T1 vs T3 vs GT3U pace at Buttonwillow Raceway Park
Quickest here:T1 1:46.465 Ian Barberi, Cal Club 2025 qualifying · T3 1:55.675 Scotty B White, Cal Club 2026 race · GT3U 1:55.650 Michael Lewis, Cal Club 2025 race
T1T3GT3Usolid race · dashed qualifying · slower is lower
T1T3GT3Usolid race · dashed qualifying · each class's best lap as a share of T1's at the same event (the reference class, changeable above); 100% is level, higher is quicker
Event
T1
T3
GT3U
Qual best
Race best
Trap
Qual best
Race best
Trap
vs T1
% of T1
Qual best
Race best
Trap
vs T1
% of T1
Cal Club 2026 CALCL262026-02-21
1:59.760Ed Gless · only car+13.295s (+12.49%)
1:59.123Ed Gless · only car+11.689s (+10.88%)
120.7Ed Gless-18.6 mph (-13.3%)
1:55.970Scotty B White · fastest of 4 · top 4 within 10.5s+0.005s (+0.00%)
1:55.675Scotty B White · fastest of 5 · top 5 within 12.1s-0.522s (-0.45%)
137.2Scotty B White+25.7 mph (+23.1%)
-3.448squal -3.790s
97.1%qual 96.8%
34 rule changes (T1: 13, T3: 18, GT3U: 3)11 weight · 4 tyres & wheels · 3 cars added · 2 induction · 2 suspension & brakes · 1 removed · 11 wording · T1 Corvette C6 LS1/LS6 Spec Line reinstated: 3200 lbs minimum weight, 70mm restrictor required. · T3 Ford Mustang V6 Spec Line expands to include 2005-2010 chassis and body with 2011-2014 engine. · T3 Nissan 350Z DE Motor loses 25 lbs to 3100, HR Motor loses 25 lbs to 3250. · T2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously prohibited except in specified examples. · T1 Spec Line restrictor changes from 70mm flat plate to unspecified new specification. · T3 Ford Spec Mustang restrictor opens to 45mm, weight drops to 3400 lbs. · T3 BMW Spec E9X tire width increases to 255 from 225; spec E9X tire or any DOT permitted. · T3 SpecE46 permitted tire width increases from 225 to 245. · 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. · Unable to summarize: letter states intent but provides no actual rule changes to S2000 specification. · T1 non-GT4 cars: multiple restrictors enlarged (70mm to 73mm, 75mm to 78mm, 55mm to 60mm, 61mm to 70mm); one weight increased to 3600. · T1 BMW M3 E92 (08-13) Spec Line 1090 removed entirely. · T3 Ford Mustang EcoBoost loses optional 2-piece 355mm Brembo rotor brake kit option with 50 lb penalty. · T3 Honda S2000 wheels grow to 17x9.0 front and 17x10 rear; tyres widen to 255 front and 275 rear. · T3 and T4 Mazda MX-5 Miata models add approved gear kit PT#-0000-02-6100 to notes. · 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. · T2, T3, T4 Spec Lines table header changed from T2 to ET. · BMW Spec E46 in T3 updates to SpecE46 rules Version 3.0. · STU Spec Line GT3U minimum weight reduced from plus 250 to plus 225 pounds; wheel and tire options clarified with weight adjustments. · Porsche 981 GT4 Clubsport added to T1 as spec line 4085, minimum weight 3100 lbs with driver. · T1 Honda S2000 minimum weight reduced from 2950 lbs to 2900 lbs. · T1 BMW E46 M3 permits BMW #GS7D36SG aftermarket sequential transmission in SL# 1060 and 1070. · T1 BMW M3 E92 minimum weight reduced to 3300 lbs. · T1 Mustang Darkhorse R gets 315 front and rear tyres, loses 500 lbs minimum weight to 3600. · T3 Ford Mustang V6 15-17 weight drops 50 lbs to 3350, brake options clarified with M2300V now 50 lb penalty or Brembo alternative. · T3 BMW Spec E46 rules updated to Version 3.0 from Version 1.1. · STU-GT3U non-TCR cars may reduce weight by 4% after all other modifiers. · Cadillac CT4-V Blackwing added to T1 Spec Line 1115, 3564cc, 3750 lbs minimum weight. · T3 BMW Spec E46 updates to SpecE46 rules Version 1.1 dated Jan. 6, 2025. · T3 Ford Mustang V6 11-14 minimum weight drops 25 lbs to 3325. · STU GT3U minimum weight increases 150 to 250 pounds. · T1 Mustang Spec 1430 restrictor opens 60mm to 65mm; Spec 1460 weight rises to 3500 lbs, restrictor 70mm; Corvette 1190 restrictor opens 67mm to 70mm; BMW 1090 restrictor narrows 40mm to 35mm; BMW 1100 weight rises to 3350 lbs.showhide
T1 LS1 into Corvette C6 Spec Line Request #39716cars addedneutralT1 Corvette C6 LS1/LS6 Spec Line reinstated: 3200 lbs minimum weight, 70mm restrictor required.
T3 Please change 2011-2014 Mustang V6 Spec Line to 2005-2014 #39558wordingneutralT3 Ford Mustang V6 Spec Line expands to include 2005-2010 chassis and body with 2011-2014 engine.
T3 Nissan 350Z Weight Request #39598weight -25 lbsfasterT3 Nissan 350Z DE Motor loses 25 lbs to 3100, HR Motor loses 25 lbs to 3250.
T3 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.
T1 additional T1 adjustment #39520inductionunclearT1 Spec Line restrictor changes from 70mm flat plate to unspecified new specification.
T3 Request to Allow Spec Mustang to Touring 3 in Appendix M Trim #39196weight -50 lbsfasterT3 Ford Spec Mustang restrictor opens to 45mm, weight drops to 3400 lbs.
T3 Tire Help for Spec E9X in T3 #39222tyres & wheelsfasterT3 BMW Spec E9X tire width increases to 255 from 225; spec E9X tire or any DOT permitted.
T3 SpecE46 Tire Sizing #39292tyres & wheelsfasterT3 SpecE46 permitted tire width increases from 225 to 245.
T3 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.
T3 Clarify T4 Brake Rotor Allowance #39503suspension & brakesneutralT4 Performance now permits 1-piece alternative rotors matching spec line sizes; alternate brake kits allowed same.
T1 Keep S2000 Classification #39344wordingunclearUnable to summarize: letter states intent but provides no actual rule changes to S2000 specification.
T1 Correcting and updating T1 GT4 spec lines #39394weight
T1 BOP adjustments to non GT4 T1 cars #39406induction +100 lbsfasterT1 non-GT4 cars: multiple restrictors enlarged (70mm to 73mm, 75mm to 78mm, 55mm to 60mm, 61mm to 70mm); one weight increased to 3600.
T1 Remove T1 Spec Line #39407removedneutralT1 BMW M3 E92 (08-13) Spec Line 1090 removed entirely.
T3 T3 Ecoboost Mustang clarification #39236wordingunclearT3 Ford Mustang EcoBoost loses optional 2-piece 355mm Brembo rotor brake kit option with 50 lb penalty.
T3 Make the S2000 Competitive Again #38470tyres & wheelsfasterT3 Honda S2000 wheels grow to 17x9.0 front and 17x10 rear; tyres widen to 255 front and 275 rear.
T3 ND Gearset Request for T4 #39166wordingneutralT3 and T4 Mazda MX-5 Miata models add approved gear kit PT#-0000-02-6100 to notes.
T3 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.
T3 Incorrect Touring Heading #38451wordingneutralT2, T3, T4 Spec Lines table header changed from T2 to ET.
T3 correct letter 37421 #38204wordingunclearBMW Spec E46 in T3 updates to SpecE46 rules Version 3.0.
GT3U Table C: STU-GT3U Clarification #38268weightfasterSTU Spec Line GT3U minimum weight reduced from plus 250 to plus 225 pounds; wheel and tire options clarified with weight adjustments.
T1 Acceptance of Porsche 981 GT4 Clubsport into T1 #36664cars addedneutralPorsche 981 GT4 Clubsport added to T1 as spec line 4085, minimum weight 3100 lbs with driver.
T1 Request to Restore T1 Honda S2000 to Proper Weights #37644weight -50 lbsfasterT1 Honda S2000 minimum weight reduced from 2950 lbs to 2900 lbs.
T1 DCT Transmission in E46 #37964wordingneutralT1 BMW E46 M3 permits BMW #GS7D36SG aftermarket sequential transmission in SL# 1060 and 1070.
T1 Reduce E92 M3 Minimum Weight to 3050 #38092weightfasterT1 BMW M3 E92 minimum weight reduced to 3300 lbs.
T1 Finalize Spec Line for T1 Darkhorse #38106tyres & wheelsfasterT1 Mustang Darkhorse R gets 315 front and rear tyres, loses 500 lbs minimum weight to 3600.
T3 S550 Mustang #38061weight -50 lbsfasterT3 Ford Mustang V6 15-17 weight drops 50 lbs to 3350, brake options clarified with M2300V now 50 lb penalty or Brembo alternative.
T3 correct letter 37421 #38204wordingunclearT3 BMW Spec E46 rules updated to Version 3.0 from Version 1.1.
GT3U TCR Rulesets #37981weightfasterSTU-GT3U non-TCR cars may reduce weight by 4% after all other modifiers.
T1 Cadillac CT4-V Blackwing #38003cars addedneutralCadillac CT4-V Blackwing added to T1 Spec Line 1115, 3564cc, 3750 lbs minimum weight.
T3 SpecE46 Tire Change #37421wordingunclearT3 BMW Spec E46 updates to SpecE46 rules Version 1.1 dated Jan. 6, 2025.
T3 S197 Mustang V6 in T3 #37594weight -25 lbsfasterT3 Ford Mustang V6 11-14 minimum weight drops 25 lbs to 3325.
T1 Correct and make new T1 BOP adjustments. #37737weight +75 lbsunclearT1 Mustang Spec 1430 restrictor opens 60mm to 65mm; Spec 1460 weight rises to 3500 lbs, restrictor 70mm; Corvette 1190 restrictor opens 67mm to 70mm; BMW 1090 restrictor narrows 40mm to 35mm; BMW 1100 weight rises to 3350 lbs.
Cal Club 2025 CALCL252025-02-22
1:46.465Ian Barberi · fastest of 2
1:47.434Ian Barberi · fastest of 3 · top 3 within 11.8s
139.3Drew Delmonico
1:55.965Roger Eagleton · fastest of 6 · top 5 within 5.4s
1:56.197Scotty B White · fastest of 6 · top 5 within 3.8s
111.5J. David Orem
+8.763squal +9.500s
108.2%qual 108.9%
2:00.536Michael Lewis · fastest of 2
1:55.650Michael Lewis · fastest of 2
108.8Michael Lewis
+8.216squal +14.071s
107.6%qual 113.2%
297 earlier rule changes on record, in force before Cal Club 2025 (from 2019)69 cars added · 48 weight · 21 induction · 21 tyres & wheels · 18 suspension & brakes · 9 aero · 7 engine · 3 removed · 97 wording · 4 other · T1 Mustang gains 125 lbs to 3600, restrictor shrinks 65mm to 60mm. Corvette gains 50 lbs to 3500, restrictor shrinks 70mm to 67mm. BMW deleted. · T1 E46 M3 Spec Line 1050 allows VAC Motorsports throttle body VAC-TB-S54 on 3.250L engine instead of Dinan. · T1 Chevrolet Corvette C8 (2023-23) minimum weight reduced from 3600 lbs to 3500 lbs. · T1 Chevrolet Camaro Gen 5 restrictor increases from 75mm to 80mm flat plate. · T1 Audi R8 GT4 Spec Line #4020 maximum tyre size changes to 315 DOT, 305/645, or 30/65-18 (f), 33/68-18 (r) Non-DOT. · T3 Nissan 350Z HR Engine FPR restrictor increases from 47mm to 49mm. · 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. · T2, T3, T4 remove nine, nine, and thirty-six expired spec lines respectively, effective 2025-01-01. · Ford Spec Mustang moves to T3 with 44mm bore restrictor, 275 max tire, 3450 lbs minimum weight. · T3 Ford Mustang V6 (11-14) and (15-17) now permit cold air intake. · T1 GT4 tire sizes adjusted across ten cars: most non-DOT rear to 305/660, Audi and McLaren 305/645, Camaro and Mustang 305/680. · BMW M4 GT4 (G82) added to T1 GT4 at 3525 lbs minimum weight with Red power stick control. · T1 Spec Lines now permits 5.5 inch clutch in Engine Notes. · T1 GT4 Spec Line 4020 restrictor opens from 44mm to 45mm, minimum weight drops to 3400 lbs. · Mustang Darkhorse R added to T1 homologated cars at 3,250 lbs minimum with 305/315 tires, ineligible for Runoffs until 3 Super Tour events. · T1 Corvette may roll or flatten wheel opening lips for tire clearance; plastic fenders may remove lips if edge thickness matches basic material. · T1 E46 M3 S54 can now use Dinan Throttle Body #D760-3400 on 3.250L engine. · T3 VW Golf R (12-13 and 15-18) 36mm TIR placement now allows OEM turbo inlet, removing 60mm distance limit from impeller. · T2 and T3 Mustang spec lines remove redundant driveshaft alternate/aluminum allowance wording. · T2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors. · 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. · T4 BMW 320i 14-15 Spec Line expires 12/31/24 removed; Turner Motorsports intercooler #024703TMS02 allowed. · Cadillac CTS 02-07 3.6L classified in T3. · T3 BMW 328i/330i (06-12) model name updated; BMW 320i (14-15) newly classified at 3050 lbs. · T3 Subaru WRX STI max model year extended to 21, max tire size increased to 275. · T3 Honda HPD Civic Si FE1 newly classified with 1498cc engine, 18x8 wheels, 245 tires, 2950 lbs minimum weight. · T3 Subaru WRX STI 03-07 drops 100 lbs to 3200; Legacy GT/Spec B 05-09 drops 150 lbs to 3200. · T3 Honda Civic Si (2017-2021) restrictor removed, weight to 2950 lbs, Runoffs eligibility requires 3 Super Tour events. · T3 Subaru STI (15-20) and WRX STI (03-07) permitted to use OEM spec block #IAG-ENG-S550 and head studs. · Audi TT Coupe 08-14 classified in T3 with 36mm TIR restrictor, 1984cc, 3200 lbs minimum weight. · T3 Mazda MX5 Miata/Club/RF (19-24) newly classified at 2550 lbs, 17x8.5 wheels, 245 tyres, 280 mm brakes. · Ford Mustang GT 5.0L and V6 now permit Track/Performance Package parts in T2 and T3. · T2-T4 Ford Mustangs: remove 25 lbs penalty for non-OEM driveshaft, clarify alternate driveshaft allowances. · T3 Nissan 350Z DE engine now permits cold air intake. · Audi S4 (2000-2002) moves to T3 with 3400 lbs minimum weight, 38mm turbo inlet restrictor required. · T3 BMW Z4 3.0si expands to include 3.0i Roadster and Coupe (07-08); hardtop permitted with positive fasteners. · T3 Mazda MX-5 Global Cup Miata ND1/ND2 tire size changes to 225 DOT specification. · Mercedes AMG-C63 S (2023) classified in T1 with 4000 lbs minimum weight and 3700 restrictor. · T3 and T4 Mazda RX-8 may remove or disable factory oil injection system. · T2, T3, T4 driveshafts may use alternative materials or one-piece units; non-OEM adds 25 lbs. · Audi S4 00-02 in T3 must compete in 3 Super Tour events before Runoffs eligibility. · T1 Honda S2000 classified with 2400 lb minimum weight, 2950 cc displacement, 4.75" supercharger pulley. · Pontiac GTO 2006-2009 LS1 added to T1 as Spec Line 1590, 5700 cc, 3400 lbs minimum. · T3 Spec Z 350Z rear wheel width increases to 10 inches; HR Engine restrictors change from 42mm to 44mm. · Audi S4 2000-2002 classified in T3 at 3400 lbs with 38mm turbo inlet restrictor required. · T2-T4 Spec Lines remove wheelbase requirement, replace with Required Restrictor specification. · T2 and T3 Nissan 370Z brake rotors enlarged: front 320x28 to 355x32mm, rear 320x16 to 350x20mm vented. · T3 Ford Mustang V6 (11-14) restrictor requirement removed; (15-17) brake penalty reduced to +50 lbs from +100 lbs. · T3 Nissan 350Z and 370Z now allow brake booster vacuum regulator, must not be in-car adjustable. · T3 Ford Mustang 4.6L restrictor holes increased from 40 mm to 45 mm. · T3 Mazda RX-8 Spec Line retention appeal directed to letter #35584 for ruling. · Mazda RX-8 04-12 expiration date removed; no longer expires 12/31/24. · T3 Subaru WRX (02-05) spec line expiration deadline removed; class now permanent. · C8 Corvette T1 restrictor plate increases from 70mm to 72mm flat plate. · T1 NEW class removes 23 spec lines including Acura NSX, Ferrari, Porsche 996, Nissan Z cars, and others; Porsche 997 spec line 1680 expiration removed. · T3 Golf R 15-18 max wheel width increases to 9 inches, max tire size to 255. · T2, T3, T4 battery replacement wording simplified; OEM weight tolerance requirement removed. · T3 Ford Mustang V6 (11-14) gains approved strut tower brace and sway bar kit options. · T3 Ford Mustang EcoBoost 2015- intake restrictor increases from 35mm to 36mm TIR. · 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. · T1-GT4 batch adjustments: five cars lighter, two heavier, restrictors and ECU maps changed, five models now eligible for Runoffs. · T1 spec lines 1000, 1010, 1020, 1040, 1360, 1400–1410, 1520–1680, 1700–1720 deleted entirely. · T3 Pontiac Solstice GXP front brake rotor increases from 296 to 355 mm vented. · T3 Nissan 350Z DE motor loses 75 lbs to 3125; HR motor gains 47mm restrictors, up from 44mm. · T3 Nissan 370Z model years expanded to include NISMO Edition through 2022. · T3 2010 Mustang GT 4.6 now allows 2013-14 GT style front/rear fascia, hood, and associated assemblies. · T3 BMW SpecE46 minimum weight drops 50 lbs to 2850. · T3 Subaru STI (15-20) minimum weight increases 100 lbs to 3450; all three STI variants get larger turbo inlet restrictors. · T1 Chevrolet Corvette C5 LS2 added with 6000cc displacement, 3300 lbs minimum weight, 72mm flat plate restrictor. · T1 Chevrolet Corvette C7 (14-19) including Z51, Grandsport newly classified as homologated car. · T1 Gen 5 Camaro minimum weight drops 75 lbs to 3475; restrictor increases 70mm to 75mm. · T1 Aston Martin Vantage permitted to use OEM Sportshift II transmission. · Pontiac GTO 2006-2009 re-integrated into T1 with LS2 at 3400 lbs, 72mm restrictor, and LS3 at 3500 lbs, 61mm restrictor. · T1 Porsche 997-1 GT3 Cup added at spec line 4210, minimum weight 3050 lbs. · T3 Porsche Cayman (09-12) and (13-16) gear and final drive ratios adjusted; 09-12 6-SPD final drive 3.88 to 3.875, PDK 3.909 to 3.250; 13-16 6-SPD final drive 3.89 unchanged, PDK 3.91 to 3.250. · T3 Volkswagen GTI 06-10 turbo inlet restrictor increases from 36mm to 37mm. · T3 Volkswagen Golf R permitted model years extended from 15-16 to 15-18. · T3 Volkswagen Golf R 15-16 now permits Verkline WAS-048 camber arms. · BMW Spec E9X classified in T3 at 2975 lbs, must conform to SpecE9X rules Version 2.10, tire max 225. · T3 VW Golf GTI and Golf R TIR location clarified to maximum 60mm from impeller. · Chevrolet Camaro GT4-R classified in T1 GT4 Spec Line 4035, minimum weight 3375 lbs, 315 max tire, 63mm restrictor, ineligible for Runoffs. · T1 Dodge Viper ACR / SRT RT-10 and ACR/ACR-X spec lines 1350 and 1370 remove 12/23 expiration. · T1 GT4 McLaren 570S, Mercedes AMG GT4, and Porsche 718 Cayman GT4 CS MR now eligible for Runoffs competition. · T1 GT4 BMW M4 Spec Line Number changed from 4050 to 4030. · T1 Corvette C5 gains approved aero parts: carbon rear spoiler, vented front splitter, side skirts, with 50 lb weight reduction allowed. · 2012-2013 Volkswagen Golf R added to T3 as new entry with 1984cc engine, 3080 lbs DSG/3050 STD, 36mm turbo inlet restrictor. · 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 Nissan 350Z and 370Z maximum tire width increases from 245 to 255. · T3 Pontiac Solstice GXP minimum ride height set to 3 inches. · T1 Dodge Viper ACR/ACR-X restrictor increases from 50mm to 60mm flat plate. · T1 Dodge Viper ACR/ACR-X: Spec Line 1370 restrictor increases to 55mm, Line 1390 decreases to 55mm. · T1 Ford Mustang S197 05-14 now requires OEM 8.8 differential housing. · T1 Chevrolet Camaro Gen 5 LS7 gets two spec lines: 1131 with 70mm restrictor, 1136 with 53mm restrictor, both 3450 lbs minimum. · T1 Chevrolet Camaro Gen 5, Corvette C5 and C6: engine resleeve restricted to stock parameters only, no longer LS3 bore/stroke. · T3 Camaro V6 1LE and LT-I4 Turbo 1LE max wheel diameter increases from 18 to 20 inches. · T3 removes Toyota 2022-up GR Cup and 2022-up GR86 Cup entirely from Spec Lines. · T1 Ford Mustang S197 (05-14) reinstated with 3550 lbs minimum weight, 75mm restrictor, Voodoo engine permitted. · T3 Ford Mustang V6 (15-17) weight drops to 3400 lbs, brake penalties reduced to +100 lbs and +50 lbs. · BMW SpecE46 in T3 loses 50 lbs, to 2900. · T3 adds 2022 Toyota GR Cup and GR86 Cup, both 2387cc, 2700 lbs, 245/620R18 slicks, 332x32F/280x32R brakes. · T1 GT4 weights clarified for nine cars, ranging from 3200 lbs Porsche 718 Cayman to 3575 lbs Aston Martin. · T1-GT4 McLaren 570S and Mercedes AMG GT4 front tires widen to 315 mm. · T3 BMW Spec E46 weight reduced 25 lbs, to 2925. · T3 BMW 323Ci/Is weight reduces to 2750 lbs from 3000 lbs. · T3 BMW SpecE46 must conform to SpecE46 rules Version 2.10, updated from 2.7. · T1 Chevrolet Camaro Gen5 LS3-6160 adds 70mm flat plate restrictor, weight 3550 lbs. · T3 06-10 VW GTI, Jetta GLI allowed to use ECS Tuning performance alternative intercooler. · T1 cars with aftermarket sequential transmissions get 10-inch max bellhousing; non-sequential cars gain 100 lbs weight break. · T1 GT4 all nine cars lose 125 lbs minimum weight with driver, from 3200–3575 to 3075–3450. · T1 removes GCR Section 9.1.9.1.A. and T1 Spec Lines entirely, sunsetting pre-2023 Touring 1 rules. · T3 Porsche Spec Boxster tire rule updates to current SPB rules or any 245 DOT tire. · T3 06-10 VW GTI and Jetta permitted to use OEM VW knuckles 3C0407253F and 3C0407254F. · T3 BMW 320I now permitted to use aftermarket intercooler. · GT4 McLaren 570S maximum tire size changes to 285 front, 315 rear. · Porsche Cayman (13-16) classified in T3 at 3225 lbs with 2700cc engine, 18x9 wheels, 245 tires. · T2/T3 Mustang GT 5.0L and V6 (11-14) may remove upper grille fog lights, replace with mesh or screen. · Hyundai Veloster Turbo 2018-2021 classified in T3 at 3050 lbs with 1584cc engine, 245 max tire size, specific suspension and brake modifications allowed. · T3 Volkswagen GTI and Jetta GLI now permit Verkline WAS-048 adjustable rear camber arms. · Eight GT4 models added to T1 with weights from 3200 to 3575 lbs and restricted power per SRO 2022 rules. · T3 Nissan 350Z and 370Z remove SPC Control Arms 72130, 72125, 72123; permit performance alternative front upper control arms. · T3 Nissan 350Z loses up to 75 lbs and gets 44mm restrictors; 370Z loses 100 lbs. Wheels widened front and rear. · T3 Ford Mustang EcoBoost 2015- turbo inlet restrictor increases from 34mm to 35mm TIR. · 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. · T3 Solstice GXP intercooler options expanded: Hahn HIC-1150 or Dejon FIC-SSA replaced with Performance alternative. · T3 Subaru BRZ 2022- minimum weight up to 2975 lbs; spring rate to 1000 F/R, brake parts allowed without penalty. · T3 Honda S2000 hardtop clarified: OEM, Mugen P/N 0000-04-2312, or aftermarket permitted if OEM roof silhouette retained. · T3 Pontiac Solstice GXP Coupe/Convertible 07-09 tire runout increases from 35mm to 36mm TIR. · T1 Cadillac CTS/CTS-V, Chevrolet Camaro, Pontiac Firebird, Pontiac GTO 6162 OEM minimum weight reduced to 3475 lbs. · BMW 320i (14-15) classified in T3 at 3050 lbs with 18-inch wheels, 255/275 tires, 3.08 final drive. · T3 Subaru BRZ (2022-) and Toyota GR86 (2022-) permit 25mm front and 22mm rear sway bars, OEM trunk spoiler. · T1-LP Ford Mustang FP350S restrictor increases from 70mm to 75mm. · Mercedes Benz AMG GT4 2017-2021 classified T1 Maximum at 3400 lbs minimum weight with HP-controlled SRO Power Level 2 engine. · T3 Honda Civic Si (2017-) spec clarified: wheels to 10" wide allowed with 50 lb. penalty, 1-piece rotor required. · Porsche Boxster Base 2005-2008 newly classified in T3 at 3000 lbs minimum weight. · T2-T4 Touring cars with alternative springs may use performance top hats with spherical bearings on shocks and struts. · T3 Subaru BRZ and Toyota 86 (2022-) wheel size corrected to 18 x 8 in., gear ratios and final drive specified. · T1 Dodge Viper ACR displacement rises to 8400 OEM, minimum weight drops to 3550 lbs. · T1 Limited T1 wording changed to clarify all T1 cars permitted specifications. · T1 Mazda RX-7 classified: 2700 lbs minimum weight, 44mm restrictor, 13B Rotary with single Garrett Turbo #3076. · T2-T4 cars model year 2018+ may use non-OEM ECU with 75 lb weight penalty via spec line adjustment. · T3 Ford Mustang V6 (11-14) minimum weight reduced to 3350 lbs. · T3 Subaru STI 15-20 now allows SPC lower control arm 67660. · T1 Cadillac CTS/CTS-V, Chevrolet Camaro, Pontiac Firebird, Pontiac GTO LS3 minimum weight reduced to 3475 lbs. · T1 Camaro maximum displacement 7011 loses 50 lbs, to 3500. · T1 removes 33mm brake rotor thickness limit; rotors now unrestricted on thickness. · T3 BMW 330i/Ci 01-06 loses 60 lbs to 3125 and runs 245 tyres instead of 275. · T3 Nissan 370Z 09-16 and 370Z NISMO 09-13 weight increased to 3375 lbs. · T3 FWD models standardized to 36mm turbo inlet restrictor; Focus ST brakes enlarged, final drive changed to 4.06 (1-4) 2.95 (5-6); GTI 14.5-17 gear ratios revised DSG/STD. · 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. · T3 VW GTI/Jetta GLI allows any 4-piston brake kit instead of StopTech only, max 355mm x 32mm. · T3 Scion FR-S/Toyota 86 GT and Subaru BRZ lose 75 lbs, to 2675 lbs minimum weight. · 2022+ Subaru BRZ and Toyota 86 newly classified in T3 at 2750 lbs with 245 max tires. · T2-T4 clarified: grill opening area may increase max 16 sq in for radiator cooling only, retaining factory mesh shape. · T3 BMW 335i eligible model years narrowed from 08-13 to 07-10. · T3 BMW 135i model years restricted from 08-13 to 08-10. · T2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted. · T3 Nissan Z 350Z and 370Z suspension control arm options expanded from 'and' to 'or' for SPC parts. · T2, T3, T4 clarify that spec lines listing permitted or allowed parts are alternatives to category rules, not replacements. · T1 Mazda MX-5 Miata MazdaSpeed minimum weight rises to 2550 lbs, restrictor increases to 42mm. · T1 Chevrolet Corvette Cadillac XLR classified for model years through 2019. · T3 BMW Z4 M Coupe model years corrected from 2007 to 06-08. · T3 Subaru STI 15-20 weight increases 150 lbs, to 3350. · T4 Volkswagen Passat, Jetta 1.8T adds 2014 model year to eligible years. · T3 BMW 323Ci/Is 98-00 minimum weight reduced from 3100 to 3000 lbs. · Subaru STI (15-20) newly classified in T3 at 3200 lbs minimum weight with 37mm turbo inlet restrictor required. · T1 BMW E46/E36/Z3 minimum weight increases to 2700 lbs, 3.4L engine car to 2750 lbs. · T1 Dodge Viper SRT-10 restrictor increases from 45mm to 57mm. · T1 Chevrolet Corvette Cadillac XLR LS6 engine now permits Casting #799 heads with no other head modifications. · T3 Porsche Spec Boxster minimum weight reduced from 2600 to 2550 lbs. · T3 Porsche Cayman 06-08 wheel size changes from 18x8 to 18x9 inches. · T3 Mazda MX-5 Global Cup Miata ND2 with sequential gearbox allowed +100 lbs weight adder. · T1 Ford Mustang Shelby/GT350/GT500 5.0L Coyote restrictor opens from 65mm to 70mm flat plate. · T1 Dodge Viper SRT-10 restrictor increases from 45mm to 57mm. · T1-LP Chevrolet Corvette C7 restrictor increases from 70 to 73 mm. · T1-LP Corvette Z06 06-13 now allows aluminum chassis replacement with equivalent OE steel chassis. · T3 Honda Civic Type-R 2020+ allows brake rotor 45251-TGH-A01 with 25 lb penalty. · T1 Chevrolet Camaro with 6162 displacement minimum weight reduced to 3500 lbs. · T1-LP Chevrolet Corvettes C5 Z06, C6 Grand Sport, and Z06 dry sump kit notes clarified to remove contradictions. · T3 Porsche Boxster/Boxster S (00-04) now permits any OEM or aftermarket hardtop retaining OEM roof silhouette. · T3 Mazdaspeed3 07-09 and 10-13 now allow CorkSport Gen-6-999-10 or Autotech 10-127-100K fuel pumps. · T2-T4 clutch disc and pressure plate must be at least 95% of factory OEM weight. · Porsche Cayman 06-08 classified in T3 with 2687cc engine, 3050 lbs minimum weight, 18-inch wheels, 245 tires. · T1 LP removes 50 lbs weight allowance for stock headers, adds aero device allowance up to 100 lbs, permits headers. · T3 Ford Mustang EcoBoost gets 35mm TIR; Nissan 350Z DE Motor down 25 lbs to 3250; Mustang V6 down 50 lbs to 3475, restrictor tightened 55mm to 58mm. · T1 Ford Mustang Challenge 3-valve maximum displacement changes to 4600/5000. · T1 BMW E46 now allows carbon or fiberglass OEM-style dashboards with 25 pound penalty. · T1 Ford Mustang/Thunderbird limited to Shelby/Shelby GT350/GT500 models through 2018. · Dodge Viper ACR classified in T1 with 8400cc displacement, 3600 lbs minimum weight, 55mm restrictor. · BMW M2CS Club Sport classified in T1-LP Spec Lines effective 2021-02-01. · Porsche 997.1 GT3 Cup (2006-2011) classified in T1 at 3600cc, 3150 lbs minimum weight. · Toyota Supra 2020- newly classified in T2 at 3450 lbs minimum weight with 295 tire and 19-inch wheels. · T3 Chevrolet Camaro LT-I4 Turbo 1LE reclassified to 2016- model year, max tire size 275, TIR required 35mm. · T2 Ford Mustang GT 5.0L (15-17) gear ratios corrected to 3.66, 2.43, 1.69, 1.32, 1.00, 0.65 or 4.17, 2.34, 1.52, 1.14, 0.87, 0.69. · T3 Spec Boxster tire size increased from 225 to 245 DOT, permitting wider tires. · T1 Chevrolet Corvette Z06 years extended from 06-12 to 06-13. · 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. · T2 and T3 Nissan 350Z and 370Z permit 44011-RC350 rear caliper kit and SZ350 rotors. · 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. · T1 Corvette C8 Z51 gets wider wheels and tyres, weight drops 100 lbs to 3550. · T3 Alfa Romeo 4C Launch Edition now allowed in Spec Lines. · Honda Civic Type R (2017-) classified in T3 at 3350 lbs with 1996cc engine, 245 max tire, 20-inch max wheel. · T1 rear wing Gurney flap wording clarified: Gurney flap in chord length and mounting height rules. · T3 Honda Accord (2009) V6 manual classified: 3471cc, 3450 lbs, 245 max tire, 19-inch wheels. · T3 Mazda MX-5 Global Cup Miata ND2 2016-2019 must meet all ND2 Global Cup rules without appendix reference. · T3 VW GTI FSI gains turbo inlet restrictor allowance to 60mm, R32 brakes, Stoptech 4-piston kit, and Neuspeed intake options. · Cannot read: letter references external document #27663 not provided. · T1 and T2 Corvettes may convert leaf spring suspension to coilover with 800 lb max spring rate allowed. · 2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine and Eibach PN# 2563.140 springs allowed. · T3 Nissan 350Z Spec 2 DE Engine loses 57mm flat plate restrictor requirement. · T1 Porsche 996 GT3 Cup eligible model years changed from 2002-2005 to 1998-2004. · T1 Corvette and Cadillac XLR permitted to install SCRSPLR-001 rear spoiler with OE bodywork. · T1 Gen 5 Camaro allowed 366mm OEM rear rotor and caliper without weight penalty. · T3 Ford Mustang EcoBoost and V6 sway bars allowed up to 35mm front, 25mm rear. · T3 BMW Z3 M & Coupe 1998-1999 weight reduced from 3350 to 3150 lbs. · T1 Porsche 996 Spec Lines now allows 996 Cup Replica Rear deck lid. · T1 Acura NSX Turbo World Challenge and Audi TTRS GTS 2011 now require DOT tires per GCR section 9.3. · T1 BMW E46 wagon with S54 engine allowed; displacement corrected from 3200 to 3250cc. · T3 05-10 V8 Mustang allowed parts clarified: strut tower brace, radiator, springs to 500 lbs/in front and 300 lbs/in rear, sway bars, damper kit. · T3 Ford Mustang Coupe GT & Shelby GT 4.6L 05-10 adds permitted final drive ratios: 3.31, 3.55 or 3.73. · T1 adds Subaru WRX/WRX STI 2005-2020 at 3000 lbs minimum weight with 46 mm restrictor. · T1 Ford Mustang GT (15-17) and GT5.0L (2018-) weight raised to 3500 lbs; Brembo BBK 380mm now at no penalty; restrictors removed from notes. · T1 Ford Mustang/Thunderbird 5000 Coyote OEM reclassified to include 2015–2017 and 2018+ model years with 65mm restrictor for 18+. · T1 BMW M3 E92 carbon dash allowed with 25 lb penalty. · T1 Corvette C5 Z06, C6 coupe, C6 Grand Sport, and Z06 may convert leaf springs to conventional coilover suspension. · BMW 330i 2006-2012 added to T3 with 2996cc engine, 3200 lbs minimum weight. · 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. · T3 adds 2017 Ford Fiesta ST, 1596cc, 2600 lbs minimum weight, 245 max tire, 17x9 wheels. · 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. · T3 Nissan 350Z and 370Z HR engines: restrictor plate enlarged from 37mm to 42mm, weight increased 50-100 lbs. · T3 Mazda MX-5 Global Cup Miata (2016-) tires now 215/610 R17 BF Goodrich G-Force Slick or wet; removes touring tire requirement. · T3 05-10 Mustang GT 4.6L suspension upgrades allowed: tower braces, radiator, 500/300 lbs/in springs, sway bars, dampers, control arms, shocks, driveshaft. · T3 BMW SpecE46 updates to SpecE46 rules Version 2.6 to 2.7, tire width to 225 maximum. · T3 Subaru WRX 02-05 minimum weight drops 100 lbs to 3250. · 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. · T3 Scion FR-S/Toyota 86 and Subaru BRZ year range extended from 13-17 to 13-20. · T3 Mazda NC MX-5 gains two alternate six-speed and one five-speed transmission gear ratio option. · T1-LP Chevrolet Camaro 1LE 2016- weight drops to 3500 lbs, restrictor increases to 70mm flat plate. · T2-T4 spare tire/wheel rules clarified: removable covers can be removed with hardware and bracketry. · Ford Mustang Challenge returns to T1 as E&O, 4600 cc, 3300 lbs minimum, no restrictor. · T1 Chevrolet Corvette Cadillac XLR year range corrected from 04-09. · T3 Mk7 GTI gains R32 brake package, 4-piston Stoptech kit to 355mm, and ECS street shield allowance. · T1 Camaro, CTS, Firebird, GTO restrictor increases from 67mm to 70mm flat plate. · T3 BMW E36 M3 96-00 allows alternate sway bars, 35mm front and 27mm rear. · T2-T4 clarifies DOT tire requirements; must have minimum U speed rating and be DOT certified; touring spec line supersedes other rules. · 09-12 Porsche Cayman newly classified in T3 at 3150 lbs with 2900cc engine. · Ford Mustang EcoBoost 3.5L classified in T1 at 3300 lbs minimum weight with 31mm restrictor. · T1 Corvette C5 body allowed C7 carbon aero parts, plus 50 lbs. · T1 Audi TTRS must conform to July 24th, 2015 revision 7 GTS rules instead of December 14th, 2011 revision 3. · T1 minimum ride height established at 3.5 inches, measured at rocker panel without driver. · T1 Porsche 928 S4/GTS-R minimum weight reduced to 3200 lbs, throttle restrictor removed. · T3 Chevrolet Camaro LT-I4 Turbo 1LE (2019-) classified with 1998 cc engine, 3450 lbs minimum weight, 245 max tire size. · T3 Honda Civic Si 2017- minimum weight reduced 100 lbs, to 2900. · Honda Civic Si 2017+ with alternate cage classified in T3 at 3075 lbs minimum weight. · T3 classifies 2014-2017 Volkswagen GTI with 35 mm turbo inlet restrictor, 3080 lbs DSG, 3050 lbs standard. · Porsche 928 S4/928 GTS-R newly classified in T1 at 3500 lbs minimum with 60mm flat plate restrictor. · BMW E36 M3 (96-00) BMWCCA I Sport newly classified in T3 at 3100 lbs minimum weight. · T1-LP Ford Mustang GT 5.0L 2018+ classified at 3400 lbs with 65mm flat plate restrictor. · T1-LP Ford Mustang GT 5.0L 2018+ classified at 3400 lbs with 65mm flat plate restrictor. · T3 Subaru WRX (2015-) classified at 3275 lbs with 35mm turbo inlet restrictor required. · 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. · T3 Mazda MX-5 NC 06-15 wheel width increases from 17x7 to 17x8. · T3 Mazda MX-5 NC 06-15 now allows any aftermarket header. · T3 Saturn Sky intercooler tolerance increases from 32mm to 35mm TIR; new calipers and springs permitted. · T2, T3, T4 now allow any thermostat serving only OE intent, previously restricted. · T3 Subaru Legacy GT/Spec B 05-09 newly classified with 2457cc, 18×9 wheels, 245 tires, 3300 lbs. · T3 and T4 Mazda MX-5 Miata eligibility capped at 2018 model year, effective 2019-03-01. · T3 Mazda Mazdaspeed3 07-09 front brake disc increases to 320mm vented, rear to 300mm solid. · T1-LP Mustang GT350(R) spec line replaced with 2015+ model parameters including 5163cc engine, 3650 lbs curb weight, 315 tire size. · Ford Mustang FP350S (2018) classified in T1-LP at 3600 lbs with 18×11 wheels and 315 tires. · T1 suspension rules clarified: spherical bearings and bushings now explicitly permitted, alternate control arms allowed. · T1 Porsche 996 drops 200 lbs to 3000; 996 GT3 Cup drops 150 lbs to 3000; 997 drops 50 lbs to 3100. · Porsche 997 T1 Maximum now allows OEM PDK transmission alongside existing drivetrain options. · T1 Acura NSX Turbo World Challenge weight to 3100 lbs, restrictor to 44mm. · T1-T3 spec cars receive clarifications on permitted modifications, documentation requirements, and rule conformance; no performance changes. · T4 Ford Fiesta ST years corrected to 14-; T4 Fiat 124/Abarth Edition years added 16-18; battery rule clarified. · T3 BMW SpecE46 rules reference updated from Appendix N to Version 2.6 Effective Jan 1, 2019. · T3 Nissan 350Z Track/Touring/Standard/Nismo 03-08 permitted to use Nissan brake kit part number 41000-BRKIT. · 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. · T3 field loses 50 lbs across 27 cars including Acura TL, BMW 335i, Camaro, Mustang, Miata, RX-8, 370Z, WRX. · T3 Ford Mustang EcoBoost gains Ford Motorsports or Brembo brake kit options, +100 lb. · T3 FR-S/86 and BRZ: wheels to 17x9, tires to 255, weight to 2750 lbs. · T3 BMW SpecE46 now permits any DOT tire up to 225 width as alternate to spec tire.showhide
T1 T1 Parity Compared to GT4 #37170weight +125 lbsslowerT1 Mustang gains 125 lbs to 3600, restrictor shrinks 65mm to 60mm. Corvette gains 50 lbs to 3500, restrictor shrinks 70mm to 67mm. BMW deleted.
T1 Clarification of Request Approval #37273 #37399engineunclearT1 E46 M3 Spec Line 1050 allows VAC Motorsports throttle body VAC-TB-S54 on 3.250L engine instead of Dinan.
T1 C8 Corvette Facts #37400weight -100 lbsfasterT1 Chevrolet Corvette C8 (2023-23) minimum weight reduced from 3600 lbs to 3500 lbs.
T1 Camaro Gen 5 Competitive Disadvantage #37440inductionfasterT1 Chevrolet Camaro Gen 5 restrictor increases from 75mm to 80mm flat plate.
T1 Tire Changes in the Rules for GT4 #37497tyres & wheelsunclearT1 Audi R8 GT4 Spec Line #4020 maximum tyre size changes to 315 DOT, 305/645, or 30/65-18 (f), 33/68-18 (r) Non-DOT.
T3 350z BOP #37427inductionfasterT3 Nissan 350Z HR Engine FPR restrictor increases from 47mm to 49mm.
T3 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.
T3 Remove spec lines that have expired #37269removedneutralT2, T3, T4 remove nine, nine, and thirty-six expired spec lines respectively, effective 2025-01-01.
T3 Request to Move Spec Mustang to Touring 3 (from T2) #37080cars addedneutralFord Spec Mustang moves to T3 with 44mm bore restrictor, 275 max tire, 3450 lbs minimum weight.
T3 3.7 Mustangs BoP #37186inductionfasterT3 Ford Mustang V6 (11-14) and (15-17) now permit cold air intake.
T1 Changes to T1 Tires for GT4 and Other Cars #35383tyres & wheelsunclearT1 GT4 tire sizes adjusted across ten cars: most non-DOT rear to 305/660, Audi and McLaren 305/645, Camaro and Mustang 305/680.
T1 G82 M4 GT4 inclusion in T1 #35864cars addedneutralBMW M4 GT4 (G82) added to T1 GT4 at 3525 lbs minimum weight with Red power stick control.
T1 Alt. Clutch Allowance #36606wordingneutralT1 Spec Lines now permits 5.5 inch clutch in Engine Notes.
T1 BOP Changes Need Updates #36667weight -150 lbsfasterT1 GT4 Spec Line 4020 restrictor opens from 44mm to 45mm, minimum weight drops to 3400 lbs.
T1 Request Ford Performance Darkhorse R in T1 #37136cars addedneutralMustang Darkhorse R added to T1 homologated cars at 3,250 lbs minimum with 305/315 tires, ineligible for Runoffs until 3 Super Tour events.
T1 Car Mods for T1 Corvette under line item 1150 #37173wordingneutralT1 Corvette may roll or flatten wheel opening lips for tire clearance; plastic fenders may remove lips if edge thickness matches basic material.
T1 Increased Bore Throttle Bodies for E46 M3 S54 Engine #37273enginefasterT1 E46 M3 S54 can now use Dinan Throttle Body #D760-3400 on 3.250L engine.
T3 Amend TIR Placement on VW #36175wordingneutralT3 VW Golf R (12-13 and 15-18) 36mm TIR placement now allows OEM turbo inlet, removing 60mm distance limit from impeller.
T3 Redundant Verbiage Regarding Mustang Spec Lines for Driveshaft #36484wordingneutralT2 and T3 Mustang spec lines remove redundant driveshaft alternate/aluminum allowance wording.
T3 Fuel Emissions Components #37076wordingneutralT2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors.
T3 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.
T3 Evaporative emissions systems #37130wordingneutralT2, T3, T4 fuel cell cars may remove charcoal canisters, emissions valves, and sensors.
T3 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.
T3 Move Spec Boxster to T4 #37158cars addedneutralPorsche Spec Boxster moves to T4, minimum weight 2750 lbs, requires 3 Super Tour events before Runoffs eligibility.
T3 BMW 320i Spec Line #37204wordingneutralT4 BMW 320i 14-15 Spec Line expires 12/31/24 removed; Turner Motorsports intercooler #024703TMS02 allowed.
T3 Classification for a 2005 Cadillac CTS 3.6 liter 6 speed manual #37224cars addedneutralCadillac CTS 02-07 3.6L classified in T3.
T3 Request to Classify BMWs #37226cars addedneutralT3 BMW 328i/330i (06-12) model name updated; BMW 320i (14-15) newly classified at 3050 lbs.
T3 Make adjustments to the 2015 STI Spec line #37246tyres & wheelsfasterT3 Subaru WRX STI max model year extended to 21, max tire size increased to 275.
T3 class a civic #37294cars addedneutralT3 Honda HPD Civic Si FE1 newly classified with 1498cc engine, 18x8 wheels, 245 tires, 2950 lbs minimum weight.
T3 Older STI in T3 #37300weight -100 lbsfasterT3 Subaru WRX STI 03-07 drops 100 lbs to 3200; Legacy GT/Spec B 05-09 drops 150 lbs to 3200.
T3 Honda Civic Si (2017+) #36249inductionfasterT3 Honda Civic Si (2017-2021) restrictor removed, weight to 2950 lbs, Runoffs eligibility requires 3 Super Tour events.
T3 Subaru Reliability Help #36284wordingneutralT3 Subaru STI (15-20) and WRX STI (03-07) permitted to use OEM spec block #IAG-ENG-S550 and head studs.
T3 spec line for 36073 #36338cars addedneutralAudi TT Coupe 08-14 classified in T3 with 36mm TIR restrictor, 1984cc, 3200 lbs minimum weight.
T3 36131 #36339cars addedneutralT3 Mazda MX5 Miata/Club/RF (19-24) newly classified at 2550 lbs, 17x8.5 wheels, 245 tyres, 280 mm brakes.
T3 Mustang T2/T3 #35877wordingunclearFord Mustang GT 5.0L and V6 now permit Track/Performance Package parts in T2 and T3.
T3 T2-T4 Driveshaft Mistake...? #36050weightfasterT2-T4 Ford Mustangs: remove 25 lbs penalty for non-OEM driveshaft, clarify alternate driveshaft allowances.
T3 E&O: #35174 (Derek Chan) 350Z Parity Request #36116inductionfasterT3 Nissan 350Z DE engine now permits cold air intake.
T3 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.
T3 Z4 Roadster Eligibility #36196cars addedneutralT3 BMW Z4 3.0si expands to include 3.0i Roadster and Coupe (07-08); hardtop permitted with positive fasteners.
T3 Global MX5 Tre change #36046tyres & wheelsunclearT3 Mazda MX-5 Global Cup Miata ND1/ND2 tire size changes to 225 DOT specification.
T1 Please Expedite classing the C63 Mercedes #35987cars addedneutralMercedes AMG-C63 S (2023) classified in T1 with 4000 lbs minimum weight and 3700 restrictor.
T3 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.
T3 Driveshafts #35916weightslowerT2, T3, T4 driveshafts may use alternative materials or one-piece units; non-OEM adds 25 lbs.
T3 Audi S4 HST requirement #35918wordingneutralAudi S4 00-02 in T3 must compete in 3 Super Tour events before Runoffs eligibility.
T1 Honda S2000 #35582cars addedneutralT1 Honda S2000 classified with 2400 lb minimum weight, 2950 cc displacement, 4.75" supercharger pulley.
T1 9.1.9.1 T1 new category item/ line 26 rule to expire Jan 1 2023 #35411cars addedneutralPontiac GTO 2006-2009 LS1 added to T1 as Spec Line 1590, 5700 cc, 3400 lbs minimum.
T3 Spec Z Interchange in T3 #34416tyres & wheelsfasterT3 Spec Z 350Z rear wheel width increases to 10 inches; HR Engine restrictors change from 42mm to 44mm.
T3 please classify 2000-2002 Audi s4 #35306cars addedneutralAudi S4 2000-2002 classified in T3 at 3400 lbs with 38mm turbo inlet restrictor required.
T3 Reorganize Spec Lines #35375wordingunclearT2-T4 Spec Lines remove wheelbase requirement, replace with Required Restrictor specification.
T3 370Z Brake Rotor Size Correction #35487suspension & brakesneutralT2 and T3 Nissan 370Z brake rotors enlarged: front 320x28 to 355x32mm, rear 320x16 to 350x20mm vented.
T3 T3 V6 Mustang help #35526enginefasterT3 Ford Mustang V6 (11-14) restrictor requirement removed; (15-17) brake penalty reduced to +50 lbs from +100 lbs.
T3 Nissan 370Z - Brake System Allowance - Brake Booster #35556suspension & brakesneutralT3 Nissan 350Z and 370Z now allow brake booster vacuum regulator, must not be in-car adjustable.
T3 Mustang Help #35559inductionfasterT3 Ford Mustang 4.6L restrictor holes increased from 40 mm to 45 mm.
T3 Appeal for Retention of T3 Mazda RX-8 Spec Line (Letter #35378) #35577wordingunclearT3 Mazda RX-8 Spec Line retention appeal directed to letter #35584 for ruling.
T3 Request to Keep the Mazda Rx-8 in Touring 3 #35584wordingneutralMazda RX-8 04-12 expiration date removed; no longer expires 12/31/24.
T3 Subaru WRX (02-05) Appeal #35656wordingneutralT3 Subaru WRX (02-05) spec line expiration deadline removed; class now permanent.
T1 C8 Corvette T1 Restrictor Plate Request #35213inductionfasterC8 Corvette T1 restrictor plate increases from 70mm to 72mm flat plate.
T1 The Cars Have Expired #35379removedneutralT1 NEW class removes 23 spec lines including Acura NSX, Ferrari, Porsche 996, Nissan Z cars, and others; Porsche 997 spec line 1680 expiration removed.
T3 15-18 Golf R Alignment with Existing GTI and R Speclines #35235tyres & wheelsfasterT3 Golf R 15-18 max wheel width increases to 9 inches, max tire size to 255.
T3 More Car Lightening Stuff #35319weightfasterT2, T3, T4 battery replacement wording simplified; OEM weight tolerance requirement removed.
T3 Open Strut Tower Brace Options for Ford Mustang V6 (11-14) #35322wordingneutralT3 Ford Mustang V6 (11-14) gains approved strut tower brace and sway bar kit options.
T3 Mustang ecoboost #35351inductionfasterT3 Ford Mustang EcoBoost 2015- intake restrictor increases from 35mm to 36mm TIR.
T3 Inclusion of B-C spec cars in T4 #35374cars addedneutralT4 now permits C-Spec cars to compete alongside B-Spec cars.
T3 T2-T4 Set expiration dates on spec lines #35378wordingneutralT2-T4 spec lines for 46 cars expire 12/31/24; appeal required to continue.
T1 GT4 batch adjustment in T1 #35162other -85 lbsunclearT1-GT4 batch adjustments: five cars lighter, two heavier, restrictors and ECU maps changed, five models now eligible for Runoffs.
T3 T3 Solstice Brakes #35106suspension & brakesslowerT3 Pontiac Solstice GXP front brake rotor increases from 296 to 355 mm vented.
T3 350Z Parity Request #35174weightslowerT3 Nissan 350Z DE motor loses 75 lbs to 3125; HR motor gains 47mm restrictors, up from 44mm.
T3 Requested Update of Model Years of 370Z #35231wordingneutralT3 Nissan 370Z model years expanded to include NISMO Edition through 2022.
T3 Update Request for 2010 Mustang GT 4.6 #35234wordingneutralT3 2010 Mustang GT 4.6 now allows 2013-14 GT style front/rear fascia, hood, and associated assemblies.
T3 SE46 Continued Parity/ Cold Air Intake request #35267weight -50 lbsfasterT3 BMW SpecE46 minimum weight drops 50 lbs to 2850.
T3 Please help the Subaru STIs. #35278weight +100 lbsslowerT3 Subaru STI (15-20) minimum weight increases 100 lbs to 3450; all three STI variants get larger turbo inlet restrictors.
T1 New T1 add spec line for C5 corvette LS2 engines (Copy from C6) #33764cars addedneutralT1 Chevrolet Corvette C5 LS2 added with 6000cc displacement, 3300 lbs minimum weight, 72mm flat plate restrictor.
T1 C7 Corvette Rule Change Request #34897cars addedneutralT1 Chevrolet Corvette C7 (14-19) including Z51, Grandsport newly classified as homologated car.
T1 Camaro Gen 5 Weight Reduction Due to Competitive Disadvantage #35092weight -75 lbsfasterT1 Gen 5 Camaro minimum weight drops 75 lbs to 3475; restrictor increases 70mm to 75mm.
T1 Addendum to Letter #35022: Drivetrain Rule #35105wordingneutralT1 Aston Martin Vantage permitted to use OEM Sportshift II transmission.
T1 2004 - 2006 Pontiac GTO Re-Integration Back Into T1 #34403cars addedneutralPontiac GTO 2006-2009 re-integrated into T1 with LS2 at 3400 lbs, 72mm restrictor, and LS3 at 3500 lbs, 61mm restrictor.
T1 Request to Classify Porsche 997-1 GT3 Cup #34561cars addedneutralT1 Porsche 997-1 GT3 Cup added at spec line 4210, minimum weight 3050 lbs.
T3 Porsche Cayman Transmissions and Ratios #34891wordingfasterT3 Porsche Cayman (09-12) and (13-16) gear and final drive ratios adjusted; 09-12 6-SPD final drive 3.88 to 3.875, PDK 3.909 to 3.250; 13-16 6-SPD final drive 3.89 unchanged, PDK 3.91 to 3.250.
T3 2006-10 Volkswagen GTI - Weight Reduction request and KO4 Turbo #34414inductionfasterT3 Volkswagen GTI 06-10 turbo inlet restrictor increases from 36mm to 37mm.
T3 Adding Model Years to T3 Golf R Spec Line #34612wordingneutralT3 Volkswagen Golf R permitted model years extended from 15-16 to 15-18.
T3 Rear Camber Arms for T3 VW Golf R #34613wordingneutralT3 Volkswagen Golf R 15-16 now permits Verkline WAS-048 camber arms.
T3 Classing Spec E90 Cars in SCCA #34791cars addedneutralBMW Spec E9X classified in T3 at 2975 lbs, must conform to SpecE9X rules Version 2.10, tire max 225.
T3 TIR location requirement in VW Golf Spec lines #35048wordingneutralT3 VW Golf GTI and Golf R TIR location clarified to maximum 60mm from impeller.
T1 Why no Camaro? #34421cars addedneutralChevrolet Camaro GT4-R classified in T1 GT4 Spec Line 4035, minimum weight 3375 lbs, 315 max tire, 63mm restrictor, ineligible for Runoffs.
T1 Request to Remove Expiration from T1 spec lines #1350 & #1370 #34470wordingneutralT1 Dodge Viper ACR / SRT RT-10 and ACR/ACR-X spec lines 1350 and 1370 remove 12/23 expiration.
T1 Remove #34475wordingneutralT1 GT4 McLaren 570S, Mercedes AMG GT4, and Porsche 718 Cayman GT4 CS MR now eligible for Runoffs competition.
T1 Error in T1 GT4 numbering scheme- #34578wordingneutralT1 GT4 BMW M4 Spec Line Number changed from 4050 to 4030.
T1 C5 Approved Aero That Was Mistakenly Deleted #34374aerofasterT1 Corvette C5 gains approved aero parts: carbon rear spoiler, vented front splitter, side skirts, with 50 lb weight reduction allowed.
T3 2012-2013 Golf R - added to T3 #34413cars addedneutral2012-2013 Volkswagen Golf R added to T3 as new entry with 1984cc engine, 3080 lbs DSG/3050 STD, 36mm turbo inlet restrictor.
T3 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.
T3 rule book corrections #34437otherfasterT3 BMW 320i (14-15) gains aftermarket intercooler permission; T4 loses it.
T3 Allowing 255 Tire Width for Nissan 350z #34471tyres & wheelsfasterT3 Nissan 350Z and 370Z maximum tire width increases from 245 to 255.
T3 Ride Height Correction for the T3 Solstice. #34615wordingneutralT3 Pontiac Solstice GXP minimum ride height set to 3 inches.
T1 Viper Cleanup #34107inductionfasterT1 Dodge Viper ACR/ACR-X restrictor increases from 50mm to 60mm flat plate.
T1 Viper 8300 OEM FPR Size #34268inductionunclearT1 Dodge Viper ACR/ACR-X: Spec Line 1370 restrictor increases to 55mm, Line 1390 decreases to 55mm.
T1 Ford Mustang S197 (05-14) Clarification #34450wordingneutralT1 Ford Mustang S197 05-14 now requires OEM 8.8 differential housing.
T1 Gen 5 Camaro Engine #33875cars addedneutralT1 Chevrolet Camaro Gen 5 LS7 gets two spec lines: 1131 with 70mm restrictor, 1136 with 53mm restrictor, both 3450 lbs minimum.
T1 Inquiry to letter #33682 #34071engineslowerT1 Chevrolet Camaro Gen 5, Corvette C5 and C6: engine resleeve restricted to stock parameters only, no longer LS3 bore/stroke.
T3 2016+ Camaro 1LE - Max Wheel Diameter #34003tyres & wheelsfasterT3 Camaro V6 1LE and LT-I4 Turbo 1LE max wheel diameter increases from 18 to 20 inches.
T3 2022 Toyota GR Cup for T3 #34448removedneutralT3 removes Toyota 2022-up GR Cup and 2022-up GR86 Cup entirely from Spec Lines.
T1 Request to reinstate T1 S197 Mustang #34048cars addedneutralT1 Ford Mustang S197 (05-14) reinstated with 3550 lbs minimum weight, 75mm restrictor, Voodoo engine permitted.
T3 S550 Reconcile With S197 #34093weight -75 lbsfasterT3 Ford Mustang V6 (15-17) weight drops to 3400 lbs, brake penalties reduced to +100 lbs and +50 lbs.
T3 SE46 Parity Help #34178weight -50 lbsfasterBMW SpecE46 in T3 loses 50 lbs, to 2900.
T3 2022 Toyota GR Cup for T3 discussion #34234cars addedneutralT3 adds 2022 Toyota GR Cup and GR86 Cup, both 2387cc, 2700 lbs, 245/620R18 slicks, 332x32F/280x32R brakes.
T1 T1 GT4 adjustments #33786wordingneutralT1 GT4 weights clarified for nine cars, ranging from 3200 lbs Porsche 718 Cayman to 3575 lbs Aston Martin.
T1 Touring 1 Tire Sizes #34191tyres & wheelsfasterT1-GT4 McLaren 570S and Mercedes AMG GT4 front tires widen to 315 mm.
T3 Request Spec E46 in T3 Weight Adjustment #33897weight -25 lbsfasterT3 BMW Spec E46 weight reduced 25 lbs, to 2925.
T3 E36 2.5L 323is Weight Reduction #33975weightfasterT3 BMW 323Ci/Is weight reduces to 2750 lbs from 3000 lbs.
T3 Update SpecE46 Spec Line to Current SpecE46 Ruleset #34016wordingunclearT3 BMW SpecE46 must conform to SpecE46 rules Version 2.10, updated from 2.7.
T1 Clarification for Camaro Gen5 2010-2015 #33739inductionslowerT1 Chevrolet Camaro Gen5 LS3-6160 adds 70mm flat plate restrictor, weight 3550 lbs.
T3 Request to all ECS Tuning inner-cooler to 06-10 VW GTI spec #33769wordingneutralT3 06-10 VW GTI, Jetta GLI allowed to use ECS Tuning performance alternative intercooler.
T1 Sequential Gearbox Limitations in T1 #33691wordingneutralT1 cars with aftermarket sequential transmissions get 10-inch max bellhousing; non-sequential cars gain 100 lbs weight break.
T1 T1 GT4 adjustments #33786weightfasterT1 GT4 all nine cars lose 125 lbs minimum weight with driver, from 3200–3575 to 3075–3450.
T1 Sunset of pre 2023 Touring 1 Rules. #33916wordingneutralT1 removes GCR Section 9.1.9.1.A. and T1 Spec Lines entirely, sunsetting pre-2023 Touring 1 rules.
T3 T3 Boxster S GCR request #33687wordingneutralT3 Porsche Spec Boxster tire rule updates to current SPB rules or any 245 DOT tire.
T3 OEM VW Steering Spindle Replacements 06-10 VW GTI and Jetta #33732wordingneutralT3 06-10 VW GTI and Jetta permitted to use OEM VW knuckles 3C0407253F and 3C0407254F.
T3 BMW 320I intercooler #33762otherfasterT3 BMW 320I now permitted to use aftermarket intercooler.
T1 Corrections to T1 Spec Lines #33678tyres & wheelsunclearGT4 McLaren 570S maximum tire size changes to 285 front, 315 rear.
T3 Request to classify 2014 Base Cayman #33159cars addedneutralPorsche Cayman (13-16) classified in T3 at 3225 lbs with 2700cc engine, 18x9 wheels, 245 tires.
T3 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.
T3 Hyundai Classification #33498cars addedneutralHyundai Veloster Turbo 2018-2021 classified in T3 at 3050 lbs with 1584cc engine, 245 max tire size, specific suspension and brake modifications allowed.
T3 Adjustable Rear Camber Arms for VW (All Generations) #33572wordingneutralT3 Volkswagen GTI and Jetta GLI now permit Verkline WAS-048 adjustable rear camber arms.
T1 GT4 section to Current T1 Rules. #33632cars addedneutralEight GT4 models added to T1 with weights from 3200 to 3575 lbs and restricted power per SRO 2022 rules.
T3 350z SPC Upper Control Arm Safety Concerns #33020suspension & brakesneutralT3 Nissan 350Z and 370Z remove SPC Control Arms 72130, 72125, 72123; permit performance alternative front upper control arms.
T3 Request Help for 350z #33379weight -100 lbsfasterT3 Nissan 350Z loses up to 75 lbs and gets 44mm restrictors; 370Z loses 100 lbs. Wheels widened front and rear.
T3 Ecoboost Acknowledgement #33506inductionfasterT3 Ford Mustang EcoBoost 2015- turbo inlet restrictor increases from 34mm to 35mm TIR.
T3 Touring (T2-T5) Category #33617cars addedneutralT5 class added as regional-only; T5 tyres maximum width 225, minimum aspect ratio 45.
T3 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.
T3 Solstice GXP in T3 #33501wordingneutralT3 Solstice GXP intercooler options expanded: Hahn HIC-1150 or Dejon FIC-SSA replaced with Performance alternative.
T3 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.
T3 S2000 Hard Top Clarification #32779wordingneutralT3 Honda S2000 hardtop clarified: OEM, Mugen P/N 0000-04-2312, or aftermarket permitted if OEM roof silhouette retained.
T3 T3 Pontiac Solstice- #33081tyres & wheelsslowerT3 Pontiac Solstice GXP Coupe/Convertible 07-09 tire runout increases from 35mm to 36mm TIR.
T1 Correct Camaro Spec Line From Letter #30791 response to 3475lbs #32824weight -25 lbsfasterT1 Cadillac CTS/CTS-V, Chevrolet Camaro, Pontiac Firebird, Pontiac GTO 6162 OEM minimum weight reduced to 3475 lbs.
T3 Classify Car #32691cars addedneutralBMW 320i (14-15) classified in T3 at 3050 lbs with 18-inch wheels, 255/275 tires, 3.08 final drive.
T3 2022 BRZ Sway bar and lip spoiler. #32703suspension & brakesfasterT3 Subaru BRZ (2022-) and Toyota GR86 (2022-) permit 25mm front and 22mm rear sway bars, OEM trunk spoiler.
T1 Fix FP350S limited prep and Shelby 350 full prep issues #31680inductionfasterT1-LP Ford Mustang FP350S restrictor increases from 70mm to 75mm.
T1 Request to Classify AMG GT4 #32610cars addedneutralMercedes Benz AMG GT4 2017-2021 classified T1 Maximum at 3400 lbs minimum weight with HP-controlled SRO Power Level 2 engine.
T3 correct wording #31750wordingneutralT3 Honda Civic Si (2017-) spec clarified: wheels to 10" wide allowed with 50 lb. penalty, 1-piece rotor required.
T3 2005-2008 Porsche Boxster 2.7 #31999cars addedneutralPorsche Boxster Base 2005-2008 newly classified in T3 at 3000 lbs minimum weight.
T3 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.
T3 2022 Subaru BRZ and Toyota 86 twins #32483wordingneutralT3 Subaru BRZ and Toyota 86 (2022-) wheel size corrected to 18 x 8 in., gear ratios and final drive specified.
T1 Viper/Z06 Parity #31942weight -50 lbsfasterT1 Dodge Viper ACR displacement rises to 8400 OEM, minimum weight drops to 3550 lbs.
T1 Discrepancy in T1 allowances #32293wordingneutralT1 Limited T1 wording changed to clarify all T1 cars permitted specifications.
T3 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.
T3 T3 Mustang V8/V6 #31959weight -50 lbsfasterT3 Ford Mustang V6 (11-14) minimum weight reduced to 3350 lbs.
T3 Subaru STI (15-20) Missing part #32294suspension & brakesneutralT3 Subaru STI 15-20 now allows SPC lower control arm 67660.
T3 Touring 3 BOP adjustments for 2022 #31481weight +75 lbs
T3 BMW 330i Minimum Comp Weight #31606tyres & wheels -60 lbsfasterT3 BMW 330i/Ci 01-06 loses 60 lbs to 3125 and runs 245 tyres instead of 275.
T3 Adjust T3 370Z #31748weight +50 lbsslowerT3 Nissan 370Z 09-16 and 370Z NISMO 09-13 weight increased to 3375 lbs.
T3 TIR changes for FWD T3 models #31825inductionfasterT3 FWD models standardized to 36mm turbo inlet restrictor; Focus ST brakes enlarged, final drive changed to 4.06 (1-4) 2.95 (5-6); GTI 14.5-17 gear ratios revised DSG/STD.
T3 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.
T3 BRZ vs BRZ TS #32022wordingneutralT3 Spec Lines Subaru BRZ TS (13-21) added to class specification wording.
T3 Remove StopTech 4 piston BBK, allow any 4 Piston Kit - VW GTI #33082suspension & brakesneutralT3 VW GTI/Jetta GLI allows any 4-piston brake kit instead of StopTech only, max 355mm x 32mm.
T3 Request FRS/BRZ/86 T3 Weight Reduction #30818weight -75 lbsfasterT3 Scion FR-S/Toyota 86 GT and Subaru BRZ lose 75 lbs, to 2675 lbs minimum weight.
T3 Request to Classify 2022 Toyota 86 / Subaru in T3 & T4 #30931cars addedneutral2022+ Subaru BRZ and Toyota 86 newly classified in T3 at 2750 lbs with 245 max tires.
T3 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.
T3 Please Adjust Years Allowed for BMW 335i to 07-10, not 08-13 #31530wordingneutralT3 BMW 335i eligible model years narrowed from 08-13 to 07-10.
T3 Please Adjust Years Allowed for BMW 135i to 08-10, not 08-13 #31531wordingneutralT3 BMW 135i model years restricted from 08-13 to 08-10.
T3 Request to clarify radiator hoses #31682wordingneutralT2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted.
T3 T3 Nissan Z Suspension Update #31728wordingneutralT3 Nissan Z 350Z and 370Z suspension control arm options expanded from 'and' to 'or' for SPC parts.
T3 Clarify Permitted/Allowed #31743wordingneutralT2, T3, T4 clarify that spec lines listing permitted or allowed parts are alternatives to category rules, not replacements.
T1 Turbo Miata Help #31315weight +200 lbsslowerT1 Mazda MX-5 Miata MazdaSpeed minimum weight rises to 2550 lbs, restrictor increases to 42mm.
T1 Fix the T1 Corvette heading #31528wordingneutralT1 Chevrolet Corvette Cadillac XLR classified for model years through 2019.
T3 Request to correct model years BMW Z4 M Coupe #31371wordingneutralT3 BMW Z4 M Coupe model years corrected from 2007 to 06-08.
T3 Correct letter the 31327 #31563weight +150 lbsslowerT3 Subaru STI 15-20 weight increases 150 lbs, to 3350.
T3 Request to Classify 2014 VW Jetta 1.8t TSI #30436cars addedneutralT4 Volkswagen Passat, Jetta 1.8T adds 2014 model year to eligible years.
T3 Request Weight Reduction 323is #30765weight -100 lbsfasterT3 BMW 323Ci/Is 98-00 minimum weight reduced from 3100 to 3000 lbs.
T3 Class Newer STI in T3 #31327cars addedneutralSubaru STI (15-20) newly classified in T3 at 3200 lbs minimum weight with 37mm turbo inlet restrictor required.
T1 T1 E46 BOP E&O for Letter # 29970 #30934weight +100 lbsslowerT1 BMW E46/E36/Z3 minimum weight increases to 2700 lbs, 3.4L engine car to 2750 lbs.
T1 Request BoP for the Viper in 1 LP #29968inductionfasterT1 Dodge Viper SRT-10 restrictor increases from 45mm to 57mm.
T1 LS6 Alternative Head Question #30074wordingneutralT1 Chevrolet Corvette Cadillac XLR LS6 engine now permits Casting #799 heads with no other head modifications.
T3 Follow-up to letter 29797-Porsche Spec Boxster in T3 Adjustment #30144weight -50 lbsfasterT3 Porsche Spec Boxster minimum weight reduced from 2600 to 2550 lbs.
T3 Wheel Size #30677tyres & wheelsfasterT3 Porsche Cayman 06-08 wheel size changes from 18x8 to 18x9 inches.
T3 Request weight adder to be applied to the Global Cup Miata ND2 #30730weightslowerT3 Mazda MX-5 Global Cup Miata ND2 with sequential gearbox allowed +100 lbs weight adder.
T1 T1-LP - Add Performance Pack, Bullet, Mach 1 to 18+ Mustang #29849inductionfasterT1 Ford Mustang Shelby/GT350/GT500 5.0L Coyote restrictor opens from 65mm to 70mm flat plate.
T1 Request BoP for the Viper in 1 LP #29968inductionfasterT1 Dodge Viper SRT-10 restrictor increases from 45mm to 57mm.
T1 Request to classify C7 and 13Viper in T1 LP #29969inductionfasterT1-LP Chevrolet Corvette C7 restrictor increases from 70 to 73 mm.
T1 Request LP Z06 steel chassis #30589wordingneutralT1-LP Corvette Z06 06-13 now allows aluminum chassis replacement with equivalent OE steel chassis.
T3 Civic Type R Brake Rotors #29817weightslowerT3 Honda Civic Type-R 2020+ allows brake rotor 45251-TGH-A01 with 25 lb penalty.
T1 Request For Reduction in Weight/Penalties for Camaro #30443weightfasterT1 Chevrolet Camaro with 6162 displacement minimum weight reduced to 3500 lbs.
T1 Fix dry sump Contradictions in T1-LP vs T2 #30596wordingneutralT1-LP Chevrolet Corvettes C5 Z06, C6 Grand Sport, and Z06 dry sump kit notes clarified to remove contradictions.
T3 Requesting Variance on Hardtop #30093wordingneutralT3 Porsche Boxster/Boxster S (00-04) now permits any OEM or aftermarket hardtop retaining OEM roof silhouette.
T3 07-09 and 10-13 Mazdaspeed 3 Fuel Pump #30154wordingneutralT3 Mazdaspeed3 07-09 and 10-13 now allow CorkSport Gen-6-999-10 or Autotech 10-127-100K fuel pumps.
T3 Request consistency review in GCR #30263wordingslowerT2-T4 clutch disc and pressure plate must be at least 95% of factory OEM weight.
T3 Request to classify 2006-2008 Cayman #30315cars addedneutralPorsche Cayman 06-08 classified in T3 with 2687cc engine, 3050 lbs minimum weight, 18-inch wheels, 245 tires.
T1 T1 LP Aero adjustments #30196aerounclearT1 LP removes 50 lbs weight allowance for stock headers, adds aero device allowance up to 100 lbs, permits headers.
T3 2020 T3 Suggested Changes #30002wording -50 lbsslowerT3 Ford Mustang EcoBoost gets 35mm TIR; Nissan 350Z DE Motor down 25 lbs to 3250; Mustang V6 down 50 lbs to 3475, restrictor tightened 55mm to 58mm.
T1 Request to Clarify Miller Mustang Classification #28728engineunclearT1 Ford Mustang Challenge 3-valve maximum displacement changes to 4600/5000.
T1 BMW E46 Carbon Dash #29806weightslowerT1 BMW E46 now allows carbon or fiberglass OEM-style dashboards with 25 pound penalty.
T1 Request to Update T1 Mustang Spec Line #30001wordingneutralT1 Ford Mustang/Thunderbird limited to Shelby/Shelby GT350/GT500 models through 2018.
T1 Class BMW M2CS Club Sport #30195cars addedneutralBMW M2CS Club Sport classified in T1-LP Spec Lines effective 2021-02-01.
T1 997.1 GT3 Cup #30229cars addedneutralPorsche 997.1 GT3 Cup (2006-2011) classified in T1 at 3600cc, 3150 lbs minimum weight.
T3 2021 Toyota Supra #29567cars addedneutralToyota Supra 2020- newly classified in T2 at 3450 lbs minimum weight with 295 tire and 19-inch wheels.
T3 Chevrolet Camaro LT-I4 Turbo 1LE (2019-) Model Year to 2016- #30090tyres & wheelsfasterT3 Chevrolet Camaro LT-I4 Turbo 1LE reclassified to 2016- model year, max tire size 275, TIR required 35mm.
T3 Fix T2 Mustang spec line #30106wordingneutralT2 Ford Mustang GT 5.0L (15-17) gear ratios corrected to 3.66, 2.43, 1.69, 1.32, 1.00, 0.65 or 4.17, 2.34, 1.52, 1.14, 0.87, 0.69.
T3 Spec Boxster Tire Size #30159tyres & wheelsfasterT3 Spec Boxster tire size increased from 225 to 245 DOT, permitting wider tires.
T1 Correct T1 Limited Prep Years #29708wordingneutralT1 Chevrolet Corvette Z06 years extended from 06-12 to 06-13.
T3 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.
T3 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.
T3 350Z Rear Caliper Replacement #29710wordingneutralT2 and T3 Nissan 350Z and 370Z permit 44011-RC350 rear caliper kit and SZ350 rotors.
T3 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.
T3 Cap year range on all 86s #29908wordingneutralT3 and T4 FR-S, 86, and BRZ year ranges capped: T3 at 2021, T4 at 2017-2021.
T1 Changes to Corvette C8 #29898tyres & wheels -100 lbsfasterT1 Corvette C8 Z51 gets wider wheels and tyres, weight drops 100 lbs to 3550.
T3 Alfa Romeo 4C Launch Edition #29531wordingneutralT3 Alfa Romeo 4C Launch Edition now allowed in Spec Lines.
T3 Request to Classify Honda Civic Type R in T3 #27840cars addedneutralHonda Civic Type R (2017-) classified in T3 at 3350 lbs with 1996cc engine, 245 max tire, 20-inch max wheel.
T3 Request to classify 2009 Honda Accord v6 manual #28913cars addedneutralT3 Honda Accord (2009) V6 manual classified: 3471cc, 3450 lbs, 245 max tire, 19-inch wheels.
T3 SADEV Sequential Gearbox #28763wordingneutralT3 Mazda MX-5 Global Cup Miata ND2 2016-2019 must meet all ND2 Global Cup rules without appendix reference.
T3 Request for competition adjustment for the MK5 GTI FSI engine #28802suspension & brakesfasterT3 VW GTI FSI gains turbo inlet restrictor allowance to 60mm, R32 brakes, Stoptech 4-piston kit, and Neuspeed intake options.
T3 Request to Add a Vehicle to the Roster (contd.) #27698cars addedunclearCannot read: letter references external document #27663 not provided.
T1 Consider coil spring conversion Corvette in T2 #28824suspension & brakesneutralT1 and T2 Corvettes may convert leaf spring suspension to coilover with 800 lb max spring rate allowed.
T3 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.
T3 Request Nissan 350Z Part Number change #28145enginefasterT3 Nissan 350Z Spec 2 DE Engine loses 57mm flat plate restrictor requirement.
T1 Additional Clarification on 996 Cup in T1 From Letter #28040 #28060wordingneutralT1 Porsche 996 GT3 Cup eligible model years changed from 2002-2005 to 1998-2004.
T1 Request SPEC Corvette Rear Spolier #28182aeroneutralT1 Corvette and Cadillac XLR permitted to install SCRSPLR-001 rear spoiler with OE bodywork.
T1 T1 Rear Brake Rotor Size Exemption for Gen 5 Camaro #28402wordingneutralT1 Gen 5 Camaro allowed 366mm OEM rear rotor and caliper without weight penalty.
T3 2015 + Ford EcoBoost Mustang Sway Bars #28398suspension & brakesneutralT3 Ford Mustang EcoBoost and V6 sway bars allowed up to 35mm front, 25mm rear.
T3 Z3M Roadster Weight #28437weightfasterT3 BMW Z3 M & Coupe 1998-1999 weight reduced from 3350 to 3150 lbs.
T1 Request 996 GT3 Trunk for Wing Allowance. #28153wordingneutralT1 Porsche 996 Spec Lines now allows 996 Cup Replica Rear deck lid.
T1 All Touring, Change DOT Tire Language 9.1.9.1, 9.3.45 #28452wordingneutralT1 Acura NSX Turbo World Challenge and Audi TTRS GTS 2011 now require DOT tires per GCR section 9.3.
T1 Request for E46 wagon with S54 engine in T1 #27427wordingneutralT1 BMW E46 wagon with S54 engine allowed; displacement corrected from 3200 to 3250cc.
T3 Clarify 05-10 V8 Mustang Spring Rates Wording/Adjust Restrictor #28238wordingneutralT3 05-10 V8 Mustang allowed parts clarified: strut tower brace, radiator, springs to 500 lbs/in front and 300 lbs/in rear, sway bars, damper kit.
T3 Correct Touring 3 05-10 Mustang final drive #28288wordingneutralT3 Ford Mustang Coupe GT & Shelby GT 4.6L 05-10 adds permitted final drive ratios: 3.31, 3.55 or 3.73.
T1 Request to include Subaru WRX/STI 02-18 in T1 #24916cars addedneutralT1 adds Subaru WRX/WRX STI 2005-2020 at 3000 lbs minimum weight with 46 mm restrictor.
T1 Request Ford Mustang FP350S T1-LP weight and restrictor change #26662weight +100 lbsslowerT1 Ford Mustang GT (15-17) and GT5.0L (2018-) weight raised to 3500 lbs; Brembo BBK 380mm now at no penalty; restrictors removed from notes.
T1 Request to classify Ford Coyote 3rd Gen OEM #27145cars addedslowerT1 Ford Mustang/Thunderbird 5000 Coyote OEM reclassified to include 2015–2017 and 2018+ model years with 65mm restrictor for 18+.
T1 Request alternate dashboard #27276weightslowerT1 BMW M3 E92 carbon dash allowed with 25 lb penalty.
T1 Request for Allowance of Coil Springs on Limited Prep C6 Corvette #27713suspension & brakesfasterT1 Corvette C5 Z06, C6 coupe, C6 Grand Sport, and Z06 may convert leaf springs to conventional coilover suspension.
T3 2006 BMW E90 330i Sedan Classification #26663cars addedneutralBMW 330i 2006-2012 added to T3 with 2996cc engine, 3200 lbs minimum weight.
T3 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.
T3 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.
T3 Request for 2005 Subaru STI Changes #27658tyres & wheels +50 lbs
T3 Request to Classify 2017 Ford Fiesta ST #27700cars addedneutralT3 adds 2017 Ford Fiesta ST, 1596cc, 2600 lbs minimum weight, 245 max tire, 17x9 wheels.
T3 Clarification of On-Board Fire System for T2 #27183wordingneutralT2 requires onboard fire system; T3 and T4 may have one per GCR 9.3.
T3 Mustang Ecoboost and GT Transmission #27439otherunclearT3 Ford Mustang EcoBoost 2015- gains three transmission gear ratio options.
T3 Nissan 350Z HR Engine Restrictor Plate/Minimum Weight #27442induction +50 lbsslowerT3 Nissan 350Z and 370Z HR engines: restrictor plate enlarged from 37mm to 42mm, weight increased 50-100 lbs.
T3 Request help for the GMX5 #27572tyres & wheelsneutralT3 Mazda MX-5 Global Cup Miata (2016-) tires now 215/610 R17 BF Goodrich G-Force Slick or wet; removes touring tire requirement.
T3 Request for 05-10 Mustang GT Suspension Upgrades #27777suspension & brakesfasterT3 05-10 Mustang GT 4.6L suspension upgrades allowed: tower braces, radiator, 500/300 lbs/in springs, sway bars, dampers, control arms, shocks, driveshaft.
T3 Please Update the BMW SpecE46 Rules #27781wordingneutralT3 BMW SpecE46 updates to SpecE46 rules Version 2.6 to 2.7, tire width to 225 maximum.
T3 Request for 02-03 WRX Spec Line Parts #27864weight -100 lbsfasterT3 Subaru WRX 02-05 minimum weight drops 100 lbs to 3250.
T3 T4 RX8 Classification Error #27902wordingneutralMazda RX-8 Base/R3 (04-12) reclassified in T3 and T4 to include Sport and GT variants.
T3 Request to add Toyota 86 GT to Spec Line #27910cars addedneutralToyota 86 GT (2017-) added to T3 and T4 Spec Line.
T3 Request to add 2018 Subaru BRZ in T3 #27253cars addedneutralT3 Scion FR-S/Toyota 86 and Subaru BRZ year range extended from 13-17 to 13-20.
T3 Request Mazda NC MX-5 alternate transmission gear ratios #27155wordingneutralT3 Mazda NC MX-5 gains two alternate six-speed and one five-speed transmission gear ratio option.
T1 T1 LP 2016 Camaro and Later #27198weight -100 lbsfasterT1-LP Chevrolet Camaro 1LE 2016- weight drops to 3500 lbs, restrictor increases to 70mm flat plate.
T3 Request spare tire/wheel clarification #27012wordingneutralT2-T4 spare tire/wheel rules clarified: removable covers can be removed with hardware and bracketry.
T1 Request to return Ford Mustang Challenge Car to T1 #26751cars addedneutralFord Mustang Challenge returns to T1 as E&O, 4600 cc, 3300 lbs minimum, no restrictor.
T1 Correct years in T1 FP Corvette spec #27023wordingneutralT1 Chevrolet Corvette Cadillac XLR year range corrected from 04-09.
T3 Request guidance for 2014-2017 MK7 Volkswagen GTI #26866wordingneutralT3 Mk7 GTI gains R32 brake package, 4-piston Stoptech kit to 355mm, and ECS street shield allowance.
T1 Request BoP Baten - T1 Camaro - Follow up to Letter # 26145 #26900inductionfasterT1 Camaro, CTS, Firebird, GTO restrictor increases from 67mm to 70mm flat plate.
T3 Request BMW e36 M3 sway bar and links #26885suspension & brakesneutralT3 BMW E36 M3 96-00 allows alternate sway bars, 35mm front and 27mm rear.
T1 Clarify DOT tires touring #26556tyres & wheelsneutralT2-T4 clarifies DOT tire requirements; must have minimum U speed rating and be DOT certified; touring spec line supersedes other rules.
T3 Request to properly class base Porsche Cayman #26276cars addedneutral09-12 Porsche Cayman newly classified in T3 at 3150 lbs with 2900cc engine.
T1 Request to Classify EcoBoost Mustang #25841cars addedneutralFord Mustang EcoBoost 3.5L classified in T1 at 3300 lbs minimum weight with 31mm restrictor.
T1 Request Corvette aerodynamic aids #26265aeroslowerT1 Corvette C5 body allowed C7 carbon aero parts, plus 50 lbs.
T1 Audi TTRS VTS Documentation Revision #26578wordingunclearT1 Audi TTRS must conform to July 24th, 2015 revision 7 GTS rules instead of December 14th, 2011 revision 3.
T1 Request Ride Height Clarification #26599wordingneutralT1 minimum ride height established at 3.5 inches, measured at rocker panel without driver.
T3 Request to classify a 2019 Chevrolet Camaro LT-I4 Turbo 1LE #25731cars addedneutralT3 Chevrolet Camaro LT-I4 Turbo 1LE (2019-) classified with 1998 cc engine, 3450 lbs minimum weight, 245 max tire size.
T3 T3 Civic Si weight change #26294weightfasterT3 Honda Civic Si 2017- minimum weight reduced 100 lbs, to 2900.
T3 Class Civic Si 2017+ w/ alternate cage #26449cars addedneutralHonda Civic Si 2017+ with alternate cage classified in T3 at 3075 lbs minimum weight.
T3 Classify 2014-2017 MK7 Volkswagen GTI for T3 #26695cars addedneutralT3 classifies 2014-2017 Volkswagen GTI with 35 mm turbo inlet restrictor, 3080 lbs DSG, 3050 lbs standard.
T1 Request to classify the Porsche 928GTS/S4 in Touring 1 #26315cars addedneutralPorsche 928 S4/928 GTS-R newly classified in T1 at 3500 lbs minimum with 60mm flat plate restrictor.
T3 Request to allow E36 M3 in T3 prepared to BMWCCA I sport #25195cars addedneutralBMW E36 M3 (96-00) BMWCCA I Sport newly classified in T3 at 3100 lbs minimum weight.
T1 Request Mustang GT Limited Prep 2018 Classification #24431cars addedneutralT1-LP Ford Mustang GT 5.0L 2018+ classified at 3400 lbs with 65mm flat plate restrictor.
T3 Request Mustang GT Limited Prep 2018 Classification #24431cars addedneutralT1-LP Ford Mustang GT 5.0L 2018+ classified at 3400 lbs with 65mm flat plate restrictor.
T3 Classify 2015+ WRX #25832cars addedneutralT3 Subaru WRX (2015-) classified at 3275 lbs with 35mm turbo inlet restrictor required.
T3 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.
T3 Request to allow T3 06-15 Miata 17x8 wheels #26161tyres & wheelsfasterT3 Mazda MX-5 NC 06-15 wheel width increases from 17x7 to 17x8.
T3 Request T3 06-15 Miata header #26162aerofasterT3 Mazda MX-5 NC 06-15 now allows any aftermarket header.
T3 Request Pontiac GXP same allowances to Saturn Sky #26175aerofasterT3 Saturn Sky intercooler tolerance increases from 32mm to 35mm TIR; new calipers and springs permitted.
T3 Consider opening class rules to allow any thermostat #26187wordingneutralT2, T3, T4 now allow any thermostat serving only OE intent, previously restricted.
T3 2005-2009 Legacy GT/Spec B #26384cars addedneutralT3 Subaru Legacy GT/Spec B 05-09 newly classified with 2457cc, 18×9 wheels, 245 tires, 3300 lbs.
T3 Cap 2016 Mazda Miata year at 2018 #26388wordingneutralT3 and T4 Mazda MX-5 Miata eligibility capped at 2018 model year, effective 2019-03-01.
T3 Request correction on brake sizes #26170wordingneutralT3 Mazda Mazdaspeed3 07-09 front brake disc increases to 320mm vented, rear to 300mm solid.
T1 Class 2015+ Mustang GT350(R) #21466wordingneutralT1-LP Mustang GT350(R) spec line replaced with 2015+ model parameters including 5163cc engine, 3650 lbs curb weight, 315 tire size.
T1 Request to Classify Ford FP350S in T1-LP #25341cars addedneutralFord Mustang FP350S (2018) classified in T1-LP at 3600 lbs with 18×11 wheels and 315 tires.
T1 Amendment to Request #25555 #25556wordingneutralT1 suspension rules clarified: spherical bearings and bushings now explicitly permitted, alternate control arms allowed.
T1 Request to balance 996 v 997 T1 weight #25658weightfasterT1 Porsche 996 drops 200 lbs to 3000; 996 GT3 Cup drops 150 lbs to 3000; 997 drops 50 lbs to 3100.
T1 Request to Add PDK Transmission to 997 Porsche Spec Line #25668wordingneutralPorsche 997 T1 Maximum now allows OEM PDK transmission alongside existing drivetrain options.
T1 T1 World Challenge/Grand AM Spec Cars #25687weightslowerT1 Acura NSX Turbo World Challenge weight to 3100 lbs, restrictor to 44mm.
T1 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.
T3 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.
T3 Request to update SpecE46 Appendix N. with 2019 Rules #25722wordingneutralT3 BMW SpecE46 rules reference updated from Appendix N to Version 2.6 Effective Jan 1, 2019.
T3 Request Alternative Nissan Brake Parts - 350Z #25747suspension & brakesneutralT3 Nissan 350Z Track/Touring/Standard/Nismo 03-08 permitted to use Nissan brake kit part number 41000-BRKIT.
T3 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.
T3 Clarify Subframe Bushings Permitted for T2-T4 #25800wordingneutralT2-T4 subframe bushings may now be replaced with non-spherical bushings of any material.
T3 Additional weight adjustments for T3 cars T3 weight loss #25803weightfasterT3 field loses 50 lbs across 27 cars including Acura TL, BMW 335i, Camaro, Mustang, Miata, RX-8, 370Z, WRX.
T3 Request for Alternate EcoBoost Mustang Brakes #25813suspension & brakesslowerT3 Ford Mustang EcoBoost gains Ford Motorsports or Brembo brake kit options, +100 lb.
T3 Request to Add the FR-S/86 and BRZ Spec Lines to T3 #25888weightfasterT3 FR-S/86 and BRZ: wheels to 17x9, tires to 255, weight to 2750 lbs.
T3 Request to Clarify BMW SpecE46 Tire Verbiage #26027tyres & wheelsneutralT3 BMW SpecE46 now permits any DOT tire up to 225 width as alternate to spec tire.
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 T1" is the class's best as a share of T1'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 T1'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.