BoP Lab / Buttonwillow Raceway Park

F5 vs F6 vs FM vs B-Spec pace at Buttonwillow Raceway Park

Quickest here: B-Spec 2:09.353 Trenton Kramer, Super Tour Feb 2026 qualifying

F5F6FMB-Specsolid race · dashed qualifying · slower is lower

	Event	F5			F6				FM				B-Spec
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs F5	Qual best	Race best	Trap	vs F5	Qual best	Race best	Trap	vs F5
	Super Tour Feb 2026 CALCL262026-02-21												2:09.353Trenton Kramer · fastest of 5 · top 5 within 6.1s-1.160s (-0.89%)	2:09.916Trenton Kramer · fastest of 5 · top 5 within 2.7s-0.138s (-0.11%)	121.5Trenton Kramer+23.3 mph (+23.8%)
24 rule changes (B-Spec: 24)7 suspension & brakes · 7 weight · 3 induction · 1 cars added · 1 engine · 1 wording · 4 othershowhide 2026-02-01 B-Spec C-Spec Rear Sway Bars #39652suspension & brakes 2026-01-01 B-Spec Notes section cleanup #39062weight 2026-01-01 B-Spec 2026 BOP Recommendations #39475weight +25 lbs 2026-01-01 B-Spec Expire NLA Mazda 2 Headers #39582weight 2025-11-01 B-Spec Alternate Shift Cable Bushings and Rear Spring Seats #38472suspension & brakes 2025-11-01 B-Spec Fiesta BOP Adjustment #38847weight +55 lbs 2025-11-01 B-Spec Request to Remove Rear Shock From Spec Line Hyundai Accents/Kia #39017suspension & brakes 2025-11-01 B-Spec Update Honda Fit MT (07-08) Runoffs Eligibility #39060induction 2025-09-01 B-Spec Remove Asterisk from Rule 9 #38768other 2025-08-01 B-Spec Disabling 2 Pedal Shutdown #38354engine 2025-08-01 B-Spec Update Honda Fit MT (07-08) Intake Allowance #38530induction 2025-06-01 B-Spec Add Sedan spec lines for Hyundai & Kia #37537cars added 2025-06-01 B-Spec Shifter Bushing Questions. #38048suspension & brakes 2025-06-01 B-Spec Add Weapon R Intake to Honda Fit MT (09-14) Spec Line #38306induction 2025-06-01 B-Spec Update Rule 46 #38307suspension & brakes 2025-05-01 B-Spec Correct Hyundai/Kia Model Years #37943wording 2025-05-01 B-Spec 07-08 Honda Fit MT Requests #37974weight +50 lbs 2025-05-01 B-Spec Add B14 Kit Part # to Honda Fit (07-08) Spec line #38010other 2025-04-01 B-Spec 2025 BOP Recommendations #37520weight 2025-04-01 B-Spec Hyundai/Toyota Factory Rear Disc Models #37534weight 2025-04-01 B-Spec Request to Update the Spec line for Hyundai Accent and Kia Rio #37880suspension & brakes 2025-03-01 B-Spec Toyota Yaris Hatchback (12-18) rear disc brakes #37530suspension & brakes 2025-03-01 B-Spec Yaris Speed Sensor #37536other 2025-03-01 B-Spec Set Expiration Date For Fiat 500 #37689other
	Super Tour Feb 2025 CALCL252025-02-22												2:10.513Joseph Gersch · fastest of 4 · top 4 within 6.8s	2:10.054Thomas Lepper · fastest of 4 · top 4 within 7.4s	98.1Ali Naimi
127 rule changes (F5: 16, B-Spec: 111)21 suspension & brakes · 19 induction · 16 weight · 11 cars added · 10 tyres & wheels · 9 engine · 2 removed · 12 wording · 27 othershowhide 2025-02-01 B-Spec Remove Redundant Language from Notes Sections #37337induction 2025-02-01 B-Spec Expire designated spec lines #37517other 2025-02-01 B-Spec Set expiration date for Nissan Micra Cup Cars (Canadian) #37519other 2025-01-01 B-Spec Remove wheelbase from spec lines and replace with Restrictor #36074induction 2025-01-01 B-Spec Bilstein Rear Shock Request for Hyundai Accent/Kia Rio #36965suspension & brakes 2024-11-01 B-Spec Scion IA/Toyota Yaris/Mazda 2 DY chassis suspension #35780other 2024-11-01 B-Spec Clean up 07-08 Honda Fit AT Notes Section #36542induction 2024-08-01 B-Spec Update Tire Rules #35984tyres & wheels 2024-08-01 B-Spec BOP help for the automatic B-Specs #36161weight -50 lbs 2024-08-01 B-Spec Require hood pins #36233other 2024-08-01 B-Spec Sonic Caliper Pistons #36238suspension & brakes 2024-07-01 B-Spec Clean up (15-19) Honda Fit MT & CVT Notes Sections #36068induction 2024-07-01 B-Spec Set expiration date for Nissan Versa (09-11) #36069other 2024-07-01 B-Spec Delete Redundant Rule 25 #36075removed 2024-07-01 B-Spec Correct error for rear brakes of Hyundai/Kia #36174suspension & brakes 2024-06-01 B-Spec Add B14 Kit Part # to Sonic Spec line In #35969induction 2024-06-01 B-Spec Eliminate redundant sway bar end link part #s from notes In #35970suspension & brakes 2024-06-01 B-Spec Update Fiat 500 Spec line In #35990other 2024-06-01 B-Spec Update (15-19) Honda Fit #36067weight +25 lbs 2024-05-01 B-Spec Delete trim levels/update language for spec lines #35746other 2024-05-01 B-Spec Wheel Rules #36066tyres & wheels 2024-04-01 B-Spec Change restrictor from 30mm to 31mm (2015+ Honda Fit) and add 50# #34857induction 2024-04-01 B-Spec Wheel Offset and Spacer Revision #35466tyres & wheels 2024-04-01 B-Spec Set Expiration Date for Unused Spec Lines #35742engine 2024-03-01 B-Spec BOP Adjustment for Yaris iA, 2020+ Versa, and 07-08 Honda Fit #35382weight -125 lbs 2024-03-01 B-Spec 07-08 Honda Fit Rear Sway Bar part # #35473suspension & brakes 2024-02-01 B-Spec Eliminate Redundant Trans Cooler Rule #35353wording 2024-02-01 B-Spec Fix Sonic Hatchback MT Spec Line #35371other 2024-02-01 B-Spec Split Spec Line of Automatic and Manual 2nd Gen (09-14) Fit #35251cars added 2024-02-01 B-Spec Equalize Mazda 2 Headers and clean up spec line #35259weight 2024-02-01 B-Spec Rear Sway Bar Request for Nissan Versa and Versa Note 2013- #35323suspension & brakes 2024-01-01 B-Spec B-Spec Hankook Tire for Regionals #35055tyres & wheels 2024-01-01 B-Spec Update 12-19 Nissan Versa Spec Line & Adjust BOP #35074removed -60 lbs 2024-01-01 B-Spec Clarifying the ECU and Data Acquisition language #35236engine 2023-12-01 B-Spec Mazda 3i 2010-2013 5-Speed Manual Gear Ratios #34820other 2023-12-01 B-Spec Error Correction #34955engine 2023-11-01 B-Spec B-Spec Tire #35034tyres & wheels 2023-09-01 B-Spec Initial car classifications and spec lines #34461weight 2023-07-01 B-Spec Hyundai Accent Restrictor Plate #34331induction 2023-07-01 B-Spec Hyundai Accent 2012 Model #34332other 2023-06-01 B-Spec T5 Tire Options #33641tyres & wheels 2023-06-01 B-Spec Allow ZZP Sonic Aluminum Radiator 1.68 #33660induction 2023-06-01 B-Spec Fasteners for Bumper Caps #33797other 2023-06-01 B-Spec Allow CAN Bus Connection to Data Systems #33806engine 2023-06-01 B-Spec Request Ford Fiesta weight reduction 25lbs #33890weight -25 lbs 2023-06-01 B-Spec BoB Adjustments #34208weight -25 lbs 2023-06-01 B-Spec T5 Mazda 3 Spec Line Addition #33536cars added 2023-06-01 B-Spec T5 Ride Height Rules. #33552suspension & brakes 2023-06-01 B-Spec T5 Spring Allowance #33557suspension & brakes 2023-06-01 B-Spec T5 Wheel Minimum Weight #33558weight 2023-06-01 B-Spec Threaded Metal Inserts for Plastic Intake Manifolds #34164induction 2023-05-01 B-Spec T5 Rules Feedback #33595weight 2023-03-01 B-Spec Early Model Mini #33363other 2023-03-01 B-Spec Helper Versus Tender springs. #33866suspension & brakes 2023-02-01 B-Spec Split up Spec lines for Automatic/Manual 2nd Gen Fit #33292other 2023-01-01 B-Spec Request to Split Spec Lines for Automatic Models #33270weight 2023-01-01 B-Spec Tire Rule Request #33350tyres & wheels 2022-10-01 B-Spec Utilize the Data - Make BoP Changes #32179weight -225 lbs 2022-09-01 F5 Intake Boots Correction #33028induction 2022-08-01 B-Spec Request new Mazda Rear Swaybar #32769suspension & brakes 2022-08-01 F5 Ensure availability of ECU for Rotax engines #32695engine 2022-07-01 F5 Clarify stepped exhaust header references #32743engine 2022-06-01 F5 593 carb boot availability and oil pump clarification #32527induction 2022-05-01 B-Spec Request to Remove Part Numbers from Kia/Hyundai Spec Lines #32378induction 2022-03-01 B-Spec Request spring attachment #31351suspension & brakes 2022-03-01 B-Spec Limit Rear Camber to 1.75 Degrees Section 9.1.10.E.35 #31393suspension & brakes 2022-03-01 B-Spec Letter 31442 Part# Correction #32060wording 2022-03-01 F5 E&O class name #32194other 2022-02-01 B-Spec Request to Classify 2020-21 Versa S #30759cars added 2022-02-01 B-Spec Request to Classify the Toyota IA sedan & Scion IA Sedan for 2022 #31045cars added 2022-02-01 B-Spec Mazda 2 Undertray #31442suspension & brakes 2022-01-01 B-Spec Request to add 2007-2008 Honda Fit #30853cars added 2022-01-01 F5 Data Box Mounting Plate #31638other 2021-10-01 B-Spec Rules Clarification of Body and Camber Plates #30814suspension & brakes 2021-09-01 B-Spec Rules Clarification of Body and Camber Plates #30814suspension & brakes 2021-08-01 F5 Clarify allowable assisted shifting systems #30871wording 2021-08-01 F5 Request to correct terminology #30976tyres & wheels 2021-07-01 B-Spec B-Spec Mazda2 Header Update #30884weight 2021-06-01 B-Spec Transmission Cooler Requests #30079other 2021-06-01 B-Spec Request to classify the 07 Honda Fit #30083cars added 2021-06-01 B-Spec Request Ford Fiesta Eibach Rear Sway Bar Part Number 35143.320 #30340suspension & brakes 2021-06-01 B-Spec Restrictor rule #30474induction 2021-06-01 B-Spec Rear wipers on all cars #30585other 2021-06-01 F5 Request to Allow Rotax 593 HO Engine #30712engine 2021-04-01 B-Spec Allow 4 lug hub conversion to R60 and R61 MINI #29863suspension & brakes 2021-04-01 B-Spec Mazda2 header replacement #29944weight +50 lbs 2021-04-01 B-Spec Honda Fit Years on Spec Line #30078other 2021-04-01 B-Spec Hyundai/Kia restrictor size incorrect #30380induction 2021-04-01 B-Spec Clarify tire compound in rules #30387tyres & wheels 2021-03-01 B-Spec Spec Tire Recommendation #29480tyres & wheels 2021-03-01 B-Spec Make restrictor thickness unique for B Spec #30349induction 2021-02-01 B-Spec Request to Classify Hyundai Accent (RB) 2012-2019 #29484cars added 2021-02-01 B-Spec Countryman production years incorrect #29864other 2021-02-01 B-Spec Toyota Yaris Model Year Corrections #29896wording 2021-02-01 B-Spec Correction spec lines for ride height Mini Cooper all models #29952suspension & brakes 2021-02-01 B-Spec Request to Allow Removal of Stock Brake Dust Shields #29981suspension & brakes 2021-02-01 B-Spec Request to allow OBX header and restrictor to R55 Clubman 08-10 #30024induction 2020-12-01 B-Spec Request clarification of B14 shock package for any and all cars #29483suspension & brakes 2020-12-01 B-Spec Cleanup of spec lines #29495wording 2020-10-01 F5 Request to Update Suzuki Engine Years for F500 #29453engine 2020-09-01 B-Spec Allowance Versus Requirement for R56 Mini Cooper #29127induction 2020-07-01 F5 Request for Cockpit Adjustment of External Jetting Devices #28359other 2020-07-01 F5 Two Stroke Motors (reply to #28359 WDYT) #28816engine 2020-07-01 F5 Re letter requesting driver adjustable carb mixture #28840other 2020-07-01 F5 #28359 WDYT Request for Cockpit Adjustment #28875other 2020-06-01 B-Spec Request to change units on wheelbase for consistency with wording #28786wording 2020-05-01 B-Spec Transmission cooler for automatic equipped cars #28171weight 2020-05-01 B-Spec Spring Update for all models #28384suspension & brakes 2020-05-01 B-Spec Request to Cleanup Sunroof Wording #28401wording 2020-05-01 B-Spec B-Spec Balance of Performance based on 2018 and 2019 seasons #28394weight -25 lbs 2020-03-01 B-Spec Request for Model Years Updating #27850other 2020-03-01 B-Spec Request to classify Min Cooper models #27861cars added 2020-03-01 B-Spec remove fog lights #27947wording 2020-03-01 B-Spec add sonic sedan #27948cars added 2020-02-01 B-Spec Request for Automatic Transmission Inclusion #27686other 2020-02-01 B-Spec Request to Add Transmission Coolers to Automatics #27687wording 2020-01-01 B-Spec Add Yaris Sedan #26797cars added 2020-01-01 B-Spec Add 2011-2016 Fiesta Sedan #26798cars added 2020-01-01 B-Spec add 2015-2019 Kia Rio #26799other 2020-01-01 B-Spec Error and Omissions #27858induction 2020-01-01 F5 Change 600cc restrictor size #27883induction 2019-12-01 B-Spec Request for Correction of Production Years for Mini Cooper #27226wording 2019-10-01 B-Spec Request for Corrections to 9.1.10 E Item #27 D and E #27224wording 2019-10-01 B-Spec Remove wording in the B-spec rules #27388wording 2019-10-01 B-Spec Request to add 2013 Honda Fit model year #27491other 2019-08-31 F5 Request for Weight Increase for Motorcycle Powered Cars #27214weight +25 lbs 2019-07-01 B-Spec Request to allow OBX Header for 2007-10 Mini Cooper #26977other
	Super Tour Apr 2019 ST19APR262019-04-26
4 earlier rule changes on record, in force before Super Tour Apr 2019 (from 2019)2 cars added · 2 wordingshowhide 2019-03-01 B-Spec Request to add B-Spec to GCR 9.3.26 fuel cell #26132wording 2019-01-01 B-Spec Request to classify Canadian Nissan Micra Cup cars #25216cars added 2019-01-01 B-Spec Request updated Toyota Yaris Spec Lines #25483cars added 2019-01-01 B-Spec Update wording of exhaust #26022wording

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. 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.