 110.0%	1:31.826Jeff Shafer · fastest of 26 · top 5 within 4.9s	1:32.481Jeff Shafer · fastest of 24 · top 5 within 3.8s		-1.221squal -1.920s	98.7%qual 98.0%
No rule changes on record between these events
	Mid-Ohio Sports Car Course Runoffs 20162016-09-19	1:19.886Alex Mayer · fastest of 10 · top 5 within 1.5s	1:21.015Jeremy Hill · fastest of 10 · top 5 within 1.2s		1:37.344Mike Miserendino · fastest of 27 · top 5 within 0.8s	1:37.621Todd Harris · fastest of 27 · top 5 within 0.6s		+16.606squal +17.458s	120.5%qual 121.9%	1:28.528Calvin Stewart · fastest of 14 · top 5 within 3.9s	1:29.853Steven Thompson · fastest of 12 · top 5 within 4.5s		+8.838squal +8.642s	110.9%qual 110.8%	1:20.188Jeff Shafer · fastest of 18 · top 5 within 4.0s	1:20.904Jeff Shafer · fastest of 16 · top 5 within 2.2s		-0.111squal +0.302s	99.9%qual 100.4%
No rule changes on record between these events
	Daytona International Speedway Runoffs 20152015-09-21	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		2:14.306Cliff White · fastest of 39 · top 5 within 1.2s	2:16.700Cliff White · fastest of 38 · top 5 within 0.5s		+25.084squal +23.595s	122.5%qual 121.3%	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		+11.682squal +11.113s	110.5%qual 110.0%	1:51.825Chris Farrell · fastest of 17 · top 5 within 3.6s	1:52.355Jeff Shafer · fastest of 17 · top 5 within 2.8s		+0.739squal +1.114s	100.7%qual 101.0%

By track

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