BoP Lab / Classes / P1
P1 vs P2 vs SM vs FF pace at every track
Lap times across years say as much about the weather as the class. % of P1 is each class's best lap as a share of P1'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.
Quickest here: P1 1:17.308 James Devenport, Runoffs 2016 qualifying · P2 1:20.188 Jeff Shafer, Runoffs 2016 qualifying · SM 1:40.514 Justin Hille, Runoffs 2016 qualifying · FF 1:29.213 Neil Verhagen, Runoffs 2016 qualifying
| Event | P1 | P2 | SM | FF | ||||||||||||||||
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| Qual best | Race best | Trap | Qual best | Race best | Trap | vs P1 | % of P1 | Qual best | Race best | Trap | vs P1 | % of P1 | Qual best | Race best | Trap | vs P1 | % of P1 | |||
| Road America Runoffs 20262026-09-28 | 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%) | 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%) | 2:23.047David 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%) | |||||||||||
4 rule changes (SM: 2, FF: 2)1 tyres & wheels · 2 wording · 1 other · 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. · SM/SMX part number 0000-10-6900 replaced with 0000-06-5016-KT in GCR 9.1.7.C.1.j.1.c. · 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.show
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| Road America Runoffs 20252025-09-29 | 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%) | 2:24.905Jonathan 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%) | ||||||||||||||
9 rule changes (P2: 1, SM: 4, FF: 4)2 tyres & wheels · 2 weight · 1 engine · 3 wording · 1 other · 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. · 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. · FF adds alternative tire options for older cars with rocker arm or outboard suspension: bias ply slicks or VFF radials. · P2 2000 cc Pinto engine car minimum weight set to 1335 lbs. · 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.show
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| Road America Runoffs 20242024-10-01 | 2:00.476Chip Romer · fastest of 12 · top 5 within 1.5s-0.625s (-0.52%) | 2:00.418Matt Romer · fastest of 9 · top 5 within 2.1s-1.452s (-1.19%) | 168.3Jason Miller+8.7 mph (+5.4%) | 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%) | +7.904squal +6.929s | 106.6%qual 105.8% | 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%) | +41.068squal +40.630s | 134.1%qual 133.7% | 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%) | +21.639squal +22.076s | 118.0%qual 118.3% | ||
17 rule changes (P1: 6, P2: 5, SM: 4, FF: 2)3 engine · 2 weight · 11 wording · 1 other · FF EGR blanking plate rule clarified: VTEC activation valve must be retained and functioning, no modifications permitted. · 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. · P1 engine approval process wording clarified; unspecified engines need case-by-case Board review. · 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. · P1 removes redundant effective date language from ECU stall prohibition rule. · P1 Honda K20A-FD2 engine terminology corrected from 'spec' to proper series designation; FIA certification documentation requirement removed. · FF Honda Fit gains Fast Forward oversize piston ring option PN FF800-100 as alternative to Riken or Nippon. · P1 Engine Table line H restrictor grows to 32 mm, weight rises to 1450 lbs; line I restrictor to 31 mm, weight to 1475 lbs. · P1 Group CN Honda K20A-FD2 removes engine modification restrictions; CRB may add intake restrictor if needed. · 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 | 1:42.602Todd Vanacore · fastest of 10 · top 5 within 0.9s+1.001s (+0.99%) | 1:44.329Todd Vanacore · fastest of 9 · top 5 within 0.7s-9.766s (-8.56%) | 158.5Jason Miller+1.2 mph (+0.8%) | 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%) | +4.500squal +5.988s | 104.3%qual 105.8% | 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%) | +31.900squal +32.384s | 130.6%qual 131.6% | 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%) | +16.254squal +16.647s | 115.6%qual 116.2% | ||
17 rule changes (P1: 7, P2: 8, SM: 1, FF: 1)4 engine · 2 aero · 1 cars added · 1 weight · 9 wording · P1 SIR testing: vehicle deemed compliant if it stalls within 3 seconds of the stall test. · P1 intake restrictor rule clarified: flat plate, venturi, or Single Inlet Restrictor required; all intake air must pass through. · P1 ducted air rule clarified: top-exit ducted air must pass through heat exchanger, except cockpit opening and engine bay vents. · 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. · P1 aero height limit, front/rear overhang, and cockpit dimensions corrected to metric-inch equivalents. · 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. · FF Honda Fit engine adds Fast Forward part number alternatives for intake, exhaust, oil system, and scavenge pump components. · P1 suspension covers must have symmetrical upper and lower surfaces, no airfoil cross-sections or angled downforce. · 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. · SM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore. · P1 aerodynamic devices may not extend more than 1cm below lower surfaces rear of front axle; body panels covering suspension must not be airfoil-shaped or create downforce. · P1 forced induction prohibited: turbocharging and supercharging not allowed.show
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| Virginia International Raceway Runoffs 20222022-09-24 | 1:41.601Todd Slusher · fastest of 9 · top 5 within 2.3s-1.073s (-1.05%) | 1:54.095John Mcaleer · fastest of 9 · top 5 within 1.4s+10.597s (+10.24%) | 157.2Jason Miller+1.3 mph (+0.8%) | 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%) | +21.739squal +5.965s | 119.1%qual 105.9% | 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%) | +25.012squal +33.063s | 121.9%qual 132.5% | 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%) | +24.263squal +17.614s | 121.3%qual 117.3% | ||
14 rule changes (P1: 3, P2: 10, SM: 1)2 engine · 1 cars added · 1 weight · 9 wording · 1 other · P1 motorcycle-based engines with individual throttle bodies must use flat plate intake restrictors within 4 inches of primary butterfly. · P1 bodywork rules clarified: cycle fenders prohibited, side body minimum height at front axle centerline, air ducting for downforce banned. · 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. · SM Majors must run authorized Penske shock and mount; Regional competitors not required until further evaluation. · 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. · P1 2-cycle 6-cylinder maximum displacement increases to 1725 cc, restrictor shrinks to 40mm, minimum weight drops to 1275 lbs. · 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.show
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| Indianapolis Motor Speedway Runoffs 20212021-09-25 | 1:29.011Lee Alexander · fastest of 13 · top 5 within 2.5s-1.783s (-1.96%) | 1:29.225Lee Alexander · fastest of 12 · top 5 within 3.5s-2.274s (-2.49%) | 160.1Jason Miller | 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 | +6.097squal +4.224s | 106.8%qual 104.7% | 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 | +29.612squal +28.684s | 133.2%qual 132.2% | 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 | +26.451squal +15.348s | 129.6%qual 117.2% | ||
23 rule changes (P1: 11, P2: 8, SM: 1, FF: 3)4 engine · 3 cars added · 15 wording · 1 other · P1 creates separate spec lines H and I for 2000cc and 2300cc engines at 1400 and 1445 lbs minimum weight respectively. · P1 Staudacher may run 950 lbs minimum weight with 38.5mm flat plate intake restrictor, removing prior weight-linked restrictor rule. · P2 CN Honda K20A-FD2 engine rebuild clarified: balancing, porting, polishing prohibited; valve jobs and honing must follow factory procedures. · P1 adds 1355cc motorcycle-based engine line C at 1075 lbs minimum weight, no restrictor required. · 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. · P1 cockpit opening section allows tonneau covers to meet minimum dimensions; wording clarified on equipment attachment. · P1 Staudacher 1005cc homologated before 1-1-2014 may run 38.5mm flat plate intake restrictor at 950 lbs minimum weight. · P1 Spec Line C: FPIR not required at 1150 lbs, 1355cc max may run without FPIR at 1075 lbs. Spec Line G: up to 2000cc runs 30mm SIR at 1400 lbs, 2300cc runs 30mm SIR at 1445 lbs. · P1 classes B, C, D maximum valves per cylinder set to 4, previously unspecified. · 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. · FF block relief permitted only as needed to fit an allowed crankshaft. · P1 Spec Line A clarifies carburetor induction only, one per cylinder, balance tubes not allowed. · P1 Spec Line H notes clarify peripheral port or bridgeport allowed; wording only. · SM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture. · P1 Elan DP02-spec Mazda MZR sealed engine option removed effective 3/1/2021. · P1 Engine Table Spec Lines C and G change 'inlet restrictor' to 'intake restrictor' terminology. · P2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front, 14–15 rear wheel width. · 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. · 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 | 2:01.101James French · fastest of 18 · top 5 within 1.1s | 2:01.870James French · fastest of 17 · top 5 within 1.8s | 159.7David Locke | 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 | +7.923squal +7.413s | 106.5%qual 106.1% | 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 | +41.878squal +41.108s | 134.4%qual 133.9% | 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 | +22.398squal +21.815s | 118.4%qual 118.0% | ||
16 rule changes (P1: 4, P2: 6, SM: 2, FF: 4)4 engine · 2 induction · 1 aero · 1 cars added · 1 removed · 1 suspension & brakes · 1 tyres & wheels · 4 wording · 1 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. · 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. · 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. · Elan NP01 added to P2 Table 1 as Spec Line car with 2000cc displacement and 42mm restrictor. · P1 intake manifolds unrestricted unless engine requires flat plate restrictor; no plenums or balance pipes on restricted individual runner manifolds. · P2 Enterprises Sports Racer now permits 55mm flat plate intake restrictor Part # WM303013 as alternative to SIR. · FF Kent Engine alternator becomes optional instead of not required. · P2 Enterprise Sports Racer 2.3L engine must use SIR or Flat Plate restrictor meeting peak horsepower, sized in whole or 0.5mm increments. · 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. · P2 electronic throttle control wording clarified: ETC permitted if stock ECU throttle pedal activates original throttle shaft mechanism. · P1 sealed 2.0L Elan DP02-spec Mazda option removal date extended from 1/1/2020 to 1/1/2021. · P1 sealed 2.0 MZR engine removed effective 1/1/2020; competitors may run it under Spec Line G. · P1 Spec Line F: Restricted 2.0L Group becomes CN-spec Honda K20A-FD2, 2000cc, 1400 lbs minimum. · P2 adds BMW to permitted motorcycle-based engines alongside Kawasaki, Suzuki, Yamaha, Honda.show
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| Virginia International Raceway Runoffs 20192019-10-05 | 1:42.674Todd Slusher · fastest of 14 · top 5 within 1.5s | 1:43.498Todd Slusher · fastest of 13 · top 5 within 1.0s | 155.9Jim Devenport | 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 | +6.760squal +6.437s | 106.5%qual 106.3% | 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 | +32.961squal +31.878s | 131.8%qual 131.0% | 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 | +36.976squal +16.889s | 135.7%qual 116.4% | ||
30 rule changes (P1: 14, P2: 9, SM: 4, FF: 3)5 engine · 2 cars added · 1 aero · 1 induction · 1 weight · 17 wording · 3 other · 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. · P1 traction control prohibited. · P1 permits mechanical, solenoid, and air-shifters; prohibits electronic pre-selection and multi-wheel power. · P1 minimum bodywork height rule moved and restated with new 115cm aerodynamic part height limit. · P1 consolidates fender louver rules into one section; removes duplicate allowance for louvers and clarifies brake and engine air ducts are permitted. · 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. · P1 anti-intrusion panels now allowed anywhere on chassis sides instead of specified locations. · P1 bodywork wording clarified: comfort and safety for driver and passenger or driver only. · P1 Engine Table reference cleaned up; no performance change. · P1 Mazda Renesis Rotary engine spec line removed from Engine Table. · P1 Staudacher and Honda K20A-FD2 engine table wording clarified; no performance change. · P1 closed cockpit single-seat cars remain prohibited; rule moved from subsection J.5 to B.4. · 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. · SM fuel pump and filter now permitted as Mazda or OEM equivalent part. · 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. · P1 engine table reference corrected from 'above' to 'below'; ETC/FBW/DBW throttle wording clarified on sensor and fail-safe requirements. · 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. · P1 removes TIR inlet restrictor option; deletes requirement for single turbo/supercharger unit with single restrictor. · P1 CN-spec Honda K20A-FD2 clarified: stock OEM parts required, no machining allowed. · P1 engine rules correct grammar and remove head designs from specification table. · 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 | 1:27.714Todd Slusher · fastest of 19 · top 5 within 2.1s | 1:28.786Perry Richardson · fastest of 19 · top 5 within 0.9s | 144.0Johnnie Crean | 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 | +3.285squal +1.070s | 103.7%qual 101.2% | 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 | +26.492squal +26.641s | 129.8%qual 130.4% | 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 | +13.263squal +13.898s | 114.9%qual 115.8% | ||
| No rule changes on record between these events | ||||||||||||||||||||
| Indianapolis Motor Speedway Runoffs 20172017-09-25 | 1:30.794Jim Devenport · fastest of 19 · top 5 within 2.8s | 1:31.499Jim Devenport · fastest of 16 · top 5 within 2.2s | 1:31.826Jeff Shafer · fastest of 26 · top 5 within 4.9s | 1:32.481Jeff Shafer · fastest of 24 · top 5 within 3.8s | +0.982squal +1.032s | 101.1%qual 101.1% | 1:58.306Chris Haldeman · fastest of 86 · top 5 within 0.5s | 1:59.100Michael Gagliardo · fastest of 83 · top 5 within 0.6s | +27.601squal +27.512s | 130.2%qual 130.3% | 1:44.601Zach Holden · fastest of 36 · top 5 within 1.2s | 1:44.524Jonathon Kotyk · fastest of 36 · top 5 within 0.5s | +13.025squal +13.807s | 114.2%qual 115.2% | ||||||
| No rule changes on record between these events | ||||||||||||||||||||
| Mid-Ohio Sports Car Course Runoffs 20162016-09-19 | 1:17.308James Devenport · fastest of 14 · top 5 within 2.7s | 1:19.407Gianpaolo Ciancimino · fastest of 13 · top 5 within 1.8s | 1:20.188Jeff Shafer · fastest of 18 · top 5 within 4.0s | 1:20.904Jeff Shafer · fastest of 16 · top 5 within 2.2s | +1.497squal +2.880s | 101.9%qual 103.7% | 1:40.514Justin Hille · fastest of 45 · top 5 within 0.3s | 1:40.764Michael Carter · fastest of 44 · top 5 within 0.3s | +21.357squal +23.206s | 126.9%qual 130.0% | 1:29.213Neil Verhagen · fastest of 14 · top 5 within 2.1s | 1:30.133Neil Verhagen · fastest of 14 · top 5 within 1.4s | +10.726squal +11.905s | 113.5%qual 115.4% | ||||||
| No rule changes on record between these events | ||||||||||||||||||||
| Daytona International Speedway Runoffs 20152015-09-21 | 1:49.219Jim Downing · fastest of 9 · top 5 within 2.2s | 1:49.792Gianpaolo Ciancimino · fastest of 10 · top 5 within 1.7s | 1:51.825Chris Farrell · fastest of 17 · top 5 within 3.6s | 1:52.355Jeff Shafer · fastest of 17 · top 5 within 2.8s | +2.563squal +2.606s | 102.3%qual 102.4% | 2:18.661Andrew Carbonell · fastest of 62 · top 5 within 0.6s | 2:24.067Todd Lamb · fastest of 59 · top 5 within 0.8s | +34.275squal +29.442s | 131.2%qual 127.0% | 2:02.489Tim Kautz · fastest of 25 · top 5 within 1.1s | 2:03.383Rick Payne · fastest of 22 · top 5 within 0.8s | +13.591squal +13.270s | 112.4%qual 112.1% | ||||||
By track
| Track | Events | Typical % of P1 | Best | Latest |
|---|---|---|---|---|
| Road America | 4 | 100.0%2 of 4 with P1 | 100.0%Runoffs 2020 | 100.0%Runoffs 2024 |
| 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 P1's best on the same day: the weather, the track and its configuration cancel out, so one figure compares across tracks and years where lap times cannot. 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.