BoP Lab / Buttonwillow Raceway Park

F500 vs SRF vs STL pace at Buttonwillow Raceway Park

Quickest here: STL 1:54.845 Gavin Wardle, Cal Club 2026 race

F500SRFSTLsolid race · dashed qualifying · slower is lower

	Event	F500			SRF				STL
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs F500	Qual best	Race best	Trap	vs F500
	Cal Club 2026 CALCL262026-02-21								1:57.526Jared Korth · fastest of 10 · top 5 within 1.2s+2.563s (+2.23%)	1:54.845Gavin Wardle · fastest of 11 · top 5 within 4.7s-0.837s (-0.72%)	136.6Bryce Johnson+26.2 mph (+23.7%)
6 rule changes (SRF: 3, STL: 3)3 weight · 3 othershowhide 2026-01-01 STL Weight adjustment for STL #39579weight 2025-10-01 SRF Add HD Oil Cooler #38979other 2025-08-01 STL Lotus Weight Reduction #38772weight -50 lbs 2025-05-01 STL E&O: SMX Allowance in STL #37945weight 2025-04-01 SRF Driver Safety & Comfort #37966other 2025-04-01 SRF Update SADEV transmission specs #37992other
	Cal Club 2025 CALCL252025-02-22								1:54.963Nick Leverone · fastest of 16 · top 5 within 3.3s	1:55.682Nick Leverone · fastest of 17 · top 5 within 2.6s	110.4Ryan Gutile
77 earlier rule changes on record, in force before Cal Club 2025 (from 2019)14 tyres & wheels · 13 weight · 12 induction · 12 suspension & brakes · 7 engine · 3 aero · 3 cars added · 5 wording · 8 othershowhide 2024-12-01 STL Request to Remove Miata Hubs from General category #37138tyres & wheels 2024-10-01 SRF Update SRF3 Air Filter Rule #36681other 2024-10-01 SRF Update SRF Brake Rotor Thickness #36687suspension & brakes 2024-10-01 SRF Hoosier Tire Decal Placement #36739tyres & wheels 2024-09-01 SRF Protest Fee Clarification #36540wording 2024-09-01 SRF Update to Letter 36619 with new Hoosier Contingency Decal Info #36624tyres & wheels 2024-08-01 SRF Update Rain Tire Rule and Hoosier Decal Placement #36436tyres & wheels 2024-02-01 STL ST Electric-Assisted Steering Systems #35066other 2024-02-01 STL BOP Adjustments #35112weight 2024-02-01 STL Mazda 12A #35320induction 2024-01-01 SRF Update SRF Rain / Brake Rule #34706suspension & brakes 2024-01-01 SRF Update SRF Brake Light Rule v1 #34853suspension & brakes 2024-01-01 SRF SRF / SRF3 Rule Updates #35268weight 2024-01-01 STL Alternate Carburetor Request for 79-85 RX7 12a #35181induction 2023-10-01 SRF SRF Radiator Rule Update #34805other 2023-06-01 SRF Hoosier SRF Wet Front Tire Rule Update #34189tyres & wheels 2023-06-01 STL Clarify STL table B - IT spec notes on Tires #34187tyres & wheels 2023-05-01 SRF Update SRF Front W2 Rain Tire Part Number #34118tyres & wheels 2023-03-01 SRF Update SRF Brake Rule #33469suspension & brakes 2023-01-01 STL Spec MX5 in STL #33473tyres & wheels 2022-06-01 SRF SRF Tire Rule Update #32614tyres & wheels 2022-06-01 SRF Brake, seal, and air filter clarifications #32670suspension & brakes 2022-03-01 STL Single TB Weight Modifiers #31449weight 2022-03-01 STL Improved Touring Tires #32063tyres & wheels 2022-01-01 STL Throttling Device Clarification #31323induction 2022-01-01 STL Mazda Renesis Restriction #31467induction 2022-01-01 STL Clarification of 79-85 RX7 Spec line #31621wording 2021-12-01 SRF Three Updates to SRF Rules #31523weight 2021-09-01 STL Request to clean up Spec MX-5 Redundancy #31069other 2021-08-01 SRF SRF Wet Tires #30849tyres & wheels 2021-08-01 SRF SADEV-SRF3 Transmission #30926other 2021-08-01 SRF SRF Update Maintenance, Repairs and Seals #30961engine 2021-06-01 SRF SRF3 Alternator Pulley #30684weight 2021-06-01 STL VW Engine Request #30625engine 2021-05-01 STL Solstice Ride Height #30183suspension & brakes 2021-05-01 STL Request Mazda B5 DOHC #30420cars added 2021-05-01 STL Honda B16A (JDM) Restrictor change #30531induction 2021-04-01 STL ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wording 2021-03-01 SRF Mandatory identification: #30223engine 2021-03-01 STL GM Ecotec engines in STL #30247engine 2021-03-01 STL Super Touring Alternate Miata Hubs #30345tyres & wheels 2021-02-01 STL Brake Component Relocation #29990suspension & brakes 2021-02-01 STL Super Touring Wing Clarification #30111aero 2021-02-01 STL Transmission Options #30118other 2021-01-01 STL Request for FWD and RWD Parity #29728weight 2021-01-01 STL Request to Remove Honda F20C 2% Weight Penalty #29815weight 2021-01-01 STL Request for FWD and RWD Parity #30023induction 2020-12-01 SRF SRF Shocks, Springs and Ride Height. #29688suspension & brakes 2020-12-01 STL Request clarification on wing measurement #29640aero 2020-08-01 STL Minimum Weight Determination #27695weight 2020-08-01 STL ST Gurney flap Wicker clarification #29012aero 2020-07-01 STL Request for Addition to GT3 Approved Turbo List #27576induction 2020-06-01 STL Request to add 2016-2019 GMX-5 Spec line #28604cars added 2020-06-01 STL Request to update PN for MX-5 #28622wording 2020-06-01 STL Correction - Clarification Honda/Acura B18B engine Letter # 26209 #28873engine 2020-05-01 SRF SRF Bump Stop Correction #27019suspension & brakes 2020-05-01 STL STL Honda B18 restrictor changes #28794induction 2020-04-01 STL Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0 #27884engine 2020-04-01 STL Acura/Honda B18C engine chart. Reduce the current 54 mm flat plat #28663induction 2020-04-01 STL Mazda MZR engine chart. Reduce the current 55 mm flat plate to 53 #28664induction 2020-03-01 STL Request to add wheel part numbers #28342tyres & wheels 202-01-01 SRF SRF Rain / Brake Rule - BoD approved as follows #34958suspension & brakes 2019-12-01 SRF SRF Tire Warmer Rule #27622tyres & wheels 2019-12-01 SRF SRF / SRF3 Nose Weight Reduction #27706weight 2019-12-01 SRF SRF / SRF3 Majors & Regional Class Updates #27723other 2019-10-01 STL Request to Classify Spec MX-5 Challenge in STL #27399cars added 2019-07-01 SRF SRF Dash Windscreen Kit #27028other 2019-07-01 STL Request clarification for manifold and throttle in STU #27004induction 2019-05-31 STL Request Restrictor Plate correction #26779induction 2019-05-01 STL Request Ride Height Clarification #26597suspension & brakes 2019-03-01 STL Request to Allow VW 1.8L Engine #25614engine 2019-03-01 STL Request to reduce weight of RX8 with Renesis rotary #25781weight -100 lbs 2019-03-01 STL Request for Open Brake Pads On Mazda MX-5 Cup NC #25821suspension & brakes 2019-03-01 STL Request to clarify B18C1 GSR Honda B motor table #26209weight 2019-03-01 STL Port Matching #26415wording 2019-01-01 STL Request to equalize FPR Reduction on all B-Series Vtec Engines #24746weight 2019-01-01 STL Request E&O for Mazda Miata Spec Line #25955weight

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. 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.