BoP Lab / Classes / SRF
SRF vs FB vs FM 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.
Closest to the field: SRF 100.0% of SRF Cliff White, Daytona International Speedway Runoffs 2015 race · FB 81.7% of SRF J R Osborne, Daytona International Speedway Runoffs 2015 race · FM 86.3% of SRF Joseph Burton-Harris, Daytona International Speedway Runoffs 2015 race
| Event | SRF | FB | FM | FE2 | ||||||||||||||||
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| 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 | 2:12.326Franklin 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)2 engine · 1 cars added · 1 wording · SRF rain/brake light part number and GCR section reference corrected for original roll hoop mounting. · SRF3 spark plugs limited to NGK LTR7IX-11 P/N G301041 only; washers and sealing rings prohibited. · FE and FE2 Enterprise bubble tail part WM138014 now allowed; FE2 must use this configuration only. · SRF3 adds HD Oil Cooler P/N G1148500 option alongside standard P/N G480503, no fan permitted.show
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| 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)1 wording · 2 other · FE2 allows pre-approved driver safety and comfort seat and control modifications for drivers with disabilities, per logbook. · SRF drivers with disabilities may modify seat and controls for safety and comfort with SCCA approval, noted in logbook, for that driver only. · SRF SADEV-SRF3 6-speed sequential transmission: effective date clarified to 1 April 2025 onward.show
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| 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)2 suspension & brakes · 1 tyres & wheels · 4 wording · 3 other · SRF3 air filter rule removes K&N RC-9160 option, specifies Weems P/N WM301020 only. · SRF Wilwood vented rotor minimum thickness increases to 13.25mm, 0.522 inches. · SRF3 Hoosier decal placement changed from four logos on nose and tail to three logos on sides and center front. · FE and SRF protest fee rules redirected to GCR section 8.3.1.D for fees and procedure. · SRF Hoosier contingency decal requirement reduced from four decals in specific locations to three decals with simplified placement. · SRF wet tyres: front P185/60R13 H20 or W2 and rear P205/60R13 H20 or W2 removed; front P185/65R13 W2 and rear P205/60R13 W2 now required. Hoosier decal placement specified. · SRF rain/brake light must be Super Bright LEDs Inc. P/N PT-STRB-R24; secondary filament must connect to rain light switch. · SRF brake light must be Super Bright LEDs Inc. P/N PT-STRB-R24, with SCCA Enterprises P/N 180427A pigtail and strobing rain light kit. · SRF adds mandatory front brake ducts 12–36 inches, throttle pedal heel-toe extension, braided stainless flex lines, camber limit 5.0 degrees, radiator opening height 3½ ± ½ inches, rear shift cable clamp P/N WM302007A. · SRF radiator options expanded: Enterprises P/N 480465 with baffle 480464, 480466, or Automotive 1R698 and CU698 allowed if cross-reference equivalent.show
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| 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 engine · SRF wet front tyre changes to Hoosier P/N 46100 P185/60R13 H20 or W2 with 2.5" ground clearance. · SRF front W2 rain tyre Hoosier part number changes from 46100 to 46101 P185/65R13. · SRF removes 1985 Renault Alliance solid front rotor option; restrictor sizes decrease 1mm for newer Kawasaki and multi-brand engines; minimum weights increase to 1100 lbs.show
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| 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 wording · 2 other · SRF tire rule wording clarified: tires must be run as delivered. · SRF brake rotor minimum thickness reduced from 13.25 mm to 12.20 mm; seals and air filter specs clarified. · SRF wet tyres front P185/65R13 W2 option added; air box clarified as-delivered; SRF3 restrictor plate G301048 mandatory Jan 1 2022; P2 motorcycle engines up to 1005cc with 35mm restrictor, 2009+ stock 1075 lbs, 2008 stock 1025 lbs, modifie…show
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| 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)1 cars added · 1 engine · 1 tyres & wheels · 2 wording · 1 other · SRF wet tyres add Hoosier W2 option alongside existing H20 from October 4, 2021. · SRF adds SADEV-SRF3 6-speed sequential transmission option with ratios 3.0–0.92:1 and 3.20 final drive. · SRF seal requirements clarified: seals now must be on driveline components in designated locations; unsealed components removed and inspected by CSR or Enterprises rather than engine shipped for testing. · SRF3 alternator pulley specified as P/N G902130 or G902130A, minimum 12oz. · SRF and SRF3 mandatory identification revised: removed Ford Performance and Blue Oval decals, added Hoosier logo placement. · SRF rear springs limited to P/N 280390 only, previous part numbers no longer allowed; ground clearance wording clarified.show
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| 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 weight · 1 tyres & wheels · 4 wording · FE2 oil cooler rule clarified: Setrab 50-625-7612 or any cooler with max core 13 inches wide by 6.5 inches high allowed. · SRF Penske shock P/N 280396 bump stop P/N 280407 becomes mandatory, maximum one per shock, effective 05/01/2020. · SRF rain and brake rule supersedes GCR 9.3.32.B.2 effective 1/1/2024 through 12/31/2024. · FE minimum weight rises to 1270 lbs; FE2 minimum weight rises to 1270 lbs; new spring options added; tire warmers prohibited. · SRF adds tire warmer prohibition and specifies Hoosier dry and wet tire part numbers. · SRF front nose weight minimum reduced from 35 to 32 lbs. · SRF2 becomes Regional Only; SRF3 nomenclature changed from GEN3 to Ford 1.6L conversion; SRF and SRF3 no longer compete together for points.show
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| Virginia International Raceway Runoffs 20192019-10-05 | 1:54.469Pete Frost · only car | 1:57.688Pete Frost · only car | 145.9Pete Frost | 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 | 1:51.062Liam 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 aero · SRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102.show
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| 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 | 1:37.598Bryce 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 | 1:35.040Flinn 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 | 1:33.746Gary Hickman · fastest of 18 · top 5 within 3.3s | 1:33.702Alex Mayer · fastest of 17 · top 5 within 3.0s | -20.067squal -17.827s | 82.4%qual 84.0% | 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% | ||||||||||
| 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 | 1:19.886Alex Mayer · fastest of 10 · top 5 within 1.5s | 1:21.015Jeremy Hill · fastest of 10 · top 5 within 1.2s | -16.606squal -17.458s | 83.0%qual 82.1% | 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% | ||||||||||
| 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 | 1:50.711J R Osborne · fastest of 20 · top 5 within 1.1s | 1:51.616J R Osborne · fastest of 19 · top 5 within 2.1s | -25.084squal -23.595s | 81.7%qual 82.4% | 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% | ||||||||||
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.