BoP Lab / Classes / AS
AS vs FE2 vs P2 pace at every track
Lap times across years say as much about the weather as the class. % of AS is each class's best lap as a share of AS's on the same day, so the conditions drop out: 100% is level, less is quicker, and a move in it is the class getting faster or slower against the field.
Closest to the field: AS 100.0% of AS Andy McDermid, Daytona International Speedway Runoffs 2015 race · FE2 86.6% of AS Flinn Lazier, Sonoma Raceway Runoffs 2018 race · P2 82.4% of AS Tim Day Jr, Sonoma Raceway Runoffs 2018 qualifying
| Event | AS | FE2 | P2 | ||||||||||||
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| Qual best | Race best | Trap | Qual best | Race best | Trap | vs AS | % of AS | Qual best | Race best | Trap | vs AS | % of AS | |||
| Road America Runoffs 20262026-09-28 | 2:26.911Andrew McDermid · fastest of 8 · top 5 within 3.4s+0.119s (+0.08%) | 2:28.471Andrew McDermid · fastest of 8 · top 5 within 2.4s-0.761s (-0.51%) | 151.0Andrew McDermid-0.6 mph (-0.4%) | 2:12.326Franklin Futrelle · fastest of 8 · top 5 within 1.9s-0.149s (-0.11%) | 2:11.881Franklin Futrelle · fastest of 8 · top 5 within 1.6s-1.458s (-1.09%) | 143.5Steve Whitston-5.5 mph (-3.7%) | -16.590squal -14.585s | 88.8%qual 90.1% | 2:10.606Greg Gyann · fastest of 11 · top 5 within 5.3s+3.201s (+2.51%) | 2:09.441Mike Reupert · fastest of 11 · top 5 within 4.2s+1.119s (+0.87%) | 155.0Matt Strand+2.4 mph (+1.6%) | -19.030squal -16.305s | 87.2%qual 88.9% | ||
14 rule changes (AS: 13, FE2: 1)3 cars added · 2 engine · 2 weight · 1 induction · 1 suspension & brakes · 1 tyres & wheels · 2 wording · 2 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. · 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. · 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. · 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. · FE and FE2 Enterprise bubble tail part WM138014 now allowed; FE2 must use this configuration only.show
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| Road America Runoffs 20252025-09-29 | 2:26.792Andrew McDermid · fastest of 11 · top 5 within 3.9s+0.214s (+0.15%) | 2:29.232Gregory Eaton · fastest of 10 · top 5 within 4.0s+2.803s (+1.91%) | 151.5Andrew McDermid+1.9 mph (+1.3%) | 2:12.475Franklin Futrelle · fastest of 11 · top 5 within 1.4s+0.969s (+0.74%) | 2:13.339Franklin Futrelle · fastest of 10 · top 5 within 0.6s+0.591s (+0.45%) | 149.0Steve Whitston+3.7 mph (+2.6%) | -15.893squal -14.317s | 89.4%qual 90.2% | |||||||
13 rule changes (AS: 11, FE2: 1, P2: 1)3 engine · 2 weight · 1 cars added · 1 induction · 3 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. · 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. · 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. · FE2 allows pre-approved driver safety and comfort seat and control modifications for drivers with disabilities, per logbook. · 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. · P2 2000 cc Pinto engine car minimum weight set to 1335 lbs.show
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| Road America Runoffs 20242024-10-01 | 2:26.578Gregory Eaton · fastest of 18 · top 5 within 2.6s-0.467s (-0.32%) | 2:26.429Gregory Eaton · fastest of 18 · top 5 within 2.5s-1.239s (-0.84%) | 149.6Gregory Eaton+0.4 mph (+0.3%) | 2:11.506Porter Aiken · fastest of 18 · top 5 within 0.5s-1.300s (-0.98%) | 2:12.748Porter Aiken · fastest of 17 · top 5 within 2.0s-0.523s (-0.39%) | 145.3Porter Aiken+1.9 mph (+1.3%) | -13.681squal -15.072s | 90.7%qual 89.7% | 2:07.405Bart Wolf · fastest of 14 · top 5 within 3.0s-1.109s (-0.86%) | 2:08.322Bart Wolf · fastest of 13 · top 5 within 0.6s-1.471s (-1.13%) | 152.5Lucian Pancea-0.6 mph (-0.4%) | -18.107squal -19.173s | 87.6%qual 86.9% | ||
16 rule changes (AS: 11, P2: 5)5 cars added · 2 engine · 1 tyres & wheels · 4 wording · 4 other · AS Mustang GT 05-14 Restricted Prep and 2018- gain alternate transmission ratio options. · 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. · P2 Spec Line E engine notes clarify oil system, ECU, and exhaust remain unrestricted; wording only. · P2 FIA Group CN notes clarify V de V European Proto Endurance Challenge bodywork, rear diffuser, wing, wheels, assisted shifting allowed; regulations link provided. · 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… · P2 AMAC and related cars: clarified B.1 modified engine range to 2008 and older stock engines only, with 38mm restrictor and 1025 lbs minimum weight. · P2 Suzuki GSX-R1000 engine: 2007–2008 crankcase 11300-21860 may be replaced with 2016–2019 GSX-S1000 part 11301-04840. · P2 Table 1 engine date ranges clarified: Stock Engine replaced with specific marques Suzuki, Yamaha, Honda, BMW for 2009-newer and 2008-older rows.show
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| Virginia International Raceway Runoffs 20232023-09-23 | 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%) | 1:50.665Charles Russell Turner · fastest of 26 · top 5 within 2.3s-0.188s (-0.17%) | 1:51.098Franklin Futrelle · fastest of 19 · top 5 within 1.4s-20.947s (-15.86%) | 141.3Franklin Futrelle-0.6 mph (-0.4%) | -13.022squal -12.417s | 89.5%qual 89.9% | 1:48.590Greg Gyann · fastest of 12 · top 5 within 1.7s+1.024s (+0.95%) | 1:48.829Lucian Pancea · fastest of 11 · top 5 within 0.9s-27.005s (-19.88%) | 150.9Lucian Pancea-0.2 mph (-0.2%) | -15.291squal -14.492s | 87.7%qual 88.2% | ||
12 rule changes (AS: 4, P2: 8)2 engine · 1 cars added · 1 tyres & wheels · 7 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. · P2 minimum side body height must equal front axle centerline height, viewed from side. · P2 closed cockpit single seat cars now prohibited unless Table 1 spec line permits. · P2 engine table spec line B.1 redundant effective date language removed and table updated. · P2 motorcycle restrictor reduced 35mm to 34mm for 2011+ Kawasaki; minimum weights increased to 1100 lbs for 2009+ engines; cockpit length corrected to 23.622 inches. · Sebeco NP01-EVO and Elan NP01 added to P2 with Mazda 2.0L MZR, no restrictor required, 1600 lb minimum weight. · P2 Radical SR3/SR4, Cup, Club Sport, Pro-Sport, PR6: assisted shifting clarified from A-assisted to Aassisted; Cup engine restrictor changed from Unrestricted to Not required. · P2 chassis now allows composite materials partially installed; anti-intrusion panels attachment simplified; Stohr and converted models clarified.show
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| Virginia International Raceway Runoffs 20222022-09-24 | 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%) | 1:50.853Charles Russell Turner · fastest of 25 · top 5 within 1.1s-0.209s (-0.19%) | 2:12.045Jason Conzo · fastest of 22 · top 5 within 1.8s+19.891s (+17.74%) | 141.9Eric Cruz-0.6 mph (-0.5%) | +7.467squal -11.309s | 106.0%qual 90.7% | 1:47.566Tim Day Jr · fastest of 12 · top 5 within 3.0s-1.545s (-1.42%) | 2:15.834Greg Gyann · fastest of 12 · top 5 within 10.1s+25.576s (+23.20%) | 151.1Robert Iversen+1.8 mph (+1.2%) | +11.256squal -14.596s | 109.0%qual 88.1% | ||
19 rule changes (AS: 9, P2: 10)3 cars added · 3 weight · 1 engine · 1 tyres & wheels · 9 wording · 2 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. · P2 chassis construction clarified: full composite allowed; partial composite must roll without composite parts installed. · P2 classification wording cleaned up in GCR section 9.1.8.C and GCR contents. · P2 Oldsmobile cam rules correct spelling from 'after market' to 'aftermarket' in two sections. · P2 adds Beasley B2 at 1350 lbs with Mazda 12A, 40.5mm venturi, and up to 16.5in wing chord. · P2 wings: terminology change from 'cord' to 'chord', and 'only' removed from Bobsy and Jondal notes. · P2 Converted F5 cars renamed F500, must retain F500 suspension, minimum width 55 inches. · P2 motorcycle engines gain 5cc to 1505cc max, two-stroke gains 5cc to 1205cc max, automotive engines add 50 lbs minimum weight to 1350 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. · P2 Control Area definition clarified: rectangular zone from rear edge of front tires to front edge of rear tires, full car width. · P2 specification line B.1 engine table entry amended; details of change not provided in excerpt. · P2 Control Area definition clarified: rear tire edge and front tire edge bounds, car's lower surface width, floor extensions and aerodynamic attachments included, vertical structures prohibited. · 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.show
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| Indianapolis Motor Speedway Runoffs 20212021-09-25 | 1:50.427Drew Cattell · fastest of 31 · top 5 within 1.9s+5.207s (+4.95%) | 1:50.606Gregory Eaton · fastest of 28 · top 5 within 1.7s-0.901s (-0.81%) | 153.8James Jost | 1:36.395Max Grau · fastest of 28 · top 5 within 0.7s | 1:36.655Max Grau · fastest of 28 · top 5 within 0.7s | 146.2Gray Fowler | -13.951squal -14.032s | 87.4%qual 87.3% | 1:33.235Tim Day Jr · fastest of 16 · top 5 within 3.3s+1.409s (+1.53%) | 1:35.322Tim Day Jr · fastest of 10 · top 5 within 4.8s+2.841s (+3.07%) | 150.3Robert Iversen | -15.284squal -17.192s | 86.2%qual 84.4% | ||
22 rule changes (AS: 14, P2: 8)6 cars added · 4 engine · 3 weight · 8 wording · 1 other · P2 CN Honda K20A-FD2 engine rebuild clarified: balancing, porting, polishing prohibited; valve jobs and honing must follow factory procedures. · P2 Converted F5 cars must retain F5 suspension and meet P2 non-spec requirements except minimum width is 55 inches. · P2 minimum body width clarified: cannot extend inward beyond vertical plane through tire centerlines. · 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. · P2 tonneau covers now allowed to meet minimum dimensions; cockpit equipment attachment wording clarified. · P2 removes effective date 01/01/2021 from six car spec lines in Table 1. · P2 engine specs B.1, B.2, B.3 limited to maximum 4 valves per cylinder. · 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. · P2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front, 14–15 rear wheel width. · 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. · 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. · P2 motorcycle-engine cars: 2009+ stock 37mm restrictor, 2008- stock 35mm, modified 1075 lbs. Honda K20A 50mm restrictor. Various spec cars: restrictors increased or decreased 0.5–3mm.show
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| Road America Runoffs 20202020-10-02 | 2:27.045Gregory Eaton · fastest of 18 · top 5 within 0.6s | 2:27.668Gregory Eaton · fastest of 15 · top 5 within 1.5s | 149.2Gregory Eaton | 2:12.806Scott Rettich · fastest of 25 · top 5 within 0.6s | 2:13.271Owen McAllister · fastest of 23 · top 5 within 0.7s | 143.4Owen McAllister | -14.397squal -14.239s | 90.3%qual 90.3% | 2:08.514Robert Iversen · fastest of 12 · top 5 within 3.0s | 2:09.793Robert Iversen · fastest of 12 · top 5 within 3.9s | 153.1Robert Iversen | -17.875squal -18.531s | 87.9%qual 87.4% | ||
24 rule changes (AS: 16, FE2: 2, P2: 6)4 engine · 3 cars added · 3 weight · 2 aero · 1 induction · 1 suspension & brakes · 8 wording · 2 other · FE2 oil cooler rule clarified: Setrab 50-625-7612 or any cooler with max core 13 inches wide by 6.5 inches high allowed. · P2 rear wing rules clarified: standard wing 6×12 inches, end plates 14-inch square; alternate 1-meter formula wing 110cm wide, 9×18 inches, end plates 14×18 inches. · 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. · 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 · Elan NP01 added to P2 Table 1 as Spec Line car with 2000cc displacement and 42mm restrictor. · P2 Enterprises Sports Racer now permits 55mm flat plate intake restrictor Part # WM303013 as alternative to SIR. · P2 Enterprise Sports Racer 2.3L engine must use SIR or Flat Plate restrictor meeting peak horsepower, sized in whole or 0.5mm increments. · P2 electronic throttle control wording clarified: ETC permitted if stock ECU throttle pedal activates original throttle shaft mechanism. · 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. · P2 adds BMW to permitted motorcycle-based engines alongside Kawasaki, Suzuki, Yamaha, Honda. · FE minimum weight rises to 1270 lbs; FE2 minimum weight rises to 1270 lbs; new spring options added; tire warmers prohibited.show
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| Virginia International Raceway Runoffs 20192019-10-05 | 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 | 1:51.062Liam Snyder · fastest of 20 · top 5 within 1.3s | 1:52.154Liam Snyder · fastest of 19 · top 5 within 0.7s | 142.6Robert Vanman | -11.746squal -11.876s | 90.5%qual 90.3% | 1:49.111Robert Iversen · fastest of 14 · top 5 within 0.8s | 1:50.258Greg Gyann · fastest of 13 · top 5 within 0.4s | 149.4Robert Iversen | -13.642squal -13.827s | 89.0%qual 88.8% | ||
13 rule changes (AS: 4, P2: 9)4 engine · 3 cars added · 2 weight · 1 induction · 3 wording · AS Spec Mustang (SMG) added as Restricted Prep class. · P2 Honda K20A-FD2 non-composite chassis intake restrictor note clarified; restrictor implementation date removed. · P2 motorcycle engines: Stock restrictor to 35mm, Modified to 34mm; weights up to 1025 and 1125 lbs respectively. B.5 restrictor to 33mm, weight to 1185 lbs. · AS class ride height minimum clarified: five inches measured at rocker panel, excluding seams and stock effects. · P2 cars limited to power application on maximum two wheels. · P2 Enterprise minimum weight increased to 1375 lbs.; peak horsepower of sealed ESR engine reduced per CRB specification. · AS Ford Mustang 79-93 non-Cobra drops 100 lbs to 3150; over 313 CID Cobra drops 100 lbs to 3450. · P2 stock and modified engines get smaller restrictors (35.0mm, 34.0mm, 33.0mm) and heavier minimums (1025, 1125, 1185 lbs). · P2 Line A.1 restrictor reduced from 40mm to 38mm. · AS adds Spec Mustang SMG classification with 107.1 wheelbase, 3.73 gears, 355mm front and 300mm rear brakes. · P2 Spec Line cars now allow 1345cc Hayabusa stock engines at 1050 lb minimum with 30mm restrictor. · P2 Group CN Honda K20A-FD2 55mm intake restrictor implementation delayed from 1 January to 3 March 2019. · P2 Honda K20A-FD2 Group CN must use stock intake manifold, 64mm throttle, 55mm restrictor at 1500 lbs minimum.show
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| Sonoma Raceway Runoffs 20182018-10-10 | 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 | 1:35.040Flinn Lazier · fastest of 9 · top 5 within 1.5s | 1:35.563Flinn Lazier · fastest of 9 · top 5 within 1.7s | 126.8Scott Rettich | -14.782squal -12.742s | 86.6%qual 88.2% | 1:28.784Tim Day Jr · fastest of 17 · top 5 within 5.0s | 1:32.071Chuck Bona · fastest of 18 · top 5 within 0.9s | 144.4Tim Day Jr | -18.274squal -18.998s | 83.4%qual 82.4% | ||
| No rule changes on record between these events | |||||||||||||||
| Indianapolis Motor Speedway Runoffs 20172017-09-25 | 1:45.220James Jost · fastest of 29 · top 5 within 6.7s | 1:51.507Bryan Long · fastest of 28 · top 5 within 0.9s | 1:31.826Jeff Shafer · fastest of 26 · top 5 within 4.9s | 1:32.481Jeff Shafer · fastest of 24 · top 5 within 3.8s | -19.026squal -13.394s | 82.9%qual 87.3% | |||||||||
| No rule changes on record between these events | |||||||||||||||
| Mid-Ohio Sports Car Course Runoffs 20162016-09-19 | 1:30.651Tom Sloe · fastest of 22 · top 5 within 3.6s | 1:33.424Edward Hosni · fastest of 20 · top 5 within 1.0s | 1:20.188Jeff Shafer · fastest of 18 · top 5 within 4.0s | 1:20.904Jeff Shafer · fastest of 16 · top 5 within 2.2s | -12.520squal -10.463s | 86.6%qual 88.5% | |||||||||
| No rule changes on record between these events | |||||||||||||||
| Daytona International Speedway Runoffs 20152015-09-21 | 2:01.746Tom Sloe · fastest of 22 · top 5 within 2.6s | 2:02.922Andy McDermid · fastest of 19 · top 5 within 2.2s | 1:51.825Chris Farrell · fastest of 17 · top 5 within 3.6s | 1:52.355Jeff Shafer · fastest of 17 · top 5 within 2.8s | -10.567squal -9.921s | 91.4%qual 91.9% | |||||||||
By track
| Track | Events | Typical % of AS | 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 AS's best on the same day: the weather and the day cancel out, so one figure compares across years where lap times cannot; a class that suits one track more than another still reads differently there. It still moves when the yardstick's own balance changes or its field thins, and an event the yardstick did not run has no point. A best from fewer than three cars is greyed. The rule changes that took effect between two events are folded between their rows.