BoP Lab / Classes / SM

SM vs P pace at every track

Lap times across years say as much about the weather as the class. % of SM is each class's best lap as a share of SM'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 +FA +FC +FE2 +FF +FP +FV +FX +GT1 +GT2 +GTX +HP +vsP ×P2 +SM×SMX +SRF3 +STL +STU +T1 +T2 +T3 +T4 +Show 51 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: SM 1:40.514 Justin Hille, Runoffs 2016 qualifying · P 2:01.180 Lee Alexander, Runoffs 2025 qualifying

% of SMLap times

SMPsolid race · dashed qualifying · slower is lower

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

	Event	SM			P
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs SM	% of SM
	Road America Runoffs 20262026-09-28	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%)	2:02.281Perry Richardson · fastest of 10 · top 5 within 1.3s+1.101s (+0.91%)	2:03.283Lawrence Loshak · fastest of 10 · top 5 within 0.8s+1.161s (+0.95%)	165.6Jason Miller+0.7 mph (+0.4%)	-39.442squal -39.892s	75.8%qual 75.4%
3 rule changes (SM: 2, P: 1)1 wording · 2 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. · Prototype carbon-carbon and carbon-ceramic brake rotors permitted; rotor material now unrestricted.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. 2026-01-01 P Request to Continue to Allow Carbon Brakes #39476otheraddedPrototype carbon-carbon and carbon-ceramic brake rotors permitted; rotor material now unrestricted.
	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%)	2:01.180Lee Alexander · fastest of 14 · top 5 within 1.5s	2:02.122Bart Wolf · fastest of 13 · top 5 within 2.1s	165.0Jason Miller	-42.308squal -41.931s	74.3%qual 74.3%
11 rule changes (SM: 4, P: 7)2 cars added · 2 engine · 6 wording · 1 other · Prototype 13B rotary restrictor changes to 40mm SIR fuel injection or 41.5mm venturi carburetor. · Prototype class adds Radical SR3 to Table 1 Spec Line Cars. · Prototype P2 cars may now run P2 specification or modify to Prototype rules in Prototype class; Radical Cup series added as spec line car. · Prototype Engine Table A 2-cycle restrictor reduced from 40mm to 38mm venturi size. · 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. · Class P adds engine and car notes: Line D no restrictor at 1150 lbs; Line G CN Honda K20A-FD2 unrestricted ITBs at 1500 lbs; Beasley B2 Mazda 12A 40.5mm venturi; P2 2000cc auto rules clarified. · 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. · Prototype Spec Lines B and D: wording corrections to engine table notes; no performance change. · Prototype class renamed from P1 to P, with P1 and P2 designations removed throughout GCR sections 9.1, 9.2.2, 9.3.37, and appendices. · 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 2025-09-01 P 13B Rotary Engine Rules Change Request #38856engineunclearPrototype 13B rotary restrictor changes to 40mm SIR fuel injection or 41.5mm venturi carburetor. 2025-09-01 P Add Radical Cup series Radical SR3 spec line to Table 1 #38916cars addedaddedPrototype class adds Radical SR3 to Table 1 Spec Line Cars. 2025-09-01 P Clarify spec line cars language #38943cars addedaddedPrototype P2 cars may now run P2 specification or modify to Prototype rules in Prototype class; Radical Cup series added as spec line car. 2025-08-01 P RM 25-05 - Prototype Engine Table A, 2 Cycle Restrictor Change #38929engineslowerenginePrototype Engine Table A 2-cycle restrictor reduced from 40mm to 38mm venturi size. 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 P Add missing punctuation marks #38150wordingaddedClass P adds engine and car notes: Line D no restrictor at 1150 lbs; Line G CN Honda K20A-FD2 unrestricted ITBs at 1500 lbs; Beasley B2 Mazda 12A 40.5mm venturi; P2 2000cc auto rules clarified. 2025-05-01 SM Clarify Tire Marking Regs #38005wordingwordingSM tire marking rules clarified: one Hoosier SM 7.5 P205/50/ZR17 set per Super Tour weekend, impound after first dry session, damaged tires may be replaced with used tires only. 2025-02-01 P Correct text in engine table notes #37606wordingwordingPrototype Spec Lines B and D: wording corrections to engine table notes; no performance change. 2025-02-01 P Update Prototype class designation #37653wordingwordingPrototype class renamed from P1 to P, with P1 and P2 designations removed throughout GCR sections 9.1, 9.2.2, 9.3.37, and appendices. 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	2:41.106Ethan 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%)
4 rule changes (SM: 4)1 engine · 2 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.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 #36556engineaddedengineSM and SMX must run latest AIM Data Logger Spec MX-5 ECU Protocol, effective 2024-09-01. 2024-09-01 SM Committee) OE versus OEM Definitons #36608wordingwordingSMX Mazda MX-5 OE versus OEM definitions clarified in GCR section 9.1.7.1; wording change only. 2024-09-01 SM Committee) Shifter Bushing #36611otheraddedSM and SMX now allow an alternate shifter bushing at the bottom of the shift lever.
	Virginia International Raceway Runoffs 20232023-09-23	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%)
1 rule change (SM: 1)1 weight · SM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore.showhide 2023-01-01 SM BOP for NB1 and NB2 #32309weightslowerweightSM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore.
	Virginia International Raceway Runoffs 20222022-09-24	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%)
1 rule change (SM: 1)1 wording · SM Majors must run authorized Penske shock and mount; Regional competitors not required until further evaluation.showhide 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.
	Indianapolis Motor Speedway Runoffs 20212021-09-25	1:57.695Brian Henderson · fastest of 90 · top 5 within 0.5s-0.611s (-0.52%)	1:58.837Brian Henderson · fastest of 88 · top 5 within 0.3s-0.263s (-0.22%)	119.8Kyle Greenhill
1 rule change (SM: 1)1 wording · SM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture.showhide 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.
	Road America Runoffs 20202020-10-02	2:42.209Kyle Greenhill · fastest of 77 · top 5 within 0.5s	2:43.748Preston Pardus · fastest of 75 · top 5 within 1.0s	121.3Kyle Greenhill
2 rule changes (SM: 2)1 suspension & brakes · 1 wording · 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. · SM rear brake caliper may use single bracket under upper retaining bolt head to prevent pin failure.showhide 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. 2020-08-01 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.
	Virginia International Raceway Runoffs 20192019-10-05	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
4 rule changes (SM: 4)2 wording · 2 other · 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.showhide 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.
	Sonoma Raceway Runoffs 20182018-10-10	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
No rule changes on record between these events
	Indianapolis Motor Speedway Runoffs 20172017-09-25	1:58.306Chris Haldeman · fastest of 86 · top 5 within 0.5s	1:59.100Michael Gagliardo · fastest of 83 · top 5 within 0.6s
No rule changes on record between these events
	Mid-Ohio Sports Car Course Runoffs 20162016-09-19	1:40.514Justin Hille · fastest of 45 · top 5 within 0.3s	1:40.764Michael Carter · fastest of 44 · top 5 within 0.3s
No rule changes on record between these events
	Daytona International Speedway Runoffs 20152015-09-21	2:18.661Andrew Carbonell · fastest of 62 · top 5 within 0.6s	2:24.067Todd Lamb · fastest of 59 · top 5 within 0.8s

By track

Track	Events	Typical % of SM	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 SM'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.