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BoP Lab / Classes / GTL

GTL vs FB vs FV vs EP pace at every track

Lap times across years say as much about the weather as the class. % of GTL is each class's best lap as a share of GTL'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: GTL 100.0% of GTL Jim Dentici, Daytona International Speedway Runoffs 2015 race · FB 82.1% of GTL J R Osborne, Sonoma Raceway Runoffs 2018 qualifying · FV 97.8% of GTL Andrew Whitston, Virginia International Raceway Runoffs 2022 race · EP 93.7% of GTL Kip Van Steenburg, Daytona International Speedway Runoffs 2015 race

1:201:402:002:202:4029 rule changes between Runoffs 2018 and Runoffs 201929 ▾37 rule changes between Runoffs 2019 and Runoffs 202037 ▾22 rule changes between Runoffs 2020 and Runoffs 202122 ▾28 rule changes between Runoffs 2021 and Runoffs 202228 ▾20 rule changes between Runoffs 2022 and Runoffs 202320 ▾32 rule changes between Runoffs 2023 and Runoffs 202432 ▾17 rule changes between Runoffs 2024 and Runoffs 202517 ▾22 rule changes between Runoffs 2025 and Runoffs 202622 ▾GTL race best at Runoffs 2015: 2:13.564 (Jim Dentici)GTL race best at Runoffs 2016: 1:35.912 (Kyle Disque)GTL race best at Runoffs 2017: 1:52.068 (Christopher Bovis)GTL race best at Runoffs 2018: 1:49.458 (Troy Ermish)GTL race best at Runoffs 2019: 2:07.837 (Bill Ball)GTL race best at Runoffs 2020: 2:31.601 (Peter Shadowen)GTL race best at Runoffs 2021: 1:51.952 (Scott Twomey)GTL race best at Runoffs 2022: 2:21.180 (Michael Lewis)GTL race best at Runoffs 2023: 2:11.277 (Graham Fuller)GTL race best at Runoffs 2024: 2:30.844 (Chris Bovis)GTL qualifying best at Runoffs 2015: 2:11.387 (Jim Dentici)GTL qualifying best at Runoffs 2016: 1:35.377 (Wilson Wright)GTL qualifying best at Runoffs 2017: 1:50.331 (Christopher Bovis)GTL qualifying best at Runoffs 2018: 1:47.885 (Troy Ermish)GTL qualifying best at Runoffs 2019: 2:06.997 (Peter Shadowen)GTL qualifying best at Runoffs 2020: 2:31.943 (Chris Bovis)GTL qualifying best at Runoffs 2021: 1:51.819 (Christopher Bovis)GTL qualifying best at Runoffs 2022: 2:07.789 (Peter Shadowen)GTL qualifying best at Runoffs 2023: 2:09.564 (Peter Shadowen)GTL qualifying best at Runoffs 2024: 2:30.858 (Peter Shadowen)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)FV race best at Runoffs 2015: 2:21.142 (Andrew Whitston)FV race best at Runoffs 2016: 1:38.066 (Flinn Lazier)FV race best at Runoffs 2017: 1:55.923 (Michael Varacins)FV race best at Runoffs 2018: 1:53.639 (Alex Scaler)FV race best at Runoffs 2019: 2:18.289 (Zachary Whitston)FV race best at Runoffs 2020: 2:45.816 (Alex Scaler)FV race best at Runoffs 2021: 1:57.234 (Alex Scaler)FV race best at Runoffs 2022: 2:18.093 (Andrew Whitston)FV race best at Runoffs 2023: 2:16.611 (Andrew Abbott)FV race best at Runoffs 2024: 2:44.834 (Andrew Abbott)FV race best at Runoffs 2025: 2:46.736 (Zachary Whitston)FV race best at Runoffs 2026: 2:45.272 (Brian Farnham)FV qualifying best at Runoffs 2015: 2:21.167 (Roger Siebenaler)FV qualifying best at Runoffs 2016: 1:37.942 (Alex Scaler)FV qualifying best at Runoffs 2017: 1:55.759 (Michael Varacins)FV qualifying best at Runoffs 2018: 1:52.637 (Skip Streets)FV qualifying best at Runoffs 2019: 2:15.712 (Andrew Whitston)FV qualifying best at Runoffs 2020: 2:43.994 (Hunter Phelps-Barron)FV qualifying best at Runoffs 2021: 1:57.479 (Andrew Whitston)FV qualifying best at Runoffs 2022: 2:15.116 (Brian Farnham)FV qualifying best at Runoffs 2023: 2:15.639 (Andrew Whitston)FV qualifying best at Runoffs 2024: 2:42.643 (Andrew Whitston)FV qualifying best at Runoffs 2025: 2:44.101 (Andrew Abbott)FV qualifying best at Runoffs 2026: 2:46.536 (Zachary Whitston)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
GTLFBFVEPsolid race · dashed qualifying · slower is lower
90%100%110%29 rule changes between Runoffs 2018 and Runoffs 201929 ▾37 rule changes between Runoffs 2019 and Runoffs 202037 ▾22 rule changes between Runoffs 2020 and Runoffs 202122 ▾28 rule changes between Runoffs 2021 and Runoffs 202228 ▾20 rule changes between Runoffs 2022 and Runoffs 202320 ▾32 rule changes between Runoffs 2023 and Runoffs 202432 ▾17 rule changes between Runoffs 2024 and Runoffs 202517 ▾22 rule changes between Runoffs 2025 and Runoffs 202622 ▾GTL race best at Runoffs 2015: 100.0% of GTL's (Jim Dentici)GTL race best at Runoffs 2016: 100.0% of GTL's (Kyle Disque)GTL race best at Runoffs 2017: 100.0% of GTL's (Christopher Bovis)GTL race best at Runoffs 2018: 100.0% of GTL's (Troy Ermish)GTL race best at Runoffs 2019: 100.0% of GTL's (Bill Ball)GTL race best at Runoffs 2020: 100.0% of GTL's (Peter Shadowen)GTL race best at Runoffs 2021: 100.0% of GTL's (Scott Twomey)GTL race best at Runoffs 2022: 100.0% of GTL's (Michael Lewis)GTL race best at Runoffs 2023: 100.0% of GTL's (Graham Fuller)GTL race best at Runoffs 2024: 100.0% of GTL's (Chris Bovis)GTL qualifying best at Runoffs 2015: 100.0% of GTL's (Jim Dentici)GTL qualifying best at Runoffs 2016: 100.0% of GTL's (Wilson Wright)GTL qualifying best at Runoffs 2017: 100.0% of GTL's (Christopher Bovis)GTL qualifying best at Runoffs 2018: 100.0% of GTL's (Troy Ermish)GTL qualifying best at Runoffs 2019: 100.0% of GTL's (Peter Shadowen)GTL qualifying best at Runoffs 2020: 100.0% of GTL's (Chris Bovis)GTL qualifying best at Runoffs 2021: 100.0% of GTL's (Christopher Bovis)GTL qualifying best at Runoffs 2022: 100.0% of GTL's (Peter Shadowen)GTL qualifying best at Runoffs 2023: 100.0% of GTL's (Peter Shadowen)GTL qualifying best at Runoffs 2024: 100.0% of GTL's (Peter Shadowen)FB race best at Runoffs 2015: 83.6% of GTL's (J R Osborne)FB race best at Runoffs 2016: 84.5% of GTL's (Jeremy Hill)FB race best at Runoffs 2017: 83.6% of GTL's (Alex Mayer)FB race best at Runoffs 2018: 83.3% of GTL's (J R Osborne)FB race best at Runoffs 2019: 92.1% of GTL's (Pete Frost)FB qualifying best at Runoffs 2015: 84.3% of GTL's (J R Osborne)FB qualifying best at Runoffs 2016: 83.8% of GTL's (Alex Mayer)FB qualifying best at Runoffs 2017: 85.0% of GTL's (Gary Hickman)FB qualifying best at Runoffs 2018: 82.1% of GTL's (J R Osborne)FB qualifying best at Runoffs 2019: 90.1% of GTL's (Pete Frost)FV race best at Runoffs 2015: 105.7% of GTL's (Andrew Whitston)FV race best at Runoffs 2016: 102.2% of GTL's (Flinn Lazier)FV race best at Runoffs 2017: 103.4% of GTL's (Michael Varacins)FV race best at Runoffs 2018: 103.8% of GTL's (Alex Scaler)FV race best at Runoffs 2019: 108.2% of GTL's (Zachary Whitston)FV race best at Runoffs 2020: 109.4% of GTL's (Alex Scaler)FV race best at Runoffs 2021: 104.7% of GTL's (Alex Scaler)FV race best at Runoffs 2022: 97.8% of GTL's (Andrew Whitston)FV race best at Runoffs 2023: 104.1% of GTL's (Andrew Abbott)FV race best at Runoffs 2024: 109.3% of GTL's (Andrew Abbott)FV qualifying best at Runoffs 2015: 107.4% of GTL's (Roger Siebenaler)FV qualifying best at Runoffs 2016: 102.7% of GTL's (Alex Scaler)FV qualifying best at Runoffs 2017: 104.9% of GTL's (Michael Varacins)FV qualifying best at Runoffs 2018: 104.4% of GTL's (Skip Streets)FV qualifying best at Runoffs 2019: 106.9% of GTL's (Andrew Whitston)FV qualifying best at Runoffs 2020: 107.9% of GTL's (Hunter Phelps-Barron)FV qualifying best at Runoffs 2021: 105.1% of GTL's (Andrew Whitston)FV qualifying best at Runoffs 2022: 105.7% of GTL's (Brian Farnham)FV qualifying best at Runoffs 2023: 104.7% of GTL's (Andrew Whitston)FV qualifying best at Runoffs 2024: 107.8% of GTL's (Andrew Whitston)EP race best at Runoffs 2015: 93.7% of GTL's (Kip Van Steenburg)EP race best at Runoffs 2016: 98.3% of GTL's (Michael Galati)EP race best at Runoffs 2017: 98.5% of GTL's (Matt Reynolds)EP race best at Runoffs 2018: 97.3% of GTL's (Glen McCready)EP race best at Runoffs 2019: 95.1% of GTL's (Jesse Prather)EP race best at Runoffs 2020: 98.3% of GTL's (Jesse Prather)EP race best at Runoffs 2021: 98.2% of GTL's (Jesse Prather)EP race best at Runoffs 2022: 106.9% of GTL's (Jesse Prather)EP race best at Runoffs 2023: 94.5% of GTL's (Greg Ira)EP race best at Runoffs 2024: 98.0% of GTL's (Tyler Ladd)EP qualifying best at Runoffs 2015: 94.2% of GTL's (Kip Van Steenburg)EP qualifying best at Runoffs 2016: 98.4% of GTL's (Michael Galati)EP qualifying best at Runoffs 2017: 99.3% of GTL's (Matt Reynolds)EP qualifying best at Runoffs 2018: 98.1% of GTL's (Glen McCready)EP qualifying best at Runoffs 2019: 95.3% of GTL's (Jesse Prather)EP qualifying best at Runoffs 2020: 97.0% of GTL's (Jesse Prather)EP qualifying best at Runoffs 2021: 96.7% of GTL's (Jesse Prather)EP qualifying best at Runoffs 2022: 95.7% of GTL's (Jesse Prather)EP qualifying best at Runoffs 2023: 95.1% of GTL's (John Hainsworth)EP qualifying best at Runoffs 2024: 97.3% of GTL's (Tyler Ladd)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
GTLFBFVEPsolid race · dashed qualifying · each class's best lap as a share of GTL's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker
EventGTLFBFVEP
Qual best Race best Trap Qual best Race best Trap vs GTL % of GTL Qual best Race best Trap vs GTL % of GTL Qual best Race best Trap vs GTL % of GTL 
Road America Runoffs 20262026-09-282:46.536Zachary Whitston · fastest of 37 · top 5 within 1.7s+2.435s (+1.48%)2:45.272Brian Farnham · fastest of 34 · top 5 within 1.3s-1.464s (-0.88%)117.4Rick Shields+0.2 mph (+0.1%)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%)
22 rule changes (GTL: 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. · GT3U class removed from GCR; GT3U cars now compete in STU. · 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.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.
  • GTL Remove GT3U from GCR as it is now in STU #39862cars addedremovedcars addedGT3U class removed from GCR; GT3U cars now compete in STU.
  • 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.
Road America Runoffs 20252025-09-292:44.101Andrew Abbott · fastest of 34 · top 5 within 1.3s+1.458s (+0.90%)2:46.736Zachary Whitston · fastest of 29 · top 5 within 0.6s+1.902s (+1.15%)117.2Zachary Whitston+0.7 mph (+0.6%)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%)
17 rule changes (GTL: 3, EP: 14)6 weight · 4 induction · 3 engine · 1 cars added · 2 wording · 1 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. · 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. · TA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof height limit. · EP Triumph GT6 switches to three Weber 40 DCOE carburetors with 28mm chokes, weight rises to 1990 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. · GTL Toyota G16E-GTS removes direct injection prohibition, allowing direct injection engines. · GTL L16 limited prep gains 32mm choke option at 1910 lbs, compression capped 12.0:1, valve lift .450 max.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.
  • 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.
  • GTL Correct language regarding OEM Areo Devices #37137wordingwordingTA2 rear wing height rule clarified: OEM aerodynamic devices exempt from peak-of-roof height limit.
  • EP Triumph GT6 Adjustments #37112inductionfasterinductionEP Triumph GT6 switches to three Weber 40 DCOE carburetors with 28mm chokes, weight rises to 1990 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.
  • GTL G16E-GTS Fuel Injection Spec Line Change #36588engineaddedengineGTL Toyota G16E-GTS removes direct injection prohibition, allowing direct injection engines.
  • GTL GTL Alternate Weight and Choke Option for L16 engine #36653engineaddedengineGTL L16 limited prep gains 32mm choke option at 1910 lbs, compression capped 12.0:1, valve lift .450 max.
Road America Runoffs 20242024-10-012:30.858Peter Shadowen · fastest of 14 · top 5 within 4.4s-1.085s (-0.71%)2:30.844Chris Bovis · fastest of 13 · top 5 within 3.7s-0.757s (-0.50%)133.3Peter Shadowen+1.8 mph (+1.4%)2:42.643Andrew Whitston · fastest of 27 · top 5 within 2.3s-1.351s (-0.82%)2:44.834Andrew Abbott · fastest of 27 · top 5 within 0.9s-0.982s (-0.59%)116.5Brian Farnham-0.7 mph (-0.6%)+13.990squal +11.785s109.3%qual 107.8%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%)-2.975squal -4.055s98.0%qual 97.3%
32 rule changes (GTL: 16, FV: 2, EP: 14)10 weight · 8 cars added · 3 engine · 2 induction · 1 aero · 1 removed · 6 wording · 1 other · FV ferrous rotor must not be cross-drilled; pad cleaning grooves limit unchanged at three per side. · GTL adds Toyota GR86 2021–2023, 2dr RWD, 101.3 in wheelbase. · GTL adds Spec Miata 1990–2005 with legal Spec Miata engine and intake system. · GTL adds Mazda MX5 RF 2017- model with 91.0 in wheelbase. · HP Volkswagen Golf and Jetta 85-92 track correction: front 1537 mm (60.5 in.), rear 1529 mm (60.2 in.). · GTL added to GT3 choke option line in GCR 9.1.2.E.13.n. · 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. · GT2-ST Acura NSX minimum weight rises to 3000 lbs, restrictor increases to 45mm TIR. · GTL Datsun 510 Limited Prep fuel induction increased to 34 mm chokes, minimum weight rises to 2000 lbs. · 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. · GT1-GTX rear blade spoiler: angle 50–75°, max 59.0 wide by 5.0 high inches; total area limit removed. · GT1, GT2, GT3, GTL, GTX Direct Injection now permitted if original equipment. · GT2 Nissan and GT3 Mazda, Mitsubishi 4G93, Nissan QR25DE/DD, QE25DE/DD now permit Direct Injection per 9.1.2.F.7.5.E. · 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. · GTL 12A rotary engines may machine and use 13B housing to O.E. 12A spec across all port types. · GTL Toyota DR86 2021–2024 added to class. · GTL BMW Mini model years changed to 2002-2013. · 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. · FV front wheel bearings wording clarified; specification unchanged. · GTL small unrestricted engines under 1399cc lose 38–79 lbs across Alfa, AMC, Triumph, Mini, Sprite, Fiat, Ford, Honda, Mazda, Nissan, Subaru, Toyota, Volkswagen. · GTL Honda Fit 2009-13 2-door FWD added with 99.0 in wheelbase, alternate 94.0 and 97.0 in. · GTL spec lines moved contiguous with GT2 and GT3; GTA category and specs renumbered behind GTL; P2 engine tables reorganised with restrictor and weight specifications clarified. · GTL Nissan Sentra/200SX A 1400 minimum weight reduced to 1800 lbs.showhide
  • FV Disc Brakes #36822wordingwordingFV ferrous rotor must not be cross-drilled; pad cleaning grooves limit unchanged at three per side.
  • GTL Request to Include Toyota GR86 in GTL #36324cars addedaddedGTL adds Toyota GR86 2021–2023, 2dr RWD, 101.3 in wheelbase.
  • GTL Inclusion of Modified Spec Miata for GTL competition #36325cars addedaddedGTL adds Spec Miata 1990–2005 with legal Spec Miata engine and intake system.
  • GTL Include Mazda MX5 RF 2017- in GTL #36428cars addedaddedGTL adds Mazda MX5 RF 2017- model with 91.0 in wheelbase.
  • 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.).
  • GTL Add GTL to GT3 choke option line. #36236otheraddedGTL added to GT3 choke option line in GCR 9.1.2.E.13.n.
  • 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.
  • GTL Request for Spec Line 1010 Reconsideration #35009weight +300 lbsslowerweightGT2-ST Acura NSX minimum weight rises to 3000 lbs, restrictor increases to 45mm TIR.
  • GTL Allow 34 mm chokes for the Datsun 510 #35661induction +50 lbsfasterinductionGTL Datsun 510 Limited Prep fuel induction increased to 34 mm chokes, minimum weight rises to 2000 lbs.
  • 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.
  • GTL Rear Blade Spoiler Clarification #35261aeroaeroGT1-GTX rear blade spoiler: angle 50–75°, max 59.0 wide by 5.0 high inches; total area limit removed.
  • GTL GT Direct Injection allowance and rules #35437engineaddedengineGT1, GT2, GT3, GTL, GTX Direct Injection now permitted if original equipment.
  • GTL GT2/3 remove Direction Injection not allowed in Spec line notes #35439engineaddedengineGT2 Nissan and GT3 Mazda, Mitsubishi 4G93, Nissan QR25DE/DD, QE25DE/DD now permit Direct Injection per 9.1.2.F.7.5.E.
  • 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.
  • GTL Rotary Engine 12A Rotor Housings #35131engineaddedengineGTL 12A rotary engines may machine and use 13B housing to O.E. 12A spec across all port types.
  • GTL Request to Include Toyota GR86 in GTL #35198cars addedaddedGTL Toyota DR86 2021–2024 added to class.
  • GTL Errors and Omissions, GTL engines & Cars #35226wordingwordingGTL BMW Mini model years changed to 2002-2013.
  • 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.
  • FV FV Wheel Bearing Clarification #35150wordingwordingFV front wheel bearings wording clarified; specification unchanged.
  • GTL Small Engines in GT Lite #34842weightfasterweightGTL small unrestricted engines under 1399cc lose 38–79 lbs across Alfa, AMC, Triumph, Mini, Sprite, Fiat, Ford, Honda, Mazda, Nissan, Subaru, Toyota, Volkswagen.
  • GTL Request to Classify Honda Fit body in GTL #35020cars addedaddedGTL Honda Fit 2009-13 2-door FWD added with 99.0 in wheelbase, alternate 94.0 and 97.0 in.
  • GTL Errors in GTCS Headings and Use of the Terms Category and ClassChange existing GTL and GTA Rules #34453wordingwordingGTL spec lines moved contiguous with GT2 and GT3; GTA category and specs renumbered behind GTL; P2 engine tables reorganised with restrictor and weight specifications clarified.
  • GTL Weight for Nissan Sentra/200SX A 1400's #34918weight -50 lbsfasterweightGTL Nissan Sentra/200SX A 1400 minimum weight reduced to 1800 lbs.
Virginia International Raceway Runoffs 20232023-09-232:09.564Peter Shadowen · fastest of 11 · top 5 within 4.9s+1.775s (+1.39%)2:11.277Graham Fuller · fastest of 10 · top 5 within 2.4s-9.903s (-7.01%)142.7Peter Shadowen+6.7 mph (+4.9%)2:15.639Andrew Whitston · fastest of 27 · top 5 within 1.4s+0.523s (+0.39%)2:16.611Andrew Abbott · fastest of 23 · top 5 within 1.6s-1.482s (-1.07%)115.6Brian Farnham-0.2 mph (-0.2%)+5.334squal +6.075s104.1%qual 104.7%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%)-7.227squal -6.349s94.5%qual 95.1%
20 rule changes (GTL: 7, EP: 13)6 cars added · 3 engine · 2 weight · 1 induction · 1 removed · 1 suspension & brakes · 4 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. · Fields Cardinal V8 added to GT1 with Ford V8 engine, 4.9L, 2100 lbs, fuel injection. · EP BMW Z3 2.5L flat plate intake restrictor reduced from 58mm to 56mm, both throttle bodies. · GTL 3K, 4K, 5K Toyota engines may now use 4Y block only. · 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. · GT2 and GTL add Toyota 4A-F and 4A-FE 1.6L DOHC 16V engines as permitted options. · GTL Fiat X1/9 1500 Limited Prep minimum weight increases to 2000 lbs from 1835 lbs. · GT2 TA2 and GTA throttle body part numbers updated to GM 12570790 or Edelbrock 33869/3870. · GTL adds Ford Festiva 1988-1993 FWD hatchback with Mazda B3 1324cc engine. · GTL adds Toyota G16E-GTS 1618cc DOHC 3-cyl engine, 1945 lbs, SIR, no turbo or direct injection.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.
  • GTL Please classify Fields Cardinal V8 #33784cars addedaddedFields Cardinal V8 added to GT1 with Ford V8 engine, 4.9L, 2100 lbs, fuel injection.
  • EP Investigate Parity of Z3 #33343inductionslowerinductionEP BMW Z3 2.5L flat plate intake restrictor reduced from 58mm to 56mm, both throttle bodies.
  • GTL Toyota 4Y Engine Classification Request #33562engineaddedengineGTL 3K, 4K, 5K Toyota engines may now use 4Y block only.
  • 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.
  • GTL Toyota 4A-F and 4A-FE 1.6L DOHC 16V Engine Request #33415cars addedaddedGT2 and GTL add Toyota 4A-F and 4A-FE 1.6L DOHC 16V engines as permitted options.
  • GTL Fiat HP Limited Prep X1/9 Weight in GTL #33297weightslowerweightGTL Fiat X1/9 1500 Limited Prep minimum weight increases to 2000 lbs from 1835 lbs.
  • GTL GT2 (TA2)/GTA Part Number Update #33315wordingwordingGT2 TA2 and GTA throttle body part numbers updated to GM 12570790 or Edelbrock 33869/3870.
  • GTL Request to add Ford Festiva to GTL #33335cars addedaddedGTL adds Ford Festiva 1988-1993 FWD hatchback with Mazda B3 1324cc engine.
  • GTL Engine Request #33064cars addedaddedGTL adds Toyota G16E-GTS 1618cc DOHC 3-cyl engine, 1945 lbs, SIR, no turbo or direct injection.
Virginia International Raceway Runoffs 20222022-09-242:07.789Peter Shadowen · fastest of 14 · top 5 within 2.2s+0.792s (+0.62%)2:21.180Michael Lewis · fastest of 13 · top 5 within 2.1s+13.343s (+10.44%)136.0Peter Shadowen+4.9 mph (+3.7%)2:15.116Brian Farnham · fastest of 29 · top 5 within 1.1s-0.596s (-0.44%)2:18.093Andrew Whitston · fastest of 28 · top 5 within 1.2s-0.196s (-0.14%)115.8Jonathan Weisheit+1.1 mph (+0.9%)-3.087squal +7.327s97.8%qual 105.7%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%)+9.675squal -5.463s106.9%qual 95.7%
28 rule changes (GTL: 3, FV: 4, EP: 21)6 engine · 5 cars added · 3 induction · 3 weight · 1 aero · 1 suspension & brakes · 1 tyres & wheels · 7 wording · 1 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. · GT1, GT2, GT3, GTL, GTX tail lights may now be original style or custom panel graphic with functioning red LED brake lamps. · 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. · 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. · 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. · FV connecting rod options expanded to include BrianCrower part BC6417 and Newland Group part 4M113077. · FV connecting rods minimum weight 425.0 grams, center-to-center length 130 +0.10/-0.25 mm; Crower, BrianCrower, Newland Group parts allowed if meeting specs. · Ginetta G40 added to GTL with Ford Zetec 1796cc engine, 2050 lbs minimum weight, 22.5mm SIR. · 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. · 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. · FV Crower connecting rods SP93280B and BC6417 allowed as direct replacement, must meet OEM minimum weight. · 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. · FV allows Crower SP93280B and Brian Crower Racing Rods connecting rods as direct replacements, matching OEM minimum weight. · 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. · GT3 Volkswagen Fun Cup Beetle EVO3 classified, sealed SOHC 1984cc engine, 2060 lbs minimum weight.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.
  • GTL Tail lights on all GT category race cars. #32799wordingwordingGT1, GT2, GT3, GTL, GTX tail lights may now be original style or custom panel graphic with functioning red LED brake lamps.
  • 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.
  • 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.
  • 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.
  • FV Connecting Rod Update Request for 9.1.1.C Formula Vee (FV) 5.C.6 #32160engineaddedengineFV connecting rod options expanded to include BrianCrower part BC6417 and Newland Group part 4M113077.
  • FV E&O clarification of connecting rod center-to-center length #32183wordingwordingFV connecting rods minimum weight 425.0 grams, center-to-center length 130 +0.10/-0.25 mm; Crower, BrianCrower, Newland Group parts allowed if meeting specs.
  • GTL Request to Classify Ginetta G40 in GTL #31599cars addedaddedGinetta G40 added to GTL with Ford Zetec 1796cc engine, 2050 lbs minimum weight, 22.5mm SIR.
  • 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.
  • 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.
  • FV Update direct replacement connecting rod information #31843wordingwordingFV Crower connecting rods SP93280B and BC6417 allowed as direct replacement, must meet OEM minimum weight.
  • 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.
  • FV Formula V Connecting Rod Replacement #31448engineaddedengineFV allows Crower SP93280B and Brian Crower Racing Rods connecting rods as direct replacements, matching OEM minimum weight.
  • 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.
  • GTL Request car classification #31032cars addedaddedGT3 Volkswagen Fun Cup Beetle EVO3 classified, sealed SOHC 1984cc engine, 2060 lbs minimum weight.
Indianapolis Motor Speedway Runoffs 20212021-09-251:51.819Christopher Bovis · fastest of 22 · top 5 within 1.8s+1.488s (+1.35%)1:51.952Scott Twomey · fastest of 19 · top 5 within 1.7s-0.116s (-0.10%)129.5Brian Linn1:57.479Andrew Whitston · fastest of 48 · top 5 within 0.8s+1.720s (+1.49%)1:57.234Alex Scaler · fastest of 47 · top 5 within 1.0s+1.311s (+1.13%)124.0Mark Edwards+5.282squal +5.660s104.7%qual 105.1%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-2.024squal -3.638s98.2%qual 96.7%
22 rule changes (GTL: 8, EP: 14)8 cars added · 4 weight · 3 induction · 1 aero · 3 wording · 3 other · 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. · GTA part numbers updated: 0-80541-1 to 0-80541-2 in two locations and 6010 to 6014X in TA2 Appendix. · 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. · GTL Honda B18 split into B18A/B at 1797 cc 2050 lbs and B18C at 1834 cc 2065 lbs. · GTL Nissan B13 Sentra may have hood bulge maximum 1.5 inches high by 10.0 long by 6.0 wide. · unclear · 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. · 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. · GTL Mazda 12A SIR increases to 29mm, minimum weight rises to 2000 lbs, 28mm SIR option with 175 lb penalty removed. · GTL adds FIAT X-1/9 Bertone 1500 SOHC, 1498 cc, 2000 lbs, fuel injection or carburetors permitted. · EP Austin-Healey 3000 gains option to use TR-6 front calipers and discs as alternate. · GTL Nissan MRA8DE 1.8L engine added, 1797 cc, DOHC, 2050 lbs minimum weight. · GTL Mazda 13B SIR increases from 26 mm to 28 mm; 27 mm option with 175 lbs removed. · 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.showhide
  • 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.
  • GTL Request to Update GTA Obsolete Part Numbers #30615wordingwordingGTA part numbers updated: 0-80541-1 to 0-80541-2 in two locations and 6010 to 6014X in TA2 Appendix.
  • 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.
  • GTL Request clarification for the Honda B18a,bVS B18c #30482cars addedaddedGTL Honda B18 split into B18A/B at 1797 cc 2050 lbs and B18C at 1834 cc 2065 lbs.
  • GTL Request to Allow Hood Bulge on Nissan B13 Sentra #30504aeroaddedaeroGTL Nissan B13 Sentra may have hood bulge maximum 1.5 inches high by 10.0 long by 6.0 wide.
  • GTL Request BMW E21 Classing #30582otherunclearunclear
  • 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.
  • 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.
  • GTL Request for Help for Mazda 12A #29754induction +50 lbsslowerinductionGTL Mazda 12A SIR increases to 29mm, minimum weight rises to 2000 lbs, 28mm SIR option with 175 lb penalty removed.
  • GTL Request LP HP Fiat X1/9 & Bertone 1500 to GTL #30058cars addedaddedGTL adds FIAT X-1/9 Bertone 1500 SOHC, 1498 cc, 2000 lbs, fuel injection or carburetors permitted.
  • 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.
  • GTL Please Add GTL Nissan 1.8L Engine MRA8DE #29805cars addedaddedGTL Nissan MRA8DE 1.8L engine added, 1797 cc, DOHC, 2050 lbs minimum weight.
  • GTL Increase 13b SIR size #29867inductionfasterinductionGTL Mazda 13B SIR increases from 26 mm to 28 mm; 27 mm option with 175 lbs removed.
  • 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.
Road America Runoffs 20202020-10-022:31.943Chris Bovis · fastest of 14 · top 5 within 6.3s2:31.601Peter Shadowen · fastest of 14 · top 5 within 7.2s131.4Peter Shadowen2:43.994Hunter Phelps-Barron · fastest of 28 · top 5 within 0.6s2:45.816Alex Scaler · fastest of 24 · top 5 within 1.5s117.1Hunter Phelps-Barron+14.215squal +12.051s109.4%qual 107.9%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-2.554squal -4.621s98.3%qual 97.0%
37 rule changes (GTL: 17, FV: 6, EP: 14)6 cars added · 5 tyres & wheels · 4 aero · 3 engine · 3 induction · 2 weight · 1 suspension & brakes · 11 wording · 2 other · HP 84-87 Toyota Corolla wheel diameter increases from 13 to 15 inches. · GT1/GT2/GT3/GTL/GTX turbocharging and supercharging now permitted if listed on spec line. · EP BMW Z3 2.5L cylinder head casting 1738400 permitted with iron block castings 1748933 or 1738566. · GTL Mazda 13B restrictor increases from 24mm to 26mm SIR, minimum weight rises to 2125 lbs, alternative 27mm SIR option adds 175 lbs. · Porsche 911 S 67-68 classified in EP at 1800–1890 lbs, 1991cc opposed 6-cylinder SOHC with 36mm carburetors. · FV now permits 4 bolt wheels in addition to existing specifications. · FV now allows 4-bolt pattern wheels in addition to existing specifications. · GTL: Toyota MR2 Spyder 1999–2007 newly classified for GTL competition. · TA2 Gurney flap wording clarified: replace 'wicker bill' and 'wicker' with 'Gurney flap' throughout wing specifications. · STO rear wing rules clarify that wicker is called Gurney flap in two places; no performance change. · GT Gurney flap wording clarified: wickerbill and tab terminology replaced with Gurney flap throughout sections 9.1.2.F.7.b. · GTL Mazda 13B restrictor size addressed in response to letter 28518; see that letter for details. · EP BMW 2.8L, 328i E36/E46, and 325i E36 now require iron blocks only; 325i E46 aluminum block removed. · GTL SIR stall test procedure clarified: system tested as raced, competitor must prevent air bypass behind 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. · GTL wing mount openings excluded from square inch area limit. · EP Caterham 7 America engine limited to IT prep with specific sections, comp ratio 10.0:1, valve lift .380 inch. · 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. · FV rain tyre changes to Hoosier #44266 22.5 x 5.0 x 15 WET or W3. · GTL wing mounting posts limited to 85 square inches exposed area each, measured flat from side view. · GTL wing mounting posts limited to 85 square inches each, measured flat from side view. · GTL wing endplates maximum area increased to 64 square inches from 8.5 by 3.0 inches rectangle. · GTL Mazda 12A street port minimum weight drops to 1950 lbs. · HP Datsun 1200 carburetor option changes from 26mm to 30mm choke(s) in 40 DCN, DCNF, IDF. · GT1, GT2, GT3, GTL, GTX may use bonded-glass factory windshields without clips or straps if attached per original specifications. · Mazda Miata models EP and FP throttle body specified 55mm, brake rotor thickness figures removed. · FV allows non-spec Hoosier tyres at Regional races only; Majors, Super Tour, and Runoffs require spec tyres from 1/1/2020. · Formula Vee now allows 22.5 x 5.5 x 15 rear tires on front axle; rain tire mandated as Hoosier #44266 22.5 x 5.0 x 15 from 1/1/2020. · GTX Misc. adds Factory Five Type 65 Coupe R Ford 302/351 and 5.0/5.2L NA at 2600 lbs, plus Ferrari 458/488 Challenge, Ford FP350S, Chevrolet C6, Lamborghini Super Trofeo. · GTL adds Jetta Mk1 two-door classification effective 2020-01-01. · EP, FP, HP cylinder head rules reorganized for clarity; no performance change. · FV wheels may now be 15-inch 4.5J steel VW with same 5-bolt pattern as standard 4J, within track limits. · GTL Honda CRX 84-87 and 88-91 lose permission to use IRS with 2.5% weight penalty.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.
  • GTL GT Category Wording #29193wordingaddedGT1/GT2/GT3/GTL/GTX turbocharging and supercharging now permitted if listed on spec line.
  • EP EP BMW Z3 Rule Clarification #28998wordingwordingEP BMW Z3 2.5L cylinder head casting 1738400 permitted with iron block castings 1748933 or 1738566.
  • GTL Request to change the Mazda 13b restrictor size #28518induction +175 lbsfasterinductionGTL Mazda 13B restrictor increases from 24mm to 26mm SIR, minimum weight rises to 2125 lbs, alternative 27mm SIR option adds 175 lbs.
  • 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.
  • FV Support for Recommended Item - 4 bolt wheels in FV #29084cars addedaddedFV now permits 4 bolt wheels in addition to existing specifications.
  • FV Support for 4-bolt pattern wheels #28955 #29118tyres & wheelsaddedtyres & wheelsFV now allows 4-bolt pattern wheels in addition to existing specifications.
  • GTL Request to classify 1999-2007 Toyota MR2 Spyder body #28870cars addedaddedGTL: Toyota MR2 Spyder 1999–2007 newly classified for GTL competition.
  • GTL TA2 Gurney flap wicker clarification #28874wordingwordingTA2 Gurney flap wording clarified: replace 'wicker bill' and 'wicker' with 'Gurney flap' throughout wing specifications.
  • GTL STO Gurney flap wicker clarification #28883wordingwordingSTO rear wing rules clarify that wicker is called Gurney flap in two places; no performance change.
  • GTL GT Gurney flap wicker clarification #28909wordingwordingGT Gurney flap wording clarified: wickerbill and tab terminology replaced with Gurney flap throughout sections 9.1.2.F.7.b.
  • GTL Mazda 13b Restrictor Size Follow up to Letter 28518 #29015wordingunclearGTL Mazda 13B restrictor size addressed in response to letter 28518; see that letter for details.
  • 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.
  • GTL Stall Test #28709wordingwordingGTL SIR stall test procedure clarified: system tested as raced, competitor must prevent air bypass behind 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.
  • GTL GTL Wing Rule #28754aeroaddedaeroGTL wing mount openings excluded from square inch area limit.
  • 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.
  • 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.
  • FV Update rain tire designation #28444tyres & wheelstyres & wheelsFV rain tyre changes to Hoosier #44266 22.5 x 5.0 x 15 WET or W3.
  • GTL Wing Mounting Upright Size #27641aeroaeroGTL wing mounting posts limited to 85 square inches exposed area each, measured flat from side view.
  • GTL Wing Mounting Upright Size #27641aeroaeroGTL wing mounting posts limited to 85 square inches each, measured flat from side view.
  • GTL GTL wing end plates addition #28243aerofasteraeroGTL wing endplates maximum area increased to 64 square inches from 8.5 by 3.0 inches rectangle.
  • GTL Clarification to letter #27406 #28309weight -50 lbsfasterweightGTL Mazda 12A street port minimum weight drops to 1950 lbs.
  • EP Request for Help for Datsun 1200 #27934inductionfasterinductionHP Datsun 1200 carburetor option changes from 26mm to 30mm choke(s) in 40 DCN, DCNF, IDF.
  • GTL Windshield Clips #27323otheraddedGT1, GT2, GT3, GTL, GTX may use bonded-glass factory windshields without clips or straps if attached per original specifications.
  • EP Request to List Mazda Miata Throttle Body Size #27907wordingwordingMazda Miata models EP and FP throttle body specified 55mm, brake rotor thickness figures removed.
  • FV FV Allow non-spec tire in Regional competition #26284tyres & wheelsaddedtyres & wheelsFV allows non-spec Hoosier tyres at Regional races only; Majors, Super Tour, and Runoffs require spec tyres from 1/1/2020.
  • FV Request to Allow Rear Tires on the Front of Formula Vee #26537tyres & wheelsaddedtyres & wheelsFormula Vee now allows 22.5 x 5.5 x 15 rear tires on front axle; rain tire mandated as Hoosier #44266 22.5 x 5.0 x 15 from 1/1/2020.
  • GTL Request Factory Five Daytona coupe classification #26308cars addedaddedGTX Misc. adds Factory Five Type 65 Coupe R Ford 302/351 and 5.0/5.2L NA at 2600 lbs, plus Ferrari 458/488 Challenge, Ford FP350S, Chevrolet C6, Lamborghini Super Trofeo.
  • GTL Request to Classify the MK1 two door Jetta #27648cars addedaddedGTL adds Jetta Mk1 two-door classification effective 2020-01-01.
  • EP Re-organize Prep2 Cylinder Head Rules for Clarity & Consistency #27661wordingwordingEP, FP, HP cylinder head rules reorganized for clarity; no performance change.
  • FV Clarification on Wheel Bolt Pattern #27603tyres & wheelsaddedtyres & wheelsFV wheels may now be 15-inch 4.5J steel VW with same 5-bolt pattern as standard 4J, within track limits.
  • GTL 88-91 Honda CRX Spec Line Correction #27233suspension & brakesremovedsuspension & brakesGTL Honda CRX 84-87 and 88-91 lose permission to use IRS with 2.5% weight penalty.
Virginia International Raceway Runoffs 20192019-10-052:06.997Peter Shadowen · fastest of 19 · top 5 within 4.0s2:07.837Bill Ball · fastest of 18 · top 5 within 4.2s131.1Peter Shadowen1:54.469Pete Frost · only car1:57.688Pete Frost · only car145.9Pete Frost-10.149squal -12.528s92.1%qual 90.1%2:15.712Andrew Whitston · fastest of 26 · top 5 within 1.5s2:18.289Zachary Whitston · fastest of 19 · top 5 within 0.4s114.8Roger Siebenaler+10.452squal +8.715s108.2%qual 106.9%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-6.206squal -6.010s95.1%qual 95.3%
29 rule changes (GTL: 13, FV: 6, EP: 10)6 cars added · 3 engine · 3 weight · 2 aero · 2 induction · 1 removed · 1 suspension & brakes · 1 tyres & wheels · 9 wording · 1 other · FV exhaust exit opening repositioned: minimum one inch, maximum four inches behind rear body. · 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. · FV allows fifteen-inch steel wheels at 4J or 4.5J width, standard VW sedan or within track dimensions. · GTL Fun Cup Beetle engine weight set to 1850 lbs with Weber DMTL 32/34 induction. · EP Mazda MX-5/Miata model years expand from 1999-2002 to 1999-2005. · GTL Fun Cup Beetle removes reference to VW engine table; Fun Cup engines only permitted. · GTL Honda CRZ 10-14, CRZ 15-16, and Insight 00-06 gain alternate wheelbase option of 90.6 inches. · FV exhaust outlet opening max distance from body rear increased from 3 to 4 inches. · EP Mazda RX-8 firewall may be modified for 13B engine fitment and must be sealed. · FV front track maximum 52.500 inches; rear track 49.125–50.750 inches; spacers now allowed. · GTL Fun Cup Beetle added, all model years, 2-door RWD, 94.5 in wheelbase, VW Fun Cup spec chassis. · GTX tube frame cars now allowed fuel injection with maximum 90mm throttle body. · GTX adds Ligier JS2 R classification with restrictor and minimum weight. · GTL Mazda 13B may use 25mm SIR with 175 lbs weight penalty added. · 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. · FV disc brake assembly minimum weight clarified to 16.5 lbs total; caliper minimum weight requirement of 1.65 lbs removed. · GT1 and GT2/3/Lite remove ride height ground clearance rules; cars may now touch ground when tires deflate. · 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. · GTL Mazda 12A may use 28mm SIR plus 175 lbs. · GTL: Ford Mustang 94-04 body newly classified for GTL racing. · FV intake manifold horizontal tube measurement location clarified; removed specific distance ranges from rule text. · GTL Mini 1275–1399 Iron and Aluminum Crossflow with OE common sump gearbox reduce weight by 125 lbs, up from 50 lbs. · GTL BMC thru Rover Group removes four long inactive Mini engines: 948, 970, 1071, 1098. · GTX FIA GT3: Audi R8 now 40 mm restrictor and 2900 lbs; BMW Z4 now 70 mm restrictor and 2800 lbs; Ferrari 488 now 35 mm restrictor, TIR, and 3025 lbs.showhide
  • FV Allowed Modifications E&O #27398wordingwordingFV exhaust exit opening repositioned: minimum one inch, maximum four inches behind rear body.
  • 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.
  • FV E&O Wheels #27230tyres & wheelsaddedtyres & wheelsFV allows fifteen-inch steel wheels at 4J or 4.5J width, standard VW sedan or within track dimensions.
  • GTL Fun Cup Beetle #27334wordingwordingGTL Fun Cup Beetle engine weight set to 1850 lbs with Weber DMTL 32/34 induction.
  • EP Request Miata Eligibility - 2003 #27121cars addedaddedEP Mazda MX-5/Miata model years expand from 1999-2002 to 1999-2005.
  • GTL GTL #26960wordingwordingGTL Fun Cup Beetle removes reference to VW engine table; Fun Cup engines only permitted.
  • GTL Request CRZ wheelbase change #26896cars addedaddedGTL Honda CRZ 10-14, CRZ 15-16, and Insight 00-06 gain alternate wheelbase option of 90.6 inches.
  • FV Exhaust termination rule E&O #26702wordingwordingFV exhaust outlet opening max distance from body rear increased from 3 to 4 inches.
  • 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.
  • FV E&O Dimensions #26674suspension & brakessuspension & brakesFV front track maximum 52.500 inches; rear track 49.125–50.750 inches; spacers now allowed.
  • GTL Request to Classify VW Fun Cup Beetle #25986cars addedaddedGTL Fun Cup Beetle added, all model years, 2-door RWD, 94.5 in wheelbase, VW Fun Cup spec chassis.
  • GTL Request GTX Fuel injection for previous GT-1 tube frame cars #26141engineaddedengineGTX tube frame cars now allowed fuel injection with maximum 90mm throttle body.
  • GTL Request to Classify Ligier JS2 R #26535cars addedaddedGTX adds Ligier JS2 R classification with restrictor and minimum weight.
  • GTL Request for GTL Mazda 13B SIR Increase with Penalty #26572engineaddedengineGTL Mazda 13B may use 25mm SIR with 175 lbs weight penalty added.
  • 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.
  • FV Request to clarify Disc Brake rules bearing retainer & weights #26262weightslowerweightFV disc brake assembly minimum weight clarified to 16.5 lbs total; caliper minimum weight requirement of 1.65 lbs removed.
  • GTL Request Ride Height Clarification #26600wordingfasterGT1 and GT2/3/Lite remove ride height ground clearance rules; cars may now touch ground when tires deflate.
  • 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.
  • GTL Request Mazda 12a Rotary SIR Increase #26081inductionaddedinductionGTL Mazda 12A may use 28mm SIR plus 175 lbs.
  • GTL Request to Classify Mustang 2 Body in GTL #26222cars addedaddedGTL: Ford Mustang 94-04 body newly classified for GTL racing.
  • FV FV Intake Manifold Clarification #26008wordingwordingFV intake manifold horizontal tube measurement location clarified; removed specific distance ranges from rule text.
  • GTL Request for GTL Mini Adjustments #25754weightfasterweightGTL Mini 1275–1399 Iron and Aluminum Crossflow with OE common sump gearbox reduce weight by 125 lbs, up from 50 lbs.
  • GTL BMC thru Rover Group remove long inactive mini #25771removedremovedGTL BMC thru Rover Group removes four long inactive Mini engines: 948, 970, 1071, 1098.
  • GTL GTX Homologation table update #26034otherunclearGTX FIA GT3: Audi R8 now 40 mm restrictor and 2900 lbs; BMW Z4 now 70 mm restrictor and 2800 lbs; Ferrari 488 now 35 mm restrictor, TIR, and 3025 lbs.
Sonoma Raceway Runoffs 20182018-10-101:47.885Troy Ermish · fastest of 20 · top 5 within 4.5s1:49.458Troy Ermish · fastest of 19 · top 5 within 3.6s109.3Charles Leonard1:28.612J 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-18.269squal -19.273s83.3%qual 82.1%1:52.637Skip Streets · fastest of 29 · top 5 within 1.6s1:53.639Alex Scaler · fastest of 28 · top 5 within 0.4s106.3Skip Streets+4.181squal +4.752s103.8%qual 104.4%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-2.940squal -2.057s97.3%qual 98.1%
No rule changes on record between these events
Indianapolis Motor Speedway Runoffs 20172017-09-251:50.331Christopher Bovis · fastest of 26 · top 5 within 1.5s1:52.068Christopher Bovis · fastest of 20 · top 5 within 1.0s1:33.746Gary Hickman · fastest of 18 · top 5 within 3.3s1:33.702Alex Mayer · fastest of 17 · top 5 within 3.0s-18.366squal -16.585s83.6%qual 85.0%1:55.759Michael Varacins · fastest of 39 · top 5 within 1.0s1:55.923Michael Varacins · fastest of 32 · top 5 within 1.3s+3.855squal +5.428s103.4%qual 104.9%1:49.597Matt Reynolds · fastest of 44 · top 5 within 1.2s1:50.396Matt Reynolds · fastest of 45 · top 5 within 0.5s-1.672squal -0.734s98.5%qual 99.3%
No rule changes on record between these events
Mid-Ohio Sports Car Course Runoffs 20162016-09-191:35.377Wilson Wright · fastest of 28 · top 5 within 1.2s1:35.912Kyle Disque · fastest of 28 · top 5 within 1.1s1:19.886Alex Mayer · fastest of 10 · top 5 within 1.5s1:21.015Jeremy Hill · fastest of 10 · top 5 within 1.2s-14.897squal -15.491s84.5%qual 83.8%1:37.942Alex Scaler · fastest of 41 · top 5 within 0.3s1:38.066Flinn Lazier · fastest of 38 · top 5 within 0.7s+2.154squal +2.565s102.2%qual 102.7%1:33.847Michael Galati · fastest of 25 · top 5 within 0.8s1:34.266Michael Galati · fastest of 23 · top 5 within 1.3s-1.646squal -1.530s98.3%qual 98.4%
No rule changes on record between these events
Daytona International Speedway Runoffs 20152015-09-212:11.387Jim Dentici · fastest of 10 · top 5 within 2.2s2:13.564Jim Dentici · fastest of 9 · top 5 within 2.0s1:50.711J R Osborne · fastest of 20 · top 5 within 1.1s1:51.616J R Osborne · fastest of 19 · top 5 within 2.1s-21.948squal -20.676s83.6%qual 84.3%2:21.167Roger Siebenaler · fastest of 31 · top 5 within 0.8s2:21.142Andrew Whitston · fastest of 30 · top 5 within 1.1s+7.578squal +9.780s105.7%qual 107.4%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-8.455squal -7.593s93.7%qual 94.2%

By track

TrackEvents Typical % of GTL Best Latest 
Road America4100.0%2 of 4 with GTL100.0%Runoffs 2020100.0%Runoffs 2024
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 GTL'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.