BoP Lab / Buttonwillow Raceway Park
FC vs FV vs EP pace at Buttonwillow Raceway Park
Quickest here: FC 1:45.137 Robert Armington, Cal Club 2026 qualifying · FV 1:58.898 Mace Gjerman, Cal Club 2026 race · EP 1:53.088 Glen McCready, Cal Club 2025 qualifying
| Event | FC | FV | EP | ||||||||||||
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| Qual best | Race best | Trap | Qual best | Race best | Trap | vs FC | % of FC | Qual best | Race best | Trap | vs FC | % of FC | |||
| Cal Club 2026 CALCL262026-02-21 | 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%) | 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%) | +13.584squal +17.425s | 112.9%qual 116.6% | 1:57.474Kurt Frietzsche · fastest of 4 · top 4 within 4.5s+4.386s (+3.88%) | 1:57.999Kurt Frietzsche · fastest of 4 · top 4 within 4.9s+4.512s (+3.98%) | 131.6Joe Carr+23.8 mph (+22.1%) | +12.685squal +12.337s | 112.0%qual 111.7% | ||
25 rule changes (FC: 2, EP: 23)9 weight · 3 induction · 2 engine · 1 cars added · 10 wording · EP BMW 325i/is E30 throttle body specified as 60mm in fuel injection notes. · 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. · EP Triumph TR2-TR4A allows 5-speed gearbox without overdrive; removes Weber carb and weight specification. · EP BMW Z3 2.5L restrictor reduced 52mm to 50mm, weight increased to 2550 lbs base; five other BMW models get smaller restrictors. · EP Nissan 280Z minimum weight reduced from 2560 to 2400 lbs. · EP Mazda MX-5 1.8L 90-97 weight reduced to 2125 lbs from 2150 lbs. · HP Austin-Healey Sprite/Midget 1098cc minimum weight drops 80 lbs to 1550. · HP Volvo 142/142E gains compression ratio limit 12.0:1 and valve lift limit .425". · HP Mini Cooper 07-15 valve lift reduced to .390", from .450". · FP and HP Volkswagen Rabbit descriptions updated: Convertible changed to Cabriolet in FP; Cabriolet added to three HP engine variants. · EP, FP, HP: rear drum brake to disc conversion clarified; rotors solid, diameter limited to largest front rotor permitted. · EP Ford Mustang (94-98) fuel injected throttle body inside diameter specified at 60. · HP Plymouth Arrow transmission max speeds clarified to 4 or 5. · EP, FP, HP wheel diameter added to Appendix G as absolute maximum specification. · EP, FP, HP throttle body inside dimensions must remain stock with +/-.25mm tolerance; butterfly dimensions stock in FP, HP only. · EP BMW Z4 03-05 restricted to 52mm flat plate intake restrictor. · EP Fiat 124 Spider 1600 & 2000 weight drops 50 lbs to 2000; carburetors gain 2mm chokes to 36mm. · HP Fiat X-1/9 base weights reduced 50–53 lbs across 1300 and 1500 spec lines. · Chevrolet Spark 16-22 classified HP Pre at 1850 lbs minimum weight, fuel injected, 1399 cc. · HP Ford Festiva 88-93 minimum weight drops to 1600 lbs, variants to 1640 and 1680 lbs; compression ratio raised to 11.0:1. · EP BMW Z3 and 3-series models get smaller intake restrictors: Z3 2.5L to 52mm, Z3 2.8L to 55mm, 328i to 58mm, 325i to 56mm. · EP, FP, HP: interior or exterior mirrors meeting rule 9.3.36 now permitted. · EP Honda S2000 1997cc base loses 75 lbs to 2375; 2157cc base loses 60 lbs to 2450. · EP Mazda MX-5/Miata 99-05 minimum weight drops to 2100 lbs, 2153 lbs with power adder, 2205 lbs with two adders.show
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| Cal Club 2025 CALCL252025-02-22 | 1:50.067Paul MacFarlane · only car | 1:48.522Paul MacFarlane · only car | 114.4Paul MacFarlane | 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 | +12.675squal +12.287s | 111.7%qual 111.2% | 1:53.088Glen McCready · fastest of 5 · top 5 within 10.6s | 1:53.487Glen McCready · fastest of 5 · top 5 within 10.6s | 107.8Joe Carr | +4.965squal +3.021s | 104.6%qual 102.7% | ||
128 earlier rule changes on record, in force before Cal Club 2025 (from 2019)22 weight · 16 cars added · 11 induction · 8 tyres & wheels · 7 engine · 4 suspension & brakes · 2 aero · 57 wording · 1 other · EP BMW Z3 2.5L requires 52mm flat plate intake restrictor; Z3 2.8L 55mm; 328i/is E36 58mm; 328i/ci E46 58mm; 325i/is E46 56mm; 325i/is E36 56mm; 325is M-Technic 56mm. · EP BMW 325i/is E30 (84-91) weight reduced 50–52 lbs across three spec lines to 2150, 2204, 2258. · EP Triumph GT6 switches to three Weber 40 DCOE carbs with 28mm chokes, weight rises 50 lbs to 1990. · HP Sprite and Midget 1275cc and 1098cc Level 2 compression ratio raised to 12.0:1. · EP Mazda Miata front and rear track widths increased to 1516/1534 mm (59.7/60.4 in.) across all generations. · 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. · HP Volkswagen Golf and Jetta 85-92 track correction: front 1537mm (60.5in), rear 1529mm (60.2in). · Nissan 300ZX 84-89 classified to EP at 2550 lbs minimum, 2960cc 6-cyl SOHC, fuel injection, 12.0:1 compression limit, 0.500" valve lift limit. · Mazda RX-7 92-97 newly classified EP Prep Level 2 at 2200–2310 lbs with 13B 6-port rotary engine. · EP Mazda RX-8 (04-11) alternate spec line removed; one primary line remains. · FC adds F2000 Metrik ZF2 with Ford Zetec engine and four-piston Brembo calipers as spec-line car. · HP removes four redundant VW spec lines: Rabbit Cabriolet 1780, Scirocco 1588, Scirocco 1780 8-valve, Scirocco 1588. · HP Honda Civic 1.5 (88-91) weight reduced to 2175 lbs base, 2229 lbs with power adder, 2284 lbs with two. · EP BMW Z3 2.5L weight increases to 2500 lbs, 2563 lbs with turbo, 2625 lbs with supercharger. · EP Mazda MX-5 1.8L 1990-97 minimum weight drops to 2150 lbs; 1994-97 variants to 2000, 2050, 2100 lbs respectively. · EP Triumph GT6 dual 1.75" carbs weight drops to 1940 lbs; triple Weber 40 DCOE options consolidated. · EP Honda S2000 fuel injected throttle body inside diameter increases from 62mm to 64mm. · EP Triumph TR8 dry sump allowance moved from carburetor line to notes section. · EP Porsche 944/924S 2.5L and 2.7L weight minimums corrected: 2479cc to 2306/2363 lbs, 2681cc to 2358/2415 lbs. · F600 Rotax 494, 493, 593 engines now require single expansion chamber and pull starter; electric starter optional. · EP Porsche 944/924S combines 2.5L and 2.7L variants with new weights: 2250–2415 lbs depending on engine and year. · EP Triumph GT6 minimum weight reduced to 1800 lbs. · FV front wheel bearings wording clarified in GCR 9.1.1.C.10.G. · EP Triumph TR8 78-81 removes alternate front hub allowance note; stock hubs now required. · EP Triumph GT6 carburetors change from SU or Stromberg to 1.5" Auto-type. · EP Triumph GT6 brakes may now use TR-6 standard or alternate calipers and discs. · FP and HP Sprite, Midget, and Spitfire 1500 intake valve size corrected to 36.6/(1.44). · FC tire marking rule clarified: four dry and wet tires for Regionals, eight each for Runoffs; damaged tire replacement procedures revised. · EP Porsche 914-6 2.0L intake valves increase to 2.0 mm, exhaust valves corrected to 38.0 mm. · USF2000 Van Diemen with Mazda MZR LF-DE 2.0L added as spec line car in FC; removed from FX. · EP BMW Z3 2.5L intake restrictor reduced from 58mm to 56mm flat plate. · EP 79-85 RX-7 12A/13B brake spec simplification removes hub/rotor weight minimum allowance. · EP 280Z carburetor option adds Hitachi-SU 1bbl 46mm throttle bores alongside fuel injection. · EP Mazda RX-2, RX-3, RX-4, and 12A RX-7 now allow 2 bbl fuel injected throttle body w/ 42mm chokes on dual-y manifold. · EP Mazda RX-2, RX-3, RX-3SP, and RX-4 minimum weights reduced 50–52 lbs across all spec lines. · EP Triumph TR8 78-81 now allowed to run dry sump. · EP, FP, HP cylinder head ports limited to 1 inch maximum depth matching from mating surface. · EP Prep 280ZX (79-83) added to spec lines with 2425–2546 lbs, 2760cc SOHC 6-cyl, fuel injection, 12.0:1 compression limit, .500" valve lift limit. · FC/FF PE3-8400 ECU monitor firmware version reduced from V3.04.50 to V3.04.35. · VW New Beetle 2.5L 5-cyl added to EP at 2400–2520 lbs, 2480 cc, fuel injection, comp ratio 12.0:1 max, valve lift 0.500" max. · EP Mazda RX-7 12A/13B gains fuel injection option on dual-y manifold with 42mm choke(s). · EP VW Corrado 92-95 stroke corrected to 90.3 mm, displacement to 2792 cc. · FC Ford Zetec Performance Electronics ECU model renamed PE-3 to PE3-8400; Monitor firmware updated to V3.04.50. · EP Subaru BRZ and Toyota 86/Scion FR-S model year ranges updated to 13-20. · EP Mazda MX-5 Global Cup 16-22 minimum weight set to 2400 lbs; sequential gearbox allowed with +150 lbs penalty. · BMW 128i (08-13) classified in EP at 2700 lbs minimum with stock throttle body, 11.0:1 compression ratio, 0.400 in. valve lift limits. · EP/FP/HP open cars may now use carbon fiber hardtops if they retain OEM appearance in all exterior profiles. · EP Mazda RX-8 13B carburetor rules clarified: dual 2bbl carb, fuel injected throttle body, or stock fuel injection permitted. · EP and FP Production clarifies idle control valve rules: stock devices allowed original, removed with blocked ports, or mechanical replaced with electronic stock type. · EP BMW Z3 2.5L intake restrictor reduced from 59mm to 58mm flat plate. · Ford Mustang 99-03 classified to EP at 2700/2768/2835 lbs; 94-98 Mustang weight reduced to 2550/2614/2678 lbs. · EP, FP, HP Improved Touring cars may use any DOT-approved tire per section 9.3.45 in Production class. · 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. · EP, FP, HP classes allow stock/original idle control devices unmodified or completely removed with openings blocked. · EP Porsche 968 (92-95) now allows dry sump. · EP 1979-1985 Mazda RX-7 12A and 13B weight reduced by 50-53 lbs across all configurations. · EP Porsche 968 intake valve size increased from 37 to 39.0 mm. · EP, FP, HP front-wheel-drive cars may alter body and suspension to install alternate transmission, transaxle, and axle shaft. · EP BMW Z3 2.5L allows alternate throttle body from 92-95 325i with Turner adapter; head casting 1738400 permitted with specific blocks. · 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. · EP Porsche 944S2 89-91 requires 56mm flat plate intake restrictor; comp ratio max 12.0:1, valve lift max 0.500". · HP Corolla GTS RWD (84-87) added at 2300 lbs; HP Corolla FX16 FWD (87-88) added at 2260 lbs; old Corolla (84-87) removed. · 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. · 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. · HP Toyota MR-2 1.6L (85-89) track corrected to 15.47 inches front and rear. · Honda S2000 (00-03) reclassified as EP Prep with F22c engine option: 1997cc or 2157cc, weight 2450–2636 lbs depending on displacement. · EP Nissan 240-SX S13/S14 loses 200-210 lbs minimum weight; comp ratio rises to 12.0:1, valve lift to .500. · EP Lotus/Caterham 7 America carburetor changed from IT fuel injection prep to fuel injection. · Daimler SP 250 classified in EP at 2165 lbs with 2548 cc OHV 8-cylinder engine. · EP, FP, HP clarifies percentage weight penalties sum first, then apply to base weight, rounding to nearest pound. · 84-87 Mazda 626 reclassified from FP to HP with 2300–2415 lbs weight, 1998cc SOHC, dual 32mm carbs. · FP Fiat X1/9 brake rotors change to 257 (10.1) x 12 (.407) solid disc. · EP Mazda MX-5 year range corrected from 06-14 to 06-15. · Mazda 3 S 04-08 classified in EP at 2350 lbs minimum, 2.26L DOHC, 12.0:1 compression, .500" valve lift limit. · FC Pinto engine loses 10 lbs to 1190; Pinto aluminum head loses 10 lbs to 1190; Zetec loses 10 lbs to 1210. · EP Austin-Healey 3000 Mk. I, II, III now allows TR-6 front calipers and discs as alternate. · FP Volkswagen Golf and Jetta 1.8 lose 50 lbs each, to 1900. HP Jetta GLI engine code removed. · EP, FP, HP Level 1 and Level 2 induction systems: clarified carburetor and fuel injection rules, jets/needles/rods unrestricted in Level 2. · EP Datsun SRL 311U Roadster minimum weight reduced to 1925 lbs from 2000 lbs. · EP Triumph TR8 78-81 weight reduced from 2600 to 2500 lbs. · HP 84-87 Toyota Corolla wheel diameter increases from 13 to 15 inches. · FC: Pectel T2 and Performance PE-3 ECU maps clarified; SCCA Club or 2013 Pro map required. · EP BMW Z3 2.5L iron block casting 1738566-C designation removed, wording clarification only. · FC Zetec engine minimum weight increases 20 lbs to 1220 lbs. · Porsche 911 S 67-68 classified in EP at three weight levels: 1800, 1845, or 1890 lbs. · 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. · EP BMW 2.8L, 328i E36/E46, and 325i E36 blocks now iron only; 325i E46 aluminum only. · 1990-1994 Mazda Protege classified in FP Pre at 2150–2258 lbs with 1839cc DOHC engine, fuel injection. · HP Mini Cooper model year ranges for convertibles revised: 02-06 now includes 05-08, 07-13 now includes 09-15. · EP Caterham 7 Spec Line removes redundant suspension note, clarifies engine prep limits and comp ratio to 10.0:1. · EP BMW Z3 2.5L compression ratio capped 12.0:1, valve lift .500, 59mm restrictor required; Z3 2.8L same limits added; 944S2 compression 12.0:1, valve lift .500, 56mm restrictor required. · EP BMW 325is M-Technic loses 100–105 lbs across three weight configurations, to 2550–2678. · HP Datsun 510 gains 40 DCOE carburetor option alongside existing 40 DCN and 36mm DCNVH choices. · EP BMW fuel injected throttle body maximum inside diameter set to 64mm. · FV rain tire requirement changed to Hoosier #44266 22.5 x 5.0 x 15 WET or W3. · HP Datsun 1200 carburetor choke size increases from 26mm to 30mm. · FP and EP Mazda Miata models standardized to 55mm throttle body diameter; brake spec clarified. · 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. · EP, FP, HP cylinder head rules reorganized for clarity; no performance change. · 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. · FV exhaust outlet location tightened to 1–4 inches behind rearmost body part. · FP and HP Austin-Healey Sprite Mk I and MG Midget variants may replace rear bodywork aft of cockpit with stock-appearing alternate material components. · EP Mazda MX-5 Global Cup classification year changes from 16-18 to 16-19. · Production suspension rule clarifies spindles, hubs, bushings, bearings, ball joints unrestricted. · Production carb rules clarified: carburetor options, fuel injection throttle body dimensions, and intake manifold restrictions reorganised and refined. · EP, FP, HP carburetors clarified: jets, needles, metering rods, needle valves unrestricted; choke parts removable; permitted optional carburetors listed. · FV wheels now permit 15-inch 4.5J steel wheels within C.2 track dimensions, adding to standard 4J options. · EP Mazda MX-5/Miata eligibility years expanded from 1999-2002 to 1999-2005. · FV exhaust opening can now extend to 4 inches behind body rear, previously 3 inches maximum. · EP Mazda RX-8 firewall modification allowed for 13B engine fitment in stock location. · 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. · EP, FP, HP clarified: tapered holes in ball joints now allowed for bolt conversion; wheel bearings and hubs unrestricted at any wheel. · EP open cars may now use aftermarket hardtops if they retain OEM appearance; specific model hardtop allowances removed. · FV disc brake assembly minimum weight clarified to 16.5 lbs total; caliper minimum weight requirement removed. · EP Mazda RX-7 12A and 13B (79-85) lose up to 80 lbs; 13B (86-91) loses up to 79 lbs. · 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 FC" is the class's best as a share of FC'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 FC'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.