BoP Labbeta

BoP Lab / Buttonwillow Raceway Park

EP vs FV pace at Buttonwillow Raceway Park

Class · click a class to switch, + to compare alongside (up to 4)
Reference class · the others' laps as a share of this one's at the same event, so years compare despite weather; + a class above to measure against it
Track configuration

Quickest here: EP 1:53.088 Glen McCready, Cal Club 2025 qualifying · FV 1:58.898 Mace Gjerman, Cal Club 2026 race

1:521:541:561:582:002:0223 rule changes between Cal Club 2025 and Cal Club 202623 ▾EP race best at Cal Club 2025: 1:53.487 (Glen McCready)EP race best at Cal Club 2026: 1:57.999 (Kurt Frietzsche)EP qualifying best at Cal Club 2025: 1:53.088 (Glen McCready)EP qualifying best at Cal Club 2026: 1:57.474 (Kurt Frietzsche)FV race best at Cal Club 2025: 2:01.197 (Gavin Sweeney)FV race best at Cal Club 2026: 1:58.898 (Mace Gjerman)FV qualifying best at Cal Club 2025: 2:02.354 (Gavin Sweeney)FV qualifying best at Cal Club 2026: 2:02.562 (Gavin Sweeney)Cal Club 20252025Cal Club 20262026
EPFVsolid race · dashed qualifying · slower is lower
100%102%104%106%108%23 rule changes between Cal Club 2025 and Cal Club 202623 ▾EP race best at Cal Club 2025: 100.0% of EP's (Glen McCready)EP race best at Cal Club 2026: 100.0% of EP's (Kurt Frietzsche)EP qualifying best at Cal Club 2025: 100.0% of EP's (Glen McCready)EP qualifying best at Cal Club 2026: 100.0% of EP's (Kurt Frietzsche)FV race best at Cal Club 2025: 106.8% of EP's (Gavin Sweeney)FV race best at Cal Club 2026: 100.8% of EP's (Mace Gjerman)FV qualifying best at Cal Club 2025: 108.2% of EP's (Gavin Sweeney)FV qualifying best at Cal Club 2026: 104.3% of EP's (Gavin Sweeney)Cal Club 20252025Cal Club 20262026
EPFVsolid race · dashed qualifying · each class's best lap as a share of EP's at the same event (the reference class, changeable above); 100% is level, higher is quicker
EventEPFV
Qual bestRace bestTrapQual bestRace bestTrapvs EP% of EP
Cal Club 2026 CALCL262026-02-211:57.474Kurt 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%)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%)+0.899squal +5.088s100.8%qual 104.3%
23 rule changes (EP: 23)8 weight · 3 induction · 2 engine · 1 cars added · 9 wording · EP BMW 325i/is E30 throttle body specified as 60mm in fuel injection notes. · 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.showhide
  • EP Request to Update E30 BMW Throttle Body Diameter Verbiage #39363wordingneutralEP BMW 325i/is E30 throttle body specified as 60mm in fuel injection notes.
  • EP TR2 Notes E&O #39180wordingunclearEP Triumph TR2-TR4A allows 5-speed gearbox without overdrive; removes Weber carb and weight specification.
  • EP Balance of Power #39187induction +50 lbsslowerEP BMW Z3 2.5L restrictor reduced 52mm to 50mm, weight increased to 2550 lbs base; five other BMW models get smaller restrictors.
  • EP Please Lower Weight of 280Z #38871weight -160 lbsfasterEP Nissan 280Z minimum weight reduced from 2560 to 2400 lbs.
  • EP Miata Weight Adjustment Follow Up #38949weight -25 lbsfasterEP Mazda MX-5 1.8L 90-97 weight reduced to 2125 lbs from 2150 lbs.
  • EP Weight Break for 1098 Midget / Sprite #38970weight -80 lbsfasterHP Austin-Healey Sprite/Midget 1098cc minimum weight drops 80 lbs to 1550.
  • EP HP Volvo 142 spec omission #38994engineslowerHP Volvo 142/142E gains compression ratio limit 12.0:1 and valve lift limit .425".
  • EP HP Mini DOHC 1.6 #38996engineslowerHP Mini Cooper 07-15 valve lift reduced to .390", from .450".
  • EP Add to Rabbit description #39019wordingneutralFP and HP Volkswagen Rabbit descriptions updated: Convertible changed to Cabriolet in FP; Cabriolet added to three HP engine variants.
  • EP Clean-up 9.1.5.E.7e #39025wordingneutralEP, FP, HP: rear drum brake to disc conversion clarified; rotors solid, diameter limited to largest front rotor permitted.
  • EP Add TB size to Ford Mustang (94-98) Spec Line #39130wordingneutralEP Ford Mustang (94-98) fuel injected throttle body inside diameter specified at 60.
  • EP HP Plymouth Arrow spec omission #38995wordingneutralHP Plymouth Arrow transmission max speeds clarified to 4 or 5.
  • EP Add Wheel Diameter to Appendix G #39008wordingneutralEP, FP, HP wheel diameter added to Appendix G as absolute maximum specification.
  • EP Add TB ID tolerance to general Prod rules #39009wordingneutralEP, FP, HP throttle body inside dimensions must remain stock with +/-.25mm tolerance; butterfly dimensions stock in FP, HP only.
  • EP BMW Z4 update #38490inductionslowerEP BMW Z4 03-05 restricted to 52mm flat plate intake restrictor.
  • EP EP Fiat 124 Spider Competition Adjustment Request #38498weight -50 lbsfasterEP Fiat 124 Spider 1600 & 2000 weight drops 50 lbs to 2000; carburetors gain 2mm chokes to 36mm.
  • EP Base Weight Adjustment for H-Production X1/9 Spec Lines #38255weight -50 lbsfasterHP Fiat X-1/9 base weights reduced 50–53 lbs across 1300 and 1500 spec lines.
  • EP Request for Classification of Chevrolet Spark #37755cars addedneutralChevrolet Spark 16-22 classified HP Pre at 1850 lbs minimum weight, fuel injected, 1399 cc.
  • EP Request to Lower Ford Festiva Minimum Weight to 1600 LBS #37939weight -100 lbsfasterHP Ford Festiva 88-93 minimum weight drops to 1600 lbs, variants to 1640 and 1680 lbs; compression ratio raised to 11.0:1.
  • EP Request Competition Adjustment to BMW Z3 2.5L #37120inductionslowerEP 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 Interpretation of Production Rules on Mirrors #37235wordingneutralEP, FP, HP: interior or exterior mirrors meeting rule 9.3.36 now permitted.
  • EP Weight Reduction for Honda S2000 #37466weightfasterEP Honda S2000 1997cc base loses 75 lbs to 2375; 2157cc base loses 60 lbs to 2450.
  • EP Mazda 1999 Miata 1.8L #37488weight -50 lbsfasterEP Mazda MX-5/Miata 99-05 minimum weight drops to 2100 lbs, 2153 lbs with power adder, 2205 lbs with two adders.
Cal Club 2025 CALCL252025-02-221:53.088Glen McCready · fastest of 5 · top 5 within 10.6s1:53.487Glen McCready · fastest of 5 · top 5 within 10.6s107.8Joe Carr2:02.354Gavin Sweeney · fastest of 5 · top 5 within 10.3s2:01.197Gavin Sweeney · fastest of 5 · top 5 within 9.6s103.5Gavin Sweeney+7.710squal +9.266s106.8%qual 108.2%
109 earlier rule changes on record, in force before Cal Club 2025 (from 2019)18 weight · 14 cars added · 11 induction · 7 tyres & wheels · 6 engine · 4 suspension & brakes · 2 aero · 46 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. · 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. · 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. · 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). · EP Porsche 914-6 2.0L intake valves increase to 2.0 mm, exhaust valves corrected to 38.0 mm. · 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. · 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. · 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. · 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. · FV allows Crower SP93280B and Brian Crower Racing Rods as direct replacement connecting rods, must meet OEM minimum weight. · 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. · 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. · EP BMW Z3 2.5L iron block casting 1738566-C designation removed, wording clarification only. · 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. · 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. · 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.showhide
  • EP Effective date for Jan 2025 GCR updates #37654inductionslowerEP 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 Request to Reduce Weight of BMW 325i/is E30 (84-91) Spec Line #37119weight -50 lbsfasterEP BMW 325i/is E30 (84-91) weight reduced 50–52 lbs across three spec lines to 2150, 2204, 2258.
  • EP Triumph GT6 Adjustments #37112inductionslowerEP Triumph GT6 switches to three Weber 40 DCOE carbs with 28mm chokes, weight rises 50 lbs to 1990.
  • EP 1275 HP Spridget Level 2 Only #36518enginefasterHP Sprite and Midget 1275cc and 1098cc Level 2 compression ratio raised to 12.0:1.
  • EP NA Miata Track Width Correction #36902wordingneutralEP Mazda Miata front and rear track widths increased to 1516/1534 mm (59.7/60.4 in.) across all generations.
  • FV Disc Brakes #36822suspension & brakesneutralFV ferrous rotor no longer required to be smooth; may have up to three pad cleaning grooves per side.
  • EP Errant entry in HP production line item #36231wordingneutralHP Volkswagen Golf and Jetta 85-92 track correction: front 1537mm (60.5in), rear 1529mm (60.2in).
  • EP NIssan 300ZX Z31 to EP #35830cars addedneutralNissan 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.
  • EP RX7 1993 and Up Request In EP Spec Lines, classify #36031cars addedneutralMazda RX-7 92-97 newly classified EP Prep Level 2 at 2200–2310 lbs with 13B 6-port rotary engine.
  • EP Clean-up Multiple EP RX-8 Spec Lines In EP #36156wordingneutralEP Mazda RX-8 (04-11) alternate spec line removed; one primary line remains.
  • EP GCR Correction - Redundant HP Spec Lines #35623wordingneutralHP removes four redundant VW spec lines: Rabbit Cabriolet 1780, Scirocco 1588, Scirocco 1780 8-valve, Scirocco 1588.
  • EP Update 1988-1991 Civic to Match 1988-1991 CRX #35399weightfasterHP Honda Civic 1.5 (88-91) weight reduced to 2175 lbs base, 2229 lbs with power adder, 2284 lbs with two.
  • EP Request to Review Z3 2.5 Spec Line #35073weight +50 lbsslowerEP BMW Z3 2.5L weight increases to 2500 lbs, 2563 lbs with turbo, 2625 lbs with supercharger.
  • EP Miata Alternate Head #35253weight -50 lbsfasterEP 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 Adjustments #35255weightfasterEP Triumph GT6 dual 1.75" carbs weight drops to 1940 lbs; triple Weber 40 DCOE options consolidated.
  • EP Honda S2000 throttle body #35272inductionfasterEP Honda S2000 fuel injected throttle body inside diameter increases from 62mm to 64mm.
  • EP Correction within Triumph TR8 Spec Line #35315wordingneutralEP Triumph TR8 dry sump allowance moved from carburetor line to notes section.
  • EP Correction to EP 924S/944 Spec Line #35317wordingneutralEP Porsche 944/924S 2.5L and 2.7L weight minimums corrected: 2479cc to 2306/2363 lbs, 2681cc to 2358/2415 lbs.
  • EP Porsche 944/924S Rule Change Request #35002cars addedneutralEP Porsche 944/924S combines 2.5L and 2.7L variants with new weights: 2250–2415 lbs depending on engine and year.
  • EP Triumph GT6 Adjustments #35054weight -30 lbsfasterEP Triumph GT6 minimum weight reduced to 1800 lbs.
  • FV FV Wheel Bearing Clarification #35150wordingneutralFV front wheel bearings wording clarified in GCR 9.1.1.C.10.G.
  • EP Hub Note Clean Up In EP TR8 Spec Line #34649wordingneutralEP Triumph TR8 78-81 removes alternate front hub allowance note; stock hubs now required.
  • EP Triumph GT6 Adjustments #34662wordingunclearEP Triumph GT6 carburetors change from SU or Stromberg to 1.5" Auto-type.
  • EP Triumph GT6 Adjustments: Brakes #34663wordingneutralEP Triumph GT6 brakes may now use TR-6 standard or alternate calipers and discs.
  • EP Correct Intake Valve Size on 1500cc Midget/Spitfire #34419wordingneutralFP and HP Sprite, Midget, and Spitfire 1500 intake valve size corrected to 36.6/(1.44).
  • EP 914-6 Valve Size Correction #34185enginefasterEP Porsche 914-6 2.0L intake valves increase to 2.0 mm, exhaust valves corrected to 38.0 mm.
  • EP Investigate Parity of Z3 #33343inductionslowerEP BMW Z3 2.5L intake restrictor reduced from 58mm to 56mm flat plate.
  • EP Revise 79-85 RX7 Brake Spec Line Allowance #33293wordingunclearEP 79-85 RX-7 12A/13B brake spec simplification removes hub/rotor weight minimum allowance.
  • EP Request alternate carburetors for EP 280z #33405wordingneutralEP 280Z carburetor option adds Hitachi-SU 1bbl 46mm throttle bores alongside fuel injection.
  • EP Fuel Injection 12a Mazda RX3 #33434inductionneutralEP 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 RX3 - Weight Reduction #33436weight -50 lbsfasterEP Mazda RX-2, RX-3, RX-3SP, and RX-4 minimum weights reduced 50–52 lbs across all spec lines.
  • EP Request TR8 Dry Sump Allowance #33460enginefasterEP Triumph TR8 78-81 now allowed to run dry sump.
  • EP Review Limited Prep Port Matching Rules #33600wordingneutralEP, FP, HP cylinder head ports limited to 1 inch maximum depth matching from mating surface.
  • EP 280ZX Classification Request #33611cars addedneutralEP 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.
  • EP Request to classify VW New Beetle 2.5L in EP #32725cars addedneutralVW 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 Request Rotary Injection on Dual Y manifold #32775inductionunclearEP Mazda RX-7 12A/13B gains fuel injection option on dual-y manifold with 42mm choke(s).
  • EP Request for Corrado Stroke & Displacement Correction #32985wordingneutralEP VW Corrado 92-95 stroke corrected to 90.3 mm, displacement to 2792 cc.
  • EP Subaru BRZ Model Years #32500wordingneutralEP Subaru BRZ and Toyota 86/Scion FR-S model year ranges updated to 13-20.
  • EP EP MX-5 Global Cup Car #32218weightslowerEP Mazda MX-5 Global Cup 16-22 minimum weight set to 2400 lbs; sequential gearbox allowed with +150 lbs penalty.
  • EP Please Class BMW 128i in EP #32370cars addedneutralBMW 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 Inconsistency in Body Work Descriptions #32396aerofasterEP/FP/HP open cars may now use carbon fiber hardtops if they retain OEM appearance in all exterior profiles.
  • EP Mazda RX8 with 13b Rotary #32170wordingneutralEP Mazda RX-8 13B carburetor rules clarified: dual 2bbl carb, fuel injected throttle body, or stock fuel injection permitted.
  • EP Request Idle control valve clarification #32178wordingneutralEP and FP Production clarifies idle control valve rules: stock devices allowed original, removed with blocked ports, or mechanical replaced with electronic stock type.
  • EP EP Adjustments #31858inductionslowerEP BMW Z3 2.5L intake restrictor reduced from 59mm to 58mm flat plate.
  • EP 1999 3.8L Ford Mustang to EP? #31635weightfasterFord Mustang 99-03 classified to EP at 2700/2768/2835 lbs; 94-98 Mustang weight reduced to 2550/2614/2678 lbs.
  • EP Improved Touring Tires #32064tyres & wheelsneutralEP, FP, HP Improved Touring cars may use any DOT-approved tire per section 9.3.45 in Production class.
  • FV Connecting Rod Update Request for 9.1.1.C Formula Vee (FV) 5.C.6 #32160wordingneutralFV connecting rod rules add Brian Crower part #BC6417 and Newland Group #4M113077 as allowed replacements.
  • FV E&O clarification of connecting rod center-to-center length #32183wordingneutralFV connecting rods minimum weight 425.0 grams, center-to-center length 130 ± 0.10/-0.25 mm specified.
  • EP Throttle Body and Idle Air #31800wordingneutralEP, FP, HP classes allow stock/original idle control devices unmodified or completely removed with openings blocked.
  • EP Porsche 968 Engine Questions #31831otherneutralEP Porsche 968 (92-95) now allows dry sump.
  • EP Request weight reduction for 1979-1985 Mazda RX-7 #31833weightfasterEP 1979-1985 Mazda RX-7 12A and 13B weight reduced by 50-53 lbs across all configurations.
  • EP Porsche 968 Engine Questions #31478enginefasterEP Porsche 968 intake valve size increased from 37 to 39.0 mm.
  • EP PCS E. 2. n. 4. Add Axle Shaft to Allow FWD the Same Freedom #31592wordingneutralEP, FP, HP front-wheel-drive cars may alter body and suspension to install alternate transmission, transaxle, and axle shaft.
  • EP BMW Z3 2.5L Spec Line #31724wordingneutralEP BMW Z3 2.5L allows alternate throttle body from 92-95 325i with Turner adapter; head casting 1738400 permitted with specific blocks.
  • FV Update direct replacement connecting rod information #31843wordingneutralFV connecting rod suppliers clarified: Crower SP93280B and BrianCrower BC6417 allowed as direct replacements.
  • EP 944S2 Restrictor #31396inductionslowerEP Porsche 944S2 89-91 requires 56mm flat plate intake restrictor; comp ratio max 12.0:1, valve lift max 0.500".
  • EP Classing Clarification for 1986 Toyota Corolla FX16 #31527cars addedneutralHP Corolla GTS RWD (84-87) added at 2300 lbs; HP Corolla FX16 FWD (87-88) added at 2260 lbs; old Corolla (84-87) removed.
  • FV Formula V Connecting Rod Replacement #31448wordingneutralFV allows Crower SP93280B and Brian Crower Racing Rods as direct replacement connecting rods, must meet OEM minimum weight.
  • EP E&O; MR2 Track #31120wordingneutralHP Toyota MR-2 1.6L (85-89) track corrected to 15.47 inches front and rear.
  • EP Request to Allow F22c Engine for 2000-2003 Honda S2000 #30548cars addedunclearHonda S2000 (00-03) reclassified as EP Prep with F22c engine option: 1997cc or 2157cc, weight 2450–2636 lbs depending on displacement.
  • EP Request a review of the S14 240SX in EP. #30873weight -200 lbsfasterEP 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 Request #30392wordingunclearEP Lotus/Caterham 7 America carburetor changed from IT fuel injection prep to fuel injection.
  • EP Reclassify Daimler SP 250 #30721cars addedneutralDaimler SP 250 classified in EP at 2165 lbs with 2548 cc OHV 8-cylinder engine.
  • EP Clarify Application of Percentage Based Weight Penalties #30669weightslowerEP, FP, HP clarifies percentage weight penalties sum first, then apply to base weight, rounding to nearest pound.
  • EP Change Classification of 84-87 Mazda 626 from FP to HP #30350cars addedneutral84-87 Mazda 626 reclassified from FP to HP with 2300–2415 lbs weight, 1998cc SOHC, dual 32mm carbs.
  • EP Fiat X1/9 brake rotors #30423suspension & brakesneutralFP Fiat X1/9 brake rotors change to 257 (10.1) x 12 (.407) solid disc.
  • EP NC MX-5 year range correction E&O #30503wordingneutralEP Mazda MX-5 year range corrected from 06-14 to 06-15.
  • EP Please Classify Mazda3 in FP #30165cars addedneutralMazda 3 S 04-08 classified in EP at 2350 lbs minimum, 2.26L DOHC, 12.0:1 compression, .500" valve lift limit.
  • EP Alternate Front Brake Rotors and Calipers for EP AH 3000 #29893suspension & brakesneutralEP Austin-Healey 3000 Mk. I, II, III now allows TR-6 front calipers and discs as alternate.
  • EP Mk2 VW Consistency and Cleanup of FP and HP Spec Lines #29195weight -50 lbsfasterFP Volkswagen Golf and Jetta 1.8 lose 50 lbs each, to 1900. HP Jetta GLI engine code removed.
  • EP Correct Wording for Level 1 and Level 2 Induction Systems #29406wordingneutralEP, FP, HP Level 1 and Level 2 induction systems: clarified carburetor and fuel injection rules, jets/needles/rods unrestricted in Level 2.
  • EP Weight Reduction for Datsun Roadster #29409weight -75 lbsfasterEP Datsun SRL 311U Roadster minimum weight reduced to 1925 lbs from 2000 lbs.
  • EP EP TR8 Adjustment #29512weight -100 lbsfasterEP Triumph TR8 78-81 weight reduced from 2600 to 2500 lbs.
  • EP 84-87 Toyota Corolla HP Wheel Diameter Allowance Proposal E&O #29458tyres & wheelsfasterHP 84-87 Toyota Corolla wheel diameter increases from 13 to 15 inches.
  • EP EP BMW Z3 Rule Clarification #28998wordingneutralEP BMW Z3 2.5L iron block casting 1738566-C designation removed, wording clarification only.
  • EP Request to Classify Porsche 911 2.0L #28456cars addedneutralPorsche 911 S 67-68 classified in EP at three weight levels: 1800, 1845, or 1890 lbs.
  • FV Support for Recommended Item - 4 bolt wheels in FV #29084tyres & wheelsneutralFV now allows 4 bolt wheels, previously restricted to 5 bolt wheels.
  • FV Support for 4-bolt pattern wheels #28955 #29118wordingneutralFV now supports 4-bolt pattern wheels in addition to existing wheel specifications.
  • EP BMW Cylinder Head Casting and Part Numbers #28708engineslowerEP BMW 2.8L, 328i E36/E46, and 325i E36 blocks now iron only; 325i E46 aluminum only.
  • EP Request to Classify 1990-1994 Mazda Protege #28381cars addedneutral1990-1994 Mazda Protege classified in FP Pre at 2150–2258 lbs with 1839cc DOHC engine, fuel injection.
  • EP Error in Mini Cooper Spec Line #28713wordingneutralHP 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 #28498wordingneutralEP Caterham 7 Spec Line removes redundant suspension note, clarifies engine prep limits and comp ratio to 10.0:1.
  • EP Request to Review Horsepower Parity #27662engineslowerEP 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 E36 (92-95) Brakes Errors and Omissions #28058weightfasterEP BMW 325is M-Technic loses 100–105 lbs across three weight configurations, to 2550–2678.
  • EP Request to allow 40 DCOE carb for the Datsun 510 #28195inductionfasterHP Datsun 510 gains 40 DCOE carburetor option alongside existing 40 DCN and 36mm DCNVH choices.
  • EP Add Throttle Body Size these EP BMW Spec Lines #28422inductionslowerEP BMW fuel injected throttle body maximum inside diameter set to 64mm.
  • FV Update rain tire designation #28444tyres & wheelsneutralFV rain tire requirement changed to Hoosier #44266 22.5 x 5.0 x 15 WET or W3.
  • EP Request for Help for Datsun 1200 #27934inductionfasterHP Datsun 1200 carburetor choke size increases from 26mm to 30mm.
  • EP Request to List Mazda Miata Throttle Body Size #27907wordingneutralFP and EP Mazda Miata models standardized to 55mm throttle body diameter; brake spec clarified.
  • FV FV Allow non-spec tire in Regional competition #26284tyres & wheelsneutralFV allows non-spec Hoosier tires in Regional races until 2020-01-01, when spec tires become required.
  • FV Request to Allow Rear Tires on the Front of Formula Vee #26537tyres & wheelsneutralFV allows rear tires on front of car; mandates Hoosier #43337 fronts and #43353 rears, plus #44266 rain tire from 2020-01-01.
  • EP Re-organize Prep2 Cylinder Head Rules for Clarity & Consistency #27661wordingneutralEP, FP, HP cylinder head rules reorganized for clarity; no performance change.
  • FV Clarification on Wheel Bolt Pattern #27603wordingneutralFV wheels clarified: 15" x 4J standard or 15" x 4.5J steel VW, 5-bolt pattern, same track dimensions.
  • FV Allowed Modifications E&O #27398wordingneutralFV exhaust outlet location tightened to 1–4 inches behind rearmost body part.
  • EP Request bodywork for Austin Healey Bugeye Sprite MK1 #27106wordingneutralFP 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 Request to classify the GMX5 2019 #27263wordingneutralEP Mazda MX-5 Global Cup classification year changes from 16-18 to 16-19.
  • EP level one susp. component rule #27270wordingneutralProduction suspension rule clarifies spindles, hubs, bushings, bearings, ball joints unrestricted.
  • EP Clarification of Carb Rules - Prep 1 #27300wordingneutralProduction carb rules clarified: carburetor options, fuel injection throttle body dimensions, and intake manifold restrictions reorganised and refined.
  • EP Clarification of Carb Rules - Prep 2 #27301wordingneutralEP, FP, HP carburetors clarified: jets, needles, metering rods, needle valves unrestricted; choke parts removable; permitted optional carburetors listed.
  • FV E&O Wheels #27230tyres & wheelsneutralFV wheels now permit 15-inch 4.5J steel wheels within C.2 track dimensions, adding to standard 4J options.
  • EP Request Miata Eligibility - 2003 #27121cars addedneutralEP Mazda MX-5/Miata eligibility years expanded from 1999-2002 to 1999-2005.
  • FV Exhaust termination rule E&O #26702aeroneutralFV exhaust opening can now extend to 4 inches behind body rear, previously 3 inches maximum.
  • EP Allow Firewall Modification for Fitment of 13B into RX8 #26726wordingneutralEP Mazda RX-8 firewall modification allowed for 13B engine fitment in stock location.
  • FV E&O Dimensions #26674wordingneutralFV front track maximum 52.500" and rear track 49.125"-50.750" no longer prohibits spacers.
  • EP Rollcenter Correction Clarification #25873suspension & brakesfasterEP, FP, HP clarified: tapered holes in ball joints now allowed for bolt conversion; wheel bearings and hubs unrestricted at any wheel.
  • EP Hardtops #26476wordingneutralEP open cars may now use aftermarket hardtops if they retain OEM appearance; specific model hardtop allowances removed.
  • FV Request to clarify Disc Brake rules bearing retainer & weights #26262weightslowerFV disc brake assembly minimum weight clarified to 16.5 lbs total; caliper minimum weight requirement removed.
  • EP Request for Competition Adjustment for 2nd Generation RX7 #25935weight -50 lbsfasterEP Mazda RX-7 12A and 13B (79-85) lose up to 80 lbs; 13B (86-91) loses up to 79 lbs.
  • FV FV Intake Manifold Clarification #26008wordingneutralFV intake manifold horizontal tube measurement locations clarified between 1.500" and 8.000" on short side.

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