BoP Lab / Classes / STL

STL vs F5 vs P2 vs FP pace at every track

Lap times across years say as much about the weather as the class. % of STL is each class's best lap as a share of STL'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: remove one to add another)

ASB-SpecEPvsF5 ×FAFCFE2FFvsFP ×FVFXGT1GT2GTXHPPvsP2 ×SMSMXSRF3STL×STUT1T2T3T4Show 50 inactive classes

Series Runoffs Super Tour Both

Reference · what % is 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

Closest to the field: STL 100.0% of STL Kevin Boehm, Daytona International Speedway Runoffs 2015 race · F5 84.1% of STL Sven de Vries, Indianapolis Motor Speedway Runoffs 2021 race · P2 77.7% of STL Tim Day Jr, Indianapolis Motor Speedway Runoffs 2021 race · FP 97.7% of STL Cliff Ira, Indianapolis Motor Speedway Runoffs 2021 race

% of STLLap times

STLF5P2FPsolid race · dashed qualifying · slower is lower

STLF5P2FPsolid race · dashed qualifying · each class's best lap as a share of STL's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker

	Event	STL			F5					P2					FP
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs STL	% of STL	Qual best	Race best	Trap	vs STL	% of STL	Qual best	Race best	Trap	vs STL	% of STL
	Road America Runoffs 20262026-09-28	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%)						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%)	-21.216squal -19.931s	85.9%qual 86.8%	2:33.275Stephen Simonds · fastest of 26 · top 5 within 1.0s+0.880s (+0.58%)	2:33.240David Strittmatter · fastest of 25 · top 5 within 1.7s-1.031s (-0.67%)	132.4David Strittmatter±0.0 mph (±0.0%)	+2.583squal +2.738s	101.7%qual 101.8%
38 rule changes (STL: 4, FP: 34)13 weight · 9 engine · 7 induction · 2 cars added · 1 removed · 1 suspension & brakes · 1 tyres & wheels · 4 wordingshowhide 2026-08-01 FP Mini Cooper Compression Ratio #40517engine 2026-07-01 FP 1996-2000 Honda Civic (CX, DX, VP, LX) with Engine Code D16Y7 #40322engine 2026-07-01 FP 1275 Midget/Sprit Alternate intake manifold E/O #40370induction 2026-07-01 FP HP Honda Civic (92-95) #40464weight -70 lbs 2026-07-01 STL Spec Line Clean Up #40344removed 2026-06-01 STL Calculating Weight #40224weight 2026-05-01 FP Miata track width - errors and omissions #39976wording 2026-05-01 FP GCR Spec Line Correction #39977induction 2026-05-01 FP CGR Spec Line Weight Correction #39978weight 2026-05-01 FP Triumph GT6 Spec Change. #40098induction 2026-05-01 FP Request to Classify BMW E21 320i #40110cars added 2026-05-01 FP BMW 318is 84-85 engine displacement correction #40116engine 2026-04-01 STL Classifications #39885weight 2026-03-01 FP Correct Valve Sizes on FP Fiat x19 1300 and 1500 #39850engine 2026-03-01 FP Dual Carburetor Adjustments #39851induction 2026-02-01 FP Request Toyota 5E Series Engines #38208engine 2026-02-01 FP Request for Toyota 4E Series Engines #38209engine 2026-02-01 FP Dual Carbs for the Fiat X1/9 #39593induction 2026-01-01 STL Weight adjustment for STL #39579weight 2025-12-01 FP TR2 Notes E&O #39180weight 2025-12-01 FP Balance of Power #39187weight +50 lbs 2025-12-01 FP Competition Adjustment Request #39259weight -80 lbs 2025-12-01 FP Factory Roll Bar Removal on VW Convertible #39268wording 2025-12-01 FP FP Parity Request #39325weight +50 lbs 2025-12-01 FP Adjust former-GTL Honda's with B/D-Series Engines #39374engine 2025-11-01 FP Please Lower Weight of 280Z #38871weight -160 lbs 2025-11-01 FP Miata Weight Adjustment Follow Up #38949weight -25 lbs 2025-11-01 FP Weight Break for 1098 Midget / Sprite #38970weight -80 lbs 2025-11-01 FP HP Volvo 142 spec omission #38994engine 2025-11-01 FP HP Mini DOHC 1.6 #38996engine 2025-11-01 FP 83-88 FP Scirocco Spec Line Creation #38997cars added 2025-11-01 FP Add to Rabbit description #39019wording 2025-11-01 FP Clean-up 9.1.5.E.7e #39025suspension & brakes 2025-11-01 FP Add TB size to Ford Mustang (94-98) Spec Line #39130induction 2025-11-01 FP Correct Existing VW Scirocco Spec Line #39140weight 2025-10-01 FP HP Plymouth Arrow spec omission #38995wording 2025-10-01 FP Add Wheel Diameter to Appendix G #39008tyres & wheels 2025-10-01 FP Add TB ID tolerance to general Prod rules #39009induction
	Road America Runoffs 20252025-09-29	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%)											2:32.395David Strittmatter · fastest of 20 · top 5 within 2.9s+0.068s (+0.04%)	2:34.271Chris Bovis · fastest of 19 · top 5 within 1.8s+1.025s (+0.67%)	132.4David Strittmatter-1.1 mph (-0.8%)	+2.144squal +0.330s	101.4%qual 100.2%
21 rule changes (STL: 3, P2: 1, FP: 17)10 weight · 4 induction · 2 cars added · 1 engine · 1 tyres & wheels · 3 othershowhide 2025-08-01 STL Lotus Weight Reduction #38772weight -50 lbs 2025-07-01 FP BMW Z4 update #38490induction 2025-07-01 FP EP Fiat 124 Spider Competition Adjustment Request #38498weight -50 lbs 2025-06-01 FP Base Weight Adjustment for H-Production X1/9 Spec Lines #38255weight -50 lbs 2025-05-01 STL E&O: SMX Allowance in STL #37945weight 2025-04-01 FP Request for Classification of Chevrolet Spark #37755cars added 2025-04-01 FP Request to Lower Ford Festiva Minimum Weight to 1600 LBS #37939weight -100 lbs 2025-03-01 FP Request Competition Adjustment to BMW Z3 2.5L #37120induction 2025-03-01 FP FP Class Adjustments #37458weight 2025-03-01 FP Interpretation of Production Rules on Mirrors #37235other 2025-03-01 FP Weight Reduction for Honda S2000 #37466weight 2025-03-01 FP Mazda 1999 Miata 1.8L #37488weight -50 lbs 2025-03-01 FP Errors & Omissions #37648cars added 2025-03-01 FP GTL/FP consolidation 2025 Rules #37659induction 2025-02-21 FP Effective date for Jan 2025 GCR updates #37654induction 2025-01-01 FP Request to Reduce Weight of BMW 325i/is E30 (84-91) Spec Line #37119weight -50 lbs 2025-01-01 FP Fix Error in Spridget Spec Line #37437engine 2025-01-01 FP Create ruleset that allows GTL cars to run in FP #37485other 2024-12-01 P2 2000 cc Pinto Engine Car Weight #37187weight 2024-12-01 STL Request to Remove Miata Hubs from General category #37138tyres & wheels 2024-11-01 FP 1275 HP Spridget Level 2 Only #36518other
	Road America Runoffs 20242024-10-01	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%)						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%)	-21.923squal -22.658s	85.4%qual 84.9%	2:32.327Cliff Ira · fastest of 26 · top 5 within 2.1s+0.913s (+0.60%)	2:33.246Kevin Ruck · fastest of 24 · top 5 within 1.4s-0.787s (-0.51%)	133.5David Strittmatter+0.3 mph (+0.2%)	+3.001squal +2.264s	102.0%qual 101.5%
30 rule changes (STL: 4, P2: 5, FP: 21)10 weight · 6 engine · 5 induction · 2 cars added · 1 tyres & wheels · 3 wording · 3 othershowhide 2024-10-01 FP Errors/emissions Honda Civic/CRX #36700wording 2024-08-01 FP Errant entry in HP production line item #36231other 2024-06-01 FP NIssan 300ZX Z31 to EP #35830cars added 2024-06-01 FP RX7 1993 and Up Request In EP Spec Lines, classify #36031cars added 2024-06-01 FP Clean-up Multiple EP RX-8 Spec Lines In EP #36156wording 2024-05-01 FP Request to Replace CRX Plastic Panels #35876wording 2024-05-01 FP FP data and parity #35896induction 2024-05-01 P2 CN Spec ECU #35835engine 2024-05-01 P2 E&O - Correct FIA Group CN spec line notes #35900tyres & wheels 2024-03-01 FP GCR Correction - Redundant HP Spec Lines #35623engine 2024-03-01 FP Update FP Protege (01-03) Model Info #35715other 2024-02-01 FP Update 1988-1991 Civic to Match 1988-1991 CRX #35399weight 2024-02-01 STL ST Electric-Assisted Steering Systems #35066other 2024-02-01 STL BOP Adjustments #35112weight 2024-02-01 STL Mazda 12A #35320induction 2024-01-01 FP FP data #35060weight +25 lbs 2024-01-01 FP Request to Review Z3 2.5 Spec Line #35073weight +50 lbs 2024-01-01 FP Corrections to Honda Spec Lines in FP #35250induction 2024-01-01 FP Miata Alternate Head #35253weight -50 lbs 2024-01-01 FP Triumph GT6 Adjustments #35255weight 2024-01-01 FP Honda S2000 throttle body #35272induction 2024-01-01 FP Correction within Triumph TR8 Spec Line #35315engine 2024-01-01 FP Correction to EP 924S/944 Spec Line #35317weight 2024-01-01 P2 E&O - Clarify B.1 modified engine range in AMAC spec lines #35225engine 2024-01-01 P2 Replacement Engine Crankcase for 07/08 Suzuki GSX-R1000 Engines #35340engine 2024-01-01 STL Alternate Carburetor Request for 79-85 RX7 12a #35181induction 2023-12-01 FP Porsche 944/924S Rule Change Request #35002weight 2023-12-01 FP FP and HP Toyota Corolla #35030weight -43 lbs 2023-12-01 FP Triumph GT6 Adjustments #35054weight -30 lbs 2023-12-01 P2 Correct Table 1 for Engine Date Range Specifications #35182engine
	Virginia International Raceway Runoffs 20232023-09-23	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%)						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%)	-17.853squal -17.189s	85.9%qual 86.3%	2:08.248Cliff Ira · fastest of 21 · top 5 within 1.0s+2.031s (+1.61%)	2:07.787Cliff Ira · fastest of 20 · top 5 within 0.8s-9.854s (-7.16%)	133.7Cliff Ira+1.1 mph (+0.9%)	+1.105squal +2.469s	100.9%qual 102.0%
16 rule changes (STL: 2, P2: 8, FP: 6)3 cars added · 3 tyres & wheels · 3 weight · 2 engine · 2 induction · 1 wording · 2 othershowhide 2023-07-01 FP Correct Intake Valve Size on 1500cc Midget/Spitfire #34419induction 2023-07-01 FP ITC to FP? #34286other 2023-06-01 FP Request to Classify Sonic and Fiesta in HP #34264cars added 2023-06-01 STL Clarify STL table B - IT spec notes on Tires #34187tyres & wheels 2023-05-01 FP Classification Request for 1978 Toyota Celica #34097cars added 2023-05-01 P2 Clarify minimum side body height requirement #34143tyres & wheels 2023-05-01 P2 Clarify closed cockpit single seat car allowance #34144wording 2023-04-01 P2 Remove redundant effective date language and update engine table #34012engine 2023-04-01 P2 E&O - Correct dimensional equivalents #34038weight 2023-02-01 FP Request to Add Mazda Protege P5 to FP #33664other 2023-01-01 FP Review Limited Prep Port Matching Rules #33600induction 2023-01-01 P2 Request to Classify Sebeco NP01 #33378cars added 2023-01-01 P2 Radical spec line clarifications #33485weight 2023-01-01 P2 E&O original class intent #33519weight 2023-01-01 P2 Update Engine Table Spec Line B.1 #33608engine 2023-01-01 STL Spec MX5 in STL #33473tyres & wheels
	Virginia International Raceway Runoffs 20222022-09-24	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%)	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%)	+14.030squal -7.785s	111.0%qual 93.8%	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%)	+8.002squal -17.908s	106.3%qual 85.7%	2:06.217Eric Prill · fastest of 18 · top 5 within 1.5s-1.219s (-0.96%)	2:17.641Mason Workman · fastest of 15 · top 5 within 3.2s+9.565s (+7.47%)	132.5Cliff Ira+1.2 mph (+0.9%)	+9.809squal +0.743s	107.7%qual 100.6%
46 rule changes (STL: 5, F5: 6, P2: 10, FP: 25)13 induction · 8 engine · 6 tyres & wheels · 5 weight · 4 cars added · 1 aero · 3 wording · 6 othershowhide 2022-09-01 F5 Intake Boots Correction #33028induction 2022-09-01 FP Request to classify VW New Beetle 2.5L in EP #32725cars added 2022-09-01 FP Request Rotary Injection on Dual Y manifold #32775engine 2022-09-01 FP Request for Corrado Stroke & Displacement Correction #32985engine 2022-08-01 F5 Ensure availability of ECU for Rotax engines #32695engine 2022-07-01 F5 Clarify stepped exhaust header references #32743engine 2022-06-01 F5 593 carb boot availability and oil pump clarification #32527induction 2022-06-01 FP Subaru BRZ Model Years #32500other 2022-05-01 FP Weight Adjustment of Lotus 7 #32213weight +50 lbs 2022-05-01 FP EP MX-5 Global Cup Car #32218weight 2022-05-01 FP Please Class BMW 128i in EP #32370cars added 2022-05-01 FP Inconsistency in Body Work Descriptions #32396other 2022-05-01 FP Request to classify the 1999-2000 Mazda Protege in FP #32398cars added 2022-05-01 P2 E&O Clarification of Chassis Construction Requirements #32469tyres & wheels 2022-05-01 P2 Clean up P2 wording #32525wording 2022-04-01 FP Mazda RX8 with 13b Rotary #32170induction 2022-04-01 FP Request Idle control valve clarification #32178engine 2022-04-01 FP Correct FP BMW 325e/es Displacement #32394engine 2022-04-01 P2 After Market to Aftermarket #32373other 2022-03-01 F5 E&O class name #32194other 2022-03-01 FP EP Adjustments #31858induction 2022-03-01 FP 1999 3.8L Ford Mustang to EP? #31635weight 2022-03-01 FP Improved Touring Tires #32064tyres & wheels 2022-03-01 FP VW Golf Jetta 2.0L intake and exhaust size correction. #32173induction 2022-03-01 P2 Add spec line for Beasley B2 #32147weight 2022-03-01 P2 E&O Table 1 spec line wing terminology #32148aero 2022-03-01 P2 E&O class name #32196other 2022-03-01 STL Single TB Weight Modifiers #31449weight 2022-03-01 STL Improved Touring Tires #32063tyres & wheels 2022-02-01 FP Throttle Body and Idle Air #31800induction 2022-02-01 P2 E&O Engine section #31969engine 2022-01-01 F5 Data Box Mounting Plate #31638other 2022-01-01 FP Porsche 968 Engine Questions #31478induction 2022-01-01 FP PCS E. 2. n. 4. Add Axle Shaft to Allow FWD the Same Freedom #31592tyres & wheels 2022-01-01 FP BMW Z3 2.5L Spec Line #31724induction 2022-01-01 FP FP Del Sol VTEC #31859induction 2022-01-01 FP Standardize Level 2 Classifications in FP #31868induction 2022-01-01 P2 E&O letter #31539 – Control Area definition #31783tyres & wheels 2022-01-01 STL Throttling Device Clarification #31323induction 2022-01-01 STL Mazda Renesis Restriction #31467induction 2022-01-01 STL Clarification of 79-85 RX7 Spec line #31621wording 2021-12-01 FP 944S2 Restrictor #31396induction 2021-12-01 FP Classing Clarification for 1986 Toyota Corolla FX16 #31527cars added 2021-12-01 P2 BoP adjustment effective 1-1-22 #31538engine 2021-12-01 P2 E&O clarification of "Control Area" definition #31539tyres & wheels 2021-10-01 FP E&O; MR2 Track #31120wording
	Indianapolis Motor Speedway Runoffs 20212021-09-25	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	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	-19.571squal -9.046s	84.1%qual 91.9%	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	-27.389squal -18.430s	77.7%qual 83.5%	1:51.082Craig Chima · fastest of 39 · top 5 within 1.2s-1.009s (-0.90%)	1:59.933Cliff Ira · fastest of 33 · top 5 within 5.4s+6.926s (+6.13%)	131.8Cliff Ira	-2.778squal -0.583s	97.7%qual 99.5%
47 rule changes (STL: 15, F5: 3, P2: 8, FP: 21)9 engine · 9 weight · 8 cars added · 4 induction · 4 suspension & brakes · 3 tyres & wheels · 2 aero · 2 wording · 6 othershowhide 2021-09-01 P2 P2 CN Engine Rebuild Clarification #31000engine 2021-09-01 STL Request to clean up Spec MX-5 Redundancy #31069other 2021-08-01 F5 Clarify allowable assisted shifting systems #30871wording 2021-08-01 F5 Request to correct terminology #30976tyres & wheels 2021-08-01 FP Request to Allow F22c Engine for 2000-2003 Honda S2000 #30548engine 2021-08-01 FP Request a review of the S14 240SX in EP. #30873weight -200 lbs 2021-08-01 P2 F5 P2 Conversion #30856other 2021-08-01 P2 Clarify minimum body width requirement #30859tyres & wheels 2021-07-01 FP Lotus/Caterham 7 America Request #30392engine 2021-07-01 FP Request to classify ITC Plymouth Arrow #30588cars added 2021-07-01 FP Reclassification of the 1984/85 BMW 318i from FP to HP #30661cars added 2021-07-01 FP Fiat x1/9 Competition Adjustments #30711weight -50 lbs 2021-07-01 FP Reclassify Daimler SP 250 #30721cars added 2021-06-01 F5 Request to Allow Rotax 593 HO Engine #30712engine 2021-06-01 FP Move Porsche 924 in Level 1 Prep From EP to FP #30135cars added 2021-06-01 FP Clarify Application of Percentage Based Weight Penalties #30669weight 2021-06-01 STL VW Engine Request #30625engine 2021-05-01 FP Change Classification of 84-87 Mazda 626 from FP to HP #30350cars added 2021-05-01 FP Fiat X1/9 brake rotors #30423suspension & brakes 2021-05-01 P2 E&O tonneau cover provision in cockpit opening section #30459other 2021-05-01 P2 Remove effective dates in Table 1 #30468other 2021-05-01 P2 E&O Maximum Valves Per Cylinder #30560engine 2021-05-01 STL Solstice Ride Height #30183suspension & brakes 2021-05-01 STL Request Mazda B5 DOHC #30420cars added 2021-05-01 STL Honda B16A (JDM) Restrictor change #30531induction 2021-04-01 FP Please Classify Mazda3 in FP #30165cars added 2021-04-01 FP Golf MkIII Valve Size Request #30268engine 2021-04-01 STL ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wording 2021-03-01 P2 Add a new spec line for a 2-cycle, 3-cylinder engine up to 820cc #30272engine 2021-03-01 STL GM Ecotec engines in STL #30247engine 2021-03-01 STL Super Touring Alternate Miata Hubs #30345tyres & wheels 2021-02-01 STL Brake Component Relocation #29990suspension & brakes 2021-02-01 STL Super Touring Wing Clarification #30111aero 2021-02-01 STL Transmission Options #30118other 2021-01-01 FP Alternate Front Brake Rotors and Calipers for EP AH 3000 #29893suspension & brakes 2021-01-01 FP Request VW weight break #29963weight -50 lbs 2021-01-01 STL Request for FWD and RWD Parity #29728weight 2021-01-01 STL Request to Remove Honda F20C 2% Weight Penalty #29815weight 2021-01-01 STL Request for FWD and RWD Parity #30023induction 2020-12-01 FP Mk2 VW Consistency and Cleanup of FP and HP Spec Lines #29195weight -50 lbs 2020-12-01 FP Correct Wording for Level 1 and Level 2 Induction Systems #29406induction 2020-12-01 FP Weight Reduction for Datsun Roadster #29409weight -75 lbs 2020-12-01 FP EP TR8 Adjustment #29512weight -100 lbs 2020-12-01 FP Request to Classify 1996-2000 Honda Civic EX #29515cars added 2020-12-01 FP FAJS Carburetor #29576other 2020-12-01 P2 Balance of Performance adjustments effective 01-01-2021 #29822induction 2020-12-01 STL Request clarification on wing measurement #29640aero
	Road America Runoffs 20202020-10-02	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	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	-10.724squal -10.466s	93.0%qual 93.1%	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	-22.322squal -22.906s	85.3%qual 84.9%	2:31.414Ethan Shippert · fastest of 23 · top 5 within 2.2s	2:34.033Kevin Ruck · fastest of 21 · top 5 within 2.3s	133.2Sam Henry	+1.918squal -0.006s	101.3%qual 100.0%
42 rule changes (STL: 11, F5: 6, P2: 6, FP: 19)11 induction · 10 engine · 7 cars added · 4 weight · 2 aero · 2 tyres & wheels · 3 wording · 3 othershowhide 2020-10-01 F5 Request to Update Suzuki Engine Years for F500 #29453engine 2020-10-01 FP 84-87 Toyota Corolla HP Wheel Diameter Allowance Proposal E&O #29458tyres & wheels 2020-09-01 P2 E&O clarification of P2 rear wing requirements #29205aero 2020-08-01 FP EP BMW Z3 Rule Clarification #28998engine 2020-08-01 STL Minimum Weight Determination #27695weight 2020-08-01 STL ST Gurney flap Wicker clarification #29012aero 2020-07-01 F5 Request for Cockpit Adjustment of External Jetting Devices #28359other 2020-07-01 F5 Two Stroke Motors (reply to #28359 WDYT) #28816engine 2020-07-01 F5 Re letter requesting driver adjustable carb mixture #28840other 2020-07-01 F5 #28359 WDYT Request for Cockpit Adjustment #28875other 2020-07-01 FP Request to Classify Porsche 911 2.0L #28456cars added 2020-07-01 FP Request to change to Carburetor Spec Line 84-87 Mazda 626 #28926induction 2020-07-01 STL Request for Addition to GT3 Approved Turbo List #27576induction 2020-06-01 FP BMW Cylinder Head Casting and Part Numbers #28708engine 2020-06-01 FP Correct Scirocco Spec line E&O #28892weight 2020-06-01 P2 Classify Elan NP01 in P2 Table 1 #28812cars added 2020-06-01 STL Request to add 2016-2019 GMX-5 Spec line #28604cars added 2020-06-01 STL Request to update PN for MX-5 #28622wording 2020-06-01 STL Correction - Clarification Honda/Acura B18B engine Letter # 26209 #28873engine 2020-05-01 FP Request to Classify 1990-1994 Mazda Protege #28381cars added 2020-05-01 FP Error in Mini Cooper Spec Line #28713wording 2020-05-01 P2 SCCA Enterprises ESR / P2 engine restrictor testing #28669induction 2020-05-01 STL STL Honda B18 restrictor changes #28794induction 2020-04-01 FP Caterham 7 Spec Line #28498engine 2020-04-01 FP Request to classify SOHC 1989-90 240SX in F prod L2 #28553cars added 2020-04-01 P2 Add ESR inlet restrictor #27869induction 2020-04-01 STL Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0 #27884engine 2020-04-01 STL Acura/Honda B18C engine chart. Reduce the current 54 mm flat plat #28663induction 2020-04-01 STL Mazda MZR engine chart. Reduce the current 55 mm flat plate to 53 #28664induction 2020-03-01 FP VW Weight and Valve Size Request #27886weight 2020-03-01 FP Request to allow 40 DCOE carb for the Datsun 510 #28195induction 2020-03-01 FP Request to classify Porsche 914 2L in LPrep FProd #28231cars added 2020-03-01 FP Request Ford Fiesta Weight Adjustment #28336weight 2020-03-01 P2 Request for Fly by Wire Rule Wording Change #28247engine 2020-03-01 STL Request to add wheel part numbers #28342tyres & wheels 2020-02-01 FP Request for Help for Datsun 1200 #27934induction 2020-01-01 F5 Change 600cc restrictor size #27883induction 2020-01-01 FP Request to List Mazda Miata Throttle Body Size #27907induction 2020-01-01 FP Request to Classify 2001-2003 Mazda Protege ES in FP #27922cars added 2020-01-01 P2 Request for addition of BMW Engine in P2 Engine Table #27821engine 2019-12-01 FP Request to Correct Track of 1988-91 Honda Civic #27487wording 2019-12-01 FP Re-organize Prep2 Cylinder Head Rules for Clarity & Consistency #27661engine
	Virginia International Raceway Runoffs 20192019-10-05	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	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	-9.701squal -9.842s	92.4%qual 92.3%	1:49.111Robert Iversen · fastest of 14 · top 5 within 0.8s	1:50.258Greg Gyann · fastest of 13 · top 5 within 0.4s	149.4Robert Iversen	-17.015squal -18.092s	86.6%qual 85.8%	2:07.436Eric Prill · fastest of 19 · top 5 within 0.6s	2:08.076Eric Prill · fastest of 18 · top 5 within 0.8s	131.4Ken Kannard	+0.803squal +0.233s	100.6%qual 100.2%
30 rule changes (STL: 11, F5: 1, P2: 9, FP: 9)8 weight · 6 induction · 5 engine · 3 suspension & brakes · 2 cars added · 2 tyres & wheels · 2 wording · 2 othershowhide 2019-10-01 P2 Update Engine Table Line E notes #27414engine 2019-10-01 STL Request to Classify Spec MX-5 Challenge in STL #27399cars added 2019-08-31 F5 Request for Weight Increase for Motorcycle Powered Cars #27214weight +25 lbs 2019-08-31 FP Request bodywork for Austin Healey Bugeye Sprite MK1 #27106other 2019-08-31 FP Request to classify the GMX5 2019 #27263cars added 2019-08-31 FP level one susp. component rule #27270suspension & brakes 2019-08-31 FP Clarification of Carb Rules - Prep 1 #27300induction 2019-08-31 FP Clarification of Carb Rules - Prep 2 #27301induction 2019-08-31 P2 Update P2 Engine Table spec lines to reflect 3/1/2019 #27254engine 2019-08-01 FP Request Miata Eligibility - 2003 #27121other 2019-07-01 P2 E&O Transmissions #27006tyres & wheels 2019-07-01 STL Request clarification for manifold and throttle in STU #27004induction 2019-06-01 P2 Request to restrict all cars #26246weight 2019-05-31 STL Request Restrictor Plate correction #26779induction 2019-05-01 STL Request Ride Height Clarification #26597suspension & brakes 2019-04-01 FP Rollcenter Correction Clarification #25873tyres & wheels 2019-04-01 FP Hardtops #26476wording 2019-03-01 FP Request Classification of Dodge Daytona in F Production #26259weight -150 lbs 2019-03-01 P2 Change Engine Table Lines B.1 & B.5 #25777engine 2019-03-01 P2 Change Line A.1 restrictor size #26429induction 2019-03-01 STL Request to Allow VW 1.8L Engine #25614engine 2019-03-01 STL Request to reduce weight of RX8 with Renesis rotary #25781weight -100 lbs 2019-03-01 STL Request for Open Brake Pads On Mazda MX-5 Cup NC #25821suspension & brakes 2019-03-01 STL Request to clarify B18C1 GSR Honda B motor table #26209weight 2019-03-01 STL Port Matching #26415wording 2019-01-01 P2 Request to Allow 1345cc Hayabusa Engines for Spec Line P2 Cars #25595engine 2019-01-01 P2 Change CN inlet restrictor implementation date #25816induction 2019-01-01 P2 Clarify Honda K20A-FD2 parts requirement #25950weight 2019-01-01 STL Request to equalize FPR Reduction on all B-Series Vtec Engines #24746weight 2019-01-01 STL Request E&O for Mazda Miata Spec Line #25955weight
	Sonoma Raceway Runoffs 20182018-10-10	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	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	-7.263squal -7.331s	93.4%qual 93.3%	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	-17.683squal -20.354s	83.9%qual 81.4%	1:47.588Joe Huffaker · fastest of 15 · top 5 within 3.0s	1:48.481Joe Huffaker · fastest of 14 · top 5 within 2.2s	109.1Joe Huffaker	-1.273squal -1.550s	98.8%qual 98.6%
No rule changes on record between these events
	Indianapolis Motor Speedway Runoffs 20172017-09-25	1:52.647Adam Roberts · fastest of 57 · top 5 within 0.8s	1:52.589Eric Kutil · fastest of 50 · top 5 within 1.2s		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		-9.729squal -9.511s	91.4%qual 91.6%	1:31.826Jeff Shafer · fastest of 26 · top 5 within 4.9s	1:32.481Jeff Shafer · fastest of 24 · top 5 within 3.8s		-20.108squal -20.821s	82.1%qual 81.5%	1:52.091Eric Prill · fastest of 42 · top 5 within 1.2s	1:53.007Eric Prill · fastest of 40 · top 5 within 0.7s		+0.418squal -0.556s	100.4%qual 99.5%
No rule changes on record between these events
	Mid-Ohio Sports Car Course Runoffs 20162016-09-19	1:35.439John Schmitt · fastest of 34 · top 5 within 1.5s	1:36.625Kevin Boehm · fastest of 31 · top 5 within 0.6s		1:28.528Calvin Stewart · fastest of 14 · top 5 within 3.9s	1:29.853Steven Thompson · fastest of 12 · top 5 within 4.5s		-6.772squal -6.911s	93.0%qual 92.8%	1:20.188Jeff Shafer · fastest of 18 · top 5 within 4.0s	1:20.904Jeff Shafer · fastest of 16 · top 5 within 2.2s		-15.721squal -15.251s	83.7%qual 84.0%	1:35.938John Walker · fastest of 33 · top 5 within 0.4s	1:36.399John Walker · fastest of 27 · top 5 within 0.3s		-0.226squal +0.499s	99.8%qual 100.5%
No rule changes on record between these events
	Daytona International Speedway Runoffs 20152015-09-21	2:09.672Kevin Boehm · fastest of 37 · top 5 within 2.5s	2:10.269Kevin Boehm · fastest of 37 · top 5 within 2.1s		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		-6.971squal -7.848s	94.6%qual 93.9%	1:51.825Chris Farrell · fastest of 17 · top 5 within 3.6s	1:52.355Jeff Shafer · fastest of 17 · top 5 within 2.8s		-17.914squal -17.847s	86.2%qual 86.2%	2:11.009Kevin Ruck · fastest of 20 · top 5 within 1.6s	2:12.419Kevin Ruck · fastest of 18 · top 5 within 1.1s		+2.150squal +1.337s	101.7%qual 101.0%

By track

Track	Events	Typical % of STL	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 STL'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.