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BoP Lab / Classes / P2

P2 vs FE2 vs FB vs EP 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: remove one to add another)
Series
Reference · what % is measured against
Tracks · untick to narrow

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 · FB 99.0% of P2 J R Osborne, Daytona International Speedway Runoffs 2015 qualifying · EP 110.3% of P2 Jesse Prather, Virginia International Raceway Runoffs 2019 race

1:201:402:002:2019 rule changes between Runoffs 2018 and Runoffs 201919 ▾22 rule changes between Runoffs 2019 and Runoffs 202022 ▾22 rule changes between Runoffs 2020 and Runoffs 202122 ▾31 rule changes between Runoffs 2021 and Runoffs 202231 ▾21 rule changes between Runoffs 2022 and Runoffs 202321 ▾19 rule changes between Runoffs 2023 and Runoffs 202419 ▾16 rule changes between Runoffs 2024 and Runoffs 202516 ▾22 rule changes between Runoffs 2025 and Runoffs 202622 ▾P2 race best at Runoffs 2015: 1:52.355 (Jeff Shafer)P2 race best at Runoffs 2016: 1:20.904 (Jeff Shafer)P2 race best at Runoffs 2017: 1:32.481 (Jeff Shafer)P2 race best at Runoffs 2018: 1:32.071 (Chuck Bona)P2 race best at Runoffs 2019: 1:50.258 (Greg Gyann)P2 race best at Runoffs 2020: 2:09.793 (Robert Iversen)P2 race best at Runoffs 2021: 1:35.322 (Tim Day Jr)P2 race best at Runoffs 2022: 2:15.834 (Greg Gyann)P2 race best at Runoffs 2023: 1:48.829 (Lucian Pancea)P2 race best at Runoffs 2024: 2:08.322 (Bart Wolf)P2 race best at Runoffs 2026: 2:09.441 (Mike Reupert)P2 qualifying best at Runoffs 2015: 1:51.825 (Chris Farrell)P2 qualifying best at Runoffs 2016: 1:20.188 (Jeff Shafer)P2 qualifying best at Runoffs 2017: 1:31.826 (Jeff Shafer)P2 qualifying best at Runoffs 2018: 1:28.784 (Tim Day Jr)P2 qualifying best at Runoffs 2019: 1:49.111 (Robert Iversen)P2 qualifying best at Runoffs 2020: 2:08.514 (Robert Iversen)P2 qualifying best at Runoffs 2021: 1:33.235 (Tim Day Jr)P2 qualifying best at Runoffs 2022: 1:47.566 (Tim Day Jr)P2 qualifying best at Runoffs 2023: 1:48.590 (Greg Gyann)P2 qualifying best at Runoffs 2024: 2:07.405 (Bart Wolf)P2 qualifying best at Runoffs 2026: 2:10.606 (Greg Gyann)FE2 race best at Runoffs 2018: 1:35.563 (Flinn Lazier)FE2 race best at Runoffs 2019: 1:52.154 (Liam Snyder)FE2 race best at Runoffs 2020: 2:13.271 (Owen McAllister)FE2 race best at Runoffs 2021: 1:36.655 (Max Grau)FE2 race best at Runoffs 2022: 2:12.045 (Jason Conzo)FE2 race best at Runoffs 2023: 1:51.098 (Franklin Futrelle)FE2 race best at Runoffs 2024: 2:12.748 (Porter Aiken)FE2 race best at Runoffs 2025: 2:13.339 (Franklin Futrelle)FE2 race best at Runoffs 2026: 2:11.881 (Franklin Futrelle)FE2 qualifying best at Runoffs 2018: 1:35.040 (Flinn Lazier)FE2 qualifying best at Runoffs 2019: 1:51.062 (Liam Snyder)FE2 qualifying best at Runoffs 2020: 2:12.806 (Scott Rettich)FE2 qualifying best at Runoffs 2021: 1:36.395 (Max Grau)FE2 qualifying best at Runoffs 2022: 1:50.853 (Charles Russell Turner)FE2 qualifying best at Runoffs 2023: 1:50.665 (Charles Russell Turner)FE2 qualifying best at Runoffs 2024: 2:11.506 (Porter Aiken)FE2 qualifying best at Runoffs 2025: 2:12.475 (Franklin Futrelle)FE2 qualifying best at Runoffs 2026: 2:12.326 (Franklin Futrelle)FB race best at Runoffs 2015: 1:51.616 (J R Osborne)FB race best at Runoffs 2016: 1:21.015 (Jeremy Hill)FB race best at Runoffs 2017: 1:33.702 (Alex Mayer)FB race best at Runoffs 2018: 1:31.189 (J R Osborne)FB race best at Runoffs 2019: 1:57.688 (Pete Frost)FB qualifying best at Runoffs 2015: 1:50.711 (J R Osborne)FB qualifying best at Runoffs 2016: 1:19.886 (Alex Mayer)FB qualifying best at Runoffs 2017: 1:33.746 (Gary Hickman)FB qualifying best at Runoffs 2018: 1:28.612 (J R Osborne)FB qualifying best at Runoffs 2019: 1:54.469 (Pete Frost)EP race best at Runoffs 2015: 2:05.109 (Kip Van Steenburg)EP race best at Runoffs 2016: 1:34.266 (Michael Galati)EP race best at Runoffs 2017: 1:50.396 (Matt Reynolds)EP race best at Runoffs 2018: 1:46.518 (Glen McCready)EP race best at Runoffs 2019: 2:01.631 (Jesse Prather)EP race best at Runoffs 2020: 2:29.047 (Jesse Prather)EP race best at Runoffs 2021: 1:49.928 (Jesse Prather)EP race best at Runoffs 2022: 2:30.855 (Jesse Prather)EP race best at Runoffs 2023: 2:04.050 (Greg Ira)EP race best at Runoffs 2024: 2:27.869 (Tyler Ladd)EP race best at Runoffs 2025: 2:28.756 (Tyler Ladd)EP race best at Runoffs 2026: 2:27.869 (Jon Brakke)EP qualifying best at Runoffs 2015: 2:03.794 (Kip Van Steenburg)EP qualifying best at Runoffs 2016: 1:33.847 (Michael Galati)EP qualifying best at Runoffs 2017: 1:49.597 (Matt Reynolds)EP qualifying best at Runoffs 2018: 1:45.828 (Glen McCready)EP qualifying best at Runoffs 2019: 2:00.987 (Jesse Prather)EP qualifying best at Runoffs 2020: 2:27.322 (Jesse Prather)EP qualifying best at Runoffs 2021: 1:48.181 (Jesse Prather)EP qualifying best at Runoffs 2022: 2:02.326 (Jesse Prather)EP qualifying best at Runoffs 2023: 2:03.215 (John Hainsworth)EP qualifying best at Runoffs 2024: 2:26.803 (Tyler Ladd)EP qualifying best at Runoffs 2025: 2:27.293 (Jon Brakke)EP qualifying best at Runoffs 2026: 2:29.239 (Jon Brakke)Daytona International Speedway · Runoffs 2015R2015Mid-Ohio Sports Car Course · Runoffs 2016R2016Indianapolis Motor Speedway · Runoffs 2017R2017Sonoma Raceway · Runoffs 2018R2018Virginia International Raceway · Runoffs 2019R2019Road America · Runoffs 2020R2020Indianapolis Motor Speedway · Runoffs 2021R2021Virginia International Raceway · Runoffs 2022R2022Virginia International Raceway · Runoffs 2023R2023Road America · Runoffs 2024R2024Road America · Runoffs 2025R2025Road America · Runoffs 2026R2026
P2FE2FBEPsolid race · dashed qualifying · slower is lower
100%105%110%115%120%19 rule changes between Runoffs 2018 and Runoffs 201919 ▾22 rule changes between Runoffs 2019 and Runoffs 202022 ▾22 rule changes between Runoffs 2020 and Runoffs 202122 ▾31 rule changes between Runoffs 2021 and Runoffs 202231 ▾21 rule changes between Runoffs 2022 and Runoffs 202321 ▾19 rule changes between Runoffs 2023 and Runoffs 202419 ▾16 rule changes between Runoffs 2024 and Runoffs 202516 ▾22 rule changes between Runoffs 2025 and Runoffs 202622 ▾P2 race best at Runoffs 2015: 100.0% of P2's (Jeff Shafer)P2 race best at Runoffs 2016: 100.0% of P2's (Jeff Shafer)P2 race best at Runoffs 2017: 100.0% of P2's (Jeff Shafer)P2 race best at Runoffs 2018: 100.0% of P2's (Chuck Bona)P2 race best at Runoffs 2019: 100.0% of P2's (Greg Gyann)P2 race best at Runoffs 2020: 100.0% of P2's (Robert Iversen)P2 race best at Runoffs 2021: 100.0% of P2's (Tim Day Jr)P2 race best at Runoffs 2022: 100.0% of P2's (Greg Gyann)P2 race best at Runoffs 2023: 100.0% of P2's (Lucian Pancea)P2 race best at Runoffs 2024: 100.0% of P2's (Bart Wolf)P2 race best at Runoffs 2026: 100.0% of P2's (Mike Reupert)P2 qualifying best at Runoffs 2015: 100.0% of P2's (Chris Farrell)P2 qualifying best at Runoffs 2016: 100.0% of P2's (Jeff Shafer)P2 qualifying best at Runoffs 2017: 100.0% of P2's (Jeff Shafer)P2 qualifying best at Runoffs 2018: 100.0% of P2's (Tim Day Jr)P2 qualifying best at Runoffs 2019: 100.0% of P2's (Robert Iversen)P2 qualifying best at Runoffs 2020: 100.0% of P2's (Robert Iversen)P2 qualifying best at Runoffs 2021: 100.0% of P2's (Tim Day Jr)P2 qualifying best at Runoffs 2022: 100.0% of P2's (Tim Day Jr)P2 qualifying best at Runoffs 2023: 100.0% of P2's (Greg Gyann)P2 qualifying best at Runoffs 2024: 100.0% of P2's (Bart Wolf)P2 qualifying best at Runoffs 2026: 100.0% of P2's (Greg Gyann)FE2 race best at Runoffs 2018: 103.8% of P2's (Flinn Lazier)FE2 race best at Runoffs 2019: 101.7% of P2's (Liam Snyder)FE2 race best at Runoffs 2020: 102.7% of P2's (Owen McAllister)FE2 race best at Runoffs 2021: 101.4% of P2's (Max Grau)FE2 race best at Runoffs 2022: 97.2% of P2's (Jason Conzo)FE2 race best at Runoffs 2023: 102.1% of P2's (Franklin Futrelle)FE2 race best at Runoffs 2024: 103.4% of P2's (Porter Aiken)FE2 race best at Runoffs 2026: 101.9% of P2's (Franklin Futrelle)FE2 qualifying best at Runoffs 2018: 107.0% of P2's (Flinn Lazier)FE2 qualifying best at Runoffs 2019: 101.8% of P2's (Liam Snyder)FE2 qualifying best at Runoffs 2020: 103.3% of P2's (Scott Rettich)FE2 qualifying best at Runoffs 2021: 103.4% of P2's (Max Grau)FE2 qualifying best at Runoffs 2022: 103.1% of P2's (Charles Russell Turner)FE2 qualifying best at Runoffs 2023: 101.9% of P2's (Charles Russell Turner)FE2 qualifying best at Runoffs 2024: 103.2% of P2's (Porter Aiken)FE2 qualifying best at Runoffs 2026: 101.3% of P2's (Franklin Futrelle)FB race best at Runoffs 2015: 99.3% of P2's (J R Osborne)FB race best at Runoffs 2016: 100.1% of P2's (Jeremy Hill)FB race best at Runoffs 2017: 101.3% of P2's (Alex Mayer)FB race best at Runoffs 2018: 99.0% of P2's (J R Osborne)FB race best at Runoffs 2019: 106.7% of P2's (Pete Frost)FB qualifying best at Runoffs 2015: 99.0% of P2's (J R Osborne)FB qualifying best at Runoffs 2016: 99.6% of P2's (Alex Mayer)FB qualifying best at Runoffs 2017: 102.1% of P2's (Gary Hickman)FB qualifying best at Runoffs 2018: 99.8% of P2's (J R Osborne)FB qualifying best at Runoffs 2019: 104.9% of P2's (Pete Frost)EP race best at Runoffs 2015: 111.4% of P2's (Kip Van Steenburg)EP race best at Runoffs 2016: 116.5% of P2's (Michael Galati)EP race best at Runoffs 2017: 119.4% of P2's (Matt Reynolds)EP race best at Runoffs 2018: 115.7% of P2's (Glen McCready)EP race best at Runoffs 2019: 110.3% of P2's (Jesse Prather)EP race best at Runoffs 2020: 114.8% of P2's (Jesse Prather)EP race best at Runoffs 2021: 115.3% of P2's (Jesse Prather)EP race best at Runoffs 2022: 111.1% of P2's (Jesse Prather)EP race best at Runoffs 2023: 114.0% of P2's (Greg Ira)EP race best at Runoffs 2024: 115.2% of P2's (Tyler Ladd)EP race best at Runoffs 2026: 114.2% of P2's (Jon Brakke)EP qualifying best at Runoffs 2015: 110.7% of P2's (Kip Van Steenburg)EP qualifying best at Runoffs 2016: 117.0% of P2's (Michael Galati)EP qualifying best at Runoffs 2017: 119.4% of P2's (Matt Reynolds)EP qualifying best at Runoffs 2018: 119.2% of P2's (Glen McCready)EP qualifying best at Runoffs 2019: 110.9% of P2's (Jesse Prather)EP qualifying best at Runoffs 2020: 114.6% of P2's (Jesse Prather)EP qualifying best at Runoffs 2021: 116.0% of P2's (Jesse Prather)EP qualifying best at Runoffs 2022: 113.7% of P2's (Jesse Prather)EP qualifying best at Runoffs 2023: 113.5% of P2's (John Hainsworth)EP qualifying best at Runoffs 2024: 115.2% of P2's (Tyler Ladd)EP qualifying best at Runoffs 2026: 114.3% of P2's (Jon Brakke)Daytona International Speedway · Runoffs 2015R2015Mid-Ohio Sports Car Course · Runoffs 2016R2016Indianapolis Motor Speedway · Runoffs 2017R2017Sonoma Raceway · Runoffs 2018R2018Virginia International Raceway · Runoffs 2019R2019Road America · Runoffs 2020R2020Indianapolis Motor Speedway · Runoffs 2021R2021Virginia International Raceway · Runoffs 2022R2022Virginia International Raceway · Runoffs 2023R2023Road America · Runoffs 2024R2024Road America · Runoffs 2025R2025Road America · Runoffs 2026R2026
P2FE2FBEPsolid 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
EventP2FE2FBEP
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 20262026-09-282:10.606Greg 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 +1.720s101.9%qual 101.3%2:29.239Jon Brakke · fastest of 15 · top 5 within 5.2s+1.946s (+1.32%)2:27.869Jon Brakke · fastest of 15 · top 5 within 5.2s-0.887s (-0.60%)137.0Jon Brakke-3.8 mph (-2.7%)+18.428squal +18.633s114.2%qual 114.3%
22 rule changes (FE2: 1, EP: 21)4 induction · 4 weight · 3 cars added · 3 engine · 2 aero · 5 wording · 1 other · HP Mini Cooper 02-06 compression ratio increases from 10.6 to 11.0:1. · 1996-2000 Honda Civic CX/DX/LX with D16Y7 engine newly classified in HP. · HP 1275 Midget/Sprite alternate intake manifold from MG-B now permitted; balance tube shortening and flange modification allowed. · HP Honda Civic DX/LX 92–95 wheels 13x7 to 15x7, weight 2420 to 2350 lbs. · EP Honda S2000 gains permission to use Mugen hardtop P/N 0000-04-2312 or aftermarket equivalent. · EP Mazda MX-5 94-97 front track widens to 1516 mm, rear to 1534 mm. · EP Triumph GT6 auto-type drivetrain choke size increases from 44mm to 45mm. · EP BMW 325i/is E30 fuel injection throttle body specified as 60mm diameter. · EP Triumph TR2–TR4A may use 5-speed gearbox without overdrive; Weber carburetors and weight reference deleted. · EP BMW Z3 2.5L and other models get smaller restrictors, 50mm to 55mm, and Z3 2.5L weight rises 50 to 78 lbs. · EP Nissan 280Z minimum weight lowered to 2400 lbs, 2460 lbs with *, 2520 lbs with **. · EP Mazda MX-5 1.8L 90-97 minimum weight reduced to 2125 lbs. · HP Spec Lines Austin-Healey Sprite/Midget 1098cc minimum weight drops to 1550 lbs. · HP Volvo 142 P-1800 engine gains compression ratio limit 12.0:1 and valve lift limit .425 inch. · HP Mini DOHC 1.6 valve lift limit drops to .390" from .450". · FP and HP Volkswagen Rabbit descriptions updated to clarify Cabriolet body style inclusion. · EP, FP, HP: rear drum-to-disc brake conversion clarified; rotors solid, diameter limited to largest front rotor permitted. · EP Ford Mustang 94-98 fuel injected throttle body inside diameter set to 60. · HP Plymouth Arrow gains 4 or 5 speed transmission option specification. · Appendix G.2.3 clarifies rim width and diameter are absolute maximums; wording corrected from 'is' to 'are'. · EP, FP, HP throttle body inside dimensions and butterfly now allow +/-.25mm tolerance from stock. · FE and FE2 Enterprise bubble tail part WM138014 now allowed; FE2 must use this configuration only.showhide
  • EP Mini Cooper Compression Ratio #40517enginefasterengineHP Mini Cooper 02-06 compression ratio increases from 10.6 to 11.0:1.
  • EP 1996-2000 Honda Civic (CX, DX, VP, LX) with Engine Code D16Y7 #40322cars addedadded1996-2000 Honda Civic CX/DX/LX with D16Y7 engine newly classified in HP.
  • EP 1275 Midget/Sprit Alternate intake manifold E/O #40370inductionaddedinductionHP 1275 Midget/Sprite alternate intake manifold from MG-B now permitted; balance tube shortening and flange modification allowed.
  • EP HP Honda Civic (92-95) #40464weight -70 lbsfasterweightHP Honda Civic DX/LX 92–95 wheels 13x7 to 15x7, weight 2420 to 2350 lbs.
  • EP Honda S2000 Hardtop #40138aeroaddedaeroEP Honda S2000 gains permission to use Mugen hardtop P/N 0000-04-2312 or aftermarket equivalent.
  • EP Miata track width - errors and omissions #39976aerofasteraeroEP Mazda MX-5 94-97 front track widens to 1516 mm, rear to 1534 mm.
  • EP Triumph GT6 Spec Change. #40098inductionfasterinductionEP Triumph GT6 auto-type drivetrain choke size increases from 44mm to 45mm.
  • EP Request to Update E30 BMW Throttle Body Diameter Verbiage #39363wordingwordingEP BMW 325i/is E30 fuel injection throttle body specified as 60mm diameter.
  • EP TR2 Notes E&O #39180wordingwordingEP Triumph TR2–TR4A may use 5-speed gearbox without overdrive; Weber carburetors and weight reference deleted.
  • EP Balance of Power #39187induction +50 lbsslowerinductionEP BMW Z3 2.5L and other models get smaller restrictors, 50mm to 55mm, and Z3 2.5L weight rises 50 to 78 lbs.
  • EP Please Lower Weight of 280Z #38871weight -160 lbsfasterweightEP Nissan 280Z minimum weight lowered to 2400 lbs, 2460 lbs with *, 2520 lbs with **.
  • EP Miata Weight Adjustment Follow Up #38949weight -25 lbsfasterweightEP Mazda MX-5 1.8L 90-97 minimum weight reduced to 2125 lbs.
  • EP Weight Break for 1098 Midget / Sprite #38970weight -80 lbsfasterweightHP Spec Lines Austin-Healey Sprite/Midget 1098cc minimum weight drops to 1550 lbs.
  • EP HP Volvo 142 spec omission #38994engineslowerengineHP Volvo 142 P-1800 engine gains compression ratio limit 12.0:1 and valve lift limit .425 inch.
  • EP HP Mini DOHC 1.6 #38996engineslowerengineHP Mini DOHC 1.6 valve lift limit drops to .390" from .450".
  • EP Add to Rabbit description #39019wordingwordingFP and HP Volkswagen Rabbit descriptions updated to clarify Cabriolet body style inclusion.
  • EP Clean-up 9.1.5.E.7e #39025otherotherEP, FP, HP: rear drum-to-disc brake conversion clarified; rotors solid, diameter limited to largest front rotor permitted.
  • EP Add TB size to Ford Mustang (94-98) Spec Line #39130inductionaddedinductionEP Ford Mustang 94-98 fuel injected throttle body inside diameter set to 60.
  • EP HP Plymouth Arrow spec omission #38995cars addedaddedHP Plymouth Arrow gains 4 or 5 speed transmission option specification.
  • EP Add Wheel Diameter to Appendix G #39008wordingwordingAppendix G.2.3 clarifies rim width and diameter are absolute maximums; wording corrected from 'is' to 'are'.
  • EP Add TB ID tolerance to general Prod rules #39009wordingaddedEP, FP, HP throttle body inside dimensions and butterfly now allow +/-.25mm tolerance from stock.
  • FE2 FE & FE2 Bubble Tail #38978cars addedaddedFE and FE2 Enterprise bubble tail part WM138014 now allowed; FE2 must use this configuration only.
Road America Runoffs 20252025-09-292:12.475Franklin 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%)2:27.293Jon Brakke · fastest of 21 · top 5 within 2.1s+0.490s (+0.33%)2:28.756Tyler Ladd · fastest of 19 · top 5 within 1.9s+0.887s (+0.60%)140.8Jon Brakke+0.1 mph (+0.1%)
16 rule changes (P2: 1, FE2: 1, EP: 14)7 weight · 4 induction · 1 cars added · 1 engine · 1 wording · 2 other · EP BMW Z4 03-05 gains 52mm flat plate intake restrictor. · EP Fiat 124 Spider Competition 1600 and 2000 minimum weight drops 50 lbs to 2000; carburetors now allow 36mm chokes instead of 34mm. · HP Fiat X-1/9 and Bertone 1500 minimum weights reduced to 1740 lbs, 1784 lbs, 1827 lbs; 1300 models to 1600, 1640, 1680 lbs; additional 1300 and 1500 specs to 2010, 1900 lbs. · Chevrolet Spark 16-22 classified in HP Pre at 1850 lbs base, 1896 lbs modified, 1943 lbs. · HP Ford Festiva 88-93 minimum weight lowered to 1600 lbs, competition weight to 1640, prepared weight to 1680; compression ratio raised to 11.0:1. · FE2 allows pre-approved driver safety and comfort seat and control modifications for drivers with disabilities, per logbook. · EP BMW Z3 2.5L, Z3 2.8L, 328i E36/E46, 325i E36/E46 intake restrictors reduced 4mm each, to 52–58mm. · EP, FP, HP may use any interior or exterior mirror meeting rule 9.3.36. · EP Honda S2000 1997cc minimum weight drops 75 lbs to 2375; 2157cc drops 60 lbs to 2450. · EP Mazda MX-5 Miata 99-05 minimum weight reduced to 2100 lbs, 2153 lbs with power, 2205 lbs modified. · EP BMW models now require flat plate intake restrictors: Z3 2.5L 52mm, Z3 2.8L 55mm, 328i E36 58mm, 328i/ci E46 58mm, 325i E46 56mm, 325i E36 56mm, 325is M-Technic 56mm. · EP BMW 325i/is E30 84-91 weight reduced to 2150 lbs base, 2204 lbs with turbo, 2258 lbs supercharged. · EP Triumph GT6 switches to three Weber 40 DCOE carburetors with 28mm chokes, weight rises to 1990 lbs. · P2 2000 cc Pinto engine car minimum weight set to 1335 lbs. · HP 1275 Spridget compression ratio raised to 12.0:1; 1098cc also raised to 12.0:1. · EP Miata 1.6L, 1.8L 90–97, and 94–97 track width corrected to 1516/1534 mm (59.7/60.4 in.) front and rear.showhide
  • EP BMW Z4 update #38490inductionslowerinductionEP BMW Z4 03-05 gains 52mm flat plate intake restrictor.
  • EP EP Fiat 124 Spider Competition Adjustment Request #38498weight -50 lbsfasterweightEP Fiat 124 Spider Competition 1600 and 2000 minimum weight drops 50 lbs to 2000; carburetors now allow 36mm chokes instead of 34mm.
  • EP Base Weight Adjustment for H-Production X1/9 Spec Lines #38255weight -50 lbsfasterweightHP Fiat X-1/9 and Bertone 1500 minimum weights reduced to 1740 lbs, 1784 lbs, 1827 lbs; 1300 models to 1600, 1640, 1680 lbs; additional 1300 and 1500 specs to 2010, 1900 lbs.
  • EP Request for Classification of Chevrolet Spark #37755cars addedaddedChevrolet Spark 16-22 classified in HP Pre at 1850 lbs base, 1896 lbs modified, 1943 lbs.
  • EP Request to Lower Ford Festiva Minimum Weight to 1600 LBS #37939weight -100 lbsfasterweightHP Ford Festiva 88-93 minimum weight lowered to 1600 lbs, competition weight to 1640, prepared weight to 1680; compression ratio raised to 11.0:1.
  • FE2 Driver Safety & Comfort #37965otheraddedFE2 allows pre-approved driver safety and comfort seat and control modifications for drivers with disabilities, per logbook.
  • EP Request Competition Adjustment to BMW Z3 2.5L #37120inductionslowerinductionEP BMW Z3 2.5L, Z3 2.8L, 328i E36/E46, 325i E36/E46 intake restrictors reduced 4mm each, to 52–58mm.
  • EP Interpretation of Production Rules on Mirrors #37235wordingaddedEP, FP, HP may use any interior or exterior mirror meeting rule 9.3.36.
  • EP Weight Reduction for Honda S2000 #37466weightfasterweightEP Honda S2000 1997cc minimum weight drops 75 lbs to 2375; 2157cc drops 60 lbs to 2450.
  • EP Mazda 1999 Miata 1.8L #37488weight -50 lbsfasterweightEP Mazda MX-5 Miata 99-05 minimum weight reduced to 2100 lbs, 2153 lbs with power, 2205 lbs modified.
  • EP Effective date for Jan 2025 GCR updates #37654inductionslowerinductionEP BMW models now require flat plate intake restrictors: Z3 2.5L 52mm, Z3 2.8L 55mm, 328i E36 58mm, 328i/ci E46 58mm, 325i E46 56mm, 325i E36 56mm, 325is M-Technic 56mm.
  • EP Request to Reduce Weight of BMW 325i/is E30 (84-91) Spec Line #37119weight -50 lbsfasterweightEP BMW 325i/is E30 84-91 weight reduced to 2150 lbs base, 2204 lbs with turbo, 2258 lbs supercharged.
  • EP Triumph GT6 Adjustments #37112inductionfasterinductionEP Triumph GT6 switches to three Weber 40 DCOE carburetors with 28mm chokes, weight rises to 1990 lbs.
  • P2 2000 cc Pinto Engine Car Weight #37187weightslowerweightP2 2000 cc Pinto engine car minimum weight set to 1335 lbs.
  • EP 1275 HP Spridget Level 2 Only #36518enginefasterengineHP 1275 Spridget compression ratio raised to 12.0:1; 1098cc also raised to 12.0:1.
  • EP NA Miata Track Width Correction #36902otherotherEP Miata 1.6L, 1.8L 90–97, and 94–97 track width corrected to 1516/1534 mm (59.7/60.4 in.) front and rear.
Road America Runoffs 20242024-10-012:07.405Bart 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 +4.101s103.4%qual 103.2%2:26.803Tyler Ladd · fastest of 16 · top 5 within 4.1s-0.519s (-0.35%)2:27.869Tyler Ladd · fastest of 16 · top 5 within 3.6s-1.178s (-0.79%)140.7Bill Miller-1.0 mph (-0.7%)+19.547squal +19.398s115.2%qual 115.2%
19 rule changes (P2: 5, EP: 14)7 weight · 3 cars added · 1 engine · 1 induction · 1 removed · 6 wording · HP Volkswagen Golf and Jetta 85-92 track correction: front 1537 mm (60.5 in.), rear 1529 mm (60.2 in.). · Nissan 300ZX 84–89 added to EP, 2550–2678 lbs, 2960 cc SOHC, fuel injection, 12.0:1 compression, 0.500" valve lift limit. · Mazda RX-7 92-97 added to EP Prep as Level 2 rotary 13B 6-port, 2200–2310 lbs, carb or fuel injection, 42 mm choke. · EP Mazda RX-8 (04-11) alternate spec line removed; single spec line retained. · 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. · HP removes four redundant VW spec lines: Rabbit Cabriolet 1780, Scirocco 1588, Scirocco 1780 8-valve 83-88, Scirocco 1588. · HP Honda Civic 1.5 1988-91 minimum weight drops 70 lbs to 2175; also 2-speed and 3-speed minimums cut 72 and 73 lbs. · EP BMW Z3 2.5L minimum weight increased to 2500 lbs, 2563 lbs with power adder, 2625 lbs with two power adders. · EP Mazda MX-5 1.8L (90-97) minimum weight cut to 2150 lbs; (94-97) variants to 2000, 2050, 2100 lbs. · EP Triumph GT6 dual 1.75-inch carburetors weight rises to 1940 lbs; triple Weber 40 DCOE option added at 1990 lbs. · EP Honda S2000 fuel injected throttle body inside diameter increases from 62mm to 64mm. · EP Triumph TR8 dry sump allowance moved from Carburetor line to Notes. · EP Porsche 944/924S 2.5L and 2.7L minimum weights corrected: 2479cc to 2306–2363 lbs, 2681cc to 2358–2415 lbs. · 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. · EP Porsche 944/924S combines 2.5L and 2.7L variants (83-89), raises weight to 2250–2415 lbs, allows 2681cc displacement. · EP Triumph GT6 minimum weight drops to 1800 lbs. · 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
  • EP Errant entry in HP production line item #36231wordingwordingHP Volkswagen Golf and Jetta 85-92 track correction: front 1537 mm (60.5 in.), rear 1529 mm (60.2 in.).
  • EP NIssan 300ZX Z31 to EP #35830cars addedaddedNissan 300ZX 84–89 added to EP, 2550–2678 lbs, 2960 cc SOHC, fuel injection, 12.0:1 compression, 0.500" valve lift limit.
  • EP RX7 1993 and Up Request In EP Spec Lines, classify #36031cars addedaddedMazda RX-7 92-97 added to EP Prep as Level 2 rotary 13B 6-port, 2200–2310 lbs, carb or fuel injection, 42 mm choke.
  • EP Clean-up Multiple EP RX-8 Spec Lines In EP #36156cars addedremovedcars addedEP Mazda RX-8 (04-11) alternate spec line removed; single spec line retained.
  • P2 CN Spec ECU #35835wordingwordingP2 Spec Line E engine notes clarify oil system, ECU, and exhaust remain unrestricted; wording only.
  • 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.
  • EP GCR Correction - Redundant HP Spec Lines #35623removedremovedHP removes four redundant VW spec lines: Rabbit Cabriolet 1780, Scirocco 1588, Scirocco 1780 8-valve 83-88, Scirocco 1588.
  • EP Update 1988-1991 Civic to Match 1988-1991 CRX #35399weightfasterweightHP Honda Civic 1.5 1988-91 minimum weight drops 70 lbs to 2175; also 2-speed and 3-speed minimums cut 72 and 73 lbs.
  • EP Request to Review Z3 2.5 Spec Line #35073weight +50 lbsslowerweightEP BMW Z3 2.5L minimum weight increased to 2500 lbs, 2563 lbs with power adder, 2625 lbs with two power adders.
  • EP Miata Alternate Head #35253weight -50 lbsfasterweightEP Mazda MX-5 1.8L (90-97) minimum weight cut to 2150 lbs; (94-97) variants to 2000, 2050, 2100 lbs.
  • EP Triumph GT6 Adjustments #35255weightslowerweightEP Triumph GT6 dual 1.75-inch carburetors weight rises to 1940 lbs; triple Weber 40 DCOE option added at 1990 lbs.
  • EP Honda S2000 throttle body #35272inductionfasterinductionEP Honda S2000 fuel injected throttle body inside diameter increases from 62mm to 64mm.
  • EP Correction within Triumph TR8 Spec Line #35315wordingwordingEP Triumph TR8 dry sump allowance moved from Carburetor line to Notes.
  • EP Correction to EP 924S/944 Spec Line #35317weightweightEP Porsche 944/924S 2.5L and 2.7L minimum weights corrected: 2479cc to 2306–2363 lbs, 2681cc to 2358–2415 lbs.
  • 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.
  • P2 Replacement Engine Crankcase for 07/08 Suzuki GSX-R1000 Engines #35340engineaddedengineP2 Suzuki GSX-R1000 engine: 2007–2008 crankcase 11300-21860 may be replaced with 2016–2019 GSX-S1000 part 11301-04840.
  • EP Porsche 944/924S Rule Change Request #35002weightslowerweightEP Porsche 944/924S combines 2.5L and 2.7L variants (83-89), raises weight to 2250–2415 lbs, allows 2681cc displacement.
  • EP Triumph GT6 Adjustments #35054weight -30 lbsfasterweightEP Triumph GT6 minimum weight drops to 1800 lbs.
  • 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 20232023-09-231:48.590Greg 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 +2.075s102.1%qual 101.9%2:03.215John Hainsworth · fastest of 24 · top 5 within 4.3s+0.889s (+0.73%)2:04.050Greg Ira · fastest of 22 · top 5 within 5.3s-26.805s (-17.77%)144.6Greg Ira+3.1 mph (+2.2%)+15.221squal +14.625s114.0%qual 113.5%
21 rule changes (P2: 8, EP: 13)4 engine · 3 cars added · 1 induction · 1 removed · 1 suspension & brakes · 1 weight · 8 wording · 2 other · EP Triumph TR8 78-81 removes allowance for alternate front hubs of same external dimensions and weight. · EP Triumph GT6 carburetor type changes from SU or Stromberg to Auto-type, quantity two 1.5 inch. · EP Triumph GT6 Brakes Alt. now permits TR-6 standard or alternate calipers and discs. · FP and HP Sprite and Spitfire 1500 intake valve size corrected to 36.6 mm, removing prior decimal specifications. · EP Porsche 914-6 2.0L intake valve increased to 2.0 mm, exhaust valve corrected to 38.0 mm. · 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. · EP BMW Z3 2.5L flat plate intake restrictor reduced from 58mm to 56mm, both throttle bodies. · 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. · EP 79-85 RX-7 brake hub and rotor spec removed; 13B rotor housing and housing options now permitted. · EP Nissan 280Z carburetor option clarified: Hitachi-SU 1bbl 46mm throttle bores or fuel injection permitted. · EP Mazda RX-2, RX-3, RX-3SP, RX-7 12A gain 2 bbl fuel injected throttle body option; RX-7 13B gains fuel injected throttle body and stock fuel injection. · EP Mazda RX-2, RX-3, RX-3SP lose 50–52 lbs; RX-4 loses 50–52 lbs across all specs. · EP Triumph TR8 78-81 now allowed dry sump installation. · EP, FP, HP port matching limited to 1 inch depth from mating surface. · EP Prep adds Nissan 280ZX (79-83) at 2425–2546 lbs with 2760cc SOHC six, fuel injection, 12.0:1 compression limit, 0.500" valve lift limit. · 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.showhide
  • EP Hub Note Clean Up In EP TR8 Spec Line #34649removedremovedEP Triumph TR8 78-81 removes allowance for alternate front hubs of same external dimensions and weight.
  • EP Triumph GT6 Adjustments #34662engineengineEP Triumph GT6 carburetor type changes from SU or Stromberg to Auto-type, quantity two 1.5 inch.
  • EP Triumph GT6 Adjustments: Brakes #34663suspension & brakesaddedsuspension & brakesEP Triumph GT6 Brakes Alt. now permits TR-6 standard or alternate calipers and discs.
  • EP Correct Intake Valve Size on 1500cc Midget/Spitfire #34419wordingwordingFP and HP Sprite and Spitfire 1500 intake valve size corrected to 36.6 mm, removing prior decimal specifications.
  • EP 914-6 Valve Size Correction #34185enginefasterengineEP Porsche 914-6 2.0L intake valve increased to 2.0 mm, exhaust valve corrected to 38.0 mm.
  • P2 Clarify minimum side body height requirement #34143wordingwordingP2 minimum side body height must equal front axle centerline height, viewed from side.
  • P2 Clarify closed cockpit single seat car allowance #34144wordingwordingP2 closed cockpit single seat cars now prohibited unless Table 1 spec line permits.
  • EP Investigate Parity of Z3 #33343inductionslowerinductionEP BMW Z3 2.5L flat plate intake restrictor reduced from 58mm to 56mm, both throttle bodies.
  • 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.
  • P2 E&O - Correct dimensional equivalents #34038enginefasterengineP2 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.
  • EP Revise 79-85 RX7 Brake Spec Line Allowance #33293otherotherEP 79-85 RX-7 brake hub and rotor spec removed; 13B rotor housing and housing options now permitted.
  • EP Request alternate carburetors for EP 280z #33405wordingwordingEP Nissan 280Z carburetor option clarified: Hitachi-SU 1bbl 46mm throttle bores or fuel injection permitted.
  • EP Fuel Injection 12a Mazda RX3 #33434cars addedaddedEP Mazda RX-2, RX-3, RX-3SP, RX-7 12A gain 2 bbl fuel injected throttle body option; RX-7 13B gains fuel injected throttle body and stock fuel injection.
  • EP Mazda RX3 - Weight Reduction #33436weight -50 lbsfasterweightEP Mazda RX-2, RX-3, RX-3SP lose 50–52 lbs; RX-4 loses 50–52 lbs across all specs.
  • EP Request TR8 Dry Sump Allowance #33460otheraddedEP Triumph TR8 78-81 now allowed dry sump installation.
  • EP Review Limited Prep Port Matching Rules #33600wordingwordingEP, FP, HP port matching limited to 1 inch depth from mating surface.
  • EP 280ZX Classification Request #33611cars addedaddedEP Prep adds Nissan 280ZX (79-83) at 2425–2546 lbs with 2760cc SOHC six, fuel injection, 12.0:1 compression limit, 0.500" valve lift limit.
  • 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.
  • 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.
  • P2 E&O original class intent #33519wordingwordingP2 chassis now allows composite materials partially installed; anti-intrusion panels attachment simplified; Stohr and converted models clarified.
  • P2 Update Engine Table Spec Line B.1 #33608engine
Virginia International Raceway Runoffs 20222022-09-241:47.566Tim 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 +3.287s97.2%qual 103.1%2:02.326Jesse Prather · fastest of 17 · top 5 within 3.2s+1.339s (+1.11%)2:30.855Jesse Prather · fastest of 15 · top 5 within 2.5s+29.224s (+24.03%)141.5Jesse Prather-6.0 mph (-4.1%)+15.021squal +14.760s111.1%qual 113.7%
31 rule changes (P2: 10, EP: 21)4 cars added · 4 engine · 4 weight · 3 induction · 1 aero · 1 suspension & brakes · 1 tyres & wheels · 11 wording · 2 other · Volkswagen New Beetle 2.5L 5-cyl DOHC classified in EP at 2400–2520 lbs with fuel injection. · EP Mazda RX-7 12A/13B and 13B now permit 2 bbl fuel injected throttle body with 42mm chokes on dual-y manifold. · EP VW Corrado 92-95 stroke corrected to 90.3 mm and displacement to 2792 cc. · EP Subaru BRZ title updated to include model years 13–20; Toyota 86/Scion FR-S title likewise updated to 13–20. · EP Mazda MX-5 Global Cup 16-22 minimum weight set to 2400 lbs; sequential gearbox allowed with 150 lbs penalty. · BMW 128i (08-13) classified in EP at 2700 lbs minimum with 2996 cc engine, stock throttle body, 11.0:1 compression and 0.400" valve lift limits. · EP, FP, HP open cars now allow carbon fiber hardtops if they retain OEM exterior profiles. · 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. · EP Mazda RX-8 13B carburetor option replaced with fuel-injected throttle body or stock fuel injection. · EP, FP, HP Production clarify idle control valve options: stock original allowed, removable with blocked ports, or mechanical replaced with electronic stock type. · P2 Oldsmobile cam rules correct spelling from 'after market' to 'aftermarket' in two sections. · EP BMW Z3 2.5L intake restrictor reduced from 59mm to 58mm flat plate. · Ford Mustang 94-98 weight reduced to 2550/2614/2678 lbs; 99-03 3.8L classified EP at 2700/2768/2835 lbs. · EP, FP, HP Improved Touring cars may use any DOT-approved tyre as defined by 9.3.45. · 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. · EP, FP, HP: stock/original idle control devices permitted unmodified or completely removed with openings blocked. · EP Porsche 968 (92-95) now allowed to run dry sump. · EP 1979-1985 Mazda RX-7 12A and 13B minimum weights cut 50–53 lbs across all spec lines. · 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. · EP Porsche 968 intake valve size changes to 39.0 mm, 1.54 mm seat width. · EP, FP, HP front-wheel-drive cars may alter body and subframes to install alternate axle shaft, matching RWD freedom. · EP BMW Z3 2.5L adds alternate throttle body option with Turner adapter and permits head casting 1738400. · P2 Control Area definition clarified: rectangular zone from rear edge of front tires to front edge of rear tires, full car width. · EP Porsche 944S2 89-91 requires 56mm flat plate intake restrictor; compression ratio 12.0:1 max, valve lift 0.500" max, dry sump allowed. · Toyota Corolla GTS RWD (84-87) and FX16 FWD (87-88) added to HP; old Corolla (84-87) removed. · 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. · Toyota MR-2 1.6L 85-89 HP track width corrected to 15×47 / 15×47 inches; stock track baseline now 103% plus 2.5 inches.showhide
  • EP Request to classify VW New Beetle 2.5L in EP #32725cars addedaddedVolkswagen New Beetle 2.5L 5-cyl DOHC classified in EP at 2400–2520 lbs with fuel injection.
  • EP Request Rotary Injection on Dual Y manifold #32775inductionaddedinductionEP Mazda RX-7 12A/13B and 13B now permit 2 bbl fuel injected throttle body with 42mm chokes on dual-y manifold.
  • EP Request for Corrado Stroke & Displacement Correction #32985wordingwordingEP VW Corrado 92-95 stroke corrected to 90.3 mm and displacement to 2792 cc.
  • EP Subaru BRZ Model Years #32500wordingwordingEP Subaru BRZ title updated to include model years 13–20; Toyota 86/Scion FR-S title likewise updated to 13–20.
  • EP EP MX-5 Global Cup Car #32218weightweightEP Mazda MX-5 Global Cup 16-22 minimum weight set to 2400 lbs; sequential gearbox allowed with 150 lbs penalty.
  • EP Please Class BMW 128i in EP #32370cars addedaddedBMW 128i (08-13) classified in EP at 2700 lbs minimum with 2996 cc engine, stock throttle body, 11.0:1 compression and 0.400" valve lift limits.
  • EP Inconsistency in Body Work Descriptions #32396aeroaddedaeroEP, FP, HP open cars now allow carbon fiber hardtops if they retain OEM exterior profiles.
  • P2 E&O Clarification of Chassis Construction Requirements #32469wordingwordingP2 chassis construction clarified: full composite allowed; partial composite must roll without composite parts installed.
  • P2 Clean up P2 wording #32525wordingwordingP2 classification wording cleaned up in GCR section 9.1.8.C and GCR contents.
  • EP Mazda RX8 with 13b Rotary #32170engineengineEP Mazda RX-8 13B carburetor option replaced with fuel-injected throttle body or stock fuel injection.
  • EP Request Idle control valve clarification #32178wordingwordingEP, FP, HP Production clarify idle control valve options: stock original allowed, removable with blocked ports, or mechanical replaced with electronic stock type.
  • P2 After Market to Aftermarket #32373wordingwordingP2 Oldsmobile cam rules correct spelling from 'after market' to 'aftermarket' in two sections.
  • EP EP Adjustments #31858inductionslowerinductionEP BMW Z3 2.5L intake restrictor reduced from 59mm to 58mm flat plate.
  • EP 1999 3.8L Ford Mustang to EP? #31635weightfasterweightFord Mustang 94-98 weight reduced to 2550/2614/2678 lbs; 99-03 3.8L classified EP at 2700/2768/2835 lbs.
  • EP Improved Touring Tires #32064tyres & wheelsaddedtyres & wheelsEP, FP, HP Improved Touring cars may use any DOT-approved tyre as defined by 9.3.45.
  • 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.
  • 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.
  • P2 E&O class name #32196wordingwordingP2 Converted F5 cars renamed F500, must retain F500 suspension, minimum width 55 inches.
  • EP Throttle Body and Idle Air #31800wordingwordingEP, FP, HP: stock/original idle control devices permitted unmodified or completely removed with openings blocked.
  • EP Porsche 968 Engine Questions #31831engineaddedengineEP Porsche 968 (92-95) now allowed to run dry sump.
  • EP Request weight reduction for 1979-1985 Mazda RX-7 #31833weightfasterweightEP 1979-1985 Mazda RX-7 12A and 13B minimum weights cut 50–53 lbs across all spec lines.
  • P2 E&O Engine section #31969weightslowerweightP2 motorcycle engines gain 5cc to 1505cc max, two-stroke gains 5cc to 1205cc max, automotive engines add 50 lbs minimum weight to 1350 lbs.
  • EP Porsche 968 Engine Questions #31478engineengineEP Porsche 968 intake valve size changes to 39.0 mm, 1.54 mm seat width.
  • EP PCS E. 2. n. 4. Add Axle Shaft to Allow FWD the Same Freedom #31592otheraddedEP, FP, HP front-wheel-drive cars may alter body and subframes to install alternate axle shaft, matching RWD freedom.
  • EP BMW Z3 2.5L Spec Line #31724engineaddedengineEP BMW Z3 2.5L adds alternate throttle body option with Turner adapter and permits head casting 1738400.
  • 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.
  • EP 944S2 Restrictor #31396inductionslowerinductionEP Porsche 944S2 89-91 requires 56mm flat plate intake restrictor; compression ratio 12.0:1 max, valve lift 0.500" max, dry sump allowed.
  • EP Classing Clarification for 1986 Toyota Corolla FX16 #31527cars addedaddedToyota Corolla GTS RWD (84-87) and FX16 FWD (87-88) added to HP; old Corolla (84-87) removed.
  • P2 BoP adjustment effective 1-1-22 #31538otherunclearP2 specification line B.1 engine table entry amended; details of change not provided in excerpt.
  • 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.
  • EP E&O; MR2 Track #31120suspension & brakessuspension & brakesToyota MR-2 1.6L 85-89 HP track width corrected to 15×47 / 15×47 inches; stock track baseline now 103% plus 2.5 inches.
Indianapolis Motor Speedway Runoffs 20212021-09-251:33.235Tim 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 Iversen1:36.395Max Grau · fastest of 28 · top 5 within 0.7s1:36.655Max Grau · fastest of 28 · top 5 within 0.7s146.2Gray Fowler+1.333squal +3.160s101.4%qual 103.4%1:48.181Jesse Prather · fastest of 31 · top 5 within 3.2s-1.416s (-1.29%)1:49.928Jesse Prather · fastest of 27 · top 5 within 0.9s-0.468s (-0.42%)143.4Jon Brakke+14.606squal +14.946s115.3%qual 116.0%
22 rule changes (P2: 8, EP: 14)6 cars added · 4 weight · 2 engine · 1 induction · 7 wording · 2 other · P2 CN Honda K20A-FD2 engine rebuild clarified: balancing, porting, polishing prohibited; valve jobs and honing must follow factory procedures. · EP Honda S2000 now allows F22c engine in 1997cc and 2157cc displacements with revised weight brackets and specifications. · EP Nissan 240-SX S13/S14 weight drops to 2400 lbs base, 2460 turbo, 2520 supercharged; comp ratio raised to 12.0:1, valve lift to 0.500 inch. · 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. · EP Lotus/Caterham 7 America fuel injection permitted; IT preparation engine limitation removed. · Daimler SP 250 classified in EP with 2165 lbs minimum weight, 2548 cc eight-cylinder OHV engine, SU or Stromberg carburetors. · EP, FP, HP clarify percentage weight penalties sum before applying to base weight, round to nearest pound. · 84-87 Mazda 626 reclassified from FP to HP with 2300–2415 lb weight, 1998cc SOHC engine, two 32mm carburetors. · FP Fiat X1/9 and Bertone 1300 brake rotors now 257 x 12 mm, 10.1 inch diameter, 0.407 inch thickness. · EP Mazda MX-5 model year range corrected from 06-14 to 06-15. · 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. · Mazda 3 S 04-08 classified in EP at 2350 lbs minimum, 2.26L DOHC four-cylinder, fuel injected with 55mm throttle body, comp ratio 12.0:1 max, valve lift 0.500" max. · P2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front, 14–15 rear wheel width. · EP Austin-Healey 3000 gains option to use TR-6 front calipers and discs as alternate. · FP Mk2 Golf and Jetta 1.8 lose 50 lbs to 1900; HP Jetta GLI engine code removed. · EP, FP, HP Level 1 and Level 2 induction systems: carburettor jets, needles, metering rods allowed; throttle body porting permitted; wording clarified. · EP Nissan Datsun SRL 311U Roadster minimum weight reduced 75 lbs to 1925. · EP Triumph TR8 78-81 minimum weight drops to 2500 lbs. · 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
  • 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.
  • EP Request to Allow F22c Engine for 2000-2003 Honda S2000 #30548cars addedaddedEP Honda S2000 now allows F22c engine in 1997cc and 2157cc displacements with revised weight brackets and specifications.
  • EP Request a review of the S14 240SX in EP. #30873weight -200 lbsfasterweightEP Nissan 240-SX S13/S14 weight drops to 2400 lbs base, 2460 turbo, 2520 supercharged; comp ratio raised to 12.0:1, valve lift to 0.500 inch.
  • P2 F5 P2 Conversion #30856wordingwordingP2 Converted F5 cars must retain F5 suspension and meet P2 non-spec requirements except minimum width is 55 inches.
  • P2 Clarify minimum body width requirement #30859wordingwordingP2 minimum body width clarified: cannot extend inward beyond vertical plane through tire centerlines.
  • EP Lotus/Caterham 7 America Request #30392wordingwordingEP Lotus/Caterham 7 America fuel injection permitted; IT preparation engine limitation removed.
  • EP Reclassify Daimler SP 250 #30721cars addedaddedDaimler SP 250 classified in EP with 2165 lbs minimum weight, 2548 cc eight-cylinder OHV engine, SU or Stromberg carburetors.
  • EP Clarify Application of Percentage Based Weight Penalties #30669wordingwordingEP, FP, HP clarify percentage weight penalties sum before applying to base weight, round to nearest pound.
  • EP Change Classification of 84-87 Mazda 626 from FP to HP #30350cars addedadded84-87 Mazda 626 reclassified from FP to HP with 2300–2415 lb weight, 1998cc SOHC engine, two 32mm carburetors.
  • EP Fiat X1/9 brake rotors #30423otherotherFP Fiat X1/9 and Bertone 1300 brake rotors now 257 x 12 mm, 10.1 inch diameter, 0.407 inch thickness.
  • EP NC MX-5 year range correction E&O #30503cars addedaddedEP Mazda MX-5 model year range corrected from 06-14 to 06-15.
  • P2 E&O tonneau cover provision in cockpit opening section #30459wordingwordingP2 tonneau covers now allowed to meet minimum dimensions; cockpit equipment attachment wording clarified.
  • P2 Remove effective dates in Table 1 #30468wordingwordingP2 removes effective date 01/01/2021 from six car spec lines in Table 1.
  • P2 E&O Maximum Valves Per Cylinder #30560engineengineP2 engine specs B.1, B.2, B.3 limited to maximum 4 valves per cylinder.
  • EP Please Classify Mazda3 in FP #30165cars addedaddedMazda 3 S 04-08 classified in EP at 2350 lbs minimum, 2.26L DOHC four-cylinder, fuel injected with 55mm throttle body, comp ratio 12.0:1 max, valve lift 0.500" max.
  • 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.
  • EP Alternate Front Brake Rotors and Calipers for EP AH 3000 #29893otherotherEP Austin-Healey 3000 gains option to use TR-6 front calipers and discs as alternate.
  • EP Mk2 VW Consistency and Cleanup of FP and HP Spec Lines #29195weight -50 lbsfasterweightFP Mk2 Golf and Jetta 1.8 lose 50 lbs to 1900; HP Jetta GLI engine code removed.
  • EP Correct Wording for Level 1 and Level 2 Induction Systems #29406inductionfasterinductionEP, FP, HP Level 1 and Level 2 induction systems: carburettor jets, needles, metering rods allowed; throttle body porting permitted; wording clarified.
  • EP Weight Reduction for Datsun Roadster #29409weight -75 lbsfasterweightEP Nissan Datsun SRL 311U Roadster minimum weight reduced 75 lbs to 1925.
  • EP EP TR8 Adjustment #29512weight -100 lbsfasterweightEP Triumph TR8 78-81 minimum weight drops to 2500 lbs.
  • 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 20202020-10-022:08.514Robert Iversen · fastest of 12 · top 5 within 3.0s2:09.793Robert Iversen · fastest of 12 · top 5 within 3.9s153.1Robert Iversen2:12.806Scott Rettich · fastest of 25 · top 5 within 0.6s2:13.271Owen McAllister · fastest of 23 · top 5 within 0.7s143.4Owen McAllister+3.478squal +4.292s102.7%qual 103.3%2:27.322Jesse Prather · fastest of 20 · top 5 within 2.5s2:29.047Jesse Prather · fastest of 20 · top 5 within 2.8s141.7Jesse Prather+19.254squal +18.808s114.8%qual 114.6%
22 rule changes (P2: 6, FE2: 2, EP: 14)4 engine · 3 cars added · 3 induction · 2 weight · 1 aero · 7 wording · 2 other · HP 84-87 Toyota Corolla wheel diameter increases from 13 to 15 inches. · 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. · EP BMW Z3 2.5L cylinder head casting 1738400 permitted with iron block castings 1748933 or 1738566. · Porsche 911 S 67-68 classified in EP at 1800–1890 lbs, 1991cc opposed 6-cylinder SOHC with 36mm carburetors. · EP BMW 2.8L, 328i E36/E46, and 325i E36 now require iron blocks only; 325i E46 aluminum block removed. · Elan NP01 added to P2 Table 1 as Spec Line car with 2000cc displacement and 42mm restrictor. · FP Pre: 1990–1994 Mazda Protégé classified at 2150–2258 lbs, 1839cc DOHC, fuel injection, 11.0:1 compression, .450" valve lift limit. · HP Mini Cooper 02-06 and 07-13 convertible model years corrected to 05-08 and 09-15 respectively. · P2 Enterprises Sports Racer now permits 55mm flat plate intake restrictor Part # WM303013 as alternative to SIR. · EP Caterham 7 America engine limited to IT prep with specific sections, comp ratio 10.0:1, valve lift .380 inch. · P2 Enterprise Sports Racer 2.3L engine must use SIR or Flat Plate restrictor meeting peak horsepower, sized in whole or 0.5mm increments. · EP BMW 325is M-Technic 1994 minimum weight cut to 2550 lbs, modifier weights to 2614 and 2678. · HP Datsun 510 allows 40 DCOE carburetor option alongside existing 40 DCNF and 36mm DCNVH; auto side drafts moved to penalty structure. · EP fuel-injected BMW throttle body maximum inside diameter set to 64 mm. · P2 electronic throttle control wording clarified: ETC permitted if stock ECU throttle pedal activates original throttle shaft mechanism. · HP Datsun 1200 carburetor option changes from 26mm to 30mm choke(s) in 40 DCN, DCNF, IDF. · Mazda Miata models EP and FP throttle body specified 55mm, brake rotor thickness figures removed. · P2 adds BMW to permitted motorcycle-based engines alongside Kawasaki, Suzuki, Yamaha, Honda. · EP, FP, HP cylinder head rules reorganized for clarity; no performance change. · FE minimum weight rises to 1270 lbs; FE2 minimum weight rises to 1270 lbs; new spring options added; tire warmers prohibited.showhide
  • EP 84-87 Toyota Corolla HP Wheel Diameter Allowance Proposal E&O #29458otherfasterHP 84-87 Toyota Corolla wheel diameter increases from 13 to 15 inches.
  • FE2 FE/FE2 Oil Cooler #29293wordingwordingFE2 oil cooler rule clarified: Setrab 50-625-7612 or any cooler with max core 13 inches wide by 6.5 inches high allowed.
  • 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.
  • EP EP BMW Z3 Rule Clarification #28998wordingwordingEP BMW Z3 2.5L cylinder head casting 1738400 permitted with iron block castings 1748933 or 1738566.
  • EP Request to Classify Porsche 911 2.0L #28456cars addedaddedPorsche 911 S 67-68 classified in EP at 1800–1890 lbs, 1991cc opposed 6-cylinder SOHC with 36mm carburetors.
  • EP BMW Cylinder Head Casting and Part Numbers #28708engineslowerengineEP BMW 2.8L, 328i E36/E46, and 325i E36 now require iron blocks only; 325i E46 aluminum block removed.
  • 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.
  • EP Request to Classify 1990-1994 Mazda Protege #28381cars addedaddedFP Pre: 1990–1994 Mazda Protégé classified at 2150–2258 lbs, 1839cc DOHC, fuel injection, 11.0:1 compression, .450" valve lift limit.
  • EP Error in Mini Cooper Spec Line #28713wordingwordingHP Mini Cooper 02-06 and 07-13 convertible model years corrected to 05-08 and 09-15 respectively.
  • 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.
  • EP Caterham 7 Spec Line #28498wordingwordingEP Caterham 7 America engine limited to IT prep with specific sections, comp ratio 10.0:1, valve lift .380 inch.
  • P2 Add ESR inlet restrictor #27869inductionaddedinductionP2 Enterprise Sports Racer 2.3L engine must use SIR or Flat Plate restrictor meeting peak horsepower, sized in whole or 0.5mm increments.
  • EP Request to Review Horsepower Parity #27662induction
  • EP E36 (92-95) Brakes Errors and Omissions #28058weightfasterweightEP BMW 325is M-Technic 1994 minimum weight cut to 2550 lbs, modifier weights to 2614 and 2678.
  • EP Request to allow 40 DCOE carb for the Datsun 510 #28195engineaddedengineHP Datsun 510 allows 40 DCOE carburetor option alongside existing 40 DCNF and 36mm DCNVH; auto side drafts moved to penalty structure.
  • EP Add Throttle Body Size these EP BMW Spec Lines #28422engineslowerengineEP fuel-injected BMW throttle body maximum inside diameter set to 64 mm.
  • 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.
  • EP Request for Help for Datsun 1200 #27934inductionfasterinductionHP Datsun 1200 carburetor option changes from 26mm to 30mm choke(s) in 40 DCN, DCNF, IDF.
  • EP Request to List Mazda Miata Throttle Body Size #27907wordingwordingMazda Miata models EP and FP throttle body specified 55mm, brake rotor thickness figures removed.
  • P2 Request for addition of BMW Engine in P2 Engine Table #27821engineaddedengineP2 adds BMW to permitted motorcycle-based engines alongside Kawasaki, Suzuki, Yamaha, Honda.
  • EP Re-organize Prep2 Cylinder Head Rules for Clarity & Consistency #27661wordingwordingEP, FP, HP cylinder head rules reorganized for clarity; no performance change.
  • FE2 FE / FE2 Update Rules #27624weightslowerweightFE minimum weight rises to 1270 lbs; FE2 minimum weight rises to 1270 lbs; new spring options added; tire warmers prohibited.
Virginia International Raceway Runoffs 20192019-10-051:49.111Robert Iversen · fastest of 14 · top 5 within 0.8s1:50.258Greg Gyann · fastest of 13 · top 5 within 0.4s149.4Robert Iversen1:51.062Liam Snyder · fastest of 20 · top 5 within 1.3s1:52.154Liam Snyder · fastest of 19 · top 5 within 0.7s142.6Robert Vanman+1.896squal +1.951s101.7%qual 101.8%1:54.469Pete Frost · only car1:57.688Pete Frost · only car145.9Pete Frost+7.430squal +5.358s106.7%qual 104.9%2:00.987Jesse Prather · fastest of 29 · top 5 within 2.2s2:01.631Jesse Prather · fastest of 24 · top 5 within 1.4s147.5Kip Van Steenburg+11.373squal +11.876s110.3%qual 110.9%
19 rule changes (P2: 9, EP: 10)5 engine · 3 cars added · 2 aero · 2 induction · 2 weight · 5 wording · P2 Honda K20A-FD2 non-composite chassis intake restrictor note clarified; restrictor implementation date removed. · FP and HP Austin-Healey Sprite Mk I / MG Midget may replace rear bodywork aft of cockpit with alternate material stock-appearing components. · EP Mazda MX-5 Global Cup classification updated to include 2019 model year. · Production classes: suspension rule clarified to specify spindles, hubs, bushings, bearings, and ball joints unrestricted. · Production carburetor and fuel injection rules clarified: permitted optional carburetors listed, Weber and auto-type substitutions specified, fuel injection throttle body and butterfly dimensions detailed, intake manifold port extension pr… · EP, FP, HP carburetors: jets, needles, metering rods, needle valves unrestricted; choke parts removable; stock or optional Weber 40 DCN permitted; Weber types, auto types listed. · 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. · EP Mazda MX-5/Miata model years expand from 1999-2002 to 1999-2005. · 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. · EP Mazda RX-8 firewall may be modified for 13B engine fitment and must be sealed. · EP, FP, HP: clarified that tapered holes in ball joints can be reamed for bolt conversion, and wheel bearings and hubs unrestricted on all axles. · EP open cars may now use aftermarket hardtops if OEM-appearance and non-carbon-fiber; specific model allowances removed as redundant. · EP Mazda RX-7 12A and 13B (79-85) lose up to 75 lbs; 13B (86-91) loses up to 79 lbs across three weight classes. · 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. · 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
  • P2 Update Engine Table Line E notes #27414wordingwordingP2 Honda K20A-FD2 non-composite chassis intake restrictor note clarified; restrictor implementation date removed.
  • EP Request bodywork for Austin Healey Bugeye Sprite MK1 #27106aeroaddedaeroFP and HP Austin-Healey Sprite Mk I / MG Midget may replace rear bodywork aft of cockpit with alternate material stock-appearing components.
  • EP Request to classify the GMX5 2019 #27263cars addedaddedEP Mazda MX-5 Global Cup classification updated to include 2019 model year.
  • EP level one susp. component rule #27270wordingwordingProduction classes: suspension rule clarified to specify spindles, hubs, bushings, bearings, and ball joints unrestricted.
  • EP Clarification of Carb Rules - Prep 1 #27300wordingwordingProduction carburetor and fuel injection rules clarified: permitted optional carburetors listed, Weber and auto-type substitutions specified, fuel injection throttle body and butterfly dimensions detailed, intake manifold port extension pr…
  • EP Clarification of Carb Rules - Prep 2 #27301inductioninductionEP, FP, HP carburetors: jets, needles, metering rods, needle valves unrestricted; choke parts removable; stock or optional Weber 40 DCN permitted; Weber types, auto types listed.
  • P2 Update P2 Engine Table spec lines to reflect 3/1/2019 #27254engineslowerengineP2 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.
  • EP Request Miata Eligibility - 2003 #27121cars addedaddedEP Mazda MX-5/Miata model years expand from 1999-2002 to 1999-2005.
  • P2 E&O Transmissions #27006engineslowerengineP2 cars limited to power application on maximum two wheels.
  • P2 Request to restrict all cars #26246weightslowerweightP2 Enterprise minimum weight increased to 1375 lbs.; peak horsepower of sealed ESR engine reduced per CRB specification.
  • EP Allow Firewall Modification for Fitment of 13B into RX8 #26726engineaddedengineEP Mazda RX-8 firewall may be modified for 13B engine fitment and must be sealed.
  • EP Rollcenter Correction Clarification #25873wordingaddedEP, FP, HP: clarified that tapered holes in ball joints can be reamed for bolt conversion, and wheel bearings and hubs unrestricted on all axles.
  • EP Hardtops #26476aeroaddedaeroEP open cars may now use aftermarket hardtops if OEM-appearance and non-carbon-fiber; specific model allowances removed as redundant.
  • EP Request for Competition Adjustment for 2nd Generation RX7 #25935weight -50 lbsfasterweightEP Mazda RX-7 12A and 13B (79-85) lose up to 75 lbs; 13B (86-91) loses up to 79 lbs across three weight classes.
  • P2 Change Engine Table Lines B.1 & B.5 #25777inductionslowerinductionP2 stock and modified engines get smaller restrictors (35.0mm, 34.0mm, 33.0mm) and heavier minimums (1025, 1125, 1185 lbs).
  • P2 Change Line A.1 restrictor size #26429engineslowerengineP2 Line A.1 restrictor reduced from 40mm to 38mm.
  • 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.
  • 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.
  • P2 Clarify Honda K20A-FD2 parts requirement #25950engineslowerengineP2 Honda K20A-FD2 Group CN must use stock intake manifold, 64mm throttle, 55mm restrictor at 1500 lbs minimum.
Sonoma Raceway Runoffs 20182018-10-101:28.784Tim Day Jr · fastest of 17 · top 5 within 5.0s1:32.071Chuck Bona · fastest of 18 · top 5 within 0.9s144.4Tim Day Jr1:35.040Flinn Lazier · fastest of 9 · top 5 within 1.5s1:35.563Flinn Lazier · fastest of 9 · top 5 within 1.7s126.8Scott Rettich+3.492squal +6.256s103.8%qual 107.0%1:28.612J R Osborne · fastest of 7 · top 5 within 3.3s1:31.189J R Osborne · fastest of 7 · top 5 within 3.7s140.5J R Osborne-0.882squal -0.172s99.0%qual 99.8%1:45.828Glen McCready · fastest of 18 · top 5 within 4.3s1:46.518Glen McCready · fastest of 16 · top 5 within 2.8s106.5Aaron Downey+14.447squal +17.044s115.7%qual 119.2%
No rule changes on record between these events
Indianapolis Motor Speedway Runoffs 20172017-09-251:31.826Jeff Shafer · fastest of 26 · top 5 within 4.9s1:32.481Jeff Shafer · fastest of 24 · top 5 within 3.8s1:33.746Gary Hickman · fastest of 18 · top 5 within 3.3s1:33.702Alex Mayer · fastest of 17 · top 5 within 3.0s+1.221squal +1.920s101.3%qual 102.1%1:49.597Matt Reynolds · fastest of 44 · top 5 within 1.2s1:50.396Matt Reynolds · fastest of 45 · top 5 within 0.5s+17.915squal +17.771s119.4%qual 119.4%
No rule changes on record between these events
Mid-Ohio Sports Car Course Runoffs 20162016-09-191:20.188Jeff Shafer · fastest of 18 · top 5 within 4.0s1:20.904Jeff Shafer · fastest of 16 · top 5 within 2.2s1:19.886Alex Mayer · fastest of 10 · top 5 within 1.5s1:21.015Jeremy Hill · fastest of 10 · top 5 within 1.2s+0.111squal -0.302s100.1%qual 99.6%1:33.847Michael Galati · fastest of 25 · top 5 within 0.8s1:34.266Michael Galati · fastest of 23 · top 5 within 1.3s+13.362squal +13.659s116.5%qual 117.0%
No rule changes on record between these events
Daytona International Speedway Runoffs 20152015-09-211:51.825Chris Farrell · fastest of 17 · top 5 within 3.6s1:52.355Jeff Shafer · fastest of 17 · top 5 within 2.8s1:50.711J R Osborne · fastest of 20 · top 5 within 1.1s1:51.616J R Osborne · fastest of 19 · top 5 within 2.1s-0.739squal -1.114s99.3%qual 99.0%2:03.794Kip Van Steenburg · fastest of 29 · top 5 within 3.2s2:05.109Kip Van Steenburg · fastest of 28 · top 5 within 3.3s+12.754squal +11.969s111.4%qual 110.7%

By track

TrackEvents Typical % of P2 Best Latest 
Road America4100.0%3 of 4 with P2100.0%Runoffs 2020100.0%Runoffs 2026
Virginia International Raceway3100.0%100.0%Runoffs 2019100.0%Runoffs 2023
Indianapolis Motor Speedway2100.0%100.0%Runoffs 2017100.0%Runoffs 2021
Daytona International Speedway1100.0%100.0%Runoffs 2015100.0%Runoffs 2015
Mid-Ohio Sports Car Course1100.0%100.0%Runoffs 2016100.0%Runoffs 2016
Sonoma Raceway1100.0%100.0%Runoffs 2018100.0%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.