Quickest here:T4 1:58.339 Oscar Jackson, Cal Club 2025 qualifying
GT3T4solid race · dashed qualifying · slower is lower
Event
GT3
T4
Qual best
Race best
Trap
Qual best
Race best
Trap
vs GT3
Cal Club 2026 CALCL262026-02-21
2:01.678Izzy 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%)
22 rule changes (GT3: 3, T4: 19)3 cars added · 3 suspension & brakes · 3 tyres & wheels · 3 weight · 1 aero · 1 induction · 1 removed · 7 wording · Ford Mustang V6 (05-14) removed from T4 Spec Lines. · T4 Mustang 4.0 V6 tire size increases from 245 to 255. · T2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously prohibited except in specified examples. · GT3U cars must maintain 3.0" minimum ride height on frame rails and 2" minimum on front spoiler and splitter. · T2, T3, T4 cars may relocate under-dash electronics and fuse boxes for access after roll cage installation. · T4 Performance now permits 1-piece alternative rotors matching spec line sizes; alternate brake kits allowed same. · Dodge/Plymouth Neon ACR SOHC/DOHC 95-99 newly classified T4 at 2350 lbs minimum weight. · T4 Mini Cooper S R53 02-06 gear ratios changed to 12.79, 7.79, 5.65, 4.62, 3.83, 3.13 or 11.42, 7.18, 5.39, 4.40, 3.65, 2.96. · Chevrolet Cobalt SS Sport Coupe 06-10 reinstated to T4 with 2384cc engine, 2628 restrictor, 2700 lbs minimum weight. · Mercedes C230 Kompressor 2002-2005 classified in T4 at 3240 lbs with 17-inch wheels and 300/290 mm brakes. · T3 and T4 Mazda MX-5 Miata models add approved gear kit PT#-0000-02-6100 to notes. · T4 Mazda MX-5 Miata/Club 16-18 wheel size changed to 17 x 7.5 inches. · T4 Mazda MX-5 Miata/Club/RF (19-24) and (16-18) remove discontinued hardtop part #0000-07-5901; T3 MX-5 Miata (16-18) and Global Cup ND (16-21) same. · GT3U cars with 15×7" wheels add 225 lbs to GT3 weight; wider wheels allowed with weight penalties up to 3.0%. · T2, T3, T4 Spec Lines table header changed from T2 to ET. · T4 now permits B-Spec and C-Spec cars to compete in the class. · T4 Ford Mustang V6 05-14 weight drops from 3400 to 3300 lbs. · T4 Scion FR-S and Subaru BRZ Solo Spec allow any 200TW 225/45/17 or 215/45/17 DOT tire. · GT3U with 15x7 wheels and 225 tires gains 75 lbs to 225 lbs over GT3 weight; wheel weight penalties clarified. · T4 Ford Mustang V6 05-14 allows GT 8.8 rear axle or 7.5 axle with 3.45:1 ratio. · T4 Ford Mustang V6 05-14 now permits OEM style rear deck spoiler similar to Laguna/CS packages.showhide
T4 T4 and T3 Feedback #39230removedneutralFord Mustang V6 (05-14) removed from T4 Spec Lines.
T4 T4 Mustang 4.0 #39489tyres & wheelsfasterT4 Mustang 4.0 V6 tire size increases from 245 to 255.
T4 Allow Alt Bushing Material in Toe Links #39607suspension & brakesfasterT2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously prohibited except in specified examples.
GT3 GT3U Ride Height #39637suspension & brakesneutralGT3U cars must maintain 3.0" minimum ride height on frame rails and 2" minimum on front spoiler and splitter.
T4 Alternate Placement of Fuse Panel and Electronics Request #39370wordingneutralT2, T3, T4 cars may relocate under-dash electronics and fuse boxes for access after roll cage installation.
T4 Clarify T4 Brake Rotor Allowance #39503suspension & brakesneutralT4 Performance now permits 1-piece alternative rotors matching spec line sizes; alternate brake kits allowed same.
T4 02-06 Mini Cooper Gear Ratios #38966wordingunclearT4 Mini Cooper S R53 02-06 gear ratios changed to 12.79, 7.79, 5.65, 4.62, 3.83, 3.13 or 11.42, 7.18, 5.39, 4.40, 3.65, 2.96.
T4 Reinstatement of the 2005-2010 Cobalt into T4 #38987cars addedneutralChevrolet Cobalt SS Sport Coupe 06-10 reinstated to T4 with 2384cc engine, 2628 restrictor, 2700 lbs minimum weight.
T4 Request to Classify Mercedes C230K #39080cars addedneutralMercedes C230 Kompressor 2002-2005 classified in T4 at 3240 lbs with 17-inch wheels and 300/290 mm brakes.
T4 ND Gearset Request for T4 #39166wordingneutralT3 and T4 Mazda MX-5 Miata models add approved gear kit PT#-0000-02-6100 to notes.
T4 E&O wheel size on ND #39168tyres & wheelsunclearT4 Mazda MX-5 Miata/Club 16-18 wheel size changed to 17 x 7.5 inches.
T4 ND Spec Lines Wrong PT#'s #39170wordingneutralT4 Mazda MX-5 Miata/Club/RF (19-24) and (16-18) remove discontinued hardtop part #0000-07-5901; T3 MX-5 Miata (16-18) and Global Cup ND (16-21) same.
GT3 Declassify TCR Cars from GT3/GT3U #38569weightslowerGT3U cars with 15×7" wheels add 225 lbs to GT3 weight; wider wheels allowed with weight penalties up to 3.0%.
T4 Incorrect Touring Heading #38451wordingneutralT2, T3, T4 Spec Lines table header changed from T2 to ET.
T4 Allow B-Spec cars to run in T4 #38439wordingneutralT4 now permits B-Spec and C-Spec cars to compete in the class.
T4 T4 Mustang #38059weight -100 lbsfasterT4 Ford Mustang V6 05-14 weight drops from 3400 to 3300 lbs.
T4 SSC tire allowance #38216tyres & wheelsneutralT4 Scion FR-S and Subaru BRZ Solo Spec allow any 200TW 225/45/17 or 215/45/17 DOT tire.
GT3 Clarification of GT3U #38266weightslowerGT3U with 15x7 wheels and 225 tires gains 75 lbs to 225 lbs over GT3 weight; wheel weight penalties clarified.
T4 Correct Ring and Pinion Ratio to T3, Sorry I Mean T4 3.7 V6 Stang #38041wordingneutralT4 Ford Mustang V6 05-14 allows GT 8.8 rear axle or 7.5 axle with 3.45:1 ratio.
T4 T4 Mustang #38058aeroneutralT4 Ford Mustang V6 05-14 now permits OEM style rear deck spoiler similar to Laguna/CS packages.
Cal Club 2025 CALCL252025-02-22
1:58.339Oscar Jackson · fastest of 5 · top 5 within 8.3s
1:59.922Oscar Jackson · fastest of 4 · top 4 within 7.3s
108.4Tony Kiratsous
255 earlier rule changes on record, in force before Cal Club 2025 (from 2019)54 cars added · 41 weight · 21 suspension & brakes · 18 induction · 13 engine · 13 tyres & wheels · 9 aero · 2 removed · 76 wording · 8 other · T4 Ford Mustang V6 (05-14) final drive set to 3.45, GT/CS front bumper cover permitted with front fascia. · Ford SCCA Club Spec Mustang classified T3 at 3350 lbs with driver; Mazda SCCA Club Spec MX-5 classified T4 at 2500 lbs with driver. · TA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof requirement. · GT3 VW Fun Cup Beetle Sealed exempt from 150 lbs consolidation add-on weight. · T2, T3, T4 remove nine, nine, and thirty-six expired spec lines respectively, effective 2025-01-01. · T4 2016-2018 Mazda Miata MX-5 minimum weight reduced to 2575 lbs from 2650 lbs. · GT3 Pontiac LE5 Ecotech minimum weight drops 150 lbs to 2195. · T2 and T3 Mustang spec lines remove redundant driveshaft alternate/aluminum allowance wording. · T4 Mini Cooper S R53 now allows Alta 15% Pulley #AMPENG20X. · T4 removes restriction on aftermarket wheel weight minimum of 15 lbs. · T2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors. · Mazda 3 (19-24) newly classified in T4 at 2850 lbs with 17×8 wheels and 245 tires. · T2, T3, T4 brake component wording clarified: 2-piece rotors allowed in T2 within 5% OE diameter, T3 within 2% OEM diameter. · T2, T3, T4 fuel cell cars may remove charcoal canisters, emissions valves, and sensors. · T3 and T4 Mazda RX-8 and MX-5 permit transmission kit #0000-02-5700. · Porsche Spec Boxster moves to T4, minimum weight 2750 lbs, requires 3 Super Tour events before Runoffs eligibility. · Ford Mustang V6 (05-14) newly classified to T4 with 50mm restrictor, 3400 lbs minimum weight. · T4 BMW 320i 14-15 Spec Line expires 12/31/24 removed; Turner Motorsports intercooler #024703TMS02 allowed. · Unable to summarize: rule changes specified in letter #37281, not provided. · Cadillac CTS 02-07 3.6L classified in T3. · T4 Honda Civic Si 06-11 minimum weight drops 50 lbs to 2900, restrictor clarified. · T4 NC MX-5 06-15 removes SM5 suspension allowance, clarifies Mazda Motorsports LSD part number, adds weight penalty for other LSDs. · T4 Mazda MX-5 Miata/Club (16-18) wheel size changes to 17 x 7.5 inches. · T4 Mazda RX-8 gets 59mm restrictor and 3200 lbs; MX-5 Club drops to 2550 lbs. · T4 Mazda MX5 Miata/Club/RF 19-24 wheel size changes to 17 x 7.5. · GT3 Mazda 13B Bridgeport and Peripheral Port both drop to 2275 lbs minimum weight. · GT3 Nissan MR20DE DOHC engine classified with 1997cc displacement, 32mm restrictor, 2060 lbs minimum weight. · GT3 Mazda 13B minimum weight drops 175 lbs to 2175 lbs. · GT3 Mazda 12A peripheral port minimum weight reduced to 2100 lbs. · T4 Honda Civic Si 06-11 permitted to use LSD per category rules. · GT3 Mazda 3TC classified in TCR with 2950 lbs minimum weight, effective 11/1/2024. · GT3 adds Datsun 1200 B110 (70–73), 90.6 in wheelbase, engine per GT3 spec or alternate Nissan request. · GT3-TCR Honda Civic Type R, Audi RS3 LMS, Hyundai I30N, Volkswagen GTI weights adjusted; Hyundai down 100 lbs to 3154, VW down 100 lbs to 3077. · T4 Chevrolet Camaro V-6 (96-02) weight reduced from 3250 lbs to 3150 lbs. · T4 Mazda MX-5 Miata/Club 16-18 drops 50 lbs to 2650; 19-24 RF drops 50 lbs to 2750. · GT3 Pontiac Sunfire GT weight reduction corrected from 150 lbs to 75 lbs. · GT3 Mazda MZR removes second DOHC option, fuel induction now unrestricted. · Ford Mustang GT 5.0L and V6 now permit Track/Performance Package parts in T2 and T3. · Mercedes C300 4Matic 2008-2011 homologated to T4 at 3,725 lbs with 18x8.5 wheels, 245 max tires, 3.27 final drive. · T2-T4 Ford Mustangs: remove 25 lbs penalty for non-OEM driveshaft, clarify alternate driveshaft allowances. · T4 Mini Cooper S (02-04) deleted; (05-06) model year corrected to R53; (07-13) R56 simplified specs; (2014-2023) added with spring rates. · T4 OEM intake chambers, resonators and acoustic devices may be removed if ports sealed and before restrictor. · Audi S4 (2000-2002) moves to T3 with 3400 lbs minimum weight, 38mm turbo inlet restrictor required. · GT3 cars may run +1mm SIR above spec with 175 lb weight penalty added. · GT3 turbocharged 1401-1850cc four-valve engine with 35mm restrictor reduced to 34mm, weight to 2250 lbs. · T4 Mazda MX-5 Club 06-15 now permits OEM front spoiler NF51-V4-900F. · T4 Ford Mustang V6 (05-10) weight reduced 50 lbs to 3225. · T4 Mini Cooper S 02-04 and 05-06 now allow Milltek exhaust manifold #SSXM459 and 25mm rear sway bar. · GT2-ST Acura NSX minimum weight raised to 3000 lbs, restrictor increased to 45mm TIR. · GT3 Ford Duratech now allows hood bulge with no openings. · GT3 Acura K20A RSX body disenfranchised from GT2 adds 75 lbs weight penalty. · GT3 Toyota 4Y engine classified at 2030 lbs with unrestricted fuel induction. · GT3 Toyota model designation changes from DR86 to GR86. · GT3 Honda spec lines change engine family designation from bore/displacement to K20C1 and K24 model numbers. · GT3 Mazda spec line numbering changed from 4 to Model, unrestricted to 323, and 2195 to 626. · T3 and T4 Mazda RX-8 may remove or disable factory oil injection system. · T4 Mazda MX5 Miata/Club/RF year range extended to 2024, suspension package permitted with 100 lbs weight increase. · T4 Volkswagen Rabbit 2.5 (06-09) front brakes increase from 228 to 288 vented disc. · T2, T3, T4 driveshafts may use alternative materials or one-piece units; non-OEM adds 25 lbs. · T4 Mazda MX-5 Miata/Club 16-18 removes differential stock requirement, allows up to 500lb front and 300lb rear springs. · T4 Mazda RX-8 allows Mazdaspeed radiator, coil spring kit, OE rear spoiler, front air dam, springs to 700 lb front/400 lb rear, oil metering pump bypass, sway bars to 32 mm front/19 mm rear. · GT3 Miata Turbo restrictor increases to 35 mm, minimum weight rises to 2350 lbs. · T2-T4 Spec Lines remove wheelbase requirement, replace with Required Restrictor specification. · T4 Mazda RX-8 rear spring opens to any 400lb, was specific part numbers only. · T2 and T3 Nissan 370Z brake rotors enlarged: front 320x28 to 355x32mm, rear 320x16 to 350x20mm vented. · GT1, GT2, GT3, GTL, GTX rear spoiler maximum surface area limit of 295.0 square inches removed. · GT1/GT2/GT3/GTL/GTX Direct Injection now permitted if OE, using only OE pump, hoses, injectors. · GT3 Toyota FA24D engine classified: 2387cc DOHC, 2195 lbs, 32mm SIR, direct injection permitted. · GT2/3 Nissan, Mazda, Mitsubishi 4G93, QR25DE/DD, QE25DE/DD Direct Injection now permitted per 9.1.2.F.7.5.E. · GT3 Nissan QR25DE/DD spec line edit; text unreadable due to formatting corruption. · T2, T3, T4 battery replacement wording simplified; OEM weight tolerance requirement removed. · T4 Mazda MX-5 Miata/Club (16-18) and (19-21) permitted to replace 3rd and 4th gears with specific parts. · T4 now permits C-Spec cars to compete alongside B-Spec cars. · T2-T4 spec lines for 46 cars expire 12/31/24; appeal required to continue. · GT3 Mazda RX7 12A, 13B Bridgeport, 13B Peripheral Port: disenfranchised GT2 adds 75 lbs. · GT3 Mazda BP4W turbocharged OEM engine weight reduced from 2060 to 1960 lbs. · GT3 Mazda 13B peripheral port weight reduced to 2100 lbs. · GT3 adds Toyota GR 86 (DR86) 2021–2024, 2-door RWD, 101.3 in wheelbase. · GT3 Toyota 3S bore increases to 86.0mm, stroke decreases to 86.0mm. · T4 Mazda MX-5 ND1 minimum weight increases 50 lbs to 2700; suspension springs now allow up to 500 lb front, 300 lb rear. · T4 BRZ/FRS/86 spring allowance clarified: 225 lb front and 300 lb rear springs permitted; non-OEM LSD allowed with +50 lbs penalty. · T4 Acura TSX 2004-2008 now allows header. · T3 Nissan 370Z model years expanded to include NISMO Edition through 2022. · GT3 Toyota 3S DOHC engine classified at 1998 cc, 1960 lbs minimum weight, unrestricted fuel induction. · GT3 2.0L SIR cars lose 32mm unrestricted option, now require restrictor at 2195lbs minimum. · GTL spec lines moved to contiguous position with GT2 and GT3; GTA category and spec lines renumbered and moved behind GTL. · GT3-TCR Audi RS3 LMS, Honda Civic Type R, Hyundai i30 N, VW Golf GTi must use 200 tread wear tires only. · GT3 Honda B20 engine newly classified for use in CRX, 1973cc displacement, aluminum head, DOHC. · T4 Mercedes Benz CLK 320 Coupe model years expand to 2000-2007, C320 Sedan added. · GT3 cars using 15" American Racer 23.5-10.0-15 bias ply tires avoid weight penalty. · T3 Mazda RX-8 removes transmission/final drive pairing requirement; T4 removes same requirement, adds Mazdaspeed radiator and coil spring kit. · T3 BMW 320i (14-15) gains aftermarket intercooler permission; T4 loses it. · T3 Pontiac Solstice GXP minimum ride height set to 3 inches. · T4 Mini Cooper S R53 loses 50 lbs, to 2700 for both 02-04 and 05-06 model years. · T4 Mini Cooper S all years now run 17-inch wheels, up from 16, with wider rims to 8 inches. · T4 Volkswagen Rabbit 2.5 (06-09) consolidates 06-07 and 08-09 models; Integrated Engineering intake allowed with 25lb penalty. · T4 Audi A4 2.8 V6 wheels grow to 17x8, tyres to 245, springs now 800lb with 32mm sway bars. · Fields Cardinal V8 classified in GT1 with Ford V8 engine, 4.9L displacement, 2100 lbs minimum weight. · Acura TSX 2004-2008 newly classified in T4 at 3000 lbs minimum weight with 2354cc engine. · T4 Mustang rear sway bar increases from 22mm to 28mm permitted. · T3 BMW 320I now permitted to use aftermarket intercooler. · T4 Mazda MX-5 ND2 (19-21) classified: 1998cc, 2309mm wheelbase, 225 max tires, 2800 lbs. · T2/T3 Mustang GT 5.0L and V6 (11-14) may remove upper grille fog lights, replace with mesh or screen. · T4 Mazda MX-5 Club Model 06-15 Mazda Motorsports LSD part number corrected from 32655 to 0000-02-5564. · GT3 Nissan VG30 engine removed from class entirely. · GT3 normally aspirated cars may use intake chokes instead of SIRs, fitted to each carburetor barrel, same size as required SIR. · GT3 2.0L 4-valve non-turbo engines may run unrestricted at 2060 lbs instead of with a choke restriction. · T4 Honda Civic Si 06-11 now permits 32mm sway bars front and rear and 700 pound springs. · T5 class added as regional-only; T5 tyres maximum width 225, minimum aspect ratio 45. · T2-T5 Touring front and rear suspension maximum negative camber changed to 3.5 degrees. · GT3 Mazda BP4W Turbocharged OEM engine added at 2060 lbs with 34mm TIR and IHI RHF5 VJ35 turbocharger. · GT2 TA2 and GTA throttle body part numbers updated to GM 90mm electronic #12570790 or Edelbrock 90mm mechanical #33869 or #3870. · GT3 Nissan SR20VET turbo changes to GT2860RS and allows open ECU instead of OEM stock. · T4 Ford Mustang V6 (05-10) wheels widen to 18x9, front brakes grow to 314mm vented, weight drops to 3275 lbs. · T4 Mazda MX-5 Club (06-15) minimum weight drops 25 lbs to 2600; Mazda LSD #32655 now permitted without penalty. · GT3 adds 84-87 Civic 3dr FWD, hood bulge allowed, no openings. · GT3 Turbo maximum displacement increases from 1800 cc to 1850 cc. · T3 Subaru BRZ 2022- minimum weight up to 2975 lbs; spring rate to 1000 F/R, brake parts allowed without penalty. · GT taillights may now be original style or a panel graphic with functioning red LED brake lamps; wording change only. · GT3 Nissan SR20VET Limited Prep-Turbocharged OEM engine classified, 1998cc DOHC with Garrett GT2560LS turbo, 2060 lbs. · T4 Mazda3 04-09 now permits Corksport balance shaft delete kit GEN-6-504-10. · GT3 Fiat 124 Spider model name corrected from Pininfarina to Pininfarina Spider. · GT3 Fiat 124 Spider Pininfarina reclassified by model year, body style, drivetrain, and wheelbase. · T4 Hyundai Tiburon V-6 wheel width increases from 7 to 8 inches at 17-inch diameter. · GT3 cars can use up to 18" wheels with 12.0" tire cross section and 26.0" diameter at 5% weight penalty, down from 8%. · T4 Mazda3 i 2.0L added as spec line with 1999cc displacement and 2425 lbs minimum weight. · T2-T4 Touring cars with alternative springs may use performance top hats with spherical bearings on shocks and struts. · GT3-TCR: Audi RS3 LMS SEQ power to 90%, weight to 3177 lbs; RS3 LMS DSG power to 90%; Honda Civic Type R power to 90%, weight to 3210 lbs; Hyundai i30N power to 90%, weight to 3254 lbs; VW Golf GTI SEQ power to 90%, weight to 3177 lbs; Gol… · T2-T4 cars model year 2018+ may use non-OEM ECU with 75 lb weight penalty via spec line adjustment. · T4 Nissan Sentra SE-R Spec V 02-06 now permits balance shaft removal kit OQR25-NOBAL. · T4 BMW 323 (98-00) wheelbase increases to 2725 mm, final drive ratio changes to 3.07. · T4 Mazda RX-8 04-12 gains Eibach spring alternatives to Mazda Motorsports springs front and rear. · T4 Mazda3 04-09 tire size increases from 235 to 245. · T4 Ford Mustang V6 05-10 shock part numbers corrected to 8741-1494SPORT front and 8241-1240SPORT rear. · T4 Scion FR-S and Subaru BRZ Solo Spec Coupes updated to 2020 specifications Rev 7/20. · T4 2016–18 Mazda MX-5 Miata/Club gains 100 lbs. for approved suspension package with specific springs. · GT3 Ginetta G40 classified with Mazda MZR 1999cc at 2060 lbs or Ford Duratec 2260cc at 2195 lbs. · GT3 Mazda MZR DOHC 1999cc classified with 2195 lbs minimum weight, unrestricted fuel induction. · Volvo S60 2000-2009 classified in GT3. · GT3 2.0L 4V engines now unrestricted at 2195 lbs minimum weight across all makes. · GT3 wing wording corrected: single element airfoil scaled changed to up to maximum chord 10.75 inches. · T2-T4 grill openings may remove non-metallic webbed false sections; 16 square inch limit removed. · T3 Spec Lines Subaru BRZ TS (13-21) added to class specification wording. · GT3 adds Fiat Spider 2000, Years 79-81, RWD, 89.76" wheelbase. · GT3 adds Fiat X-19, years 72-89. · T4 Mazda MX-5 Club 06-15 allows non-OEM LSD with +50 lbs penalty; removes stock transmission and differential requirements. · T4 2005-2010 Ford Mustang V6 now specifies Koni damper part numbers 8741.1494 front and 8741.1240 rear. · T2-T4 clarified: grill opening area may increase max 16 sq in for radiator cooling only, retaining factory mesh shape. · T4 BMW 323 98-00 minimum weight drops to 3250 lbs, 50mm restrictor removed. · T4 Honda Civic Si consolidates 12-13 and 14-15 into single 12-15 spec line with updated suspension allowances. · T2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted. · T2, T3, T4 clarify that spec lines listing permitted or allowed parts are alternatives to category rules, not replacements. · T4 Acura RSX/RSX Type-S 02-06 removes requirement that original wheels must remain stock. · T4 Chevrolet Camaro V-6 (96-02) removes requirement that shock/struts, mounts, and transmission differential remain stock. · GT3 Fun Cup Beetle Sealed weight reduced 210 lbs, to 1850. · GT3-TCR class added: Audi RS3 LMS, Honda Civic Type R, Hyundai i30N, VW Golf GTI at 3100–3200 lbs with 200 tread wear tires. · Nissan Sentra SE-R Spec V (2007–2012) newly classified in T4 at 3000 lbs minimum weight. · T4 Mazda RX-8 04-12 allows alternate sway bars max 32mm front, 19mm rear; removes 60mm restrictor requirement. · T4 BMW 320i (14-15) now allows GFB T9357 aluminum diverter valve. · T4 Honda Civic FWD gets wider 8-inch wheels, 245 tyres max, and sway bar allowances to 29mm front, 22mm rear. · T4 multiple cars: Volkswagen Rabbit 2.5 (08-09) to 2675 lbs; Mazda MX-5/Club (06-15) to 2625 lbs; RX-8 to 3125 lbs; Honda/Acura/Chevy/Mazda wheel widths 7 to 8 inches. · GT3 Ford Cortina GT 1964-1968 newly classified for competition. · T4 Volkswagen Passat, Jetta 1.8T adds 2014 model year to eligible years. · GT3 Fun Cup Beetle EVO3 classified with 1984 cc sealed SOHC engine, 2060 lbs minimum weight. · GTA part numbers updated: 0-80541-1 to 0-80541-2 in two sections and 6010 to 6014X in TA2 Appendix. · GT3 now permits current FP spec line cars to compete while maintaining their full FP rule set. · T4 BMW 320i 14-15 part number corrected from 20121.140 to E10-20-031-01-22. · T3 Honda Civic Type-R 2020+ allows brake rotor 45251-TGH-A01 with 25 lb penalty. · GT3 Mazda MZR 2.0L fuel induction restrictor increases from 31 to 32 mm. · GT3 Mazda Renesis and 13B Bridgeport choke reduced from 44mm to 42mm. · T4 Mini Cooper S (02-04, 05-06) suspension/wheel rules simplified; (07-13) gear ratios changed to 3.31, 2.13, 1.48, 1.14, 0.95, 0.82, final drive to 3.65, brakes to 280 mm. · T4 Ford Mustang V6 05-10 now allows cold air intake. · T2-T4 clutch disc and pressure plate must be at least 95% of factory OEM weight. · T4 Ford Mustang V6 05-10 wheels increase from 17 to 18 inches. · Toyota Supra 2020- newly classified in T2 at 3450 lbs minimum weight with 295 tire and 19-inch wheels. · T4 Mazda MX-5 durability rule now applies to T2-T4 instead of T2-T3 only. · T4 Chevrolet Sonic (2011-) spec clarified: 28mm TIR restrictor placement, PCV plug requirement, and allowed suspension parts listed. · T4 Mazda MX-5 06-15 removes front and rear end links from suspension package spec. · T4 BMW Z4 2.5L (03-05) minimum weight reduced from 3100 to 3050 lbs. · T4 2016+ Mazda MX-5 Miata gains allowance for 29mm front and 16mm rear sway bars. · T4 Scion FR-S, Subaru BRZ, and Toyota 86 replace Eibach part 4.10582.880 with 82105.320, 4.10582 and SPC 67660. · T4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.45 or 3.55 ratio at +25 lb penalty. · BMW M2 CS Cup 2020+ classified in T2 at 3625 lbs with 2979cc engine, 10.5x18 wheels, 295 tires. · T3 and T4 Mazda MX-5 06-15 now allow Mazda Transmission kit part # 0000-02-5700. · T4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.55 final drive, adds 25 lb penalty. · T3 and T4 FR-S, 86, and BRZ year ranges capped: T3 at 2021, T4 at 2017-2021. · GT3 Mazda MZR and MZR/L5-VE fuel induction sizing changes from 31 to 32. · GT3 Honda Prelude 1992-1997 classified, 2dr FWD, 104 inch wheelbase. · T3 Alfa Romeo 4C Launch Edition now allowed in Spec Lines. · GT1, GT2, GT3, GTL, GTX now permit turbocharging/supercharging if listed on spec line. · T4 Scion FRS and Subaru BRZ Solo Spec Coupe final drive ratio changed from 4.30 to 4.10. · GT3 Mazda 12A Peripheral Port added to rule set, 2300 cc, 2292 lbs. · TA2 Gurney flap wording clarified: terminology standardized to 'Gurney flap', height limits and thickness specifications remain 0.50 inch / 0.625 inch or 0.375 inch / 0.0625 inch depending on configuration. · STO rear wing wording clarified: 'wicker' changed to 'Gurney flap' in maximum chord and mounting height rules. · GT classes clarify Gurney flap wording, replacing wickerbill/tab terminology with flap; specifications unchanged. · GT3 4v SIR 4-cylinder engines across multiple brands increase fuel induction from 31 to 32. · GT3 and STU add Borg-Warner EFR6258 to approved turbocharger list. · T4 Mazda RX-8 04-12 now allows OE rear spoiler #F151-V4-920F and OE front air dam #F151-V4-900f-BB. · T4 2006-2015 Mazda MX-5 Club Model now allows non-stock wheels; transmission, differential, LSD remain stock. · Cannot read: letter references external document #27663 not provided. · GT3 Nissan KA24E loses permission to use 32mm chokes at 2280 lbs for 2011-2012 only. · 2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine and Eibach PN# 2563.140 springs allowed. · T4 06-15 Mazda MX-5 now allows header part numbers 0000-06-5407 or 0000-06-5407-NC. · T3 BMW Z3 M & Coupe 1998-1999 weight reduced from 3350 to 3150 lbs. · GT3 Mazda MZR L5-VE gets 31mm SIR restrictor, weight up from 1950 to 2195 lbs, direct injection banned. · T4 Honda Civic Si 12-13 and 14-15 now allow H&R and HPD springs up to 700 pounds with 47mm restrictor. · T4 Ford Mustang V6 05-10 springs now permitted max 500 lbs front and 400 lbs rear. · GT1, GT2, GT3, GTL, GTX may omit windshield clips if factory glass is bonded per original specifications. · T4 Ford Mustang V6 05-10 allowed aluminum driveshaft, any LSD, and Ford brake kit M-2300-D. · Pontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18 x 9.5 inches, Sky weight drops to 3200 lbs. · Mazda RX-8 Base/R3/Sport/GT (04-12) classified in T3 effective 2020-02-01. · T4 Mazda3 14-18 gains permitted modifications: springs to 800/1000 lbs, 15 lb wheels, cold air intake, camber plates, 25mm rear bar, mirrors, CorkSport arms, header, specific calipers and rotor. · T4 allows aftermarket OEM coolant expansion tanks with no other functional purpose. · T4 Mazda MX-5 Club Model 06-15 now allows aftermarket power steering reservoir. · T4 Subaru BRZ and Scion FR-S allowed factory installed wings. · T4 now permitted to use any OEM diameter clutch disc and pressure plate, previously T2-T3 only. · Chevrolet Sonic 2011+ added to T4 at 2800 lbs with 1364 cc engine and 225 max tire size. · T4 Mazda MX-5/Miata 1999-2005 minimum weight reduced 50 lbs to 2400. · Factory Five Type 65 Coupe R with Ford 302/351 or 5.0/5.2L NA added to GTX-MISC at 2600 lbs. · GT3 Mazda 13B Bridgeport restrictor reduced from 44mm to 42mm. · GT3 Alfa Romeo 4C classified with 1742cc engine, 33mm TIR restrictor, 2325 lbs minimum weight. · GT3 Mazda MZR/L5-VE gets unrestricted induction, drops 245 lbs to 1950, limited to GT2 prep. · GT3 Honda K20C1 turbocharged engine added with 33 mm TIR restrictor, 2350 lbs minimum weight. · GT3 wing end plates change from 11.00 by 4.00 inches rectangle to maximum 64 square inches. · T2 requires onboard fire system; T3 and T4 may have one per GCR 9.3. · T3 Ford Mustang EcoBoost 2015- gains three transmission gear ratio options. · T4 BRZ, FR-S, and 86 maximum tire size reduced from 245 to 225. · T4 Mazda MX-5 Club Model 06-15 minimum weight cut from 2625 to 2550 lbs. · Mazda RX-8 Base/R3 (04-12) reclassified in T3 and T4 to include Sport and GT variants. · Toyota 86 GT (2017-) added to T3 and T4 Spec Line. · GT3 Nissan adds SR16VE engine, 1596cc, 1690 lbs, unrestricted induction. · GT3 Mazda 12A Bridgeport gains optional 42mm choke at 2010 lbs minimum weight. · T2-T4 spare tire/wheel rules clarified: removable covers can be removed with hardware and bracketry. · T4 Mazda MX-5 Club (06-15) gains suspension package with 100 lbs weight increase, allows RX8 hubs and SM5 suspension, permits non-OEM LSD with 50 lbs penalty. · T4 Toyota MR-2 Spyder 16V DOHC years corrected from 01-05 to 00-07. · T4 Mazda Protégé ES 2000 now allows piggyback ECU tuning device; OBD2 requirement waived. · T4 Mazda MX5 Club Model 06-15 allows suspension package with 100 lbs weight increase including helper springs. · GTX tube frame cars gain fuel injection with 90mm maximum throttle body size. · Ligier JS2 R classified in GTX, no performance parameters specified in filing. · GT3 Mazda 13B and Renesis engines reclassified with new weight specs ranging 2080–2350 lbs. · GT1 and GT2/GT3/LITE ride height requirements removed from GCR sections 9.1.2.D.5.a.1 and 9.1.2.F.7.b. · T4 BMW 323 (98-00) newly classified at 3450 lbs with 50mm flat plate restrictor and M52TUB25 engine required. · GT3 13B and Renesis rotaries gain 200 lbs minimum weight; 13B Peripheral Port to 2400, Bridge Port to 2400, Renesis Peripheral Port to 2450, Bridge Port to 2450. · GT3 adds Mitsubishi 4G69 SOHC 2378cc engine, 2195 lbs minimum weight, 31mm SIR. · T4 Mazda MX-5 Club (06-15) and (2016-), T3 MX-5 Cup and Miata (2016-) hardtop rules clarified; wording changes to permitted parts and specifications. · T2, T3, T4 now allow any thermostat serving only OE intent, previously restricted. · T3 and T4 Mazda MX-5 Miata eligibility capped at 2018 model year, effective 2019-03-01. · T4 Honda Civic Si 2012-2015 permitted sway bars increased to 32mm front and rear. · GTX FIA GT3: Audi R8 40mm restrictor 2900 lbs, BMW Z4 70mm 2800 lbs, Ferrari 488 35mm restrictor 3025 lbs classified. · T4 Ford Fiesta ST years corrected to 14-; T4 Fiat 124/Abarth Edition years added 16-18; battery rule clarified. · T4 Fiat 124 Abarth Edition restrictor changes from 29mm flat plate to 30mm TIR. · T1-T3 spec cars receive clarifications on permitted modifications, documentation requirements, and rule conformance; no performance changes. · T2-T4 subframe bushings may now be replaced with non-spherical bushings of any material. · Scion FR-S and Subaru BRZ 13-16 Solo Spec Coupes added to T4, both 1998cc, 2570 lbs, 225/45/17 tires.showhide
T4 Ford Mustang V6 (05-14) #37516wordingneutralT4 Ford Mustang V6 (05-14) final drive set to 3.45, GT/CS front bumper cover permitted with front fascia.
T4 Request to Classify Club Spec in Appropriate Touring Classes #37523cars addedneutralFord SCCA Club Spec Mustang classified T3 at 3350 lbs with driver; Mazda SCCA Club Spec MX-5 classified T4 at 2500 lbs with driver.
GT3 Correct language regarding OEM Areo Devices #37137wordingneutralTA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof requirement.
GT3 VW Funcap weight #37217weightfasterGT3 VW Fun Cup Beetle Sealed exempt from 150 lbs consolidation add-on weight.
T4 Remove spec lines that have expired #37269removedneutralT2, T3, T4 remove nine, nine, and thirty-six expired spec lines respectively, effective 2025-01-01.
GT3 Pontiac Weight and Chassis Adjustment Request #36938weight -150 lbsfasterGT3 Pontiac LE5 Ecotech minimum weight drops 150 lbs to 2195.
T4 Redundant Verbiage Regarding Mustang Spec Lines for Driveshaft #36484wordingneutralT2 and T3 Mustang spec lines remove redundant driveshaft alternate/aluminum allowance wording.
T4 R53 Mini Cooper S Weight Reduction Request #36612enginefasterT4 Mini Cooper S R53 now allows Alta 15% Pulley #AMPENG20X.
T4 Allowable Wheel Offset #36855wordingneutralT4 removes restriction on aftermarket wheel weight minimum of 15 lbs.
T4 Fuel Emissions Components #37076wordingneutralT2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors.
T4 2019-2024 Mazda 3 for T4 #37077cars addedneutralMazda 3 (19-24) newly classified in T4 at 2850 lbs with 17×8 wheels and 245 tires.
T4 fix brake wording #37129wordingneutralT2, T3, T4 brake component wording clarified: 2-piece rotors allowed in T2 within 5% OE diameter, T3 within 2% OEM diameter.
T4 Evaporative emissions systems #37130wordingneutralT2, T3, T4 fuel cell cars may remove charcoal canisters, emissions valves, and sensors.
T4 Allow Spec MX5 upgrade kit for 2009-11 RX8 S2 Transmision #37140wordingneutralT3 and T4 Mazda RX-8 and MX-5 permit transmission kit #0000-02-5700.
T4 Move Spec Boxster to T4 #37158cars addedneutralPorsche Spec Boxster moves to T4, minimum weight 2750 lbs, requires 3 Super Tour events before Runoffs eligibility.
T4 3.7 Mustangs to T4 #37188cars addedneutralFord Mustang V6 (05-14) newly classified to T4 with 50mm restrictor, 3400 lbs minimum weight.
T4 BMW 320i Spec Line #37204wordingneutralT4 BMW 320i 14-15 Spec Line expires 12/31/24 removed; Turner Motorsports intercooler #024703TMS02 allowed.
T4 MX5 2006-2015 NC Help #37221otherunclearUnable to summarize: rule changes specified in letter #37281, not provided.
T4 Classification for a 2005 Cadillac CTS 3.6 liter 6 speed manual #37224cars addedneutralCadillac CTS 02-07 3.6L classified in T3.
T4 Civic SI in T4 #37248weight -50 lbsfasterT4 Honda Civic Si 06-11 minimum weight drops 50 lbs to 2900, restrictor clarified.
T4 2006-2015 T4 NC Mx5 spec line #37278wordingneutralT4 NC MX-5 06-15 removes SM5 suspension allowance, clarifies Mazda Motorsports LSD part number, adds weight penalty for other LSDs.
T4 ND MX-5 wheel allowance #37279tyres & wheelsunclearT4 Mazda MX-5 Miata/Club (16-18) wheel size changes to 17 x 7.5 inches.
T4 T4 BOP #37281weight +75 lbsslowerT4 Mazda RX-8 gets 59mm restrictor and 3200 lbs; MX-5 Club drops to 2550 lbs.
T4 Allow 7.5 #37286tyres & wheelsneutralT4 Mazda MX5 Miata/Club/RF 19-24 wheel size changes to 17 x 7.5.
GT3 GCR GT3 Disfranchised GT2 #36291weight -75 lbsfasterGT3 Mazda 13B Bridgeport and Peripheral Port both drop to 2275 lbs minimum weight.
GT3 GT3 Mazda12A PP Correction #37058weight -200 lbsfasterGT3 Mazda 12A peripheral port minimum weight reduced to 2100 lbs.
T4 Bop Request 06-11 Honda Civic Si #37013wordingneutralT4 Honda Civic Si 06-11 permitted to use LSD per category rules.
GT3 2024 Mazda 3 TC request for GT3 #36517cars addedneutralGT3 Mazda 3TC classified in TCR with 2950 lbs minimum weight, effective 11/1/2024.
GT3 Adding Datsun B110 to List of Approved Cars #36198cars addedneutralGT3 adds Datsun 1200 B110 (70–73), 90.6 in wheelbase, engine per GT3 spec or alternate Nissan request.
GT3 Honda Civic Type R TCR Weight Reduction Request #36550weightfasterGT3-TCR Honda Civic Type R, Audi RS3 LMS, Hyundai I30N, Volkswagen GTI weights adjusted; Hyundai down 100 lbs to 3154, VW down 100 lbs to 3077.
T4 T4 Camaro V6 weight reduction #36232weightfasterT4 Chevrolet Camaro V-6 (96-02) weight reduced from 3250 lbs to 3150 lbs.
T4 BOP adjustment for ND MX5s #36345weight -50 lbsfasterT4 Mazda MX-5 Miata/Club 16-18 drops 50 lbs to 2650; 19-24 RF drops 50 lbs to 2750.
GT3 Correct missed Disenfranchised weight reduction #36237weightfasterGT3 Pontiac Sunfire GT weight reduction corrected from 150 lbs to 75 lbs.
GT3 errors & omissions on GT3 Mazda MZR spec lines #36241enginefasterGT3 Mazda MZR removes second DOHC option, fuel induction now unrestricted.
T4 Mustang T2/T3 #35877wordingunclearFord Mustang GT 5.0L and V6 now permit Track/Performance Package parts in T2 and T3.
T4 Homologation of car to T4 #36030cars addedneutralMercedes C300 4Matic 2008-2011 homologated to T4 at 3,725 lbs with 18x8.5 wheels, 245 max tires, 3.27 final drive.
T4 T2-T4 Driveshaft Mistake...? #36050weightfasterT2-T4 Ford Mustangs: remove 25 lbs penalty for non-OEM driveshaft, clarify alternate driveshaft allowances.
T4 MINI Cooper S Spec Lines Corrections. #36086wordingneutralT4 Mini Cooper S (02-04) deleted; (05-06) model year corrected to R53; (07-13) R56 simplified specs; (2014-2023) added with spring rates.
T4 Allow Removal of Sound Tubes #36130inductionfasterT4 OEM intake chambers, resonators and acoustic devices may be removed if ports sealed and before restrictor.
T4 B8/8.5 Audi S4 T3 and T2 #36195cars addedneutralAudi S4 (2000-2002) moves to T3 with 3400 lbs minimum weight, 38mm turbo inlet restrictor required.
GT3 GT3 +1mm SIR add 175lbs. In #36098weightslowerGT3 cars may run +1mm SIR above spec with 175 lb weight penalty added.
GT3 Revised GT3 Built Turbocharged chart #36100inductionslowerGT3 turbocharged 1401-1850cc four-valve engine with 35mm restrictor reduced to 34mm, weight to 2250 lbs.
T4 Allow OEM Front Spoiler 06-08 Miata in T4 #35941aerofasterT4 Mazda MX-5 Club 06-15 now permits OEM front spoiler NF51-V4-900F.
T4 T4 Mustang Weight Reduction In T4 Spec #36051weight -50 lbsfasterT4 Ford Mustang V6 (05-10) weight reduced 50 lbs to 3225.
T4 R53 Mini Cooper S spec line request In #36056otherfasterT4 Mini Cooper S 02-04 and 05-06 now allow Milltek exhaust manifold #SSXM459 and 25mm rear sway bar.
GT3 Request for Spec Line 1010 Reconsideration #35009weight +300 lbsslowerGT2-ST Acura NSX minimum weight raised to 3000 lbs, restrictor increased to 45mm TIR.
GT3 Mazda MZR Engines #35753aeroneutralGT3 Ford Duratech now allows hood bulge with no openings.
GT3 Disenfranchised GT2 Acura RSX to Run GT3 #35773weightslowerGT3 Acura K20A RSX body disenfranchised from GT2 adds 75 lbs weight penalty.
GT3 Toyota 4Y Engine Request #35885cars addedneutralGT3 Toyota 4Y engine classified at 2030 lbs with unrestricted fuel induction.
GT3 GT3 spec lines clean-up #36008wordingneutralGT3 Toyota model designation changes from DR86 to GR86.
GT3 GT3 Honda spec line clean-up x 2 #36009wordingneutralGT3 Honda spec lines change engine family designation from bore/displacement to K20C1 and K24 model numbers.
GT3 GT3 Mazda spec line clean-up x2 #36010wordingneutralGT3 Mazda spec line numbering changed from 4 to Model, unrestricted to 323, and 2195 to 626.
T4 Allow T4 and T3 RX8 to Disable/Remove Factory Oil Inj. #35761engineunclearT3 and T4 Mazda RX-8 may remove or disable factory oil injection system.
T4 2023 ND2 Miata Classification and Allowances #35837weightslowerT4 Mazda MX5 Miata/Club/RF year range extended to 2024, suspension package permitted with 100 lbs weight increase.
T4 Errors and Omissions for 06-09 VW Rabbit Rotor #35851suspension & brakesfasterT4 Volkswagen Rabbit 2.5 (06-09) front brakes increase from 228 to 288 vented disc.
T4 Driveshafts #35916weightslowerT2, T3, T4 driveshafts may use alternative materials or one-piece units; non-OEM adds 25 lbs.
T4 GCR ERROR - letter not properly applied to GCR #35999suspension & brakesfasterT4 Mazda MX-5 Miata/Club 16-18 removes differential stock requirement, allows up to 500lb front and 300lb rear springs.
T4 Corrections to T4 RX8 Spec line #35767wordingneutralT4 Mazda RX-8 allows Mazdaspeed radiator, coil spring kit, OE rear spoiler, front air dam, springs to 700 lb front/400 lb rear, oil metering pump bypass, sway bars to 32 mm front/19 mm rear.
GT3 Miata Turbo Clarification #35386weight +100 lbsslowerGT3 Miata Turbo restrictor increases to 35 mm, minimum weight rises to 2350 lbs.
T4 Allow any 400lb rear spring in the RX8 #35433suspension & brakesneutralT4 Mazda RX-8 rear spring opens to any 400lb, was specific part numbers only.
T4 370Z Brake Rotor Size Correction #35487suspension & brakesneutralT2 and T3 Nissan 370Z brake rotors enlarged: front 320x28 to 355x32mm, rear 320x16 to 350x20mm vented.
GT3 Rear Blade Spoiler Clarification #35261aerofasterGT1, GT2, GT3, GTL, GTX rear spoiler maximum surface area limit of 295.0 square inches removed.
GT3 GT Direct Injection allowance and rules #35437enginefasterGT1/GT2/GT3/GTL/GTX Direct Injection now permitted if OE, using only OE pump, hoses, injectors.
GT3 Request to Include Toyota FA24D Engine for use in GT3 #35199cars addedneutralGT3 Toyota FA24D engine classified: 2387cc DOHC, 2195 lbs, 32mm SIR, direct injection permitted.
GT3 GT2/3 remove Direction Injection not allowed in Spec line notes #35439inductionfasterGT2/3 Nissan, Mazda, Mitsubishi 4G93, QR25DE/DD, QE25DE/DD Direct Injection now permitted per 9.1.2.F.7.5.E.
GT3 Edit GT3 Nissan QR25DE/DD spec line #35442wordingunclearGT3 Nissan QR25DE/DD spec line edit; text unreadable due to formatting corruption.
T4 More Car Lightening Stuff #35319weightfasterT2, T3, T4 battery replacement wording simplified; OEM weight tolerance requirement removed.
T4 ND Missed Items #35352wordingneutralT4 Mazda MX-5 Miata/Club (16-18) and (19-21) permitted to replace 3rd and 4th gears with specific parts.
T4 Inclusion of B-C spec cars in T4 #35374cars addedneutralT4 now permits C-Spec cars to compete alongside B-Spec cars.
T4 T2-T4 Set expiration dates on spec lines #35378wordingneutralT2-T4 spec lines for 46 cars expire 12/31/24; appeal required to continue.
GT3 Turbo Help #35042weight -100 lbsfasterGT3 Mazda BP4W turbocharged OEM engine weight reduced from 2060 to 1960 lbs.
GT3 Competition Adjustment Request for 13B Peripheral Port #35100weight -100 lbsfasterGT3 Mazda 13B peripheral port weight reduced to 2100 lbs.
GT3 Request to Include Toyota GR 86 in GT3 #35197cars addedneutralGT3 adds Toyota GR 86 (DR86) 2021–2024, 2-door RWD, 101.3 in wheelbase.
GT3 Fastrack Toyota 3S Correction #35258engineunclearGT3 Toyota 3S bore increases to 86.0mm, stroke decreases to 86.0mm.
T4 Mazda MX-5 ND1 Spec Line Request #34232weight +50 lbsslowerT4 Mazda MX-5 ND1 minimum weight increases 50 lbs to 2700; suspension springs now allow up to 500 lb front, 300 lb rear.
T4 BRZ/FRS/86 Spring Allowance #35038wordingneutralT4 BRZ/FRS/86 spring allowance clarified: 225 lb front and 300 lb rear springs permitted; non-OEM LSD allowed with +50 lbs penalty.
T4 TSX Allowance #35219aerofasterT4 Acura TSX 2004-2008 now allows header.
T4 Requested Update of Model Years of 370Z #35231wordingneutralT3 Nissan 370Z model years expanded to include NISMO Edition through 2022.
GT3 Toyota Engine Classification Request #35019engineneutralGT3 Toyota 3S DOHC engine classified at 1998 cc, 1960 lbs minimum weight, unrestricted fuel induction.
GT3 GT3 2.0L SIR & weight #35171inductionslowerGT3 2.0L SIR cars lose 32mm unrestricted option, now require restrictor at 2195lbs minimum.
GT3 Errors in GTCS Headings and Use of the Terms Category and ClassChange existing GTL and GTA Rules #34453wordingneutralGTL spec lines moved to contiguous position with GT2 and GT3; GTA category and spec lines renumbered and moved behind GTL.
GT3 GT3 TCR 200 TW tires #34993tyres & wheelsslowerGT3-TCR Audi RS3 LMS, Honda Civic Type R, Hyundai i30 N, VW Golf GTi must use 200 tread wear tires only.
GT3 Classify Honda B20 engine in GT3 CRX #34781cars addedneutralGT3 Honda B20 engine newly classified for use in CRX, 1973cc displacement, aluminum head, DOHC.
T4 Inclusion of similar car. (CLK 320) #34626cars addedneutralT4 Mercedes Benz CLK 320 Coupe model years expand to 2000-2007, C320 Sedan added.
GT3 Addendum to letter 33913, GT3 DOT tires. #34627tyres & wheelsfasterGT3 cars using 15" American Racer 23.5-10.0-15 bias ply tires avoid weight penalty.
T4 Rules Clarification for Mazda RX8 Spec Line #34395wordingneutralT3 Mazda RX-8 removes transmission/final drive pairing requirement; T4 removes same requirement, adds Mazdaspeed radiator and coil spring kit.
T4 rule book corrections #34437otherfasterT3 BMW 320i (14-15) gains aftermarket intercooler permission; T4 loses it.
T4 Ride Height Correction for the T3 Solstice. #34615wordingneutralT3 Pontiac Solstice GXP minimum ride height set to 3 inches.
T4 2002-2006 Mini Cooper S R53 Spec Line Request #34336weight -50 lbsfasterT4 Mini Cooper S R53 loses 50 lbs, to 2700 for both 02-04 and 05-06 model years.
T4 05-06 Mini Wheel Weight #34112tyres & wheelsfasterT4 Mini Cooper S all years now run 17-inch wheels, up from 16, with wider rims to 8 inches.
T4 96-01 Audi a4 2.8 Spring Rate #34217suspension & brakesfasterT4 Audi A4 2.8 V6 wheels grow to 17x8, tyres to 245, springs now 800lb with 32mm sway bars.
GT3 Please classify Fields Cardinal V8 #33784cars addedneutralFields Cardinal V8 classified in GT1 with Ford V8 engine, 4.9L displacement, 2100 lbs minimum weight.
T4 Request to Classify 2004-2008 Acura TSX in T4 #33590cars addedneutralAcura TSX 2004-2008 newly classified in T4 at 3000 lbs minimum weight with 2354cc engine.
T4 T4 Mustang Brakes/Swaybar #34036suspension & brakesfasterT4 Mustang rear sway bar increases from 22mm to 28mm permitted.
T4 BMW 320I intercooler #33762otherfasterT3 BMW 320I now permitted to use aftermarket intercooler.
T4 Mustang OEM Grill Request #33333aeroneutralT2/T3 Mustang GT 5.0L and V6 (11-14) may remove upper grille fog lights, replace with mesh or screen.
T4 Mazda OEM LSD was letter 32655 typo #33666wordingneutralT4 Mazda MX-5 Club Model 06-15 Mazda Motorsports LSD part number corrected from 32655 to 0000-02-5564.
GT3 Remove Nissan VG30 engine from GT3 #33609removedneutralGT3 Nissan VG30 engine removed from class entirely.
GT3 GT3 Choke option effective 1-01-2023 #33669inductionneutralGT3 normally aspirated cars may use intake chokes instead of SIRs, fitted to each carburetor barrel, same size as required SIR.
GT3 GT3 2.0L choke/weight option #33670inductionfasterGT3 2.0L 4-valve non-turbo engines may run unrestricted at 2060 lbs instead of with a choke restriction.
T4 Allowable Springs and Sway Bars for 06-11 Civic si Spec Line #33294suspension & brakesfasterT4 Honda Civic Si 06-11 now permits 32mm sway bars front and rear and 700 pound springs.
T4 Touring (T2-T5) Category #33617cars addedneutralT5 class added as regional-only; T5 tyres maximum width 225, minimum aspect ratio 45.
T4 ENO 9.1.9.2.D.1.e.1.a. #33651suspension & brakesneutralT2-T5 Touring front and rear suspension maximum negative camber changed to 3.5 degrees.
GT3 Turbocharged Engine Rules #33145cars addedneutralGT3 Mazda BP4W Turbocharged OEM engine added at 2060 lbs with 34mm TIR and IHI RHF5 VJ35 turbocharger.
GT3 GT2 (TA2)/GTA Part Number Update #33315wordingneutralGT2 TA2 and GTA throttle body part numbers updated to GM 90mm electronic #12570790 or Edelbrock 90mm mechanical #33869 or #3870.
GT3 GT3 Nissian SR20VET unrestricted ECU change #33432enginefasterGT3 Nissan SR20VET turbo changes to GT2860RS and allows open ECU instead of OEM stock.
T4 T4 mustang #32789tyres & wheels -25 lbsfasterT4 Ford Mustang V6 (05-10) wheels widen to 18x9, front brakes grow to 314mm vented, weight drops to 3275 lbs.
T4 Mazda OEM LSD was letter 32655 #32933weight -25 lbsfasterT4 Mazda MX-5 Club (06-15) minimum weight drops 25 lbs to 2600; Mazda LSD #32655 now permitted without penalty.
GT3 GT3 Turbo Displacement Clarification #32952enginefasterGT3 Turbo maximum displacement increases from 1800 cc to 1850 cc.
T4 Another 2022 BRZ/86 T3 request #32945weight +225 lbsslowerT3 Subaru BRZ 2022- minimum weight up to 2975 lbs; spring rate to 1000 F/R, brake parts allowed without penalty.
GT3 Tail lights on all GT category race cars. #32799wordingneutralGT taillights may now be original style or a panel graphic with functioning red LED brake lamps; wording change only.
GT3 Correct Model GT3 - Fiat #32776wordingneutralGT3 Fiat 124 Spider model name corrected from Pininfarina to Pininfarina Spider.
GT3 Correct Fiat Spider Years #32149wordingneutralGT3 Fiat 124 Spider Pininfarina reclassified by model year, body style, drivetrain, and wheelbase.
T4 Request Wider Wheels for Hyundai Tiburon #32536tyres & wheelsfasterT4 Hyundai Tiburon V-6 wheel width increases from 7 to 8 inches at 17-inch diameter.
GT3 wheel size addition #32247tyres & wheelsfasterGT3 cars can use up to 18" wheels with 12.0" tire cross section and 26.0" diameter at 5% weight penalty, down from 8%.
T4 Request to Add Spec Line for 2004-2009 Mazda3 i 2.0 #32395cars addedneutralT4 Mazda3 i 2.0L added as spec line with 1999cc displacement and 2425 lbs minimum weight.
T4 Request Alternate Front & Rear Strut/Shock Top Hats #32452suspension & brakesneutralT2-T4 Touring cars with alternative springs may use performance top hats with spherical bearings on shocks and struts.
GT3 GT3 TCR Car Feedback #31677engine +2 lbsslowerGT3-TCR: Audi RS3 LMS SEQ power to 90%, weight to 3177 lbs; RS3 LMS DSG power to 90%; Honda Civic Type R power to 90%, weight to 3210 lbs; Hyundai i30N power to 90%, weight to 3254 lbs; VW Golf GTI SEQ power to 90%, weight to 3177 lbs; Gol…
T4 Request to Allow the Use of Aftermarket ECU's in Touring #31067weightslowerT2-T4 cars model year 2018+ may use non-OEM ECU with 75 lb weight penalty via spec line adjustment.
T4 Request JWT BSR Kit for 02-06 Nissan Sentra SE-R/Spec V #31685enginefasterT4 Nissan Sentra SE-R Spec V 02-06 now permits balance shaft removal kit OQR25-NOBAL.
T4 Please Confirm Touring 4 (98-00) BMW 323 is E46 generation #31972wordingunclearT4 BMW 323 (98-00) wheelbase increases to 2725 mm, final drive ratio changes to 3.07.
T4 RX-8 Spring Part Numbers (E&O) #32151suspension & brakesneutralT4 Mazda RX-8 04-12 gains Eibach spring alternatives to Mazda Motorsports springs front and rear.
T4 04-09 Mazda3 Tire Limit Clarification #32249tyres & wheelsfasterT4 Mazda3 04-09 tire size increases from 235 to 245.
T4 Shock Part Number Errors & Omissions #32252wordingneutralT4 Ford Mustang V6 05-10 shock part numbers corrected to 8741-1494SPORT front and 8241-1240SPORT rear.
T4 Update Solo Spec Coupe to latest '20 specs for Road Racing #32262wordingunclearT4 Scion FR-S and Subaru BRZ Solo Spec Coupes updated to 2020 specifications Rev 7/20.
T4 Request 2016 Mazda MX5 springs #32265suspension & brakesslowerT4 2016–18 Mazda MX-5 Miata/Club gains 100 lbs. for approved suspension package with specific springs.
GT3 Request to Classify Ginetta G40 in GT3 #31598cars addedneutralGT3 Ginetta G40 classified with Mazda MZR 1999cc at 2060 lbs or Ford Duratec 2260cc at 2195 lbs.
GT3 Volvo S60 in GT3 #31970cars addedneutralVolvo S60 2000-2009 classified in GT3.
GT3 GT3 2.0L 4V engines now unrestricted. #32190enginefasterGT3 2.0L 4V engines now unrestricted at 2195 lbs minimum weight across all makes.
GT3 TB correction to wing wording #32191wordingneutralGT3 wing wording corrected: single element airfoil scaled changed to up to maximum chord 10.75 inches.
T4 Reply to letter #31486/29879 T2-T4 Grill openings #31935aerofasterT2-T4 grill openings may remove non-metallic webbed false sections; 16 square inch limit removed.
T4 BRZ vs BRZ TS #32022wordingneutralT3 Spec Lines Subaru BRZ TS (13-21) added to class specification wording.
GT3 Request to add Fiat to GT3 CARS #31803cars addedneutralGT3 adds Fiat Spider 2000, Years 79-81, RWD, 89.76" wheelbase.
GT3 Request to add Fiat to GT3 CARS #31804cars addedneutralGT3 adds Fiat X-19, years 72-89.
T4 MX-5 Durability Detailed #31102weightslowerT4 Mazda MX-5 Club 06-15 allows non-OEM LSD with +50 lbs penalty; removes stock transmission and differential requirements.
T4 Request Allowances for 2005 - 2010 Mustang #31624suspension & brakesneutralT4 2005-2010 Ford Mustang V6 now specifies Koni damper part numbers 8741.1494 front and 8741.1240 rear.
T4 Reply to letter 29879 T2-T4 Grill Openings #31486aerofasterT2-T4 clarified: grill opening area may increase max 16 sq in for radiator cooling only, retaining factory mesh shape.
T4 Please Adjust 98-00 BMW 323 Min Weight to Reflect Current Class #31595weight -200 lbsfasterT4 BMW 323 98-00 minimum weight drops to 3250 lbs, 50mm restrictor removed.
T4 Consolidate 12-13 and 14-15 Honda Civic Si spec lines for T4 #31596wordingneutralT4 Honda Civic Si consolidates 12-13 and 14-15 into single 12-15 spec line with updated suspension allowances.
T4 Request to clarify radiator hoses #31682wordingneutralT2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted.
T4 Clarify Permitted/Allowed #31743wordingneutralT2, T3, T4 clarify that spec lines listing permitted or allowed parts are alternatives to category rules, not replacements.
T4 Correct RSX wording #31746wordingfasterT4 Acura RSX/RSX Type-S 02-06 removes requirement that original wheels must remain stock.
T4 Camaro #31751suspension & brakesfasterT4 Chevrolet Camaro V-6 (96-02) removes requirement that shock/struts, mounts, and transmission differential remain stock.
GT3 31032 correction to weight #31525weight -210 lbsfasterGT3 Fun Cup Beetle Sealed weight reduced 210 lbs, to 1850.
GT3 Add TCR cars to GT3 #31540cars addedneutralGT3-TCR class added: Audi RS3 LMS, Honda Civic Type R, Hyundai i30N, VW Golf GTI at 3100–3200 lbs with 200 tread wear tires.
T4 Nissan Sentra SE-R Spec. V #30958cars addedneutralNissan Sentra SE-R Spec V (2007–2012) newly classified in T4 at 3000 lbs minimum weight.
T4 Mazda RX-8 Spec Line Suspension Parts #31113suspension & brakesfasterT4 Mazda RX-8 04-12 allows alternate sway bars max 32mm front, 19mm rear; removes 60mm restrictor requirement.
T4 Diverter Valve Plunger Upgrade #31307wordingneutralT4 BMW 320i (14-15) now allows GFB T9357 aluminum diverter valve.
T4 Adjust Honda FWD in T4 to encourage more Drivetrain Diversity #31472tyres & wheelsfasterT4 Honda Civic FWD gets wider 8-inch wheels, 245 tyres max, and sway bar allowances to 29mm front, 22mm rear.
T4 Touring 4 BOP adjustments for 2022 #31482weight -175 lbsslowerT4 multiple cars: Volkswagen Rabbit 2.5 (08-09) to 2675 lbs; Mazda MX-5/Club (06-15) to 2625 lbs; RX-8 to 3125 lbs; Honda/Acura/Chevy/Mazda wheel widths 7 to 8 inches.
GT3 Please approve 1964-1968 Ford Cortina GT for competition in GT# #30941cars addedneutralGT3 Ford Cortina GT 1964-1968 newly classified for competition.
T4 Request to Classify 2014 VW Jetta 1.8t TSI #30436cars addedneutralT4 Volkswagen Passat, Jetta 1.8T adds 2014 model year to eligible years.
GT3 Request car classification #31032cars addedneutralGT3 Fun Cup Beetle EVO3 classified with 1984 cc sealed SOHC engine, 2060 lbs minimum weight.
GT3 Request to Update GTA Obsolete Part Numbers #30615wordingneutralGTA part numbers updated: 0-80541-1 to 0-80541-2 in two sections and 6010 to 6014X in TA2 Appendix.
GT3 Request to Permit FP cars in GT3 #30611cars addedneutralGT3 now permits current FP spec line cars to compete while maintaining their full FP rule set.
T4 Wrong Part Number on 320i Spec Line #30645wordingneutralT4 BMW 320i 14-15 part number corrected from 20121.140 to E10-20-031-01-22.
T4 Civic Type R Brake Rotors #29817weightslowerT3 Honda Civic Type-R 2020+ allows brake rotor 45251-TGH-A01 with 25 lb penalty.
GT3 Mazda MZR 2.0L Engine #30455inductionfasterGT3 Mazda MZR 2.0L fuel induction restrictor increases from 31 to 32 mm.
GT3 Disfranchised GT3 Mazda, correct choke size #30570inductionslowerGT3 Mazda Renesis and 13B Bridgeport choke reduced from 44mm to 42mm.
T4 Mini Cooper Spec Line Anomalies #30478suspension & brakesunclearT4 Mini Cooper S (02-04, 05-06) suspension/wheel rules simplified; (07-13) gear ratios changed to 3.31, 2.13, 1.48, 1.14, 0.95, 0.82, final drive to 3.65, brakes to 280 mm.
T4 Request CAI Mustang in T4 #30562inductionfasterT4 Ford Mustang V6 05-10 now allows cold air intake.
T4 Request consistency review in GCR #30263wordingslowerT2-T4 clutch disc and pressure plate must be at least 95% of factory OEM weight.
T4 E & O T4 Mustang Wheels #30245tyres & wheelsfasterT4 Ford Mustang V6 05-10 wheels increase from 17 to 18 inches.
T4 2021 Toyota Supra #29567cars addedneutralToyota Supra 2020- newly classified in T2 at 3450 lbs minimum weight with 295 tire and 19-inch wheels.
T4 06-15 MX-5 Durability #29781wordingneutralT4 Mazda MX-5 durability rule now applies to T2-T4 instead of T2-T3 only.
T4 Request for Update to T4 Spec Line for Chevrolet Sonic (2011-) #29838wordingneutralT4 Chevrolet Sonic (2011-) spec clarified: 28mm TIR restrictor placement, PCV plug requirement, and allowed suspension parts listed.
T4 NC MX-5 06-15 Part Number updates for 2021 #29921wordingneutralT4 Mazda MX-5 06-15 removes front and rear end links from suspension package spec.
T4 BMW Z4 2.5L (03-05) Spec Line #30037weight -50 lbsfasterT4 BMW Z4 2.5L (03-05) minimum weight reduced from 3100 to 3050 lbs.
T4 Sway Bars for T4 2016+ MX5 Mazda #30063suspension & brakesneutralT4 2016+ Mazda MX-5 Miata gains allowance for 29mm front and 16mm rear sway bars.
T4 Change part numbers on BRZ, FRS lines in T4 #30104wordingneutralT4 Scion FR-S, Subaru BRZ, and Toyota 86 replace Eibach part 4.10582.880 with 82105.320, 4.10582 and SPC 67660.
T4 T4 Mustang Axle Ratio and Wheels #30149weightslowerT4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.45 or 3.55 ratio at +25 lb penalty.
T4 Request to Classify BMW M2 CS #29523cars addedneutralBMW M2 CS Cup 2020+ classified in T2 at 3625 lbs with 2979cc engine, 10.5x18 wheels, 295 tires.
T4 Allow the SpecMX-5 Update Kit Into Touring 4 for the MX-5 #29681wordingunclearT3 and T4 Mazda MX-5 06-15 now allow Mazda Transmission kit part # 0000-02-5700.
T4 Request Mustang 8.8†rear axle replacement #29860weightslowerT4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.55 final drive, adds 25 lb penalty.
T4 Cap year range on all 86s #29908wordingneutralT3 and T4 FR-S, 86, and BRZ year ranges capped: T3 at 2021, T4 at 2017-2021.
GT3 Mazda MZR SIR Sizing #29555inductionfasterGT3 Mazda MZR and MZR/L5-VE fuel induction sizing changes from 31 to 32.
GT3 Request to Classify 1992-1997 Honda Prelude #29687cars addedneutralGT3 Honda Prelude 1992-1997 classified, 2dr FWD, 104 inch wheelbase.
T4 Alfa Romeo 4C Launch Edition #29531wordingneutralT3 Alfa Romeo 4C Launch Edition now allowed in Spec Lines.
T4 Post Runoffs Feedback for T4 #29752tyres & wheels -50 lbs
GT3 GT Category Wording #29193wordingunclearGT1, GT2, GT3, GTL, GTX now permit turbocharging/supercharging if listed on spec line.
T4 Scion FRS Solo Spec Coupe Gear Ratio #29021otherfasterT4 Scion FRS and Subaru BRZ Solo Spec Coupe final drive ratio changed from 4.30 to 4.10.
GT3 Request to add Mazda 12A Peripheral Port to GT3 rule set #28842cars addedneutralGT3 Mazda 12A Peripheral Port added to rule set, 2300 cc, 2292 lbs.
GT3 TA2 Gurney flap wicker clarification #28874wordingneutralTA2 Gurney flap wording clarified: terminology standardized to 'Gurney flap', height limits and thickness specifications remain 0.50 inch / 0.625 inch or 0.375 inch / 0.0625 inch depending on configuration.
GT3 STO Gurney flap wicker clarification #28883wordingneutralSTO rear wing wording clarified: 'wicker' changed to 'Gurney flap' in maximum chord and mounting height rules.
GT3 GT3 4v SIR size increase. #28931inductionfasterGT3 4v SIR 4-cylinder engines across multiple brands increase fuel induction from 31 to 32.
GT3 Request for Addition to GT3 Approved Turbo List #27576wordingneutralGT3 and STU add Borg-Warner EFR6258 to approved turbocharger list.
T4 T4 RX8 bodywork clarification #28941aeroneutralT4 Mazda RX-8 04-12 now allows OE rear spoiler #F151-V4-920F and OE front air dam #F151-V4-900f-BB.
T4 2006-2015 MX-5 Clarification #28942otherfasterT4 2006-2015 Mazda MX-5 Club Model now allows non-stock wheels; transmission, differential, LSD remain stock.
T4 Request to Add a Vehicle to the Roster (contd.) #27698cars addedunclearCannot read: letter references external document #27663 not provided.
GT3 Request Nissan KA24E specifications #28808inductionslowerGT3 Nissan KA24E loses permission to use 32mm chokes at 2280 lbs for 2011-2012 only.
T4 Request to Classify 2004 Mercedes Benz 320 CLK #27663cars addedneutral2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine and Eibach PN# 2563.140 springs allowed.
T4 Request to change allowed header part # for T4 06-15 Miata #28223wordingneutralT4 06-15 Mazda MX-5 now allows header part numbers 0000-06-5407 or 0000-06-5407-NC.
T4 Z3M Roadster Weight #28437weightfasterT3 BMW Z3 M & Coupe 1998-1999 weight reduced from 3350 to 3150 lbs.
GT3 Error Regarding Mazda Engine Listing #28119induction +245 lbsslowerGT3 Mazda MZR L5-VE gets 31mm SIR restrictor, weight up from 1950 to 2195 lbs, direct injection banned.
T4 Request for 12-13 and 14-15 Honda Civic Springs #27848wordingneutralT4 Honda Civic Si 12-13 and 14-15 now allow H&R and HPD springs up to 700 pounds with 47mm restrictor.
T4 Request to Clarify T4 05-10 Mustang Spring Allowance #27899suspension & brakesneutralT4 Ford Mustang V6 05-10 springs now permitted max 500 lbs front and 400 lbs rear.
GT3 Windshield Clips #27323wordingneutralGT1, GT2, GT3, GTL, GTX may omit windshield clips if factory glass is bonded per original specifications.
T4 Request to Allow Brake Upgrade on T4 Mustang #27329otherneutralT4 Ford Mustang V6 05-10 allowed aluminum driveshaft, any LSD, and Ford brake kit M-2300-D.
T4 Please Switch the Solstice GXP as Specified in T2, to T3 #27413cars added -50 lbsfasterPontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18 x 9.5 inches, Sky weight drops to 3200 lbs.
T4 Request to Classify all Mazda RX8 Models in T3/T4 #27606cars addedneutralMazda 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 & brakesfasterT4 Mazda3 14-18 gains permitted modifications: springs to 800/1000 lbs, 15 lb wheels, cold air intake, camber plates, 25mm rear bar, mirrors, CorkSport arms, header, specific calipers and rotor.
T4 Request to allow aftermarket OEM coolant expansion tank #27763wordingneutralT4 allows aftermarket OEM coolant expansion tanks with no other functional purpose.
T4 Request to allow aftermarket OEM power steering reservoir #27764wordingneutralT4 Mazda MX-5 Club Model 06-15 now allows aftermarket power steering reservoir.
T4 Request for Factory Installed Wings on Subaru BRZ #27831wordingneutralT4 Subaru BRZ and Scion FR-S allowed factory installed wings.
T4 Request for Replacement Clutches #27892wordingneutralT4 now permitted to use any OEM diameter clutch disc and pressure plate, previously T2-T3 only.
T4 Request to Classify Chevy Sonic 1.4 In T4 #27906cars addedneutralChevrolet Sonic 2011+ added to T4 at 2800 lbs with 1364 cc engine and 225 max tire size.
GT3 Request Factory Five Daytona coupe classification #26308cars addedneutralFactory Five Type 65 Coupe R with Ford 302/351 or 5.0/5.2L NA added to GTX-MISC at 2600 lbs.
GT3 Request restrictor size change request #26958inductionslowerGT3 Mazda 13B Bridgeport restrictor reduced from 44mm to 42mm.
GT3 Request to Classify Alfa Romeo 4C #27322cars addedneutralGT3 Alfa Romeo 4C classified with 1742cc engine, 33mm TIR restrictor, 2325 lbs minimum weight.
GT3 Request for Mazda 2.5l MZR/L5-VE #27570induction -245 lbsfasterGT3 Mazda MZR/L5-VE gets unrestricted induction, drops 245 lbs to 1950, limited to GT2 prep.
GT3 GT3 turbo engines add Honda #28033cars addedneutralGT3 Honda K20C1 turbocharged engine added with 33 mm TIR restrictor, 2350 lbs minimum weight.
GT3 GT3 wing end plate #28035aerounclearGT3 wing end plates change from 11.00 by 4.00 inches rectangle to maximum 64 square inches.
T4 Clarification of On-Board Fire System for T2 #27183wordingneutralT2 requires onboard fire system; T3 and T4 may have one per GCR 9.3.
T4 Mustang Ecoboost and GT Transmission #27439otherunclearT3 Ford Mustang EcoBoost 2015- gains three transmission gear ratio options.
T4 BRZ/FRS/86 Tire Size in T4 #27660tyres & wheelsslowerT4 BRZ, FR-S, and 86 maximum tire size reduced from 245 to 225.
T4 NC MX5 2006-2015 Spec Adjustment Request #27739weight -75 lbsfasterT4 Mazda MX-5 Club Model 06-15 minimum weight cut from 2625 to 2550 lbs.
T4 T4 RX8 Classification Error #27902wordingneutralMazda RX-8 Base/R3 (04-12) reclassified in T3 and T4 to include Sport and GT variants.
T4 Request to add Toyota 86 GT to Spec Line #27910cars addedneutralToyota 86 GT (2017-) added to T3 and T4 Spec Line.
GT3 Request to Add SR16VE to GT-3 Spec Lines #27357cars addedneutralGT3 Nissan adds SR16VE engine, 1596cc, 1690 lbs, unrestricted induction.
GT3 Requesting Increase in Choke Diameter for Mazda 12A Bridgeport #27043inductionfasterGT3 Mazda 12A Bridgeport gains optional 42mm choke at 2010 lbs minimum weight.
T4 Request spare tire/wheel clarification #27012wordingneutralT2-T4 spare tire/wheel rules clarified: removable covers can be removed with hardware and bracketry.
T4 Research E&O Mazda MX5 #27112suspension & brakesslowerT4 Mazda MX-5 Club (06-15) gains suspension package with 100 lbs weight increase, allows RX8 hubs and SM5 suspension, permits non-OEM LSD with 50 lbs penalty.
T4 MR2 Spyder Year Correction #26936wordingneutralT4 Toyota MR-2 Spyder 16V DOHC years corrected from 01-05 to 00-07.
T4 Request to allow piggy back ECU on 2000 Mazda Protégé #26085enginefasterT4 Mazda Protégé ES 2000 now allows piggyback ECU tuning device; OBD2 requirement waived.
T4 Request helper spring as optional #26678suspension & brakesslowerT4 Mazda MX5 Club Model 06-15 allows suspension package with 100 lbs weight increase including helper springs.
GT3 Request GTX Fuel injection for previous GT-1 tube frame cars #26141inductionfasterGTX tube frame cars gain fuel injection with 90mm maximum throttle body size.
GT3 Request to Classify Ligier JS2 R #26535cars addedneutralLigier JS2 R classified in GTX, no performance parameters specified in filing.
GT3 26076 revised Spec line chart #26528engineunclearGT3 Mazda 13B and Renesis engines reclassified with new weight specs ranging 2080–2350 lbs.
GT3 Request Ride Height Clarification #26600wordingneutralGT1 and GT2/GT3/LITE ride height requirements removed from GCR sections 9.1.2.D.5.a.1 and 9.1.2.F.7.b.
T4 Request to classify 2000 - 2001 BMW 323 #25096cars addedneutralT4 BMW 323 (98-00) newly classified at 3450 lbs with 50mm flat plate restrictor and M52TUB25 engine required.
GT3 Request clarification on bridge porting for rotary #26076weightslowerGT3 13B and Renesis rotaries gain 200 lbs minimum weight; 13B Peripheral Port to 2400, Bridge Port to 2400, Renesis Peripheral Port to 2450, Bridge Port to 2450.
T4 Correct Mazda MX-5 Hard Top Notes #26137wordingneutralT4 Mazda MX-5 Club (06-15) and (2016-), T3 MX-5 Cup and Miata (2016-) hardtop rules clarified; wording changes to permitted parts and specifications.
T4 Consider opening class rules to allow any thermostat #26187wordingneutralT2, T3, T4 now allow any thermostat serving only OE intent, previously restricted.
T4 Cap 2016 Mazda Miata year at 2018 #26388wordingneutralT3 and T4 Mazda MX-5 Miata eligibility capped at 2018 model year, effective 2019-03-01.
T4 2012-2015 Honda Civic Si Performance Request #26129suspension & brakesfasterT4 Honda Civic Si 2012-2015 permitted sway bars increased to 32mm front and rear.
GT3 GTX Homologation table update #26034cars addedneutralGTX FIA GT3: Audi R8 40mm restrictor 2900 lbs, BMW Z4 70mm 2800 lbs, Ferrari 488 35mm restrictor 3025 lbs classified.
T4 Errors, Omissions, and Updates (Various) #22414wordingneutralT4 Ford Fiesta ST years corrected to 14-; T4 Fiat 124/Abarth Edition years added 16-18; battery rule clarified.
T4 Request for Adjustments to fiat 124 specline #25371inductionfasterT4 Fiat 124 Abarth Edition restrictor changes from 29mm flat plate to 30mm TIR.
T4 Add Clarification to Spec Car Classifications Vehicle Spec #25774wordingneutralT1-T3 spec cars receive clarifications on permitted modifications, documentation requirements, and rule conformance; no performance changes.
T4 Clarify Subframe Bushings Permitted for T2-T4 #25800wordingneutralT2-T4 subframe bushings may now be replaced with non-spherical bushings of any material.
T4 Consider Solo SSC cross over classification into T4 #25802cars addedneutralScion FR-S and Subaru BRZ 13-16 Solo Spec Coupes added to T4, both 1998cc, 2570 lbs, 225/45/17 tires.
Best is the class's fastest lap in that event's qualifying or race sessions, with the driver who set it, how many cars set a time that session and how close the top five were; a best from fewer than three cars is greyed. With two or more classes, "vs" is the gap of each class's best to the first class's at the same event. Newest event first. The coloured figure under each value is the change from the previous event that has one (green is quicker, red slower). Whole laps only, so events with different sector layouts still compare. Weather and track condition are not accounted for.