BoP Lab / Buttonwillow Raceway Park
FE vs SRF vs FB vs GT1 pace at Buttonwillow Raceway Park
Quickest here: GT1 1:39.857 Michael McAleenan, Super Tour Feb 2026 qualifying
| Event | FE | SRF | FB | GT1 | ||||||||||||||||
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| Qual best | Race best | Trap | Qual best | Race best | Trap | vs FE | % of FE | Qual best | Race best | Trap | vs FE | % of FE | Qual best | Race best | Trap | vs FE | % of FE | |||
| Super Tour Feb 2026 CALCL262026-02-21 | 1:39.857Michael McAleenan · fastest of 2-4.110s (-3.95%) | 1:41.045Michael McAleenan · fastest of 2-1.260s (-1.23%) | 167.6Michael McAleenan+53.8 mph (+47.3%) | |||||||||||||||||
11 rule changes (FE: 3, SRF: 3, GT1: 5)4 cars added · 2 engine · 1 weight · 3 wording · 1 other · GT1 adds Porsche 992.1 GT3 Cup 2022–2025 with OEM ABS, traction control, RSR bumper, canards, and any exhaust. · FE adds engine modification restrictions, testing requirements, and drivetrain violation penalties with competition suspension. · GT1-ST Acura NSX GT3 EVO 22 minimum weight drops 100 lbs to 3000. · FE and FE2 Enterprise bubble tail part WM138014 now allowed; FE2 must use this configuration only. · Acura NSX GT3 EVO 22 reclassified from GT1 to GT1-ST, 3500cc, 3100 lbs minimum weight. · SRF3 adds HD Oil Cooler P/N G1148500 option alongside standard P/N G480503, no fan permitted. · FE2 minimum weight stays 1270 lbs; intake manifold part number changes to WM301061; ECU to G992012; mandatory spec parts expanded; bubble tail WM138014 now FE only; SADEV transmission no modifications allowed; brake rotor part numbers to W… · GT1 LS Limited Prep engine expanded to include LS2, LS3, LS6 alongside LS1; compression ratio capped at 11:1. · 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. · Acura NSX GT3 EVO 22 classified in GT1 with 3500cc twin turbo crossflow V-6, 3100 lbs, 7500 rpm max.show
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| Super Tour Feb 2025 CALCL252025-02-22 | 1:43.967Michael Lewis · only car | 1:42.305Michael Lewis · only car | 113.8Michael Lewis | |||||||||||||||||
97 rule changes (FE: 26, SRF: 28, GT1: 43)16 cars added · 9 tyres & wheels · 8 weight · 6 aero · 6 engine · 5 suspension & brakes · 1 induction · 35 wording · 11 other · GT1 LS1 Limited Prep engine added, 2600 lbs with driver, 383 cubic inches maximum, hydraulic roller cam, 750 cfm carb. · TA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof height limit. · GT1-ST restrictor specifications removed for 13 cars; new values not provided. · FE must use SCCA Part # WM803010 Brake Line to Control Arm covers if used, as delivered, fastened with zip ties or tape only. · GT1-ST Lamborghini Huracán GT3 Evo and GT3 both move to unrestricted intake, replacing 39mm and 52mm restrictors. · GT1 Mazda 26B engine approved; minimum weight set to 2850 lbs. · 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. · FE and SRF protest fee rules redirected to GCR section 8.3.1.D for fees and procedure. · FE Hoosier contingency decal requirement reduced from five decals in specific locations to three decals on sides and front. · FE and SRF protest fee rules redirected to GCR section 8.3.1.D for fees and procedure. · SRF Hoosier contingency decal requirement reduced from four decals in specific locations to three decals with simplified placement. · FE requires five Hoosier decals: one small on nose or front shock cover, one 12" on each front wing plate, one 12" on each lower floor panel before rear wheels. · 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. · GT2-ST Acura NSX minimum weight rises to 3000 lbs, restrictor increases to 45mm TIR. · GT1 Camaro 1993-2002 model years specified in GCR 9.1.2.E.1.b.3. · 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. · FE rain light now must meet FIA Standard 8874-2019, Technical List No. 76, effective 1/1/2024. · FE allows racer's tape for crash repair, panel security, and heat exchanger opening control; seam taping banned. · GT1-ST adds Lamborghini Huracan GT3 EVO(1) 2018- at 3000 lbs, X39mm restrictor, and Huracan GT3 2019- at 3100 lbs, 52mm restrictor. · GT1 Trick Flow Specialties Ultra 18 Degree GM Cylinder Head Part #TFS-3181T001-CO1 allowed. · 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 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. · SRF radiator options expanded: Enterprises P/N 480465 with baffle 480464, 480466, or Automotive 1R698 and CU698 allowed if cross-reference equivalent. · 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. · FE SADEV transmission rule removes note that all ratios under review and could be updated prior to sealing. · GT1 Mercedes AMG GT3 16-19 notes clarify FIA GT3 homologation compliance. · 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. · GT1 sequential transmission weight penalty reduced from 50 lbs to 25 lbs. · GT1-ST Porsche 992 GT3 Cup added with 3997cc displacement, 2950 lb minimum weight, no restrictor. · GT2 TA2 and GTA throttle body part numbers updated to GM 12570790 or Edelbrock 33869/3870. · GT1 Trans Am bodywork weight penalty reduced from 100 lbs to 75 lbs. · GT1 Chevrolet RO7, Ford FR9, and Dodge R7 weight penalties cut from 50 lbs to 25 lbs each. · FE drivers may now adjust brake bias manually during the race. · FE front and rear wing specifications clarified: adjustment ranges, shimming, Gurney flap sizes, mounting hardware, and measurement references refined. · FE engine heat shield and insulation between block and exhaust now permitted to protect fuel cell, filter, rail, lines. · GT1, GT2, GT3, GTL, GTX tail lights may now be original style or custom panel graphic with functioning red LED brake lamps. · GT1 allows current Trans Am bodywork with 100 lb weight penalty. · FE tires must be run as delivered in sets of 4. · FE master cylinders clarified: Girling front .700" piston WM802005, rear .750" piston WM802006. · 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. · GT1 Mercedes Benz AMG GT3 added, 3050 lbs, 6208cc V8, 40mm restrictors, FIA GT3 homologation. · GT1 wheel width limits change: 12in front/13in rear standard, 18in wheels get 13in front/14in rear maximum. · GT1 allows 17-inch wheels; 18-inch wheels now permitted with 50 lb penalty; 18-inch tyres use 13-inch front, 14-inch rear width. · 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. · 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. · FE removes qualifying tire marking requirements and rain tire set rules; renumbers tire warmer prohibition. · FE radiator screens may not protrude more than ¼ inch in front of the outside vertical plane of the sidepods. · FE radiator screens now allowed, maximum ¼ inch from sidepod front vertical plane. · SRF3 alternator pulley specified as P/N G902130 or G902130A, minimum 12oz. · SRF and SRF3 mandatory identification revised: removed Ford Performance and Blue Oval decals, added Hoosier logo placement. · FE front springs change to 800 lbs Hypercoil WM203013 Silver; rear to 900 lbs Hypercoil WM203014 Silver. · SRF rear springs limited to P/N 280390 only, previous part numbers no longer allowed; ground clearance wording clarified. · FE Gurney flaps clarified: front wing secondary only at 0.500" ±0.030", rear wing at 0.250" ±0.030". · GT1/GT2/GT3/GTL/GTX turbocharging and supercharging now permitted if listed on spec line. · GT1 adds Trans Am spec engines: Chevrolet R07, Ford FR9, Dodge R7, each at base weight plus 50 lbs. · 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. · GT1 Gurney flap and wickerbill terminology clarified: 'lips' and 'tabs' and 'wicker' standardized to 'flaps' throughout section D and E. · GT Gurney flap wording clarified: wickerbill and tab terminology replaced with Gurney flap throughout sections 9.1.2.F.7.b. · FE Gurney flap wicker bill clarified: permitted on front wing secondary elements only, not main plane. · FE2 and FE spring part numbers WM203013 front and WM203014 rear required date moved to November 1, 2020. · SRF Penske shock P/N 280396 bump stop P/N 280407 becomes mandatory, maximum one per shock, effective 05/01/2020. · GT1, GT2, GT3, GTL, GTX may use bonded-glass factory windshields without clips or straps if attached per original specifications. · FE2 Mazda 2.0L MZR engine now permitted in all SCCA events at 1250 lbs minimum; FE 2.3L becomes Regional Only through 2019 Runoffs. · GT2/ST Ford Coyote 5.0L third generation OEM gains Boss intake manifold option at 3200 lbs minimum. · 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. · GT1 sequential shifting transmissions weight penalty reduced from 75 lbs to 50 lbs. · GT1 cars not specified for 18 inch wheels now have 50 pound penalty, down from 100. · GT1 adds 5 Star NASCAR Camaro 2018 and later body as allowed bodywork option. · SRF rain and brake rule supersedes GCR 9.3.32.B.2 effective 1/1/2024 through 12/31/2024. · FE minimum weight rises to 1270 lbs; FE2 minimum weight rises to 1270 lbs; new spring options added; tire warmers prohibited. · 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. · FE Hoosier wet rear tire width increases from 7.5 to 8.0 inches, part number 44196 W3. · GT1 Porsche 944/968 added: 2981cc twin-turbo four, 2585 lbs minimum weight. · FE removes American Racer tires, mandates Hoosier dry tires 22.0 X 8.0-13 and 22.0 X 10.0-13, wet tires 22.0 X 7.5-13 and 22.0 X 9.0-13. · GT1 allows Trans Am rear wing, 72" span, 12" chord, 1/2" wicker, 100 sq in endplates, no weight penalty; front undertray allowed with 50 lb penalty. · SRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102. · FE anti-roll bar links may be removed one per end for safety, but bars must stay connected. · FE and FE2 Enterprise bubble tail P/N WM138014 newly allowed for both classes. · GTX tube frame cars now allowed fuel injection with maximum 90mm throttle body. · GTX adds Ligier JS2 R classification with restrictor and minimum weight.show
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| Super Tour Apr 2019 ST19APR262019-04-26 | ||||||||||||||||||||
3 earlier rule changes on record, in force before Super Tour Apr 2019 (from 2019)1 tyres & wheels · 1 wording · 1 other · GT1 and GT2/3/Lite remove ride height ground clearance rules; cars may now touch ground when tires deflate. · FE Hoosier rain tyre part numbers updated: front 44195 W3, rear 44217 W3. · 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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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 FE" is the class's best as a share of FE'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 FE'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.