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BoP Lab / Classes / T4

T4 vs FM vs SRF3 vs SM pace at every track

Lap times across years say as much about the weather as the class. % of T4 is each class's best lap as a share of T4'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-SpecEPFAFCFE2FFvsFM×FPFVFXGT1GT2GTXHPPP2vsSM×SMXvsSRF3×STLSTUT1T2T3T4×Show 50 inactive classes
Series
Reference · what % is measured against
Tracks · untick to narrow

Closest to the field: T4 100.0% of T4 Philip Royle, Daytona International Speedway Runoffs 2015 race · FM 85.9% of T4 Bryce Cornet, Sonoma Raceway Runoffs 2018 race · SRF3 93.9% of T4 TJ Acker, Sonoma Raceway Runoffs 2018 race · SM 95.6% of T4 Travis Wiley, Virginia International Raceway Runoffs 2022 race

1:402:002:202:4022 rule changes between Runoffs 2018 and Runoffs 201922 ▾34 rule changes between Runoffs 2019 and Runoffs 202034 ▾27 rule changes between Runoffs 2020 and Runoffs 202127 ▾33 rule changes between Runoffs 2021 and Runoffs 202233 ▾25 rule changes between Runoffs 2022 and Runoffs 202325 ▾42 rule changes between Runoffs 2023 and Runoffs 202442 ▾36 rule changes between Runoffs 2024 and Runoffs 202536 ▾30 rule changes between Runoffs 2025 and Runoffs 202630 ▾T4 race best at Runoffs 2015: 2:15.994 (Philip Royle)T4 race best at Runoffs 2016: 1:40.397 (Oscar Jackson)T4 race best at Runoffs 2017: 1:56.923 (Oscar Jackson)T4 race best at Runoffs 2018: 1:54.030 (John Heinricy)T4 race best at Runoffs 2019: 2:10.959 (Nick Leverone)T4 race best at Runoffs 2020: 2:37.881 (Chi Ho)T4 race best at Runoffs 2021: 1:55.929 (John Heinricy)T4 race best at Runoffs 2022: 2:25.443 (John Heinricy)T4 race best at Runoffs 2023: 2:11.962 (Devin Anderson)T4 race best at Runoffs 2024: 2:34.208 (Alex Lozano)T4 race best at Runoffs 2025: 2:32.633 (Alex Lozano)T4 race best at Runoffs 2026: 2:35.757 (Matt Spicuzzi)T4 qualifying best at Runoffs 2015: 2:15.886 (Philip Royle)T4 qualifying best at Runoffs 2016: 1:38.813 (Jonathan Yanca)T4 qualifying best at Runoffs 2017: 1:56.566 (Oscar Jackson)T4 qualifying best at Runoffs 2018: 1:52.339 (Gresham Wagner)T4 qualifying best at Runoffs 2019: 2:11.257 (John Heinricy)T4 qualifying best at Runoffs 2020: 2:37.403 (John Heinricy)T4 qualifying best at Runoffs 2021: 1:54.397 (Stephen Blethen)T4 qualifying best at Runoffs 2022: 2:09.577 (John Heinricy)T4 qualifying best at Runoffs 2023: 2:10.514 (Devin Anderson)T4 qualifying best at Runoffs 2024: 2:34.430 (Matt Spicuzzi)T4 qualifying best at Runoffs 2025: 2:32.956 (Matt Spicuzzi)T4 qualifying best at Runoffs 2026: 2:35.876 (Matt Spicuzzi)FM race best at Runoffs 2015: 1:58.029 (Joseph Burton-Harris)FM race best at Runoffs 2016: 1:27.922 (Jacob Loomis)FM race best at Runoffs 2017: 1:41.146 (Jarret Voorhies)FM race best at Runoffs 2018: 1:37.909 (Bryce Cornet)FM race best at Runoffs 2019: 2:15.816 (Bryce Cornet)FM qualifying best at Runoffs 2015: 1:57.804 (Joseph Burton-Harris)Off the chart: FM qualifying best at Runoffs 2016: 1:26.043 (Jacob Loomis)FM qualifying best at Runoffs 2017: 1:41.231 (Jarret Voorhies)FM qualifying best at Runoffs 2018: 1:37.598 (Bryce Cornet)FM qualifying best at Runoffs 2019: 1:55.124 (Bryce Cornet)SRF3 race best at Runoffs 2015: 2:10.215 (Chad Galloway)SRF3 race best at Runoffs 2016: 1:34.947 (Cliff White)SRF3 race best at Runoffs 2017: 1:49.782 (Tray Ayres)SRF3 race best at Runoffs 2018: 1:47.053 (TJ Acker)SRF3 race best at Runoffs 2019: 2:04.755 (Bobby Sak)SRF3 race best at Runoffs 2020: 2:31.038 (Justin Hille)SRF3 race best at Runoffs 2021: 1:50.095 (John Black)SRF3 race best at Runoffs 2022: 2:22.066 (Franklin Futrelle)SRF3 race best at Runoffs 2023: 2:04.911 (David Ogburn)SRF3 race best at Runoffs 2024: 2:28.129 (S Sandy Satullo III)SRF3 race best at Runoffs 2025: 2:29.839 (Morgan Burkhard)SRF3 race best at Runoffs 2026: 2:29.257 (Peyton Long)SRF3 qualifying best at Runoffs 2015: 2:08.557 (Kerry Jacobsen)SRF3 qualifying best at Runoffs 2016: 1:34.363 (John Black)SRF3 qualifying best at Runoffs 2017: 1:49.824 (John Black)SRF3 qualifying best at Runoffs 2018: 1:46.117 (Robeson Clay Russell)SRF3 qualifying best at Runoffs 2019: 2:04.624 (Brian Schofield)SRF3 qualifying best at Runoffs 2020: 2:29.786 (TJ Acker)SRF3 qualifying best at Runoffs 2021: 1:49.520 (Franklin Futrelle)SRF3 qualifying best at Runoffs 2022: 2:03.716 (Franklin Futrelle)SRF3 qualifying best at Runoffs 2023: 2:03.842 (Morgan Burkhard)SRF3 qualifying best at Runoffs 2024: 2:27.773 (Denny Stripling)SRF3 qualifying best at Runoffs 2025: 2:28.226 (Bobby Sak)SRF3 qualifying best at Runoffs 2026: 2:27.443 (Tyler Stephens)SM race best at Runoffs 2015: 2:24.067 (Todd Lamb)SM race best at Runoffs 2016: 1:40.764 (Michael Carter)SM race best at Runoffs 2017: 1:59.100 (Michael Gagliardo)SM race best at Runoffs 2018: 1:55.278 (Michael Carter)SM race best at Runoffs 2019: 2:16.459 (Elivan Goulart)SM race best at Runoffs 2020: 2:43.748 (Preston Pardus)SM race best at Runoffs 2021: 1:58.837 (Brian Henderson)SM race best at Runoffs 2022: 2:19.107 (Travis Wiley)SM race best at Runoffs 2023: 2:16.229 (Julian DaCosta)SM race best at Runoffs 2024: 2:41.486 (Brett Kowalski)SM race best at Runoffs 2025: 2:44.430 (Kyle Greenhill)SM race best at Runoffs 2026: 2:42.725 (Francisco Barroso)SM qualifying best at Runoffs 2015: 2:18.661 (Andrew Carbonell)SM qualifying best at Runoffs 2016: 1:40.514 (Justin Hille)SM qualifying best at Runoffs 2017: 1:58.306 (Chris Haldeman)SM qualifying best at Runoffs 2018: 1:54.355 (Ken Sutherland)SM qualifying best at Runoffs 2019: 2:14.552 (Todd Buras)SM qualifying best at Runoffs 2020: 2:42.209 (Kyle Greenhill)SM qualifying best at Runoffs 2021: 1:57.695 (Brian Henderson)SM qualifying best at Runoffs 2022: 2:14.664 (Danny Steyn)SM qualifying best at Runoffs 2023: 2:14.986 (Danny Steyn)SM qualifying best at Runoffs 2024: 2:41.106 (Ethan Goulart)SM qualifying best at Runoffs 2025: 2:43.111 (Bobby Gossett)SM qualifying best at Runoffs 2026: 2:42.173 (Brett Kowalski)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
T4FMSRF3SMsolid race · dashed qualifying · slower is lower
85%90%95%100%105%22 rule changes between Runoffs 2018 and Runoffs 201922 ▾34 rule changes between Runoffs 2019 and Runoffs 202034 ▾27 rule changes between Runoffs 2020 and Runoffs 202127 ▾33 rule changes between Runoffs 2021 and Runoffs 202233 ▾25 rule changes between Runoffs 2022 and Runoffs 202325 ▾42 rule changes between Runoffs 2023 and Runoffs 202442 ▾36 rule changes between Runoffs 2024 and Runoffs 202536 ▾30 rule changes between Runoffs 2025 and Runoffs 202630 ▾T4 race best at Runoffs 2015: 100.0% of T4's (Philip Royle)T4 race best at Runoffs 2016: 100.0% of T4's (Oscar Jackson)T4 race best at Runoffs 2017: 100.0% of T4's (Oscar Jackson)T4 race best at Runoffs 2018: 100.0% of T4's (John Heinricy)T4 race best at Runoffs 2019: 100.0% of T4's (Nick Leverone)T4 race best at Runoffs 2020: 100.0% of T4's (Chi Ho)T4 race best at Runoffs 2021: 100.0% of T4's (John Heinricy)T4 race best at Runoffs 2022: 100.0% of T4's (John Heinricy)T4 race best at Runoffs 2023: 100.0% of T4's (Devin Anderson)T4 race best at Runoffs 2024: 100.0% of T4's (Alex Lozano)T4 race best at Runoffs 2025: 100.0% of T4's (Alex Lozano)T4 race best at Runoffs 2026: 100.0% of T4's (Matt Spicuzzi)T4 qualifying best at Runoffs 2015: 100.0% of T4's (Philip Royle)T4 qualifying best at Runoffs 2016: 100.0% of T4's (Jonathan Yanca)T4 qualifying best at Runoffs 2017: 100.0% of T4's (Oscar Jackson)T4 qualifying best at Runoffs 2018: 100.0% of T4's (Gresham Wagner)T4 qualifying best at Runoffs 2019: 100.0% of T4's (John Heinricy)T4 qualifying best at Runoffs 2020: 100.0% of T4's (John Heinricy)T4 qualifying best at Runoffs 2021: 100.0% of T4's (Stephen Blethen)T4 qualifying best at Runoffs 2022: 100.0% of T4's (John Heinricy)T4 qualifying best at Runoffs 2023: 100.0% of T4's (Devin Anderson)T4 qualifying best at Runoffs 2024: 100.0% of T4's (Matt Spicuzzi)T4 qualifying best at Runoffs 2025: 100.0% of T4's (Matt Spicuzzi)T4 qualifying best at Runoffs 2026: 100.0% of T4's (Matt Spicuzzi)FM race best at Runoffs 2015: 86.8% of T4's (Joseph Burton-Harris)FM race best at Runoffs 2016: 87.6% of T4's (Jacob Loomis)FM race best at Runoffs 2017: 86.5% of T4's (Jarret Voorhies)FM race best at Runoffs 2018: 85.9% of T4's (Bryce Cornet)FM race best at Runoffs 2019: 103.7% of T4's (Bryce Cornet)FM qualifying best at Runoffs 2015: 86.7% of T4's (Joseph Burton-Harris)FM qualifying best at Runoffs 2016: 87.1% of T4's (Jacob Loomis)FM qualifying best at Runoffs 2017: 86.8% of T4's (Jarret Voorhies)FM qualifying best at Runoffs 2018: 86.9% of T4's (Bryce Cornet)FM qualifying best at Runoffs 2019: 87.7% of T4's (Bryce Cornet)SRF3 race best at Runoffs 2015: 95.8% of T4's (Chad Galloway)SRF3 race best at Runoffs 2016: 94.6% of T4's (Cliff White)SRF3 race best at Runoffs 2017: 93.9% of T4's (Tray Ayres)SRF3 race best at Runoffs 2018: 93.9% of T4's (TJ Acker)SRF3 race best at Runoffs 2019: 95.3% of T4's (Bobby Sak)SRF3 race best at Runoffs 2020: 95.7% of T4's (Justin Hille)SRF3 race best at Runoffs 2021: 95.0% of T4's (John Black)SRF3 race best at Runoffs 2022: 97.7% of T4's (Franklin Futrelle)SRF3 race best at Runoffs 2023: 94.7% of T4's (David Ogburn)SRF3 race best at Runoffs 2024: 96.1% of T4's (S Sandy Satullo III)SRF3 race best at Runoffs 2025: 98.2% of T4's (Morgan Burkhard)SRF3 race best at Runoffs 2026: 95.8% of T4's (Peyton Long)SRF3 qualifying best at Runoffs 2015: 94.6% of T4's (Kerry Jacobsen)SRF3 qualifying best at Runoffs 2016: 95.5% of T4's (John Black)SRF3 qualifying best at Runoffs 2017: 94.2% of T4's (John Black)SRF3 qualifying best at Runoffs 2018: 94.5% of T4's (Robeson Clay Russell)SRF3 qualifying best at Runoffs 2019: 94.9% of T4's (Brian Schofield)SRF3 qualifying best at Runoffs 2020: 95.2% of T4's (TJ Acker)SRF3 qualifying best at Runoffs 2021: 95.7% of T4's (Franklin Futrelle)SRF3 qualifying best at Runoffs 2022: 95.5% of T4's (Franklin Futrelle)SRF3 qualifying best at Runoffs 2023: 94.9% of T4's (Morgan Burkhard)SRF3 qualifying best at Runoffs 2024: 95.7% of T4's (Denny Stripling)SRF3 qualifying best at Runoffs 2025: 96.9% of T4's (Bobby Sak)SRF3 qualifying best at Runoffs 2026: 94.6% of T4's (Tyler Stephens)SM race best at Runoffs 2015: 105.9% of T4's (Todd Lamb)SM race best at Runoffs 2016: 100.4% of T4's (Michael Carter)SM race best at Runoffs 2017: 101.9% of T4's (Michael Gagliardo)SM race best at Runoffs 2018: 101.1% of T4's (Michael Carter)SM race best at Runoffs 2019: 104.2% of T4's (Elivan Goulart)SM race best at Runoffs 2020: 103.7% of T4's (Preston Pardus)SM race best at Runoffs 2021: 102.5% of T4's (Brian Henderson)SM race best at Runoffs 2022: 95.6% of T4's (Travis Wiley)SM race best at Runoffs 2023: 103.2% of T4's (Julian DaCosta)SM race best at Runoffs 2024: 104.7% of T4's (Brett Kowalski)SM race best at Runoffs 2025: 107.7% of T4's (Kyle Greenhill)SM race best at Runoffs 2026: 104.5% of T4's (Francisco Barroso)SM qualifying best at Runoffs 2015: 102.0% of T4's (Andrew Carbonell)SM qualifying best at Runoffs 2016: 101.7% of T4's (Justin Hille)SM qualifying best at Runoffs 2017: 101.5% of T4's (Chris Haldeman)SM qualifying best at Runoffs 2018: 101.8% of T4's (Ken Sutherland)SM qualifying best at Runoffs 2019: 102.5% of T4's (Todd Buras)SM qualifying best at Runoffs 2020: 103.1% of T4's (Kyle Greenhill)SM qualifying best at Runoffs 2021: 102.9% of T4's (Brian Henderson)SM qualifying best at Runoffs 2022: 103.9% of T4's (Danny Steyn)SM qualifying best at Runoffs 2023: 103.4% of T4's (Danny Steyn)SM qualifying best at Runoffs 2024: 104.3% of T4's (Ethan Goulart)SM qualifying best at Runoffs 2025: 106.6% of T4's (Bobby Gossett)SM qualifying best at Runoffs 2026: 104.0% of T4's (Brett Kowalski)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
T4FMSRF3SMsolid race · dashed qualifying · each class's best lap as a share of T4's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker
EventT4FMSRF3SM
Qual best Race best Trap Qual best Race best Trap vs T4 % of T4 Qual best Race best Trap vs T4 % of T4 Qual best Race best Trap vs T4 % of T4 
Road America Runoffs 20262026-09-282:35.876Matt Spicuzzi · fastest of 12 · top 5 within 2.4s+2.920s (+1.91%)2:35.757Matt Spicuzzi · fastest of 12 · top 5 within 2.7s+3.124s (+2.05%)127.6Matt Spicuzzi-6.0 mph (-4.5%)2:27.443Tyler Stephens · fastest of 44 · top 5 within 0.3s-0.783s (-0.53%)2:29.257Peyton Long · fastest of 42 · top 5 within 0.3s-0.582s (-0.39%)134.1Bobby Sak+0.4 mph (+0.3%)-6.500squal -8.433s95.8%qual 94.6%2:42.173Brett Kowalski · fastest of 34 · top 5 within 0.3s-0.938s (-0.58%)2:42.725Francisco Barroso · fastest of 35 · top 5 within 0.2s-1.705s (-1.04%)119.6Wyatt Couch+0.3 mph (+0.3%)+6.968squal +6.297s104.5%qual 104.0%
30 rule changes (T4: 26, SRF3: 2, SM: 2)5 cars added · 5 suspension & brakes · 5 weight · 3 induction · 2 tyres & wheels · 1 removed · 1 wording · 8 othershowhide
  • T4 02-06 R53 Mini Cooper Hotchkins Rear Camber Arms #40677suspension & brakes
  • T4 Is it time? #40653cars added
  • T4 Combine T4 BRZ/86/FRS generations #40656weight
  • SM Rear Toe Link #40271other
  • T4 Dodge Neon DOHC Weight #40329weight
  • T4 SPB In T4 #39973other
  • T4 02-06 Mini Cooper S #40106weight -50 lbs
  • T4 02-06 Mini Cooper S Fuel #40107other
  • T4 Shock error #40176suspension & brakes
  • T4 Max Tire Sizes #40183tyres & wheels
  • T4 2003 Honda Civic Si Classification #39999cars added
  • SM Part Number Change Request #39914wording
  • T4 16-24 ND MX5 T4 #39934suspension & brakes
  • SRF3 SRF3 Spark Plugs #39899other
  • T4 ND MX-5 Spec Line Rewrite Request #39802weight -100 lbs
  • T4 4.0 Mustang spec line cleanup #39831induction
  • T4 T4 and T3 Feedback #39230removed
  • T4 T4 Mustang 4.0 #39489induction
  • T4 Allow Alt Bushing Material in Toe Links #39607suspension & brakes
  • T4 Alternate Placement of Fuse Panel and Electronics Request #39370other
  • T4 Clarify T4 Brake Rotor Allowance #39503suspension & brakes
  • T4 Classing 1995-99 Dodge Neon SOHC #39285cars added
  • T4 02-06 Mini Cooper Gear Ratios #38966other
  • T4 Reinstatement of the 2005-2010 Cobalt into T4 #38987cars added
  • T4 Request to Classify Mercedes C230K #39080cars added
  • T4 ND Gearset Request for T4 #39166other
  • T4 E&O wheel size on ND #39168tyres & wheels
  • T4 ND Spec Lines Wrong PT#'s #39170weight
  • T4 Touring 4 Post-Runoffs BOP Adjustments and Changes #39251induction -100 lbs
  • SRF3 Add HD Oil Cooler #38979other
Road America Runoffs 20252025-09-292:32.956Matt Spicuzzi · fastest of 10 · top 5 within 3.8s-1.474s (-0.95%)2:32.633Alex Lozano · fastest of 10 · top 5 within 4.3s-1.575s (-1.02%)133.7Alex Lozano+4.4 mph (+3.4%)2:28.226Bobby Sak · fastest of 43 · top 5 within 0.6s+0.453s (+0.31%)2:29.839Morgan Burkhard · fastest of 42 · top 5 within 0.3s+1.710s (+1.15%)133.7Bobby Sak-1.5 mph (-1.1%)-2.794squal -4.730s98.2%qual 96.9%2:43.111Bobby Gossett · fastest of 32 · top 5 within 0.3s+2.005s (+1.24%)2:44.430Kyle Greenhill · fastest of 28 · top 5 within 0.3s+2.944s (+1.82%)119.3Francisco Barroso-0.6 mph (-0.5%)+11.797squal +10.155s107.7%qual 106.6%
36 rule changes (T4: 29, SRF3: 3, SM: 4)7 weight · 5 cars added · 5 tyres & wheels · 2 engine · 2 suspension & brakes · 1 aero · 1 induction · 3 wording · 10 othershowhide
  • SRF3 SRF Rule Updates #38853weight
  • T4 Incorrect Touring Heading #38451wording
  • T4 Allow B-Spec cars to run in T4 #38439other
  • SM SMX Data Submission - Penalties #38248other
  • SM SMX Penaly Clarification updated language #38337wording
  • T4 T4 Mustang #38059weight -100 lbs
  • T4 SSC tire allowance #38216tyres & wheels
  • SM Clarify Tire Marking Regs #38005tyres & wheels
  • T4 Correct Ring and Pinion Ratio to T3, Sorry I Mean T4 3.7 V6 Stang #38041wording
  • T4 T4 Mustang #38058aero
  • SRF3 Driver Safety & Comfort #37966other
  • SRF3 Update SADEV transmission specs #37992other
  • T4 Ford Mustang V6 (05-14) #37516other
  • T4 Request to Classify Club Spec in Appropriate Touring Classes #37523cars added
  • T4 Remove spec lines that have expired #37269induction
  • T4 2016-2018 Mazda Miata MX5 #37085weight -75 lbs
  • SM E&O SMX Regs 9.1.7.1.D.5.u-.w #37070other
  • T4 Redundant Verbiage Regarding Mustang Spec Lines for Driveshaft #36484suspension & brakes
  • T4 R53 Mini Cooper S Weight Reduction Request #36612weight
  • T4 Allowable Wheel Offset #36855tyres & wheels
  • T4 Fuel Emissions Components #37076engine
  • T4 2019-2024 Mazda 3 for T4 #37077cars added
  • T4 fix brake wording #37129suspension & brakes
  • T4 Evaporative emissions systems #37130engine
  • T4 Allow Spec MX5 upgrade kit for 2009-11 RX8 S2 Transmision #37140other
  • T4 Move Spec Boxster to T4 #37158cars added
  • T4 3.7 Mustangs to T4 #37188cars added
  • T4 BMW 320i Spec Line #37204other
  • T4 MX5 2006-2015 NC Help #37221other
  • T4 Classification for a 2005 Cadillac CTS 3.6 liter 6 speed manual #37224cars added
  • T4 Civic SI in T4 #37248weight -50 lbs
  • T4 2006-2015 T4 NC Mx5 spec line #37278weight
  • T4 ND MX-5 wheel allowance #37279tyres & wheels
  • T4 T4 BOP #37281weight +75 lbs
  • T4 Allow 7.5 #37286tyres & wheels
  • T4 Bop Request 06-11 Honda Civic Si #37013other
Road America Runoffs 20242024-10-012:34.430Matt Spicuzzi · fastest of 15 · top 5 within 1.8s-2.973s (-1.89%)2:34.208Alex Lozano · fastest of 14 · top 5 within 2.2s-3.673s (-2.33%)129.3Alex Lozano-0.9 mph (-0.7%)2:27.773Denny Stripling · fastest of 57 · top 5 within 0.3s-2.013s (-1.34%)2:28.129S Sandy Satullo III · fastest of 52 · top 5 within 0.7s-2.909s (-1.93%)135.2Denny Stripling+3.4 mph (+2.6%)-6.079squal -6.657s96.1%qual 95.7%2:41.106Ethan Goulart · fastest of 49 · top 5 within 0.5s-1.103s (-0.68%)2:41.486Brett Kowalski · fastest of 43 · top 5 within 0.3s-2.262s (-1.38%)119.9Alex Bertagnoli-1.4 mph (-1.2%)+7.278squal +6.676s104.7%qual 104.3%
42 rule changes (T4: 28, SRF3: 10, SM: 4)11 weight · 9 suspension & brakes · 3 induction · 3 tyres & wheels · 2 aero · 2 cars added · 2 engine · 1 removed · 1 wording · 8 othershowhide
  • SRF3 Update SRF3 Air Filter Rule #36681other
  • SRF3 Update SRF Brake Rotor Thickness #36687suspension & brakes
  • SRF3 Hoosier Tire Decal Placement #36739tyres & wheels
  • SM SMX Camera Rule Correction #36496wording
  • SM AIM ECU Protocol #36556engine
  • SM OE versus OEM Definitons #36608other
  • SM Shifter Bushing #36611suspension & brakes
  • SRF3 Update to Letter 36619 with new Hoosier Contingency Decal Info #36624tyres & wheels
  • SRF3 Update Rain Tire Rule and Hoosier Decal Placement #36436tyres & wheels
  • T4 T4 Camaro V6 weight reduction #36232weight
  • T4 BOP adjustment for ND MX5s #36345weight -50 lbs
  • T4 Mustang T2/T3 #35877other
  • T4 Homologation of car to T4 #36030cars added
  • T4 T2-T4 Driveshaft Mistake...? #36050weight
  • T4 MINI Cooper S Spec Lines Corrections. #36086removed
  • T4 Allow Removal of Sound Tubes #36130induction
  • T4 B8/8.5 Audi S4 T3 and T2 #36195cars added
  • SRF3 SRF3 Alternator Pulley Update In #36095weight
  • T4 Allow OEM Front Spoiler 06-08 Miata in T4 #35941aero
  • T4 T4 Mustang Weight Reduction In T4 Spec #36051weight -50 lbs
  • T4 R53 Mini Cooper S spec line request In #36056suspension & brakes
  • T4 Allow T4 and T3 RX8 to Disable/Remove Factory Oil Inj. #35761engine
  • T4 2023 ND2 Miata Classification and Allowances #35837weight
  • T4 Errors and Omissions for 06-09 VW Rabbit Rotor #35851suspension & brakes
  • T4 Driveshafts #35916weight
  • T4 GCR ERROR - letter not properly applied to GCR #35999weight
  • T4 Corrections to T4 RX8 Spec line #35767aero
  • T4 Reorganize Spec Lines #35375induction
  • T4 Allow any 400lb rear spring in the RX8 #35433suspension & brakes
  • T4 370Z Brake Rotor Size Correction #35487suspension & brakes
  • T4 More Car Lightening Stuff #35319weight
  • T4 ND Missed Items #35352other
  • T4 Inclusion of B-C spec cars in T4 #35374other
  • T4 T2-T4 Set expiration dates on spec lines #35378induction
  • SRF3 Update SRF Rain / Brake Rule #34706suspension & brakes
  • SRF3 Update SRF Brake Light Rule v1 #34853suspension & brakes
  • SRF3 SRF / SRF3 Rule Updates #35268weight
  • T4 Mazda MX-5 ND1 Spec Line Request #34232weight +50 lbs
  • T4 BRZ/FRS/86 Spring Allowance #35038suspension & brakes
  • T4 TSX Allowance #35219other
  • T4 Requested Update of Model Years of 370Z #35231other
  • SRF3 SRF Radiator Rule Update #34805other
Virginia International Raceway Runoffs 20232023-09-232:10.514Devin Anderson · fastest of 24 · top 5 within 0.5s+0.937s (+0.72%)2:11.962Devin Anderson · fastest of 23 · top 5 within 0.1s-13.481s (-9.27%)127.8Raymond Blethen+0.5 mph (+0.4%)2:03.842Morgan Burkhard · fastest of 40 · top 5 within 0.2s+0.126s (+0.10%)2:04.911David Ogburn · fastest of 39 · top 5 within 0.3s-17.155s (-12.08%)134.5Bobby Sak+0.1 mph (+0.0%)-7.051squal -6.672s94.7%qual 94.9%2:14.986Danny Steyn · fastest of 52 · top 5 within 0.1s+0.322s (+0.24%)2:16.229Julian DaCosta · fastest of 46 · top 5 within 0.3s-2.878s (-2.07%)120.3Jim Drago+1.1 mph (+0.9%)+4.267squal +4.472s103.2%qual 103.4%
25 rule changes (T4: 20, SRF3: 4, SM: 1)7 weight · 5 suspension & brakes · 4 tyres & wheels · 2 cars added · 1 induction · 2 wording · 4 othershowhide
  • T4 Inclusion of similar car. (CLK 320) #34626other
  • T4 Rules Clarification for Mazda RX8 Spec Line #34395weight
  • T4 rule book corrections #34437wording
  • T4 Ride Height Correction for the T3 Solstice. #34615suspension & brakes
  • T4 2002-2006 Mini Cooper S R53 Spec Line Request #34336weight -50 lbs
  • SRF3 Hoosier SRF Wet Front Tire Rule Update #34189tyres & wheels
  • T4 05-06 Mini Wheel Weight #34112weight
  • T4 06-09 VW Rabbit #34153induction
  • T4 96-01 Audi a4 2.8 Spring Rate #34217suspension & brakes
  • SRF3 Update SRF Front W2 Rain Tire Part Number #34118tyres & wheels
  • T4 Request to Classify 2004-2008 Acura TSX in T4 #33590cars added
  • T4 T4 Mustang Brakes/Swaybar #34036suspension & brakes
  • SRF3 Update SRF Brake Rule #33469suspension & brakes
  • SRF3 Update SRF Bodywork Fitment Rule #33765tyres & wheels
  • T4 BMW 320I intercooler #33762other
  • T4 2019-2021 Mazda MX5 ND2 #32027cars added
  • T4 Mustang OEM Grill Request #33333other
  • T4 Mazda OEM LSD was letter 32655 typo #33666wording
  • SM BOP for NB1 and NB2 #32309weight
  • T4 Allowable Springs and Sway Bars for 06-11 Civic si Spec Line #33294suspension & brakes
  • T4 Touring (T2-T5) Category #33617tyres & wheels
  • T4 ENO 9.1.9.2.D.1.e.1.a. #33651other
  • T4 T4 mustang #32789weight -25 lbs
  • T4 Mazda OEM LSD was letter 32655 #32933weight -25 lbs
  • T4 Another 2022 BRZ/86 T3 request #32945weight +225 lbs
Virginia International Raceway Runoffs 20222022-09-242:09.577John Heinricy · fastest of 18 · top 5 within 0.7s-1.680s (-1.28%)2:25.443John Heinricy · fastest of 18 · top 5 within 2.5s+14.484s (+11.06%)127.4Nick Leverone-1.5 mph (-1.2%)2:03.716Franklin Futrelle · fastest of 44 · top 5 within 0.6s-0.908s (-0.73%)2:22.066Franklin Futrelle · fastest of 40 · top 5 within 1.2s+17.311s (+13.88%)134.5David Ogburn+2.1 mph (+1.6%)-3.377squal -5.861s97.7%qual 95.5%2:14.664Danny Steyn · fastest of 60 · top 5 within 0.2s+0.112s (+0.08%)2:19.107Travis Wiley · fastest of 58 · top 5 within 0.9s+2.648s (+1.94%)119.2Jonathan Neudorf-0.6 mph (-0.5%)-6.336squal +5.087s95.6%qual 103.9%
33 rule changes (T4: 29, SRF3: 3, SM: 1)10 suspension & brakes · 6 tyres & wheels · 5 weight · 2 cars added · 2 engine · 1 induction · 1 removed · 2 wording · 4 othershowhide
  • T4 04-09 Mazda3 Balance Shaft Delete Kit #32795other
  • SRF3 SRF Tire Rule Update #32614tyres & wheels
  • SRF3 Brake, seal, and air filter clarifications #32670suspension & brakes
  • T4 Request Wider Wheels for Hyundai Tiburon #32536tyres & wheels
  • T4 Request to Add Spec Line for 2004-2009 Mazda3 i 2.0 #32395weight
  • T4 Request Alternate Front & Rear Strut/Shock Top Hats #32452suspension & brakes
  • SM Update GCR Section 9.1.7.3.A.1. #32217suspension & brakes
  • T4 Request to Allow the Use of Aftermarket ECU's in Touring #31067engine
  • T4 Request JWT BSR Kit for 02-06 Nissan Sentra SE-R/Spec V #31685other
  • T4 Please Confirm Touring 4 (98-00) BMW 323 is E46 generation #31972other
  • T4 RX-8 Spring Part Numbers (E&O) #32151suspension & brakes
  • T4 04-09 Mazda3 Tire Limit Clarification #32249tyres & wheels
  • T4 Shock Part Number Errors & Omissions #32252suspension & brakes
  • T4 Update Solo Spec Coupe to latest '20 specs for Road Racing #32262other
  • T4 Request 2016 Mazda MX5 springs #32265suspension & brakes
  • T4 Reply to letter #31486/29879 T2-T4 Grill openings #31935suspension & brakes
  • T4 BRZ vs BRZ TS #32022tyres & wheels
  • T4 MX-5 Durability Detailed #31102weight
  • T4 Request Allowances for 2005 - 2010 Mustang #31624wording
  • T4 Reply to letter 29879 T2-T4 Grill Openings #31486suspension & brakes
  • T4 Please Adjust 98-00 BMW 323 Min Weight to Reflect Current Class #31595weight -200 lbs
  • T4 Consolidate 12-13 and 14-15 Honda Civic Si spec lines for T4 #31596removed
  • T4 Request to clarify radiator hoses #31682wording
  • T4 Clarify Permitted/Allowed #31743suspension & brakes
  • T4 Correct RSX wording #31746tyres & wheels
  • T4 Camaro #31751suspension & brakes
  • SRF3 Three Updates to SRF Rules #31523weight
  • T4 Nissan Sentra SE-R Spec. V #30958cars added
  • T4 Mazda RX-8 Spec Line Suspension Parts #31113induction
  • T4 Diverter Valve Plunger Upgrade #31307engine
  • T4 Adjust Honda FWD in T4 to encourage more Drivetrain Diversity #31472tyres & wheels
  • T4 Touring 4 BOP adjustments for 2022 #31482weight -175 lbs
  • T4 Request to Classify 2014 VW Jetta 1.8t TSI #30436cars added
Indianapolis Motor Speedway Runoffs 20212021-09-251:54.397Stephen Blethen · fastest of 47 · top 5 within 0.9s-2.169s (-1.86%)1:55.929John Heinricy · fastest of 46 · top 5 within 1.0s-0.994s (-0.85%)127.3Alexander Schefer1:49.520Franklin Futrelle · fastest of 84 · top 5 within 0.5s-0.304s (-0.28%)1:50.095John Black · fastest of 82 · top 5 within 0.2s+0.313s (+0.29%)132.1Matthew Horst-5.834squal -4.877s95.0%qual 95.7%1:57.695Brian Henderson · fastest of 90 · top 5 within 0.5s-0.611s (-0.52%)1:58.837Brian Henderson · fastest of 88 · top 5 within 0.3s-0.263s (-0.22%)119.8Kyle Greenhill+2.908squal +3.298s102.5%qual 102.9%
27 rule changes (T4: 20, SRF3: 6, SM: 1)4 tyres & wheels · 4 weight · 3 suspension & brakes · 2 cars added · 2 engine · 2 induction · 2 wording · 8 othershowhide
  • SRF3 SRF Wet Tires #30849tyres & wheels
  • SRF3 SADEV-SRF3 Transmission #30926other
  • SRF3 SRF Update Maintenance, Repairs and Seals #30961engine
  • T4 Wrong Part Number on 320i Spec Line #30645wording
  • SRF3 SRF3 Alternator Pulley #30684weight
  • T4 Civic Type R Brake Rotors #29817suspension & brakes
  • T4 Mini Cooper Spec Line Anomalies #30478weight
  • T4 Request CAI Mustang in T4 #30562induction
  • SM Updates - Obsolete Parts & BOP Parts #30438other
  • T4 Request consistency review in GCR #30263other
  • SRF3 Mandatory identification: #30223engine
  • T4 E & O T4 Mustang Wheels #30245tyres & wheels
  • T4 2021 Toyota Supra #29567cars added
  • T4 06-15 MX-5 Durability #29781other
  • T4 Request for Update to T4 Spec Line for Chevrolet Sonic (2011-) #29838induction
  • T4 NC MX-5 06-15 Part Number updates for 2021 #29921weight
  • T4 BMW Z4 2.5L (03-05) Spec Line #30037weight -50 lbs
  • T4 Sway Bars for T4 2016+ MX5 Mazda #30063suspension & brakes
  • T4 Change part numbers on BRZ, FRS lines in T4 #30104wording
  • T4 T4 Mustang Axle Ratio and Wheels #30149tyres & wheels
  • T4 Request to Classify BMW M2 CS #29523cars added
  • T4 Allow the SpecMX-5 Update Kit Into Touring 4 for the MX-5 #29681other
  • T4 Request Mustang 8.8” rear axle replacement #29860other
  • T4 Cap year range on all 86s #29908other
  • SRF3 SRF Shocks, Springs and Ride Height. #29688suspension & brakes
  • T4 Alfa Romeo 4C Launch Edition #29531other
  • T4 Post Runoffs Feedback for T4 #29752tyres & wheels -50 lbs
Road America Runoffs 20202020-10-022:37.403John Heinricy · fastest of 20 · top 5 within 2.5s2:37.881Chi Ho · fastest of 19 · top 5 within 1.6s130.2Chi Ho2:29.786TJ Acker · fastest of 59 · top 5 within 0.5s2:31.038Justin Hille · fastest of 55 · top 5 within 0.2s131.9Charles Russell Turner-6.843squal -7.617s95.7%qual 95.2%2:42.209Kyle Greenhill · fastest of 77 · top 5 within 0.5s2:43.748Preston Pardus · fastest of 75 · top 5 within 1.0s121.3Kyle Greenhill+5.867squal +4.806s103.7%qual 103.1%
34 rule changes (T4: 25, SRF3: 7, SM: 2)9 suspension & brakes · 5 weight · 3 cars added · 3 tyres & wheels · 2 engine · 1 aero · 4 wording · 7 othershowhide
  • SM Radiator E&O Clarifications #29294engine
  • SM Modifications to prevent failures of Rear Brake Caliper Pin #28953suspension & brakes
  • T4 Scion FRS Solo Spec Coupe Gear Ratio #29021other
  • T4 T4 RX8 bodywork clarification #28941aero
  • T4 2006-2015 MX-5 Clarification #28942tyres & wheels
  • T4 Request to Add a Vehicle to the Roster (contd.) #27698other
  • SRF3 SRF Shocks #28791suspension & brakes
  • T4 Request to Classify 2004 Mercedes Benz 320 CLK #27663cars added
  • SRF3 Update Bump Stop Rule #28712suspension & brakes
  • SRF3 SRF Bump Stop Correction #27019suspension & brakes
  • T4 Request to change allowed header part # for T4 06-15 Miata #28223wording
  • T4 Z3M Roadster Weight #28437weight
  • T4 Request for 12-13 and 14-15 Honda Civic Springs #27848suspension & brakes
  • T4 Request to Clarify T4 05-10 Mustang Spring Allowance #27899suspension & brakes
  • T4 Request to Allow Brake Upgrade on T4 Mustang #27329suspension & brakes
  • T4 Please Switch the Solstice GXP as Specified in T2, to T3 #27413weight -50 lbs
  • T4 Request to Classify all Mazda RX8 Models in T3/T4 #27606cars added
  • T4 Request for 2014-2018 Mazda 3 GT Brakes #27659suspension & brakes
  • T4 Request to allow aftermarket OEM coolant expansion tank #27763engine
  • T4 Request to allow aftermarket OEM power steering reservoir #27764wording
  • T4 Request for Factory Installed Wings on Subaru BRZ #27831other
  • T4 Request for Replacement Clutches #27892other
  • T4 Request to Classify Chevy Sonic 1.4 In T4 #27906cars added
  • T4 Weight Change Request for 1999 Mazda Miata #28129weight -50 lbs
  • T4 Clarification of On-Board Fire System for T2 #27183wording
  • T4 Mustang Ecoboost and GT Transmission #27439other
  • T4 BRZ/FRS/86 Tire Size in T4 #27660tyres & wheels
  • T4 NC MX5 2006-2015 Spec Adjustment Request #27739weight -75 lbs
  • T4 T4 RX8 Classification Error #27902wording
  • T4 Request to add Toyota 86 GT to Spec Line #27910other
  • SRF3 SRF Rain / Brake Rule - BoD approved as follows #34958suspension & brakes
  • SRF3 SRF Tire Warmer Rule #27622tyres & wheels
  • SRF3 SRF / SRF3 Nose Weight Reduction #27706weight
  • SRF3 SRF / SRF3 Majors & Regional Class Updates #27723other
Virginia International Raceway Runoffs 20192019-10-052:11.257John Heinricy · fastest of 25 · top 5 within 0.2s2:10.959Nick Leverone · fastest of 25 · top 5 within 0.6s128.9Tommy Boileau1:55.124Bryce Cornet · fastest of 8 · top 5 within 2.3s2:15.816Bryce Cornet · fastest of 8 · top 5 within 4.9s135.7Bryce Cornet+4.857squal -16.133s103.7%qual 87.7%2:04.624Brian Schofield · fastest of 54 · top 5 within 0.6s2:04.755Bobby Sak · fastest of 53 · top 5 within 0.3s132.4Bobby Sak-6.204squal -6.633s95.3%qual 94.9%2:14.552Todd Buras · fastest of 60 · top 5 within 0.2s2:16.459Elivan Goulart · fastest of 56 · top 5 within 0.4s119.8Jim Drago+5.500squal +3.295s104.2%qual 102.5%
22 rule changes (T4: 15, SRF3: 3, SM: 4)5 weight · 4 suspension & brakes · 2 cars added · 2 engine · 2 tyres & wheels · 1 induction · 3 wording · 3 othershowhide
  • T4 Request spare tire/wheel clarification #27012tyres & wheels
  • T4 Research E&O Mazda MX5 #27112weight
  • SRF3 SRF Dash Windscreen Kit #27028other
  • T4 MR2 Spyder Year Correction #26936wording
  • SRF3 New SRF Sectional Nose Rule Addition #26914other
  • T4 Request to allow piggy back ECU on 2000 Mazda Protégé #26085engine
  • T4 Request helper spring as optional #26678suspension & brakes
  • SRF3 SRF Brakes and Shock Rule Changes #26629suspension & brakes
  • T4 Request to classify 2000 - 2001 BMW 323 #25096cars added
  • SM Request to allow aftermarket fuel filters. #26370wording
  • T4 Correct Mazda MX-5 Hard Top Notes #26137weight
  • T4 Consider opening class rules to allow any thermostat #26187wording
  • T4 Cap 2016 Mazda Miata year at 2018 #26388other
  • SM Request 99-00 replacement Wire harnesses #25602engine
  • SM Organize and Clarify 9.1.7.C.1.o. #25913weight
  • SM Strike Tire Tread Language #26123tyres & wheels
  • T4 2012-2015 Honda Civic Si Performance Request #26129suspension & brakes
  • T4 Errors, Omissions, and Updates (Various) #22414weight
  • T4 Request for Adjustments to fiat 124 specline #25371induction
  • T4 Add Clarification to Spec Car Classifications Vehicle Spec #25774weight
  • T4 Clarify Subframe Bushings Permitted for T2-T4 #25800suspension & brakes
  • T4 Consider Solo SSC cross over classification into T4 #25802cars added
Sonoma Raceway Runoffs 20182018-10-101:52.339Gresham Wagner · fastest of 12 · top 5 within 1.1s1:54.030John Heinricy · fastest of 12 · top 5 within 0.2s106.0Ross Murray1:37.598Bryce Cornet · fastest of 13 · top 5 within 0.9s1:37.909Bryce Cornet · fastest of 12 · top 5 within 1.3s124.1Melvin David Kemper Jr-16.121squal -14.741s85.9%qual 86.9%1:46.117Robeson Clay Russell · fastest of 36 · top 5 within 0.5s1:47.053TJ Acker · fastest of 35 · top 5 within 0.2s110.2Steve Fogg-6.977squal -6.222s93.9%qual 94.5%1:54.355Ken Sutherland · fastest of 48 · top 5 within 0.7s1:55.278Michael Carter · fastest of 48 · top 5 within 0.3s102.2Danny Steyn+1.248squal +2.016s101.1%qual 101.8%
No rule changes on record between these events
Indianapolis Motor Speedway Runoffs 20172017-09-251:56.566Oscar Jackson · fastest of 40 · top 5 within 0.6s1:56.923Oscar Jackson · fastest of 38 · top 5 within 1.1s1:41.231Jarret Voorhies · fastest of 16 · top 5 within 1.7s1:41.146Jarret Voorhies · fastest of 16 · top 5 within 1.2s-15.777squal -15.335s86.5%qual 86.8%1:49.824John Black · fastest of 101 · top 5 within 0.5s1:49.782Tray Ayres · fastest of 94 · top 5 within 0.4s-7.141squal -6.742s93.9%qual 94.2%1:58.306Chris Haldeman · fastest of 86 · top 5 within 0.5s1:59.100Michael Gagliardo · fastest of 83 · top 5 within 0.6s+2.177squal +1.740s101.9%qual 101.5%
No rule changes on record between these events
Mid-Ohio Sports Car Course Runoffs 20162016-09-191:38.813Jonathan Yanca · fastest of 34 · top 5 within 2.0s1:40.397Oscar Jackson · fastest of 32 · top 5 within 0.8s1:26.043Jacob Loomis · fastest of 8 · top 5 within 3.1s1:27.922Jacob Loomis · fastest of 8 · top 5 within 2.7s-12.475squal -12.770s87.6%qual 87.1%1:34.363John Black · fastest of 41 · top 5 within 0.5s1:34.947Cliff White · fastest of 39 · top 5 within 0.3s-5.450squal -4.450s94.6%qual 95.5%1:40.514Justin Hille · fastest of 45 · top 5 within 0.3s1:40.764Michael Carter · fastest of 44 · top 5 within 0.3s+0.367squal +1.701s100.4%qual 101.7%
No rule changes on record between these events
Daytona International Speedway Runoffs 20152015-09-212:15.886Philip Royle · fastest of 22 · top 5 within 0.9s2:15.994Philip Royle · fastest of 20 · top 5 within 1.6s1:57.804Joseph Burton-Harris · fastest of 10 · top 5 within 2.3s1:58.029Joseph Burton-Harris · fastest of 10 · top 5 within 1.7s-17.965squal -18.082s86.8%qual 86.7%2:08.557Kerry Jacobsen · fastest of 29 · top 5 within 1.1s2:10.215Chad Galloway · fastest of 29 · top 5 within 0.3s-5.779squal -7.329s95.8%qual 94.6%2:18.661Andrew Carbonell · fastest of 62 · top 5 within 0.6s2:24.067Todd Lamb · fastest of 59 · top 5 within 0.8s+8.073squal +2.775s105.9%qual 102.0%

By track

TrackEvents Typical % of T4 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 T4'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.