Lap times across years say as much about the weather as the class. % of AS is each class's best lap as a share of AS's on the same day, so the conditions drop out: 100% is level, less is quicker, and a move in it is the class getting faster or slower against the field.
Closest to the field:AS 100.0% of AS Andy McDermid, Daytona International Speedway Runoffs 2015 race · T4 102.3% of AS Alex Lozano, Road America Runoffs 2025 race · SM 104.5% of AS Michael Carter, Sonoma Raceway Runoffs 2018 race · FA 81.2% of AS James French, Indianapolis Motor Speedway Runoffs 2021 qualifying
AST4SMFAsolid race · dashed qualifying · slower is lower
AST4SMFAsolid race · dashed qualifying · each class's best lap as a share of AS's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker
2:26.911Andrew McDermid · fastest of 8 · top 5 within 3.4s+0.119s (+0.08%)
2:28.471Andrew McDermid · fastest of 8 · top 5 within 2.4s-0.761s (-0.51%)
151.0Andrew McDermid-0.6 mph (-0.4%)
2:35.876Matt Spicuzzi · fastest of 12 · top 5 within 2.4s+2.920s (+1.91%)
2:35.757Matt Spicuzzi · fastest of 12 · top 5 within 2.7s+3.124s (+2.05%)
127.6Matt Spicuzzi-6.0 mph (-4.5%)
+7.286squal +8.965s
104.9%qual 106.1%
2:42.173Brett Kowalski · fastest of 34 · top 5 within 0.3s-0.938s (-0.58%)
2:42.725Francisco Barroso · fastest of 35 · top 5 within 0.2s-1.705s (-1.04%)
119.6Wyatt Couch+0.3 mph (+0.3%)
+14.254squal +15.262s
109.6%qual 110.4%
2:02.513Dudley Fleck · fastest of 9 · top 5 within 6.9s+1.590s (+1.31%)
2:03.334James French · fastest of 10 · top 5 within 1.4s+0.680s (+0.55%)
158.6John McAleer+1.5 mph (+1.0%)
-25.137squal -24.398s
83.1%qual 83.4%
48 rule changes (AS: 13, T4: 26, SM: 2, FA: 7)9 cars added · 6 weight · 5 induction · 5 suspension & brakes · 4 engine · 3 tyres & wheels · 2 removed · 1 aero · 5 wording · 8 other · AS Camaro 16+ Spec Line: 1LE front splitter kit permitted, belt tensioner and motor mount parts allowed, spark plug position defined. · AS class adds Pirelli P Zero Trofeo Track as permitted tyre option for competition. · AS class rear trailing arms no longer required to maintain stock length, only to locate rear axle. · AS Ford Mustang GT 4.6L 4-valve regains allowance, minimum weight 3200 lbs. · AS Ford Mustang Coupe GT 05-14 Gen3 Coyote minimum weight increases from 3100 to 3400 lbs. · FA sealed engine teardown: competitors no longer pay reassembly and resealing costs; stewards handle inspection per section 9.3.42. · SM/SMX Mazda rear toe link part number revised from 0000-04-5361426 to 0000-04-5361. · AS GM LM7 5.3L must use full prep Holley carburetor as described in 9.1.6.D.c.1, not specifically 4776. · FA Mazda 13B rotary permits one 48mm or 50mm dual-throat carburetor with 41.5mm venturi or fuel injection with 36mm SIR. · AS EFI engine build sheets add dry sump, header, camshaft, and timing chain tensioner options for LS, LT1, Ford, and Mopar engines. · AS LT1 Camaro engine build sheet added with full specs; LT1 weight 3200 lbs, GTO tire to 275, Mustang weight to 3525 lbs, oil catch tanks now required. · SM/SMX part number 0000-10-6900 replaced with 0000-06-5016-KT in GCR 9.1.7.C.1.j.1.c. · AS Spec Lines reorganized for 2026; detailed chassis, engine, weight, wheelbase, tire and brake specifications moved to main rules and engine build sheets. · AS GM LM7 5.3L gains Edelbrock 71187 intake manifold, MSD 6014 ignition box, Holly 4776 carb option under full prep spec line. · Pro Formula Mazda allows lower intake manifold unrestricted, throttle body increased to 80mm maximum. · T2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously only spherical bearings permitted. · AS Ford Mustang and Mercury Capri with Restricted Prep engines get 61 mm restrictor, down from 64 mm. · FA MZR may use Noor P/N 0088-8-00 intake with AT Power runners; aluminum spacer minimum length 2.200 inches required. · FA Formula 1000 motorcycle-based 4-cycle engine loses maximum compression ratio 14.5:1 limit; current rules apply. · FA Formula 1000 allows carbon fiber external panels, forward-facing gaps, raises undertray to 125mm, allows eight 75×125mm rub blocks, widens diffuser to 110cm with 75mm radius transitions. · T2, T3, T4 now allow under-dash electronics relocation for access after roll cage installation. · T4 Performance clarified: 1-piece alternative rotors permitted only at sizes listed in spec line; alternate brake kits may use matching 1-piece rotors. · AS Ford Mustang GT 94-04 Restricted Prep Engine now permits Ford Motorsport M-6250-F303 camshaft. · AS Cadillac CTS-V 04-07 Restricted Prep minimum weight drops to 3400 lbs. · FA class adds USF Pro 2000 car as permitted model. · T3 and T4 Mazda MX-5 Miata add permitted gearset kit PT#0000-02-6100 to Notes. · T4 MX-5 Miata 19-24 and 16-18, T3 MX-5 16-18 and Global Cup ND1/ND: discontinued DG Motorsports hardtop part #0000-07-5901 removed from permitted list.showhide
AS 2016+ Camaro Spec Line Full Prep #39646otheraddedAS Camaro 16+ Spec Line: 1LE front splitter kit permitted, belt tensioner and motor mount parts allowed, spark plug position defined.
AS Consideration of Pirelli P Zero Trofeo Track for AS Competition #40495tyres & wheelsaddedtyres & wheelsAS class adds Pirelli P Zero Trofeo Track as permitted tyre option for competition.
T4 02-06 R53 Mini Cooper Hotchkins Rear Camber Arms #40677suspension & brakes
AS Change in 9.1.6.D.4.d.5 in Suspension Mounting Points #40094suspension & brakesfastersuspension & brakesAS class rear trailing arms no longer required to maintain stock length, only to locate rear axle.
AS Re-Add 4.6L 4v 96-04 Mustang Cobra #40239cars addedaddedAS Ford Mustang GT 4.6L 4-valve regains allowance, minimum weight 3200 lbs.
AS Errors and Omissions #40532weightslowerweightAS Ford Mustang Coupe GT 05-14 Gen3 Coyote minimum weight increases from 3100 to 3400 lbs.
FA Update sealed engine teardown section #40621wordingaddedFA sealed engine teardown: competitors no longer pay reassembly and resealing costs; stewards handle inspection per section 9.3.42.
AS Clarification for LM7 Holley Carburetor #40167wordingwordingAS GM LM7 5.3L must use full prep Holley carburetor as described in 9.1.6.D.c.1, not specifically 4776.
FA Motor Classification #40175cars addedaddedFA Mazda 13B rotary permits one 48mm or 50mm dual-throat carburetor with 41.5mm venturi or fuel injection with 36mm SIR.
T4 2003 Honda Civic Si Classification #39999cars added
AS Header Information Update for EFI Engine Build Sheets #39886engineaddedengineAS EFI engine build sheets add dry sump, header, camshaft, and timing chain tensioner options for LS, LT1, Ford, and Mopar engines.
AS Errors and Omissions #39933otherfasterAS LT1 Camaro engine build sheet added with full specs; LT1 weight 3200 lbs, GTO tire to 275, Mustang weight to 3525 lbs, oil catch tanks now required.
SM Part Number Change Request #39914otherunclearSM/SMX part number 0000-10-6900 replaced with 0000-06-5016-KT in GCR 9.1.7.C.1.j.1.c.
AS Re-Organization of AS Spec lines for 2026 #39887wordingwordingAS Spec Lines reorganized for 2026; detailed chassis, engine, weight, wheelbase, tire and brake specifications moved to main rules and engine build sheets.
T4 ND MX-5 Spec Line Rewrite Request #39802weight -100 lbs
AS Edelbrock manifold (& timing kit) to Chevy LS Spec Lines Request #39055cars addedaddedAS GM LM7 5.3L gains Edelbrock 71187 intake manifold, MSD 6014 ignition box, Holly 4776 carb option under full prep spec line.
FA Pro Mazda Classification and Performance Enhancement Proposal #39411enginefasterenginePro Formula Mazda allows lower intake manifold unrestricted, throttle body increased to 80mm maximum.
T4 Allow Alt Bushing Material in Toe Links #39607suspension & brakesaddedsuspension & brakesT2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously only spherical bearings permitted.
AS Restrictor Plate Change for Gen 2 Ford Coyote Engine #39501inductionslowerinductionAS Ford Mustang and Mercury Capri with Restricted Prep engines get 61 mm restrictor, down from 64 mm.
FA Alternate Intake Manifold for MZR #38223inductionaddedinductionFA MZR may use Noor P/N 0088-8-00 intake with AT Power runners; aluminum spacer minimum length 2.200 inches required.
FA Engine Compression Rule Change Request #39302enginefasterengineFA Formula 1000 motorcycle-based 4-cycle engine loses maximum compression ratio 14.5:1 limit; current rules apply.
FA Change Formula 1000 allowances #39608aerofasteraeroFA Formula 1000 allows carbon fiber external panels, forward-facing gaps, raises undertray to 125mm, allows eight 75×125mm rub blocks, widens diffuser to 110cm with 75mm radius transitions.
T4 Alternate Placement of Fuse Panel and Electronics Request #39370otheraddedT2, T3, T4 now allow under-dash electronics relocation for access after roll cage installation.
T4 Clarify T4 Brake Rotor Allowance #39503wordingwordingT4 Performance clarified: 1-piece alternative rotors permitted only at sizes listed in spec line; alternate brake kits may use matching 1-piece rotors.
AS 1994 Mustang Spec Line Request #39104engineaddedengineAS Ford Mustang GT 94-04 Restricted Prep Engine now permits Ford Motorsport M-6250-F303 camshaft.
T4 ND Spec Lines Wrong PT#'s #39170removedremovedT4 MX-5 Miata 19-24 and 16-18, T3 MX-5 16-18 and Global Cup ND1/ND: discontinued DG Motorsports hardtop part #0000-07-5901 removed from permitted list.
2:26.792Andrew McDermid · fastest of 11 · top 5 within 3.9s+0.214s (+0.15%)
2:29.232Gregory Eaton · fastest of 10 · top 5 within 4.0s+2.803s (+1.91%)
151.5Andrew McDermid+1.9 mph (+1.3%)
2:32.956Matt Spicuzzi · fastest of 10 · top 5 within 3.8s-1.474s (-0.95%)
2:32.633Alex Lozano · fastest of 10 · top 5 within 4.3s-1.575s (-1.02%)
133.7Alex Lozano+4.4 mph (+3.4%)
+3.401squal +6.164s
102.3%qual 104.2%
2:43.111Bobby Gossett · fastest of 32 · top 5 within 0.3s+2.005s (+1.24%)
2:44.430Kyle Greenhill · fastest of 28 · top 5 within 0.3s+2.944s (+1.82%)
119.3Francisco Barroso-0.6 mph (-0.5%)
+15.198squal +16.319s
110.2%qual 111.1%
2:00.923Hans Peter · fastest of 12 · top 5 within 2.4s-0.637s (-0.52%)
2:02.654Hans Peter · fastest of 11 · top 5 within 3.1s+0.864s (+0.71%)
157.0Shane Kennett-3.0 mph (-1.9%)
-26.578squal -25.869s
82.2%qual 82.4%
47 rule changes (AS: 11, T4: 29, SM: 4, FA: 3)7 cars added · 7 weight · 5 tyres & wheels · 4 engine · 1 aero · 1 induction · 1 removed · 11 wording · 10 other · T2, T3, T4 spec table header changed from T2 to ET. · AS Ford Mustang GT 5.0 2018- minimum weight reduced to 3525 lbs. · FA Ligier JS F3 front tires change to Hoosier 240/580R13 MS, rear to 300/590R13 MS. · AS Ford Mustang GT 05-14 Restricted Prep Engine gains additional gear ratio option: 3.66, 2.43, 1.69, 1.32, 1.00, .65. · SMX drivers must submit data acquisition files on time or face suspension and $250 fine. · SMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fines, level 2 and 4 may carry $500 fines. · AS Ford Mustang GT 5.0L 15-17 flat plate restrictor reduces from 67mm to 64mm. · AS LS1/LS6 intakes added for 5.3L truck engine: part numbers 12561269 and 88894095. · SM tire marking rules clarified: one Hoosier SM 7.5 P205/50/ZR17 set per Super Tour weekend, impound after first dry session, damaged tires may be replaced with used tires only. · AS Flotek head value seat cutting dimensions figure updated for consistency. · AS class notes cleaned: fuel cell and ECM specifications removed from multiple Camaro, Firebird, Challenger and Mustang variants. · AS removes 'Any ECM maybe used' note from five Cadillac and Chevrolet/Pontiac V8 Restricted Prep models. · FA Formula Renault 2.0 (10-17) spec notes clarified: engine sealed, manual compliance required, tyre choice unrestricted, no alterations except repairs. · FA adds Formula Regional European Championship Tatuus F.3 T-318 or FR-19 as spec line car in Table 2. · Ford SCCA Club Spec Mustang added to T3 at 3350 lbs; Mazda SCCA Club Spec MX-5 added to T4 at 2500 lbs. · AS Ford Mustang and Cobra Coyote engine restrictor increases to 80mm from 67mm or 64mm. · AS Mustang GT 05-14 Restricted loses 300 lbs engine; 15-17 and 2018+ models lose 61mm and 60mm restrictors respectively. · AS class: multiple American muscle cars gain additional allowed gear ratio options across model years and prep levels. · AS LS-engine cars gain ECU freedom: CTS-V, Camaro, Firebird (70–02) and Camaro SS may use any ECM. · T2, T3, T4: nine, nine, and thirty-seven expired spec lines removed effective 2025-01-01. · SMX OE instrument cluster must stay unmodified and connected; aftermarket dash allowed if wiring only re-routed; alternate gauges now permitted; foot pedal comfort mods allowed without relocation. · T2, T3 Mustang spec lines remove redundant driveshaft allowance notes across six model year ranges. · T2, T3, T4 fuel cell installations may omit charcoal canisters, emissions valves, and sensors. · T2, T3, T4 brake specifications clarified: 2-piece rotors allowed in T2 within 5% OE diameter, T3 within 2% OEM diameter. · T2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors. · Porsche Spec Boxster moves to T4, minimum weight 2750 lbs, ineligible for Runoffs until 3 Super Tour events. · T4 BMW 320i Spec Line: Turner Motorsports intercooler #024703TMS02 now allowed. · 2005 Cadillac CTS 3.6L 6-speed manual classified in T3 Spec.showhide
T4 Incorrect Touring Heading #38451wordingwordingT2, T3, T4 spec table header changed from T2 to ET.
AS RE: Previous Letter 37695 Update #38245weight -75 lbsfasterweightAS Ford Mustang GT 5.0 2018- minimum weight reduced to 3525 lbs.
FA Ligier JS F3 Tire Choice #38434tyres & wheelstyres & wheelsFA Ligier JS F3 front tires change to Hoosier 240/580R13 MS, rear to 300/590R13 MS.
AS Errors and Omissions #38234otheraddedAS Ford Mustang GT 05-14 Restricted Prep Engine gains additional gear ratio option: 3.66, 2.43, 1.69, 1.32, 1.00, .65.
SM SMX Data Submission - Penalties #38248otheraddedSMX drivers must submit data acquisition files on time or face suspension and $250 fine.
SM Committee) SMX Penaly Clarification updated language #38337wordingwordingSMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fines, level 2 and 4 may carry $500 fines.
AS Errors and Omission #38055inductionslowerinductionAS Ford Mustang GT 5.0L 15-17 flat plate restrictor reduces from 67mm to 64mm.
AS Request to Add LS1/LS6 Intakes for 5.3L Truck Engine EnO #38197cars addedaddedAS LS1/LS6 intakes added for 5.3L truck engine: part numbers 12561269 and 88894095.
SM Clarify Tire Marking Regs #38005wordingwordingSM tire marking rules clarified: one Hoosier SM 7.5 P205/50/ZR17 set per Super Tour weekend, impound after first dry session, damaged tires may be replaced with used tires only.
T4 Correct Ring and Pinion Ratio to T3, Sorry I Mean T4 3.7 V6 Stang #38041wording
AS Flotek Head Plunge Cut Inconsistencies #37502wordingwordingAS Flotek head value seat cutting dimensions figure updated for consistency.
AS Notes clean up #37693wordingwordingAS class notes cleaned: fuel cell and ECM specifications removed from multiple Camaro, Firebird, Challenger and Mustang variants.
AS Race memo #37902wordingwordingAS removes 'Any ECM maybe used' note from five Cadillac and Chevrolet/Pontiac V8 Restricted Prep models.
FA Update Formula Renault 2.0 spec line notes #37853wordingwordingFA Formula Renault 2.0 (10-17) spec notes clarified: engine sealed, manual compliance required, tyre choice unrestricted, no alterations except repairs.
FA Classify FR European Championship car as spec line car in Table 2 #37658cars addedaddedFA adds Formula Regional European Championship Tatuus F.3 T-318 or FR-19 as spec line car in Table 2.
T4 Request to Classify Club Spec in Appropriate Touring Classes #37523cars addedaddedFord SCCA Club Spec Mustang added to T3 at 3350 lbs; Mazda SCCA Club Spec MX-5 added to T4 at 2500 lbs.
AS Increase Coyote Engine Restrictor to 80mm #36177enginefasterengineAS Ford Mustang and Cobra Coyote engine restrictor increases to 80mm from 67mm or 64mm.
AS Performance Pack for 2015+ Mustang #36867enginefasterengineAS Mustang GT 05-14 Restricted loses 300 lbs engine; 15-17 and 2018+ models lose 61mm and 60mm restrictors respectively.
AS Gear Ratios #37131otheraddedAS class: multiple American muscle cars gain additional allowed gear ratio options across model years and prep levels.
AS ECU specs for LS engine #37208engineaddedengineAS LS-engine cars gain ECU freedom: CTS-V, Camaro, Firebird (70–02) and Camaro SS may use any ECM.
T4 Remove spec lines that have expired #37269removedremovedT2, T3, T4: nine, nine, and thirty-seven expired spec lines removed effective 2025-01-01.
SM E&O SMX Regs 9.1.7.1.D.5.u-.w #37070wordingwordingSMX OE instrument cluster must stay unmodified and connected; aftermarket dash allowed if wiring only re-routed; alternate gauges now permitted; foot pedal comfort mods allowed without relocation.
T4 Redundant Verbiage Regarding Mustang Spec Lines for Driveshaft #36484wordingwordingT2, T3 Mustang spec lines remove redundant driveshaft allowance notes across six model year ranges.
T4 R53 Mini Cooper S Weight Reduction Request #36612weight
T4 Move Spec Boxster to T4 #37158cars addedaddedPorsche Spec Boxster moves to T4, minimum weight 2750 lbs, ineligible for Runoffs until 3 Super Tour events.
2:26.578Gregory Eaton · fastest of 18 · top 5 within 2.6s-0.467s (-0.32%)
2:26.429Gregory Eaton · fastest of 18 · top 5 within 2.5s-1.239s (-0.84%)
149.6Gregory Eaton+0.4 mph (+0.3%)
2:34.430Matt Spicuzzi · fastest of 15 · top 5 within 1.8s-2.973s (-1.89%)
2:34.208Alex Lozano · fastest of 14 · top 5 within 2.2s-3.673s (-2.33%)
129.3Alex Lozano-0.9 mph (-0.7%)
+7.779squal +7.852s
105.3%qual 105.4%
2:41.106Ethan Goulart · fastest of 49 · top 5 within 0.5s-1.103s (-0.68%)
2:41.486Brett Kowalski · fastest of 43 · top 5 within 0.3s-2.262s (-1.38%)
119.9Alex Bertagnoli-1.4 mph (-1.2%)
+15.057squal +14.528s
110.3%qual 109.9%
2:01.560Hans Peter · fastest of 13 · top 5 within 2.0s-2.714s (-2.18%)
2:01.790Dudley Fleck · fastest of 12 · top 5 within 3.3s-2.956s (-2.37%)
160.0Brandon Schwarz+9.4 mph (+6.3%)
-24.639squal -25.018s
83.2%qual 82.9%
43 rule changes (AS: 11, T4: 28, SM: 4)10 cars added · 8 weight · 5 suspension & brakes · 3 engine · 2 aero · 1 induction · 1 removed · 1 tyres & wheels · 4 wording · 8 other · AS Mustang GT 05-14 Restricted Prep and 2018- gain alternate transmission ratio options. · SMX Spec MX-5 camera requirement: non-functioning recorder now will instead of may warrant penalty or disqualification. · SM and SMX must run latest AIM Data Logger Spec MX-5 ECU Protocol, effective 2024-09-01. · SMX Mazda MX-5 OE versus OEM definitions clarified in GCR section 9.1.7.1; wording change only. · SM and SMX now allow an alternate shifter bushing at the bottom of the shift lever. · T2 Mustang GT 5.0L 15-17 and 2018- now permit Track/Performance Package parts; T3 V6 15-17 clarified to allow Track/Performance package. · T2-T4 Ford Mustangs: remove 25 lb penalty for non-OEM driveshaft, clarify alternate driveshaft allowance. · Audi S4 (2000–2002) classified in T3 with 2671cc, 3400 lbs minimum weight, 38mm restrictor, allowing 800lb springs and intercooler. · AS adds 2018-23 Ford Mustang GT 5.0L at 3600 lbs, 275 tire, 60mm restrictor, optional Brembo front brakes. · AS Chevrolet Camaro 1LE (2016-) added with 3600 lbs minimum weight, 275 tires, 60mm restrictor, 345/338mm brakes. · AS Chevrolet/Pontiac Camaro & Firebird 82–92 5.7L LS1 classified: 3200 lbs, 13.1×1.27 disc brakes, 17 in max wheel, 65 mm restrictor, SLP intake lid permitted. · AS Chevrolet Camaro, Firebird, and Ford Mustang now permit Flo Tek cylinder heads in multiple generations. · T3 and T4 Mazda RX-8 may remove or disable factory oil injection system. · T2, T3, T4 driveshafts may use carbon fiber, aluminum, or steel; two-piece replaced with one-piece; non-OEM adds 25 lbs. · AS Camaro, Firebird 93-02 and GTO 04-06 add approved LS1 connecting rod part numbers to Notes. · AS Cadillac CTS-V, Chevy Camaro SS V8, Dodge Challenger, Ford Mustang GT 5.0L, Pontiac GTO allowed 11" wheels until 3/1/25. · Chevrolet Camaro, Pontiac Firebird 70–81 Full Prep classified in AS at 3400–3600 lbs with 108.0 wheelbase, specific head castings, and suspension modifications permitted. · AS class adds fuel cell location notes to multiple Cadillac, Chevrolet, Dodge and Ford models: cells within 24 inches of standard tank. · Chevrolet Camaro 6th gen Full Prep added to AS class at 3400 lbs base or 3600 lbs with built engine. · AS class: Ford Mustang GT 05-14 Restricted prep added; Cadillac CTS-V 04-07 to 3450 lbs; Camaro/Firebird variants reconfigured with weight and notes changes; Dodge Challenger 08-20 restrictor 76mm to 80mm; Ford Mustang variants updated wei… · T2, T3, T4 Spec Lines remove wheelbase requirement, add Required Restrictor specification. · T2 and T3 Nissan 370Z front brake rotors increase to 355×32 mm, rears to 350×20 mm. · T2, T3, T4 battery replacement no longer allows alternate manufacturer batteries within 10% OEM weight. · T4 now allows C-Spec touring cars to compete, in addition to existing B-Spec eligibility. · T2, T3, T4 spec lines expire 12/31/24; submit to appeal or cars are removed from class. · T3 Nissan 370Z now includes model years 2009–2022 with Nismo editions.showhide
AS Mustang transmission ratios #36662otheraddedAS Mustang GT 05-14 Restricted Prep and 2018- gain alternate transmission ratio options.
SM SMX Camera Rule Correction #36496wordingwordingSMX Spec MX-5 camera requirement: non-functioning recorder now will instead of may warrant penalty or disqualification.
SM Committee) AIM ECU Protocol #36556engineaddedengineSM and SMX must run latest AIM Data Logger Spec MX-5 ECU Protocol, effective 2024-09-01.
SM Committee) OE versus OEM Definitons #36608wordingwordingSMX Mazda MX-5 OE versus OEM definitions clarified in GCR section 9.1.7.1; wording change only.
SM Committee) Shifter Bushing #36611otheraddedSM and SMX now allow an alternate shifter bushing at the bottom of the shift lever.
T4 B8/8.5 Audi S4 T3 and T2 #36195cars addedaddedAudi S4 (2000–2002) classified in T3 with 2671cc, 3400 lbs minimum weight, 38mm restrictor, allowing 800lb springs and intercooler.
AS Request for Classification of 2018-2023 mustang In #35764cars addedaddedAS adds 2018-23 Ford Mustang GT 5.0L at 3600 lbs, 275 tire, 60mm restrictor, optional Brembo front brakes.
T4 Allow OEM Front Spoiler 06-08 Miata in T4 #35941aero
T4 R53 Mini Cooper S spec line request In #36056suspension & brakes
AS 6th gen Camaro limited prep #35733cars addedaddedAS Chevrolet Camaro 1LE (2016-) added with 3600 lbs minimum weight, 275 tires, 60mm restrictor, 345/338mm brakes.
AS Chevrolet/Pontiac Camaro & Firebird (82-92) 5.7L V8 LS1 Alum BLK #35825cars addedaddedAS Chevrolet/Pontiac Camaro & Firebird 82–92 5.7L LS1 classified: 3200 lbs, 13.1×1.27 disc brakes, 17 in max wheel, 65 mm restrictor, SLP intake lid permitted.
AS Full Prep Head #35891engineaddedengineAS Chevrolet Camaro, Firebird, and Ford Mustang now permit Flo Tek cylinder heads in multiple generations.
T4 Allow T4 and T3 RX8 to Disable/Remove Factory Oil Inj. #35761engineaddedengineT3 and T4 Mazda RX-8 may remove or disable factory oil injection system.
T4 2023 ND2 Miata Classification and Allowances #35837weight
T4 Errors and Omissions for 06-09 VW Rabbit Rotor #35851suspension & brakes
T4 Driveshafts #35916weightslowerweightT2, T3, T4 driveshafts may use carbon fiber, aluminum, or steel; two-piece replaced with one-piece; non-OEM adds 25 lbs.
T4 GCR ERROR - letter not properly applied to GCR #35999weight
AS Restricted Prep Aftermarket Parts Request #35682otheraddedAS Camaro, Firebird 93-02 and GTO 04-06 add approved LS1 connecting rod part numbers to Notes.
AS Allowance of 11 #35824tyres & wheelsfastertyres & wheelsAS Cadillac CTS-V, Chevy Camaro SS V8, Dodge Challenger, Ford Mustang GT 5.0L, Pontiac GTO allowed 11" wheels until 3/1/25.
AS Request to Classify 1970-1981 Camaro and Firebird in AS #33659cars addedaddedChevrolet Camaro, Pontiac Firebird 70–81 Full Prep classified in AS at 3400–3600 lbs with 108.0 wheelbase, specific head castings, and suspension modifications permitted.
AS Fuel Cell 12 #34194otheraddedAS class adds fuel cell location notes to multiple Cadillac, Chevrolet, Dodge and Ford models: cells within 24 inches of standard tank.
AS Please Classify the 6th Gen Into AS. #35448cars addedaddedChevrolet Camaro 6th gen Full Prep added to AS class at 3400 lbs base or 3600 lbs with built engine.
AS spec lines #35713otherunclearAS class: Ford Mustang GT 05-14 Restricted prep added; Cadillac CTS-V 04-07 to 3450 lbs; Camaro/Firebird variants reconfigured with weight and notes changes; Dodge Challenger 08-20 restrictor 76mm to 80mm; Ford Mustang variants updated wei…
T4 Allow any 400lb rear spring in the RX8 #35433suspension & brakes
T4 370Z Brake Rotor Size Correction #35487suspension & brakessuspension & brakesT2 and T3 Nissan 370Z front brake rotors increase to 355×32 mm, rears to 350×20 mm.
T4 More Car Lightening Stuff #35319wordingremovedT2, T3, T4 battery replacement no longer allows alternate manufacturer batteries within 10% OEM weight.
T4 Inclusion of B-C spec cars in T4 #35374cars addedaddedT4 now allows C-Spec touring cars to compete, in addition to existing B-Spec eligibility.
T4 T2-T4 Set expiration dates on spec lines #35378wordingremovedT2, T3, T4 spec lines expire 12/31/24; submit to appeal or cars are removed from class.
T4 Mazda MX-5 ND1 Spec Line Request #34232weight +50 lbs
T4 BRZ/FRS/86 Spring Allowance #35038suspension & brakes
2:03.082Daniel Richardson · fastest of 11 · top 5 within 2.2s+0.920s (+0.75%)
2:04.120Gregory Eaton · fastest of 9 · top 5 within 3.0s-0.458s (-0.37%)
154.6James Jost+3.7 mph (+2.5%)
2:10.514Devin Anderson · fastest of 24 · top 5 within 0.5s+0.937s (+0.72%)
2:11.962Devin Anderson · fastest of 23 · top 5 within 0.1s-13.481s (-9.27%)
127.8Raymond Blethen+0.5 mph (+0.4%)
+7.842squal +7.432s
106.3%qual 106.0%
2:14.986Danny Steyn · fastest of 52 · top 5 within 0.1s+0.322s (+0.24%)
2:16.229Julian DaCosta · fastest of 46 · top 5 within 0.3s-2.878s (-2.07%)
120.3Jim Drago+1.1 mph (+0.9%)
+12.109squal +11.904s
109.8%qual 109.7%
32 rule changes (AS: 4, T4: 20, SM: 1, FA: 7)7 weight · 4 cars added · 4 suspension & brakes · 2 induction · 2 tyres & wheels · 1 aero · 7 wording · 5 other · AS crate motor part number specification clarified; both CT400 P/N-19370604 and 19370604 engine assemblies permitted for GM vehicles. · AS Ford Mustang GT 5.0L (15-17) Restricted maximum wheel diameter increases to 19.0 inches. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front upper control arms; SPC-66045 spec part removed. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 now allows alternate front brake calipers with adaptor brackets for component compatibility. · Mazda RX-8 T3 and T4 transmission and final drive pairing requirement removed; T4 gains Mazdaspeed radiator, spring kit, restrictor, spoiler, air dam. · T3 BMW 320i 14–15 gains aftermarket intercooler; T4 BMW 320i 14–15 loses it. · T3 and T2 Pontiac Solstice GXP 07-09 minimum ride height set to 3 inches. · FA Pro Formula Mazda front wheel width minimum raised to 10 inches, rear to 14 minimum and 15 maximum. · FA Pro Formula Mazda maximum bodywork width behind front wheels increases to 51.97 inches, from 51.17 inches. · FA MSR Formula Mazda FMzR added to Table 2 classification. · T3 BMW 320I now permitted to use an aftermarket intercooler. · T2 and T3 Mustang 11-14 may remove upper grille fog lights, replace with mesh or screen. · Unable to complete: rule text does not show the spec line to be added to FA Table 1 for BDA displacement. · SM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore. · T5 touring class added; T2-T5 cars may race one class up; T5 maximum tyre width 225 with minimum aspect ratio 45. · T2-T5 Touring front and rear suspension maximum negative camber clarified to 3.5 degrees. · Formula Renault 2.0 (10-17) reclassified from FX to FA spec line; minimum weight reduced 1300 to 1280 lbs, restrictor removed. · FA Swift 016 2.3L Mazda Duratec restrictor increases to 32mm, minimum weight drops to 1420 lbs. · Pro Formula Mazda allows street or bridge port, unmodified OEM lower intake manifold, 70mm throttle body, wing height to 99cm, bodywork width to 132cm. · T3 Subaru BRZ 2022- minimum weight rises 225 lbs to 2975; spring rate to 1000 F/R; tower brace, control arms, intake allowed; brake parts penalty removed.showhide
T4 Inclusion of similar car. (CLK 320) #34626other
AS Crate Motor Part Numbers #32944wordingwordingAS crate motor part number specification clarified; both CT400 P/N-19370604 and 19370604 engine assemblies permitted for GM vehicles.
AS Request wheel size change #33007tyres & wheelsfastertyres & wheelsAS Ford Mustang GT 5.0L (15-17) Restricted maximum wheel diameter increases to 19.0 inches.
AS Alternative Upper Front Control Arms for Dodge Challenger #33352wordingwordingAS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front upper control arms; SPC-66045 spec part removed.
AS Front Brake Caliper Adapters for Dodge Challenger #33353otherotherAS Dodge Challenger 5.7L/6.1L/6.4L V8 now allows alternate front brake calipers with adaptor brackets for component compatibility.
T4 Rules Clarification for Mazda RX8 Spec Line #34395wordingwordingMazda RX-8 T3 and T4 transmission and final drive pairing requirement removed; T4 gains Mazdaspeed radiator, spring kit, restrictor, spoiler, air dam.
T4 rule book corrections #34437otheraddedT3 BMW 320i 14–15 gains aftermarket intercooler; T4 BMW 320i 14–15 loses it.
T4 Ride Height Correction for the T3 Solstice. #34615suspension & brakessuspension & brakesT3 and T2 Pontiac Solstice GXP 07-09 minimum ride height set to 3 inches.
T4 2002-2006 Mini Cooper S R53 Spec Line Request #34336weight -50 lbs
FA Simplify Pro Formula Mazda wheel allowance #34190tyres & wheelsslowertyres & wheelsFA Pro Formula Mazda front wheel width minimum raised to 10 inches, rear to 14 minimum and 15 maximum.
T4 96-01 Audi a4 2.8 Spring Rate #34217suspension & brakes
FA E&O - Correct Pro Formula Mazda spec line dimensional equivalent #34085wordingwordingFA Pro Formula Mazda maximum bodywork width behind front wheels increases to 51.97 inches, from 51.17 inches.
FA Add new spec line for MSR Formula Mazda FMzR to Table 2 #34139cars addedaddedFA MSR Formula Mazda FMzR added to Table 2 classification.
T4 Request to Classify 2004-2008 Acura TSX in T4 #33590cars added
T4 Mustang OEM Grill Request #33333aeroaddedaeroT2 and T3 Mustang 11-14 may remove upper grille fog lights, replace with mesh or screen.
T4 Mazda OEM LSD was letter 32655 typo #33666wording
FA BDA Displacement #33431otherunclearUnable to complete: rule text does not show the spec line to be added to FA Table 1 for BDA displacement.
SM BOP for NB1 and NB2 #32309weightslowerweightSM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore.
T4 Allowable Springs and Sway Bars for 06-11 Civic si Spec Line #33294suspension & brakes
T4 Touring (T2-T5) Category #33617cars addedaddedT5 touring class added; T2-T5 cars may race one class up; T5 maximum tyre width 225 with minimum aspect ratio 45.
T4 ENO 9.1.9.2.D.1.e.1.a. #33651wordingwordingT2-T5 Touring front and rear suspension maximum negative camber clarified to 3.5 degrees.
FA Reclassify 2010-2017 Formula Renault 2.0 as a spec line car in FA #33395weightfasterweightFormula Renault 2.0 (10-17) reclassified from FX to FA spec line; minimum weight reduced 1300 to 1280 lbs, restrictor removed.
FA Change Swift 016 2.3L restrictor size and minimum weight #33472induction -30 lbsfasterinductionFA Swift 016 2.3L Mazda Duratec restrictor increases to 32mm, minimum weight drops to 1420 lbs.
T4 Mazda OEM LSD was letter 32655 #32933weight -25 lbs
FA Pro Formula Mazda Dimension E&O #33160wordingwordingPro Formula Mazda allows street or bridge port, unmodified OEM lower intake manifold, 70mm throttle body, wing height to 99cm, bodywork width to 132cm.
T4 Another 2022 BRZ/86 T3 request #32945weight +225 lbsslowerweightT3 Subaru BRZ 2022- minimum weight rises 225 lbs to 2975; spring rate to 1000 F/R; tower brace, control arms, intake allowed; brake parts penalty removed.
2:02.162Kurt Rezzetano · fastest of 13 · top 5 within 2.3s-0.776s (-0.63%)
2:04.578Gregory Eaton · fastest of 11 · top 5 within 2.9s+0.678s (+0.55%)
150.9James Jost-3.0 mph (-2.0%)
2:09.577John Heinricy · fastest of 18 · top 5 within 0.7s-1.680s (-1.28%)
2:25.443John Heinricy · fastest of 18 · top 5 within 2.5s+14.484s (+11.06%)
127.4Nick Leverone-1.5 mph (-1.2%)
+20.865squal +7.415s
116.7%qual 106.1%
2:14.664Danny Steyn · fastest of 60 · top 5 within 0.2s+0.112s (+0.08%)
2:19.107Travis Wiley · fastest of 58 · top 5 within 0.9s+2.648s (+1.94%)
119.2Jonathan Neudorf-0.6 mph (-0.5%)
+14.529squal +12.502s
111.7%qual 110.2%
1:44.703Chip Romer · fastest of 7 · top 5 within 4.0s+3.158s (+3.11%)
1:48.507Alex Mayer · fastest of 4 · top 4 within 4.2s+5.400s (+5.24%)
154.6Austin Hill-1.4 mph (-0.9%)
-16.071squal -17.459s
87.1%qual 85.7%
46 rule changes (AS: 9, T4: 29, SM: 1, FA: 7)6 weight · 5 cars added · 5 suspension & brakes · 5 tyres & wheels · 4 engine · 1 aero · 1 induction · 1 removed · 12 wording · 6 other · AS adds Hoosier W2 wet tyre option alongside R7, R6, WET/H20. · AS Dodge Challenger 08-20 gains two transmission ratio options: 2.97–0.50 or 2.26–0.63. · AS Cadillac CTS-V 6.0L V8 Restricted Prep removes 295 tire size 50 lb penalty. · FA Ligier JS F3 must comply with FR Americas rules; competitors need current FR Americas Championship Sporting Regulations, Onroak manual, and HPD engine specs. · FA sealed engines now require full inspection by stewards; competitor pays all reassembly and resealing costs. · FA Formula Lites FL15 and FR Americas Ligier JS F3 engine sealing requirements clarified with regulatory references. · T2-T4 Touring cars with alternative springs now permitted to use performance top hats with spherical bearings on shocks and struts. · FA: transverse gearbox shafts prohibited except final drive and motorcycle gearbox in Formula 1000. · FA Swift 016 2.5 liter aero spec now references 2.3 liter notes instead of N notes. · SM Majors must run authorized Penske shock and mount; Regional competitors not required until further evaluation. · T2-T4 touring cars model year 2018+ may use aftermarket ECU with 75 lb weight penalty via spec line adjustment. · FA Pro Formula Mazda now allows street port or bridge port; porting was previously not permitted. · T2-T4 grill opening removal for cooling permitted without 16 square inch limit; mesh shape must match factory. · T3 Spec Lines: Subaru BRZ TS (13-21) now listed as 'Subaru BRZ, BRZ TS (13-21)'. · FA adds Honda K20Z3 2.0L at 1350 lbs and Mazda MZR 2.0L at 1300 lbs; removes 4A-GE 1.8L and MZR 2.0L from Table 2; raises 1615cc baseline to 1250 lbs. · SMG Long Tube Headers: Borla PN 17237 discontinued, approved alternatives American Racing MT3-05134300LSNC or Kooks PN 11312000. · AS Mercury Capri 79-86 removed as separate spec line, merged into Ford Mustang 79-93 spec line. · AS Spec Mustang SMG Restricted Prep removes 3.73 gear ratio and 355/300 brake disc sizes. · AS Camaro, Firebird, Mustang full prep engines: alternate GM and Ford Performance cylinder heads permitted regionally with Allstar restrictor ALL26180. · T2, T3, T4 clarify grill opening removal limited to 16 square inches for radiator cooling; mesh shape must be retained. · T2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted. · T2, T3, T4: clarified that 'permitted' or 'allowed' parts in spec lines are alternatives to category rule allowances, not replacements. · T4 adds 2014 VW Jetta 1.8T TSI to Spec Lines. · AS Chevrolet/Pontiac Camaro & Firebird 93-02 gains BMR AA004 or UMI 2310 adjustable front upper control arms. · AS Pontiac GTO 04-06 Restricted Prep minimum weight rises: LS1 to 3300 lbs, LS2 to 3350 lbs on 295 tires.showhide
AS Request to add Hoosier W2 #33031tyres & wheelsaddedtyres & wheelsAS adds Hoosier W2 wet tyre option alongside R7, R6, WET/H20.
AS correction of Dodge Challenger specification line #33151cars addedaddedAS Dodge Challenger 08-20 gains two transmission ratio options: 2.97–0.50 or 2.26–0.63.
T4 Request Wider Wheels for Hyundai Tiburon #32536tyres & wheels
FA Update FR Americas rulebook requirement #32491wordingwordingFA Ligier JS F3 must comply with FR Americas rules; competitors need current FR Americas Championship Sporting Regulations, Onroak manual, and HPD engine specs.
FA Clarify verification of sealed engine compliance #32522wordingwordingFA sealed engines now require full inspection by stewards; competitor pays all reassembly and resealing costs.
FA Clarify Formula Lites and FR Americas sealed engine requirement #32523wordingwordingFA Formula Lites FL15 and FR Americas Ligier JS F3 engine sealing requirements clarified with regulatory references.
T4 Request to Add Spec Line for 2004-2009 Mazda3 i 2.0 #32395weight
T4 Request Alternate Front & Rear Strut/Shock Top Hats #32452suspension & brakesaddedsuspension & brakesT2-T4 Touring cars with alternative springs now permitted to use performance top hats with spherical bearings on shocks and struts.
FA E&O FA Transmission section #32251wordingwordingFA: transverse gearbox shafts prohibited except final drive and motorcycle gearbox in Formula 1000.
FA E&O Swift 016 2.5 liter Aero column #32363wordingwordingFA Swift 016 2.5 liter aero spec now references 2.3 liter notes instead of N notes.
SM Update GCR Section 9.1.7.3.A.1. #32217wordingwordingSM Majors must run authorized Penske shock and mount; Regional competitors not required until further evaluation.
T4 Request to Allow the Use of Aftermarket ECU's in Touring #31067engineaddedengineT2-T4 touring cars model year 2018+ may use aftermarket ECU with 75 lb weight penalty via spec line adjustment.
T4 Request JWT BSR Kit for 02-06 Nissan Sentra SE-R/Spec V #31685other
T4 Please Confirm Touring 4 (98-00) BMW 323 is E46 generation #31972other
T4 RX-8 Spring Part Numbers (E&O) #32151suspension & brakes
FA Closing the Gap #31934enginefasterengineFA Pro Formula Mazda now allows street port or bridge port; porting was previously not permitted.
T4 Reply to letter #31486/29879 T2-T4 Grill openings #31935aerofasteraeroT2-T4 grill opening removal for cooling permitted without 16 square inch limit; mesh shape must match factory.
T4 BRZ vs BRZ TS #32022wordingwordingT3 Spec Lines: Subaru BRZ TS (13-21) now listed as 'Subaru BRZ, BRZ TS (13-21)'.
FA Reorganize Tables 1 and 2 #31985cars addedaddedFA adds Honda K20Z3 2.0L at 1350 lbs and Mazda MZR 2.0L at 1300 lbs; removes 4A-GE 1.8L and MZR 2.0L from Table 2; raises 1615cc baseline to 1250 lbs.
T4 Request Allowances for 2005 - 2010 Mustang #31624wording
AS Proposed Revisions to SCCA GCR 2021 Appendix M, Part 3 #30295wordingwordingSMG Long Tube Headers: Borla PN 17237 discontinued, approved alternatives American Racing MT3-05134300LSNC or Kooks PN 11312000.
AS specification line consolidation and correction #31846cars addedremovedcars addedAS Mercury Capri 79-86 removed as separate spec line, merged into Ford Mustang 79-93 spec line.
AS correction of SMG specification line #31847wordingremovedAS Spec Mustang SMG Restricted Prep removes 3.73 gear ratio and 355/300 brake disc sizes.
AS Alternate cylinder heads for full prep engine builds - Evaluation #31851engineaddedengineAS Camaro, Firebird, Mustang full prep engines: alternate GM and Ford Performance cylinder heads permitted regionally with Allstar restrictor ALL26180.
T4 Reply to letter 29879 T2-T4 Grill Openings #31486wordingwordingT2, T3, T4 clarify grill opening removal limited to 16 square inches for radiator cooling; mesh shape must be retained.
T4 Please Adjust 98-00 BMW 323 Min Weight to Reflect Current Class #31595weight -200 lbs
T4 Consolidate 12-13 and 14-15 Honda Civic Si spec lines for T4 #31596removed
T4 Request to clarify radiator hoses #31682otheraddedT2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted.
T4 Clarify Permitted/Allowed #31743wordingwordingT2, T3, T4: clarified that 'permitted' or 'allowed' parts in spec lines are alternatives to category rule allowances, not replacements.
T4 Adjust Honda FWD in T4 to encourage more Drivetrain Diversity #31472tyres & wheels
T4 Touring 4 BOP adjustments for 2022 #31482weight -175 lbs
T4 Request to Classify 2014 VW Jetta 1.8t TSI #30436cars addedaddedT4 adds 2014 VW Jetta 1.8T TSI to Spec Lines.
AS Request for adjustable Front Upper Control Arms on 4th Gen F-Body #30457otheraddedAS Chevrolet/Pontiac Camaro & Firebird 93-02 gains BMR AA004 or UMI 2310 adjustable front upper control arms.
AS Request Pontiac GTO tire size change #30881weightslowerweightAS Pontiac GTO 04-06 Restricted Prep minimum weight rises: LS1 to 3300 lbs, LS2 to 3350 lbs on 295 tires.
1:50.427Drew Cattell · fastest of 31 · top 5 within 1.9s+5.207s (+4.95%)
1:50.606Gregory Eaton · fastest of 28 · top 5 within 1.7s-0.901s (-0.81%)
153.8James Jost
1:54.397Stephen Blethen · fastest of 47 · top 5 within 0.9s-2.169s (-1.86%)
1:55.929John Heinricy · fastest of 46 · top 5 within 1.0s-0.994s (-0.85%)
127.3Alexander Schefer
+5.323squal +3.970s
104.8%qual 103.6%
1:57.695Brian Henderson · fastest of 90 · top 5 within 0.5s-0.611s (-0.52%)
1:58.837Brian Henderson · fastest of 88 · top 5 within 0.3s-0.263s (-0.22%)
119.8Kyle Greenhill
+8.231squal +7.268s
107.4%qual 106.6%
1:29.701James French · fastest of 18 · top 5 within 2.7s-0.256s (-0.28%)
1:30.650James French · fastest of 17 · top 5 within 6.1s-0.715s (-0.78%)
155.5James French
-19.956squal -20.726s
82.0%qual 81.2%
57 rule changes (AS: 14, T4: 20, SM: 1, FA: 22)14 cars added · 8 weight · 5 engine · 3 induction · 3 tyres & wheels · 1 suspension & brakes · 19 wording · 4 other · FA Mazda MZR 2.0 engine name shortened to Mazda MZR; Honda Civic K20Z3 name clarified. · Toyota 1800 moves from FA Table 1 to FA Table 2 Spec Line Cars. · FA Swift 016 Mazda MZR/Ford Duratec wheel width spec clarified: front 10, rear 14 min & 15 max inches. · FA rule text reorganized: purpose-built and ex-pro cars moved to Table 1, spec line cars to Table 2, with clarified engine note applicability. · FA Mazda MZR/Ford Duratec 2296cc and 2500cc moved from Table 1 to Table 2. · FA Mazda MZR 2.0L and Honda Civic K20Z3 change from 5-speed sequential to 5-speed. · AS Cadillac CTS-V 6.0L LS6 removes 295-tire 50 lb penalty. · AS consolidates seven SN95 Mustang '94-'04 spec lines into three unified lines by model year and engine. · AS Camaro/Firebird LT1 and LS1 transmission changed to TUET1 6362; Mustang GT 4.6L/5spd to TUKT16901, loses 300 lbs. · AS Camaro & Firebird and Mustang GT gear ratio specifications restored with alternate sets permitted. · AS Camaro, Firebird, Mustang, and Capri all gain 50 lbs minimum weight across seven model year variants. · FA Mazda MZR 2.0 limited to Ralt RT40, RT41, Swift 008, 014 chassis; Honda Civic K20Z3 removes Swift 016 chassis. · T3 Honda Civic Type-R 2020+ allowed brake rotor #45251-TGH-A01 with 25 lb penalty. · FA Swift 016 2.3 liter engine name corrected to Mazda MZR/Ford Duratec. · FA Swift 016 2.5 liter engine name corrected to Mazda MZR/Ford Duratec. · FA removes four spec lines (E–H); spec line D changes from Ford Duratec/Mazda MZR 2500 to Honda B16 1615, loses 29mm restrictor, weight 1400 to 1175 lbs. · FA Spec Lines C, I, K weights adjusted: C to 1175 lbs, I to 1175 lbs, K to 1175 lbs. · FA purpose-built and ex-Pro Atlantic cars remove sequential trans. 25 lb penalty redundant reference. · FA Ligier car name corrected to FR Americas Ligier JS F3. · FA Ford Duratec/Mazda MZR Spec Line D clarifies valve specification to 4 per cylinder, no performance change. · FA Honda Civic K20Z3 intake manifold and throttle body now may use AT Power Direct-To-Head 45mm individual throttle bodies PN 102-104-00020 as alternative. · SM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture. · T2-T4 clutch discs and pressure plates must be at least 95% of factory OEM weight, bolted to unmodified stock flywheel. · AS Mustang 4.6L 5spd gains cold air intake freedom; 5.0L 6spd now requires 56mm flat plate restrictor. · AS CTS-V 5.7L LS6 and 6.0L LS2 may use Driveshaft Shop P/N GMCTSV2-C carbon fiber driveshaft. · AS Chevrolet Camaro SS V8 6.2L Restricted Prep model years extended from 10–13 to 10–15. · FA Ford Duratec/Mazda MZR intake restrictor reduced from 32mm to 30mm SIR; Swift 016 2.5 Mazda restrictor reduced from 35mm to 33mm SIR. · FA Toyota 4A-GE Spec Lines A and B: engine designation and valve configuration clarified, weights and displacement unchanged. · FA Ford BD Series engine displacement increases from 1600 cc to 1615 cc; minimum weight stays 1200 lbs. · FA Ford Duratec/Mazda MZR and Honda B16 engines both now limited to 1615cc displacement; both lose NA restrictor requirement. · Pro Formula Mazda engine specifications moved from Table 1 to Table 2 spec line notes; no performance changes. · Toyota Supra 2020- added to T2 with 2998 cc engine, 3450 lbs minimum weight, 19×10 wheels, 295 tyres. · AS Ford Mustang GT 5.0L 15-17 Restricted added to Spec Line with 3600 lbs minimum weight, 55mm restrictor, 18×10 wheels, 295 tires. · AS underhood bracing on stock hoods, trunks, and rear decks may be modified or removed. · AS Cadillac CTS-V 04-07 with 295 tire drops to 3450 lbs; Camaro SS V8 10-13 and Challenger 08-20 specs removed. · AS Camaro & Firebird (93-02) and Mustang GT (05-14) specifications restored with weight minimums 3250–3500 and 3350–3600 lbs respectively. · Formula Lites Crawford FL15 added to FA classification effective 2021-01-01. · T2 BMW M2 CS Cup 2020+ classified at 2979 cc, 3625 lbs, 295 tires, 10.5×18 wheels, 380/390 mm brakes. · 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, plus 25 lb penalty. · T3 Scion FR-S/Toyota 86 and Subaru BRZ capped to 2021 model year; T4 models capped to 2021. · AS Dodge Challenger gains 6.1L and 6.4L V8 options; 5.7L weight rises to 3500 lbs on 295 tyres, 3600 on 315 tyres; compression to 10.9:1 max. · AS Camaro & Firebird (93-02) and Ford Mustang Coupe GT (05-14) spec lines consolidated; Camaro/Firebird now allows both LT1 and LS1 engines; Mustang now allows both 4.6L 3-valve and 5.0L 4-valve engines with restrictor. · T3 Alfa Romeo 4C Launch Edition variant now allowed.showhide
FA E&O Table 2 engine names #31085wordingwordingFA Mazda MZR 2.0 engine name shortened to Mazda MZR; Honda Civic K20Z3 name clarified.
FA Move Toyota 1800 to Table 2 #30822cars addedcars addedToyota 1800 moves from FA Table 1 to FA Table 2 Spec Line Cars.
FA E&O Swift 016 wheel width reference #30939wordingwordingFA Swift 016 Mazda MZR/Ford Duratec wheel width spec clarified: front 10, rear 14 min & 15 max inches.
FA Update FA rules package #30717wordingwordingFA rule text reorganized: purpose-built and ex-pro cars moved to Table 1, spec line cars to Table 2, with clarified engine note applicability.
FA Move Mazda MZR/Ford Duratec 2296cc and 2500cc to Table 2 #30718cars addedaddedFA Mazda MZR/Ford Duratec 2296cc and 2500cc moved from Table 1 to Table 2.
FA Clean up Table 2 Mazda MZR 2.0L and Honda Civic K20Z3 spec lines #30719wordingwordingFA Mazda MZR 2.0L and Honda Civic K20Z3 change from 5-speed sequential to 5-speed.
T4 Wrong Part Number on 320i Spec Line #30645wording
AS Request CTS-V Spec Line Error Correction #30242weightfasterweightAS Cadillac CTS-V 6.0L LS6 removes 295-tire 50 lb penalty.
AS Request to consolidate SN95 Mustang '94-'04 Mustang spec lines #30428wordingwordingAS consolidates seven SN95 Mustang '94-'04 spec lines into three unified lines by model year and engine.
AS American Sedan Transmission Rule Change Request #30595enginefasterengineAS Camaro/Firebird LT1 and LS1 transmission changed to TUET1 6362; Mustang GT 4.6L/5spd to TUKT16901, loses 300 lbs.
AS Correction to specifications inadvertently deleted #30691wordingwordingAS Camaro & Firebird and Mustang GT gear ratio specifications restored with alternate sets permitted.
AS weight adjustments #30700weight +50 lbsslowerweightAS Camaro, Firebird, Mustang, and Capri all gain 50 lbs minimum weight across seven model year variants.
FA E&O Mazda MZR 2.0 and Honda Civic K20Z3 chassis eligibility #30632cars addedremovedcars addedFA Mazda MZR 2.0 limited to Ralt RT40, RT41, Swift 008, 014 chassis; Honda Civic K20Z3 removes Swift 016 chassis.
T4 Civic Type R Brake Rotors #29817weightslowerweightT3 Honda Civic Type-R 2020+ allowed brake rotor #45251-TGH-A01 with 25 lb penalty.
FA Correct engine name in Swift 016 2.3 liter spec line #30447wordingwordingFA Swift 016 2.3 liter engine name corrected to Mazda MZR/Ford Duratec.
FA Correct engine name in Swift 016 2.5 liter spec line #30448wordingwordingFA Swift 016 2.5 liter engine name corrected to Mazda MZR/Ford Duratec.
FA Revise Table 1 Spec Lines and clarify application of Engine Notes #30456cars addedfastercars addedFA removes four spec lines (E–H); spec line D changes from Ford Duratec/Mazda MZR 2500 to Honda B16 1615, loses 29mm restrictor, weight 1400 to 1175 lbs.
FA Update Table 1 Weights for Spec Lines C, I, and K #30355weight -25 lbsfasterweightFA Spec Lines C, I, K weights adjusted: C to 1175 lbs, I to 1175 lbs, K to 1175 lbs.
FA Remove redundant reference in Table 2 spec line #30366wordingwordingFA purpose-built and ex-Pro Atlantic cars remove sequential trans. 25 lb penalty redundant reference.
FA Correct the name of the FR Americas car #30369wordingwordingFA Ligier car name corrected to FR Americas Ligier JS F3.
FA Clean up Spec Line D in Table 1 #30372wordingwordingFA Ford Duratec/Mazda MZR Spec Line D clarifies valve specification to 4 per cylinder, no performance change.
FA Table 2 Honda K20Z3 request #30386engineaddedengineFA Honda Civic K20Z3 intake manifold and throttle body now may use AT Power Direct-To-Head 45mm individual throttle bodies PN 102-104-00020 as alternative.
SM Updates - Obsolete Parts & BOP Parts #30438wordingaddedSM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture.
T4 Request consistency review in GCR #30263wordingwordingT2-T4 clutch discs and pressure plates must be at least 95% of factory OEM weight, bolted to unmodified stock flywheel.
AS AS Mustang LP 4.6 3V Classification Transmission Request #29886enginefasterengineAS Mustang 4.6L 5spd gains cold air intake freedom; 5.0L 6spd now requires 56mm flat plate restrictor.
AS Request CF driveshaft on CTS-V for durability improvement #30117otheraddedAS CTS-V 5.7L LS6 and 6.0L LS2 may use Driveshaft Shop P/N GMCTSV2-C carbon fiber driveshaft.
AS Adjustment to model years of 5th generation RP Camaro #30348cars addedaddedAS Chevrolet Camaro SS V8 6.2L Restricted Prep model years extended from 10–13 to 10–15.
FA E&O FA Intake Restrictors #30273inductionslowerinductionFA Ford Duratec/Mazda MZR intake restrictor reduced from 32mm to 30mm SIR; Swift 016 2.5 Mazda restrictor reduced from 35mm to 33mm SIR.
FA Clean up Spec Lines A and B in Table 1 #30274wordingwordingFA Toyota 4A-GE Spec Lines A and B: engine designation and valve configuration clarified, weights and displacement unchanged.
FA Clean up Spec Line C in Table 1 #30275enginefasterengineFA Ford BD Series engine displacement increases from 1600 cc to 1615 cc; minimum weight stays 1200 lbs.
FA Clean up Spec Lines J and L in Table 1 #30276engineengineFA Ford Duratec/Mazda MZR and Honda B16 engines both now limited to 1615cc displacement; both lose NA restrictor requirement.
FA Move engine specifications to Pro Formula Mazda spec line notes #30278wordingwordingPro Formula Mazda engine specifications moved from Table 1 to Table 2 spec line notes; no performance changes.
T4 Change part numbers on BRZ, FRS lines in T4 #30104wording
T4 T4 Mustang Axle Ratio and Wheels #30149tyres & wheels
AS Request for 2015 -2017 Ford Mustang Spec Line #29514cars addedaddedAS Ford Mustang GT 5.0L 15-17 Restricted added to Spec Line with 3600 lbs minimum weight, 55mm restrictor, 18×10 wheels, 295 tires.
AS Request Trunk lid / Rear Hatch clarification #29591wordingwordingAS underhood bracing on stock hoods, trunks, and rear decks may be modified or removed.
AS Common Weight for CTS-V Tire #29759weightfasterweightAS Cadillac CTS-V 04-07 with 295 tire drops to 3450 lbs; Camaro SS V8 10-13 and Challenger 08-20 specs removed.
AS Correction to specifications inadvertently deleted #30041cars addedaddedAS Camaro & Firebird (93-02) and Mustang GT (05-14) specifications restored with weight minimums 3250–3500 and 3350–3600 lbs respectively.
FA Request to classify Formula Lites Crawford FL15 #29702cars addedaddedFormula Lites Crawford FL15 added to FA classification effective 2021-01-01.
T4 Request to Classify BMW M2 CS #29523cars addedaddedT2 BMW M2 CS Cup 2020+ classified at 2979 cc, 3625 lbs, 295 tires, 10.5×18 wheels, 380/390 mm brakes.
T4 Allow the SpecMX-5 Update Kit Into Touring 4 for the MX-5 #29681otheraddedT3 and T4 Mazda MX-5 06-15 now allow Mazda Transmission kit part # 0000-02-5700.
T4 Request Mustang 8.8†rear axle replacement #29860cars addedaddedT4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.55 final drive, plus 25 lb penalty.
T4 Cap year range on all 86s #29908wordingwordingT3 Scion FR-S/Toyota 86 and Subaru BRZ capped to 2021 model year; T4 models capped to 2021.
AS Request Additional Engine Options for Dodge Challenger Spec Line #29543cars addedaddedAS Dodge Challenger gains 6.1L and 6.4L V8 options; 5.7L weight rises to 3500 lbs on 295 tyres, 3600 on 315 tyres; compression to 10.9:1 max.
AS Rule simplification spec line communization #29824cars addedcars addedAS Camaro & Firebird (93-02) and Ford Mustang Coupe GT (05-14) spec lines consolidated; Camaro/Firebird now allows both LT1 and LS1 engines; Mustang now allows both 4.6L 3-valve and 5.0L 4-valve engines with restrictor.
2:27.045Gregory Eaton · fastest of 18 · top 5 within 0.6s
2:27.668Gregory Eaton · fastest of 15 · top 5 within 1.5s
149.2Gregory Eaton
2:37.403John Heinricy · fastest of 20 · top 5 within 2.5s
2:37.881Chi Ho · fastest of 19 · top 5 within 1.6s
130.2Chi Ho
+10.213squal +10.358s
106.9%qual 107.0%
2:42.209Kyle Greenhill · fastest of 77 · top 5 within 0.5s
2:43.748Preston Pardus · fastest of 75 · top 5 within 1.0s
121.3Kyle Greenhill
+16.080squal +15.164s
110.9%qual 110.3%
2:04.274Spencer Brockman · fastest of 11 · top 5 within 2.7s
2:04.746Spencer Brockman · fastest of 10 · top 5 within 2.4s
150.6Hans Peter
-22.922squal -22.771s
84.5%qual 84.5%
58 rule changes (AS: 16, T4: 25, SM: 2, FA: 15)10 cars added · 7 engine · 6 suspension & brakes · 5 weight · 3 tyres & wheels · 2 aero · 1 induction · 19 wording · 5 other · SM allows aftermarket radiators in original location with stock OEM cooling fan, and permits 1990-1997 cars to install upper radiator seal NA75-50-OK7A. · AS Dodge Challenger 5.7L V8 now requires iron block instead of aluminum, compression to 10.5:1 max, intake valve 12.7 mm, exhaust 12.3 mm, intake timing 188 degrees, exhaust timing 205 degrees. · AS Dodge Challenger 08-14 rear spoiler: 1GL20RXF replaced with 1GL20TZZAB; 82211606 still permitted. · SM rear brake caliper may use single bracket under upper retaining bolt head to prevent pin failure. · AS class pursuing specified list of eligible tires; list details unclear from text provided. · AS class tire eligibility list under development; no specifications changed yet. · AS Coyote Mustang restrictor plate under review for 2021; no change effective yet. · AS Restricted Prep 4.6 3V now permits conversion to 2 valve configuration. · AS Ford Mustang Coupe GT 4.6L 3V Restricted Prep now permits Ford Performance camshaft kit P/N M-6550-3V. · 2010-2014 Camaro remains classified in AS; no specification changes. · AS class cylinder head supplier discontinuation; replacement option pending for 2021 season. · AS Mustang, Capri, Camaro, and Firebird maximum brake rotor diameter increased from 12.2 to 13.1 inches. · unclear · FA stock engine weight adjustment request denied; modified engines now permitted in FA. · Request to add vehicle to T2, T3, T4 roster; refer to letter #27663 in June 2020 Fastrack for decision. · FA engine modifications clarified: bore/stroke/flywheel unrestricted within displacement limits, distributor/ignition installation restricted, compression ratio machining allowed, table references updated. · FA transmissions limited to five forward speeds and operational reverse unless Table 2 notes otherwise. · FA Swift 016 Mazda Duratec: clarify Gurney flap wording, dimensions and allowed locations unchanged. · 2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine, 17-inch wheels, 245 tyres, EIBACH PN# 2563.140 springs allowed. · FA removes Volkswagen 1835cc SOHC engine specification line from Table 1. · FA engine rules clarify that blocks and heads must be OEM unless the tables note otherwise; wording only. · T3 BMW Z3 M & Coupe 98-99 minimum weight reduced to 3150 lbs. · FA Formula 1000 motorcycle-based engines gain maximum compression ratio of 14.5:1, up from 13.5:1. · FA removes Ex-FSV wheel width rules, all cars now front ten inches, rear fourteen to fifteen inches. · FA Formula 3 permitted engine years extended from 1997–2008 to 1997–2017. · FA Table 1 engine notes now apply only to Table 1, not Table E; FA Table 2 Pro Formula Mazda engine references Table 1 specs. · AS rear trailing arms may be replaced with tubular arms maintaining stock length and axle location purpose only. · AS Ford and GM full prep cars get increased weight reduction from 150 to 200 lbs. · 05-10 Ford Mustang Coupe GT 4.6L OHC classified AS with 3200 lbs minimum weight, HR cam permitted. · 10-15 Camaro Full Prep classified AS with 3400 lbs base weight, 3700 lbs over 313 CID, specific head castings and Edelbrock heads permitted. · Pontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18x9.5, Sky weight drops to 3200 lbs. · Mazda RX-8 Base/R3/Sport/GT (04-12) classified in T3 effective 2020-02-01. · Formula 1000 motorcycle-based engine up to 1000cc added to FA with unrestricted throttle bodies and ECUs. · unclear · FA Swift 016 2.3L Mazda Duratec restrictor reduced from 33mm to 31mm SIR. · T2 must have fire system installed; T3 and T4 may have one per GCR 9.3. · T3 Ford Mustang EcoBoost gains three transmission gear ratio options. · T3 and T4 Mazda RX-8 Base/R3 (04-12) reclassified to include Sport and GT variants. · Toyota 86 GT variant (2017–) added to T3 and T4 spec lines. · FA wheel diameter and width specifications moved from Bodywork subsection to General section. · FA Mazda MZR 2.0 engine use restricted to Ralt RT40, Ralt RT41, and Swift 014 chassis only.showhide
SM Radiator E&O Clarifications #29294wordingwordingSM allows aftermarket radiators in original location with stock OEM cooling fan, and permits 1990-1997 cars to install upper radiator seal NA75-50-OK7A.
AS Dodge Challenger AS Spec Line Clarification #28698engineslowerengineAS Dodge Challenger 5.7L V8 now requires iron block instead of aluminum, compression to 10.5:1 max, intake valve 12.7 mm, exhaust 12.3 mm, intake timing 188 degrees, exhaust timing 205 degrees.
AS Dodge Challenger AS Spec Line Clarification #2 #28699aeroaeroAS Dodge Challenger 08-14 rear spoiler: 1GL20RXF replaced with 1GL20TZZAB; 82211606 still permitted.
SM Modifications to prevent failures of Rear Brake Caliper Pin #28953suspension & brakessuspension & brakesSM rear brake caliper may use single bracket under upper retaining bolt head to prevent pin failure.
T4 Scion FRS Solo Spec Coupe Gear Ratio #29021other
AS Support for R-Type Specification Tires #27450wordingunclearAS class pursuing specified list of eligible tires; list details unclear from text provided.
AS Spec Tire Request #27519wordingunclearAS class tire eligibility list under development; no specifications changed yet.
AS Restrictor Plate Change for RP 2011+ Mustang with Coyote Engine #27675wordingunclearAS Coyote Mustang restrictor plate under review for 2021; no change effective yet.
AS 2005-2009 Restricted Prep 4.6 3V #27908engineaddedengineAS Restricted Prep 4.6 3V now permits conversion to 2 valve configuration.
AS Request for 2005-2009 Restricted Prep 4.6 3V Parts #27909engineaddedengineAS Ford Mustang Coupe GT 4.6L 3V Restricted Prep now permits Ford Performance camshaft kit P/N M-6550-3V.
AS Request for Full Preparation Classification for 2010-2014 Camaro #28030wordingunclear2010-2014 Camaro remains classified in AS; no specification changes.
AS Cylinder Heads #28696wordingunclearAS class cylinder head supplier discontinuation; replacement option pending for 2021 season.
AS Request for Max Rotor Diameter Change #28748otherfasterAS Mustang, Capri, Camaro, and Firebird maximum brake rotor diameter increased from 12.2 to 13.1 inches.
AS Request increase rotor diameter #28797wordingunclearunclear
FA Request to Adjust FB Weight for Stock Engines #29005wordingunclearFA stock engine weight adjustment request denied; modified engines now permitted in FA.
T4 Request to Add a Vehicle to the Roster (contd.) #27698wordingunclearRequest to add vehicle to T2, T3, T4 roster; refer to letter #27663 in June 2020 Fastrack for decision.
FA E&O permitted engine modifications #28831wordingwordingFA engine modifications clarified: bore/stroke/flywheel unrestricted within displacement limits, distributor/ignition installation restricted, compression ratio machining allowed, table references updated.
FA E&O Transmissions #28832wordingwordingFA transmissions limited to five forward speeds and operational reverse unless Table 2 notes otherwise.
FA Swift 016 Gurney flap wicker clarification #28884wordingwordingFA Swift 016 Mazda Duratec: clarify Gurney flap wording, dimensions and allowed locations unchanged.
T4 Request to Classify 2004 Mercedes Benz 320 CLK #27663cars addedadded2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine, 17-inch wheels, 245 tyres, EIBACH PN# 2563.140 springs allowed.
AS weight adjustments for 2020 season #28785weight -50 lbs
FA Remove redundant spec line in Table 1 #28720engineremovedengineFA removes Volkswagen 1835cc SOHC engine specification line from Table 1.
FA E&O general engine rules #28772wordingwordingFA engine rules clarify that blocks and heads must be OEM unless the tables note otherwise; wording only.
T4 Request to change allowed header part # for T4 06-15 Miata #28223wording
T4 Z3M Roadster Weight #28437weightfasterweightT3 BMW Z3 M & Coupe 98-99 minimum weight reduced to 3150 lbs.
FA Request higher compression ratio and prior weights for F1000 cars #28162enginefasterengineFA Formula 1000 motorcycle-based engines gain maximum compression ratio of 14.5:1, up from 13.5:1.
FA Remove redundant wheel dimension provisions #28554tyres & wheelstyres & wheelsFA removes Ex-FSV wheel width rules, all cars now front ten inches, rear fourteen to fifteen inches.
FA E&O Formula 3 spec line #28596engineaddedengineFA Formula 3 permitted engine years extended from 1997–2008 to 1997–2017.
FA FA weight correction/clarification #28430wordingwordingFA Table 1 engine notes now apply only to Table 1, not Table E; FA Table 2 Pro Formula Mazda engine references Table 1 specs.
T4 Request for 12-13 and 14-15 Honda Civic Springs #27848suspension & brakes
T4 Request to Clarify T4 05-10 Mustang Spring Allowance #27899suspension & brakes
AS Rear Trailing Arms #28007suspension & brakesaddedsuspension & brakesAS rear trailing arms may be replaced with tubular arms maintaining stock length and axle location purpose only.
AS Weight reduction for cars running iron heads #28010weightfasterweightAS Ford and GM full prep cars get increased weight reduction from 150 to 200 lbs.
AS 05-10 Mustang with HR cam classification #28226cars addedadded05-10 Ford Mustang Coupe GT 4.6L OHC classified AS with 3200 lbs minimum weight, HR cam permitted.
AS 10-15 Camaro Full Prep classification #28227cars addedadded10-15 Camaro Full Prep classified AS with 3400 lbs base weight, 3700 lbs over 313 CID, specific head castings and Edelbrock heads permitted.
T4 Request to Allow Brake Upgrade on T4 Mustang #27329suspension & brakes
T4 Please Switch the Solstice GXP as Specified in T2, to T3 #27413cars added -50 lbsfastercars addedPontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18x9.5, Sky weight drops to 3200 lbs.
T4 Request to Classify all Mazda RX8 Models in T3/T4 #27606cars addedaddedMazda RX-8 Base/R3/Sport/GT (04-12) classified in T3 effective 2020-02-01.
FA Request to merge FB into FA #25611cars addedaddedFormula 1000 motorcycle-based engine up to 1000cc added to FA with unrestricted throttle bodies and ECUs.
FA Suggestions for FB/F1000 into FA #27319otherunclearunclear
FA Change Swift 016 - 2.3 liter Mazda Duratec restrictor size #27880inductionslowerinductionFA Swift 016 2.3L Mazda Duratec restrictor reduced from 33mm to 31mm SIR.
T4 Clarification of On-Board Fire System for T2 #27183wordingwordingT2 must have fire system installed; T3 and T4 may have one per GCR 9.3.
T4 Mustang Ecoboost and GT Transmission #27439cars addedaddedT3 Ford Mustang EcoBoost gains three transmission gear ratio options.
T4 BRZ/FRS/86 Tire Size in T4 #27660tyres & wheels
T4 T4 RX8 Classification Error #27902cars addedaddedT3 and T4 Mazda RX-8 Base/R3 (04-12) reclassified to include Sport and GT variants.
T4 Request to add Toyota 86 GT to Spec Line #27910cars addedaddedToyota 86 GT variant (2017–) added to T3 and T4 spec lines.
FA Move wheel dimensions from Bodywork subsection to #27493wordingwordingFA wheel diameter and width specifications moved from Bodywork subsection to General section.
FA Table 2 Mazda MZR 2.0 E&O #27640wordingwordingFA Mazda MZR 2.0 engine use restricted to Ralt RT40, Ralt RT41, and Swift 014 chassis only.
2:02.938Gregory Eaton · fastest of 17 · top 5 within 0.8s
2:03.900James Jost · fastest of 16 · top 5 within 2.1s
153.9James Jost
2:11.257John Heinricy · fastest of 25 · top 5 within 0.2s
2:10.959Nick Leverone · fastest of 25 · top 5 within 0.6s
128.9Tommy Boileau
+7.059squal +8.319s
105.7%qual 106.8%
2:14.552Todd Buras · fastest of 60 · top 5 within 0.2s
2:16.459Elivan Goulart · fastest of 56 · top 5 within 0.4s
119.8Jim Drago
+12.559squal +11.614s
110.1%qual 109.4%
1:41.545Dario Cangialosi · fastest of 8 · top 5 within 2.8s
1:43.107Dario Cangialosi · fastest of 8 · top 5 within 1.8s
155.9Kent Vaccaro
-20.793squal -21.393s
83.2%qual 82.6%
30 rule changes (AS: 4, T4: 15, SM: 4, FA: 7)5 cars added · 4 engine · 4 weight · 3 suspension & brakes · 1 induction · 1 removed · 9 wording · 3 other · AS Spec Mustang (SMG) added as Restricted Prep class. · FA Honda Civic K20Z3 engine for Swift 014 and 016 chassis consolidated to single spec line with 1350 lbs minimum weight. · FA Swift 014 Mazda MZR 2.0 piston minimum weight drops from 320g to 280g; maximum dome height limit removed. · T2, T3, T4 spare tire and cover removal wording clarified; removable covers now explicitly allowable to remove. · AS class ride height minimum clarified: five inches measured at rocker panel, excluding seams and stock effects. · AS Ford Mustang 79-93 non-Cobra drops 100 lbs to 3150; over 313 CID Cobra drops 100 lbs to 3450. · FA Line N minimum weight raised to 1375 lbs. · FA cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs. · FA Formula 3 car transmission rules clarified: up to 6 forward gears, limited-slip differential, sequential removed, 25 lb penalty deleted. · SM fuel pump and filter now permitted as Mazda or OEM equivalent part. · T4 and T3 Mazda MX-5 hardtop rules clarified: any OEM or aftermarket top permitted if retaining OEM silhouette; specific part numbers listed. · T2, T3, T4 now allow any thermostat serving original equipment intent only. · T3 and T4 Mazda MX-5 Miata eligibility capped at 2016–2018 model years. · AS adds Spec Mustang SMG classification with 107.1 wheelbase, 3.73 gears, 355mm front and 300mm rear brakes. · FA Swift 014-Mazda MZR 2.0 engine no longer sealed by Elite Engines; block, crank, rods, head, cams, manifold now specified with part numbers and dimensions. · FA Swift 016 Mazda 2.3 and 2.5 liter minimum weight increases 30 lbs to 1450. · SM allows factory Mazda ECU and injector harnesses (P/N 0000-10-020E-99, 0000-10-080D-99) on 1999–2000 model year cars, unmodified. · SM electrical rules reorganized and clarified; alternator now externally regulated only by OEM ECU or master kill switch; harness repair by splicing permitted. · SM tire tread protrusion language removed from GCR 9.1.7.C.5. · T4 Celica GT wheelbase 2600 and 15x7 wheels added; Forte years narrowed; Fiesta ST starts 2014; Fiat 124 years 16-18 added; battery rule clarified. · T1–T4 spec car classifications clarified with permitted parts, rule conformance versions, and exclusions of other touring modifications. · T2–T4 subframe bushings now permitted to be replaced with non-spherical bushings of any material.showhide
AS Request to add SMG to 9.1.6.B.1 AS Intent #27140cars addedaddedAS Spec Mustang (SMG) added as Restricted Prep class.
FA Follow up to Letter #27344 on Honda Powered FA Rules #27363removedremovedFA Honda Civic K20Z3 engine for Swift 014 and 016 chassis consolidated to single spec line with 1350 lbs minimum weight.
FA Swift 014 Mazda MZR 2.0 E&O #27305enginefasterengineFA Swift 014 Mazda MZR 2.0 piston minimum weight drops from 320g to 280g; maximum dome height limit removed.
T4 Request spare tire/wheel clarification #27012wordingfasterT2, T3, T4 spare tire and cover removal wording clarified; removable covers now explicitly allowable to remove.
AS Request Ride Height Clarification #26598wordingwordingAS class ride height minimum clarified: five inches measured at rocker panel, excluding seams and stock effects.
AS Request to Revert to 2017 Weights #25885weightfasterweightAS Ford Mustang 79-93 non-Cobra drops 100 lbs to 3150; over 313 CID Cobra drops 100 lbs to 3450.
FA Adjust Line N restrictor size and minimum weight #26691weight +30 lbsslowerweightFA Line N minimum weight raised to 1375 lbs.
T4 Request to allow piggy back ECU on 2000 Mazda Protégé #26085engine
T4 Request helper spring as optional #26678suspension & brakes
FA Add data plate requirement #26707otheraddedFA cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs.
T4 Request to classify 2000 - 2001 BMW 323 #25096cars added
FA Request to add FA engine spec lines #26183wordingwordingFA Formula 3 car transmission rules clarified: up to 6 forward gears, limited-slip differential, sequential removed, 25 lb penalty deleted.
SM Request to allow aftermarket fuel filters. #26370otheraddedSM fuel pump and filter now permitted as Mazda or OEM equivalent part.
T4 Correct Mazda MX-5 Hard Top Notes #26137wordingwordingT4 and T3 Mazda MX-5 hardtop rules clarified: any OEM or aftermarket top permitted if retaining OEM silhouette; specific part numbers listed.
T4 Consider opening class rules to allow any thermostat #26187engineaddedengineT2, T3, T4 now allow any thermostat serving original equipment intent only.
T4 Cap 2016 Mazda Miata year at 2018 #26388cars addedremovedcars addedT3 and T4 Mazda MX-5 Miata eligibility capped at 2016–2018 model years.
AS SMG Mustang eligibility in American sedan #26224cars addedaddedAS adds Spec Mustang SMG classification with 107.1 wheelbase, 3.73 gears, 355mm front and 300mm rear brakes.
FA FA MZR 2.0 Engine Specification #25814engineengineFA Swift 014-Mazda MZR 2.0 engine no longer sealed by Elite Engines; block, crank, rods, head, cams, manifold now specified with part numbers and dimensions.
FA FA 016 weight increase #26063weightslowerweightFA Swift 016 Mazda 2.3 and 2.5 liter minimum weight increases 30 lbs to 1450.
SM Request 99-00 replacement Wire harnesses #25602otheraddedSM allows factory Mazda ECU and injector harnesses (P/N 0000-10-020E-99, 0000-10-080D-99) on 1999–2000 model year cars, unmodified.
SM Organize and Clarify 9.1.7.C.1.o. #25913wordingwordingSM electrical rules reorganized and clarified; alternator now externally regulated only by OEM ECU or master kill switch; harness repair by splicing permitted.
SM Strike Tire Tread Language #26123wordingremovedSM tire tread protrusion language removed from GCR 9.1.7.C.5.
T4 2012-2015 Honda Civic Si Performance Request #26129suspension & brakes
T4 Errors, Omissions, and Updates (Various) #22414wordingwordingT4 Celica GT wheelbase 2600 and 15x7 wheels added; Forte years narrowed; Fiesta ST starts 2014; Fiat 124 years 16-18 added; battery rule clarified.
T4 Request for Adjustments to fiat 124 specline #25371induction
T4 Add Clarification to Spec Car Classifications Vehicle Spec #25774wordingwordingT1–T4 spec car classifications clarified with permitted parts, rule conformance versions, and exclusions of other touring modifications.
T4 Clarify Subframe Bushings Permitted for T2-T4 #25800suspension & brakesaddedsuspension & brakesT2–T4 subframe bushings now permitted to be replaced with non-spherical bushings of any material.
T4 Consider Solo SSC cross over classification into T4 #25802cars added
Every event the class ran, at any track, oldest to newest on the chart and newest first in the table. Each point is the class's best lap as a share of AS's best on the same day: the weather and the day cancel out, so one figure compares across years where lap times cannot; a class that suits one track more than another still reads differently there. It still moves when the yardstick's own balance changes or its field thins, and an event the yardstick did not run has no point. A best from fewer than three cars is greyed. The rule changes that took effect between two events are folded between their rows.