BoP Lab / Buttonwillow Raceway Park

FE vs F5 vs F6 vs FX pace at Buttonwillow Raceway Park

Lap times across years say as much about the weather as the class. % of FE is each class's best lap as a share of FE's on the same day, so the conditions drop out: 100% is level, less is quicker, and a move in it is the class getting faster or slower against the field.

Quickest here: FE 1:47.040 Brandon Chappell, Super Tour Apr 2018 race · F5 1:51.129 Jeff Jorgenson, Super Tour Apr 2017 race · F6 1:59.670 Jeff Jorgenson, Super Tour Feb 2024 race · FX 1:48.518 Bill Weaver, Super Tour Feb 2020 race

% of FELap times

FEF5F6FXsolid race · dashed qualifying · slower is lower

FEF5F6FXsolid race · dashed qualifying · each class's best lap as a share of FE's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker

	Event	FE			F5					F6					FX
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs FE	% of FE	Qual best	Race best	Trap	vs FE	% of FE	Qual best	Race best	Trap	vs FE	% of FE
	Super Tour Feb 2024 CALCL242024-02-23									2:00.926Jeff Jorgenson · only car	1:59.670Jeff Jorgenson · only car	104.7Jeff Jorgenson
22 rule changes (FE: 8, F5: 5, FX: 9)6 engine · 4 weight · 3 induction · 1 aero · 1 suspension & brakes · 1 tyres & wheels · 6 othershowhide 2024-01-01 FE Update FE Rain Light Rule #34707other 2024-01-01 FE FE/FE2 rule update #35269other 2023-11-01 FX FM Rules Update #34841other 2023-06-01 FX USF2000 Van Diemen with Mazda MZR LF-DE 2.0L in FC #34329weight 2023-04-01 FE Update FE SADEV Transmission Rule #33883other 2023-02-01 FX E&O - Remove references to FB and FM in GCR section 1.4.2.D #33725other 2022-12-01 FX Reclassify 2010-2017 Formula Renault 2.0 as a spec line car in FA #33395weight 2022-10-01 FE Brake bias adjuster clarification #33084suspension & brakes 2022-10-01 FE FE Front and Rear Wing Update & Clarification #33089aero 2022-09-01 F5 Intake Boots Correction #33028induction 2022-09-01 FE Engine Heat Shield & Insulation #33019engine 2022-08-01 F5 Ensure availability of ECU for Rotax engines #32695engine 2022-08-01 FX Pro Formula F2000/USF2000 Transmission E&O #32823weight 2022-08-01 FX Formula Mazda Minimum Weight #33010weight 2022-08-01 FX Formula Mazda Spec Line E&O Corrections #33011engine 2022-07-01 F5 Clarify stepped exhaust header references #32743engine 2022-07-01 FX Formula Renault 2.0 (10-17) Intake Restrictor #32745induction 2022-07-01 FX Allow Performance Electronics PE3-8400 for USF2000 MZR #32767engine 2022-06-01 F5 593 carb boot availability and oil pump clarification #32527induction 2022-06-01 FE Update FE/FE2 Tire Rule #32613tyres & wheels 2022-06-01 FE Master cylinder clarification #32669engine 2022-03-01 F5 E&O class name #32194other
	Super Tour Feb 2022 CALCL222022-02-17														1:48.641Max Parker · fastest of 3 · top 3 within 5.1s-0.679s (-0.62%)	1:50.238Max Parker · fastest of 3 · top 3 within 3.9s+1.720s (+1.58%)	117.4Terrance Carraher-12.5 mph (-9.6%)
31 rule changes (FE: 8, F5: 9, FX: 14)9 tyres & wheels · 5 cars added · 3 engine · 2 aero · 2 suspension & brakes · 1 induction · 2 wording · 7 othershowhide 2022-02-01 FX FM Rule Set Clarification #31881tyres & wheels 2022-02-01 FX E&O F4 Tires #31940tyres & wheels 2022-02-01 FX E&O USF2000 Tube Frame #31951tyres & wheels 2022-02-01 FX URGENT - FX- Formula Renault Tire #32058tyres & wheels 2022-01-01 F5 Data Box Mounting Plate #31638other 2021-12-01 FE Two FE2 Rule Updates #31524other 2021-08-01 F5 Clarify allowable assisted shifting systems #30871wording 2021-08-01 F5 Request to correct terminology #30976tyres & wheels 2021-08-01 FX Rules Adjustment #30950tyres & wheels 2021-07-01 FE FE Tire Rule Changes #30754tyres & wheels 2021-07-01 FE Radiator Screens Clarification #30792wording 2021-06-01 F5 Request to Allow Rotax 593 HO Engine #30712engine 2021-06-01 FE FE Radiator Screens #30575other 2021-06-01 FX FX/FRP Tire Rule #30723tyres & wheels 2021-05-01 FX Classify the 2000-2009 Formula Renault 2.0 / Fran-Am 2000 #30460cars added 2021-01-01 FX Request for Car Classification to Compete in Formula X #29933cars added 2020-12-01 FE FE / FE2 Spring Updates #29689suspension & brakes 2020-12-01 FX Update specifications for FormulaSPEED cars #29674induction 2020-10-01 F5 Request to Update Suzuki Engine Years for F500 #29453engine 2020-10-01 FE FE Gurney Flap Spec Update #29445aero 2020-09-01 FX Follow up to to Letter#28991 Request for FX classification #29281cars added 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 2020-07-01 FX Request to be added to FX group #28991other 2020-06-01 FE FE Gurney flap wicker clarification #28885aero 2020-05-01 FE FE spring rule update changed to November 1, 2020 #28814suspension & brakes 2020-04-01 FX Request to classify FSV in FX #28057cars added 2020-04-01 FX Classify FormulaSPEED in FX #28715cars added 2020-03-01 FX Request to remove tire marking language from FM #28415tyres & wheels
	Super Tour Feb 2020 ST20FEB212020-02-21														1:49.320Steve Martin · fastest of 5 · top 5 within 6.7s	1:48.518Bill Weaver · fastest of 5 · top 5 within 6.8s	129.9Steve Martin
9 rule changes (FE: 6, F5: 2, FX: 1)3 weight · 2 induction · 2 tyres & wheels · 1 suspension & brakes · 1 othershowhide 2020-02-01 FX Change to FX Table 1 #28322induction 2020-01-01 F5 Change 600cc restrictor size #27883induction 2020-01-01 FE Request for FE / FE2 preparation rules update #27722weight 2019-12-01 FE FE / FE2 Update Rules #27624weight 2019-10-01 FE FE Wet Tire E&O #27365tyres & wheels 2019-08-31 F5 Request for Weight Increase for Motorcycle Powered Cars #27214weight +25 lbs 2019-07-01 FE FE Tire Update #27029tyres & wheels 2019-05-31 FE FE Anti-Roll Bar Clarification #26912suspension & brakes 2019-05-31 FE FE / FE2 Updated Bubble Tail Rule #26913other
	Super Tour Apr 2019 ST19APR262019-04-26	1:49.749Jeff Read · only car+2.153s (+2.00%)	1:50.132Jeff Read · fastest of 2+3.092s (+2.89%)	119.6Joe Reppert
1 rule change (FE: 1)1 tyres & wheelsshowhide 2019-03-01 FE Request to Update Hoosier Rain Tire Part Number for the FE cars #26235tyres & wheels
	Super Tour Apr 2018 BUTTRA182018-04-27	1:47.596John Yeatman · fastest of 3 · top 3 within 13.1s-1.154s (-1.06%)	1:47.040Brandon Chappell · fastest of 3 · top 3 within 11.2s-1.159s (-1.07%)
No rule changes on record between these events
	Super Tour Apr 2017 BUTTRA172017-04-28	1:48.750Brandon Aleckson · fastest of 2	1:48.199Brandon Aleckson · fastest of 2		1:52.268Jeff Jorgenson · fastest of 2	1:51.129Jeff Jorgenson · fastest of 2		+2.930squal +3.518s	102.7%qual 103.2%

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