BoP Lab / Buttonwillow Raceway Park

P vs SM pace at Buttonwillow Raceway Park

Quickest here: P 1:32.872 Jim Devenport, Cal Club 2025 qualifying · SM 2:00.831 William Wallis, Cal Club 2025 qualifying

Lap times% of P

PSMsolid race · dashed qualifying · slower is lower

PSMsolid race · dashed qualifying · each class's best lap as a share of P's at the same event (the reference class, changeable above); 100% is level, higher is quicker

	Event	P			SM
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs P	% of P
	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%)	2:01.392Ryan Busk · fastest of 18 · top 5 within 0.8s+0.561s (+0.46%)	2:02.486William Rasmussen · fastest of 18 · top 5 within 1.3s+0.836s (+0.69%)	127.3Sam Rezai+23.4 mph (+22.6%)	+25.199squal +22.676s	125.9%qual 123.0%
9 rule changes (P: 6, SM: 3)2 induction · 2 weight · 1 suspension & brakes · 1 tyres & wheels · 1 wording · 2 othershowhide 2026-01-01 P Request to Continue to Allow Carbon Brakes #39476suspension & brakes 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 2025-06-01 SM SMX Data Submission - Penalties #38248other 2025-06-01 SM Committee) SMX Penaly Clarification updated language #38337wording 2025-05-01 P Add missing punctuation marks #38150weight 2025-05-01 SM Clarify Tire Marking Regs #38005tyres & wheels
	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	2:00.831William Wallis · fastest of 16 · top 5 within 0.9s	2:01.650Nick Leverone · fastest of 16 · top 5 within 0.3s	103.9Evan Jacobs	+27.678squal +27.959s	129.5%qual 130.1%
7 rule changes (P: 2, SM: 5)2 engine · 1 suspension & brakes · 1 tyres & wheels · 1 wording · 2 othershowhide 2025-02-01 P Correct text in engine table notes #37606engine 2025-02-01 P Update Prototype class designation #37653tyres & wheels 2024-12-01 SM E&O SMX Regs 9.1.7.1.D.5.u-.w #37070other 2024-09-01 SM SMX Camera Rule Correction #36496wording 2024-09-01 SM Committee) AIM ECU Protocol #36556engine 2024-09-01 SM Committee) OE versus OEM Definitons #36608other 2024-09-01 SM Committee) Shifter Bushing #36611suspension & brakes
	Cal Club 2023 CALCL232023-02-24
9 earlier rule changes on record, in force before Cal Club 2023 (from 2019)2 engine · 2 suspension & brakes · 2 weight · 1 tyres & wheels · 1 wording · 1 othershowhide 2023-01-01 SM BOP for NB1 and NB2 #32309weight 2022-04-01 SM Update GCR Section 9.1.7.3.A.1. #32217suspension & brakes 2021-04-01 SM Updates - Obsolete Parts & BOP Parts #30438other 2020-10-01 SM Radiator E&O Clarifications #29294engine 2020-08-01 SM Modifications to prevent failures of Rear Brake Caliper Pin #28953suspension & brakes 2019-03-01 SM Request to allow aftermarket fuel filters. #26370wording 2019-02-01 SM Request 99-00 replacement Wire harnesses #25602engine 2019-02-01 SM Organize and Clarify 9.1.7.C.1.o. #25913weight 2019-02-01 SM Strike Tire Tread Language #26123tyres & wheels

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 P" is the class's best as a share of P'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 P'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.