BoP Lab / Buttonwillow Raceway Park

FB vs F6 vs SRF vs P pace at Buttonwillow Raceway Park

Quickest here: P 1:32.872 Jim Devenport, Cal Club 2025 qualifying

FBF6SRFPsolid race · dashed qualifying · slower is lower

	Event	FB			F6				SRF				P
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs FB	Qual best	Race best	Trap	vs FB	Qual best	Race best	Trap	vs FB
	Cal Club 2026 CALCL262026-02-21												1:38.716Kevin Mitz · fastest of 3 · top 3 within 3.1s+5.844s (+6.29%)	1:37.287John Manfroy · fastest of 3 · top 3 within 3.5s+3.315s (+3.53%)	160.4John Manfroy+18.7 mph (+13.2%)
9 rule changes (SRF: 3, P: 6)2 induction · 2 weight · 1 suspension & brakes · 4 othershowhide 2026-01-01 P Request to Continue to Allow Carbon Brakes #39476suspension & brakes 2025-10-01 SRF Add HD Oil Cooler #38979other 2025-09-01 P 13B Rotary Engine Rules Change Request #38856induction 2025-09-01 P Add Radical Cup series Radical SR3 spec line to Table 1 #38916other 2025-09-01 P Clarify spec line cars language #38943weight 2025-08-01 P RM 25-05 - Prototype Engine Table A, 2 Cycle Restrictor Change #38929induction 2025-05-01 P Add missing punctuation marks #38150weight 2025-04-01 SRF Driver Safety & Comfort #37966other 2025-04-01 SRF Update SADEV transmission specs #37992other
	Cal Club 2025 CALCL252025-02-22												1:32.872Jim Devenport · fastest of 3 · top 3 within 8.1s	1:33.972Jim Devenport · fastest of 3 · top 3 within 7.7s	141.7Jim Devenport
30 earlier rule changes on record, in force before Cal Club 2025 (from 2019)9 tyres & wheels · 8 suspension & brakes · 4 weight · 3 engine · 1 wording · 5 othershowhide 2025-02-01 P Correct text in engine table notes #37606engine 2025-02-01 P Update Prototype class designation #37653tyres & 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 2024-01-01 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 2023-10-01 SRF SRF Radiator Rule Update #34805other 2023-06-01 SRF Hoosier SRF Wet Front Tire Rule Update #34189tyres & 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 2022-06-01 SRF SRF Tire Rule Update #32614tyres & wheels 2022-06-01 SRF Brake, seal, and air filter clarifications #32670suspension & brakes 2021-12-01 SRF Three Updates to SRF Rules #31523weight 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 2021-03-01 SRF Mandatory identification: #30223engine 2020-12-01 SRF SRF Shocks, Springs and Ride Height. #29688suspension & brakes 2020-05-01 SRF SRF Bump Stop Correction #27019suspension & brakes 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 2019-07-01 SRF SRF Dash Windscreen Kit #27028other

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.