FC vs GT1 vs STL pace at Indianapolis Motor Speedway
Quickest here:FC 1:36.336 Austin McCusker, Runoffs 2017 qualifying · GT1 1:35.279 Michael Lewis, Runoffs 2021 qualifying · STL 1:51.665 Danny Steyn, Runoffs 2021 qualifying
FCGT1STLsolid race · dashed qualifying · slower is lower
FCGT1STLsolid race · dashed qualifying · each class's best lap as a share of FC's at the same event (the reference class, changeable above); 100% is level, higher is quicker
Event
FC
GT1
STL
Qual best
Race best
Trap
Qual best
Race best
Trap
vs FC
% of FC
Qual best
Race best
Trap
vs FC
% of FC
Runoffs 2021 ROFF212021-09-25
1:36.787Trent Walko · fastest of 31 · top 5 within 1.7s+0.451s (+0.47%)
1:36.980Simon Sikes · fastest of 31 · top 5 within 2.0s+0.090s (+0.09%)
141.6Tim Minor
1:35.279Michael Lewis · fastest of 20 · top 5 within 0.6s-0.729s (-0.76%)
1:53.220David Pintaric · fastest of 14 · top 5 within 3.8s+17.033s (+17.71%)
180.2Tom Smith
+16.240squal -1.508s
116.7%qual 98.4%
1:51.665Danny Steyn · fastest of 42 · top 5 within 1.7s-0.982s (-0.87%)
2:02.711Joe Moser · fastest of 37 · top 5 within 3.2s+10.122s (+8.99%)
131.8Max Gee
+25.731squal +14.878s
126.5%qual 115.4%
63 rule changes (FC: 7, GT1: 19, STL: 37)11 cars added · 10 induction · 8 weight · 3 aero · 3 engine · 28 wording · STL Spec MX-5 removes redundant specification line; no performance change. · GTA part numbers updated: 0-80541-1 to 0-80541-2 in two sections and 6010 to 6014X in TA2 Appendix. · STL Volkswagen 2.0L TFSI 1984cc classified with turbocharger removal required, meeting all other STL specs. · STL Pontiac Solstice/Saturn Sky allowed 4" ride height. · STL Mazda B5 DOHC added to classification with standard STL regulations. · STL Honda B16A JDM restrictor reduced from 54mm to 53mm. · ST oil coolers and filters now explicitly allowed to be added or substituted; wording clarifies existing permissions. · FC Pinto engine loses 10 lbs to 1190; Pinto aluminum head loses 10 lbs to 1190; Zetec loses 10 lbs to 1210. · STL GM Ecotec engines now permit any combination within the family, must use 55mm flat plate restrictor. · STL/STU 90-05 Mazda Miata gains approval for Mazda Motorsports Development alternate front wheel hubs. · ST cars may relocate ABS actuation hardware and wiring anywhere in engine compartment. · STL rear wing trailing edge, including end plates and gurney flap, maximum rearward mounting clarified to center of rearmost bodywork. · STL allows OEM gear sets from same manufacturer transmissions with input shaft modifications for fitment. · STL RWD strut suspension weight penalty cut to 0.5%, other RWD cut to 2.5%. · STL Honda F20C loses 2% weight penalty, minimum weight reduced by approximately 35 lbs. · STL Honda B16/B17/B18C1 restrictor tightened to 53mm; B18C variants and Mazda MZR to 52mm. · ST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch. · FC: Pectel T2 and Performance PE-3 ECU maps clarified; SCCA Club or 2013 Pro map required. · GT1, GT2, GT3, GTL, GTX now permit turbocharging/supercharging if listed on spec line. · FC Zetec engine minimum weight increases 20 lbs to 1220 lbs. · GT1 adds Trans Am spec engines: Chevrolet R07, Ford FR9, Dodge R7, each with 50 lbs. weight penalty. · STL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis adjustments. · STL and STU rear wing rules clarify that wicker is a Gurney flap; no performance change. · TA2 Gurney flap wording clarified: terminology standardized to 'Gurney flap', height limits and thickness specifications remain 0.50 inch / 0.625 inch or 0.375 inch / 0.0625 inch depending on configuration. · STO rear wing wording clarified: 'wicker' changed to 'Gurney flap' in maximum chord and mounting height rules. · GT1 Gurney flap wicker clarification: terminology standardized from lips/tabs/wicker to flaps throughout specifications. · GT classes clarify Gurney flap wording, replacing wickerbill/tab terminology with flap; specifications unchanged. · GT3 and STU add Borg-Warner EFR6258 to approved turbocharger list. · STL adds 2016-2019 Mazda MX-5 Global Cup at 2000cc, 2450-2550 lbs minimum weight. · STL Mazda MX-5 Club Model 06-15 allows Mazda header part number 0000-06-5407-NC. · STL Honda/Acura B18 non-C gets 54mm restrictor; B18C variants drop B18C1, get 53mm restrictor. · STL Honda B18 restrictor reduced from 54mm to 53mm flat plate; B18C1 added with 54mm restrictor. · STU GM Ecotech LNF now allowed with turbo removed or with LE5 head and intake manifold, meeting STL specs. · STL Mazda MZR restrictor reduced from 54 mm to 53 mm. · STL Mazda MZR restrictor reduced from 55 mm to 53 mm. · STL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL. · GT1, GT2, GT3, GTL, GTX may omit windshield clips if factory glass is bonded per original specifications. · GT2/ST Ford 5.0L Coyote 3rd Gen OEM added at 3200 lbs with Boss intake manifold permitted. · Factory Five Type 65 Coupe R with Ford 302/351 or 5.0/5.2L NA added to GTX-MISC at 2600 lbs. · GT1 sequential shifting transmission weight penalty reduced from 75 to 50 lbs. · GT1 non-18-inch-wheel cars now get 18-inch wheels with 50 lb penalty, down from 100 lb. · GT1 Spec Lines allows 5 Star NASCAR Camaro 2018+ body for General Motors Corporation. · FC Zetec connecting rods now allow Eagle #CRS5483F3D in addition to original Ford. · FC adds Mahle #930169439 piston as alternate option to existing Ford, Sealed Power, and United Engine choices. · Mazda Spec MX-5 Challenge classified in STL with 2000cc displacement and 2500 lbs minimum weight. · GT1 Porsche 944/968 classified: 2981cc twin turbo, 2585 lbs minimum weight. · GT1 allows Trans Am rear wing, 12" chord, 72" span, 1/2" wicker, 100 sq in endplates, no weight penalty. · STU alternate intake manifolds now allowed case-by-case instead of prohibited. · STL Acura/Honda B18 except C engine restrictor increases from 53mm to 54mm flat plate. · FC Wiseco piston and Crower connecting rod part numbers updated; minimum weight 976 grams. · GTX tube frame cars gain fuel injection with 90mm maximum throttle body size. · Ligier JS2 R classified in GTX, no performance parameters specified in filing. · STL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld. · GT1 and GT2/GT3/LITE ride height requirements removed from GCR sections 9.1.2.D.5.a.1 and 9.1.2.F.7.b. · STL adds VW 1.8L R4 20VT 1781cc, 1 minimum weight, turbo removed permitted. · STL Mazda Renesis minimum weight reduced from 2800 to 2700 lbs. · STL Mazda MX-5 Cup brake pad compound changed to open. · STL adds Acura/Honda B18C1 GSR with 54mm flat plate restrictor and port matching limited to 1 inch. · STL Mazda 12 and 13B now permit port matching; previous ban removed. · FC Wiseco piston and Crower connecting rod assembly minimum weight increases from 555 to 976 grams. · GTX FIA GT3: Audi R8 40mm restrictor 2900 lbs, BMW Z4 70mm 2800 lbs, Ferrari 488 35mm restrictor 3025 lbs classified. · STL B18C Type R variants get 54mm flat plate restrictor; B17 also gets 54mm restrictor. · STL Mazda Miata removes maximum displacement limit and adjusts minimum weight.showhide
STL Request to clean up Spec MX-5 Redundancy #31069wordingneutralSTL Spec MX-5 removes redundant specification line; no performance change.
GT1 Request to Update GTA Obsolete Part Numbers #30615wordingneutralGTA part numbers updated: 0-80541-1 to 0-80541-2 in two sections and 6010 to 6014X in TA2 Appendix.
STL VW Engine Request #30625engineslowerSTL Volkswagen 2.0L TFSI 1984cc classified with turbocharger removal required, meeting all other STL specs.
STL Request Mazda B5 DOHC #30420cars addedneutralSTL Mazda B5 DOHC added to classification with standard STL regulations.
STL Honda B16A (JDM) Restrictor change #30531inductionslowerSTL Honda B16A JDM restrictor reduced from 54mm to 53mm.
STL ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wordingneutralST oil coolers and filters now explicitly allowed to be added or substituted; wording clarifies existing permissions.
FC Request for FC Weight Change #30171weightfasterFC Pinto engine loses 10 lbs to 1190; Pinto aluminum head loses 10 lbs to 1190; Zetec loses 10 lbs to 1210.
STL GM Ecotec engines in STL #30247wordingneutralSTL GM Ecotec engines now permit any combination within the family, must use 55mm flat plate restrictor.
STL Super Touring Alternate Miata Hubs #30345wordingneutralSTL/STU 90-05 Mazda Miata gains approval for Mazda Motorsports Development alternate front wheel hubs.
STL Brake Component Relocation #29990wordingneutralST cars may relocate ABS actuation hardware and wiring anywhere in engine compartment.
STL Super Touring Wing Clarification #30111aeroneutralSTL rear wing trailing edge, including end plates and gurney flap, maximum rearward mounting clarified to center of rearmost bodywork.
STL Transmission Options #30118wordingneutralSTL allows OEM gear sets from same manufacturer transmissions with input shaft modifications for fitment.
STL Request for FWD and RWD Parity #29728weightfasterSTL RWD strut suspension weight penalty cut to 0.5%, other RWD cut to 2.5%.
STL Request to Remove Honda F20C 2% Weight Penalty #29815weightfasterSTL Honda F20C loses 2% weight penalty, minimum weight reduced by approximately 35 lbs.
STL Request for FWD and RWD Parity #30023inductionslowerSTL Honda B16/B17/B18C1 restrictor tightened to 53mm; B18C variants and Mazda MZR to 52mm.
STL Request clarification on wing measurement #29640aeroneutralST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch.
FC Urgent: SCCA PE3 map unsuitable #29475wordingneutralFC: Pectel T2 and Performance PE-3 ECU maps clarified; SCCA Club or 2013 Pro map required.
GT1 GT Category Wording #29193wordingunclearGT1, GT2, GT3, GTL, GTX now permit turbocharging/supercharging if listed on spec line.
FC Request for weight adjustments to equalize FC competition. #28888weightslowerFC Zetec engine minimum weight increases 20 lbs to 1220 lbs.
GT1 Request to Allow New Trans Am Legal Engines in GT1 #29002engineslowerGT1 adds Trans Am spec engines: Chevrolet R07, Ford FR9, Dodge R7, each with 50 lbs. weight penalty.
STL Minimum Weight Determination #27695wordingneutralSTL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis adjustments.
STL ST Gurney flap Wicker clarification #29012wordingneutralSTL and STU rear wing rules clarify that wicker is a Gurney flap; no performance change.
GT1 TA2 Gurney flap wicker clarification #28874wordingneutralTA2 Gurney flap wording clarified: terminology standardized to 'Gurney flap', height limits and thickness specifications remain 0.50 inch / 0.625 inch or 0.375 inch / 0.0625 inch depending on configuration.
GT1 STO Gurney flap wicker clarification #28883wordingneutralSTO rear wing wording clarified: 'wicker' changed to 'Gurney flap' in maximum chord and mounting height rules.
GT1 GT1 Gurney flap wicker clarification #28886wordingneutralGT1 Gurney flap wicker clarification: terminology standardized from lips/tabs/wicker to flaps throughout specifications.
STL Request for Addition to GT3 Approved Turbo List #27576wordingneutralGT3 and STU add Borg-Warner EFR6258 to approved turbocharger list.
STL Request to add 2016-2019 GMX-5 Spec line #28604cars addedneutralSTL adds 2016-2019 Mazda MX-5 Global Cup at 2000cc, 2450-2550 lbs minimum weight.
STL Request to update PN for MX-5 #28622wordingunclearSTL Mazda MX-5 Club Model 06-15 allows Mazda header part number 0000-06-5407-NC.
STL Correction - Clarification Honda/Acura B18B engine Letter # 26209 #28873inductionunclearSTL Honda/Acura B18 non-C gets 54mm restrictor; B18C variants drop B18C1, get 53mm restrictor.
STL STL Honda B18 restrictor changes #28794inductionfasterSTL Honda B18 restrictor reduced from 54mm to 53mm flat plate; B18C1 added with 54mm restrictor.
STL Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0 #27884engineslowerSTU GM Ecotech LNF now allowed with turbo removed or with LE5 head and intake manifold, meeting STL specs.
STL Acura/Honda B18C engine chart. Reduce the current 54 mm flat plat #28663inductionslowerSTL Mazda MZR restrictor reduced from 54 mm to 53 mm.
STL Mazda MZR engine chart. Reduce the current 55 mm flat plate to 53 #28664inductionslowerSTL Mazda MZR restrictor reduced from 55 mm to 53 mm.
STL Request to add wheel part numbers #28342wordingneutralSTL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL.
GT1 Windshield Clips #27323wordingneutralGT1, GT2, GT3, GTL, GTX may omit windshield clips if factory glass is bonded per original specifications.
GT1 Request to classify the Ford Coyote 3rd Gen OEM #27146cars addedneutralGT2/ST Ford 5.0L Coyote 3rd Gen OEM added at 3200 lbs with Boss intake manifold permitted.
GT1 Request Factory Five Daytona coupe classification #26308cars addedneutralFactory Five Type 65 Coupe R with Ford 302/351 or 5.0/5.2L NA added to GTX-MISC at 2600 lbs.
GT1 Request to Adjust Transmission Penalty #27750weightfasterGT1 sequential shifting transmission weight penalty reduced from 75 to 50 lbs.
GT1 Request to Reduce Additional Weight for 18 #27751weightfasterGT1 non-18-inch-wheel cars now get 18-inch wheels with 50 lb penalty, down from 100 lb.
GT1 Request for Five Star Nascar Compliant Bodywork #27756cars addedneutralGT1 Spec Lines allows 5 Star NASCAR Camaro 2018+ body for General Motors Corporation.
FC Request for Better Zetec Connecting Rods #27710wordingneutralFC Zetec connecting rods now allow Eagle #CRS5483F3D in addition to original Ford.
FC Add Alternate Piston #27795wordingneutralFC adds Mahle #930169439 piston as alternate option to existing Ford, Sealed Power, and United Engine choices.
STL Request to Classify Spec MX-5 Challenge in STL #27399cars addedneutralMazda Spec MX-5 Challenge classified in STL with 2000cc displacement and 2500 lbs minimum weight.
GT1 Clarify Trans Am Legal Bodywork and Wing #26953aerofasterGT1 allows Trans Am rear wing, 12" chord, 72" span, 1/2" wicker, 100 sq in endplates, no weight penalty.
STL Request clarification for manifold and throttle in STU #27004inductionfasterSTU alternate intake manifolds now allowed case-by-case instead of prohibited.
STL Request Restrictor Plate correction #26779inductionfasterSTL Acura/Honda B18 except C engine restrictor increases from 53mm to 54mm flat plate.
FC E&O Wiseco piston and Crower connecting rod #26659wordingneutralFC Wiseco piston and Crower connecting rod part numbers updated; minimum weight 976 grams.
GT1 Request GTX Fuel injection for previous GT-1 tube frame cars #26141inductionfasterGTX tube frame cars gain fuel injection with 90mm maximum throttle body size.
GT1 Request to Classify Ligier JS2 R #26535cars addedneutralLigier JS2 R classified in GTX, no performance parameters specified in filing.
STL Request Ride Height Clarification #26597wordingneutralSTL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld.
GT1 Request Ride Height Clarification #26600wordingneutralGT1 and GT2/GT3/LITE ride height requirements removed from GCR sections 9.1.2.D.5.a.1 and 9.1.2.F.7.b.
STL Request to reduce weight of RX8 with Renesis rotary #25781weight -100 lbsfasterSTL Mazda Renesis minimum weight reduced from 2800 to 2700 lbs.
STL Request for Open Brake Pads On Mazda MX-5 Cup NC #25821wordingneutralSTL Mazda MX-5 Cup brake pad compound changed to open.
STL Request to clarify B18C1 GSR Honda B motor table #26209cars addedneutralSTL adds Acura/Honda B18C1 GSR with 54mm flat plate restrictor and port matching limited to 1 inch.
STL Port Matching #26415wordingfasterSTL Mazda 12 and 13B now permit port matching; previous ban removed.
FC Correct Wiseco piston and connecting rod #25809weightslowerFC Wiseco piston and Crower connecting rod assembly minimum weight increases from 555 to 976 grams.
GT1 GTX Homologation table update #26034cars addedneutralGTX FIA GT3: Audi R8 40mm restrictor 2900 lbs, BMW Z4 70mm 2800 lbs, Ferrari 488 35mm restrictor 3025 lbs classified.
STL Request to equalize FPR Reduction on all B-Series Vtec Engines #24746inductionslowerSTL B18C Type R variants get 54mm flat plate restrictor; B17 also gets 54mm restrictor.
STL Request E&O for Mazda Miata Spec Line #25955wordingunclearSTL Mazda Miata removes maximum displacement limit and adjusts minimum weight.
Runoffs 2017 ROFF172017-09-25
1:36.336Austin McCusker · fastest of 14 · top 5 within 2.3s
1:36.890Tim Minor · fastest of 14 · top 5 within 3.8s
1:36.008David Pintaric · fastest of 17 · top 5 within 2.2s
1:36.187Cliff Ebben · fastest of 16 · top 5 within 1.5s
-0.703squal -0.328s
99.3%qual 99.7%
1:52.647Adam Roberts · fastest of 57 · top 5 within 0.8s
1:52.589Eric Kutil · fastest of 50 · top 5 within 1.2s
+15.699squal +16.311s
116.2%qual 116.9%
Best is the class's fastest lap in that event's qualifying or race sessions, with the driver who set it, how many cars set a time that session and how close the top five were; a best from fewer than three cars is greyed. With two or more classes, "vs" is the gap of each class's best to the first class's at the same event. "% of FC" is the class's best as a share of FC's best at the same event (100% is level, less is quicker): weather and track condition move every class together, so this compares across years where the raw times do not. It still breaks when FC's own field changes or one session was wet and another dry. Newest event first. The coloured figure under each value is the change from the previous event that has one (green is quicker, red slower). Whole laps only, so events with different sector layouts still compare. Weather and track condition are not accounted for.