F6 vs FB vs SRF vs GT3 pace at Buttonwillow Raceway Park
Quickest here:F6 1:59.670 Jeff Jorgenson, Super Tour Feb 2024 race · FB 1:38.870 Gary Hickman, Super Tour Apr 2018 race · SRF 1:44.060 Vince Balch, Super Tour Apr 2017 qualifying · GT3 1:40.093 Michael Lewis, Super Tour Apr 2018 race
F6FBSRFGT3solid race · dashed qualifying · slower is lower
F6FBSRFGT3solid race · dashed qualifying · each class's best lap as a share of F6's at the same event (the reference class, changeable above); 100% is level, higher is quicker
Event
F6
FB
SRF
GT3
Qual best
Race best
Trap
Qual best
Race best
Trap
vs F6
% of F6
Qual best
Race best
Trap
vs F6
% of F6
Qual best
Race best
Trap
vs F6
% of F6
Super Tour Feb 2024 CALCL242024-02-23
2:00.926Jeff Jorgenson · only car
1:59.670Jeff Jorgenson · only car
104.7Jeff Jorgenson
1:52.853Michael Lewis · fastest of 5 · top 5 within 12.0s+3.395s (+3.10%)
1:52.971Michael Lewis · fastest of 4 · top 4 within 5.0s+0.994s (+0.89%)
119.8Michael Lewis-2.5 mph (-2.1%)
-6.699squal -8.073s
94.4%qual 93.3%
45 rule changes (SRF: 9, GT3: 36)11 cars added · 9 engine · 5 tyres & wheels · 3 weight · 2 induction · 1 aero · 1 suspension & brakes · 7 wording · 6 other · 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. · GT3 Toyota FA24D 2387cc DOHC engine added, 2195 lbs, direct injection permitted. · GT2 Nissan and GT3 Mazda, Mitsubishi 4G93, Nissan QR25DE/DD, QE25DE/DD now permit Direct Injection per 9.1.2.F.7.5.E. · GT3 Nissan QR25DE/DD spec line edit appears corrupted; text unreadable. · GT3 Mazda RX7 12A, 13B Bridgeport, 13B Peripheral Port: disenfranchised GT2 cars add 75 lbs. · GT3 Mazda BP4W turbocharged engine minimum weight reduced 100 lbs to 1960. · GT3 Mazda 13B peripheral port minimum weight reduced to 2100 lbs. · Toyota GR 86 DR86 2021–2024 added to GT3 as rear-wheel-drive coupe, 101.3 in wheelbase. · GT3 Toyota 3S bore increases to 86.0 mm, stroke decreases to 86.0 mm. · 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. · GT3 Toyota 3S DOHC engine classified at 1998 cc, 1960 lbs minimum weight, unrestricted fuel induction. · GT3 2.0L SIR engines remove 32mm restrictor option and 2195 lbs unrestricted weight allowance for all listed makes. · 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. · GT3-TCR Audi RS3 LMS, Honda Civic Type R, Hyundai i30 N, VW Golf GTi must use 200 tread wear any DOT tires. · GT3 Honda B20 engine classified for use; 1973cc DOHC with 84mm bore, 89mm stroke, aluminum head. · SRF radiator options expanded: Enterprises P/N 480465 with baffle 480464, 480466, or Automotive 1R698 and CU698 allowed if cross-reference equivalent. · GT3 allows 15" American Racer 23.5-10.0-15 bias ply tires without weight penalty. · 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. · GT3 Nissan VG30 engine removed from class. · GT3 normally aspirated cars may now use chokes instead of SIRs, same size as listed SIR, one per carburetor barrel. · GT3 2.0L 4-valve non-turbo engines may run unrestricted at 2060 lbs minimum weight. · GT3 Mazda BP4W Turbocharged OEM engine added, 1839cc, 2060 lbs, with 34mm TIR and IHI RHF5 VJ35 turbo. · GT2 TA2 and GTA throttle body part numbers updated to GM 12570790 or Edelbrock 33869/3870. · GT3 Nissan SR20VET turbo ECU changes from stock only to open, enabling tuning. · GT3 adds 84-87 Honda Civic 3dr FWD, 86.6 in wheelbase, hood bulge allowed. · GT3 turbo maximum engine displacement clarified to 1,401-1,850 cc. · GT1, GT2, GT3, GTL, GTX tail lights may now be original style or custom panel graphic with functioning red LED brake lamps. · GT3 adds Nissan SR20VET Limited Prep-Turbocharged OEM engine, 1998cc, 2060 lbs, Garrett GT2560LS turbo only. · GT3 Fiat 124 Spider model name corrected from Pininfarina to Pininfarina Spider. · GT3 Fiat 124 Spider Pininfarina classified with body style, drive-line, and wheelbase specifications. · 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. · GT3 adds 17x9 wheels with 3% weight penalty, 18" wheels with 5% penalty down from 8%, and 13" brake rotors. · GT3-TCR Audi RS3 SEQ/DSG, Honda Civic, Hyundai i30N, VW Golf GTI SEQ power cut to 90%; weights up 2–54 lbs; VW Golf GTI DSG to 97.5%. · GT3 Ginetta G40 classified with Mazda MZR 1999cc at 2060 lbs or Ford Duratec 2260cc at 2195 lbs, both 32mm SIR, 5-speed only. · GT3 Mazda MZR 1999cc DOHC newly classified with 2195 lbs minimum weight, unrestricted fuel induction. · GT3 Volvo S60 2000-2009 four-door sports coupe, front-wheel drive, 106.9 in wheelbase, newly classified. · GT3 2.0L 4V engines may run unrestricted at 2195 lbs minimum weight. · GT3 wing wording corrected; single element airfoil maximum chord length stays 10.75 inches.showhide
GT3 Rear Blade Spoiler Clarification #35261aeroaeroGT1-GTX rear blade spoiler: angle 50–75°, max 59.0 wide by 5.0 high inches; total area limit removed.
GT3 GT Direct Injection allowance and rules #35437engineadded · engineGT1, GT2, GT3, GTL, GTX Direct Injection now permitted if original equipment.
GT3 Request to Include Toyota FA24D Engine for use in GT3 #35199cars addedaddedGT3 Toyota FA24D 2387cc DOHC engine added, 2195 lbs, direct injection permitted.
GT3 GT2/3 remove Direction Injection not allowed in Spec line notes #35439engineadded · engineGT2 Nissan and GT3 Mazda, Mitsubishi 4G93, Nissan QR25DE/DD, QE25DE/DD now permit Direct Injection per 9.1.2.F.7.5.E.
GT3 Edit GT3 Nissan QR25DE/DD spec line #35442otherunclearGT3 Nissan QR25DE/DD spec line edit appears corrupted; text unreadable.
GT3 Turbo Help #35042weight -100 lbsfaster · weightGT3 Mazda BP4W turbocharged engine minimum weight reduced 100 lbs to 1960.
GT3 Competition Adjustment Request for 13B Peripheral Port #35100weight -100 lbsfaster · weightGT3 Mazda 13B peripheral port minimum weight reduced to 2100 lbs.
GT3 Request to Include Toyota GR 86 in GT3 #35197cars addedaddedToyota GR 86 DR86 2021–2024 added to GT3 as rear-wheel-drive coupe, 101.3 in wheelbase.
GT3 Fastrack Toyota 3S Correction #35258engineunclearGT3 Toyota 3S bore increases to 86.0 mm, stroke decreases to 86.0 mm.
SRF Update SRF Rain / Brake Rule #34706otherotherSRF rain/brake light must be Super Bright LEDs Inc. P/N PT-STRB-R24; secondary filament must connect to rain light switch.
SRF Update SRF Brake Light Rule v1 #34853otherotherSRF 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.
GT3 Toyota Engine Classification Request #35019engineadded · engineGT3 Toyota 3S DOHC engine classified at 1998 cc, 1960 lbs minimum weight, unrestricted fuel induction.
GT3 GT3 2.0L SIR & weight #35171inductionslower · inductionGT3 2.0L SIR engines remove 32mm restrictor option and 2195 lbs unrestricted weight allowance for all listed makes.
GT3 Errors in GTCS Headings and Use of the Terms Category and ClassChange existing GTL and GTA Rules #34453wordingwordingGTL 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.
GT3 GT3 TCR 200 TW tires #34993tyres & wheelstyres & wheelsGT3-TCR Audi RS3 LMS, Honda Civic Type R, Hyundai i30 N, VW Golf GTi must use 200 tread wear any DOT tires.
GT3 Classify Honda B20 engine in GT3 CRX #34781cars addedaddedGT3 Honda B20 engine classified for use; 1973cc DOHC with 84mm bore, 89mm stroke, aluminum head.
SRF SRF Radiator Rule Update #34805otheraddedSRF radiator options expanded: Enterprises P/N 480465 with baffle 480464, 480466, or Automotive 1R698 and CU698 allowed if cross-reference equivalent.
GT3 Addendum to letter 33913, GT3 DOT tires. #34627tyres & wheelsfaster · tyres & wheelsGT3 allows 15" American Racer 23.5-10.0-15 bias ply tires without weight penalty.
SRF Hoosier SRF Wet Front Tire Rule Update #34189tyres & wheelstyres & wheelsSRF wet front tyre changes to Hoosier P/N 46100 P185/60R13 H20 or W2 with 2.5" ground clearance.
GT3 Please classify Fields Cardinal V8 #33784cars addedaddedFields Cardinal V8 added to GT1 with Ford V8 engine, 4.9L, 2100 lbs, fuel injection.
SRF Update SRF Front W2 Rain Tire Part Number #34118tyres & wheelstyres & wheelsSRF front W2 rain tyre Hoosier part number changes from 46100 to 46101 P185/65R13.
SRF Update SRF Brake Rule #33469enginefaster · engineSRF 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.
GT3 Remove Nissan VG30 engine from GT3 #33609engineremoved · engineGT3 Nissan VG30 engine removed from class.
GT3 GT3 Choke option effective 1-01-2023 #33669inductionadded · inductionGT3 normally aspirated cars may now use chokes instead of SIRs, same size as listed SIR, one per carburetor barrel.
GT3 GT3 2.0L choke/weight option #33670otheraddedGT3 2.0L 4-valve non-turbo engines may run unrestricted at 2060 lbs minimum weight.
GT3 Turbocharged Engine Rules #33145cars addedaddedGT3 Mazda BP4W Turbocharged OEM engine added, 1839cc, 2060 lbs, with 34mm TIR and IHI RHF5 VJ35 turbo.
GT3 GT2 (TA2)/GTA Part Number Update #33315wordingwordingGT2 TA2 and GTA throttle body part numbers updated to GM 12570790 or Edelbrock 33869/3870.
GT3 GT3 Nissian SR20VET unrestricted ECU change #33432enginefaster · engineGT3 Nissan SR20VET turbo ECU changes from stock only to open, enabling tuning.
GT3 GT3 Turbo Displacement Clarification #32952wordingwordingGT3 turbo maximum engine displacement clarified to 1,401-1,850 cc.
GT3 Tail lights on all GT category race cars. #32799wordingwordingGT1, GT2, GT3, GTL, GTX tail lights may now be original style or custom panel graphic with functioning red LED brake lamps.
GT3 Correct Model GT3 - Fiat #32776wordingwordingGT3 Fiat 124 Spider model name corrected from Pininfarina to Pininfarina Spider.
GT3 Correct Fiat Spider Years #32149cars addedaddedGT3 Fiat 124 Spider Pininfarina classified with body style, drive-line, and wheelbase specifications.
SRF SRF Tire Rule Update #32614wordingwordingSRF tire rule wording clarified: tires must be run as delivered.
SRF Brake, seal, and air filter clarifications #32670otherfasterSRF brake rotor minimum thickness reduced from 13.25 mm to 12.20 mm; seals and air filter specs clarified.
GT3 wheel size addition #32247tyres & wheelsfaster · tyres & wheelsGT3 adds 17x9 wheels with 3% weight penalty, 18" wheels with 5% penalty down from 8%, and 13" brake rotors.
GT3 GT3 TCR Car Feedback #31677engine +2 lbsslower · engineGT3-TCR Audi RS3 SEQ/DSG, Honda Civic, Hyundai i30N, VW Golf GTI SEQ power cut to 90%; weights up 2–54 lbs; VW Golf GTI DSG to 97.5%.
GT3 Request to Classify Ginetta G40 in GT3 #31598cars addedaddedGT3 Ginetta G40 classified with Mazda MZR 1999cc at 2060 lbs or Ford Duratec 2260cc at 2195 lbs, both 32mm SIR, 5-speed only.
GT3 Volvo S60 in GT3 #31970cars addedaddedGT3 Volvo S60 2000-2009 four-door sports coupe, front-wheel drive, 106.9 in wheelbase, newly classified.
GT3 GT3 2.0L 4V engines now unrestricted. #32190enginefaster · engineGT3 2.0L 4V engines may run unrestricted at 2195 lbs minimum weight.
GT3 TB correction to wing wording #32191wordingwordingGT3 wing wording corrected; single element airfoil maximum chord length stays 10.75 inches.
Super Tour Feb 2022 CALCL222022-02-17
1:49.458Troy Ermish · fastest of 10 · top 5 within 7.1s-1.479s (-1.33%)
1:51.977Collin Jackson · fastest of 10 · top 5 within 5.9s+0.817s (+0.73%)
122.3Troy Ermish-17.0 mph (-12.2%)
29 rule changes (SRF: 8, GT3: 21)10 cars added · 6 induction · 1 engine · 1 tyres & wheels · 1 weight · 8 wording · 2 other · GT3 adds Fiat Spider 2000, years 79-81, RWD, 89.76" wheelbase. · GT3 adds Fiat X-19, years 72-89. · GT3 Fun Cup Beetle Sealed minimum weight drops 210 lbs, to 1850. · GT3 adds TCR cars: Audi RS3 LMS, Honda Civic Type R, Hyundai i30N, Volkswagen Golf GTI at 3100–3200 lbs with 200 tread wear tires. · 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 Ford Cortina GT 1964-1968 added to classified cars list. · GT3 Volkswagen Fun Cup Beetle EVO3 classified, sealed SOHC 1984cc engine, 2060 lbs minimum weight. · 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. · GT3 permits current FP spec line cars to compete while maintaining full FP rule set. · SRF3 alternator pulley specified as P/N G902130 or G902130A, minimum 12oz. · GT3 Mazda MZR 2.0L fuel induction restrictor increases from 31 to 32 mm. · GT3 Mazda Renesis and 13B Bridgeport choke size corrected to 42mm. · SRF and SRF3 mandatory identification revised: removed Ford Performance and Blue Oval decals, added Hoosier logo placement. · GT3 Mazda MZR and MZR/L5-VE fuel induction size increases from 31 to 32. · GT3 Honda Prelude 1992-1997 2dr FWD 104" wheelbase newly classified. · SRF rear springs limited to P/N 280390 only, previous part numbers no longer allowed; ground clearance wording clarified. · GT1/GT2/GT3/GTL/GTX turbocharging and supercharging now permitted if listed on spec line. · GT3 Mazda 12A Peripheral Port added, 2300 cc, 2300 lbs, SIR head, 2 valves per cylinder. · 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. · GT3 4v SIR fuel induction increases from 31 to 32 mm across 20 engine variants. · GT3 and STU add Borg-Warner EFR6258 turbocharger to approved turbo lists. · GT3 Nissan KA24E loses 32mm choke option at 2280 lbs for 2011-2012. · SRF Penske shock P/N 280396 bump stop P/N 280407 becomes mandatory, maximum one per shock, effective 05/01/2020. · GT3 Mazda MZR L5-VE fuel induction changed to 31mm SIR, weight increased to 2195 lbs, direct injection prohibited.showhide
GT3 Request to add Fiat to GT3 CARS #31803cars addedaddedGT3 adds Fiat Spider 2000, years 79-81, RWD, 89.76" wheelbase.
GT3 Request to add Fiat to GT3 CARS #31804cars addedaddedGT3 adds Fiat X-19, years 72-89.
GT3 31032 correction to weight #31525weight -210 lbsfaster · weightGT3 Fun Cup Beetle Sealed minimum weight drops 210 lbs, to 1850.
GT3 Add TCR cars to GT3 #31540cars addedaddedGT3 adds TCR cars: Audi RS3 LMS, Honda Civic Type R, Hyundai i30N, Volkswagen Golf GTI at 3100–3200 lbs with 200 tread wear tires.
SRF Three Updates to SRF Rules #31523otherotherSRF 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 Please approve 1964-1968 Ford Cortina GT for competition in GT# #30941cars addedaddedGT3 Ford Cortina GT 1964-1968 added to classified cars list.
GT3 Request car classification #31032cars addedaddedGT3 Volkswagen Fun Cup Beetle EVO3 classified, sealed SOHC 1984cc engine, 2060 lbs minimum weight.
GT3 Request to Update GTA Obsolete Part Numbers #30615wordingwordingGTA part numbers updated: 0-80541-1 to 0-80541-2 in two locations and 6010 to 6014X in TA2 Appendix.
SRF SADEV-SRF3 Transmission #30926cars addedaddedSRF adds SADEV-SRF3 6-speed sequential transmission option with ratios 3.0–0.92:1 and 3.20 final drive.
SRF SRF Update Maintenance, Repairs and Seals #30961wordingwordingSRF 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.
GT3 Request to Permit FP cars in GT3 #30611cars addedaddedGT3 permits current FP spec line cars to compete while maintaining full FP rule set.
SRF SRF3 Alternator Pulley #30684engineadded · engineSRF3 alternator pulley specified as P/N G902130 or G902130A, minimum 12oz.
GT3 Mazda MZR 2.0L Engine #30455inductionfaster · inductionGT3 Mazda MZR 2.0L fuel induction restrictor increases from 31 to 32 mm.
GT3 Disfranchised GT3 Mazda, correct choke size #30570inductioninductionGT3 Mazda Renesis and 13B Bridgeport choke size corrected to 42mm.
SRF Mandatory identification: #30223wordingwordingSRF and SRF3 mandatory identification revised: removed Ford Performance and Blue Oval decals, added Hoosier logo placement.
GT3 Mazda MZR SIR Sizing #29555inductionfaster · inductionGT3 Mazda MZR and MZR/L5-VE fuel induction size increases from 31 to 32.
SRF SRF Shocks, Springs and Ride Height. #29688otherotherSRF rear springs limited to P/N 280390 only, previous part numbers no longer allowed; ground clearance wording clarified.
GT3 GT Category Wording #29193wordingaddedGT1/GT2/GT3/GTL/GTX turbocharging and supercharging now permitted if listed on spec line.
GT3 Request to add Mazda 12A Peripheral Port to GT3 rule set #28842cars addedaddedGT3 Mazda 12A Peripheral Port added, 2300 cc, 2300 lbs, SIR head, 2 valves per cylinder.
GT3 TA2 Gurney flap wicker clarification #28874wordingwordingTA2 Gurney flap wording clarified: replace 'wicker bill' and 'wicker' with 'Gurney flap' throughout wing specifications.
GT3 STO Gurney flap wicker clarification #28883wordingwordingSTO rear wing rules clarify that wicker is called Gurney flap in two places; no performance change.
GT3 GT Gurney flap wicker clarification #28909wordingwordingGT Gurney flap wording clarified: wickerbill and tab terminology replaced with Gurney flap throughout sections 9.1.2.F.7.b.
GT3 GT3 4v SIR size increase. #28931inductionfaster · inductionGT3 4v SIR fuel induction increases from 31 to 32 mm across 20 engine variants.
GT3 Request for Addition to GT3 Approved Turbo List #27576cars addedaddedGT3 and STU add Borg-Warner EFR6258 turbocharger to approved turbo lists.
GT3 Request Nissan KA24E specifications #28808inductionremoved · inductionGT3 Nissan KA24E loses 32mm choke option at 2280 lbs for 2011-2012.
SRF SRF Bump Stop Correction #27019wordingwordingSRF Penske shock P/N 280396 bump stop P/N 280407 becomes mandatory, maximum one per shock, effective 05/01/2020.
GT3 Error Regarding Mazda Engine Listing #28119induction +245 lbsslower · inductionGT3 Mazda MZR L5-VE fuel induction changed to 31mm SIR, weight increased to 2195 lbs, direct injection prohibited.
Super Tour Feb 2020 ST20FEB212020-02-21
1:50.937Michael Lewis · fastest of 10 · top 5 within 5.7s-0.936s (-0.84%)
1:51.160Michael Lewis · fastest of 11 · top 5 within 3.8s-3.520s (-3.07%)
139.3Taz Harvey+16.7 mph (+13.6%)
16 rule changes (SRF: 5, GT3: 11)5 cars added · 2 engine · 2 induction · 1 aero · 1 tyres & wheels · 1 weight · 2 wording · 2 other · GT1, GT2, GT3, GTL, GTX may use bonded-glass factory windshields without clips or straps if attached per original specifications. · 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. · GT3 Mazda 13B Bridgeport restrictor reduced from 44mm to 42mm. · GT3 Alfa 4C turbocharged 1742cc classified with 33mm restrictor, minimum weight 2325 lbs. · GT3 Mazda MZR/L5-VE gets unrestricted fuel induction, drops to 1950 lbs minimum weight, limited to GT2 prep. · GT3 adds Honda K20C1 turbocharged engine, 1928 cc, 33 mm restrictor, 2350 lbs minimum. · GT3 wing end plates change from 11.00 × 4.00 inch rectangle to maximum 64 square inches. · SRF rain and brake rule supersedes GCR 9.3.32.B.2 effective 1/1/2024 through 12/31/2024. · GT3 Nissan adds SR16VE engine, 1596 cc DOHC, 1690 lbs, unrestricted fuel induction. · 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. · GT3 Mazda 12A Bridgeport gains optional 42mm choke at 2010 lbs minimum weight. · SRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102. · GTX tube frame cars now allowed fuel injection with maximum 90mm throttle body. · GTX adds Ligier JS2 R classification with restrictor and minimum weight.showhide
GT3 Windshield Clips #27323otheraddedGT1, GT2, GT3, GTL, GTX may use bonded-glass factory windshields without clips or straps if attached per original specifications.
GT3 Request Factory Five Daytona coupe classification #26308cars addedaddedGTX 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.
GT3 Request restrictor size change request #26958inductionslower · inductionGT3 Mazda 13B Bridgeport restrictor reduced from 44mm to 42mm.
GT3 GT3 wing end plate #28035otherunclearGT3 wing end plates change from 11.00 × 4.00 inch rectangle to maximum 64 square inches.
SRF SRF Rain / Brake Rule - BoD approved as follows #34958wordingwordingSRF rain and brake rule supersedes GCR 9.3.32.B.2 effective 1/1/2024 through 12/31/2024.
GT3 Request to Add SR16VE to GT-3 Spec Lines #27357cars addedaddedGT3 Nissan adds SR16VE engine, 1596 cc DOHC, 1690 lbs, unrestricted fuel induction.
SRF SRF Tire Warmer Rule #27622tyres & wheelstyres & wheelsSRF adds tire warmer prohibition and specifies Hoosier dry and wet tire part numbers.
SRF SRF / SRF3 Nose Weight Reduction #27706weightfaster · weightSRF front nose weight minimum reduced from 35 to 32 lbs.
SRF SRF / SRF3 Majors & Regional Class Updates #27723wordingwordingSRF2 becomes Regional Only; SRF3 nomenclature changed from GEN3 to Ford 1.6L conversion; SRF and SRF3 no longer compete together for points.
GT3 Requesting Increase in Choke Diameter for Mazda 12A Bridgeport #27043inductionadded · inductionGT3 Mazda 12A Bridgeport gains optional 42mm choke at 2010 lbs minimum weight.
SRF SRF Dash Windscreen Kit #27028aeroadded · aeroSRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102.
GT3 Request GTX Fuel injection for previous GT-1 tube frame cars #26141engineadded · engineGTX tube frame cars now allowed fuel injection with maximum 90mm throttle body.
GT3 Request to Classify Ligier JS2 R #26535cars addedaddedGTX adds Ligier JS2 R classification with restrictor and minimum weight.
Super Tour Apr 2019 ST19APR262019-04-26
1:51.873Michael Lewis · fastest of 11 · top 5 within 6.2s+0.532s (+0.48%)
1:54.680Michael Lewis · fastest of 10 · top 5 within 2.9s+14.587s (+14.57%)
122.7Michael Lewis
5 rule changes (GT3: 5)1 cars added · 1 weight · 1 wording · 2 other · GT3 Mazda 13B and Renesis engines completely respecified with new induction types and weights ranging 2080–2350 lbs. · GT1 and GT2/3/Lite remove ride height ground clearance rules; cars may now touch ground when tires deflate. · GT3 13B Street Port removed; 13B Peripheral Port weight raised to 2400 lbs; 13B Bridge Port weight raised to 2400 lbs; Renesis Street Port removed; Renesis Peripheral Port weight raised to 2450 lbs; Renesis Bridge Port weight raised to 245… · GT3 adds Mitsubishi 4G69 SOHC engine, 2378 cc, 2195 lbs, 31mm SIR. · 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.showhide
GT3 26076 revised Spec line chart #26528otherunclearGT3 Mazda 13B and Renesis engines completely respecified with new induction types and weights ranging 2080–2350 lbs.
GT3 Request Ride Height Clarification #26600wordingfasterGT1 and GT2/3/Lite remove ride height ground clearance rules; cars may now touch ground when tires deflate.
GT3 Request clarification on bridge porting for rotary #26076weightslower · weightGT3 13B Street Port removed; 13B Peripheral Port weight raised to 2400 lbs; 13B Bridge Port weight raised to 2400 lbs; Renesis Street Port removed; Renesis Peripheral Port weight raised to 2450 lbs; Renesis Bridge Port weight raised to 245…
GT3 GTX Homologation table update #26034otherunclearGTX 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.
Super Tour Apr 2018 BUTTRA182018-04-27
1:39.142Gary Hickman · fastest of 2-3.130s (-3.06%)
1:38.870Gary Hickman · fastest of 2-1.241s (-1.24%)
1:51.341Michael Lewis · fastest of 7 · top 5 within 6.9s+1.772s (+1.62%)
1:40.093Michael Lewis · fastest of 6 · top 5 within 16.8s-12.227s (-10.89%)
No rule changes on record between these events
Super Tour Apr 2017 BUTTRA172017-04-28
1:42.272John LaBrie · fastest of 2
1:40.111Gary Hickman · fastest of 2
1:44.060Vince Balch · fastest of 8 · top 5 within 18.6s
2:01.122Mike Miserendino · fastest of 7 · top 5 within 1.8s
1:49.569Collin Jackson · fastest of 5 · top 5 within 13.8s
1:52.320Collin Jackson · fastest of 5 · top 5 within 12.1s
About this data
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 F6" is the class's best as a share of F6'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 F6'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.