BoP Lab / Buttonwillow Raceway Park

SM vs P pace at Buttonwillow Raceway Park

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

Lap times% of SM

SMPsolid race · dashed qualifying · slower is lower

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

	Event	SM			P
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs SM	% of SM
	Cal Club 2026 CALCL262026-02-21	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%)	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%)	-25.199squal -22.676s	79.4%qual 81.3%
9 rule changes (SM: 3, P: 6)1 cars added · 1 engine · 1 induction · 1 suspension & brakes · 5 wording · Prototype carbon-carbon and carbon-ceramic brake rotors now permitted instead of prohibited. · P class 13B rotary engine restrictor changes to 40mm SIR fuel injection or 41.5mm venturi carburetor. · Prototype class adds Radical SR3 spec line to Table 1 effective 9/1/25. · Prototype P2 cars may now run P2 spec or modified Prototype spec in Prototype class; clarified language and added Radical Cup series table. · Prototype Engine Table A 2-cycle restrictor reduces from 40mm to 38mm venturi size. · SMX drivers must submit data acquisition files on time or face suspension and $250 fine. · SMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fine; level 2 and 4 may carry $500 fine. · Class P adds clarification notes on restrictor requirements, throttle bodies, Mazda 12A engine spec, and P2 auto-based engine rules. · SM cars limited to one set of Hoosier SM 7.5 P205/50/ZR17 per Super Tour event weekend for dry sessions.showhide 2026-01-01 P Request to Continue to Allow Carbon Brakes #39476suspension & brakessuspension & brakesPrototype carbon-carbon and carbon-ceramic brake rotors now permitted instead of prohibited. 2025-09-01 P 13B Rotary Engine Rules Change Request #38856engineunclearP class 13B rotary engine restrictor changes to 40mm SIR fuel injection or 41.5mm venturi carburetor. 2025-09-01 P Add Radical Cup series Radical SR3 spec line to Table 1 #38916cars addedcars addedPrototype class adds Radical SR3 spec line to Table 1 effective 9/1/25. 2025-09-01 P Clarify spec line cars language #38943wordingwordingPrototype P2 cars may now run P2 spec or modified Prototype spec in Prototype class; clarified language and added Radical Cup series table. 2025-08-01 P RM 25-05 - Prototype Engine Table A, 2 Cycle Restrictor Change #38929inductionslowerPrototype Engine Table A 2-cycle restrictor reduces from 40mm to 38mm venturi size. 2025-06-01 SM SMX Data Submission - Penalties #38248wordingwordingSMX drivers must submit data acquisition files on time or face suspension and $250 fine. 2025-06-01 SM Committee) SMX Penaly Clarification updated language #38337wordingwordingSMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fine; level 2 and 4 may carry $500 fine. 2025-05-01 P Add missing punctuation marks #38150wordingwordingClass P adds clarification notes on restrictor requirements, throttle bodies, Mazda 12A engine spec, and P2 auto-based engine rules. 2025-05-01 SM Clarify Tire Marking Regs #38005wordingwordingSM cars limited to one set of Hoosier SM 7.5 P205/50/ZR17 per Super Tour event weekend for dry sessions.
	Cal Club 2025 CALCL252025-02-22	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	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	-27.678squal -27.959s	77.2%qual 76.9%
7 rule changes (SM: 5, P: 2)7 wording · Prototype Staudacher and unrestricted engine notes corrected for minimum weight wording. · Prototype class renamed from P1 to P, affecting designation throughout rules with no performance changes. · SMX allows OE instrument cluster relocation for aftermarket dash mounting, with wiring re-routed only; alternate gauges now permitted. · SMX Spec MX-5 camera requirement wording changed; non-functioning recorder now grounds for penalty or disqualification. · SMX Spec MX-5 must run latest AIM Data Logger Spec MX-5 ECU Protocol; wording clarification for technical compliance. · SMX Mazda Miata OE versus OEM definitions clarified in GCR Section 9.1.7.1. · SM and SMX shifter bushing rules clarified: alternate bushing at shift lever bottom now allowed.showhide 2025-02-01 P Correct text in engine table notes #37606wordingwordingPrototype Staudacher and unrestricted engine notes corrected for minimum weight wording. 2025-02-01 P Update Prototype class designation #37653wordingwordingPrototype class renamed from P1 to P, affecting designation throughout rules with no performance changes. 2024-12-01 SM E&O SMX Regs 9.1.7.1.D.5.u-.w #37070wordingwordingSMX allows OE instrument cluster relocation for aftermarket dash mounting, with wiring re-routed only; alternate gauges now permitted. 2024-09-01 SM SMX Camera Rule Correction #36496wordingwordingSMX Spec MX-5 camera requirement wording changed; non-functioning recorder now grounds for penalty or disqualification. 2024-09-01 SM Committee) AIM ECU Protocol #36556wordingwordingSMX Spec MX-5 must run latest AIM Data Logger Spec MX-5 ECU Protocol; wording clarification for technical compliance. 2024-09-01 SM Committee) OE versus OEM Definitons #36608wordingwordingSMX Mazda Miata OE versus OEM definitions clarified in GCR Section 9.1.7.1. 2024-09-01 SM Committee) Shifter Bushing #36611wordingwordingSM and SMX shifter bushing rules clarified: alternate bushing at shift lever bottom now allowed.
	Cal Club 2023 CALCL232023-02-24
9 earlier rule changes on record, in force before Cal Club 2023 (from 2019)1 suspension & brakes · 1 weight · 7 wording · SM Mazda MX-5 Miata 01-05 weight increases to 2450 lbs, or 2465 with alternate bore. · SM Majors must run authorized Penske shock and mount; Regional competitors' requirement eligibility clarified. · SM adds procedures for testing obsolete part replacements and BOP updates in sanctioned events with CRB approval. · SM aftermarket radiators must mount in original location, maintain core plane, require no body modifications, block openings, keep one OEM fan in stock location; 1990-1997 cars may install upper radiator seal NA75-50-OK7A. · SM rear brake calipers may use single bracket under upper retaining bolt to prevent pin failure. · SM fuel pump and filter must be Mazda or OEM Equivalent part. · SM 1999-2000 model year cars may use replacement Mazda ECU and injector harnesses, unmodified. · SM electrical rules reorganized and clarified; alternator external regulation now prohibited except via OEM ECU/kill switch. · SM removes tire tread protrusion beyond fender opening requirement from GCR 9.1.7.C.5.showhide 2023-01-01 SM BOP for NB1 and NB2 #32309weightslowerSM Mazda MX-5 Miata 01-05 weight increases to 2450 lbs, or 2465 with alternate bore. 2022-04-01 SM Update GCR Section 9.1.7.3.A.1. #32217wordingwordingSM Majors must run authorized Penske shock and mount; Regional competitors' requirement eligibility clarified. 2021-04-01 SM Updates - Obsolete Parts & BOP Parts #30438wordingwordingSM adds procedures for testing obsolete part replacements and BOP updates in sanctioned events with CRB approval. 2020-10-01 SM Radiator E&O Clarifications #29294wordingwordingSM aftermarket radiators must mount in original location, maintain core plane, require no body modifications, block openings, keep one OEM fan in stock location; 1990-1997 cars may install upper radiator seal NA75-50-OK7A. 2020-08-01 SM Modifications to prevent failures of Rear Brake Caliper Pin #28953suspension & brakessuspension & brakesSM rear brake calipers may use single bracket under upper retaining bolt to prevent pin failure. 2019-03-01 SM Request to allow aftermarket fuel filters. #26370wordingwordingSM fuel pump and filter must be Mazda or OEM Equivalent part. 2019-02-01 SM Request 99-00 replacement Wire harnesses #25602wordingwordingSM 1999-2000 model year cars may use replacement Mazda ECU and injector harnesses, unmodified. 2019-02-01 SM Organize and Clarify 9.1.7.C.1.o. #25913wordingwordingSM electrical rules reorganized and clarified; alternator external regulation now prohibited except via OEM ECU/kill switch. 2019-02-01 SM Strike Tire Tread Language #26123wordingwordingSM removes tire tread protrusion beyond fender opening requirement from GCR 9.1.7.C.5.

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