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BoP Lab / Classes / STU

STU vs FF vs F5 pace at every track

Lap times across years say as much about the weather as the class. % of STU is each class's best lap as a share of STU'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)
AS+B-Spec+EP+vsF5×FA+FC+FE2+vsFF×FP+FV+FX+GT1+GT2+GTX+HP+P+P2+SM+SMX+SRF3+STL+STU×T1+T2+T3+T4+Show 50 inactive classes
Series
Reference · what % is measured against
Tracks · untick to narrow

Closest to the field: STU 100.0% of STU Eric Heinrich, Daytona International Speedway Runoffs 2015 race · FF 90.8% of STU Jonathan Kotyk, Virginia International Raceway Runoffs 2022 race · F5 93.1% of STU Sven de Vries, Virginia International Raceway Runoffs 2022 race

1:402:002:2026 rule changes between Runoffs 2018 and Runoffs 201926 ▾27 rule changes between Runoffs 2019 and Runoffs 202027 ▾18 rule changes between Runoffs 2020 and Runoffs 202118 ▾27 rule changes between Runoffs 2021 and Runoffs 202227 ▾4 rule changes between Runoffs 2022 and Runoffs 20234 ▾6 rule changes between Runoffs 2023 and Runoffs 20246 ▾22 rule changes between Runoffs 2024 and Runoffs 202522 ▾17 rule changes between Runoffs 2025 and Runoffs 202617 ▾STU race best at Runoffs 2015: 2:06.756 (Eric Heinrich)STU race best at Runoffs 2016: 1:34.597 (Cameron Maugeri)STU race best at Runoffs 2017: 1:49.387 (Rob Huffmaster)STU race best at Runoffs 2018: 1:46.514 (Kevin Boehm)STU race best at Runoffs 2019: 2:00.483 (Kevin Boehm)STU race best at Runoffs 2020: 2:28.410 (Anthony Geraci)STU race best at Runoffs 2021: 1:47.441 (Joe Moser)STU race best at Runoffs 2022: 2:32.357 (Mark Liller)STU race best at Runoffs 2023: 2:02.302 (Mark Liller)STU race best at Runoffs 2024: 2:25.824 (Thomas Noble)STU race best at Runoffs 2025: 2:24.497 (Chip Herr)STU race best at Runoffs 2026: 2:26.416 (Richard Astacio)STU qualifying best at Runoffs 2015: 2:05.494 (Eric Heinrich)STU qualifying best at Runoffs 2016: 1:32.738 (Joe Moser)STU qualifying best at Runoffs 2017: 1:48.921 (Rob Huffmaster)Off the chart: STU qualifying best at Runoffs 2018: 1:19.234 (Franklin Church)STU qualifying best at Runoffs 2019: 1:59.948 (Kevin Boehm)STU qualifying best at Runoffs 2020: 2:27.883 (David Fiorelli)STU qualifying best at Runoffs 2021: 1:47.078 (Joe Moser)STU qualifying best at Runoffs 2022: 2:00.615 (Johan Schwartz)STU qualifying best at Runoffs 2023: 2:00.389 (Johan Schwartz)STU qualifying best at Runoffs 2024: 2:26.227 (Thomas Noble)STU qualifying best at Runoffs 2025: 2:23.083 (Peter Cunningham)STU qualifying best at Runoffs 2026: 2:24.912 (Richard Astacio)FF race best at Runoffs 2015: 2:03.383 (Rick Payne)FF race best at Runoffs 2016: 1:30.133 (Neil Verhagen)FF race best at Runoffs 2017: 1:44.524 (Jonathon Kotyk)FF race best at Runoffs 2018: 1:42.049 (Jonathon Kotyk)FF race best at Runoffs 2019: 2:20.474 (Jonathan Kotyk)FF race best at Runoffs 2020: 2:24.268 (Jeffrey Bartz)FF race best at Runoffs 2021: 1:55.676 (Jonathan Kotyk)FF race best at Runoffs 2022: 2:18.358 (Jonathan Kotyk)FF race best at Runoffs 2023: 2:00.583 (Jonathan Kotyk)FF race best at Runoffs 2024: 2:22.057 (Sebastian Mateo Naranjo)FF race best at Runoffs 2025: 2:25.541 (Calvin Kautz)FF race best at Runoffs 2026: 2:23.686 (Nathan Down)FF qualifying best at Runoffs 2015: 2:02.489 (Tim Kautz)FF qualifying best at Runoffs 2016: 1:29.213 (Neil Verhagen)FF qualifying best at Runoffs 2017: 1:44.601 (Zach Holden)FF qualifying best at Runoffs 2018: 1:41.612 (Jonathon Kotyk)FF qualifying best at Runoffs 2019: 1:59.563 (Tyler O'Connor)FF qualifying best at Runoffs 2020: 2:22.916 (Simon Sikes)FF qualifying best at Runoffs 2021: 1:44.359 (Jonathan Kotyk)FF qualifying best at Runoffs 2022: 1:59.215 (Jonathan Kotyk)FF qualifying best at Runoffs 2023: 1:59.249 (Nolan Allaer)FF qualifying best at Runoffs 2024: 2:22.552 (Calvin Kautz)FF qualifying best at Runoffs 2025: 2:24.905 (Jonathan Kotyk)FF qualifying best at Runoffs 2026: 2:23.047 (David Ybarra)F5 race best at Runoffs 2015: 2:03.298 (Matthew Strand)F5 race best at Runoffs 2016: 1:29.853 (Steven Thompson)F5 race best at Runoffs 2017: 1:42.860 (Wiley Clinton McMahan)F5 race best at Runoffs 2018: 1:42.491 (David Lapham)F5 race best at Runoffs 2019: 1:57.572 (Wiley Mcmahan)F5 race best at Runoffs 2020: 2:21.391 (James Weida)F5 race best at Runoffs 2021: 1:43.140 (Sven de Vries)F5 race best at Runoffs 2022: 2:21.862 (Sven de Vries)F5 qualifying best at Runoffs 2015: 2:01.824 (W. Clint McMahan)F5 qualifying best at Runoffs 2016: 1:28.528 (Calvin Stewart)F5 qualifying best at Runoffs 2017: 1:43.136 (Wiley Clinton McMahan)F5 qualifying best at Runoffs 2018: 1:41.807 (Jeff Jorgenson)F5 qualifying best at Runoffs 2019: 1:57.361 (Wiley Mcmahan)F5 qualifying best at Runoffs 2020: 2:20.954 (Calvin Stewart)F5 qualifying best at Runoffs 2021: 1:42.619 (Ryan Mayfield)F5 qualifying best at Runoffs 2022: 1:57.689 (James Weida)Daytona International Speedway · Runoffs 2015R2015Mid-Ohio Sports Car Course · Runoffs 2016R2016Indianapolis Motor Speedway · Runoffs 2017R2017Sonoma Raceway · Runoffs 2018R2018Virginia International Raceway · Runoffs 2019R2019Road America · Runoffs 2020R2020Indianapolis Motor Speedway · Runoffs 2021R2021Virginia International Raceway · Runoffs 2022R2022Virginia International Raceway · Runoffs 2023R2023Road America · Runoffs 2024R2024Road America · Runoffs 2025R2025Road America · Runoffs 2026R2026
STUFFF5solid race · dashed qualifying · slower is lower
95%100%105%110%115%26 rule changes between Runoffs 2018 and Runoffs 201926 ▾27 rule changes between Runoffs 2019 and Runoffs 202027 ▾18 rule changes between Runoffs 2020 and Runoffs 202118 ▾27 rule changes between Runoffs 2021 and Runoffs 202227 ▾4 rule changes between Runoffs 2022 and Runoffs 20234 ▾6 rule changes between Runoffs 2023 and Runoffs 20246 ▾22 rule changes between Runoffs 2024 and Runoffs 202522 ▾17 rule changes between Runoffs 2025 and Runoffs 202617 ▾STU race best at Runoffs 2015: 100.0% of STU's (Eric Heinrich)STU race best at Runoffs 2016: 100.0% of STU's (Cameron Maugeri)STU race best at Runoffs 2017: 100.0% of STU's (Rob Huffmaster)STU race best at Runoffs 2018: 100.0% of STU's (Kevin Boehm)STU race best at Runoffs 2019: 100.0% of STU's (Kevin Boehm)STU race best at Runoffs 2020: 100.0% of STU's (Anthony Geraci)STU race best at Runoffs 2021: 100.0% of STU's (Joe Moser)STU race best at Runoffs 2022: 100.0% of STU's (Mark Liller)STU race best at Runoffs 2023: 100.0% of STU's (Mark Liller)STU race best at Runoffs 2024: 100.0% of STU's (Thomas Noble)STU race best at Runoffs 2025: 100.0% of STU's (Chip Herr)STU race best at Runoffs 2026: 100.0% of STU's (Richard Astacio)STU qualifying best at Runoffs 2015: 100.0% of STU's (Eric Heinrich)STU qualifying best at Runoffs 2016: 100.0% of STU's (Joe Moser)STU qualifying best at Runoffs 2017: 100.0% of STU's (Rob Huffmaster)STU qualifying best at Runoffs 2018: 100.0% of STU's (Franklin Church)STU qualifying best at Runoffs 2019: 100.0% of STU's (Kevin Boehm)STU qualifying best at Runoffs 2020: 100.0% of STU's (David Fiorelli)STU qualifying best at Runoffs 2021: 100.0% of STU's (Joe Moser)STU qualifying best at Runoffs 2022: 100.0% of STU's (Johan Schwartz)STU qualifying best at Runoffs 2023: 100.0% of STU's (Johan Schwartz)STU qualifying best at Runoffs 2024: 100.0% of STU's (Thomas Noble)STU qualifying best at Runoffs 2025: 100.0% of STU's (Peter Cunningham)STU qualifying best at Runoffs 2026: 100.0% of STU's (Richard Astacio)FF race best at Runoffs 2015: 97.3% of STU's (Rick Payne)FF race best at Runoffs 2016: 95.3% of STU's (Neil Verhagen)FF race best at Runoffs 2017: 95.6% of STU's (Jonathon Kotyk)FF race best at Runoffs 2018: 95.8% of STU's (Jonathon Kotyk)FF race best at Runoffs 2019: 116.6% of STU's (Jonathan Kotyk)FF race best at Runoffs 2020: 97.2% of STU's (Jeffrey Bartz)FF race best at Runoffs 2021: 107.7% of STU's (Jonathan Kotyk)Off the chart: FF race best at Runoffs 2022: 90.8% of STU's (Jonathan Kotyk)FF race best at Runoffs 2023: 98.6% of STU's (Jonathan Kotyk)FF race best at Runoffs 2024: 97.4% of STU's (Sebastian Mateo Naranjo)FF race best at Runoffs 2025: 100.7% of STU's (Calvin Kautz)FF race best at Runoffs 2026: 98.1% of STU's (Nathan Down)FF qualifying best at Runoffs 2015: 97.6% of STU's (Tim Kautz)FF qualifying best at Runoffs 2016: 96.2% of STU's (Neil Verhagen)FF qualifying best at Runoffs 2017: 96.0% of STU's (Zach Holden)Off the chart: FF qualifying best at Runoffs 2018: 128.2% of STU's (Jonathon Kotyk)FF qualifying best at Runoffs 2019: 99.7% of STU's (Tyler O'Connor)FF qualifying best at Runoffs 2020: 96.6% of STU's (Simon Sikes)FF qualifying best at Runoffs 2021: 97.5% of STU's (Jonathan Kotyk)FF qualifying best at Runoffs 2022: 98.8% of STU's (Jonathan Kotyk)FF qualifying best at Runoffs 2023: 99.1% of STU's (Nolan Allaer)FF qualifying best at Runoffs 2024: 97.5% of STU's (Calvin Kautz)FF qualifying best at Runoffs 2025: 101.3% of STU's (Jonathan Kotyk)FF qualifying best at Runoffs 2026: 98.7% of STU's (David Ybarra)F5 race best at Runoffs 2015: 97.3% of STU's (Matthew Strand)F5 race best at Runoffs 2016: 95.0% of STU's (Steven Thompson)F5 race best at Runoffs 2017: 94.0% of STU's (Wiley Clinton McMahan)F5 race best at Runoffs 2018: 96.2% of STU's (David Lapham)F5 race best at Runoffs 2019: 97.6% of STU's (Wiley Mcmahan)F5 race best at Runoffs 2020: 95.3% of STU's (James Weida)F5 race best at Runoffs 2021: 96.0% of STU's (Sven de Vries)F5 race best at Runoffs 2022: 93.1% of STU's (Sven de Vries)F5 qualifying best at Runoffs 2015: 97.1% of STU's (W. Clint McMahan)F5 qualifying best at Runoffs 2016: 95.5% of STU's (Calvin Stewart)F5 qualifying best at Runoffs 2017: 94.7% of STU's (Wiley Clinton McMahan)Off the chart: F5 qualifying best at Runoffs 2018: 128.5% of STU's (Jeff Jorgenson)F5 qualifying best at Runoffs 2019: 97.8% of STU's (Wiley Mcmahan)F5 qualifying best at Runoffs 2020: 95.3% of STU's (Calvin Stewart)F5 qualifying best at Runoffs 2021: 95.8% of STU's (Ryan Mayfield)F5 qualifying best at Runoffs 2022: 97.6% of STU's (James Weida)Daytona International Speedway · Runoffs 2015R2015Mid-Ohio Sports Car Course · Runoffs 2016R2016Indianapolis Motor Speedway · Runoffs 2017R2017Sonoma Raceway · Runoffs 2018R2018Virginia International Raceway · Runoffs 2019R2019Road America · Runoffs 2020R2020Indianapolis Motor Speedway · Runoffs 2021R2021Virginia International Raceway · Runoffs 2022R2022Virginia International Raceway · Runoffs 2023R2023Road America · Runoffs 2024R2024Road America · Runoffs 2025R2025Road America · Runoffs 2026R2026
STUFFF5solid race · dashed qualifying · each class's best lap as a share of STU's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker
EventSTUFFF5
Qual best Race best Trap Qual best Race best Trap vs STU % of STU Qual best Race best Trap vs STU % of STU 
Road America Runoffs 20262026-09-282:24.912Richard Astacio · fastest of 17 · top 5 within 2.6s+1.829s (+1.28%)2:26.416Richard Astacio · fastest of 16 · top 5 within 1.5s+1.919s (+1.33%)145.1Hugh Stewart+0.8 mph (+0.5%)2:23.047David Ybarra · fastest of 20 · top 5 within 1.4s-1.858s (-1.28%)2:23.686Nathan Down · fastest of 20 · top 5 within 1.6s-1.855s (-1.27%)138.9Tazio Stefanelli+0.5 mph (+0.3%)-2.730squal -1.865s98.1%qual 98.7%
17 rule changes (STU: 15, FF: 2)7 weight · 4 induction · 4 tyres & wheels · 2 engineshowhide
  • STU Wheel and tire requirements for GT3U #40679tyres & wheels
  • FF Clarification in FF Kent 1600 Compression Ratio Paragraph #40293engine
  • STU 9” Wheels #40433tyres & wheels
  • STU Weight adjustment to former GT3U cars #40474weight
  • STU Request to allow BMW M50B20TU engine in STU #40202engine
  • STU Calculating Weight #40224weight
  • STU Turbo Restrictor Size Increase Request #40008induction
  • STU GT86 Cups Car in STU #40028weight
  • STU Mazda Rx-8 Renesis - Streetported Variant & Added Weight #39785weight
  • STU Eliminate 33 and 34 mm TIRs #39872weight
  • STU Fab 9 Racing Intake Manifold in STU #39767induction
  • FF Formula F Alternative Tire Rule Proposed Clarifications #39281tyres & wheels
  • STU Request for Permission on Aftermarket Turbo Kit and Intake #39529induction
  • STU Turbo Inlet Restrictor Table #38961induction
  • STU 275 Tire Rule #38983tyres & wheels
  • STU STU Honda Engine weight penalty #39375weight
  • STU Non-Homologated Engine Swaps - Specifically K24A2 w/ Honda CRZ #38746weight
Road America Runoffs 20252025-09-292:23.083Peter Cunningham · fastest of 16 · top 5 within 2.6s-3.144s (-2.15%)2:24.497Chip Herr · fastest of 15 · top 5 within 3.8s-1.327s (-0.91%)144.3Chip Herr-1.0 mph (-0.7%)2:24.905Jonathan Kotyk · fastest of 17 · top 5 within 1.1s+2.353s (+1.65%)2:25.541Calvin Kautz · fastest of 16 · top 5 within 0.5s+3.484s (+2.45%)138.4Tazio Stefanelli-2.3 mph (-1.6%)+1.044squal +1.822s100.7%qual 101.3%
22 rule changes (STU: 18, FF: 4)9 weight · 5 tyres & wheels · 3 engine · 1 cars added · 1 induction · 1 wording · 2 othershowhide
  • STU Lotus Weight Reduction E&O #38919weight
  • STU STU-TCR Adjustments #38723weight
  • STU Lotus Weight Reduction #38772weight -50 lbs
  • STU 2.8-3.2L N/A Engine Allowances #38007engine
  • STU 2006-2015 Mazda Miata Intake Manifold #38422induction
  • STU Requesting Approval of the JDM Honda h23a #38489cars added
  • FF Page 228, FF tire rule 9.1.1.10.e #38251tyres & wheels
  • STU Wheel Size Inconsistency #38018tyres & wheels
  • STU Table C: STU-GT3U Clarification #38268weight
  • FF Formula F Proposal to Invite Older Cars Via a Tire Rule Change #37802tyres & wheels
  • STU BMW N54/N55 Engine Allowance Follow Up #37447engine
  • STU STU Mini Cooper pulley size clarification re: letter #36980 #37717wording
  • STU Question About a Weight Modifier #37782weight
  • STU Increase Minimum Weight #37919weight +100 lbs
  • STU Audi 1.8t Wagon STU Table B #36685weight
  • STU Merger GT3 to STU #37486other
  • STU GT3 TCR Tire allowance #37494tyres & wheels
  • STU Request to Remove Miata Hubs from General category #37138tyres & wheels
  • STU BMW N54/N55 Engine Allowance #37146engine
  • FF Change FF/FC Weight with Sequential Gearbox #36651weight
  • FF Alternative Oversize Honda Fit Pistons #37064weight
  • STU R53 15% Pulley Request #36980other
Road America Runoffs 20242024-10-012:26.227Thomas Noble · fastest of 18 · top 5 within 2.3s-1.656s (-1.12%)2:25.824Thomas Noble · fastest of 17 · top 5 within 2.4s-2.586s (-1.74%)145.3Thomas Noble+1.1 mph (+0.8%)2:22.552Calvin Kautz · fastest of 13 · top 5 within 1.1s-0.364s (-0.25%)2:22.057Sebastian Mateo Naranjo · fastest of 13 · top 5 within 0.6s-2.211s (-1.53%)140.7Calvin Kautz+2.6 mph (+1.9%)-3.767squal -3.675s97.4%qual 97.5%
6 rule changes (STU: 4, FF: 2)1 engine · 1 induction · 1 weight · 3 othershowhide
  • FF Update to FF EGR Blanking Plate Rule #36633engine
  • STU RWD Turbo Disadvantage #36255induction
  • STU Letter #35397 addendum #35453weight
  • STU S54 Drysump #35464other
  • STU ST Electric-Assisted Steering Systems #35066other
  • FF Honda Fit Oversize Piston Rings #35305other
Virginia International Raceway Runoffs 20232023-09-232:00.389Johan Schwartz · fastest of 13 · top 5 within 2.3s-0.226s (-0.19%)2:02.302Mark Liller · fastest of 14 · top 5 within 1.6s-30.055s (-19.73%)144.0Mark Liller+0.1 mph (+0.1%)1:59.249Nolan Allaer · fastest of 8 · top 5 within 2.8s+0.034s (+0.03%)2:00.583Jonathan Kotyk · fastest of 8 · top 5 within 0.4s-17.775s (-12.85%)138.4Calvin Kautz+0.1 mph (+0.1%)-1.719squal -1.140s98.6%qual 99.1%
4 rule changes (STU: 3, FF: 1)1 cars added · 1 engine · 1 induction · 1 weightshowhide
  • STU 2022 Toyota GR Cup for STU #34449cars added
  • STU Alternate OEM Miata Intake Manifold #33827induction
  • FF Add Fast Forward Part Numbers for Honda Fit Engine #33752engine
  • STU E&O STU NA Weight Chart. #33737weight
Virginia International Raceway Runoffs 20222022-09-242:00.615Johan Schwartz · fastest of 21 · top 5 within 2.6s+0.667s (+0.56%)2:32.357Mark Liller · fastest of 19 · top 5 within 4.3s+31.874s (+26.46%)143.9Johan Schwartz+0.1 mph (+0.1%)1:59.215Jonathan Kotyk · fastest of 13 · top 5 within 1.2s-0.348s (-0.29%)2:18.358Jonathan Kotyk · fastest of 12 · top 5 within 2.4s-2.116s (-1.51%)138.3Tim Kautz+2.2 mph (+1.6%)-13.999squal -1.400s90.8%qual 98.8%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%)-10.495squal -2.926s93.1%qual 97.6%
27 rule changes (STU: 21, F5: 6)8 weight · 6 engine · 4 induction · 2 cars added · 1 aero · 1 tyres & wheels · 5 othershowhide
  • F5 Intake Boots Correction #33028induction
  • F5 Ensure availability of ECU for Rotax engines #32695engine
  • STU Request Mazda 13 B turbo #32668induction
  • STU Hood Vents and Intercooler Scoops #32733other
  • STU Non 4 valve weight reduction removed #32808weight
  • F5 Clarify stepped exhaust header references #32743engine
  • STU Error in new minimum weight table when combined with other text #32711weight
  • STU Redundant Language in May GCR #32713engine
  • F5 593 carb boot availability and oil pump clarification #32527induction
  • STU Opposed to the Proposed STU Weight Chart #32381weight
  • STU Clarification request for GCR 9.1.4.D.3.a Splitter Definition #32414aero
  • STU Request Adjustment to Min Weight for STU BMW E36 M3 (95-99) #31535weight -90 lbs
  • STU BMW E36 M3 Canadian (North American) S50B32 engine #31866engine
  • STU Engine Swap Origin Country #32209engine
  • STU CRX/Civic Del Sol #32214cars added
  • STU Error correction #32383weight
  • STU Single TB Weight Modifiers Add to Chart #32393weight
  • F5 E&O class name #32194other
  • STU Single TB Weight Modifiers #31449weight
  • STU Request to Remove A4 1.8t from STU Spec Line Tables #31465weight
  • STU Improved Touring Tires #32063tyres & wheels
  • STU Request Allowance for Balance Shaft Delete in STU #31434engine
  • STU Request Louvers in hood vents #31916other
  • F5 Data Box Mounting Plate #31638other
  • STU Request to Add Honda K23 Spec Line #30682cars added
  • STU RE: Aug FT letter 30682 #31060other
  • STU Throttling Device Clarification #31323induction
Indianapolis Motor Speedway Runoffs 20212021-09-251:47.078Joe Moser · fastest of 30 · top 5 within 2.0s-1.843s (-1.69%)1:47.441Joe Moser · fastest of 28 · top 5 within 1.8s-1.946s (-1.78%)146.9Kip VanSteenburg1:44.359Jonathan Kotyk · fastest of 24 · top 5 within 1.1s-0.242s (-0.23%)1:55.676Jonathan Kotyk · fastest of 23 · top 5 within 1.8s+11.152s (+10.67%)141.6Nicholas Sheppard+8.235squal -2.719s107.7%qual 97.5%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-4.301squal -4.459s96.0%qual 95.8%
18 rule changes (STU: 12, FF: 3, F5: 3)4 engine · 4 weight · 3 tyres & wheels · 1 aero · 1 cars added · 1 suspension & brakes · 3 wording · 1 othershowhide
  • F5 Clarify allowable assisted shifting systems #30871wording
  • F5 Request to correct terminology #30976tyres & wheels
  • STU STU Fender flares #30696tyres & wheels
  • STU Request weight reduction for 12A bridgeport motor in Miata #30751weight -200 lbs
  • F5 Request to Allow Rotax 593 HO Engine #30712engine
  • STU Request for Fender Flare Clarification #30375weight
  • FF Kent crankshaft clarification #30426wording
  • STU Provision for Interchangeable Engine Components Already Allowed #30342engine
  • STU ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wording
  • STU Super Touring Alternate Miata Hubs #30345tyres & wheels
  • STU Brake Component Relocation #29990suspension & brakes
  • STU Porsche PDK #30081weight
  • STU Reference Letter #29333 Proposed STU 13B Spec Line Changes #30086weight
  • STU Drive Shaft Request #30087other
  • STU 13B Rules Adjustment #29333cars added
  • FF Allow Optional Coolant Bleed Line to Correct a Known Problem #29673engine
  • FF Clarification regarding Honda LC1 ECU implementation date #29684engine
  • STU Request clarification on wing measurement #29640aero
Road America Runoffs 20202020-10-022:27.883David Fiorelli · fastest of 14 · top 5 within 4.1s2:28.410Anthony Geraci · fastest of 14 · top 5 within 3.1s144.2David Fiorelli2:22.916Simon Sikes · fastest of 14 · top 5 within 1.6s2:24.268Jeffrey Bartz · fastest of 14 · top 5 within 0.4s138.1Jeffrey Bartz-4.142squal -4.967s97.2%qual 96.6%2:20.954Calvin Stewart · fastest of 16 · top 5 within 1.8s2:21.391James Weida · fastest of 14 · top 5 within 1.5s143.2Aaron Ellis-7.019squal -6.929s95.3%qual 95.3%
27 rule changes (STU: 17, FF: 4, F5: 6)8 engine · 7 induction · 5 weight · 2 aero · 1 tyres & wheels · 4 othershowhide
  • F5 Request to Update Suzuki Engine Years for F500 #29453engine
  • STU Request for Advanced Aero Rule Wording Clarification. #29124aero
  • FF Clarification regarding Honda LC1 ECU implementation #29135engine
  • STU Minimum Weight Determination #27695weight
  • STU ST Gurney flap Wicker clarification #29012aero
  • F5 Request for Cockpit Adjustment of External Jetting Devices #28359other
  • F5 Two Stroke Motors (reply to #28359 WDYT) #28816engine
  • F5 Re letter requesting driver adjustable carb mixture #28840other
  • F5 #28359 WDYT Request for Cockpit Adjustment #28875other
  • STU Request for Alternate Intake Manifold #26514induction
  • STU Request for Addition to GT3 Approved Turbo List #27576induction
  • STU Request BoP for my Car #29004induction
  • STU Sequential Shifters in STU #29031other
  • STU Rotary Help #27833weight
  • FF E&O FF Kent Engine alternator language #28204engine
  • STU Request to approve Honda S2000 HKS supercharger #27281engine
  • STU Request BoP on the Lotus #27637weight +100 lbs
  • STU Turbo Inlet Restrictor On MK5 Volkswagen #27704induction
  • STU Honda K20C1 removal #27732induction
  • STU Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0 #27884engine
  • STU Alternate Engine for Porsche 944 #28259engine
  • FF Honda Racing HPD low cost ECU proposal #27563engine
  • FF Update rain tire designation #28443tyres & wheels
  • STU Please Modify the STU Wheel Size Rule for Clarity #27694weight
  • STU Turbo Engine Cars Base Weight #28032weight
  • F5 Change 600cc restrictor size #27883induction
  • STU Request for an electronic throttle body #27342induction
Virginia International Raceway Runoffs 20192019-10-051:59.948Kevin Boehm · fastest of 25 · top 5 within 3.5s2:00.483Kevin Boehm · fastest of 25 · top 5 within 2.5s143.8Kevin Boehm1:59.563Tyler O'Connor · fastest of 14 · top 5 within 1.4s2:20.474Jonathan Kotyk · fastest of 14 · top 5 within 6.3s136.2Derek Ketchie+19.991squal -0.385s116.6%qual 99.7%1:57.361Wiley Mcmahan · fastest of 15 · top 5 within 3.8s1:57.572Wiley Mcmahan · fastest of 15 · top 5 within 4.0s142.8Eric McRee-2.911squal -2.587s97.6%qual 97.8%
26 rule changes (STU: 22, FF: 3, F5: 1)7 induction · 6 weight · 3 aero · 3 cars added · 3 engine · 2 suspension & brakes · 1 tyres & wheels · 1 wordingshowhide
  • F5 Request for Weight Increase for Motorcycle Powered Cars #27214weight +25 lbs
  • STU Request to correct E&O advanced aerodynamics #27290aero
  • STU Remove -2mm penalty from SR20DET Nissan #26982weight
  • STU Request clarification for manifold and throttle in STU #27004induction
  • STU Request to clarify afterrmarket side skirts exhaust exit #26814suspension & brakes
  • STU Wheel Flare wording #26872tyres & wheels
  • STU Request Ride Height Clarification #26597suspension & brakes
  • STU Request to Use Japanese Mazda 13b Intake Manifold #25790induction
  • STU Request Alternate Intake for Mazda MZR In a Rear Wheel Drive App. #26352induction
  • STU E&O Suspension #26424wording
  • STU Revisit B20 VTEC #26530cars added
  • STU Move Flared Fenders to STU Advanced Aero #26564aero
  • STU TCA Civic SI E&O #26606induction
  • STU S54 Spec line #26620weight
  • STU Request to Class Assignment for 2017 Civic #24287cars added
  • STU Request to run E46 3246cc in STU #25126weight
  • STU Engine Classification for Rotary #25564engine
  • STU K24/K20 Head Swap Clarification/Amendment #25899induction
  • STU Request to Classify 12a Bridge Ported Rotary Engine #25985cars added
  • STU World Challenge Car Eligibility #26387weight
  • STU Request a phone call for discussion regarding weight #26398weight
  • STU Advanced Aero E&O #26413aero
  • FF Request for Oversize Honda Fit Pistons #25810engine
  • FF Heat Shield - Fit Intake #26102induction
  • FF Request catch cans/tanks clarification #26158engine
  • STU Request to Equalize Direct Injected Turbo Cars #24890induction
Sonoma Raceway Runoffs 20182018-10-101:19.234Franklin Church · fastest of 10 · top 5 within 21.5s1:46.514Kevin Boehm · fastest of 9 · top 5 within 7.4s103.0Franklin Church1:41.612Jonathon Kotyk · fastest of 22 · top 5 within 1.7s1:42.049Jonathon Kotyk · fastest of 22 · top 5 within 1.3s115.7Denny Renfrow-4.465squal +22.378s95.8%qual 128.2%1:41.807Jeff Jorgenson · fastest of 5 · top 5 within 6.6s1:42.491David Lapham · fastest of 5 · top 5 within 9.5s113.3David Lapham-4.023squal +22.573s96.2%qual 128.5%
No rule changes on record between these events
Indianapolis Motor Speedway Runoffs 20172017-09-251:48.921Rob Huffmaster · fastest of 34 · top 5 within 2.0s1:49.387Rob Huffmaster · fastest of 31 · top 5 within 2.4s1:44.601Zach Holden · fastest of 36 · top 5 within 1.2s1:44.524Jonathon Kotyk · fastest of 36 · top 5 within 0.5s-4.863squal -4.320s95.6%qual 96.0%1:43.136Wiley Clinton McMahan · fastest of 38 · top 5 within 1.4s1:42.860Wiley Clinton McMahan · fastest of 37 · top 5 within 1.6s-6.527squal -5.785s94.0%qual 94.7%
No rule changes on record between these events
Mid-Ohio Sports Car Course Runoffs 20162016-09-191:32.738Joe Moser · fastest of 16 · top 5 within 2.5s1:34.597Cameron Maugeri · fastest of 16 · top 5 within 0.8s1:29.213Neil Verhagen · fastest of 14 · top 5 within 2.1s1:30.133Neil Verhagen · fastest of 14 · top 5 within 1.4s-4.464squal -3.525s95.3%qual 96.2%1:28.528Calvin Stewart · fastest of 14 · top 5 within 3.9s1:29.853Steven Thompson · fastest of 12 · top 5 within 4.5s-4.744squal -4.210s95.0%qual 95.5%
No rule changes on record between these events
Daytona International Speedway Runoffs 20152015-09-212:05.494Eric Heinrich · fastest of 18 · top 5 within 4.6s2:06.756Eric Heinrich · fastest of 17 · top 5 within 3.5s2:02.489Tim Kautz · fastest of 25 · top 5 within 1.1s2:03.383Rick Payne · fastest of 22 · top 5 within 0.8s-3.373squal -3.005s97.3%qual 97.6%2:01.824W. Clint McMahan · fastest of 16 · top 5 within 3.0s2:03.298Matthew Strand · fastest of 15 · top 5 within 4.9s-3.458squal -3.670s97.3%qual 97.1%

By track

TrackEvents Typical % of STU Best Latest 
Road America4100.0%100.0%Runoffs 2020100.0%Runoffs 2026
Virginia International Raceway3100.0%100.0%Runoffs 2019100.0%Runoffs 2023
Indianapolis Motor Speedway2100.0%100.0%Runoffs 2017100.0%Runoffs 2021
Daytona International Speedway1100.0%100.0%Runoffs 2015100.0%Runoffs 2015
Mid-Ohio Sports Car Course1100.0%100.0%Runoffs 2016100.0%Runoffs 2016
Sonoma Raceway1100.0%100.0%Runoffs 2018100.0%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 STU'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.