BoP Lab / Classes / GTL
GTL vs F5 vs SRF3 pace at every track
Lap times across years say as much about the weather as the class. % of GTL is each class's best lap as a share of GTL'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.
Quickest here: GTL 1:35.377 Wilson Wright, Runoffs 2016 qualifying · F5 1:28.528 Calvin Stewart, Runoffs 2016 qualifying · SRF3 1:34.363 John Black, Runoffs 2016 qualifying
| Event | GTL | F5 | SRF3 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Qual best | Race best | Trap | Qual best | Race best | Trap | vs GTL | % of GTL | Qual best | Race best | Trap | vs GTL | % of GTL | |||
| Road America Runoffs 20262026-09-28 | 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%) | ||||||||||||
3 rule changes (GTL: 1, SRF3: 2)2 engine · 1 cars added · GT3U class removed from GCR; GT3U cars now compete in STU. · SRF3 spark plugs limited to NGK LTR7IX-11 P/N G301041 only; washers and sealing rings prohibited. · SRF3 adds HD Oil Cooler P/N G1148500 option alongside standard P/N G480503, no fan permitted.show
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| Road America Runoffs 20252025-09-29 | 2:28.226Bobby 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%) | ||||||||||||
6 rule changes (GTL: 3, SRF3: 3)2 engine · 2 wording · 2 other · SRF3 adds oil cooler options P/N G480503 and P/N G1148500; brake rule restructured to list Hawk Blue pads, Wilwood rotor, caliper kit, master cylinder options. · SRF drivers with disabilities may modify seat and controls for safety and comfort with SCCA approval, noted in logbook, for that driver only. · SRF SADEV-SRF3 6-speed sequential transmission: effective date clarified to 1 April 2025 onward. · TA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof height limit. · GTL Toyota G16E-GTS removes direct injection prohibition, allowing direct injection engines. · GTL L16 limited prep gains 32mm choke option at 1910 lbs, compression capped 12.0:1, valve lift .450 max.show
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| Road America Runoffs 20242024-10-01 | 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%) | 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%) | -2.715squal -3.085s | 98.2%qual 98.0% | |||||||
26 rule changes (GTL: 16, SRF3: 10)5 cars added · 4 weight · 3 engine · 2 suspension & brakes · 1 aero · 1 induction · 1 tyres & wheels · 5 wording · 4 other · SRF3 air filter rule removes K&N RC-9160 option, specifies Weems P/N WM301020 only. · SRF Wilwood vented rotor minimum thickness increases to 13.25mm, 0.522 inches. · SRF3 Hoosier decal placement changed from four logos on nose and tail to three logos on sides and center front. · GTL adds Toyota GR86 2021–2023, 2dr RWD, 101.3 in wheelbase. · GTL adds Spec Miata 1990–2005 with legal Spec Miata engine and intake system. · GTL adds Mazda MX5 RF 2017- model with 91.0 in wheelbase. · SRF Hoosier contingency decal requirement reduced from four decals in specific locations to three decals with simplified placement. · SRF wet tyres: front P185/60R13 H20 or W2 and rear P205/60R13 H20 or W2 removed; front P185/65R13 W2 and rear P205/60R13 W2 now required. Hoosier decal placement specified. · GTL added to GT3 choke option line in GCR 9.1.2.E.13.n. · SRF3 alternator pulley minimum weight drops from 12 to 11 oz, adds P/N G902131 six-row option. · GT2-ST Acura NSX minimum weight rises to 3000 lbs, restrictor increases to 45mm TIR. · GTL Datsun 510 Limited Prep fuel induction increased to 34 mm chokes, minimum weight rises to 2000 lbs. · GT1-GTX rear blade spoiler: angle 50–75°, max 59.0 wide by 5.0 high inches; total area limit removed. · GT1, GT2, GT3, GTL, GTX Direct Injection now permitted if original equipment. · GT2 Nissan and GT3 Mazda, Mitsubishi 4G93, Nissan QR25DE/DD, QE25DE/DD now permit Direct Injection per 9.1.2.F.7.5.E. · GTL 12A rotary engines may machine and use 13B housing to O.E. 12A spec across all port types. · GTL Toyota DR86 2021–2024 added to class. · GTL BMW Mini model years changed to 2002-2013. · SRF rain/brake light must be Super Bright LEDs Inc. P/N PT-STRB-R24; secondary filament must connect to rain light switch. · SRF brake light must be Super Bright LEDs Inc. P/N PT-STRB-R24, with SCCA Enterprises P/N 180427A pigtail and strobing rain light kit. · SRF adds mandatory front brake ducts 12–36 inches, throttle pedal heel-toe extension, braided stainless flex lines, camber limit 5.0 degrees, radiator opening height 3½ ± ½ inches, rear shift cable clamp P/N WM302007A. · GTL small unrestricted engines under 1399cc lose 38–79 lbs across Alfa, AMC, Triumph, Mini, Sprite, Fiat, Ford, Honda, Mazda, Nissan, Subaru, Toyota, Volkswagen. · GTL Honda Fit 2009-13 2-door FWD added with 99.0 in wheelbase, alternate 94.0 and 97.0 in. · GTL spec lines moved contiguous with GT2 and GT3; GTA category and specs renumbered behind GTL; P2 engine tables reorganised with restrictor and weight specifications clarified. · GTL Nissan Sentra/200SX A 1400 minimum weight reduced to 1800 lbs. · SRF radiator options expanded: Enterprises P/N 480465 with baffle 480464, 480466, or Automotive 1R698 and CU698 allowed if cross-reference equivalent.show
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| Virginia International Raceway Runoffs 20232023-09-23 | 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%) | 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%) | -6.366squal -5.722s | 95.2%qual 95.6% | |||||||
11 rule changes (GTL: 7, SRF3: 4)4 cars added · 2 engine · 2 tyres & wheels · 1 weight · 2 wording · SRF wet front tyre changes to Hoosier P/N 46100 P185/60R13 H20 or W2 with 2.5" ground clearance. · Fields Cardinal V8 added to GT1 with Ford V8 engine, 4.9L, 2100 lbs, fuel injection. · SRF front W2 rain tyre Hoosier part number changes from 46100 to 46101 P185/65R13. · SRF removes 1985 Renault Alliance solid front rotor option; restrictor sizes decrease 1mm for newer Kawasaki and multi-brand engines; minimum weights increase to 1100 lbs. · SRF3 alternate dash panel P/N 180100 or 180101 moved from optional to required bodywork section. · GTL 3K, 4K, 5K Toyota engines may now use 4Y block only. · GT2 and GTL add Toyota 4A-F and 4A-FE 1.6L DOHC 16V engines as permitted options. · GTL Fiat X1/9 1500 Limited Prep minimum weight increases to 2000 lbs from 1835 lbs. · GT2 TA2 and GTA throttle body part numbers updated to GM 12570790 or Edelbrock 33869/3870. · GTL adds Ford Festiva 1988-1993 FWD hatchback with Mazda B3 1324cc engine. · GTL adds Toyota G16E-GTS 1618cc DOHC 3-cyl engine, 1945 lbs, SIR, no turbo or direct injection.show
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| Virginia International Raceway Runoffs 20222022-09-24 | 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%) | 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%) | +0.682squal -10.100s | 100.5%qual 92.1% | 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%) | +0.886squal -4.073s | 100.6%qual 96.8% | ||
12 rule changes (GTL: 3, F5: 6, SRF3: 3)2 cars added · 1 engine · 5 wording · 4 other · F500 Rotax 493 and 593 intake boots: removed Moto Tassinari V3124-873B-2 from 493/593 non-HO allowance, added Moto Tassinari V3120-794A-2 option for non-HO. · GT1, GT2, GT3, GTL, GTX tail lights may now be original style or custom panel graphic with functioning red LED brake lamps. · F500 Rotax engines now permit Ingi Tech Sparker ignition DCP-CDI-P2 as alternate ECU. · F500 clarifies stepped diameter exhaust headers prohibited except at cylinder head flange area. · F500 Rotax 593 intake boot options clarified; oil injection pump removal now permitted. · SRF tire rule wording clarified: tires must be run as delivered. · SRF brake rotor minimum thickness reduced from 13.25 mm to 12.20 mm; seals and air filter specs clarified. · F500 Majors and Runoffs cars must install AIM part #X47KPFSOLO2R0 data box mount for Solo or Solo 2. · Ginetta G40 added to GTL with Ford Zetec 1796cc engine, 2050 lbs minimum weight, 22.5mm SIR. · F5 cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs. · SRF wet tyres front P185/65R13 W2 option added; air box clarified as-delivered; SRF3 restrictor plate G301048 mandatory Jan 1 2022; P2 motorcycle engines up to 1005cc with 35mm restrictor, 2009+ stock 1075 lbs, 2008 stock 1025 lbs, modifie… · GT3 Volkswagen Fun Cup Beetle EVO3 classified, sealed SOHC 1984cc engine, 2060 lbs minimum weight.show
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| Indianapolis Motor Speedway Runoffs 20212021-09-25 | 1:51.819Christopher 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 | 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 | -8.812squal -9.200s | 92.1%qual 91.8% | 1:49.520Franklin 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 | -1.857squal -2.299s | 98.3%qual 97.9% | ||
17 rule changes (GTL: 8, F5: 3, SRF3: 6)5 cars added · 2 induction · 1 aero · 1 engine · 1 tyres & wheels · 5 wording · 2 other · F5 clarifies mechanical shifting only; throttle-cut and flat-shifter devices permitted if driver retains full control. · F5 single-seat open-wheel cars: rigid suspension becomes limited suspension in class definition. · GTA part numbers updated: 0-80541-1 to 0-80541-2 in two locations and 6010 to 6014X in TA2 Appendix. · SRF wet tyres add Hoosier W2 option alongside existing H20 from October 4, 2021. · SRF adds SADEV-SRF3 6-speed sequential transmission option with ratios 3.0–0.92:1 and 3.20 final drive. · SRF seal requirements clarified: seals now must be on driveline components in designated locations; unsealed components removed and inspected by CSR or Enterprises rather than engine shipped for testing. · GTL Honda B18 split into B18A/B at 1797 cc 2050 lbs and B18C at 1834 cc 2065 lbs. · GTL Nissan B13 Sentra may have hood bulge maximum 1.5 inches high by 10.0 long by 6.0 wide. · unclear · F500 Rotax 593 HO engine now permitted; 875 lbs minimum weight, MA0242SP1020A or MA0242SP1063A restrictor, specific intake boots and piston required. · SRF3 alternator pulley specified as P/N G902130 or G902130A, minimum 12oz. · GTL Mazda 12A SIR increases to 29mm, minimum weight rises to 2000 lbs, 28mm SIR option with 175 lb penalty removed. · SRF and SRF3 mandatory identification revised: removed Ford Performance and Blue Oval decals, added Hoosier logo placement. · GTL adds FIAT X-1/9 Bertone 1500 SOHC, 1498 cc, 2000 lbs, fuel injection or carburetors permitted. · GTL Nissan MRA8DE 1.8L engine added, 1797 cc, DOHC, 2050 lbs minimum weight. · GTL Mazda 13B SIR increases from 26 mm to 28 mm; 27 mm option with 175 lbs removed. · SRF rear springs limited to P/N 280390 only, previous part numbers no longer allowed; ground clearance wording clarified.show
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| Road America Runoffs 20202020-10-02 | 2:31.943Chris Bovis · fastest of 14 · top 5 within 6.3s | 2:31.601Peter Shadowen · fastest of 14 · top 5 within 7.2s | 131.4Peter Shadowen | 2:20.954Calvin Stewart · fastest of 16 · top 5 within 1.8s | 2:21.391James Weida · fastest of 14 · top 5 within 1.5s | 143.2Aaron Ellis | -10.210squal -10.989s | 93.3%qual 92.8% | 2:29.786TJ Acker · fastest of 59 · top 5 within 0.5s | 2:31.038Justin Hille · fastest of 55 · top 5 within 0.2s | 131.9Charles Russell Turner | -0.563squal -2.157s | 99.6%qual 98.6% | ||
30 rule changes (GTL: 17, F5: 6, SRF3: 7)4 aero · 3 cars added · 2 engine · 2 induction · 2 suspension & brakes · 2 weight · 1 tyres & wheels · 13 wording · 1 other · F500 Suzuki GSXR600 engine years extended from 2003-2013 to 2003-2019. · GT1/GT2/GT3/GTL/GTX turbocharging and supercharging now permitted if listed on spec line. · GTL Mazda 13B restrictor increases from 24mm to 26mm SIR, minimum weight rises to 2125 lbs, alternative 27mm SIR option adds 175 lbs. · F5 request to adjust external jetting device cockpit control denied; no rule change made. · F5 driver adjustable carburettor mixture: refer to separate Fastrack letter #28359 for ruling. · F5 cockpit adjustment request response published in Fastrack letter 28359. · GTL: Toyota MR2 Spyder 1999–2007 newly classified for GTL competition. · TA2 Gurney flap wording clarified: replace 'wicker bill' and 'wicker' with 'Gurney flap' throughout wing specifications. · STO rear wing rules clarify that wicker is called Gurney flap in two places; no performance change. · GT Gurney flap wording clarified: wickerbill and tab terminology replaced with Gurney flap throughout sections 9.1.2.F.7.b. · GTL Mazda 13B restrictor size addressed in response to letter 28518; see that letter for details. · GTL SIR stall test procedure clarified: system tested as raced, competitor must prevent air bypass behind restrictor. · SRF3 shocks no longer require the same brand in all positions; only SCCA P/N 280407 bump stops allowed, one per shock, all must be sealed by Enterprises. · GTL wing mount openings excluded from square inch area limit. · SRF3 bump stop must be SCCA P/N 280407, no modifications, optional, maximum one per shock. · SRF Penske shock P/N 280396 bump stop P/N 280407 becomes mandatory, maximum one per shock, effective 05/01/2020. · GTL wing mounting posts limited to 85 square inches exposed area each, measured flat from side view. · GTL wing mounting posts limited to 85 square inches each, measured flat from side view. · GTL wing endplates maximum area increased to 64 square inches from 8.5 by 3.0 inches rectangle. · GTL Mazda 12A street port minimum weight drops to 1950 lbs. · GT1, GT2, GT3, GTL, GTX may use bonded-glass factory windshields without clips or straps if attached per original specifications. · F500 Honda CBR600RR, Suzuki GSXR600, Yamaha R6 restrictor reduced to 28mm from 29mm. · GTX Misc. adds Factory Five Type 65 Coupe R Ford 302/351 and 5.0/5.2L NA at 2600 lbs, plus Ferrari 458/488 Challenge, Ford FP350S, Chevrolet C6, Lamborghini Super Trofeo. · GTL adds Jetta Mk1 two-door classification effective 2020-01-01. · SRF rain and brake rule supersedes GCR 9.3.32.B.2 effective 1/1/2024 through 12/31/2024. · GTL Honda CRX 84-87 and 88-91 lose permission to use IRS with 2.5% weight penalty. · SRF adds tire warmer prohibition and specifies Hoosier dry and wet tire part numbers. · SRF front nose weight minimum reduced from 35 to 32 lbs. · SRF2 becomes Regional Only; SRF3 nomenclature changed from GEN3 to Ford 1.6L conversion; SRF and SRF3 no longer compete together for points.show
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| Virginia International Raceway Runoffs 20192019-10-05 | 2:06.997Peter Shadowen · fastest of 19 · top 5 within 4.0s | 2:07.837Bill Ball · fastest of 18 · top 5 within 4.2s | 131.1Peter Shadowen | 1:57.361Wiley Mcmahan · fastest of 15 · top 5 within 3.8s | 1:57.572Wiley Mcmahan · fastest of 15 · top 5 within 4.0s | 142.8Eric McRee | -10.265squal -9.636s | 92.0%qual 92.4% | 2:04.624Brian Schofield · fastest of 54 · top 5 within 0.6s | 2:04.755Bobby Sak · fastest of 53 · top 5 within 0.3s | 132.4Bobby Sak | -3.082squal -2.373s | 97.6%qual 98.1% | ||
17 rule changes (GTL: 13, F5: 1, SRF3: 3)4 cars added · 2 aero · 2 engine · 2 weight · 1 induction · 1 removed · 3 wording · 2 other · F500 Honda CBR600RR, Suzuki GSXR600, and Yamaha R6 minimum weights increase to 900 lbs. · GTL Fun Cup Beetle engine weight set to 1850 lbs with Weber DMTL 32/34 induction. · GTL Fun Cup Beetle removes reference to VW engine table; Fun Cup engines only permitted. · GTL Honda CRZ 10-14, CRZ 15-16, and Insight 00-06 gain alternate wheelbase option of 90.6 inches. · SRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102. · SRF3 multi-piece nose assembly approved for use; no other nose modifications allowed. · GTL Fun Cup Beetle added, all model years, 2-door RWD, 94.5 in wheelbase, VW Fun Cup spec chassis. · GTX tube frame cars now allowed fuel injection with maximum 90mm throttle body. · GTX adds Ligier JS2 R classification with restrictor and minimum weight. · GTL Mazda 13B may use 25mm SIR with 175 lbs weight penalty added. · SRF3 brakes now accept Hawk Blue 9012 pads P/N 801993 only; Wilwood vented rotor P/N 800065 minimum 13.25mm as delivered; caliper bushings P/N 1196185 A or B permitted. Shock absorbers: Penske P/N 280396 only, sealed, with SCCA bump rubber… · GT1 and GT2/3/Lite remove ride height ground clearance rules; cars may now touch ground when tires deflate. · GTL Mazda 12A may use 28mm SIR plus 175 lbs. · GTL: Ford Mustang 94-04 body newly classified for GTL racing. · GTL Mini 1275–1399 Iron and Aluminum Crossflow with OE common sump gearbox reduce weight by 125 lbs, up from 50 lbs. · GTL BMC thru Rover Group removes four long inactive Mini engines: 948, 970, 1071, 1098. · GTX FIA GT3: Audi R8 now 40 mm restrictor and 2900 lbs; BMW Z4 now 70 mm restrictor and 2800 lbs; Ferrari 488 now 35 mm restrictor, TIR, and 3025 lbs.show
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| Sonoma Raceway Runoffs 20182018-10-10 | 1:47.885Troy Ermish · fastest of 20 · top 5 within 4.5s | 1:49.458Troy Ermish · fastest of 19 · top 5 within 3.6s | 109.3Charles Leonard | 1:41.807Jeff Jorgenson · fastest of 5 · top 5 within 6.6s | 1:42.491David Lapham · fastest of 5 · top 5 within 9.5s | 113.3David Lapham | -6.967squal -6.078s | 93.6%qual 94.4% | 1:46.117Robeson Clay Russell · fastest of 36 · top 5 within 0.5s | 1:47.053TJ Acker · fastest of 35 · top 5 within 0.2s | 110.2Steve Fogg | -2.405squal -1.768s | 97.8%qual 98.4% | ||
| No rule changes on record between these events | |||||||||||||||
| Indianapolis Motor Speedway Runoffs 20172017-09-25 | 1:50.331Christopher Bovis · fastest of 26 · top 5 within 1.5s | 1:52.068Christopher Bovis · fastest of 20 · top 5 within 1.0s | 1:43.136Wiley Clinton McMahan · fastest of 38 · top 5 within 1.4s | 1:42.860Wiley Clinton McMahan · fastest of 37 · top 5 within 1.6s | -9.208squal -7.195s | 91.8%qual 93.5% | 1:49.824John Black · fastest of 101 · top 5 within 0.5s | 1:49.782Tray Ayres · fastest of 94 · top 5 within 0.4s | -2.286squal -0.507s | 98.0%qual 99.5% | |||||
| No rule changes on record between these events | |||||||||||||||
| Mid-Ohio Sports Car Course Runoffs 20162016-09-19 | 1:35.377Wilson Wright · fastest of 28 · top 5 within 1.2s | 1:35.912Kyle Disque · fastest of 28 · top 5 within 1.1s | 1:28.528Calvin Stewart · fastest of 14 · top 5 within 3.9s | 1:29.853Steven Thompson · fastest of 12 · top 5 within 4.5s | -6.059squal -6.849s | 93.7%qual 92.8% | 1:34.363John Black · fastest of 41 · top 5 within 0.5s | 1:34.947Cliff White · fastest of 39 · top 5 within 0.3s | -0.965squal -1.014s | 99.0%qual 98.9% | |||||
| No rule changes on record between these events | |||||||||||||||
| Daytona International Speedway Runoffs 20152015-09-21 | 2:11.387Jim Dentici · fastest of 10 · top 5 within 2.2s | 2:13.564Jim Dentici · fastest of 9 · top 5 within 2.0s | 2:01.824W. Clint McMahan · fastest of 16 · top 5 within 3.0s | 2:03.298Matthew Strand · fastest of 15 · top 5 within 4.9s | -10.266squal -9.563s | 92.3%qual 92.7% | 2:08.557Kerry Jacobsen · fastest of 29 · top 5 within 1.1s | 2:10.215Chad Galloway · fastest of 29 · top 5 within 0.3s | -3.349squal -2.830s | 97.5%qual 97.8% | |||||
By track
| Track | Events | Typical % of GTL | Best | Latest |
|---|---|---|---|---|
| Road America | 4 | 100.0%2 of 4 with GTL | 100.0%Runoffs 2020 | 100.0%Runoffs 2024 |
| Virginia International Raceway | 3 | 100.0% | 100.0%Runoffs 2019 | 100.0%Runoffs 2023 |
| Indianapolis Motor Speedway | 2 | 100.0% | 100.0%Runoffs 2017 | 100.0%Runoffs 2021 |
| Daytona International Speedway | 1 | 100.0% | 100.0%Runoffs 2015 | 100.0%Runoffs 2015 |
| Mid-Ohio Sports Car Course | 1 | 100.0% | 100.0%Runoffs 2016 | 100.0%Runoffs 2016 |
| Sonoma Raceway | 1 | 100.0% | 100.0%Runoffs 2018 | 100.0%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 GTL's best on the same day: the weather, the track and its configuration cancel out, so one figure compares across tracks and years where lap times cannot. 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.