BoP Lab / Buttonwillow Raceway Park

FM vs SRF vs FE vs FX pace at Buttonwillow Raceway Park

Quickest here: FM 1:45.954 Mike Anderson, Super Tour Apr 2018 race · SRF 1:44.060 Vince Balch, Super Tour Apr 2017 qualifying · FE 1:47.040 Brandon Chappell, Super Tour Apr 2018 race · FX 1:48.518 Bill Weaver, Super Tour Feb 2020 race

Lap times% of FM

FMSRFFEFXsolid race · dashed qualifying · slower is lower

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

	Event	FM			SRF					FE					FX
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs FM	% of FM	Qual best	Race best	Trap	vs FM	% of FM	Qual best	Race best	Trap	vs FM	% of FM
	Super Tour Feb 2022 CALCL222022-02-17														1:48.641Max Parker · fastest of 3 · top 3 within 5.1s-0.679s (-0.62%)	1:49.461Max Parker · fastest of 3 · top 3 within 4.6s+0.943s (+0.87%)	117.4Terrance Carraher-12.5 mph (-9.6%)
30 rule changes (SRF: 8, FE: 8, FX: 14)7 cars added · 5 tyres & wheels · 2 aero · 1 engine · 1 suspension & brakes · 10 wording · 4 other · Formula Mazda FX rule reference updated to current specifications document; tire marking no longer required. · FX Formula 4 tire choice unrestricted; must provide FIA certification rules upon request. · FX USF2000 Tube Frame front tyre changes from Hoosier radial 20.5 x 7.0 x 13 to any Hoosier 20.5 x 7.0 x 13. · FX Formula Renault 2.0 (00-09) and (10-17) tire choice unrestricted; no other component alterations except repairs. · SRF wet tyres front P185/65R13 W2 option added; air box clarified as-delivered; SRF3 restrictor plate G301048 mandatory Jan 1 2022; P2 motorcycle engines up to 1005cc with 35mm restrictor, 2009+ stock 1075 lbs, 2008 stock 1025 lbs, modifie… · FX USF2000 Tube Frame gains Hoosier radial tyre option, FC-compliant shocks, Wilwood brakes, and Bosch spark plugs. · SRF wet tyres add Hoosier W2 option alongside existing H20 from October 4, 2021. · SRF adds SADEV-SRF3 6-speed sequential transmission option with ratios 3.0–0.92:1 and 3.20 final drive. · SRF seal requirements clarified: seals now must be on driveline components in designated locations; unsealed components removed and inspected by CSR or Enterprises rather than engine shipped for testing. · FE removes qualifying tire marking requirements and rain tire set rules; renumbers tire warmer prohibition. · FE radiator screens may not protrude more than ¼ inch in front of the outside vertical plane of the sidepods. · FE radiator screens now allowed, maximum ¼ inch from sidepod front vertical plane. · FX USF2000 Tube Frame now allows any Hoosier radial tire 20.5×7.0×13 front, 22.5×8.0×13 rear. · SRF3 alternator pulley specified as P/N G902130 or G902130A, minimum 12oz. · Formula Renault 2.0 / Fran-Am 2000 added to FX class at 1250 lbs with 8-inch front, 10-inch rear wheels, sealed engine. · SRF and SRF3 mandatory identification revised: removed Ford Performance and Blue Oval decals, added Hoosier logo placement. · FX adds 2010–2017 Formula Renault 2.0, must comply with Table 1 notes. · FE front springs change to 800 lbs Hypercoil WM203013 Silver; rear to 900 lbs Hypercoil WM203014 Silver. · FX FormulaSPEED FS2.0 now references online specifications instead of requiring World Speed Inc. documentation by April 2020. · SRF rear springs limited to P/N 280390 only, previous part numbers no longer allowed; ground clearance wording clarified. · FE Gurney flaps clarified: front wing secondary only at 0.500" ±0.030", rear wing at 0.250" ±0.030". · Formula Ireland / Formula FX added to FX class, must comply with Table 1 notes. · Formula Ireland/Formula FX cars pending specification submission for possible FX table addition. · FE Gurney flap wicker bill clarified: permitted on front wing secondary elements only, not main plane. · FE2 and FE spring part numbers WM203013 front and WM203014 rear required date moved to November 1, 2020. · SRF Penske shock P/N 280396 bump stop P/N 280407 becomes mandatory, maximum one per shock, effective 05/01/2020. · Ex-Pro Formula Super Vee added to FX with 1600cc VW engine, 1190 lb minimum weight, 6-inch front and 8-inch rear wheels. · FormulaSPEED with 2.0L Mazda MZR engine, 8in front/10in rear wheels, adjustable dual rear planes, 1350 lbs moves from FA to FX. · FX Formula Mazda no longer requires tire marking; must comply with December 2019 GCR rules.showhide 2022-02-01 FX FM Rule Set Clarification #31881wordingwordingFormula Mazda FX rule reference updated to current specifications document; tire marking no longer required. 2022-02-01 FX E&O F4 Tires #31940tyres & wheelsadded · tyres & wheelsFX Formula 4 tire choice unrestricted; must provide FIA certification rules upon request. 2022-02-01 FX E&O USF2000 Tube Frame #31951tyres & wheelstyres & wheelsFX USF2000 Tube Frame front tyre changes from Hoosier radial 20.5 x 7.0 x 13 to any Hoosier 20.5 x 7.0 x 13. 2022-02-01 FX URGENT - FX- Formula Renault Tire #32058tyres & wheelsadded · tyres & wheelsFX Formula Renault 2.0 (00-09) and (10-17) tire choice unrestricted; no other component alterations except repairs. 2021-12-01 FE Two FE2 Rule Updates #31524other 2021-12-01 SRF Three Updates to SRF Rules #31523otherotherSRF wet tyres front P185/65R13 W2 option added; air box clarified as-delivered; SRF3 restrictor plate G301048 mandatory Jan 1 2022; P2 motorcycle engines up to 1005cc with 35mm restrictor, 2009+ stock 1075 lbs, 2008 stock 1025 lbs, modifie… 2021-08-01 FX Rules Adjustment #30950otheraddedFX USF2000 Tube Frame gains Hoosier radial tyre option, FC-compliant shocks, Wilwood brakes, and Bosch spark plugs. 2021-08-01 SRF SRF Wet Tires #30849tyres & wheelsadded · tyres & wheelsSRF wet tyres add Hoosier W2 option alongside existing H20 from October 4, 2021. 2021-08-01 SRF SADEV-SRF3 Transmission #30926cars addedaddedSRF adds SADEV-SRF3 6-speed sequential transmission option with ratios 3.0–0.92:1 and 3.20 final drive. 2021-08-01 SRF SRF Update Maintenance, Repairs and Seals #30961wordingwordingSRF seal requirements clarified: seals now must be on driveline components in designated locations; unsealed components removed and inspected by CSR or Enterprises rather than engine shipped for testing. 2021-07-01 FE FE Tire Rule Changes #30754wordingwordingFE removes qualifying tire marking requirements and rain tire set rules; renumbers tire warmer prohibition. 2021-07-01 FE Radiator Screens Clarification #30792wordingwordingFE radiator screens may not protrude more than ¼ inch in front of the outside vertical plane of the sidepods. 2021-06-01 FE FE Radiator Screens #30575aeroadded · aeroFE radiator screens now allowed, maximum ¼ inch from sidepod front vertical plane. 2021-06-01 FX FX/FRP Tire Rule #30723tyres & wheelsadded · tyres & wheelsFX USF2000 Tube Frame now allows any Hoosier radial tire 20.5×7.0×13 front, 22.5×8.0×13 rear. 2021-06-01 SRF SRF3 Alternator Pulley #30684engineadded · engineSRF3 alternator pulley specified as P/N G902130 or G902130A, minimum 12oz. 2021-05-01 FX Classify the 2000-2009 Formula Renault 2.0 / Fran-Am 2000 #30460cars addedaddedFormula Renault 2.0 / Fran-Am 2000 added to FX class at 1250 lbs with 8-inch front, 10-inch rear wheels, sealed engine. 2021-03-01 SRF Mandatory identification: #30223wordingwordingSRF and SRF3 mandatory identification revised: removed Ford Performance and Blue Oval decals, added Hoosier logo placement. 2021-01-01 FX Request for Car Classification to Compete in Formula X #29933cars addedaddedFX adds 2010–2017 Formula Renault 2.0, must comply with Table 1 notes. 2020-12-01 FE FE / FE2 Spring Updates #29689suspension & brakessuspension & brakesFE front springs change to 800 lbs Hypercoil WM203013 Silver; rear to 900 lbs Hypercoil WM203014 Silver. 2020-12-01 FX Update specifications for FormulaSPEED cars #29674wordingwordingFX FormulaSPEED FS2.0 now references online specifications instead of requiring World Speed Inc. documentation by April 2020. 2020-12-01 SRF SRF Shocks, Springs and Ride Height. #29688otherotherSRF rear springs limited to P/N 280390 only, previous part numbers no longer allowed; ground clearance wording clarified. 2020-10-01 FE FE Gurney Flap Spec Update #29445aeroaeroFE Gurney flaps clarified: front wing secondary only at 0.500" ±0.030", rear wing at 0.250" ±0.030". 2020-09-01 FX Follow up to to Letter#28991 Request for FX classification #29281cars addedaddedFormula Ireland / Formula FX added to FX class, must comply with Table 1 notes. 2020-07-01 FX Request to be added to FX group #28991cars addedaddedFormula Ireland/Formula FX cars pending specification submission for possible FX table addition. 2020-06-01 FE FE Gurney flap wicker clarification #28885wordingwordingFE Gurney flap wicker bill clarified: permitted on front wing secondary elements only, not main plane. 2020-05-01 FE FE spring rule update changed to November 1, 2020 #28814wordingwordingFE2 and FE spring part numbers WM203013 front and WM203014 rear required date moved to November 1, 2020. 2020-05-01 SRF SRF Bump Stop Correction #27019wordingwordingSRF Penske shock P/N 280396 bump stop P/N 280407 becomes mandatory, maximum one per shock, effective 05/01/2020. 2020-04-01 FX Request to classify FSV in FX #28057cars addedaddedEx-Pro Formula Super Vee added to FX with 1600cc VW engine, 1190 lb minimum weight, 6-inch front and 8-inch rear wheels. 2020-04-01 FX Classify FormulaSPEED in FX #28715cars addedaddedFormulaSPEED with 2.0L Mazda MZR engine, 8in front/10in rear wheels, adjustable dual rear planes, 1350 lbs moves from FA to FX. 2020-03-01 FX Request to remove tire marking language from FM #28415wordingwordingFX Formula Mazda no longer requires tire marking; must comply with December 2019 GCR rules.
	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
12 rule changes (SRF: 5, FE: 6, FX: 1)3 tyres & wheels · 2 aero · 2 weight · 1 cars added · 1 suspension & brakes · 3 wording · Pro Formula F 2000 and USF2000 Tube Frame engine and car rules simplified; FC rules and FRP MAZDA MZR F2000 specs now apply directly. · FE2 Mazda 2.0L MZR engine now permitted in all SCCA events at 1250 lbs minimum; FE 2.3L becomes Regional Only through 2019 Runoffs. · SRF rain and brake rule supersedes GCR 9.3.32.B.2 effective 1/1/2024 through 12/31/2024. · FE minimum weight rises to 1270 lbs; FE2 minimum weight rises to 1270 lbs; new spring options added; tire warmers prohibited. · SRF adds tire warmer prohibition and specifies Hoosier dry and wet tire part numbers. · SRF front nose weight minimum reduced from 35 to 32 lbs. · SRF2 becomes Regional Only; SRF3 nomenclature changed from GEN3 to Ford 1.6L conversion; SRF and SRF3 no longer compete together for points. · FE Hoosier wet rear tire width increases from 7.5 to 8.0 inches, part number 44196 W3. · FE removes American Racer tires, mandates Hoosier dry tires 22.0 X 8.0-13 and 22.0 X 10.0-13, wet tires 22.0 X 7.5-13 and 22.0 X 9.0-13. · SRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102. · FE anti-roll bar links may be removed one per end for safety, but bars must stay connected. · FE and FE2 Enterprise bubble tail P/N WM138014 newly allowed for both classes.showhide 2020-02-01 FX Change to FX Table 1 #28322wordingunclearPro Formula F 2000 and USF2000 Tube Frame engine and car rules simplified; FC rules and FRP MAZDA MZR F2000 specs now apply directly. 2020-01-01 FE Request for FE / FE2 preparation rules update #27722cars addedaddedFE2 Mazda 2.0L MZR engine now permitted in all SCCA events at 1250 lbs minimum; FE 2.3L becomes Regional Only through 2019 Runoffs. 202-01-01 SRF SRF Rain / Brake Rule - BoD approved as follows #34958wordingwordingSRF rain and brake rule supersedes GCR 9.3.32.B.2 effective 1/1/2024 through 12/31/2024. 2019-12-01 FE FE / FE2 Update Rules #27624weightslower · weightFE minimum weight rises to 1270 lbs; FE2 minimum weight rises to 1270 lbs; new spring options added; tire warmers prohibited. 2019-12-01 SRF SRF Tire Warmer Rule #27622tyres & wheelstyres & wheelsSRF adds tire warmer prohibition and specifies Hoosier dry and wet tire part numbers. 2019-12-01 SRF SRF / SRF3 Nose Weight Reduction #27706weightfaster · weightSRF front nose weight minimum reduced from 35 to 32 lbs. 2019-12-01 SRF SRF / SRF3 Majors & Regional Class Updates #27723wordingwordingSRF2 becomes Regional Only; SRF3 nomenclature changed from GEN3 to Ford 1.6L conversion; SRF and SRF3 no longer compete together for points. 2019-10-01 FE FE Wet Tire E&O #27365tyres & wheelstyres & wheelsFE Hoosier wet rear tire width increases from 7.5 to 8.0 inches, part number 44196 W3. 2019-07-01 FE FE Tire Update #27029tyres & wheelstyres & wheelsFE removes American Racer tires, mandates Hoosier dry tires 22.0 X 8.0-13 and 22.0 X 10.0-13, wet tires 22.0 X 7.5-13 and 22.0 X 9.0-13. 2019-07-01 SRF SRF Dash Windscreen Kit #27028aeroadded · aeroSRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102. 2019-05-31 FE FE Anti-Roll Bar Clarification #26912suspension & brakessuspension & brakesFE anti-roll bar links may be removed one per end for safety, but bars must stay connected. 2019-05-31 FE FE / FE2 Updated Bubble Tail Rule #26913aeroadded · aeroFE and FE2 Enterprise bubble tail P/N WM138014 newly allowed for both classes.
	Super Tour Apr 2019 ST19APR262019-04-26	1:49.608Mike Anderson · fastest of 3 · top 3 within 5.6s+3.285s (+3.09%)	1:49.409Mike Anderson · fastest of 3 · top 3 within 4.9s+3.455s (+3.26%)	121.2Mike Anderson						1:49.749Jeff Read · only car+2.153s (+2.00%)	1:50.132Jeff Read · fastest of 2+3.092s (+2.89%)	119.6Joe Reppert	+0.723squal +0.141s	100.7%qual 100.1%
1 rule change (FE: 1)1 tyres & wheels · FE Hoosier rain tyre part numbers updated: front 44195 W3, rear 44217 W3.showhide 2019-03-01 FE Request to Update Hoosier Rain Tire Part Number for the FE cars #26235tyres & wheelstyres & wheelsFE Hoosier rain tyre part numbers updated: front 44195 W3, rear 44217 W3.
	Super Tour Apr 2018 BUTTRA182018-04-27	1:46.323Mike Anderson · fastest of 9 · top 5 within 2.1s+0.367s (+0.35%)	1:45.954Mike Anderson · fastest of 9 · top 5 within 3.3s-0.317s (-0.30%)							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%)		+1.086squal +1.273s	101.0%qual 101.2%
No rule changes on record between these events
	Super Tour Apr 2017 BUTTRA172017-04-28	1:45.956Mike Anderson · fastest of 8 · top 5 within 2.0s	1:46.271Mike Anderson · fastest of 10 · top 5 within 2.1s		1:44.060Vince Balch · fastest of 8 · top 5 within 18.6s	2:01.122Mike Miserendino · fastest of 7 · top 5 within 1.8s		+14.851squal -1.896s	114.0%qual 98.2%	1:48.750Brandon Aleckson · fastest of 2	1:48.199Brandon Aleckson · fastest of 2		+1.928squal +2.794s	101.8%qual 102.6%

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