BoP Lab / Classes / P2

P2 vs F5 vs SM 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.

Class · click a class to switch, + to compare alongside (up to 4)

AS +B-Spec +EP +vsF5 ×FA +FC +FE2 +FF +FP +FV +FX +GT1 +GT2 +GTX +HP +P +P2×vsSM ×SMX +SRF3 +STL +STU +T1 +T2 +T3 +T4 +Show 50 inactive classes

Series Runoffs Super Tour Both

Reference class · the yardstick the % column and chart are 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

Quickest here: P2 1:20.188 Jeff Shafer, Runoffs 2016 qualifying · F5 1:28.528 Calvin Stewart, Runoffs 2016 qualifying · SM 1:40.514 Justin Hille, Runoffs 2016 qualifying

% of P2Lap times

P2F5SMsolid race · dashed qualifying · slower is lower

P2F5SMsolid race · dashed qualifying · each class's best lap as a share of P2's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker

	Event	P2			F5					SM
	Event	Qual best	Race best	Trap	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%)						2:42.173Brett 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 rule changes (SM: 2)1 wording · 1 other · 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.showhide 2026-07-01 SM Rear Toe Link #40271wordingwordingSM/SMX Mazda rear toe link part number revised from 0000-04-5361426 to 0000-04-5361. 2026-04-01 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.
	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%)
5 rule changes (P2: 1, SM: 4)1 weight · 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. · 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. · 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.showhide 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 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. 2024-12-01 P2 2000 cc Pinto Engine Car Weight #37187weightslower · weightP2 2000 cc Pinto engine car minimum weight set to 1335 lbs. 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.
	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%)						2:41.106Ethan 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%
9 rule changes (P2: 5, SM: 4)2 engine · 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. · 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.showhide 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 #36556engineadded · engineSM 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. 2024-05-01 P2 CN Spec ECU #35835wordingwordingP2 Spec Line E engine notes clarify oil system, ECU, and exhaust remain unrestricted; wording only. 2024-05-01 P2 E&O - Correct FIA Group CN spec line notes #35900wordingwordingP2 FIA Group CN notes clarify V de V European Proto Endurance Challenge bodywork, rear diffuser, wing, wheels, assisted shifting allowed; regulations link provided. 2024-01-01 P2 E&O - Clarify B.1 modified engine range in AMAC spec lines #35225wordingwordingP2 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. 2024-01-01 P2 Replacement Engine Crankcase for 07/08 Suzuki GSX-R1000 Engines #35340engineadded · engineP2 Suzuki GSX-R1000 engine: 2007–2008 crankcase 11300-21860 may be replaced with 2016–2019 GSX-S1000 part 11301-04840. 2023-12-01 P2 Correct Table 1 for Engine Date Range Specifications #35182wordingwordingP2 Table 1 engine date ranges clarified: Stock Engine replaced with specific marques Suzuki, Yamaha, Honda, BMW for 2009-newer and 2008-older rows.
	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%)						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%
9 rule changes (P2: 8, SM: 1)2 engine · 1 cars added · 1 weight · 5 wording · 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.showhide 2023-05-01 P2 Clarify minimum side body height requirement #34143wordingwordingP2 minimum side body height must equal front axle centerline height, viewed from side. 2023-05-01 P2 Clarify closed cockpit single seat car allowance #34144wordingwordingP2 closed cockpit single seat cars now prohibited unless Table 1 spec line permits. 2023-04-01 P2 Remove redundant effective date language and update engine table #34012wordingwordingP2 engine table spec line B.1 redundant effective date language removed and table updated. 2023-04-01 P2 E&O - Correct dimensional equivalents #34038enginefaster · engineP2 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. 2023-01-01 P2 Request to Classify Sebeco NP01 #33378cars addedaddedSebeco NP01-EVO and Elan NP01 added to P2 with Mazda 2.0L MZR, no restrictor required, 1600 lb minimum weight. 2023-01-01 P2 Radical spec line clarifications #33485wordingwordingP2 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. 2023-01-01 P2 E&O original class intent #33519wordingwordingP2 chassis now allows composite materials partially installed; anti-intrusion panels attachment simplified; Stohr and converted models clarified. 2023-01-01 P2 Update Engine Table Spec Line B.1 #33608engine 2023-01-01 SM BOP for NB1 and NB2 #32309weightslower · weightSM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore.
	Virginia International Raceway Runoffs 20222022-09-24	1:47.566Tim 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%)	1:57.689James Weida · fastest of 11 · top 5 within 3.9s+0.328s (+0.28%)	2:21.862Sven de Vries · fastest of 10 · top 5 within 14.3s+24.290s (+20.66%)	142.9Calvin Stewart+0.1 mph (+0.1%)	+6.028squal +10.123s	104.4%qual 109.4%	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%)	+3.273squal +27.098s	102.4%qual 125.2%
17 rule changes (P2: 10, F5: 6, SM: 1)1 cars added · 1 engine · 1 weight · 11 wording · 3 other · F500 Rotax 493 and 593 intake boots: removed Moto Tassinari V3124-873B-2 from 493/593 non-HO allowance, added Moto Tassinari V3120-794A-2 option for non-HO. · F500 Rotax engines now permit Ingi Tech Sparker ignition DCP-CDI-P2 as alternate ECU. · F500 clarifies stepped diameter exhaust headers prohibited except at cylinder head flange area. · F500 Rotax 593 intake boot options clarified; oil injection pump removal now permitted. · 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. · F500 Majors and Runoffs cars must install AIM part #X47KPFSOLO2R0 data box mount for Solo or Solo 2. · 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. · F5 cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs. · 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.showhide 2022-09-01 F5 Intake Boots Correction #33028wordingwordingF500 Rotax 493 and 593 intake boots: removed Moto Tassinari V3124-873B-2 from 493/593 non-HO allowance, added Moto Tassinari V3120-794A-2 option for non-HO. 2022-08-01 F5 Ensure availability of ECU for Rotax engines #32695engineadded · engineF500 Rotax engines now permit Ingi Tech Sparker ignition DCP-CDI-P2 as alternate ECU. 2022-07-01 F5 Clarify stepped exhaust header references #32743wordingwordingF500 clarifies stepped diameter exhaust headers prohibited except at cylinder head flange area. 2022-06-01 F5 593 carb boot availability and oil pump clarification #32527wordingwordingF500 Rotax 593 intake boot options clarified; oil injection pump removal now permitted. 2022-05-01 P2 E&O Clarification of Chassis Construction Requirements #32469wordingwordingP2 chassis construction clarified: full composite allowed; partial composite must roll without composite parts installed. 2022-05-01 P2 Clean up P2 wording #32525wordingwordingP2 classification wording cleaned up in GCR section 9.1.8.C and GCR contents. 2022-04-01 P2 After Market to Aftermarket #32373wordingwordingP2 Oldsmobile cam rules correct spelling from 'after market' to 'aftermarket' in two sections. 2022-04-01 SM Update GCR Section 9.1.7.3.A.1. #32217wordingwordingSM Majors must run authorized Penske shock and mount; Regional competitors not required until further evaluation. 2022-03-01 F5 E&O class name #32194otheraddedF500 Majors and Runoffs cars must install AIM part #X47KPFSOLO2R0 data box mount for Solo or Solo 2. 2022-03-01 P2 Add spec line for Beasley B2 #32147cars addedaddedP2 adds Beasley B2 at 1350 lbs with Mazda 12A, 40.5mm venturi, and up to 16.5in wing chord. 2022-03-01 P2 E&O Table 1 spec line wing terminology #32148wordingwordingP2 wings: terminology change from 'cord' to 'chord', and 'only' removed from Bobsy and Jondal notes. 2022-03-01 P2 E&O class name #32196wordingwordingP2 Converted F5 cars renamed F500, must retain F500 suspension, minimum width 55 inches. 2022-02-01 P2 E&O Engine section #31969weightslower · weightP2 motorcycle engines gain 5cc to 1505cc max, two-stroke gains 5cc to 1205cc max, automotive engines add 50 lbs minimum weight to 1350 lbs. 2022-01-01 F5 Data Box Mounting Plate #31638otheraddedF5 cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs. 2022-01-01 P2 E&O letter #31539 – Control Area definition #31783wordingwordingP2 Control Area definition clarified: rectangular zone from rear edge of front tires to front edge of rear tires, full car width. 2021-12-01 P2 BoP adjustment effective 1-1-22 #31538otherunclearP2 specification line B.1 engine table entry amended; details of change not provided in excerpt. 2021-12-01 P2 E&O clarification of "Control Area" definition #31539wordingwordingP2 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.
	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	1:42.619Ryan Mayfield · fastest of 22 · top 5 within 1.6s-0.517s (-0.50%)	1:43.140Sven de Vries · fastest of 20 · top 5 within 1.7s+0.280s (+0.27%)	144.4James Weida	+7.818squal +9.384s	108.2%qual 110.1%	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%
12 rule changes (P2: 8, F5: 3, SM: 1)2 cars added · 2 engine · 8 wording · P2 CN Honda K20A-FD2 engine rebuild clarified: balancing, porting, polishing prohibited; valve jobs and honing must follow factory procedures. · F5 clarifies mechanical shifting only; throttle-cut and flat-shifter devices permitted if driver retains full control. · F5 single-seat open-wheel cars: rigid suspension becomes limited suspension in class definition. · 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. · F500 Rotax 593 HO engine now permitted; 875 lbs minimum weight, MA0242SP1020A or MA0242SP1063A restrictor, specific intake boots and piston required. · 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. · SM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture. · P2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front, 14–15 rear wheel width. · 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.showhide 2021-09-01 P2 P2 CN Engine Rebuild Clarification #31000wordingwordingP2 CN Honda K20A-FD2 engine rebuild clarified: balancing, porting, polishing prohibited; valve jobs and honing must follow factory procedures. 2021-08-01 F5 Clarify allowable assisted shifting systems #30871wordingwordingF5 clarifies mechanical shifting only; throttle-cut and flat-shifter devices permitted if driver retains full control. 2021-08-01 F5 Request to correct terminology #30976wordingwordingF5 single-seat open-wheel cars: rigid suspension becomes limited suspension in class definition. 2021-08-01 P2 F5 P2 Conversion #30856wordingwordingP2 Converted F5 cars must retain F5 suspension and meet P2 non-spec requirements except minimum width is 55 inches. 2021-08-01 P2 Clarify minimum body width requirement #30859wordingwordingP2 minimum body width clarified: cannot extend inward beyond vertical plane through tire centerlines. 2021-06-01 F5 Request to Allow Rotax 593 HO Engine #30712cars addedaddedF500 Rotax 593 HO engine now permitted; 875 lbs minimum weight, MA0242SP1020A or MA0242SP1063A restrictor, specific intake boots and piston required. 2021-05-01 P2 E&O tonneau cover provision in cockpit opening section #30459wordingwordingP2 tonneau covers now allowed to meet minimum dimensions; cockpit equipment attachment wording clarified. 2021-05-01 P2 Remove effective dates in Table 1 #30468wordingwordingP2 removes effective date 01/01/2021 from six car spec lines in Table 1. 2021-05-01 P2 E&O Maximum Valves Per Cylinder #30560engineengineP2 engine specs B.1, B.2, B.3 limited to maximum 4 valves per cylinder. 2021-04-01 SM Updates - Obsolete Parts & BOP Parts #30438wordingaddedSM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture. 2021-03-01 P2 Add a new spec line for a 2-cycle, 3-cylinder engine up to 820cc #30272cars addedaddedP2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front, 14–15 rear wheel width. 2020-12-01 P2 Balance of Performance adjustments effective 01-01-2021 #29822engineunclearP2 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.
	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	2:20.954Calvin Stewart · fastest of 16 · top 5 within 1.8s	2:21.391James Weida · fastest of 14 · top 5 within 1.5s	143.2Aaron Ellis	+11.598squal +12.440s	108.9%qual 109.7%	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%
14 rule changes (P2: 6, F5: 6, SM: 2)3 engine · 2 induction · 1 aero · 1 cars added · 1 suspension & brakes · 5 wording · 1 other · F500 Suzuki GSXR600 engine years extended from 2003-2013 to 2003-2019. · 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. · SM rear brake caliper may use single bracket under upper retaining bolt head to prevent pin failure. · F5 request to adjust external jetting device cockpit control denied; no rule change made. · F5 driver adjustable carburettor mixture: refer to separate Fastrack letter #28359 for ruling. · F5 cockpit adjustment request response published in Fastrack letter 28359. · 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. · F500 Honda CBR600RR, Suzuki GSXR600, Yamaha R6 restrictor reduced to 28mm from 29mm. · P2 adds BMW to permitted motorcycle-based engines alongside Kawasaki, Suzuki, Yamaha, Honda.showhide 2020-10-01 F5 Request to Update Suzuki Engine Years for F500 #29453engineadded · engineF500 Suzuki GSXR600 engine years extended from 2003-2013 to 2003-2019. 2020-10-01 SM Radiator E&O Clarifications #29294wordingwordingSM allows aftermarket radiators in original location with stock OEM cooling fan, and permits 1990-1997 cars to install upper radiator seal NA75-50-OK7A. 2020-09-01 P2 E&O clarification of P2 rear wing requirements #29205aeroaeroP2 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. 2020-08-01 SM Modifications to prevent failures of Rear Brake Caliper Pin #28953suspension & brakessuspension & brakesSM rear brake caliper may use single bracket under upper retaining bolt head to prevent pin failure. 2020-07-01 F5 Request for Cockpit Adjustment of External Jetting Devices #28359wordingunclearF5 request to adjust external jetting device cockpit control denied; no rule change made. 2020-07-01 F5 Two Stroke Motors (reply to #28359 WDYT) #28816engine 2020-07-01 F5 Re letter requesting driver adjustable carb mixture #28840wordingunclearF5 driver adjustable carburettor mixture: refer to separate Fastrack letter #28359 for ruling. 2020-07-01 F5 #28359 WDYT Request for Cockpit Adjustment #28875wordingunclearF5 cockpit adjustment request response published in Fastrack letter 28359. 2020-06-01 P2 Classify Elan NP01 in P2 Table 1 #28812cars addedaddedElan NP01 added to P2 Table 1 as Spec Line car with 2000cc displacement and 42mm restrictor. 2020-05-01 P2 SCCA Enterprises ESR / P2 engine restrictor testing #28669otheraddedP2 Enterprises Sports Racer now permits 55mm flat plate intake restrictor Part # WM303013 as alternative to SIR. 2020-04-01 P2 Add ESR inlet restrictor #27869inductionadded · inductionP2 Enterprise Sports Racer 2.3L engine must use SIR or Flat Plate restrictor meeting peak horsepower, sized in whole or 0.5mm increments. 2020-03-01 P2 Request for Fly by Wire Rule Wording Change #28247wordingwordingP2 electronic throttle control wording clarified: ETC permitted if stock ECU throttle pedal activates original throttle shaft mechanism. 2020-01-01 F5 Change 600cc restrictor size #27883inductionslower · inductionF500 Honda CBR600RR, Suzuki GSXR600, Yamaha R6 restrictor reduced to 28mm from 29mm. 2020-01-01 P2 Request for addition of BMW Engine in P2 Engine Table #27821engineadded · engineP2 adds BMW to permitted motorcycle-based engines alongside Kawasaki, Suzuki, Yamaha, Honda.
	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	1:57.361Wiley Mcmahan · fastest of 15 · top 5 within 3.8s	1:57.572Wiley Mcmahan · fastest of 15 · top 5 within 4.0s	142.8Eric McRee	+7.314squal +8.250s	106.6%qual 107.6%	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	+26.201squal +25.441s	123.8%qual 123.3%
14 rule changes (P2: 9, F5: 1, SM: 4)4 engine · 2 weight · 1 cars added · 1 induction · 4 wording · 2 other · P2 Honda K20A-FD2 non-composite chassis intake restrictor note clarified; restrictor implementation date removed. · F500 Honda CBR600RR, Suzuki GSXR600, and Yamaha R6 minimum weights increase to 900 lbs. · 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. · P2 Enterprise minimum weight increased to 1375 lbs.; peak horsepower of sealed ESR engine reduced per CRB specification. · 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. · 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.showhide 2019-10-01 P2 Update Engine Table Line E notes #27414wordingwordingP2 Honda K20A-FD2 non-composite chassis intake restrictor note clarified; restrictor implementation date removed. 2019-08-31 F5 Request for Weight Increase for Motorcycle Powered Cars #27214weight +25 lbsslower · weightF500 Honda CBR600RR, Suzuki GSXR600, and Yamaha R6 minimum weights increase to 900 lbs. 2019-08-31 P2 Update P2 Engine Table spec lines to reflect 3/1/2019 #27254engineslower · engineP2 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. 2019-07-01 P2 E&O Transmissions #27006engineslower · engineP2 cars limited to power application on maximum two wheels. 2019-06-01 P2 Request to restrict all cars #26246weightslower · weightP2 Enterprise minimum weight increased to 1375 lbs.; peak horsepower of sealed ESR engine reduced per CRB specification. 2019-03-01 P2 Change Engine Table Lines B.1 & B.5 #25777inductionslower · inductionP2 stock and modified engines get smaller restrictors (35.0mm, 34.0mm, 33.0mm) and heavier minimums (1025, 1125, 1185 lbs). 2019-03-01 P2 Change Line A.1 restrictor size #26429engineslower · engineP2 Line A.1 restrictor reduced from 40mm to 38mm. 2019-03-01 SM Request to allow aftermarket fuel filters. #26370otheraddedSM fuel pump and filter now permitted as Mazda or OEM equivalent part. 2019-02-01 SM Request 99-00 replacement Wire harnesses #25602otheraddedSM allows factory Mazda ECU and injector harnesses (P/N 0000-10-020E-99, 0000-10-080D-99) on 1999–2000 model year cars, unmodified. 2019-02-01 SM Organize and Clarify 9.1.7.C.1.o. #25913wordingwordingSM electrical rules reorganized and clarified; alternator now externally regulated only by OEM ECU or master kill switch; harness repair by splicing permitted. 2019-02-01 SM Strike Tire Tread Language #26123wordingremovedSM tire tread protrusion language removed from GCR 9.1.7.C.5. 2019-01-01 P2 Request to Allow 1345cc Hayabusa Engines for Spec Line P2 Cars #25595cars addedaddedP2 Spec Line cars now allow 1345cc Hayabusa stock engines at 1050 lb minimum with 30mm restrictor. 2019-01-01 P2 Change CN inlet restrictor implementation date #25816wordingwordingP2 Group CN Honda K20A-FD2 55mm intake restrictor implementation delayed from 1 January to 3 March 2019. 2019-01-01 P2 Clarify Honda K20A-FD2 parts requirement #25950engineslower · engineP2 Honda K20A-FD2 Group CN must use stock intake manifold, 64mm throttle, 55mm restrictor at 1500 lbs minimum.
	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	1:41.807Jeff Jorgenson · fastest of 5 · top 5 within 6.6s	1:42.491David Lapham · fastest of 5 · top 5 within 9.5s	113.3David Lapham	+10.420squal +13.023s	111.3%qual 114.7%	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%
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		1:43.136Wiley Clinton McMahan · fastest of 38 · top 5 within 1.4s	1:42.860Wiley Clinton McMahan · fastest of 37 · top 5 within 1.6s		+10.379squal +11.310s	111.2%qual 112.3%	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%
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		1:28.528Calvin Stewart · fastest of 14 · top 5 within 3.9s	1:29.853Steven Thompson · fastest of 12 · top 5 within 4.5s		+8.949squal +8.340s	111.1%qual 110.4%	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%
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		2:01.824W. Clint McMahan · fastest of 16 · top 5 within 3.0s	2:03.298Matthew Strand · fastest of 15 · top 5 within 4.9s		+10.943squal +9.999s	109.7%qual 108.9%	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%

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, 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.