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BoP Lab / Buttonwillow Raceway Park

FE vs SRF vs FM vs T4 pace at Buttonwillow Raceway Park

FE at every track →

Lap times across years say as much about the weather as the class. % of FE is each class's best lap as a share of FE's on the same day, so the conditions drop out: 100% is level, less is quicker, and a move in it is the class getting faster or slower against the field.

Class · click a class to switch, + to compare alongside (up to 4: remove one to add another)
Reference class · the yardstick the % column and chart are measured against
Track configuration

Quickest here: T4 1:58.339 Oscar Jackson, Super Tour Feb 2025 qualifying

1:581:592:002:012:02204 rule changes between Super Tour Apr 2019 and Super Tour Feb 2025204 ▾25 rule changes between Super Tour Feb 2025 and Super Tour Feb 202625 ▾T4 race best at Super Tour Feb 2025: 1:59.922 (Oscar Jackson)T4 race best at Super Tour Feb 2026: 2:01.157 (Izzy Sanchez)T4 qualifying best at Super Tour Feb 2025: 1:58.339 (Oscar Jackson)T4 qualifying best at Super Tour Feb 2026: 2:01.678 (Izzy Sanchez)Super Tour Apr 2019Super Tour Apr2019Super Tour Feb 2025Super Tour Feb2025Super Tour Feb 2026Super Tour Feb2026
FESRFFMT4solid race · dashed qualifying · slower is lower
EventFESRFFMT4
Qual bestRace bestTrapQual bestRace bestTrapvs FE% of FEQual bestRace bestTrapvs FE% of FEQual bestRace bestTrapvs FE% of FE
Super Tour Feb 2026 CALCL262026-02-212:01.678Izzy Sanchez · fastest of 5 · top 5 within 5.9s+3.339s (+2.82%)2:01.157Izzy Sanchez · fastest of 5 · top 5 within 7.2s+1.235s (+1.03%)135.5Izzy Sanchez+27.2 mph (+25.1%)
25 rule changes (FE: 3, SRF: 3, T4: 19)4 cars added · 2 induction · 2 removed · 2 tyres & wheels · 1 aero · 1 engine · 1 suspension & brakes · 1 weight · 6 wording · 5 other · T2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously only spherical bearings permitted. · FE adds engine modification restrictions, testing requirements, and drivetrain violation penalties with competition suspension. · T2, T3, T4 now allow under-dash electronics relocation for access after roll cage installation. · T4 Performance clarified: 1-piece alternative rotors permitted only at sizes listed in spec line; alternate brake kits may use matching 1-piece rotors. · T3 and T4 Mazda MX-5 Miata add permitted gearset kit PT#0000-02-6100 to Notes. · T4 MX-5 Miata 19-24 and 16-18, T3 MX-5 16-18 and Global Cup ND1/ND: discontinued DG Motorsports hardtop part #0000-07-5901 removed from permitted list. · FE and FE2 Enterprise bubble tail part WM138014 now allowed; FE2 must use this configuration only. · SRF3 adds HD Oil Cooler P/N G1148500 option alongside standard P/N G480503, no fan permitted. · FE2 minimum weight stays 1270 lbs; intake manifold part number changes to WM301061; ECU to G992012; mandatory spec parts expanded; bubble tail WM138014 now FE only; SADEV transmission no modifications allowed; brake rotor part numbers to W… · T2, T3, T4 spec table header changed from T2 to ET. · 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.showhide
  • T4 T4 and T3 Feedback #39230removed
  • T4 T4 Mustang 4.0 #39489induction
  • T4 Allow Alt Bushing Material in Toe Links #39607suspension & brakesadded · suspension & brakesT2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously only spherical bearings permitted.
  • FE FE & FE2 Rule Updates #39484wordingwordingFE adds engine modification restrictions, testing requirements, and drivetrain violation penalties with competition suspension.
  • T4 Alternate Placement of Fuse Panel and Electronics Request #39370otheraddedT2, T3, T4 now allow under-dash electronics relocation for access after roll cage installation.
  • T4 Clarify T4 Brake Rotor Allowance #39503wordingwordingT4 Performance clarified: 1-piece alternative rotors permitted only at sizes listed in spec line; alternate brake kits may use matching 1-piece rotors.
  • T4 Classing 1995-99 Dodge Neon SOHC #39285cars added
  • T4 02-06 Mini Cooper Gear Ratios #38966other
  • T4 Reinstatement of the 2005-2010 Cobalt into T4 #38987cars added
  • T4 Request to Classify Mercedes C230K #39080cars added
  • T4 ND Gearset Request for T4 #39166otheraddedT3 and T4 Mazda MX-5 Miata add permitted gearset kit PT#0000-02-6100 to Notes.
  • T4 E&O wheel size on ND #39168tyres & wheels
  • T4 ND Spec Lines Wrong PT#'s #39170removedremovedT4 MX-5 Miata 19-24 and 16-18, T3 MX-5 16-18 and Global Cup ND1/ND: discontinued DG Motorsports hardtop part #0000-07-5901 removed from permitted list.
  • T4 Touring 4 Post-Runoffs BOP Adjustments and Changes #39251induction -100 lbs
  • FE FE & FE2 Bubble Tail #38978cars addedaddedFE and FE2 Enterprise bubble tail part WM138014 now allowed; FE2 must use this configuration only.
  • SRF Add HD Oil Cooler #38979engineadded · engineSRF3 adds HD Oil Cooler P/N G1148500 option alongside standard P/N G480503, no fan permitted.
  • FE FE & FE2 Rule Updates #38901wordingwordingFE2 minimum weight stays 1270 lbs; intake manifold part number changes to WM301061; ECU to G992012; mandatory spec parts expanded; bubble tail WM138014 now FE only; SADEV transmission no modifications allowed; brake rotor part numbers to W…
  • T4 Incorrect Touring Heading #38451wordingwordingT2, T3, T4 spec table header changed from T2 to ET.
  • T4 Allow B-Spec cars to run in T4 #38439other
  • T4 T4 Mustang #38059weight -100 lbs
  • T4 SSC tire allowance #38216tyres & wheels
  • T4 Correct Ring and Pinion Ratio to T3, Sorry I Mean T4 3.7 V6 Stang #38041wording
  • T4 T4 Mustang #38058aero
  • SRF Driver Safety & Comfort #37966otheraddedSRF drivers with disabilities may modify seat and controls for safety and comfort with SCCA approval, noted in logbook, for that driver only.
  • SRF Update SADEV transmission specs #37992wordingwordingSRF SADEV-SRF3 6-speed sequential transmission: effective date clarified to 1 April 2025 onward.
Super Tour Feb 2025 CALCL252025-02-221:58.339Oscar Jackson · fastest of 5 · top 5 within 8.3s1:59.922Oscar Jackson · fastest of 4 · top 4 within 7.3s108.4Tony Kiratsous
204 rule changes (FE: 26, SRF: 28, T4: 150)32 weight · 28 cars added · 25 suspension & brakes · 20 tyres & wheels · 9 aero · 8 engine · 5 induction · 3 removed · 43 wording · 31 other · Ford SCCA Club Spec Mustang added to T3 at 3350 lbs; Mazda SCCA Club Spec MX-5 added to T4 at 2500 lbs. · T2, T3, T4: nine, nine, and thirty-seven expired spec lines removed effective 2025-01-01. · FE must use SCCA Part # WM803010 Brake Line to Control Arm covers if used, as delivered, fastened with zip ties or tape only. · T2, T3 Mustang spec lines remove redundant driveshaft allowance notes across six model year ranges. · T2, T3, T4 fuel cell installations may omit charcoal canisters, emissions valves, and sensors. · T2, T3, T4 brake specifications clarified: 2-piece rotors allowed in T2 within 5% OE diameter, T3 within 2% OEM diameter. · T2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors. · Porsche Spec Boxster moves to T4, minimum weight 2750 lbs, ineligible for Runoffs until 3 Super Tour events. · T4 BMW 320i Spec Line: Turner Motorsports intercooler #024703TMS02 now allowed. · 2005 Cadillac CTS 3.6L 6-speed manual classified in T3 Spec. · 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. · FE Hoosier contingency decal requirement reduced from five decals in specific locations to three decals on sides and 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. · FE requires five Hoosier decals: one small on nose or front shock cover, one 12" on each front wing plate, one 12" on each lower floor panel before rear wheels. · 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. · T2 Mustang GT 5.0L 15-17 and 2018- now permit Track/Performance Package parts; T3 V6 15-17 clarified to allow Track/Performance package. · T2-T4 Ford Mustangs: remove 25 lb penalty for non-OEM driveshaft, clarify alternate driveshaft allowance. · Audi S4 (2000–2002) classified in T3 with 2671cc, 3400 lbs minimum weight, 38mm restrictor, allowing 800lb springs and intercooler. · T3 and T4 Mazda RX-8 may remove or disable factory oil injection system. · T2, T3, T4 driveshafts may use carbon fiber, aluminum, or steel; two-piece replaced with one-piece; non-OEM adds 25 lbs. · T2, T3, T4 Spec Lines remove wheelbase requirement, add Required Restrictor specification. · T2 and T3 Nissan 370Z front brake rotors increase to 355×32 mm, rears to 350×20 mm. · T2, T3, T4 battery replacement no longer allows alternate manufacturer batteries within 10% OEM weight. · T4 now allows C-Spec touring cars to compete, in addition to existing B-Spec eligibility. · T2, T3, T4 spec lines expire 12/31/24; submit to appeal or cars are removed from class. · FE rain light now must meet FIA Standard 8874-2019, Technical List No. 76, effective 1/1/2024. · FE allows racer's tape for crash repair, panel security, and heat exchanger opening control; seam taping banned. · 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. · T3 Nissan 370Z now includes model years 2009–2022 with Nismo editions. · SRF radiator options expanded: Enterprises P/N 480465 with baffle 480464, 480466, or Automotive 1R698 and CU698 allowed if cross-reference equivalent. · Mazda RX-8 T3 and T4 transmission and final drive pairing requirement removed; T4 gains Mazdaspeed radiator, spring kit, restrictor, spoiler, air dam. · T3 BMW 320i 14–15 gains aftermarket intercooler; T4 BMW 320i 14–15 loses it. · T3 and T2 Pontiac Solstice GXP 07-09 minimum ride height set to 3 inches. · 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. · FE SADEV transmission rule removes note that all ratios under review and could be updated prior to sealing. · 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. · T2 and T3 Mustang 11-14 may remove upper grille fog lights, replace with mesh or screen. · T5 touring class added; T2-T5 cars may race one class up; T5 maximum tyre width 225 with minimum aspect ratio 45. · T2-T5 Touring front and rear suspension maximum negative camber clarified to 3.5 degrees. · FE drivers may now adjust brake bias manually during the race. · FE front and rear wing specifications clarified: adjustment ranges, shimming, Gurney flap sizes, mounting hardware, and measurement references refined. · FE engine heat shield and insulation between block and exhaust now permitted to protect fuel cell, filter, rail, lines. · FE tires must be run as delivered in sets of 4. · FE master cylinders clarified: Girling front .700" piston WM802005, rear .750" piston WM802006. · 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. · T2-T4 Touring cars with alternative springs now permitted to use performance top hats with spherical bearings on shocks and struts. · T2-T4 touring cars model year 2018+ may use aftermarket ECU with 75 lb weight penalty via spec line adjustment. · T2-T4 grill opening removal for cooling permitted without 16 square inch limit; mesh shape must match factory. · T2, T3, T4 clarify grill opening removal limited to 16 square inches for radiator cooling; mesh shape must be retained. · T2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted. · T2, T3, T4: clarified that 'permitted' or 'allowed' parts in spec lines are alternatives to category rule allowances, not replacements. · 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… · T4 adds 2014 VW Jetta 1.8T TSI to Spec Lines. · 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. · SRF3 alternator pulley specified as P/N G902130 or G902130A, minimum 12oz. · T3 Honda Civic Type-R 2020+ allowed brake rotor #45251-TGH-A01 with 25 lb penalty. · T2-T4 clutch discs and pressure plates must be at least 95% of factory OEM weight, bolted to unmodified stock flywheel. · SRF and SRF3 mandatory identification revised: removed Ford Performance and Blue Oval decals, added Hoosier logo placement. · Toyota Supra 2020- added to T2 with 2998 cc engine, 3450 lbs minimum weight, 19×10 wheels, 295 tyres. · T2 BMW M2 CS Cup 2020+ classified at 2979 cc, 3625 lbs, 295 tires, 10.5×18 wheels, 380/390 mm brakes. · T4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.55 final drive, plus 25 lb penalty. · T3 Scion FR-S/Toyota 86 and Subaru BRZ capped to 2021 model year; T4 models capped to 2021. · FE front springs change to 800 lbs Hypercoil WM203013 Silver; rear to 900 lbs Hypercoil WM203014 Silver. · SRF rear springs limited to P/N 280390 only, previous part numbers no longer allowed; ground clearance wording clarified. · T3 Alfa Romeo 4C Launch Edition variant now allowed. · FE Gurney flaps clarified: front wing secondary only at 0.500" ±0.030", rear wing at 0.250" ±0.030". · Request to add vehicle to T2, T3, T4 roster; refer to letter #27663 in June 2020 Fastrack for decision. · FE Gurney flap wicker bill clarified: permitted on front wing secondary elements only, not main plane. · 2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine, 17-inch wheels, 245 tyres, EIBACH PN# 2563.140 springs allowed. · 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. · T3 BMW Z3 M & Coupe 98-99 minimum weight reduced to 3150 lbs. · Pontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18x9.5, Sky weight drops to 3200 lbs. · Mazda RX-8 Base/R3/Sport/GT (04-12) classified in T3 effective 2020-02-01. · 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. · T2 must have fire system installed; T3 and T4 may have one per GCR 9.3. · T3 Ford Mustang EcoBoost gains three transmission gear ratio options. · T3 and T4 Mazda RX-8 Base/R3 (04-12) reclassified to include Sport and GT variants. · Toyota 86 GT variant (2017–) added to T3 and T4 spec lines. · 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. · T2, T3, T4 spare tire and cover removal wording clarified; removable covers now explicitly allowable to remove. · 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
  • T4 Ford Mustang V6 (05-14) #37516other
  • T4 Request to Classify Club Spec in Appropriate Touring Classes #37523cars addedaddedFord SCCA Club Spec Mustang added to T3 at 3350 lbs; Mazda SCCA Club Spec MX-5 added to T4 at 2500 lbs.
  • T4 Remove spec lines that have expired #37269removedremovedT2, T3, T4: nine, nine, and thirty-seven expired spec lines removed effective 2025-01-01.
  • T4 2016-2018 Mazda Miata MX5 #37085weight -75 lbs
  • FE Brake Line to A-Arm Covers #37110otheraddedFE must use SCCA Part # WM803010 Brake Line to Control Arm covers if used, as delivered, fastened with zip ties or tape only.
  • T4 Redundant Verbiage Regarding Mustang Spec Lines for Driveshaft #36484wordingwordingT2, T3 Mustang spec lines remove redundant driveshaft allowance notes across six model year ranges.
  • T4 R53 Mini Cooper S Weight Reduction Request #36612weight
  • T4 Allowable Wheel Offset #36855tyres & wheels
  • T4 Fuel Emissions Components #37076otheraddedT2, T3, T4 fuel cell installations may omit charcoal canisters, emissions valves, and sensors.
  • T4 2019-2024 Mazda 3 for T4 #37077cars added
  • T4 fix brake wording #37129wordingwordingT2, T3, T4 brake specifications clarified: 2-piece rotors allowed in T2 within 5% OE diameter, T3 within 2% OEM diameter.
  • T4 Evaporative emissions systems #37130otheraddedT2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors.
  • T4 Allow Spec MX5 upgrade kit for 2009-11 RX8 S2 Transmision #37140other
  • T4 Move Spec Boxster to T4 #37158cars addedaddedPorsche Spec Boxster moves to T4, minimum weight 2750 lbs, ineligible for Runoffs until 3 Super Tour events.
  • T4 3.7 Mustangs to T4 #37188cars added
  • T4 BMW 320i Spec Line #37204engineadded · engineT4 BMW 320i Spec Line: Turner Motorsports intercooler #024703TMS02 now allowed.
  • T4 MX5 2006-2015 NC Help #37221other
  • T4 Classification for a 2005 Cadillac CTS 3.6 liter 6 speed manual #37224cars addedadded2005 Cadillac CTS 3.6L 6-speed manual classified in T3 Spec.
  • T4 Civic SI in T4 #37248weight -50 lbs
  • T4 2006-2015 T4 NC Mx5 spec line #37278weight
  • T4 ND MX-5 wheel allowance #37279tyres & wheels
  • T4 T4 BOP #37281weight +75 lbs
  • T4 Allow 7.5 #37286tyres & wheels
  • T4 Bop Request 06-11 Honda Civic Si #37013other
  • SRF Update SRF3 Air Filter Rule #36681wordingremovedSRF3 air filter rule removes K&N RC-9160 option, specifies Weems P/N WM301020 only.
  • SRF Update SRF Brake Rotor Thickness #36687suspension & brakessuspension & brakesSRF Wilwood vented rotor minimum thickness increases to 13.25mm, 0.522 inches.
  • SRF Hoosier Tire Decal Placement #36739wordingwordingSRF3 Hoosier decal placement changed from four logos on nose and tail to three logos on sides and center front.
  • FE Protest Fee Clarification #36540wordingwordingFE and SRF protest fee rules redirected to GCR section 8.3.1.D for fees and procedure.
  • FE Update on Letter 36620 with new Hoosier Contingency Decal Info #36625wordingwordingFE Hoosier contingency decal requirement reduced from five decals in specific locations to three decals on sides and front.
  • SRF Protest Fee Clarification #36540wordingwordingFE and SRF protest fee rules redirected to GCR section 8.3.1.D for fees and procedure.
  • SRF Update to Letter 36619 with new Hoosier Contingency Decal Info #36624wordingwordingSRF Hoosier contingency decal requirement reduced from four decals in specific locations to three decals with simplified placement.
  • FE Hoosier Tire Decal Placement #36435wordingaddedFE requires five Hoosier decals: one small on nose or front shock cover, one 12" on each front wing plate, one 12" on each lower floor panel before rear wheels.
  • SRF Update Rain Tire Rule and Hoosier Decal Placement #36436tyres & wheelstyres & wheelsSRF 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.
  • T4 T4 Camaro V6 weight reduction #36232weight
  • T4 BOP adjustment for ND MX5s #36345weight -50 lbs
  • T4 Mustang T2/T3 #35877cars addedaddedT2 Mustang GT 5.0L 15-17 and 2018- now permit Track/Performance Package parts; T3 V6 15-17 clarified to allow Track/Performance package.
  • T4 Homologation of car to T4 #36030cars added
  • T4 T2-T4 Driveshaft Mistake...? #36050weightfaster · weightT2-T4 Ford Mustangs: remove 25 lb penalty for non-OEM driveshaft, clarify alternate driveshaft allowance.
  • T4 MINI Cooper S Spec Lines Corrections. #36086removed
  • T4 Allow Removal of Sound Tubes #36130induction
  • T4 B8/8.5 Audi S4 T3 and T2 #36195cars addedaddedAudi S4 (2000–2002) classified in T3 with 2671cc, 3400 lbs minimum weight, 38mm restrictor, allowing 800lb springs and intercooler.
  • T4 Allow OEM Front Spoiler 06-08 Miata in T4 #35941aero
  • T4 T4 Mustang Weight Reduction In T4 Spec #36051weight -50 lbs
  • T4 R53 Mini Cooper S spec line request In #36056suspension & brakes
  • T4 Allow T4 and T3 RX8 to Disable/Remove Factory Oil Inj. #35761engineadded · engineT3 and T4 Mazda RX-8 may remove or disable factory oil injection system.
  • T4 2023 ND2 Miata Classification and Allowances #35837weight
  • T4 Errors and Omissions for 06-09 VW Rabbit Rotor #35851suspension & brakes
  • T4 Driveshafts #35916weightslower · weightT2, T3, T4 driveshafts may use carbon fiber, aluminum, or steel; two-piece replaced with one-piece; non-OEM adds 25 lbs.
  • T4 GCR ERROR - letter not properly applied to GCR #35999weight
  • T4 Corrections to T4 RX8 Spec line #35767aero
  • T4 Reorganize Spec Lines #35375otheraddedT2, T3, T4 Spec Lines remove wheelbase requirement, add Required Restrictor specification.
  • T4 Allow any 400lb rear spring in the RX8 #35433suspension & brakes
  • T4 370Z Brake Rotor Size Correction #35487suspension & brakessuspension & brakesT2 and T3 Nissan 370Z front brake rotors increase to 355×32 mm, rears to 350×20 mm.
  • T4 More Car Lightening Stuff #35319wordingremovedT2, T3, T4 battery replacement no longer allows alternate manufacturer batteries within 10% OEM weight.
  • T4 ND Missed Items #35352other
  • T4 Inclusion of B-C spec cars in T4 #35374cars addedaddedT4 now allows C-Spec touring cars to compete, in addition to existing B-Spec eligibility.
  • T4 T2-T4 Set expiration dates on spec lines #35378wordingremovedT2, T3, T4 spec lines expire 12/31/24; submit to appeal or cars are removed from class.
  • FE Update FE Rain Light Rule #34707wordingwordingFE rain light now must meet FIA Standard 8874-2019, Technical List No. 76, effective 1/1/2024.
  • FE FE/FE2 rule update #35269wordingwordingFE allows racer's tape for crash repair, panel security, and heat exchanger opening control; seam taping banned.
  • SRF Update SRF Rain / Brake Rule #34706otherotherSRF rain/brake light must be Super Bright LEDs Inc. P/N PT-STRB-R24; secondary filament must connect to rain light switch.
  • SRF Update SRF Brake Light Rule v1 #34853otherotherSRF 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 SRF / SRF3 Rule Updates #35268suspension & brakessuspension & brakesSRF 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.
  • T4 Mazda MX-5 ND1 Spec Line Request #34232weight +50 lbs
  • T4 BRZ/FRS/86 Spring Allowance #35038suspension & brakes
  • T4 TSX Allowance #35219other
  • T4 Requested Update of Model Years of 370Z #35231cars addedaddedT3 Nissan 370Z now includes model years 2009–2022 with Nismo editions.
  • SRF SRF Radiator Rule Update #34805otheraddedSRF radiator options expanded: Enterprises P/N 480465 with baffle 480464, 480466, or Automotive 1R698 and CU698 allowed if cross-reference equivalent.
  • T4 Inclusion of similar car. (CLK 320) #34626other
  • T4 Rules Clarification for Mazda RX8 Spec Line #34395wordingwordingMazda RX-8 T3 and T4 transmission and final drive pairing requirement removed; T4 gains Mazdaspeed radiator, spring kit, restrictor, spoiler, air dam.
  • T4 rule book corrections #34437otheraddedT3 BMW 320i 14–15 gains aftermarket intercooler; T4 BMW 320i 14–15 loses it.
  • T4 Ride Height Correction for the T3 Solstice. #34615suspension & brakessuspension & brakesT3 and T2 Pontiac Solstice GXP 07-09 minimum ride height set to 3 inches.
  • T4 2002-2006 Mini Cooper S R53 Spec Line Request #34336weight -50 lbs
  • SRF Hoosier SRF Wet Front Tire Rule Update #34189tyres & wheelstyres & wheelsSRF wet front tyre changes to Hoosier P/N 46100 P185/60R13 H20 or W2 with 2.5" ground clearance.
  • T4 05-06 Mini Wheel Weight #34112weight
  • T4 06-09 VW Rabbit #34153induction
  • T4 96-01 Audi a4 2.8 Spring Rate #34217suspension & brakes
  • SRF Update SRF Front W2 Rain Tire Part Number #34118tyres & wheelstyres & wheelsSRF front W2 rain tyre Hoosier part number changes from 46100 to 46101 P185/65R13.
  • FE Update FE SADEV Transmission Rule #33883wordingwordingFE SADEV transmission rule removes note that all ratios under review and could be updated prior to sealing.
  • T4 Request to Classify 2004-2008 Acura TSX in T4 #33590cars added
  • T4 T4 Mustang Brakes/Swaybar #34036suspension & brakes
  • SRF Update SRF Brake Rule #33469enginefaster · engineSRF 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.
  • T4 BMW 320I intercooler #33762other
  • T4 2019-2021 Mazda MX5 ND2 #32027cars added
  • T4 Mustang OEM Grill Request #33333aeroadded · aeroT2 and T3 Mustang 11-14 may remove upper grille fog lights, replace with mesh or screen.
  • T4 Mazda OEM LSD was letter 32655 typo #33666wording
  • T4 Allowable Springs and Sway Bars for 06-11 Civic si Spec Line #33294suspension & brakes
  • T4 Touring (T2-T5) Category #33617cars addedaddedT5 touring class added; T2-T5 cars may race one class up; T5 maximum tyre width 225 with minimum aspect ratio 45.
  • T4 ENO 9.1.9.2.D.1.e.1.a. #33651wordingwordingT2-T5 Touring front and rear suspension maximum negative camber clarified to 3.5 degrees.
  • T4 T4 mustang #32789weight -25 lbs
  • T4 Mazda OEM LSD was letter 32655 #32933weight -25 lbs
  • FE Brake bias adjuster clarification #33084suspension & brakesadded · suspension & brakesFE drivers may now adjust brake bias manually during the race.
  • FE FE Front and Rear Wing Update & Clarification #33089wordingwordingFE front and rear wing specifications clarified: adjustment ranges, shimming, Gurney flap sizes, mounting hardware, and measurement references refined.
  • T4 Another 2022 BRZ/86 T3 request #32945weight +225 lbs
  • FE Engine Heat Shield & Insulation #33019otheraddedFE engine heat shield and insulation between block and exhaust now permitted to protect fuel cell, filter, rail, lines.
  • T4 04-09 Mazda3 Balance Shaft Delete Kit #32795other
  • FE Update FE/FE2 Tire Rule #32613wordingwordingFE tires must be run as delivered in sets of 4.
  • FE Master cylinder clarification #32669wordingwordingFE master cylinders clarified: Girling front .700" piston WM802005, rear .750" piston WM802006.
  • SRF SRF Tire Rule Update #32614wordingwordingSRF tire rule wording clarified: tires must be run as delivered.
  • SRF Brake, seal, and air filter clarifications #32670otherfasterSRF brake rotor minimum thickness reduced from 13.25 mm to 12.20 mm; seals and air filter specs clarified.
  • T4 Request Wider Wheels for Hyundai Tiburon #32536tyres & wheels
  • T4 Request to Add Spec Line for 2004-2009 Mazda3 i 2.0 #32395weight
  • T4 Request Alternate Front & Rear Strut/Shock Top Hats #32452suspension & brakesadded · suspension & brakesT2-T4 Touring cars with alternative springs now permitted to use performance top hats with spherical bearings on shocks and struts.
  • T4 Request to Allow the Use of Aftermarket ECU's in Touring #31067engineadded · engineT2-T4 touring cars model year 2018+ may use aftermarket ECU with 75 lb weight penalty via spec line adjustment.
  • T4 Request JWT BSR Kit for 02-06 Nissan Sentra SE-R/Spec V #31685other
  • T4 Please Confirm Touring 4 (98-00) BMW 323 is E46 generation #31972other
  • T4 RX-8 Spring Part Numbers (E&O) #32151suspension & brakes
  • T4 04-09 Mazda3 Tire Limit Clarification #32249tyres & wheels
  • T4 Shock Part Number Errors & Omissions #32252suspension & brakes
  • T4 Update Solo Spec Coupe to latest '20 specs for Road Racing #32262other
  • T4 Request 2016 Mazda MX5 springs #32265suspension & brakes
  • T4 Reply to letter #31486/29879 T2-T4 Grill openings #31935aerofaster · aeroT2-T4 grill opening removal for cooling permitted without 16 square inch limit; mesh shape must match factory.
  • T4 BRZ vs BRZ TS #32022tyres & wheels
  • T4 MX-5 Durability Detailed #31102weight
  • T4 Request Allowances for 2005 - 2010 Mustang #31624wording
  • T4 Reply to letter 29879 T2-T4 Grill Openings #31486wordingwordingT2, T3, T4 clarify grill opening removal limited to 16 square inches for radiator cooling; mesh shape must be retained.
  • T4 Please Adjust 98-00 BMW 323 Min Weight to Reflect Current Class #31595weight -200 lbs
  • T4 Consolidate 12-13 and 14-15 Honda Civic Si spec lines for T4 #31596removed
  • T4 Request to clarify radiator hoses #31682otheraddedT2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted.
  • T4 Clarify Permitted/Allowed #31743wordingwordingT2, T3, T4: clarified that 'permitted' or 'allowed' parts in spec lines are alternatives to category rule allowances, not replacements.
  • T4 Correct RSX wording #31746tyres & wheels
  • T4 Camaro #31751suspension & brakes
  • FE Two FE2 Rule Updates #31524other
  • 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…
  • T4 Nissan Sentra SE-R Spec. V #30958cars added
  • T4 Mazda RX-8 Spec Line Suspension Parts #31113induction
  • T4 Diverter Valve Plunger Upgrade #31307engine
  • T4 Adjust Honda FWD in T4 to encourage more Drivetrain Diversity #31472tyres & wheels
  • T4 Touring 4 BOP adjustments for 2022 #31482weight -175 lbs
  • T4 Request to Classify 2014 VW Jetta 1.8t TSI #30436cars addedaddedT4 adds 2014 VW Jetta 1.8T TSI to Spec Lines.
  • SRF SRF Wet Tires #30849tyres & wheelsadded · tyres & wheelsSRF wet tyres add Hoosier W2 option alongside existing H20 from October 4, 2021.
  • 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.
  • 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.
  • FE FE Tire Rule Changes #30754wordingwordingFE removes qualifying tire marking requirements and rain tire set rules; renumbers tire warmer prohibition.
  • FE Radiator Screens Clarification #30792wordingwordingFE radiator screens may not protrude more than ¼ inch in front of the outside vertical plane of the sidepods.
  • T4 Wrong Part Number on 320i Spec Line #30645wording
  • FE FE Radiator Screens #30575aeroadded · aeroFE radiator screens now allowed, maximum ¼ inch from sidepod front vertical plane.
  • SRF SRF3 Alternator Pulley #30684engineadded · engineSRF3 alternator pulley specified as P/N G902130 or G902130A, minimum 12oz.
  • T4 Civic Type R Brake Rotors #29817weightslower · weightT3 Honda Civic Type-R 2020+ allowed brake rotor #45251-TGH-A01 with 25 lb penalty.
  • T4 Mini Cooper Spec Line Anomalies #30478weight
  • T4 Request CAI Mustang in T4 #30562induction
  • T4 Request consistency review in GCR #30263wordingwordingT2-T4 clutch discs and pressure plates must be at least 95% of factory OEM weight, bolted to unmodified stock flywheel.
  • SRF Mandatory identification: #30223wordingwordingSRF and SRF3 mandatory identification revised: removed Ford Performance and Blue Oval decals, added Hoosier logo placement.
  • T4 E & O T4 Mustang Wheels #30245tyres & wheels
  • T4 2021 Toyota Supra #29567cars addedaddedToyota Supra 2020- added to T2 with 2998 cc engine, 3450 lbs minimum weight, 19×10 wheels, 295 tyres.
  • T4 06-15 MX-5 Durability #29781other
  • T4 Request for Update to T4 Spec Line for Chevrolet Sonic (2011-) #29838induction
  • T4 NC MX-5 06-15 Part Number updates for 2021 #29921weight
  • T4 BMW Z4 2.5L (03-05) Spec Line #30037weight -50 lbs
  • T4 Sway Bars for T4 2016+ MX5 Mazda #30063suspension & brakes
  • T4 Change part numbers on BRZ, FRS lines in T4 #30104wording
  • T4 T4 Mustang Axle Ratio and Wheels #30149tyres & wheels
  • T4 Request to Classify BMW M2 CS #29523cars addedaddedT2 BMW M2 CS Cup 2020+ classified at 2979 cc, 3625 lbs, 295 tires, 10.5×18 wheels, 380/390 mm brakes.
  • T4 Allow the SpecMX-5 Update Kit Into Touring 4 for the MX-5 #29681other
  • T4 Request Mustang 8.8” rear axle replacement #29860cars addedaddedT4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.55 final drive, plus 25 lb penalty.
  • T4 Cap year range on all 86s #29908wordingwordingT3 Scion FR-S/Toyota 86 and Subaru BRZ capped to 2021 model year; T4 models capped to 2021.
  • FE FE / FE2 Spring Updates #29689suspension & brakessuspension & brakesFE front springs change to 800 lbs Hypercoil WM203013 Silver; rear to 900 lbs Hypercoil WM203014 Silver.
  • 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.
  • T4 Alfa Romeo 4C Launch Edition #29531cars addedaddedT3 Alfa Romeo 4C Launch Edition variant now allowed.
  • T4 Post Runoffs Feedback for T4 #29752tyres & wheels -50 lbs
  • 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".
  • T4 Scion FRS Solo Spec Coupe Gear Ratio #29021other
  • T4 T4 RX8 bodywork clarification #28941aero
  • T4 2006-2015 MX-5 Clarification #28942tyres & wheels
  • T4 Request to Add a Vehicle to the Roster (contd.) #27698wordingunclearRequest to add vehicle to T2, T3, T4 roster; refer to letter #27663 in June 2020 Fastrack for decision.
  • FE FE Gurney flap wicker clarification #28885wordingwordingFE Gurney flap wicker bill clarified: permitted on front wing secondary elements only, not main plane.
  • T4 Request to Classify 2004 Mercedes Benz 320 CLK #27663cars addedadded2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine, 17-inch wheels, 245 tyres, EIBACH PN# 2563.140 springs allowed.
  • 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.
  • 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.
  • T4 Request to change allowed header part # for T4 06-15 Miata #28223wording
  • T4 Z3M Roadster Weight #28437weightfaster · weightT3 BMW Z3 M & Coupe 98-99 minimum weight reduced to 3150 lbs.
  • T4 Request for 12-13 and 14-15 Honda Civic Springs #27848suspension & brakes
  • T4 Request to Clarify T4 05-10 Mustang Spring Allowance #27899suspension & brakes
  • T4 Request to Allow Brake Upgrade on T4 Mustang #27329suspension & brakes
  • T4 Please Switch the Solstice GXP as Specified in T2, to T3 #27413cars added -50 lbsfaster · cars addedPontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18x9.5, Sky weight drops to 3200 lbs.
  • T4 Request to Classify all Mazda RX8 Models in T3/T4 #27606cars addedaddedMazda RX-8 Base/R3/Sport/GT (04-12) classified in T3 effective 2020-02-01.
  • T4 Request for 2014-2018 Mazda 3 GT Brakes #27659suspension & brakes
  • T4 Request to allow aftermarket OEM coolant expansion tank #27763engine
  • T4 Request to allow aftermarket OEM power steering reservoir #27764wording
  • T4 Request for Factory Installed Wings on Subaru BRZ #27831other
  • T4 Request for Replacement Clutches #27892other
  • T4 Request to Classify Chevy Sonic 1.4 In T4 #27906cars added
  • T4 Weight Change Request for 1999 Mazda Miata #28129weight -50 lbs
  • 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.
  • T4 Clarification of On-Board Fire System for T2 #27183wordingwordingT2 must have fire system installed; T3 and T4 may have one per GCR 9.3.
  • T4 Mustang Ecoboost and GT Transmission #27439cars addedaddedT3 Ford Mustang EcoBoost gains three transmission gear ratio options.
  • T4 BRZ/FRS/86 Tire Size in T4 #27660tyres & wheels
  • T4 NC MX5 2006-2015 Spec Adjustment Request #27739weight -75 lbs
  • T4 T4 RX8 Classification Error #27902cars addedaddedT3 and T4 Mazda RX-8 Base/R3 (04-12) reclassified to include Sport and GT variants.
  • T4 Request to add Toyota 86 GT to Spec Line #27910cars addedaddedToyota 86 GT variant (2017–) added to T3 and T4 spec lines.
  • 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.
  • 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.
  • SRF SRF Tire Warmer Rule #27622tyres & wheelstyres & wheelsSRF adds tire warmer prohibition and specifies Hoosier dry and wet tire part numbers.
  • SRF SRF / SRF3 Nose Weight Reduction #27706weightfaster · weightSRF front nose weight minimum reduced from 35 to 32 lbs.
  • 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.
  • 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.
  • T4 Request spare tire/wheel clarification #27012wordingfasterT2, T3, T4 spare tire and cover removal wording clarified; removable covers now explicitly allowable to remove.
  • T4 Research E&O Mazda MX5 #27112weight
  • 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.
  • SRF SRF Dash Windscreen Kit #27028aeroadded · aeroSRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102.
  • T4 MR2 Spyder Year Correction #26936wording
  • 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.
  • FE FE / FE2 Updated Bubble Tail Rule #26913aeroadded · aeroFE and FE2 Enterprise bubble tail P/N WM138014 newly allowed for both classes.
  • T4 Request to allow piggy back ECU on 2000 Mazda Protégé #26085engine
  • T4 Request helper spring as optional #26678suspension & brakes
Super Tour Apr 2019 ST19APR262019-04-26
11 earlier rule changes on record, in force before Super Tour Apr 2019 (from 2019)3 cars added · 2 suspension & brakes · 1 engine · 1 induction · 1 tyres & wheels · 3 wording · FE Hoosier rain tyre part numbers updated: front 44195 W3, rear 44217 W3. · T4 and T3 Mazda MX-5 hardtop rules clarified: any OEM or aftermarket top permitted if retaining OEM silhouette; specific part numbers listed. · T2, T3, T4 now allow any thermostat serving original equipment intent only. · T3 and T4 Mazda MX-5 Miata eligibility capped at 2016–2018 model years. · T4 Celica GT wheelbase 2600 and 15x7 wheels added; Forte years narrowed; Fiesta ST starts 2014; Fiat 124 years 16-18 added; battery rule clarified. · T1–T4 spec car classifications clarified with permitted parts, rule conformance versions, and exclusions of other touring modifications. · T2–T4 subframe bushings now permitted to be replaced with non-spherical bushings of any material.showhide
  • T4 Request to classify 2000 - 2001 BMW 323 #25096cars added
  • 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.
  • T4 Correct Mazda MX-5 Hard Top Notes #26137wordingwordingT4 and T3 Mazda MX-5 hardtop rules clarified: any OEM or aftermarket top permitted if retaining OEM silhouette; specific part numbers listed.
  • T4 Consider opening class rules to allow any thermostat #26187engineadded · engineT2, T3, T4 now allow any thermostat serving original equipment intent only.
  • T4 Cap 2016 Mazda Miata year at 2018 #26388cars addedremoved · cars addedT3 and T4 Mazda MX-5 Miata eligibility capped at 2016–2018 model years.
  • T4 2012-2015 Honda Civic Si Performance Request #26129suspension & brakes
  • T4 Errors, Omissions, and Updates (Various) #22414wordingwordingT4 Celica GT wheelbase 2600 and 15x7 wheels added; Forte years narrowed; Fiesta ST starts 2014; Fiat 124 years 16-18 added; battery rule clarified.
  • T4 Request for Adjustments to fiat 124 specline #25371induction
  • T4 Add Clarification to Spec Car Classifications Vehicle Spec #25774wordingwordingT1–T4 spec car classifications clarified with permitted parts, rule conformance versions, and exclusions of other touring modifications.
  • T4 Clarify Subframe Bushings Permitted for T2-T4 #25800suspension & brakesadded · suspension & brakesT2–T4 subframe bushings now permitted to be replaced with non-spherical bushings of any material.
  • T4 Consider Solo SSC cross over classification into T4 #25802cars added
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 FE" is the class's best as a share of FE'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 FE'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.