BoP Lab / Buttonwillow Raceway Park
FV vs SRF3 vs FC vs AS pace at Buttonwillow Raceway Park
Quickest here: FV 1:58.898 Mace Gjerman, Cal Club 2026 race · SRF3 1:50.233 Caleb Shrader, Cal Club 2025 qualifying · FC 1:45.137 Robert Armington, Cal Club 2026 qualifying · AS 1:55.849 Roger Eagleton, Cal Club 2025 race
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| Qual best | Race best | Trap | Qual best | Race best | Trap | vs FV | % of FV | Qual best | Race best | Trap | vs FV | % of FV | Qual best | Race best | Trap | vs FV | % of FV | |||
| Cal Club 2026 CALCL262026-02-21 | 2:02.562Gavin Sweeney · fastest of 7 · top 5 within 3.3s+0.208s (+0.17%) | 1:58.898Mace Gjerman · fastest of 7 · top 5 within 6.0s-2.299s (-1.90%) | 124.6Gavin Sweeney+21.2 mph (+20.5%) | 1:50.913Asad Nikadambaev · fastest of 27 · top 5 within 1.1s+0.680s (+0.62%) | 1:52.070Asad Nikadambaev · fastest of 27 · top 5 within 0.8s+1.245s (+1.12%) | 138.9Paul Marino+20.7 mph (+17.5%) | -6.828squal -11.649s | 94.3%qual 90.5% | 1:45.137Robert Armington · fastest of 4 · top 4 within 25.0s-4.930s (-4.48%) | 1:45.314Robert Armington · fastest of 4 · top 4 within 12.9s-3.208s (-2.96%) | 147.5Bill Wallschlaeger+33.0 mph (+28.9%) | -13.584squal -17.425s | 88.6%qual 85.8% | 1:56.812Ross Murray · fastest of 2+0.367s (+0.32%) | 1:56.314Ross Murray · fastest of 2+0.465s (+0.40%) | 135.2Ross Murray+26.5 mph (+24.4%) | -2.584squal -5.750s | 97.8%qual 95.3% | ||
17 rule changes (SRF3: 4, FC: 2, AS: 11)3 weight · 2 induction · 1 cars added · 10 wording · 1 other · AS Chevy LS adds Edelbrock Performer RPM 71187 intake manifold with MSD 6014 ignition and 4776 Holly carburetor as spec line option. · AS Ford Mustang Restricted Prep engines lose 3 mm restrictor plate, from 64 mm to 61 mm. · FC USF2000 Tube Frame may use Hewland LD200 4-speed H-pattern as alternative to Hewland JL-200 5-speed sequential. · FC F2000 Metrik ZF2 minimum weight reduced to 1220 lbs. · AS Ford Mustang GT 94-04 Restricted Prep Engine now permits Ford Motorsport M-6250-F303 camshaft. · AS Cadillac CTS-V 04-07 Restricted Prep weight reduced 50 lbs to 3400. · SRF3 adds HD Oil Cooler P/N G1148500 as alternative to standard cooler P/N G480503. · SRF3 brakes restructured: Hawk Blue 801993 pads, Wilwood 800065 rotors only; adds Girling 880358, Wilwood 880357, Tilton 880360 master cylinders. · AS Ford Mustang GT 5.0 2018- weight reduced from 3600 to 3525 lbs. · AS Ford Mustang GT 05-14 Restricted Prep Engine gains alternative gear ratios: 3.66, 2.43, 1.69, 1.32, 1.00, .65 · AS Ford Mustang GT 5.0L (15-17) flat plate restrictor reduced from 67mm to 64mm. · AS LS1/LS6 5.3L truck engine gains four approved intake part numbers: 12561269, 88894095, 89017363, 89017364. · AS Flotek Head plunge cut dimensions figure updated in GCR Section 9.1.6. · AS class notes cleanup: multiple Camaro, Firebird, CTS-V, Challenger, Mustang specs and fuel cell/ECM/head restrictions removed. · SRF drivers with disabilities may modify seat and controls for safety and comfort with approval and logbook notation. · SRF SADEV-SRF3 6-speed sequential transmission gear ratios wording clarified, effective 2025-04-01. · AS Spec Lines removes ECM flexibility restriction from five Cadillac and Chevrolet/Pontiac V8 models.show
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| Cal Club 2025 CALCL252025-02-22 | 2:02.354Gavin Sweeney · fastest of 5 · top 5 within 10.3s | 2:01.197Gavin Sweeney · fastest of 5 · top 5 within 9.6s | 103.5Gavin Sweeney | 1:50.233Caleb Shrader · fastest of 33 · top 5 within 0.4s | 1:50.825Caleb Shrader · fastest of 32 · top 5 within 0.8s | 118.2John Black | -10.372squal -12.121s | 91.4%qual 90.1% | 1:50.067Paul MacFarlane · only car | 1:48.522Paul MacFarlane · only car | 114.4Paul MacFarlane | -12.675squal -12.287s | 89.5%qual 90.0% | 1:56.445Roger Eagleton · fastest of 3 · top 3 within 4.0s | 1:55.849Roger Eagleton · fastest of 4 · top 4 within 5.3s | 108.7Roger Eagleton | -5.348squal -5.909s | 95.6%qual 95.2% | ||
132 earlier rule changes on record, in force before Cal Club 2025 (from 2019)17 tyres & wheels · 17 weight · 15 cars added · 10 suspension & brakes · 9 engine · 1 aero · 1 induction · 59 wording · 3 other · AS Ford Mustang Coyote engines increase restrictor to 80mm from 64mm or 67mm. · AS Mustang GT 05-14 4.6L loses 300 lbs; 15-17 and 2018+ models lose 61mm and 60mm restrictors respectively. · AS class gear ratio options specified for multiple American muscle cars, including Cadillac CTS-V, Chevrolet Camaro, Ford Mustang, Dodge Challenger, and Pontiac GTO. · AS LS-engine cars gain ECU freedom; Camaro/Firebird 93-02 LS1 removes fuel cell location restriction. · FC tire limit reduced to four dry and four wet for Regional/Major/Super Tour, eight for Runoffs. · FF and FC cars with sequential gearbox must add 10 lbs. to minimum weight, down from 25 lbs. · FV ferrous rotor no longer required to be smooth; may have up to three pad cleaning grooves per side. · SRF3 air filter rule removes K&N RC-9160 option, leaving only P/N WM301020 allowed. · SRF brake rotor minimum thickness increases from 12.20mm to 13.25mm, Wilwood vented rotor P/N 800065. · SRF3 Hoosier logo placement changes from four decals to three decals in different locations. · AS Ford Mustang GT models gain alternate transmission ratio options for 2024-09-01. · SRF Hoosier decal requirement reduced from four decals in specific locations to three decals with simpler placement rules. · SRF wet tires: P185/60R13 H20/W2 option removed; P185/65R13 W2 front now required with P205/60R13 W2 rear. · AS Ford Mustang GT 5.0L (2018-) classified at 3600 lbs with 60mm restrictor, Brembo BBK permitted. · SRF3 alternator pulley minimum weight reduced from 12 oz to 11 oz. · AS Chevrolet Camaro 1LE (2016-) classified with 3600 lbs minimum weight, 60mm restrictor, 275 tires. · AS Chevrolet/Pontiac Camaro & Firebird 82-92 5.7L LS1 classified at 3200 lbs with 65mm restrictor plate required. · AS Chevrolet Camaro, Firebird, and Ford Mustang models permitted to use Flo Tek cylinder heads. · AS Camaro/Firebird and GTO LS1 connecting rods approved: Callies CSC6100DS6A2AH, Scat 2-1CR6100-944, GM 12649190. · AS Cadillac CTS-V, Chevrolet Camaro SS, Dodge Challenger, Ford Mustang GT, Pontiac GTO allowed 11" wheels until 3/1/25. · FC adds F2000 Metrik ZF2 with Ford Zetec engine and four-piston Brembo calipers as spec-line car. · Chevrolet Camaro, Pontiac Firebird 70-81 Full Prep classified AS at 3400-3600 lbs with 250 lb weight reduction. · AS class: multiple cars gain fuel cell placement note allowing 24 inches from standard tank, unrestricted filler location. · Chevrolet Camaro 16- Full Prep classified into AS at 3400 lbs with 250 lb weight reduction. · AS adds Ford Mustang GT 05-14 Restricted prep Engine with 62mm FPR, 3400 lbs minimum, 18-inch wheels. · F600 Rotax 494, 493, 593 engines now require single expansion chamber and pull starter; electric starter optional. · SRF rain/brake light now requires Super Bright LEDs Inc. P/N PT-STRB-R24 with specific connector and rain light switch. · SRF requires Super Bright LEDs P/N PT-STRB-R24 rain/brake light with strobing capability and specific wiring. · SRF adds brake duct and pedal extension rules, rear shift cable clamp option, camber limit to 5.0°, radiator opening height 3.5" ±0.5", and P2 engine restrictor changes. · FV front wheel bearings wording clarified in GCR 9.1.1.C.10.G. · SRF radiator rule clarified: P/N 480466 replaceable with Automotive P/N 1R698, CU698 or manufacturer equivalent with documentation. · AS crate motor part number specified: GM Performance CT400 P/N 19370604 engine assembly for GM vehicles. · AS Spec Lines Ford Mustang GT 5.0L (15-17) max wheel size increases to 19.0 inches. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 now permits SPC-66045 alternate front upper control arms. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front brake caliper adapters for updated or backdated components. · FC tire marking rule clarified: four dry and wet tires for Regionals, eight each for Runoffs; damaged tire replacement procedures revised. · USF2000 Van Diemen with Mazda MZR LF-DE 2.0L added as spec line car in FC; removed from FX. · SRF Hoosier wet front tire updated to P/N 46100 P185/60R13 H20 or W2. · SRF Hoosier front rain tyre part number changes from 46100 to 46101 P185/65R13 W2. · SRF Renault Alliance solid front rotors banned; restrictor reduced 35mm to 34mm for 2011+ Kawasaki; minimum weight increased to 1100 lbs for 2009+ stock engines. · SRF3 tail sections allowed on SRFs with GEN3 airbox shimming up to 19 mm; alternate dash panel P/N 180100 or 180101 relocated in rules. · FC/FF PE3-8400 ECU monitor firmware version reduced from V3.04.50 to V3.04.35. · AS allows Hoosier W2 tyre option in addition to R7, R6, WET/H20. · AS Dodge Challenger 08-20 adds two transmission ratio options: 2.97, 2.10, 1.45, 1.00, 0.74, 0.50 or 2.26, 1.58, 1.19, 1.00, 0.77, 0.63. · AS Cadillac CTS-V 6.0L V8 removes 50 lbs weight penalty for 295 tire size. · FC Ford Zetec Performance Electronics ECU model renamed PE-3 to PE3-8400; Monitor firmware updated to V3.04.50. · SRF tire rule wording changed from 'Tires: must be run as delivered' to 'Tires must be run as delivered.' · SRF brake rotor minimum thickness reduced from 13.25 to 12.20mm; seal and air filter rules clarified. · FV connecting rod rules add Brian Crower part #BC6417 and Newland Group #4M113077 as allowed replacements. · FV connecting rods minimum weight 425.0 grams, center-to-center length 130 ± 0.10/-0.25 mm specified. · SMG long tube headers: Borla PN 17237 discontinued, Kooks PN 11312000 and American Racing PN MT3-05134300LSNC approved alternatives. · AS Mercury Capri (79-86) removed as individual spec line, merged into Ford Mustang (79-93) spec line. · AS Spec Mustang SMG loses 3.73 gear ratio and 355/300 mm brake specification. · AS Chevrolet, Pontiac, Ford full prep engines now permit alternate cylinder heads with restrictor plate ALL26180 and 1.250 inserts ALL26186 for regional competition. · FC chassis/frame section reorganized: anti-intrusion panels between main tubes clarified, suspension mounting restrictions strengthened, firewall requirements reworded. · FV connecting rod suppliers clarified: Crower SP93280B and BrianCrower BC6417 allowed as direct replacements. · FC Zetec ECU requirements clarified: Pectel T2 or Performance PE-3 required with specific communications ports and SCCA tune-file/map. · FV allows Crower SP93280B and Brian Crower Racing Rods as direct replacement connecting rods, must meet OEM minimum weight. · SRF front wet tire changes from P185/60R13 H20 to P185/65R13 W2; SRF3 adds mandatory G301048 restrictor plate Jan. 1, 2022. · FC composite anti-intrusion panels of non-uniform thickness limited to eight fasteners per side. · FC tire marking rules clarified: competitor responsible for declaring, marking, and logging tires with Tech before qualifying or race. · AS Chevrolet/Pontiac Camaro & Firebird 93-02 now allow BMR AA004 or UMI 2310 adjustable front upper control arms. · AS Pontiac GTO 04-06 LS1 to 3300 lbs, LS2 to 3350 lbs on 295 tire. · SRF wet tyres add Hoosier P185/60R13 W2 front and P205/60R13 W2 rear as alternatives to H20. · SRF adds SADEV-SRF3 6-speed sequential option with final drive 3.20 versus OEM 5-speed 3.85. · SRF seal procedures clarified: unsealed components need CSR inspection and logbook notation instead of engine removal. · AS Cadillac CTS-V 6.0L V8 removes 50 lbs tire size penalty, making it lighter. · AS consolidates seven SN95 Mustang spec lines into three: 94-04 including Cobra, 94-95 5.0/5.8, and 96-04 4.6L two/four valve. · AS Camaro/Firebird LT1/LS1 transmission code changes to 6362; Mustang GT 4.6L/5spd changes to 5.0L/6spd with 300 lbs weight reduction. · AS Camaro/Firebird and Mustang GT gear ratio specifications restored with alternate sets permitted. · AS Chevrolet Camaro & Firebird, Ford Mustang variants, Mercury Capri minimum weights increase 50 lbs across all model years. · SRF3 alternator pulley restricted to P/N G902130 or G902130A, 12oz minimum weight. · AS Mustang 4.6L/5spd loses 300 lbs; 5.0L/6spd gains 56mm restrictor requirement. · AS CTS-V LS6 and LS2 may now use Driveshaft Shop carbon fiber driveshaft for durability. · AS Chevrolet Camaro SS V8 6.2L model years extended from 10-13 to 10-15. · FC Pinto engine loses 10 lbs to 1190; Pinto aluminum head loses 10 lbs to 1190; Zetec loses 10 lbs to 1210. · SRF and SRF3 mandatory identification simplified: removed Ford Performance and Blue Oval decals, kept Hoosier logo placement. · Ford Mustang GT 5.0L 15-17 Restricted Preparation classified in AS with 55mm flat plate restrictor required. · AS underhood bracing on stock hoods, trunks, and rear decks may be modified or removed. · AS Cadillac CTS-V 04-07 with 295 tire drops to 3450 lbs; Camaro SS V8 10-13 275 tire removed; Challenger 08-20 gains 315 tire option at 3600 lbs. · AS Camaro & Firebird (93-02) and Mustang GT (05-14) specifications restored with 200 lb weight reduction for permitted heads. · AS Dodge Challenger 08-20 gains 6.1L and 6.4L V8 options; 5.7L weight rises to 3500 lbs on 295 tyres, 3600 on 315 tyres. · AS Camaro/Firebird (93-02) and Mustang Coupe GT (05-14) consolidated into single specs with 100 lb and 300 lb weight reductions respectively. · SRF shocks, springs, bump stops sealed; rear springs 412-429 lbs/in P/N 280390 only; previous parts no longer allowed. · FC: Pectel T2 and Performance PE-3 ECU maps clarified; SCCA Club or 2013 Pro map required. · AS Dodge Challenger 5.7L V8 gets iron block requirement, 10.5:1 compression max, intake valve 12.7 mm, exhaust 12.3 mm, intake duration 188°, exhaust duration 205°. · AS Dodge Challenger 08-14 rear spoiler part number changes from 1GL20RXF to 1GL20TZZAB. · FC Zetec engine minimum weight increases 20 lbs to 1220 lbs. · AS class pursues specified list of eligible tires; details of tire changes not provided in letter. · AS class pursuing specified list of eligible tires; details pending further communication. · No restrictor plate change implemented; 2021 AS Mustang Coyote under evaluation. · AS 2005-2009 Restricted Prep 4.6 3V now permits conversion to 2 valve configuration. · AS Ford Mustang Coupe GT 4.6L 3V Restricted Prep now permits Ford Performance camshaft kit P/N-M-6550-3V. · 2010-2014 Camaro reclassified to AS; full preparation classification approved effective 2020-07-01. · AS class cylinder head replacement options under review; implementation planned for 2021 season. · AS Mustang, Camaro, Firebird, Capri max brake rotor diameter increases from 12.2 to 13.1 inches. · AS rotor diameter increase approved; see Fastrack letter #28748 for details. · FV now allows 4 bolt wheels, previously restricted to 5 bolt wheels. · FV now supports 4-bolt pattern wheels in addition to existing wheel specifications. · SRF3 shock absorber brand restriction removed; all shocks must be sealed by Enterprises. · AS Chevrolet/Pontiac Camaro & Firebird (82-92) loses 50 lbs, to 3500. · SRF3 bump stop now must be SCCA P/N 280407 only, no modifications, optional, max one per shock. · SRF shock absorber bump stop clarified: only SCCA P/N 280407 allowed as delivered, maximum one per shock, effective 05/01/2020. · FV rain tire requirement changed to Hoosier #44266 22.5 x 5.0 x 15 WET or W3. · AS rear trailing arms may be replaced with tubular arms maintaining stock length and axle location purpose only. · AS Ford and GM full-prep cars get 200 lb weight reduction, up from 150 lb. · 05-10 Ford Mustang Coupe GT 4.6L OHC classified AS with 3200 lbs minimum weight, HR cam restricted prep. · AS 10-15 Chevrolet Camaro Full Prep classified with 3400 lbs base weight, over 313 CID engine 3700 lbs maximum. · FV allows non-spec Hoosier tires in Regional races until 2020-01-01, when spec tires become required. · FV allows rear tires on front of car; mandates Hoosier #43337 fronts and #43353 rears, plus #44266 rain tire from 2020-01-01. · SRF rain and brake rule wording updated; supersedes GCR 9.3.32.B.2 effective 1/1/202 through 12/31/2024. · FC Zetec connecting rods now allow Eagle #CRS5483F3D in addition to original Ford. · FC adds Mahle #930169439 piston as alternate option to existing Ford, Sealed Power, and United Engine choices. · FV wheels clarified: 15" x 4J standard or 15" x 4.5J steel VW, 5-bolt pattern, same track dimensions. · SRF bans tire warmers and cooling methods other than natural air convection or conduction. · SRF front nose weight minimum reduced from 35 to 32 lbs. · SRF3 reclassified as Spec Racer Ford 3 with 1.6L conversion; SRF2 becomes Regional Only Class. · AS Spec Mustang (SMG) added as Restricted Prep class. · FV exhaust outlet location tightened to 1–4 inches behind rearmost body part. · FV wheels now permit 15-inch 4.5J steel wheels within C.2 track dimensions, adding to standard 4J options. · AS class minimum ride height clarified to 5 inches measured at rocker panel, excluding seams and cladding. · SRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102. · AS Ford Mustang (79-93) 313 CID and under loses 100 lbs to 3150; over 313 CID loses 100 lbs to 3450. · FV exhaust opening can now extend to 4 inches behind body rear, previously 3 inches maximum. · SRF3 nose assembly must use approved multi-piece design; no modifications allowed except as specified. · FC Wiseco piston and Crower connecting rod part numbers updated; minimum weight 976 grams. · FV front track maximum 52.500" and rear track 49.125"-50.750" no longer prohibits spacers. · SRF3 brakes now allow Hawk Blue 9012 pads P/N 801993 only; shocks simplified to Penske P/N 280396 sealed assembly only, with optional SCCA Enterprises bump rubber P/N 280407 from 05/01/2020. · FV disc brake assembly minimum weight clarified to 16.5 lbs total; caliper minimum weight requirement removed. · AS Spec Mustang (SMG) newly classified with 107.1 wheelbase, 3.73 gears, 355mm front brakes, 300mm rear. · FV intake manifold horizontal tube measurement locations clarified between 1.500" and 8.000" on short side. · FC Wiseco piston and Crower connecting rod assembly minimum weight increases from 555 to 976 grams.show
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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 FV" is the class's best as a share of FV'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 FV'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.