BoP Lab / Classes / SRF
SRF vs F5 vs SMX 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 · F5 90.2% of SRF Matthew Strand, Daytona International Speedway Runoffs 2015 race
| Event | SRF | F5 | SMX | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Qual best | Race best | Trap | Qual best | Race best | Trap | vs SRF | % of SRF | Qual best | Race best | Trap | vs SRF | % of SRF | |||
| Road America Runoffs 20262026-09-28 | 2:36.472Skyler Cottrell · fastest of 21 · top 5 within 0.4s+0.240s (+0.15%) | 2:36.414Cam Ebben · fastest of 21 · top 5 within 1.1s-0.677s (-0.43%) | 128.4Christian Hoagland-0.6 mph (-0.5%) | ||||||||||||
| Road America Runoffs 20252025-09-29 | 2:36.232Cam Ebben · fastest of 20 · top 5 within 0.2s+0.581s (+0.37%) | 2:37.091Michael Tinis · fastest of 19 · top 5 within 0.3s+0.813s (+0.52%) | 129.1Camden Gruber-0.4 mph (-0.3%) | ||||||||||||
7 rule changes (SRF: 2, SMX: 5)1 tyres & wheels · 1 wording · 5 othershow
| |||||||||||||||
| Road America Runoffs 20242024-10-01 | 2:35.651Ethan Lampe · fastest of 23 · top 5 within 0.7s | 2:36.278Ethan Jacobs · fastest of 22 · top 5 within 0.7s | 129.5Michael Borden | ||||||||||||
14 rule changes (SRF: 10, SMX: 4)4 suspension & brakes · 3 tyres & wheels · 1 engine · 1 weight · 2 wording · 3 othershow
| |||||||||||||||
| Virginia International Raceway Runoffs 20232023-09-23 | 2:11.435Nathan Nicholson · fastest of 18 · top 5 within 0.6s | 2:12.616Noah Harmon · fastest of 16 · top 5 within 0.1s | 127.8Noah Harmon | ||||||||||||
3 rule changes (SRF: 3)2 tyres & wheels · 1 suspension & brakesshow | |||||||||||||||
| 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%) | ||||||||||||
9 rule changes (SRF: 3, F5: 6)2 engine · 2 induction · 1 suspension & brakes · 1 tyres & wheels · 1 weight · 2 othershow
| |||||||||||||||
| 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 | ||||||||||||
9 rule changes (SRF: 6, F5: 3)3 engine · 2 tyres & wheels · 1 suspension & brakes · 1 weight · 1 wording · 1 othershow
| |||||||||||||||
| 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 | ||||||||||||
11 rule changes (SRF: 5, F5: 6)2 engine · 2 suspension & brakes · 1 induction · 1 tyres & wheels · 1 weight · 4 othershow
| |||||||||||||||
| 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 | ||||||||||||
| 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 | ||||||||||||
| 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 | 1:43.136Wiley Clinton McMahan · fastest of 38 · top 5 within 1.4s | 1:42.860Wiley Clinton McMahan · fastest of 37 · top 5 within 1.6s | -10.909squal -8.437s | 90.4%qual 92.4% | |||||||||
| 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 | 1:28.528Calvin Stewart · fastest of 14 · top 5 within 3.9s | 1:29.853Steven Thompson · fastest of 12 · top 5 within 4.5s | -7.768squal -8.816s | 92.0%qual 90.9% | |||||||||
| 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 | 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 | -13.402squal -12.482s | 90.2%qual 90.7% | |||||||||
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.