BoP Lab / Classes / FM

FM vs FC vs SM vs AS pace at every track

Lap times across years say as much about the weather as the class. % of FM is each class's best lap as a share of FM'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-SpecEPFAvsFC ×FE2FFFM×FPFVFXGT1GT2GTXHPPP2vsSM ×SMXSRF3STLSTUT1T2T3T4Show 50 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: FM 100.0% of FM Joseph Burton-Harris, Daytona International Speedway Runoffs 2015 race · FC 82.6% of FM Robert Allaer, Virginia International Raceway Runoffs 2019 race · SM 100.5% of FM Elivan Goulart, Virginia International Raceway Runoffs 2019 race · AS 91.2% of FM James Jost, Virginia International Raceway Runoffs 2019 race

% of FMLap times

FMFCSMASsolid race · dashed qualifying · slower is lower

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

	Event	FM			FC					SM					AS
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs FM	% of FM	Qual best	Race best	Trap	vs FM	% of FM	Qual best	Race best	Trap	vs FM	% of FM
	Road America Runoffs 20262026-09-28				2:10.686Brandon Dixon · fastest of 10 · top 5 within 4.0s-0.573s (-0.44%)	2:11.389Brandon Dixon · fastest of 10 · top 5 within 2.7s-1.435s (-1.08%)	143.3Dean Kiriluk-1.8 mph (-1.2%)			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%)			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%)
17 rule changes (FC: 2, SM: 2, AS: 13)3 weight · 2 cars added · 2 engine · 1 induction · 1 suspension & brakes · 1 tyres & wheels · 3 wording · 4 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. · 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. · 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. · AS Ford Mustang and Mercury Capri with Restricted Prep engines get 61 mm restrictor, down from 64 mm. · FC USF2000 Tube Frame may now use Hewland LD200 4-speed H-pattern as alternative to Hewland JL-200 5-speed sequential. · FC F2000 Metrik ZF2 minimum weight reduced to 1220 lbs. · 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.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. 2026-07-01 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. 2026-04-01 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. 2026-01-01 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 FC F2000 MZR Spec Line Clarity/Revision Requested #38927otheraddedFC USF2000 Tube Frame may now use Hewland LD200 4-speed H-pattern as alternative to Hewland JL-200 5-speed sequential. 2026-01-01 FC Adjust F2000 Metrik ZF2 weight #39612weight -20 lbsfasterweightFC F2000 Metrik ZF2 minimum weight reduced to 1220 lbs. 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.
	Road America Runoffs 20252025-09-29				2:11.259Brandon Dixon · fastest of 10 · top 5 within 2.7s-0.367s (-0.28%)	2:12.824Brandon Dixon · fastest of 9 · top 5 within 2.3s+1.290s (+0.98%)	145.1Brandon Dixon+0.9 mph (+0.6%)			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%)			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%)
17 rule changes (FC: 2, SM: 4, AS: 11)3 engine · 2 weight · 1 cars added · 1 induction · 7 wording · 3 other · AS Ford Mustang GT 5.0 2018- minimum weight reduced to 3525 lbs. · 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. · 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. · FC tire rule clarified: four dry and four wet tires for Regionals and Majors, eight each for Runoffs; marking and declaration timing adjusted. · FF and FC sequential gearbox weight penalty reduces from 25 lbs to 10 lbs minimum weight addition.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. 2025-06-01 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 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. 2025-01-01 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 FC 9.1.1.10.h. FC Tire Rule #36533wordingwordingFC tire rule clarified: four dry and four wet tires for Regionals and Majors, eight each for Runoffs; marking and declaration timing adjusted. 2024-11-01 FC Change FF/FC Weight with Sequential Gearbox #36651weightfasterweightFF and FC sequential gearbox weight penalty reduces from 25 lbs to 10 lbs minimum weight addition.
	Road America Runoffs 20242024-10-01				2:11.626Timothy Minor · fastest of 10 · top 5 within 1.3s-1.018s (-0.77%)	2:11.534Michael Varacins · fastest of 9 · top 5 within 1.8s-2.074s (-1.55%)	144.2Michael Varacins+1.8 mph (+1.2%)			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%)			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%)
17 rule changes (FC: 2, SM: 4, AS: 11)6 cars added · 2 engine · 1 tyres & wheels · 1 weight · 2 wording · 5 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. · 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. · FC F2000 Metrik ZF2 added as spec line car with Brembo 4-piston calipers and vented rotors permitted. · 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…showhide 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. 2024-04-01 FC Four Pot Calipers #35481cars addedaddedFC F2000 Metrik ZF2 added as spec line car with Brembo 4-piston calipers and vented rotors permitted. 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 FC Please correct omitted punctuation #34890weight
	Virginia International Raceway Runoffs 20232023-09-23				1:50.281Nolan Allaer · fastest of 11 · top 5 within 2.3s+0.386s (+0.35%)	1:51.169Nolan Allaer · fastest of 11 · top 5 within 2.5s-16.690s (-13.05%)	143.5Robert Allaer+2.3 mph (+1.7%)			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%)			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%)
8 rule changes (FC: 3, SM: 1, AS: 4)1 cars added · 1 tyres & wheels · 1 weight · 4 wording · 1 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. · FC tire marking rule clarified: four dry and four wet tires for Regional/Major/Super Tour, eight each for Runoffs; undeclared tire penalty removed. · USF2000 Van Diemen with Mazda MZR LF-DE 2.0L added to FC as spec line car; removed from FX. · FC/FF PE3-8400 ECU tune-file firmware version changes from V3.04.50 to V3.04.35. · SM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore.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. 2023-07-01 FC Review FC Runoffs Tire Marking Rule #34274wordingwordingFC tire marking rule clarified: four dry and four wet tires for Regional/Major/Super Tour, eight each for Runoffs; undeclared tire penalty removed. 2023-06-01 FC USF2000 Van Diemen with Mazda MZR LF-DE 2.0L in FC #34329cars addedaddedUSF2000 Van Diemen with Mazda MZR LF-DE 2.0L added to FC as spec line car; removed from FX. 2023-01-01 FC E&O 9.1.1.B.16.j #33634wordingwordingFC/FF PE3-8400 ECU tune-file firmware version changes from V3.04.50 to V3.04.35. 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.
	Virginia International Raceway Runoffs 20222022-09-24				1:49.895Nolan Allaer · fastest of 12 · top 5 within 1.5s-1.305s (-1.17%)	2:07.859Nolan Allaer · fastest of 13 · top 5 within 3.8s+15.685s (+13.98%)	141.2Tim Minor-0.6 mph (-0.4%)			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%)			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%)
15 rule changes (FC: 5, SM: 1, AS: 9)2 cars added · 2 weight · 1 engine · 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. · FC Zetec ECU: Performance Electronics model designation changed from PE-3 to PE3-8400; monitor firmware updated to V3.04.50. · SM Majors must run authorized Penske shock and mount; Regional competitors not required until further evaluation. · 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. · FC chassis/frame section cleaned up: panels between main tubes must prevent cockpit intrusion; suspension cannot mount to exterior panels; engine/gearbox exempt from load-bearing restrictions. · FC Zetec ECU requirements clarified: Pectel T2 or PE-3 required with specified communications ports and SCCA tune-file/map from official website. · FC composite anti-intrusion panels of non-uniform thickness limited to eight fasteners per side. · FC tire marking requirements clarified: competitor must ensure tires declared, marked, and logged by Tech before qualifying or race use.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. 2022-07-01 FC Add Specification to Performance Electronics ECU for Ford Zetec #32761wordingwordingFC Zetec ECU: Performance Electronics model designation changed from PE-3 to PE3-8400; monitor firmware updated to V3.04.50. 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. 2022-01-01 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. 2022-01-01 FC Clean up Chassis/Frame section #31867wordingwordingFC chassis/frame section cleaned up: panels between main tubes must prevent cockpit intrusion; suspension cannot mount to exterior panels; engine/gearbox exempt from load-bearing restrictions. 2021-12-01 FC Clarify Zetec ECU requirements #31554wordingwordingFC Zetec ECU requirements clarified: Pectel T2 or PE-3 required with specified communications ports and SCCA tune-file/map from official website. 2021-11-01 FC Clarify composite anti-intrusion panel language #31426wordingwordingFC composite anti-intrusion panels of non-uniform thickness limited to eight fasteners per side. 2021-11-01 FC Clarify tire marking requirements #31455wordingwordingFC tire marking requirements clarified: competitor must ensure tires declared, marked, and logged by Tech before qualifying or race use. 2021-10-01 AS Request for adjustable Front Upper Control Arms on 4th Gen F-Body #30457other 2021-10-01 AS Request Pontiac GTO tire size change #30881weight
	Indianapolis Motor Speedway Runoffs 20212021-09-25				1:36.787Trent Walko · fastest of 31 · top 5 within 1.7s+0.451s (+0.47%)	1:36.980Simon Sikes · fastest of 31 · top 5 within 2.0s+0.090s (+0.09%)	141.6Tim Minor			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			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
16 rule changes (FC: 1, SM: 1, AS: 14)7 weight · 3 cars added · 3 engine · 2 wording · 1 other · FC Pinto engine loses 10 lbs to 1190; Pinto aluminum head loses 10 lbs to 1190; Zetec loses 10 lbs to 1210.showhide 2021-06-01 AS Request CTS-V Spec Line Error Correction #30242weight 2021-06-01 AS Request to consolidate SN95 Mustang '94-'04 Mustang spec lines #30428cars added 2021-06-01 AS American Sedan Transmission Rule Change Request #30595weight 2021-06-01 AS Correction to specifications inadvertently deleted #30691wording 2021-06-01 AS weight adjustments #30700weight +50 lbs 2021-04-01 SM Updates - Obsolete Parts & BOP Parts #30438other 2021-03-01 AS AS Mustang LP 4.6 3V Classification Transmission Request #29886weight 2021-03-01 AS Request CF driveshaft on CTS-V for durability improvement #30117engine 2021-03-01 AS Adjustment to model years of 5th generation RP Camaro #30348engine 2021-03-01 FC Request for FC Weight Change #30171weightfasterweightFC Pinto engine loses 10 lbs to 1190; Pinto aluminum head loses 10 lbs to 1190; Zetec loses 10 lbs to 1210. 2021-01-01 AS Request for 2015 -2017 Ford Mustang Spec Line #29514cars added 2021-01-01 AS Request Trunk lid / Rear Hatch clarification #29591wording 2021-01-01 AS Common Weight for CTS-V Tire #29759weight 2021-01-01 AS Correction to specifications inadvertently deleted #30041cars added 2020-12-01 AS Request Additional Engine Options for Dodge Challenger Spec Line #29543engine 2020-12-01 AS Rule simplification spec line communization #29824weight
	Road America Runoffs 20202020-10-02				2:12.644Robert Allaer · fastest of 13 · top 5 within 2.1s	2:13.608Robert Allaer · fastest of 11 · top 5 within 1.2s	142.4Robert Allaer			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			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
22 rule changes (FC: 4, SM: 2, AS: 16)6 engine · 3 suspension & brakes · 3 weight · 2 cars added · 2 induction · 2 tyres & wheels · 1 aero · 1 wording · 2 other · FC ECU maps clarified: SCCA Club or 2013 Pro map required, available on SCCA website; 1.340 restrictor reminder. · FC Zetec engine minimum weight increases 20 lbs to 1220 lbs. · FC allows Eagle #CRS5483F3D connecting rods alongside original Ford; crankshaft replacement clarified to original Ford only. · FC allows Mahle #930169439 piston as new option alongside Ford original, Sealed Power #H872cp, United Engine and Machine #SO2763.showhide 2020-10-01 FC Urgent: SCCA PE3 map unsuitable #29475wordingwordingFC ECU maps clarified: SCCA Club or 2013 Pro map required, available on SCCA website; 1.340 restrictor reminder. 2020-10-01 SM Radiator E&O Clarifications #29294engine 2020-08-01 AS Dodge Challenger AS Spec Line Clarification #28698induction 2020-08-01 AS Dodge Challenger AS Spec Line Clarification #2 #28699aero 2020-08-01 FC Request for weight adjustments to equalize FC competition. #28888weightslowerweightFC Zetec engine minimum weight increases 20 lbs to 1220 lbs. 2020-08-01 SM Modifications to prevent failures of Rear Brake Caliper Pin #28953suspension & brakes 2020-07-01 AS Support for R-Type Specification Tires #27450tyres & wheels 2020-07-01 AS Spec Tire Request #27519tyres & wheels 2020-07-01 AS Restrictor Plate Change for RP 2011+ Mustang with Coyote Engine #27675induction 2020-07-01 AS 2005-2009 Restricted Prep 4.6 3V #27908engine 2020-07-01 AS Request for 2005-2009 Restricted Prep 4.6 3V Parts #27909engine 2020-07-01 AS Request for Full Preparation Classification for 2010-2014 Camaro #28030other 2020-07-01 AS Cylinder Heads #28696engine 2020-07-01 AS Request for Max Rotor Diameter Change #28748suspension & brakes 2020-07-01 AS Request increase rotor diameter #28797other 2020-05-01 AS weight adjustments for 2020 season #28785weight -50 lbs 2020-02-01 AS Rear Trailing Arms #28007suspension & brakes 2020-02-01 AS Weight reduction for cars running iron heads #28010weight 2020-02-01 AS 05-10 Mustang with HR cam classification #28226cars added 2020-02-01 AS 10-15 Camaro Full Prep classification #28227cars added 2019-12-01 FC Request for Better Zetec Connecting Rods #27710engineaddedengineFC allows Eagle #CRS5483F3D connecting rods alongside original Ford; crankshaft replacement clarified to original Ford only. 2019-12-01 FC Add Alternate Piston #27795engineaddedengineFC allows Mahle #930169439 piston as new option alongside Ford original, Sealed Power #H872cp, United Engine and Machine #SO2763.
	Virginia International Raceway Runoffs 20192019-10-05	1:55.124Bryce Cornet · fastest of 8 · top 5 within 2.3s	2:15.816Bryce Cornet · fastest of 8 · top 5 within 4.9s	135.7Bryce Cornet	1:51.200Robert Allaer · fastest of 10 · top 5 within 3.1s	1:52.174Robert Allaer · fastest of 9 · top 5 within 2.7s	141.8Robert Allaer	-23.642squal -3.924s	82.6%qual 96.6%	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	+0.643squal +19.428s	100.5%qual 116.9%	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	-11.916squal +7.814s	91.2%qual 106.8%
10 rule changes (FC: 2, SM: 4, AS: 4)2 weight · 1 cars added · 1 engine · 1 suspension & brakes · 1 tyres & wheels · 3 wording · 1 other · FC Wiseco piston and Crower rod part numbers updated; minimum weight unchanged at 976 grams. · FC Wiseco piston and connecting rod minimum weight corrected to 976 grams.showhide 2019-10-01 AS Request to add SMG to 9.1.6.B.1 AS Intent #27140other 2019-08-01 AS Request Ride Height Clarification #26598suspension & brakes 2019-05-31 AS Request to Revert to 2017 Weights #25885weight 2019-05-01 FC E&O Wiseco piston and Crower connecting rod #26659wordingwordingFC Wiseco piston and Crower rod part numbers updated; minimum weight unchanged at 976 grams. 2019-03-01 SM Request to allow aftermarket fuel filters. #26370wording 2019-02-01 AS SMG Mustang eligibility in American sedan #26224cars added 2019-02-01 SM Request 99-00 replacement Wire harnesses #25602engine 2019-02-01 SM Organize and Clarify 9.1.7.C.1.o. #25913weight 2019-02-01 SM Strike Tire Tread Language #26123tyres & wheels 2019-01-01 FC Correct Wiseco piston and connecting rod #25809wordingwordingFC Wiseco piston and connecting rod minimum weight corrected to 976 grams.
	Sonoma Raceway Runoffs 20182018-10-10	1:37.598Bryce Cornet · fastest of 13 · top 5 within 0.9s	1:37.909Bryce Cornet · fastest of 12 · top 5 within 1.3s	124.1Melvin David Kemper Jr	1:32.571Timothy de Silva · fastest of 16 · top 5 within 1.8s	1:34.053Mitch Egner · fastest of 12 · top 5 within 1.6s	133.1Robert Armington	-3.856squal -5.027s	96.1%qual 94.8%	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	+17.369squal +16.757s	117.7%qual 117.2%	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	+12.436squal +10.184s	112.7%qual 110.4%
No rule changes on record between these events
	Indianapolis Motor Speedway Runoffs 20172017-09-25	1:41.231Jarret Voorhies · fastest of 16 · top 5 within 1.7s	1:41.146Jarret Voorhies · fastest of 16 · top 5 within 1.2s		1:36.336Austin McCusker · fastest of 14 · top 5 within 2.3s	1:36.890Tim Minor · fastest of 14 · top 5 within 3.8s		-4.256squal -4.895s	95.8%qual 95.2%	1:58.306Chris Haldeman · fastest of 86 · top 5 within 0.5s	1:59.100Michael Gagliardo · fastest of 83 · top 5 within 0.6s		+17.954squal +17.075s	117.8%qual 116.9%	1:45.220James Jost · fastest of 29 · top 5 within 6.7s	1:51.507Bryan Long · fastest of 28 · top 5 within 0.9s		+10.361squal +3.989s	110.2%qual 103.9%
No rule changes on record between these events
	Mid-Ohio Sports Car Course Runoffs 20162016-09-19	1:26.043Jacob Loomis · fastest of 8 · top 5 within 3.1s	1:27.922Jacob Loomis · fastest of 8 · top 5 within 2.7s		1:21.962John LaRue · fastest of 7 · top 5 within 2.6s	1:22.049Nigel Saurino · fastest of 7 · top 5 within 3.0s		-5.873squal -4.081s	93.3%qual 95.3%	1:40.514Justin Hille · fastest of 45 · top 5 within 0.3s	1:40.764Michael Carter · fastest of 44 · top 5 within 0.3s		+12.842squal +14.471s	114.6%qual 116.8%	1:30.651Tom Sloe · fastest of 22 · top 5 within 3.6s	1:33.424Edward Hosni · fastest of 20 · top 5 within 1.0s		+5.502squal +4.608s	106.3%qual 105.4%
No rule changes on record between these events
	Daytona International Speedway Runoffs 20152015-09-21	1:57.804Joseph Burton-Harris · fastest of 10 · top 5 within 2.3s	1:58.029Joseph Burton-Harris · fastest of 10 · top 5 within 1.7s		1:54.477Yufeng Luo · fastest of 11 · top 5 within 2.5s	1:55.135Yufeng Luo · fastest of 10 · top 5 within 2.1s		-2.894squal -3.327s	97.5%qual 97.2%	2:18.661Andrew Carbonell · fastest of 62 · top 5 within 0.6s	2:24.067Todd Lamb · fastest of 59 · top 5 within 0.8s		+26.038squal +20.857s	122.1%qual 117.7%	2:01.746Tom Sloe · fastest of 22 · top 5 within 2.6s	2:02.922Andy McDermid · fastest of 19 · top 5 within 2.2s		+4.893squal +3.942s	104.1%qual 103.3%

By track

Track	Events	Typical % of FM	Best	Latest
Road America	4	0 of 4 with FM
Virginia International Raceway	3	100.0%1 of 3 with FM	100.0%Runoffs 2019	100.0%Runoffs 2019
Indianapolis Motor Speedway	2	100.0%1 of 2 with FM	100.0%Runoffs 2017	100.0%Runoffs 2017
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 FM'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.