BoP Lab / Classes / FF

FF vs AS vs SM vs FA pace at every track

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

Class · click a class to switch, + to compare alongside (up to 4: remove one to add another)

vsAS ×B-SpecEPvsFA ×FCFE2FF×FPFVFXGT1GT2GTXHPPP2vsSM ×SMXSRF3STLSTUT1T2T3T4Show 51 inactive classes

Series Runoffs Super Tour Both

Reference · what % is measured against

Tracks · untick to narrow Auto Club Speedway Barber Motorsports Park Blackhawk Farms Raceway Buttonwillow Raceway Park Circuit of St. Louis (formerly Gateway Motorsports Circuit of the Americas Daytona International Speedway Grattan Raceway Hallett Motor Racing Circuit Homestead-Miami Speedway Indianapolis Motor Speedway Laguna Seca Michelin Raceway Road Atlanta Mid-Ohio Sports Car Course New Jersey Motorsports Park NOLA Motorsports Park Pacific Raceways Pittsburgh International Race Complex Portland International Raceway Pueblo Motorsports Park Road America Sebring International Raceway Sonoma Raceway Summit Point Raceway Thunderhill Raceway Park Virginia International Raceway Watkins Glen International Willow Springs Raceway World Wide Technology Raceway

Closest to the field: FF 100.0% of FF Rick Payne, Daytona International Speedway Runoffs 2015 race · AS 88.2% of FF James Jost, Virginia International Raceway Runoffs 2019 race · SM 97.1% of FF Elivan Goulart, Virginia International Raceway Runoffs 2019 race · FA 73.4% of FF Dario Cangialosi, Virginia International Raceway Runoffs 2019 race

% of FFLap times

FFASSMFAsolid race · dashed qualifying · slower is lower

FFASSMFAsolid race · dashed qualifying · each class's best lap as a share of FF's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker

	Event	FF			AS					SM					FA
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs FF	% of FF	Qual best	Race best	Trap	vs FF	% of FF	Qual best	Race best	Trap	vs FF	% of FF
	Road America Runoffs 20262026-09-28	2:23.047David Ybarra · fastest of 20 · top 5 within 1.4s-1.858s (-1.28%)	2:23.686Nathan Down · fastest of 20 · top 5 within 1.6s-1.855s (-1.27%)	138.9Tazio Stefanelli+0.5 mph (+0.3%)	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%)	+4.785squal +3.864s	103.3%qual 102.7%	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%)	+19.039squal +19.126s	113.3%qual 113.4%	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%)	-20.352squal -20.534s	85.8%qual 85.6%
24 rule changes (FF: 2, AS: 13, SM: 2, FA: 7)4 cars added · 4 engine · 2 induction · 2 tyres & wheels · 2 weight · 1 aero · 1 suspension & brakes · 5 wording · 3 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. · FF Kent 1600 compression ratio calculation parameters reorganized: bore size and valve protrusion limits moved to separate subsections for clarity. · 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. · 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. · FF clarifies alternative tire eligibility: homologated 1989 or earlier with rocker or outboard suspension all four corners; push-rod/pull-rod cars may seek approval. · 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.showhide 2026-09-01 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. 2026-09-01 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. 2026-08-01 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. 2026-08-01 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. 2026-08-01 AS Errors and Omissions #40532weightslowerweightAS Ford Mustang Coupe GT 05-14 Gen3 Coyote minimum weight increases from 3100 to 3400 lbs. 2026-08-01 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. 2026-07-01 FF Clarification in FF Kent 1600 Compression Ratio Paragraph #40293wordingwordingFF Kent 1600 compression ratio calculation parameters reorganized: bore size and valve protrusion limits moved to separate subsections for clarity. 2026-07-01 SM Rear Toe Link #40271wordingwordingSM/SMX Mazda rear toe link part number revised from 0000-04-5361426 to 0000-04-5361. 2026-06-01 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. 2026-06-01 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. 2026-04-01 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. 2026-04-01 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. 2026-04-01 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. 2026-03-01 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. 2026-02-01 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. 2026-02-01 FA Pro Mazda Classification and Performance Enhancement Proposal #39411enginefasterenginePro Formula Mazda allows lower intake manifold unrestricted, throttle body increased to 80mm maximum. 2026-01-01 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. 2026-01-01 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. 2026-01-01 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. 2026-01-01 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. 2026-01-01 FF Formula F Alternative Tire Rule Proposed Clarifications #39281tyres & wheelsaddedtyres & wheelsFF clarifies alternative tire eligibility: homologated 1989 or earlier with rocker or outboard suspension all four corners; push-rod/pull-rod cars may seek approval. 2025-12-01 AS 1994 Mustang Spec Line Request #39104engineaddedengineAS Ford Mustang GT 94-04 Restricted Prep Engine now permits Ford Motorsport M-6250-F303 camshaft. 2025-11-01 AS Cadillac CTS-V BOP Weight Change #38640weight -50 lbsfasterweightAS Cadillac CTS-V 04-07 Restricted Prep minimum weight drops to 3400 lbs. 2025-11-01 FA Re-Consider USF Pro 2000 Car for Formula Atlantic Class #38783cars addedaddedFA class adds USF Pro 2000 car as permitted model.
	Road America Runoffs 20252025-09-29	2:24.905Jonathan Kotyk · fastest of 17 · top 5 within 1.1s+2.353s (+1.65%)	2:25.541Calvin Kautz · fastest of 16 · top 5 within 0.5s+3.484s (+2.45%)	138.4Tazio Stefanelli-2.3 mph (-1.6%)	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%)	+3.691squal +1.887s	102.5%qual 101.3%	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%)	+18.889squal +18.206s	113.0%qual 112.6%	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%)	-22.887squal -23.982s	84.3%qual 83.4%
22 rule changes (FF: 4, AS: 11, SM: 4, FA: 3)4 engine · 3 tyres & wheels · 2 cars added · 2 weight · 1 induction · 7 wording · 3 other · 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. · FF adds rocker arm and outboard suspension cars option to use Hoosier bias ply slicks or VFF tyres; clarifies mixing rules. · 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. · FF adds alternative tire options for older cars with rocker arm or outboard suspension: bias ply slicks or VFF radials. · FA adds Formula Regional European Championship Tatuus F.3 T-318 or FR-19 as spec line car in Table 2. · 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. · 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. · FF and FC sequential gearbox weight penalty reduces from 25 lbs to 10 lbs minimum weight addition. · FF Honda Fit pistons: OEM 0.25mm oversize PN 13020-RB7-Z00 or Fast Forward PN FF800-110 now both allowed; standard diameter 73.240mm (2.8835 inches), minimum weight 198.0g.showhide 2025-07-01 AS RE: Previous Letter 37695 Update #38245weight -75 lbsfasterweightAS Ford Mustang GT 5.0 2018- minimum weight reduced to 3525 lbs. 2025-07-01 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. 2025-06-01 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. 2025-06-01 SM SMX Data Submission - Penalties #38248otheraddedSMX drivers must submit data acquisition files on time or face suspension and $250 fine. 2025-06-01 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. 2025-05-01 AS Errors and Omission #38055inductionslowerinductionAS Ford Mustang GT 5.0L 15-17 flat plate restrictor reduces from 67mm to 64mm. 2025-05-01 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. 2025-05-01 FF Page 228, FF tire rule 9.1.1.10.e #38251tyres & wheelsaddedtyres & wheelsFF adds rocker arm and outboard suspension cars option to use Hoosier bias ply slicks or VFF tyres; clarifies mixing rules. 2025-05-01 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. 2025-04-01 AS Flotek Head Plunge Cut Inconsistencies #37502wordingwordingAS Flotek head value seat cutting dimensions figure updated for consistency. 2025-04-01 AS Notes clean up #37693wordingwordingAS class notes cleaned: fuel cell and ECM specifications removed from multiple Camaro, Firebird, Challenger and Mustang variants. 2025-03-01 AS Race memo #37902wordingwordingAS removes 'Any ECM maybe used' note from five Cadillac and Chevrolet/Pontiac V8 Restricted Prep models. 2025-03-01 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. 2025-03-01 FF Formula F Proposal to Invite Older Cars Via a Tire Rule Change #37802tyres & wheelsaddedtyres & wheelsFF adds alternative tire options for older cars with rocker arm or outboard suspension: bias ply slicks or VFF radials. 2025-02-01 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. 2025-01-01 AS Increase Coyote Engine Restrictor to 80mm #36177enginefasterengineAS Ford Mustang and Cobra Coyote engine restrictor increases to 80mm from 67mm or 64mm. 2025-01-01 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. 2025-01-01 AS Gear Ratios #37131otheraddedAS class: multiple American muscle cars gain additional allowed gear ratio options across model years and prep levels. 2025-01-01 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. 2024-12-01 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. 2024-11-01 FF Change FF/FC Weight with Sequential Gearbox #36651weightfasterweightFF and FC sequential gearbox weight penalty reduces from 25 lbs to 10 lbs minimum weight addition. 2024-11-01 FF Alternative Oversize Honda Fit Pistons #37064engineaddedengineFF Honda Fit pistons: OEM 0.25mm oversize PN 13020-RB7-Z00 or Fast Forward PN FF800-110 now both allowed; standard diameter 73.240mm (2.8835 inches), minimum weight 198.0g.
	Road America Runoffs 20242024-10-01	2:22.552Calvin Kautz · fastest of 13 · top 5 within 1.1s-0.364s (-0.25%)	2:22.057Sebastian Mateo Naranjo · fastest of 13 · top 5 within 0.6s-2.211s (-1.53%)	140.7Calvin Kautz+2.6 mph (+1.9%)	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%)	+4.372squal +4.026s	103.1%qual 102.8%	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%)	+19.429squal +18.554s	113.7%qual 113.0%	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%)	-20.267squal -20.992s	85.7%qual 85.3%
17 rule changes (FF: 2, AS: 11, SM: 4)5 cars added · 3 engine · 1 tyres & wheels · 3 wording · 5 other · FF EGR blanking plate rule clarified: VTEC activation valve must be retained and functioning, no modifications permitted. · 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. · 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. · 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… · FF Honda Fit gains Fast Forward oversize piston ring option PN FF800-100 as alternative to Riken or Nippon.showhide 2024-10-01 FF Update to FF EGR Blanking Plate Rule #36633wordingwordingFF EGR blanking plate rule clarified: VTEC activation valve must be retained and functioning, no modifications permitted. 2024-09-01 AS Mustang transmission ratios #36662otheraddedAS Mustang GT 05-14 Restricted Prep and 2018- gain alternate transmission ratio options. 2024-09-01 SM SMX Camera Rule Correction #36496wordingwordingSMX Spec MX-5 camera requirement: non-functioning recorder now will instead of may warrant penalty or disqualification. 2024-09-01 SM Committee) AIM ECU Protocol #36556engineaddedengineSM and SMX must run latest AIM Data Logger Spec MX-5 ECU Protocol, effective 2024-09-01. 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. 2024-09-01 SM Committee) Shifter Bushing #36611otheraddedSM and SMX now allow an alternate shifter bushing at the bottom of the shift lever. 2024-06-01 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. 2024-05-01 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. 2024-05-01 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. 2024-05-01 AS Full Prep Head #35891engineaddedengineAS Chevrolet Camaro, Firebird, and Ford Mustang now permit Flo Tek cylinder heads in multiple generations. 2024-04-01 AS Restricted Prep Aftermarket Parts Request #35682otheraddedAS Camaro, Firebird 93-02 and GTO 04-06 add approved LS1 connecting rod part numbers to Notes. 2024-04-01 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. 2024-03-01 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. 2024-03-01 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. 2024-03-01 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. 2024-03-01 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… 2024-01-01 FF Honda Fit Oversize Piston Rings #35305engineaddedengineFF Honda Fit gains Fast Forward oversize piston ring option PN FF800-100 as alternative to Riken or Nippon.
	Virginia International Raceway Runoffs 20232023-09-23	1:59.249Nolan Allaer · fastest of 8 · top 5 within 2.8s+0.034s (+0.03%)	2:00.583Jonathan Kotyk · fastest of 8 · top 5 within 0.4s-17.775s (-12.85%)	138.4Calvin Kautz+0.1 mph (+0.1%)	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%)	+3.537squal +3.833s	102.9%qual 103.2%	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%)	+15.646squal +15.737s	113.0%qual 113.2%
13 rule changes (FF: 1, AS: 4, SM: 1, FA: 7)2 tyres & wheels · 2 weight · 1 cars added · 1 engine · 1 induction · 4 wording · 2 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. · 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. · FF Honda Fit engine adds Fast Forward part number alternatives for intake, exhaust, oil system, and scavenge pump components. · 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. · 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.showhide 2023-08-01 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. 2023-08-01 AS Request wheel size change #33007tyres & wheelsfastertyres & wheelsAS Ford Mustang GT 5.0L (15-17) Restricted maximum wheel diameter increases to 19.0 inches. 2023-08-01 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. 2023-08-01 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. 2023-06-01 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. 2023-05-01 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. 2023-05-01 FA Add new spec line for MSR Formula Mazda FMzR to Table 2 #34139cars addedaddedFA MSR Formula Mazda FMzR added to Table 2 classification. 2023-03-01 FF Add Fast Forward Part Numbers for Honda Fit Engine #33752engineaddedengineFF Honda Fit engine adds Fast Forward part number alternatives for intake, exhaust, oil system, and scavenge pump components. 2023-01-01 FA BDA Displacement #33431otherunclearUnable to complete: rule text does not show the spec line to be added to FA Table 1 for BDA displacement. 2023-01-01 SM BOP for NB1 and NB2 #32309weightslowerweightSM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore. 2022-12-01 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. 2022-12-01 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. 2022-10-01 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.
	Virginia International Raceway Runoffs 20222022-09-24	1:59.215Jonathan Kotyk · fastest of 13 · top 5 within 1.2s-0.348s (-0.29%)	2:18.358Jonathan Kotyk · fastest of 12 · top 5 within 2.4s-2.116s (-1.51%)	138.3Tim Kautz+2.2 mph (+1.6%)	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%)	-13.780squal +2.947s	90.0%qual 102.5%	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%)	+0.749squal +15.449s	100.5%qual 113.0%	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%)	-29.851squal -14.512s	78.4%qual 87.8%
17 rule changes (AS: 9, SM: 1, FA: 7)3 cars added · 2 engine · 2 weight · 1 tyres & wheels · 8 wording · 1 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. · 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. · FA Pro Formula Mazda now allows street port or bridge port; porting was previously not permitted. · 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. · 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 2022-09-01 AS Request to add Hoosier W2 #33031tyres & wheelsaddedtyres & wheelsAS adds Hoosier W2 wet tyre option alongside R7, R6, WET/H20. 2022-09-01 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. 2022-07-01 AS Request CTS-V Spec Line Error Correction #30242weightfasterweightAS Cadillac CTS-V 6.0L V8 Restricted Prep removes 295 tire size 50 lb penalty. 2022-05-01 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. 2022-05-01 FA Clarify verification of sealed engine compliance #32522wordingwordingFA sealed engines now require full inspection by stewards; competitor pays all reassembly and resealing costs. 2022-05-01 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. 2022-04-01 FA E&O FA Transmission section #32251wordingwordingFA: transverse gearbox shafts prohibited except final drive and motorcycle gearbox in Formula 1000. 2022-04-01 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. 2022-04-01 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. 2022-03-01 FA Closing the Gap #31934enginefasterengineFA Pro Formula Mazda now allows street port or bridge port; porting was previously not permitted. 2022-02-01 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. 2022-01-01 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. 2022-01-01 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. 2022-01-01 AS correction of SMG specification line #31847wordingremovedAS Spec Mustang SMG Restricted Prep removes 3.73 gear ratio and 355/300 brake disc sizes. 2022-01-01 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. 2021-10-01 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. 2021-10-01 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.
	Indianapolis Motor Speedway Runoffs 20212021-09-25	1:44.359Jonathan Kotyk · fastest of 24 · top 5 within 1.1s-0.242s (-0.23%)	1:55.676Jonathan Kotyk · fastest of 23 · top 5 within 1.8s+11.152s (+10.67%)	141.6Nicholas Sheppard	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	-5.070squal +6.068s	95.6%qual 105.8%	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	+3.161squal +13.336s	102.7%qual 112.8%	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	-25.026squal -14.658s	78.4%qual 86.0%
40 rule changes (FF: 3, AS: 14, SM: 1, FA: 22)10 cars added · 5 engine · 4 weight · 1 induction · 17 wording · 3 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. · 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. · FF block relief permitted only as needed to fit an allowed crankshaft. · SM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture. · 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. · 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. · 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. · FF class cylinder head now permits optional coolant bleed line pipe thread fitting to swirl tower. · FF Honda LC1 ECU supplied by HPD is permitted effective 12/1/2020 with HPD lambda sensor.showhide 2021-09-01 FA E&O Table 2 engine names #31085wordingwordingFA Mazda MZR 2.0 engine name shortened to Mazda MZR; Honda Civic K20Z3 name clarified. 2021-08-01 FA Move Toyota 1800 to Table 2 #30822cars addedcars addedToyota 1800 moves from FA Table 1 to FA Table 2 Spec Line Cars. 2021-08-01 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. 2021-07-01 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. 2021-07-01 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. 2021-07-01 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. 2021-06-01 AS Request CTS-V Spec Line Error Correction #30242weightfasterweightAS Cadillac CTS-V 6.0L LS6 removes 295-tire 50 lb penalty. 2021-06-01 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. 2021-06-01 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. 2021-06-01 AS Correction to specifications inadvertently deleted #30691wordingwordingAS Camaro & Firebird and Mustang GT gear ratio specifications restored with alternate sets permitted. 2021-06-01 AS weight adjustments #30700weight +50 lbsslowerweightAS Camaro, Firebird, Mustang, and Capri all gain 50 lbs minimum weight across seven model year variants. 2021-06-01 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. 2021-05-01 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. 2021-05-01 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. 2021-05-01 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. 2021-04-01 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. 2021-04-01 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. 2021-04-01 FA Correct the name of the FR Americas car #30369wordingwordingFA Ligier car name corrected to FR Americas Ligier JS F3. 2021-04-01 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. 2021-04-01 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. 2021-04-01 FF Kent crankshaft clarification #30426wordingwordingFF block relief permitted only as needed to fit an allowed crankshaft. 2021-04-01 SM Updates - Obsolete Parts & BOP Parts #30438wordingaddedSM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture. 2021-03-01 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. 2021-03-01 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. 2021-03-01 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. 2021-03-01 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. 2021-03-01 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. 2021-03-01 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. 2021-03-01 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. 2021-03-01 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. 2021-03-01 FA Update F3 Americas spec line #30280other 2021-01-01 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. 2021-01-01 AS Request Trunk lid / Rear Hatch clarification #29591wordingwordingAS underhood bracing on stock hoods, trunks, and rear decks may be modified or removed. 2021-01-01 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. 2021-01-01 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. 2021-01-01 FA Request to classify Formula Lites Crawford FL15 #29702cars addedaddedFormula Lites Crawford FL15 added to FA classification effective 2021-01-01. 2020-12-01 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. 2020-12-01 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. 2020-12-01 FF Allow Optional Coolant Bleed Line to Correct a Known Problem #29673otheraddedFF class cylinder head now permits optional coolant bleed line pipe thread fitting to swirl tower. 2020-12-01 FF Clarification regarding Honda LC1 ECU implementation date #29684wordingwordingFF Honda LC1 ECU supplied by HPD is permitted effective 12/1/2020 with HPD lambda sensor.
	Road America Runoffs 20202020-10-02	2:22.916Simon Sikes · fastest of 14 · top 5 within 1.6s	2:24.268Jeffrey Bartz · fastest of 14 · top 5 within 0.4s	138.1Jeffrey Bartz	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	+3.400squal +4.129s	102.4%qual 102.9%	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	+19.480squal +19.293s	113.5%qual 113.5%	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	-19.522squal -18.642s	86.5%qual 87.0%
37 rule changes (FF: 4, AS: 16, SM: 2, FA: 15)8 engine · 3 cars added · 2 suspension & brakes · 2 tyres & wheels · 2 weight · 1 aero · 1 induction · 16 wording · 2 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. · FF Honda LC1 ECU implementation date clarified to pending, contingent on SCCA receiving sufficient support materials. · 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. · 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. · 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. · 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. · FF Kent Engine alternator becomes optional instead of not required. · 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. · FF permits HPD LC1 ECU with lambda sensor; E1 ECU no longer supported but existing units may continue. · FF rain tyres now allow Hoosier W3 Radial 185/60R13 front and 205/60R13 rear. · 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. · 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. · 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 2020-10-01 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. 2020-08-01 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. 2020-08-01 AS Dodge Challenger AS Spec Line Clarification #2 #28699aeroaeroAS Dodge Challenger 08-14 rear spoiler: 1GL20RXF replaced with 1GL20TZZAB; 82211606 still permitted. 2020-08-01 FF Clarification regarding Honda LC1 ECU implementation #29135wordingwordingFF Honda LC1 ECU implementation date clarified to pending, contingent on SCCA receiving sufficient support materials. 2020-08-01 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. 2020-07-01 AS Support for R-Type Specification Tires #27450wordingunclearAS class pursuing specified list of eligible tires; list details unclear from text provided. 2020-07-01 AS Spec Tire Request #27519wordingunclearAS class tire eligibility list under development; no specifications changed yet. 2020-07-01 AS Restrictor Plate Change for RP 2011+ Mustang with Coyote Engine #27675wordingunclearAS Coyote Mustang restrictor plate under review for 2021; no change effective yet. 2020-07-01 AS 2005-2009 Restricted Prep 4.6 3V #27908engineaddedengineAS Restricted Prep 4.6 3V now permits conversion to 2 valve configuration. 2020-07-01 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. 2020-07-01 AS Request for Full Preparation Classification for 2010-2014 Camaro #28030wordingunclear2010-2014 Camaro remains classified in AS; no specification changes. 2020-07-01 AS Cylinder Heads #28696wordingunclearAS class cylinder head supplier discontinuation; replacement option pending for 2021 season. 2020-07-01 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. 2020-07-01 AS Request increase rotor diameter #28797wordingunclearunclear 2020-07-01 FA Request to Adjust FB Weight for Stock Engines #29005wordingunclearFA stock engine weight adjustment request denied; modified engines now permitted in FA. 2020-06-01 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. 2020-06-01 FA E&O Transmissions #28832wordingwordingFA transmissions limited to five forward speeds and operational reverse unless Table 2 notes otherwise. 2020-06-01 FA Swift 016 Gurney flap wicker clarification #28884wordingwordingFA Swift 016 Mazda Duratec: clarify Gurney flap wording, dimensions and allowed locations unchanged. 2020-05-01 AS weight adjustments for 2020 season #28785weight -50 lbs 2020-05-01 FA Remove redundant spec line in Table 1 #28720engineremovedengineFA removes Volkswagen 1835cc SOHC engine specification line from Table 1. 2020-05-01 FA E&O general engine rules #28772wordingwordingFA engine rules clarify that blocks and heads must be OEM unless the tables note otherwise; wording only. 2020-04-01 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. 2020-04-01 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. 2020-04-01 FA E&O Formula 3 spec line #28596engineaddedengineFA Formula 3 permitted engine years extended from 1997–2008 to 1997–2017. 2020-04-01 FF E&O FF Kent Engine alternator language #28204engineaddedengineFF Kent Engine alternator becomes optional instead of not required. 2020-03-01 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. 2020-03-01 FF Honda Racing HPD low cost ECU proposal #27563engineaddedengineFF permits HPD LC1 ECU with lambda sensor; E1 ECU no longer supported but existing units may continue. 2020-03-01 FF Update rain tire designation #28443tyres & wheelsaddedtyres & wheelsFF rain tyres now allow Hoosier W3 Radial 185/60R13 front and 205/60R13 rear. 2020-02-01 AS Rear Trailing Arms #28007suspension & brakesaddedsuspension & brakesAS rear trailing arms may be replaced with tubular arms maintaining stock length and axle location purpose only. 2020-02-01 AS Weight reduction for cars running iron heads #28010weightfasterweightAS Ford and GM full prep cars get increased weight reduction from 150 to 200 lbs. 2020-02-01 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. 2020-02-01 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. 2020-01-01 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. 2020-01-01 FA Suggestions for FB/F1000 into FA #27319otherunclearunclear 2020-01-01 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. 2019-12-01 FA Move wheel dimensions from Bodywork subsection to #27493wordingwordingFA wheel diameter and width specifications moved from Bodywork subsection to General section. 2019-12-01 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.
	Virginia International Raceway Runoffs 20192019-10-05	1:59.563Tyler O'Connor · fastest of 14 · top 5 within 1.4s	2:20.474Jonathan Kotyk · fastest of 14 · top 5 within 6.3s	136.2Derek Ketchie	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	-16.574squal +3.375s	88.2%qual 102.8%	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	-4.015squal +14.989s	97.1%qual 112.5%	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	-37.367squal -18.018s	73.4%qual 84.9%
18 rule changes (FF: 3, AS: 4, SM: 4, FA: 7)3 engine · 3 weight · 2 cars added · 1 aero · 1 removed · 5 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. · 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. · 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. · FF Honda Fit cylinder honing increased to 73.315mm and oversize pistons PN 13020-RB7-Z00 now permitted with matching ring packs. · FF intake manifold thermal wrap now permitted if easily removable for inspection; no coating allowed. · FF clarifies coolant and oil catch tank capacity requirements: coolant minimum one U.S. pint, oil minimum one U.S. quart per system. · 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.showhide 2019-10-01 AS Request to add SMG to 9.1.6.B.1 AS Intent #27140cars addedaddedAS Spec Mustang (SMG) added as Restricted Prep class. 2019-10-01 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. 2019-08-31 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. 2019-08-01 AS Request Ride Height Clarification #26598wordingwordingAS class ride height minimum clarified: five inches measured at rocker panel, excluding seams and stock effects. 2019-05-31 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. 2019-05-31 FA Adjust Line N restrictor size and minimum weight #26691weight +30 lbsslowerweightFA Line N minimum weight raised to 1375 lbs. 2019-05-01 FA Add data plate requirement #26707otheraddedFA cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs. 2019-03-01 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. 2019-03-01 SM Request to allow aftermarket fuel filters. #26370otheraddedSM fuel pump and filter now permitted as Mazda or OEM equivalent part. 2019-02-01 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. 2019-02-01 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. 2019-02-01 FA FA 016 weight increase #26063weightslowerweightFA Swift 016 Mazda 2.3 and 2.5 liter minimum weight increases 30 lbs to 1450. 2019-02-01 FF Request for Oversize Honda Fit Pistons #25810enginefasterengineFF Honda Fit cylinder honing increased to 73.315mm and oversize pistons PN 13020-RB7-Z00 now permitted with matching ring packs. 2019-02-01 FF Heat Shield - Fit Intake #26102aeroaddedaeroFF intake manifold thermal wrap now permitted if easily removable for inspection; no coating allowed. 2019-02-01 FF Request catch cans/tanks clarification #26158wordingwordingFF clarifies coolant and oil catch tank capacity requirements: coolant minimum one U.S. pint, oil minimum one U.S. quart per system. 2019-02-01 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. 2019-02-01 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. 2019-02-01 SM Strike Tire Tread Language #26123wordingremovedSM tire tread protrusion language removed from GCR 9.1.7.C.5.
	Sonoma Raceway Runoffs 20182018-10-10	1:41.612Jonathon Kotyk · fastest of 22 · top 5 within 1.7s	1:42.049Jonathon Kotyk · fastest of 22 · top 5 within 1.3s	115.7Denny Renfrow	1:47.782Andrew McDermid · fastest of 12 · top 5 within 1.9s	1:50.345John Heinricy · fastest of 10 · top 5 within 2.3s	105.0Kevin Fandozzi	+8.296squal +6.170s	108.1%qual 106.1%	1:54.355Ken Sutherland · fastest of 48 · top 5 within 0.7s	1:55.278Michael Carter · fastest of 48 · top 5 within 0.3s	102.2Danny Steyn	+13.229squal +12.743s	113.0%qual 112.5%	1:28.176Mirl Swan · fastest of 7 · top 5 within 4.0s	1:29.924Mirl Swan · fastest of 7 · top 5 within 2.6s	144.8Antony Opheim	-12.125squal -13.436s	88.1%qual 86.8%
No rule changes on record between these events
	Indianapolis Motor Speedway Runoffs 20172017-09-25	1:44.601Zach Holden · fastest of 36 · top 5 within 1.2s	1:44.524Jonathon Kotyk · fastest of 36 · top 5 within 0.5s		1:45.220James Jost · fastest of 29 · top 5 within 6.7s	1:51.507Bryan Long · fastest of 28 · top 5 within 0.9s		+6.983squal +0.619s	106.7%qual 100.6%	1:58.306Chris Haldeman · fastest of 86 · top 5 within 0.5s	1:59.100Michael Gagliardo · fastest of 83 · top 5 within 0.6s		+14.576squal +13.705s	113.9%qual 113.1%	1:29.957Sedat Yelkin · fastest of 12 · top 5 within 2.3s	1:31.365Keith Grant · fastest of 12 · top 5 within 1.0s		-13.159squal -14.644s	87.4%qual 86.0%
No rule changes on record between these events
	Mid-Ohio Sports Car Course Runoffs 20162016-09-19	1:29.213Neil Verhagen · fastest of 14 · top 5 within 2.1s	1:30.133Neil Verhagen · fastest of 14 · top 5 within 1.4s		1:30.651Tom Sloe · fastest of 22 · top 5 within 3.6s	1:33.424Edward Hosni · fastest of 20 · top 5 within 1.0s		+3.291squal +1.438s	103.7%qual 101.6%	1:40.514Justin Hille · fastest of 45 · top 5 within 0.3s	1:40.764Michael Carter · fastest of 44 · top 5 within 0.3s		+10.631squal +11.301s	111.8%qual 112.7%	1:14.920Ryan Norman · fastest of 5 · top 5 within 7.0s	1:19.009Ryan Norman · fastest of 5 · top 5 within 4.7s		-11.124squal -14.293s	87.7%qual 84.0%
No rule changes on record between these events
	Daytona International Speedway Runoffs 20152015-09-21	2:02.489Tim Kautz · fastest of 25 · top 5 within 1.1s	2:03.383Rick Payne · fastest of 22 · top 5 within 0.8s		2:01.746Tom Sloe · fastest of 22 · top 5 within 2.6s	2:02.922Andy McDermid · fastest of 19 · top 5 within 2.2s		-0.461squal -0.743s	99.6%qual 99.4%	2:18.661Andrew Carbonell · fastest of 62 · top 5 within 0.6s	2:24.067Todd Lamb · fastest of 59 · top 5 within 0.8s		+20.684squal +16.172s	116.8%qual 113.2%	1:47.758Tyler Hunter · fastest of 10 · top 5 within 3.7s	1:48.162Tyler Hunter · fastest of 8 · top 5 within 5.3s		-15.221squal -14.731s	87.7%qual 88.0%

By track

Track	Events	Typical % of FF	Best	Latest
Road America	4	100.0%	100.0%Runoffs 2020	100.0%Runoffs 2026
Virginia International Raceway	3	100.0%	100.0%Runoffs 2019	100.0%Runoffs 2023
Indianapolis Motor Speedway	2	100.0%	100.0%Runoffs 2017	100.0%Runoffs 2021
Daytona International Speedway	1	100.0%	100.0%Runoffs 2015	100.0%Runoffs 2015
Mid-Ohio Sports Car Course	1	100.0%	100.0%Runoffs 2016	100.0%Runoffs 2016
Sonoma Raceway	1	100.0%	100.0%Runoffs 2018	100.0%Runoffs 2018

About this data

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 FF'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.