BoP Lab / Classes / P2
P2 vs FE2 vs SM vs STL pace at every track
Lap times across years say as much about the weather as the class. % of P2 is each class's best lap as a share of P2'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: P2 100.0% of P2 Jeff Shafer, Daytona International Speedway Runoffs 2015 race · FE2 97.2% of P2 Jason Conzo, Virginia International Raceway Runoffs 2022 race · SM 102.4% of P2 Travis Wiley, Virginia International Raceway Runoffs 2022 race · STL 94.1% of P2 Danny Steyn, Virginia International Raceway Runoffs 2022 race
| Event | P2 | FE2 | SM | STL | ||||||||||||||||
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| Qual best | Race best | Trap | Qual best | Race best | Trap | vs P2 | % of P2 | Qual best | Race best | Trap | vs P2 | % of P2 | Qual best | Race best | Trap | vs P2 | % of P2 | |||
| 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%) | 2:12.326Franklin 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%) | +2.440squal +1.720s | 101.9%qual 101.3% | 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%) | +33.284squal +31.567s | 125.7%qual 124.2% | 2:30.537Derek Ketchie · fastest of 16 · top 5 within 2.9s-1.528s (-1.00%) | 2:30.657Danny Steyn · fastest of 16 · top 5 within 0.6s-1.470s (-0.97%) | 134.8Mike Taylor+2.6 mph (+2.0%) | +21.216squal +19.931s | 116.4%qual 115.3% | ||
7 rule changes (FE2: 1, SM: 2, STL: 4)3 cars added · 1 weight · 2 wording · 1 other · SM/SMX Mazda rear toe link part number revised from 0000-04-5361426 to 0000-04-5361. · STL removes Mazda MX-5 Cup entirely; renames Spec MX5 Challenge to Spec MX5; renames Global Cup to MX-5 Cup (16-18); removes Global Cup (2019). · STL, STU weight calculation procedure clarified: positive percentages added first, negative subtracted second, then fixed weights applied. · SM/SMX part number 0000-10-6900 replaced with 0000-06-5016-KT in GCR 9.1.7.C.1.j.1.c. · STL adds Mazda BP 1.6, 1600cc, minimum weight 2160 lbs. · STL minimum weights increase across all engine sizes, 1300cc to 1850cc up to 195–250 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 | 2:12.475Franklin 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%) | 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%) | 2:32.065Jose Osiris Pena · fastest of 14 · top 5 within 3.4s+2.002s (+1.33%) | 2:32.127Jose Osiris Pena · fastest of 13 · top 5 within 2.4s+1.882s (+1.25%) | 132.2Jon Sewell-2.1 mph (-1.5%) | |||||||||||
9 rule changes (P2: 1, FE2: 1, SM: 4, STL: 3)2 weight · 1 cars added · 4 wording · 2 other · Lotus Evora GT4 minimum weight drops to 2700 lbs; Elise Cup R to 2250 lbs; Elise SC and Exige SC to 2450–2550 lbs. · 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. · 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. · STL Mazda MX5 Challenge minimum weight now references GCR 9.1.7.1; mandatory component spec list removed, alternative tires only allowed. · FE2 allows pre-approved driver safety and comfort seat and control modifications for drivers with disabilities, per logbook. · 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. · STL STU Mazda Miata alternate front hubs Mazda Motorsports Development Part #0000-04-5HUB-S1 approved.show
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| Road America Runoffs 20242024-10-01 | 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%) | 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%) | +4.426squal +4.101s | 103.4%qual 103.2% | 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%) | +33.164squal +33.701s | 125.8%qual 126.5% | 2:30.063Joe Moser · fastest of 18 · top 5 within 3.7s-1.357s (-0.90%) | 2:30.245Joe Moser · fastest of 16 · top 5 within 4.2s-1.870s (-1.23%) | 134.3Joe Moser+1.3 mph (+1.0%) | +21.923squal +22.658s | 117.1%qual 117.8% | ||
13 rule changes (P2: 5, SM: 4, STL: 4)4 engine · 1 aero · 1 weight · 6 wording · 1 other · 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. · 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. · STL and STU now permit electric power steering pumps, OEM electric-assisted steering, or column-mounted electric steering assist systems. · STL normally aspirated minimum weights reduced: 1900cc to 2540 lbs, 1950cc to 2583 lbs, 2000cc to 2625 lbs; short-wheelbase FWD adds 1.25%; Honda B16/B17/B18C1 throttle to 51mm, B18C Type R and Mazda MZR to 50mm. · STL Mazda 12A: 5th and 6th intake port actuators and valves may no longer be removed or disabled. · 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. · STL 79-85 RX7 12A now allows auto-type 2 bbl carburetor with 42mm choke on dual-y manifold, not just stock Nikki. · 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 | 1:48.590Greg 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%) | 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%) | +2.269squal +2.075s | 102.1%qual 101.9% | 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%) | +27.400squal +26.396s | 125.2%qual 124.3% | 2:05.779Danny Steyn · fastest of 22 · top 5 within 3.4s+0.305s (+0.24%) | 2:06.682Joe Moser · fastest of 20 · top 5 within 1.5s-1.150s (-0.90%) | 131.8Danny Steyn+0.1 mph (+0.1%) | +17.853squal +17.189s | 116.4%qual 115.8% | ||
11 rule changes (P2: 8, SM: 1, STL: 2)2 cars added · 2 engine · 1 weight · 6 wording · STL ITA and ITS RX7, and ITS/ITA/ITB/ITC 1985+ models clarified to require tires per 9.1.4.2. · 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. · SM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore. · Spec MX5 in STL allows ACT clutch 0000-02-5004-G6, wheels 17x8, Toyo RR and RA1 235-40-17 tyres, or alternatives on 17x7 per rules.show
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| Virginia International Raceway Runoffs 20222022-09-24 | 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%) | 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%) | -3.789squal +3.287s | 97.2%qual 103.1% | 2:14.664Danny Steyn · fastest of 60 · top 5 within 0.2s+0.112s (+0.08%) | 2:19.107Travis Wiley · fastest of 58 · top 5 within 0.9s+2.648s (+1.94%) | 119.2Jonathan Neudorf-0.6 mph (-0.5%) | +3.273squal +27.098s | 102.4%qual 125.2% | 2:05.474Danny Steyn · fastest of 24 · top 5 within 2.3s-1.729s (-1.36%) | 2:07.832Danny Steyn · fastest of 22 · top 5 within 1.9s+0.559s (+0.44%) | 131.7Trever Degioanni-3.2 mph (-2.3%) | -8.002squal +17.908s | 94.1%qual 116.6% | ||
16 rule changes (P2: 10, SM: 1, STL: 5)2 weight · 1 cars added · 1 engine · 1 tyres & wheels · 10 wording · 1 other · 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. · STU single throttle body weight reduction removed; minimum weights revised down to 2990 lbs at 3000cc from 3300 lbs. · STL and STU Improved Touring vehicles must now conform to section 9.1.4 Tires & Wheels. · 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. · P2 Control Area definition clarified: rectangular zone from rear edge of front tires to front edge of rear tires, full car width. · STL/STU intake manifold and cylinder head porting clarified as free; intake and exhaust porting wording removed. · STL Mazda Renesis flat plate restrictor increases from 55mm to 60mm. · STL 79-85 RX7 12A allows emissions removal and jet correction on stock Nikki carb. · 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 | 1:33.235Tim 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 | 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 | +1.333squal +3.160s | 101.4%qual 103.4% | 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 | +23.515squal +24.460s | 124.7%qual 126.2% | 1:51.665Danny Steyn · fastest of 42 · top 5 within 1.7s-0.982s (-0.87%) | 2:02.711Joe Moser · fastest of 37 · top 5 within 3.2s+10.122s (+8.99%) | 131.8Max Gee | +27.389squal +18.430s | 128.7%qual 119.8% | ||
24 rule changes (P2: 8, SM: 1, STL: 15)5 engine · 3 cars added · 2 aero · 2 weight · 1 induction · 1 suspension & brakes · 8 wording · 2 other · P2 CN Honda K20A-FD2 engine rebuild clarified: balancing, porting, polishing prohibited; valve jobs and honing must follow factory procedures. · STL Mazda Spec MX-5 removes redundant specification line referencing 2014 regulations. · 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. · STL Volkswagen 2.0L TFSI 1984 cc engine permitted without turbocharger, meeting all other STL specs. · 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. · STL Pontiac Solstice/Saturn Sky allowed 4 inch ride height. · STL Mazda B5 DOHC added to class; must meet all STL regulations. · STL Honda B16A (JDM) restrictor reduced from 54mm to 53mm. · SM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture. · ST oil coolers and filters now explicitly listed as addable or substitutable parts in vents and breathers section. · P2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front, 14–15 rear wheel width. · STL GM Ecotec LNF now permits any Ecotec engine family with 55mm flat plate restrictor. · ST 90-05 Mazda Miata allowed alternate front wheel hub Mazda Motorsports Development Part #0000-04-5HUB-S1. · ST cars may now relocate ABS actuation hardware and wiring anywhere in the engine compartment. · STL rear wing trailing edge may be mounted no further rearward than the center of the rearmost part approved bodywork. · STL alternate transmissions now allow OEM gear sets and input shaft modifications for fitment. · STL RWD strut-front cars lose 2.5% weight penalty, others lose 3% penalty for FWD parity. · STL Honda F20C drops 2% weight penalty, minimum weight reduced. · STL Honda B16/B17/B18C1 restrictor reduced to 53mm, B18C variants and Mazda MZR to 52mm. · 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. · ST aero devices and reference areas must include end plates, exclude fasteners under 1/2" protrusion.show
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| Road America Runoffs 20202020-10-02 | 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 | 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 | +3.478squal +4.292s | 102.7%qual 103.3% | 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 | +33.955squal +33.695s | 126.2%qual 126.2% | 2:31.420Danny Steyn · fastest of 33 · top 5 within 3.1s | 2:32.115Joe Moser · fastest of 30 · top 5 within 1.5s | 132.9Darin Treakle | +22.322squal +22.906s | 117.2%qual 117.8% | ||
21 rule changes (P2: 6, FE2: 2, SM: 2, STL: 11)5 cars added · 5 engine · 1 aero · 1 induction · 1 suspension & brakes · 1 weight · 6 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. · 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. · SM rear brake caliper may use single bracket under upper retaining bolt head to prevent pin failure. · STL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis percentage additions, subtractions, and fixed pounds. · STL STU rear wing Gurney flap terminology clarified from wicker to Gurney flap in mounting and chord rules. · GT3 and STU add Borg-Warner EFR6258 turbocharger to approved turbo lists. · Elan NP01 added to P2 Table 1 as Spec Line car with 2000cc displacement and 42mm restrictor. · STL adds Mazda MX-5 Global Cup 16-18 at 2450 lbs minimum and 2019 at 2550 lbs minimum. · STL Mazda MX-5 Club 06-15 allowed header part number 0000-06-5407-NC. · STL Acura/Honda B18 and B18C engines: restrictor sizes swapped, B18C1 removed from allowed variants. · P2 Enterprises Sports Racer now permits 55mm flat plate intake restrictor Part # WM303013 as alternative to SIR. · STL Honda B18 loses 53mm restrictor requirement; B18C1 added with 54mm restrictor, B18C1 removed from other variants. · P2 Enterprise Sports Racer 2.3L engine must use SIR or Flat Plate restrictor meeting peak horsepower, sized in whole or 0.5mm increments. · STU GM Ecotech LNF now permitted without turbo, with LE5 head and intake manifold, meeting STL specs. · STL Mazda MZR restrictor reduced from 54 mm to 53 mm. · STL Mazda MZR restrictor reduces from 55 mm to 53 mm. · P2 electronic throttle control wording clarified: ETC permitted if stock ECU throttle pedal activates original throttle shaft mechanism. · STL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL to notes. · 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 | 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 | 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 | +1.896squal +1.951s | 101.7%qual 101.8% | 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 | +26.201squal +25.441s | 123.8%qual 123.3% | 2:07.203Danny Steyn · fastest of 36 · top 5 within 1.8s | 2:07.273Cliff Ira · fastest of 35 · top 5 within 1.4s | 134.8Cliff Ira | +17.015squal +18.092s | 115.4%qual 116.6% | ||
24 rule changes (P2: 9, SM: 4, STL: 11)7 engine · 4 cars added · 2 weight · 1 induction · 6 wording · 4 other · P2 Honda K20A-FD2 non-composite chassis intake restrictor note clarified; restrictor implementation date removed. · STL adds Mazda Spec MX-5 Challenge, 2000cc displacement, 2500 lb minimum weight, with mandatory Roush, Penske, Eibach, and other specified components. · 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. · P2 cars limited to power application on maximum two wheels. · STU allows alternate intake manifolds on case-by-case basis; stock throttle device and manifold otherwise required. · P2 Enterprise minimum weight increased to 1375 lbs.; peak horsepower of sealed ESR engine reduced per CRB specification. · STL Acura/Honda B18 except C engine restrictor increased from 53mm to 54mm flat plate. · STL and STU ride height measurement clarified: lowest rocker panel point without driver, excluding pinch weld. · 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. · STL adds VW 1.8L R4 20VT 1781 cc, 1781 minimum weight, naturally aspirated only. · STL Mazda Renesis minimum weight reduced to 2700 lbs. · STL Mazda MX-5 Cup brake pad compound now open. · STL adds Acura/Honda B18C1 GSR with 1797cc displacement, 54mm flat plate restrictor required, porting outside 1" allowance prohibited. · STL Mazda 12 and 13B now permit port matching; porting ban removed. · 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. · 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. · STL B17 now requires 54mm flat plate restrictor; B18C Type R variants move to 54mm restrictor, weight chart baseline. · STL Mazda Miata removes maximum displacement limit; minimum weight corrected to unspecified figure.show
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| Sonoma Raceway Runoffs 20182018-10-10 | 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 | 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 | +3.492squal +6.256s | 103.8%qual 107.0% | 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 | +23.207squal +25.571s | 125.2%qual 128.8% | 1:49.138Danny Steyn · fastest of 19 · top 5 within 2.5s | 1:49.754Danny Steyn · fastest of 17 · top 5 within 2.5s | 103.2Craig McHaffie | +17.683squal +20.354s | 119.2%qual 122.9% | ||
| No rule changes on record between these events | ||||||||||||||||||||
| Indianapolis Motor Speedway Runoffs 20172017-09-25 | 1:31.826Jeff Shafer · fastest of 26 · top 5 within 4.9s | 1:32.481Jeff Shafer · fastest of 24 · top 5 within 3.8s | 1:58.306Chris Haldeman · fastest of 86 · top 5 within 0.5s | 1:59.100Michael Gagliardo · fastest of 83 · top 5 within 0.6s | +26.619squal +26.480s | 128.8%qual 128.8% | 1:52.647Adam Roberts · fastest of 57 · top 5 within 0.8s | 1:52.589Eric Kutil · fastest of 50 · top 5 within 1.2s | +20.108squal +20.821s | 121.7%qual 122.7% | ||||||||||
| No rule changes on record between these events | ||||||||||||||||||||
| Mid-Ohio Sports Car Course Runoffs 20162016-09-19 | 1:20.188Jeff Shafer · fastest of 18 · top 5 within 4.0s | 1:20.904Jeff Shafer · fastest of 16 · top 5 within 2.2s | 1:40.514Justin Hille · fastest of 45 · top 5 within 0.3s | 1:40.764Michael Carter · fastest of 44 · top 5 within 0.3s | +19.860squal +20.326s | 124.5%qual 125.3% | 1:35.439John Schmitt · fastest of 34 · top 5 within 1.5s | 1:36.625Kevin Boehm · fastest of 31 · top 5 within 0.6s | +15.721squal +15.251s | 119.4%qual 119.0% | ||||||||||
| No rule changes on record between these events | ||||||||||||||||||||
| Daytona International Speedway Runoffs 20152015-09-21 | 1:51.825Chris Farrell · fastest of 17 · top 5 within 3.6s | 1:52.355Jeff Shafer · fastest of 17 · top 5 within 2.8s | 2:18.661Andrew Carbonell · fastest of 62 · top 5 within 0.6s | 2:24.067Todd Lamb · fastest of 59 · top 5 within 0.8s | +31.712squal +26.836s | 128.2%qual 124.0% | 2:09.672Kevin Boehm · fastest of 37 · top 5 within 2.5s | 2:10.269Kevin Boehm · fastest of 37 · top 5 within 2.1s | +17.914squal +17.847s | 115.9%qual 116.0% | ||||||||||
By track
| Track | Events | Typical % of P2 | Best | Latest |
|---|---|---|---|---|
| Road America | 4 | 100.0%3 of 4 with P2 | 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 P2'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.