BoP Lab / Buttonwillow Raceway Park
F5 vs F500 vs SRF vs FF pace at Buttonwillow Raceway Park
Quickest here: FF 1:51.118 Eric Poulsen, Super Tour Feb 2025 race
| Event | F5 | F500 | SRF | FF | |||||||||||||
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| 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 | 1:53.098Edward Erlandson · fastest of 2+1.054s (+0.94%) | 1:54.741Edward Erlandson · fastest of 2+3.623s (+3.26%) | 133.7Edward Erlandson+19.0 mph (+16.5%) | ||||||||||||||
6 rule changes (SRF: 3, FF: 3)3 tyres & wheels · 1 engine · 1 wording · 1 other · FF clarifies alternative tire eligibility: homologated 1989 or earlier with rocker or outboard suspension all four corners; push-rod/pull-rod cars may seek approval. · SRF3 adds HD Oil Cooler P/N G1148500 option alongside standard P/N G480503, no fan permitted. · FF adds rocker arm and outboard suspension cars option to use Hoosier bias ply slicks or VFF tyres; clarifies mixing rules. · SRF drivers with disabilities may modify seat and controls for safety and comfort with SCCA approval, noted in logbook, for that driver only. · SRF SADEV-SRF3 6-speed sequential transmission: effective date clarified to 1 April 2025 onward. · FF adds alternative tire options for older cars with rocker arm or outboard suspension: bias ply slicks or VFF radials.show
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| Super Tour Feb 2025 CALCL252025-02-22 | 1:52.044Eric Poulsen · only car | 1:51.118Eric Poulsen · only car | 114.7Eric Poulsen | ||||||||||||||
59 earlier rule changes on record, in force before Super Tour Feb 2025 (from 2019)11 engine · 6 tyres & wheels · 3 weight · 2 aero · 2 cars added · 2 suspension & brakes · 1 induction · 23 wording · 9 other · FF and FC sequential gearbox weight penalty reduces from 25 lbs to 10 lbs minimum weight addition. · FF Honda Fit pistons: OEM 0.25mm oversize PN 13020-RB7-Z00 or Fast Forward PN FF800-110 now both allowed; standard diameter 73.240mm (2.8835 inches), minimum weight 198.0g. · FF EGR blanking plate rule clarified: VTEC activation valve must be retained and functioning, no modifications permitted. · SRF3 air filter rule removes K&N RC-9160 option, specifies Weems P/N WM301020 only. · SRF Wilwood vented rotor minimum thickness increases to 13.25mm, 0.522 inches. · SRF3 Hoosier decal placement changed from four logos on nose and tail to three logos on sides and center front. · FE and SRF protest fee rules redirected to GCR section 8.3.1.D for fees and procedure. · SRF Hoosier contingency decal requirement reduced from four decals in specific locations to three decals with simplified placement. · SRF wet tyres: front P185/60R13 H20 or W2 and rear P205/60R13 H20 or W2 removed; front P185/65R13 W2 and rear P205/60R13 W2 now required. Hoosier decal placement specified. · FF Honda Fit gains Fast Forward oversize piston ring option PN FF800-100 as alternative to Riken or Nippon. · SRF rain/brake light must be Super Bright LEDs Inc. P/N PT-STRB-R24; secondary filament must connect to rain light switch. · SRF brake light must be Super Bright LEDs Inc. P/N PT-STRB-R24, with SCCA Enterprises P/N 180427A pigtail and strobing rain light kit. · SRF adds mandatory front brake ducts 12–36 inches, throttle pedal heel-toe extension, braided stainless flex lines, camber limit 5.0 degrees, radiator opening height 3½ ± ½ inches, rear shift cable clamp P/N WM302007A. · SRF radiator options expanded: Enterprises P/N 480465 with baffle 480464, 480466, or Automotive 1R698 and CU698 allowed if cross-reference equivalent. · SRF wet front tyre changes to Hoosier P/N 46100 P185/60R13 H20 or W2 with 2.5" ground clearance. · SRF front W2 rain tyre Hoosier part number changes from 46100 to 46101 P185/65R13. · FF Honda Fit engine adds Fast Forward part number alternatives for intake, exhaust, oil system, and scavenge pump components. · SRF removes 1985 Renault Alliance solid front rotor option; restrictor sizes decrease 1mm for newer Kawasaki and multi-brand engines; minimum weights increase to 1100 lbs. · F500 Rotax 493 and 593 intake boots: removed Moto Tassinari V3124-873B-2 from 493/593 non-HO allowance, added Moto Tassinari V3120-794A-2 option for non-HO. · F500 Rotax engines now permit Ingi Tech Sparker ignition DCP-CDI-P2 as alternate ECU. · F500 clarifies stepped diameter exhaust headers prohibited except at cylinder head flange area. · F500 Rotax 593 intake boot options clarified; oil injection pump removal now permitted. · SRF tire rule wording clarified: tires must be run as delivered. · SRF brake rotor minimum thickness reduced from 13.25 mm to 12.20 mm; seals and air filter specs clarified. · F500 Majors and Runoffs cars must install AIM part #X47KPFSOLO2R0 data box mount for Solo or Solo 2. · F5 cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs. · 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… · F5 clarifies mechanical shifting only; throttle-cut and flat-shifter devices permitted if driver retains full control. · F5 single-seat open-wheel cars: rigid suspension becomes limited suspension in class definition. · 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. · F500 Rotax 593 HO engine now permitted; 875 lbs minimum weight, MA0242SP1020A or MA0242SP1063A restrictor, specific intake boots and piston required. · SRF3 alternator pulley specified as P/N G902130 or G902130A, minimum 12oz. · FF block relief permitted only as needed to fit an allowed crankshaft. · SRF and SRF3 mandatory identification revised: removed Ford Performance and Blue Oval decals, added Hoosier logo placement. · FF class cylinder head now permits optional coolant bleed line pipe thread fitting to swirl tower. · FF Honda LC1 ECU supplied by HPD is permitted effective 12/1/2020 with HPD lambda sensor. · SRF rear springs limited to P/N 280390 only, previous part numbers no longer allowed; ground clearance wording clarified. · F500 Suzuki GSXR600 engine years extended from 2003-2013 to 2003-2019. · FF Honda LC1 ECU implementation date clarified to pending, contingent on SCCA receiving sufficient support materials. · F5 request to adjust external jetting device cockpit control denied; no rule change made. · F5 driver adjustable carburettor mixture: refer to separate Fastrack letter #28359 for ruling. · F5 cockpit adjustment request response published in Fastrack letter 28359. · SRF Penske shock P/N 280396 bump stop P/N 280407 becomes mandatory, maximum one per shock, effective 05/01/2020. · FF Kent Engine alternator becomes optional instead of not required. · FF permits HPD LC1 ECU with lambda sensor; E1 ECU no longer supported but existing units may continue. · FF rain tyres now allow Hoosier W3 Radial 185/60R13 front and 205/60R13 rear. · F500 Honda CBR600RR, Suzuki GSXR600, Yamaha R6 restrictor reduced to 28mm from 29mm. · SRF rain and brake rule supersedes GCR 9.3.32.B.2 effective 1/1/2024 through 12/31/2024. · 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. · F500 Honda CBR600RR, Suzuki GSXR600, and Yamaha R6 minimum weights increase to 900 lbs. · SRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102. · FF Honda Fit cylinder honing increased to 73.315mm and oversize pistons PN 13020-RB7-Z00 now permitted with matching ring packs. · FF intake manifold thermal wrap now permitted if easily removable for inspection; no coating allowed. · FF clarifies coolant and oil catch tank capacity requirements: coolant minimum one U.S. pint, oil minimum one U.S. quart per system.show
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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.