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BoP Lab / Classes / T4

T4 vs GTL 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)
AS+B-Spec+EP+FA+FC+FE2+FF+FP+FV+FX+GT1+GT2+vsGTL×GTX+HP+P+P2+vsSM×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: T4 100.0% of T4 Philip Royle, Daytona International Speedway Runoffs 2015 race · GTL 94.7% of T4 Christopher Bovis, Indianapolis Motor Speedway Runoffs 2017 qualifying · SM 95.6% of T4 Travis Wiley, Virginia International Raceway Runoffs 2022 race

1:402:002:202:4032 rule changes between Runoffs 2018 and Runoffs 201932 ▾44 rule changes between Runoffs 2019 and Runoffs 202044 ▾29 rule changes between Runoffs 2020 and Runoffs 202129 ▾33 rule changes between Runoffs 2021 and Runoffs 202233 ▾28 rule changes between Runoffs 2022 and Runoffs 202328 ▾48 rule changes between Runoffs 2023 and Runoffs 202448 ▾36 rule changes between Runoffs 2024 and Runoffs 202536 ▾29 rule changes between Runoffs 2025 and Runoffs 202629 ▾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)GTL race best at Runoffs 2015: 2:13.564 (Jim Dentici)GTL race best at Runoffs 2016: 1:35.912 (Kyle Disque)GTL race best at Runoffs 2017: 1:52.068 (Christopher Bovis)GTL race best at Runoffs 2018: 1:49.458 (Troy Ermish)GTL race best at Runoffs 2019: 2:07.837 (Bill Ball)GTL race best at Runoffs 2020: 2:31.601 (Peter Shadowen)GTL race best at Runoffs 2021: 1:51.952 (Scott Twomey)GTL race best at Runoffs 2022: 2:21.180 (Michael Lewis)GTL race best at Runoffs 2023: 2:11.277 (Graham Fuller)GTL race best at Runoffs 2024: 2:30.844 (Chris Bovis)GTL qualifying best at Runoffs 2015: 2:11.387 (Jim Dentici)GTL qualifying best at Runoffs 2016: 1:35.377 (Wilson Wright)GTL qualifying best at Runoffs 2017: 1:50.331 (Christopher Bovis)GTL qualifying best at Runoffs 2018: 1:47.885 (Troy Ermish)GTL qualifying best at Runoffs 2019: 2:06.997 (Peter Shadowen)GTL qualifying best at Runoffs 2020: 2:31.943 (Chris Bovis)GTL qualifying best at Runoffs 2021: 1:51.819 (Christopher Bovis)GTL qualifying best at Runoffs 2022: 2:07.789 (Peter Shadowen)GTL qualifying best at Runoffs 2023: 2:09.564 (Peter Shadowen)GTL qualifying best at Runoffs 2024: 2:30.858 (Peter Shadowen)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
T4GTLSMsolid race · dashed qualifying · slower is lower
96%98%100%102%104%106%32 rule changes between Runoffs 2018 and Runoffs 201932 ▾44 rule changes between Runoffs 2019 and Runoffs 202044 ▾29 rule changes between Runoffs 2020 and Runoffs 202129 ▾33 rule changes between Runoffs 2021 and Runoffs 202233 ▾28 rule changes between Runoffs 2022 and Runoffs 202328 ▾48 rule changes between Runoffs 2023 and Runoffs 202448 ▾36 rule changes between Runoffs 2024 and Runoffs 202536 ▾29 rule changes between Runoffs 2025 and Runoffs 202629 ▾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)GTL race best at Runoffs 2015: 98.2% of T4's (Jim Dentici)GTL race best at Runoffs 2016: 95.5% of T4's (Kyle Disque)GTL race best at Runoffs 2017: 95.8% of T4's (Christopher Bovis)GTL race best at Runoffs 2018: 96.0% of T4's (Troy Ermish)GTL race best at Runoffs 2019: 97.6% of T4's (Bill Ball)GTL race best at Runoffs 2020: 96.0% of T4's (Peter Shadowen)GTL race best at Runoffs 2021: 96.6% of T4's (Scott Twomey)GTL race best at Runoffs 2022: 97.1% of T4's (Michael Lewis)GTL race best at Runoffs 2023: 99.5% of T4's (Graham Fuller)GTL race best at Runoffs 2024: 97.8% of T4's (Chris Bovis)GTL qualifying best at Runoffs 2015: 96.7% of T4's (Jim Dentici)GTL qualifying best at Runoffs 2016: 96.5% of T4's (Wilson Wright)GTL qualifying best at Runoffs 2017: 94.7% of T4's (Christopher Bovis)GTL qualifying best at Runoffs 2018: 96.0% of T4's (Troy Ermish)GTL qualifying best at Runoffs 2019: 96.8% of T4's (Peter Shadowen)GTL qualifying best at Runoffs 2020: 96.5% of T4's (Chris Bovis)GTL qualifying best at Runoffs 2021: 97.7% of T4's (Christopher Bovis)GTL qualifying best at Runoffs 2022: 98.6% of T4's (Peter Shadowen)GTL qualifying best at Runoffs 2023: 99.3% of T4's (Peter Shadowen)GTL qualifying best at Runoffs 2024: 97.7% of T4's (Peter Shadowen)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)Off the chart: 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
T4GTLSMsolid 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
EventT4GTLSM
Qual best Race best Trap 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%)2:42.173Brett 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%
29 rule changes (T4: 26, GTL: 1, SM: 2)5 cars added · 5 suspension & brakes · 5 weight · 3 induction · 2 removed · 2 tyres & wheels · 1 wording · 6 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
  • GTL Remove GT3U from GCR as it is now in STU #39862removed
  • 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
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%)2:43.111Bobby 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, GTL: 3, SM: 4)7 weight · 5 cars added · 5 tyres & wheels · 3 engine · 2 aero · 2 suspension & brakes · 1 induction · 3 wording · 8 othershowhide
  • 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
  • T4 Ford Mustang V6 (05-14) #37516other
  • T4 Request to Classify Club Spec in Appropriate Touring Classes #37523cars added
  • GTL Correct language regarding OEM Areo Devices #37137aero
  • 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
  • GTL G16E-GTS Fuel Injection Spec Line Change #36588engine
  • GTL GTL Alternate Weight and Choke Option for L16 engine #36653weight
  • 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%)2:30.858Peter Shadowen · fastest of 14 · top 5 within 4.4s-1.085s (-0.71%)2:30.844Chris Bovis · fastest of 13 · top 5 within 3.7s-0.757s (-0.50%)133.3Peter Shadowen+1.8 mph (+1.4%)-3.364squal -3.572s97.8%qual 97.7%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%
48 rule changes (T4: 28, GTL: 16, SM: 4)12 weight · 7 cars added · 7 engine · 6 suspension & brakes · 5 induction · 3 aero · 1 removed · 1 wording · 6 othershowhide
  • GTL Request to Include Toyota GR86 in GTL #36324cars added
  • GTL Inclusion of Modified Spec Miata for GTL competition #36325cars added
  • GTL Include Mazda MX5 RF 2017- in GTL #36428cars added
  • SM SMX Camera Rule Correction #36496wording
  • SM AIM ECU Protocol #36556engine
  • SM OE versus OEM Definitons #36608other
  • SM Shifter Bushing #36611suspension & brakes
  • T4 T4 Camaro V6 weight reduction #36232weight
  • T4 BOP adjustment for ND MX5s #36345weight -50 lbs
  • GTL Add GTL to GT3 choke option line. #36236induction
  • 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
  • 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
  • GTL Request for Spec Line 1010 Reconsideration #35009weight +300 lbs
  • GTL Allow 34 mm chokes for the Datsun 510 #35661induction +50 lbs
  • 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
  • GTL Rear Blade Spoiler Clarification #35261aero
  • GTL GT Direct Injection allowance and rules #35437engine
  • GTL GT2/3 remove Direction Injection not allowed in Spec line notes #35439engine
  • 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
  • GTL Rotary Engine 12A Rotor Housings #35131engine
  • GTL Request to Include Toyota GR86 in GTL #35198cars added
  • GTL Errors and Omissions, GTL engines & Cars #35226engine
  • 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
  • GTL Small Engines in GT Lite #34842engine
  • GTL Request to Classify Honda Fit body in GTL #35020cars added
  • GTL Errors in GTCS Headings and Use of the Terms Category and ClassChange existing GTL and GTA Rules #34453weight
  • GTL Weight for Nissan Sentra/200SX A 1400's #34918weight -50 lbs
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%)2:09.564Peter Shadowen · fastest of 11 · top 5 within 4.9s+1.775s (+1.39%)2:11.277Graham Fuller · fastest of 10 · top 5 within 2.4s-9.903s (-7.01%)142.7Peter Shadowen+6.7 mph (+4.9%)-0.685squal -0.950s99.5%qual 99.3%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%
28 rule changes (T4: 20, GTL: 7, SM: 1)9 weight · 4 suspension & brakes · 3 cars added · 3 engine · 2 induction · 1 tyres & wheels · 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
  • T4 05-06 Mini Wheel Weight #34112weight
  • T4 06-09 VW Rabbit #34153induction
  • T4 96-01 Audi a4 2.8 Spring Rate #34217suspension & brakes
  • GTL Please classify Fields Cardinal V8 #33784cars added
  • T4 Request to Classify 2004-2008 Acura TSX in T4 #33590cars added
  • T4 T4 Mustang Brakes/Swaybar #34036suspension & brakes
  • T4 BMW 320I intercooler #33762other
  • GTL Toyota 4Y Engine Classification Request #33562engine
  • T4 2019-2021 Mazda MX5 ND2 #32027cars added
  • T4 Mustang OEM Grill Request #33333other
  • T4 Mazda OEM LSD was letter 32655 typo #33666wording
  • GTL Toyota 4A-F and 4A-FE 1.6L DOHC 16V Engine Request #33415engine
  • 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
  • GTL Fiat HP Limited Prep X1/9 Weight in GTL #33297weight
  • GTL GT2 (TA2)/GTA Part Number Update #33315induction
  • GTL Request to add Ford Festiva to GTL #33335weight
  • T4 T4 mustang #32789weight -25 lbs
  • T4 Mazda OEM LSD was letter 32655 #32933weight -25 lbs
  • GTL Engine Request #33064engine
  • 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%)2:07.789Peter Shadowen · fastest of 14 · top 5 within 2.2s+0.792s (+0.62%)2:21.180Michael Lewis · fastest of 13 · top 5 within 2.1s+13.343s (+10.44%)136.0Peter Shadowen+4.9 mph (+3.7%)-4.263squal -1.788s97.1%qual 98.6%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, GTL: 3, SM: 1)10 suspension & brakes · 5 tyres & wheels · 4 cars added · 4 weight · 2 engine · 1 induction · 1 removed · 2 wording · 4 othershowhide
  • GTL Tail lights on all GT category race cars. #32799suspension & brakes
  • T4 04-09 Mazda3 Balance Shaft Delete Kit #32795other
  • 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
  • GTL Request to Classify Ginetta G40 in GTL #31599cars added
  • 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
  • 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
  • GTL Request car classification #31032cars 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 Schefer1:51.819Christopher Bovis · fastest of 22 · top 5 within 1.8s+1.488s (+1.35%)1:51.952Scott Twomey · fastest of 19 · top 5 within 1.7s-0.116s (-0.10%)129.5Brian Linn-3.977squal -2.578s96.6%qual 97.7%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%
29 rule changes (T4: 20, GTL: 8, SM: 1)5 weight · 4 tyres & wheels · 3 cars added · 3 induction · 2 suspension & brakes · 1 engine · 3 wording · 8 othershowhide
  • GTL Request to Update GTA Obsolete Part Numbers #30615wording
  • GTL Request clarification for the Honda B18a,bVS B18c #30482weight
  • GTL Request to Allow Hood Bulge on Nissan B13 Sentra #30504other
  • GTL Request BMW E21 Classing #30582tyres & wheels
  • T4 Wrong Part Number on 320i Spec Line #30645wording
  • 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
  • GTL Request for Help for Mazda 12A #29754weight +50 lbs
  • T4 E & O T4 Mustang Wheels #30245tyres & wheels
  • GTL Request LP HP Fiat X1/9 & Bertone 1500 to GTL #30058cars added
  • 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
  • GTL Please Add GTL Nissan 1.8L Engine MRA8DE #29805engine
  • GTL Increase 13b SIR size #29867induction
  • 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
  • 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 Ho2:31.943Chris Bovis · fastest of 14 · top 5 within 6.3s2:31.601Peter Shadowen · fastest of 14 · top 5 within 7.2s131.4Peter Shadowen-6.280squal -5.460s96.0%qual 96.5%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%
44 rule changes (T4: 25, GTL: 17, SM: 2)8 aero · 6 cars added · 6 weight · 5 suspension & brakes · 4 induction · 2 engine · 2 tyres & wheels · 4 wording · 7 othershowhide
  • SM Radiator E&O Clarifications #29294engine
  • GTL GT Category Wording #29193induction
  • GTL Request to change the Mazda 13b restrictor size #28518induction +175 lbs
  • SM Modifications to prevent failures of Rear Brake Caliper Pin #28953suspension & brakes
  • T4 Scion FRS Solo Spec Coupe Gear Ratio #29021other
  • GTL Request to classify 1999-2007 Toyota MR2 Spyder body #28870cars added
  • GTL TA2 Gurney flap wicker clarification #28874aero
  • GTL STO Gurney flap wicker clarification #28883aero
  • GTL GT Gurney flap wicker clarification #28909aero
  • GTL Mazda 13b Restrictor Size Follow up to Letter 28518 #29015induction
  • 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
  • GTL Stall Test #28709induction
  • T4 Request to Classify 2004 Mercedes Benz 320 CLK #27663cars added
  • GTL GTL Wing Rule #28754aero
  • T4 Request to change allowed header part # for T4 06-15 Miata #28223wording
  • T4 Z3M Roadster Weight #28437weight
  • GTL Wing Mounting Upright Size #27641aero
  • GTL Wing Mounting Upright Size #27641aero
  • GTL GTL wing end plates addition #28243aero
  • GTL Clarification to letter #27406 #28309weight -50 lbs
  • 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
  • GTL Windshield Clips #27323other
  • 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
  • GTL Request Factory Five Daytona coupe classification #26308cars added
  • GTL Request to Classify the MK1 two door Jetta #27648cars added
  • 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
  • GTL 88-91 Honda CRX Spec Line Correction #27233weight
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 Boileau2:06.997Peter Shadowen · fastest of 19 · top 5 within 4.0s2:07.837Bill Ball · fastest of 18 · top 5 within 4.2s131.1Peter Shadowen-3.122squal -4.260s97.6%qual 96.8%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%
32 rule changes (T4: 15, GTL: 13, SM: 4)9 weight · 6 cars added · 4 engine · 4 suspension & brakes · 3 tyres & wheels · 2 induction · 3 wording · 1 othershowhide
  • GTL Fun Cup Beetle #27334weight
  • T4 Request spare tire/wheel clarification #27012tyres & wheels
  • T4 Research E&O Mazda MX5 #27112weight
  • GTL GTL #26960weight
  • GTL Request CRZ wheelbase change #26896tyres & wheels
  • T4 MR2 Spyder Year Correction #26936wording
  • T4 Request to allow piggy back ECU on 2000 Mazda Protégé #26085engine
  • T4 Request helper spring as optional #26678suspension & brakes
  • GTL Request to Classify VW Fun Cup Beetle #25986cars added
  • GTL Request GTX Fuel injection for previous GT-1 tube frame cars #26141engine
  • GTL Request to Classify Ligier JS2 R #26535cars added
  • GTL Request for GTL Mazda 13B SIR Increase with Penalty #26572engine
  • GTL Request Ride Height Clarification #26600suspension & brakes
  • T4 Request to classify 2000 - 2001 BMW 323 #25096cars added
  • GTL Request Mazda 12a Rotary SIR Increase #26081induction
  • GTL Request to Classify Mustang 2 Body in GTL #26222cars 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
  • GTL Request for GTL Mini Adjustments #25754weight
  • GTL BMC thru Rover Group remove long inactive mini #25771weight
  • GTL GTX Homologation table update #26034cars added
  • 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 Murray1:47.885Troy Ermish · fastest of 20 · top 5 within 4.5s1:49.458Troy Ermish · fastest of 19 · top 5 within 3.6s109.3Charles Leonard-4.572squal -4.454s96.0%qual 96.0%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 1.1s1:50.331Christopher Bovis · fastest of 26 · top 5 within 1.5s1:52.068Christopher Bovis · fastest of 20 · top 5 within 1.0s-4.855squal -6.235s95.8%qual 94.7%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 0.8s1:35.377Wilson Wright · fastest of 28 · top 5 within 1.2s1:35.912Kyle Disque · fastest of 28 · top 5 within 1.1s-4.485squal -3.436s95.5%qual 96.5%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 1.6s2:11.387Jim Dentici · fastest of 10 · top 5 within 2.2s2:13.564Jim Dentici · fastest of 9 · top 5 within 2.0s-2.430squal -4.499s98.2%qual 96.7%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.