Lap times across years say as much about the weather as the class. % of STU is each class's best lap as a share of STU'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.
Closest to the field:STU 100.0% of STU Eric Heinrich, Daytona International Speedway Runoffs 2015 race · FA 71.2% of STU Alex Mayer, Virginia International Raceway Runoffs 2022 race · SM 91.3% of STU Travis Wiley, Virginia International Raceway Runoffs 2022 race
STUFASMsolid race · dashed qualifying · slower is lower
STUFASMsolid race · dashed qualifying · each class's best lap as a share of STU's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker
2:24.912Richard Astacio · fastest of 17 · top 5 within 2.6s+1.829s (+1.28%)
2:26.416Richard Astacio · fastest of 16 · top 5 within 1.5s+1.919s (+1.33%)
145.1Hugh Stewart+0.8 mph (+0.5%)
2:02.513Dudley Fleck · fastest of 9 · top 5 within 6.9s+1.590s (+1.31%)
2:03.334James French · fastest of 10 · top 5 within 1.4s+0.680s (+0.55%)
158.6John McAleer+1.5 mph (+1.0%)
-23.082squal -22.399s
84.2%qual 84.5%
2:42.173Brett Kowalski · fastest of 34 · top 5 within 0.3s-0.938s (-0.58%)
2:42.725Francisco Barroso · fastest of 35 · top 5 within 0.2s-1.705s (-1.04%)
119.6Wyatt Couch+0.3 mph (+0.3%)
+16.309squal +17.261s
111.1%qual 111.9%
24 rule changes (STU: 15, FA: 7, SM: 2)6 cars added · 3 induction · 3 weight · 2 engine · 2 tyres & wheels · 1 aero · 6 wording · 1 other · GT3U wheel and tyre options clarified: 15x7 with 225 section at +275 lbs; 15x9 with 245 section at +275 lbs plus 1.5%; 16–18x9 with 245 section at +275 lbs plus 3.0%. · FA sealed engine teardown: competitors no longer pay reassembly and resealing costs; stewards handle inspection per section 9.3.42. · SM/SMX Mazda rear toe link part number revised from 0000-04-5361426 to 0000-04-5361. · STU cars at or under 2,825 lbs minimum weight limited to 8-inch wheels; over 2,825 lbs limited to 9-inch wheels. · STU GT3U minimum weight increases from GT3 race weight plus 225 to plus 275 pounds; 2.0L unrestricted engines add 75 lbs. · FA Mazda 13B rotary permits one 48mm or 50mm dual-throat carburetor with 41.5mm venturi or fuel injection with 36mm SIR. · STU adds BMW M50B20TU engine, 1991 cc, minimum weight per chart, must meet all STU engine regulations. · STL, STU weight calculation procedure clarified: positive percentages added first, negative subtracted second, then fixed weights applied. · STU Honda K20C1 Turbo I4 turbo restrictor increases from 35mm to 36mm TIR. · STU GT86 Cup car must meet 2022 Toyota GR Cup rules, tires maximum 245 section width. · SM/SMX part number 0000-10-6900 replaced with 0000-06-5016-KT in GCR 9.1.7.C.1.j.1.c. · STU Mazda Renesis Street Port added to Table B with 2450 lbs minimum weight and 70mm throttle body options. · STU eliminates 33 and 34 mm inlet restrictor options, removing minimum weights of 2380 and 2525 lbs. · STU Mazda MZR engines may now use Fab 9 Elite NC MX5 Performance Intake manifold as alternative option. · Pro Formula Mazda allows lower intake manifold unrestricted, throttle body increased to 80mm maximum. · FA MZR may use Noor P/N 0088-8-00 intake with AT Power runners; aluminum spacer minimum length 2.200 inches required. · FA Formula 1000 motorcycle-based 4-cycle engine loses maximum compression ratio 14.5:1 limit; current rules apply. · FA Formula 1000 allows carbon fiber external panels, forward-facing gaps, raises undertray to 125mm, allows eight 75×125mm rub blocks, widens diffuser to 110cm with 75mm radius transitions. · STU Mazda MZR (LF, L3, L5) Turbo added; Goodwin intake removed, Jack Spania Racing 70 mm intake and Fab9 Tuning bottom-mount turbo kit approved. · STU 36mm restrictor revised to 2830 cc, 37mm to 2980 cc. · STU removes 275 tire option and 2% weight adder for cars over 3150 lbs; maximum section width now 245. · STU Honda K20 and K24 engines lose 2% weight penalty; minimum weight now per chart only. · FA class adds USF Pro 2000 car as permitted model. · STU Honda K24 engine swap weight increases by 2 percent, effective November 1, 2025.showhide
STU Wheel and tire requirements for GT3U #40679wordingwordingGT3U wheel and tyre options clarified: 15x7 with 225 section at +275 lbs; 15x9 with 245 section at +275 lbs plus 1.5%; 16–18x9 with 245 section at +275 lbs plus 3.0%.
FA Update sealed engine teardown section #40621wordingaddedFA sealed engine teardown: competitors no longer pay reassembly and resealing costs; stewards handle inspection per section 9.3.42.
SM Rear Toe Link #40271wordingwordingSM/SMX Mazda rear toe link part number revised from 0000-04-5361426 to 0000-04-5361.
STU 9” Wheels #40433tyres & wheelsslowertyres & wheelsSTU cars at or under 2,825 lbs minimum weight limited to 8-inch wheels; over 2,825 lbs limited to 9-inch wheels.
STU Weight adjustment to former GT3U cars #40474weightslowerweightSTU GT3U minimum weight increases from GT3 race weight plus 225 to plus 275 pounds; 2.0L unrestricted engines add 75 lbs.
FA Motor Classification #40175cars addedaddedFA Mazda 13B rotary permits one 48mm or 50mm dual-throat carburetor with 41.5mm venturi or fuel injection with 36mm SIR.
STU Request to allow BMW M50B20TU engine in STU #40202cars addedaddedSTU adds BMW M50B20TU engine, 1991 cc, minimum weight per chart, must meet all STU engine regulations.
STU Calculating Weight #40224wordingwordingSTL, STU weight calculation procedure clarified: positive percentages added first, negative subtracted second, then fixed weights applied.
STU Turbo Restrictor Size Increase Request #40008inductionfasterinductionSTU Honda K20C1 Turbo I4 turbo restrictor increases from 35mm to 36mm TIR.
STU GT86 Cups Car in STU #40028wordingwordingSTU GT86 Cup car must meet 2022 Toyota GR Cup rules, tires maximum 245 section width.
SM Part Number Change Request #39914otherunclearSM/SMX part number 0000-10-6900 replaced with 0000-06-5016-KT in GCR 9.1.7.C.1.j.1.c.
STU Mazda Rx-8 Renesis - Streetported Variant & Added Weight #39785cars addedaddedSTU Mazda Renesis Street Port added to Table B with 2450 lbs minimum weight and 70mm throttle body options.
STU Eliminate 33 and 34 mm TIRs #39872inductionremovedinductionSTU eliminates 33 and 34 mm inlet restrictor options, removing minimum weights of 2380 and 2525 lbs.
STU Fab 9 Racing Intake Manifold in STU #39767cars addedaddedSTU Mazda MZR engines may now use Fab 9 Elite NC MX5 Performance Intake manifold as alternative option.
FA Pro Mazda Classification and Performance Enhancement Proposal #39411enginefasterenginePro Formula Mazda allows lower intake manifold unrestricted, throttle body increased to 80mm maximum.
FA Alternate Intake Manifold for MZR #38223inductionaddedinductionFA MZR may use Noor P/N 0088-8-00 intake with AT Power runners; aluminum spacer minimum length 2.200 inches required.
FA Engine Compression Rule Change Request #39302enginefasterengineFA Formula 1000 motorcycle-based 4-cycle engine loses maximum compression ratio 14.5:1 limit; current rules apply.
FA Change Formula 1000 allowances #39608aerofasteraeroFA Formula 1000 allows carbon fiber external panels, forward-facing gaps, raises undertray to 125mm, allows eight 75×125mm rub blocks, widens diffuser to 110cm with 75mm radius transitions.
STU Request for Permission on Aftermarket Turbo Kit and Intake #39529cars addedaddedSTU Mazda MZR (LF, L3, L5) Turbo added; Goodwin intake removed, Jack Spania Racing 70 mm intake and Fab9 Tuning bottom-mount turbo kit approved.
STU Turbo Inlet Restrictor Table #38961wordingwordingSTU 36mm restrictor revised to 2830 cc, 37mm to 2980 cc.
STU 275 Tire Rule #38983tyres & wheelsslowertyres & wheelsSTU removes 275 tire option and 2% weight adder for cars over 3150 lbs; maximum section width now 245.
STU STU Honda Engine weight penalty #39375weightfasterweightSTU Honda K20 and K24 engines lose 2% weight penalty; minimum weight now per chart only.
FA Re-Consider USF Pro 2000 Car for Formula Atlantic Class #38783cars addedaddedFA class adds USF Pro 2000 car as permitted model.
STU Non-Homologated Engine Swaps - Specifically K24A2 w/ Honda CRZ #38746weightslowerweightSTU Honda K24 engine swap weight increases by 2 percent, effective November 1, 2025.
2:23.083Peter Cunningham · fastest of 16 · top 5 within 2.6s-3.144s (-2.15%)
2:24.497Chip Herr · fastest of 15 · top 5 within 3.8s-1.327s (-0.91%)
144.3Chip Herr-1.0 mph (-0.7%)
2:00.923Hans Peter · fastest of 12 · top 5 within 2.4s-0.637s (-0.52%)
2:02.654Hans Peter · fastest of 11 · top 5 within 3.1s+0.864s (+0.71%)
157.0Shane Kennett-3.0 mph (-1.9%)
-21.843squal -22.160s
84.9%qual 84.5%
2:43.111Bobby Gossett · fastest of 32 · top 5 within 0.3s+2.005s (+1.24%)
2:44.430Kyle Greenhill · fastest of 28 · top 5 within 0.3s+2.944s (+1.82%)
119.3Francisco Barroso-0.6 mph (-0.5%)
+19.933squal +20.028s
113.8%qual 114.0%
25 rule changes (STU: 18, FA: 3, SM: 4)6 weight · 5 cars added · 4 tyres & wheels · 2 engine · 1 induction · 6 wording · 1 other · STU Lotus Elise SC and Exige SC weight reduced from 2450 to 2250 lbs. · STU-TCR gains GT3 TCR spec lines; 275 tyre option now costs 150 lb adder, up from 100 lb. · Lotus Evora GT4 minimum weight drops to 2700 lbs; Elise Cup R to 2250 lbs; Elise SC and Exige SC to 2450–2550 lbs. · FA Ligier JS F3 front tires change to Hoosier 240/580R13 MS, rear to 300/590R13 MS. · STU 2.8–3.2L N/A engines now permit 245 max tyre width; over 3150 lbs cars may run 275 with 2% weight penalty. · STU Mazda MZR intake manifold now allows Goodwin 61-2510 or Gato Performance 31972. · STU Honda JDM H23a added, 2259 cc, minimum weight per chart, must meet ST engine regulations. · SMX drivers must submit data acquisition files on time or face suspension and $250 fine. · SMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fines, level 2 and 4 may carry $500 fines. · SM tire marking rules clarified: one Hoosier SM 7.5 P205/50/ZR17 set per Super Tour weekend, impound after first dry session, damaged tires may be replaced with used tires only. · STU wheels capped at 18 inches diameter; under 2,850 lbs max 8 inches wide, over 2,850 lbs max 9 inches wide. · STU-GT3U minimum weight reduced from plus 250 to plus 225 pounds; wheel and tyre options clarified with weight adjustments. · FA Formula Renault 2.0 (10-17) spec notes clarified: engine sealed, manual compliance required, tyre choice unrestricted, no alterations except repairs. · STU BMW N54/N55 3.0 classified at chart plus 3% minimum weight; N54 twin turbo not allowed. · STU Mini Cooper S SC pulley diameter reduced to 2.185 inches. · STU Honda K20C1 Turbo I4 exempted from 3% direct injection weight adder. · STU GT3U minimum weight increases 150 pounds to 250 pounds. · FA adds Formula Regional European Championship Tatuus F.3 T-318 or FR-19 as spec line car in Table 2. · STU Audi 1.8T Wagon removed; Porsche 944 1800cc weight to Chart, turbo inlet restrictor deleted. · STU-GT3 reclassified as STU-GT3U, effective 1 January 2026. · STU GT3 TCR may run 275-wide DOT tires with 100 lb weight penalty; A compound prohibited at 275. · SMX OE instrument cluster must stay unmodified and connected; aftermarket dash allowed if wiring only re-routed; alternate gauges now permitted; foot pedal comfort mods allowed without relocation. · STL STU Mazda Miata alternate front hubs Mazda Motorsports Development Part #0000-04-5HUB-S1 approved. · STU BMW N54/N55 turbo inlet restrictors now required per GCR definition; twin turbo conversion to single turbo clarified. · STU Mini Cooper S SC: 1900 stock pulley spec to 2.565 diameter; 2100 now permits 2.285 diameter pulley.showhide
STU Lotus Weight Reduction E&O #38919weightfasterweightSTU Lotus Elise SC and Exige SC weight reduced from 2450 to 2250 lbs.
STU STU-TCR Adjustments #38723weightslowerweightSTU-TCR gains GT3 TCR spec lines; 275 tyre option now costs 150 lb adder, up from 100 lb.
STU Lotus Weight Reduction #38772weight -50 lbsfasterweightLotus Evora GT4 minimum weight drops to 2700 lbs; Elise Cup R to 2250 lbs; Elise SC and Exige SC to 2450–2550 lbs.
FA Ligier JS F3 Tire Choice #38434tyres & wheelstyres & wheelsFA Ligier JS F3 front tires change to Hoosier 240/580R13 MS, rear to 300/590R13 MS.
STU 2.8-3.2L N/A Engine Allowances #38007tyres & wheelsfastertyres & wheelsSTU 2.8–3.2L N/A engines now permit 245 max tyre width; over 3150 lbs cars may run 275 with 2% weight penalty.
STU 2006-2015 Mazda Miata Intake Manifold #38422engineaddedengineSTU Mazda MZR intake manifold now allows Goodwin 61-2510 or Gato Performance 31972.
STU Requesting Approval of the JDM Honda h23a #38489cars addedaddedSTU Honda JDM H23a added, 2259 cc, minimum weight per chart, must meet ST engine regulations.
SM SMX Data Submission - Penalties #38248otheraddedSMX drivers must submit data acquisition files on time or face suspension and $250 fine.
SM Committee) SMX Penaly Clarification updated language #38337wordingwordingSMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fines, level 2 and 4 may carry $500 fines.
SM Clarify Tire Marking Regs #38005wordingwordingSM tire marking rules clarified: one Hoosier SM 7.5 P205/50/ZR17 set per Super Tour weekend, impound after first dry session, damaged tires may be replaced with used tires only.
STU Wheel Size Inconsistency #38018tyres & wheelstyres & wheelsSTU wheels capped at 18 inches diameter; under 2,850 lbs max 8 inches wide, over 2,850 lbs max 9 inches wide.
STU Table C: STU-GT3U Clarification #38268weightfasterweightSTU-GT3U minimum weight reduced from plus 250 to plus 225 pounds; wheel and tyre options clarified with weight adjustments.
FA Update Formula Renault 2.0 spec line notes #37853wordingwordingFA Formula Renault 2.0 (10-17) spec notes clarified: engine sealed, manual compliance required, tyre choice unrestricted, no alterations except repairs.
STU BMW N54/N55 Engine Allowance Follow Up #37447cars addedaddedSTU BMW N54/N55 3.0 classified at chart plus 3% minimum weight; N54 twin turbo not allowed.
STU STU Mini Cooper pulley size clarification re: letter #36980 #37717inductionfasterinductionSTU Mini Cooper S SC pulley diameter reduced to 2.185 inches.
STU Question About a Weight Modifier #37782weightfasterweightSTU Honda K20C1 Turbo I4 exempted from 3% direct injection weight adder.
STU Increase Minimum Weight #37919weight +100 lbsslowerweightSTU GT3U minimum weight increases 150 pounds to 250 pounds.
FA Classify FR European Championship car as spec line car in Table 2 #37658cars addedaddedFA adds Formula Regional European Championship Tatuus F.3 T-318 or FR-19 as spec line car in Table 2.
STU Audi 1.8t Wagon STU Table B #36685cars addedremovedcars addedSTU Audi 1.8T Wagon removed; Porsche 944 1800cc weight to Chart, turbo inlet restrictor deleted.
STU Merger GT3 to STU #37486wordingunclearSTU-GT3 reclassified as STU-GT3U, effective 1 January 2026.
STU GT3 TCR Tire allowance #37494tyres & wheelsaddedtyres & wheelsSTU GT3 TCR may run 275-wide DOT tires with 100 lb weight penalty; A compound prohibited at 275.
SM E&O SMX Regs 9.1.7.1.D.5.u-.w #37070wordingwordingSMX OE instrument cluster must stay unmodified and connected; aftermarket dash allowed if wiring only re-routed; alternate gauges now permitted; foot pedal comfort mods allowed without relocation.
STU Request to Remove Miata Hubs from General category #37138cars addedaddedSTL STU Mazda Miata alternate front hubs Mazda Motorsports Development Part #0000-04-5HUB-S1 approved.
STU BMW N54/N55 Engine Allowance #37146wordingwordingSTU BMW N54/N55 turbo inlet restrictors now required per GCR definition; twin turbo conversion to single turbo clarified.
STU R53 15% Pulley Request #36980enginefasterengineSTU Mini Cooper S SC: 1900 stock pulley spec to 2.565 diameter; 2100 now permits 2.285 diameter pulley.
2:26.227Thomas Noble · fastest of 18 · top 5 within 2.3s-1.656s (-1.12%)
2:25.824Thomas Noble · fastest of 17 · top 5 within 2.4s-2.586s (-1.74%)
145.3Thomas Noble+1.1 mph (+0.8%)
2:01.560Hans Peter · fastest of 13 · top 5 within 2.0s-2.714s (-2.18%)
2:01.790Dudley Fleck · fastest of 12 · top 5 within 3.3s-2.956s (-2.37%)
160.0Brandon Schwarz+9.4 mph (+6.3%)
-24.034squal -24.667s
83.5%qual 83.1%
2:41.106Ethan Goulart · fastest of 49 · top 5 within 0.5s-1.103s (-0.68%)
2:41.486Brett Kowalski · fastest of 43 · top 5 within 0.3s-2.262s (-1.38%)
119.9Alex Bertagnoli-1.4 mph (-1.2%)
+15.662squal +14.879s
110.7%qual 110.2%
8 rule changes (STU: 4, SM: 4)2 aero · 1 engine · 1 induction · 2 wording · 2 other · SMX Spec MX-5 camera requirement: non-functioning recorder now will instead of may warrant penalty or disqualification. · SM and SMX must run latest AIM Data Logger Spec MX-5 ECU Protocol, effective 2024-09-01. · SMX Mazda MX-5 OE versus OEM definitions clarified in GCR section 9.1.7.1; wording change only. · SM and SMX now allow an alternate shifter bushing at the bottom of the shift lever. · STU RWD turbo cars no longer required to reduce inlet restrictor by 1 mm from table minimum. · STU Mini Cooper S SC gains alternate LEAP OMICRON hood scoop part LEP-OMICRON3 as permitted option. · STU BMW S54 B32 OEM dry sump oiling system now permitted. · STL and STU now permit electric power steering pumps, OEM electric-assisted steering, or column-mounted electric steering assist systems.showhide
SM SMX Camera Rule Correction #36496wordingwordingSMX Spec MX-5 camera requirement: non-functioning recorder now will instead of may warrant penalty or disqualification.
SM Committee) AIM ECU Protocol #36556engineaddedengineSM and SMX must run latest AIM Data Logger Spec MX-5 ECU Protocol, effective 2024-09-01.
SM Committee) OE versus OEM Definitons #36608wordingwordingSMX Mazda MX-5 OE versus OEM definitions clarified in GCR section 9.1.7.1; wording change only.
SM Committee) Shifter Bushing #36611otheraddedSM and SMX now allow an alternate shifter bushing at the bottom of the shift lever.
STU RWD Turbo Disadvantage #36255inductionfasterinductionSTU RWD turbo cars no longer required to reduce inlet restrictor by 1 mm from table minimum.
STU Letter #35397 addendum #35453aeroaddedaeroSTU Mini Cooper S SC gains alternate LEAP OMICRON hood scoop part LEP-OMICRON3 as permitted option.
STU S54 Drysump #35464otheraddedSTU BMW S54 B32 OEM dry sump oiling system now permitted.
STU ST Electric-Assisted Steering Systems #35066aeroaddedaeroSTL and STU now permit electric power steering pumps, OEM electric-assisted steering, or column-mounted electric steering assist systems.
2:00.389Johan Schwartz · fastest of 13 · top 5 within 2.3s-0.226s (-0.19%)
2:02.302Mark Liller · fastest of 14 · top 5 within 1.6s-30.055s (-19.73%)
144.0Mark Liller+0.1 mph (+0.1%)
2:14.986Danny Steyn · fastest of 52 · top 5 within 0.1s+0.322s (+0.24%)
2:16.229Julian DaCosta · fastest of 46 · top 5 within 0.3s-2.878s (-2.07%)
120.3Jim Drago+1.1 mph (+0.9%)
+13.927squal +14.597s
111.4%qual 112.1%
11 rule changes (STU: 3, FA: 7, SM: 1)3 weight · 2 cars added · 1 engine · 1 induction · 1 tyres & wheels · 2 wording · 1 other · STU adds 2022 Toyota GR Cup and GR86 Cup, both 2387cc, 2700 lbs, 18-inch wheels, 245/620R18 slicks. · FA Pro Formula Mazda front wheel width minimum raised to 10 inches, rear to 14 minimum and 15 maximum. · FA Pro Formula Mazda maximum bodywork width behind front wheels increases to 51.97 inches, from 51.17 inches. · FA MSR Formula Mazda FMzR added to Table 2 classification. · STU Mazda BP5A now classified at 1839 cc displacement, 2510 lbs minimum weight, alternate intake manifold permitted. · STU minimum weights adjusted: 2450 cc to 2595 lbs, 2600 cc to 2710 lbs. · Unable to complete: rule text does not show the spec line to be added to FA Table 1 for BDA displacement. · SM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore. · Formula Renault 2.0 (10-17) reclassified from FX to FA spec line; minimum weight reduced 1300 to 1280 lbs, restrictor removed. · FA Swift 016 2.3L Mazda Duratec restrictor increases to 32mm, minimum weight drops to 1420 lbs. · Pro Formula Mazda allows street or bridge port, unmodified OEM lower intake manifold, 70mm throttle body, wing height to 99cm, bodywork width to 132cm.showhide
STU 2022 Toyota GR Cup for STU #34449cars addedaddedSTU adds 2022 Toyota GR Cup and GR86 Cup, both 2387cc, 2700 lbs, 18-inch wheels, 245/620R18 slicks.
FA Simplify Pro Formula Mazda wheel allowance #34190tyres & wheelsslowertyres & wheelsFA Pro Formula Mazda front wheel width minimum raised to 10 inches, rear to 14 minimum and 15 maximum.
FA E&O - Correct Pro Formula Mazda spec line dimensional equivalent #34085wordingwordingFA Pro Formula Mazda maximum bodywork width behind front wheels increases to 51.97 inches, from 51.17 inches.
FA Add new spec line for MSR Formula Mazda FMzR to Table 2 #34139cars addedaddedFA MSR Formula Mazda FMzR added to Table 2 classification.
STU Alternate OEM Miata Intake Manifold #33827engineaddedengineSTU Mazda BP5A now classified at 1839 cc displacement, 2510 lbs minimum weight, alternate intake manifold permitted.
STU E&O STU NA Weight Chart. #33737weightfasterweightSTU minimum weights adjusted: 2450 cc to 2595 lbs, 2600 cc to 2710 lbs.
FA BDA Displacement #33431otherunclearUnable to complete: rule text does not show the spec line to be added to FA Table 1 for BDA displacement.
SM BOP for NB1 and NB2 #32309weightslowerweightSM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore.
FA Reclassify 2010-2017 Formula Renault 2.0 as a spec line car in FA #33395weightfasterweightFormula Renault 2.0 (10-17) reclassified from FX to FA spec line; minimum weight reduced 1300 to 1280 lbs, restrictor removed.
FA Change Swift 016 2.3L restrictor size and minimum weight #33472induction -30 lbsfasterinductionFA Swift 016 2.3L Mazda Duratec restrictor increases to 32mm, minimum weight drops to 1420 lbs.
FA Pro Formula Mazda Dimension E&O #33160wordingwordingPro Formula Mazda allows street or bridge port, unmodified OEM lower intake manifold, 70mm throttle body, wing height to 99cm, bodywork width to 132cm.
2:00.615Johan Schwartz · fastest of 21 · top 5 within 2.6s+0.667s (+0.56%)
2:32.357Mark Liller · fastest of 19 · top 5 within 4.3s+31.874s (+26.46%)
143.9Johan Schwartz+0.1 mph (+0.1%)
1:44.703Chip Romer · fastest of 7 · top 5 within 4.0s+3.158s (+3.11%)
1:48.507Alex Mayer · fastest of 4 · top 4 within 4.2s+5.400s (+5.24%)
154.6Austin Hill-1.4 mph (-0.9%)
-43.850squal -15.912s
71.2%qual 86.8%
2:14.664Danny Steyn · fastest of 60 · top 5 within 0.2s+0.112s (+0.08%)
2:19.107Travis Wiley · fastest of 58 · top 5 within 0.9s+2.648s (+1.94%)
119.2Jonathan Neudorf-0.6 mph (-0.5%)
-13.250squal +14.049s
91.3%qual 111.6%
29 rule changes (STU: 21, FA: 7, SM: 1)6 weight · 5 engine · 3 cars added · 2 aero · 2 tyres & wheels · 11 wording · STU Mazda 13B Turbo added as Chart Limited displacement, streetport only, alternative turbos only. · STU OEM louver vents no longer count against vent allowance or 200 square inch limit. · STU non-4-valve engines gain 9% base engine weight reduction allowance; 2400cc minimum weight drops 1 lb to 2595. · STU normally-aspirated engines 2976cc–3200cc with single throttle body lose 10% base engine weight reduction allowance. · ST removes redundant language about engine balance shaft removal and alternate pulley installation. · FA Ligier JS F3 must comply with FR Americas rules; competitors need current FR Americas Championship Sporting Regulations, Onroak manual, and HPD engine specs. · FA sealed engines now require full inspection by stewards; competitor pays all reassembly and resealing costs. · FA Formula Lites FL15 and FR Americas Ligier JS F3 engine sealing requirements clarified with regulatory references. · STU cars that qualified for 9 inch wheels in 2021 may continue running them through 2022 only. · STU splitter definition clarified: must attach to lowest point of front, have no vertical deviations. · FA: transverse gearbox shafts prohibited except final drive and motorcycle gearbox in Formula 1000. · FA Swift 016 2.5 liter aero spec now references 2.3 liter notes instead of N notes. · SM Majors must run authorized Penske shock and mount; Regional competitors not required until further evaluation. · STU BMW E36 M3 (95-99) S52B32 minimum weight cut to 3110 lbs from 3200, displacement to 3152 cc. · STU BMW S50B32 Euro maximum displacement 3201 cc, minimum weight 3300 lbs, permits 0.040 overbore and 0.5 compression increase. · ST engine swap origin rule narrowed: North America changed to United States only for case-by-case approval. · STU Honda CRX 84-91 and Civic Del Sol 93-97 both ineligible for front-wheel-drive weight reductions. · STU wheel width rule clarified: under 2950 lbs uses max 8.0 inches, 2950 lbs and over uses max 9.0 inches. · STU single-throttle body cars get lower minimum weights: 2450cc to 2596 lbs, 2500cc to 2635 lbs, 2550cc to 2675 lbs. · FA Pro Formula Mazda now allows street port or bridge port; porting was previously not permitted. · STU single throttle body weight reduction removed; minimum weights revised down to 2990 lbs at 3000cc from 3300 lbs. · STU Audi A4 1.8T minimum weight fixed to 3050 lbs, K04 turbo removed, VF30 with 35mm restrictor required; Porsche 944 1800 weight fixed to 3050 lbs, VW/Audi 1.8L engine removed, 35mm inlet restrictor required. · STL and STU Improved Touring vehicles must now conform to section 9.1.4 Tires & Wheels. · FA adds Honda K20Z3 2.0L at 1350 lbs and Mazda MZR 2.0L at 1300 lbs; removes 4A-GE 1.8L and MZR 2.0L from Table 2; raises 1615cc baseline to 1250 lbs. · STU engines may delete balance shafts and plug openings; alternate pulleys or gears allowed only for timing belt or chain operation. · STU hood vents now allow louvers within 200 square inches. · STU adds Honda K23 with 2354 cc displacement and chart minimum weight, K24 block allowed with K23 internals and head. · STU Honda K23 relaxes internal engine requirement, now needs only K23 crankshaft. · STL/STU intake manifold and cylinder head porting clarified as free; intake and exhaust porting wording removed.showhide
STU Request Mazda 13 B turbo #32668cars addedaddedSTU Mazda 13B Turbo added as Chart Limited displacement, streetport only, alternative turbos only.
STU Hood Vents and Intercooler Scoops #32733aeroaddedaeroSTU OEM louver vents no longer count against vent allowance or 200 square inch limit.
STU Non 4 valve weight reduction removed #32808weightfasterweightSTU non-4-valve engines gain 9% base engine weight reduction allowance; 2400cc minimum weight drops 1 lb to 2595.
STU Error in new minimum weight table when combined with other text #32711engineslowerengineSTU normally-aspirated engines 2976cc–3200cc with single throttle body lose 10% base engine weight reduction allowance.
STU Redundant Language in May GCR #32713wordingwordingST removes redundant language about engine balance shaft removal and alternate pulley installation.
FA Update FR Americas rulebook requirement #32491wordingwordingFA Ligier JS F3 must comply with FR Americas rules; competitors need current FR Americas Championship Sporting Regulations, Onroak manual, and HPD engine specs.
FA Clarify verification of sealed engine compliance #32522wordingwordingFA sealed engines now require full inspection by stewards; competitor pays all reassembly and resealing costs.
FA Clarify Formula Lites and FR Americas sealed engine requirement #32523wordingwordingFA Formula Lites FL15 and FR Americas Ligier JS F3 engine sealing requirements clarified with regulatory references.
STU Opposed to the Proposed STU Weight Chart #32381tyres & wheelsaddedtyres & wheelsSTU cars that qualified for 9 inch wheels in 2021 may continue running them through 2022 only.
STU Clarification request for GCR 9.1.4.D.3.a Splitter Definition #32414wordingwordingSTU splitter definition clarified: must attach to lowest point of front, have no vertical deviations.
FA E&O FA Transmission section #32251wordingwordingFA: transverse gearbox shafts prohibited except final drive and motorcycle gearbox in Formula 1000.
FA E&O Swift 016 2.5 liter Aero column #32363wordingwordingFA Swift 016 2.5 liter aero spec now references 2.3 liter notes instead of N notes.
SM Update GCR Section 9.1.7.3.A.1. #32217wordingwordingSM Majors must run authorized Penske shock and mount; Regional competitors not required until further evaluation.
STU Request Adjustment to Min Weight for STU BMW E36 M3 (95-99) #31535weight -90 lbsfasterweightSTU BMW E36 M3 (95-99) S52B32 minimum weight cut to 3110 lbs from 3200, displacement to 3152 cc.
STU BMW E36 M3 Canadian (North American) S50B32 engine #31866engineaddedengineSTU BMW S50B32 Euro maximum displacement 3201 cc, minimum weight 3300 lbs, permits 0.040 overbore and 0.5 compression increase.
STU Engine Swap Origin Country #32209wordingwordingST engine swap origin rule narrowed: North America changed to United States only for case-by-case approval.
STU CRX/Civic Del Sol #32214weightslowerweightSTU Honda CRX 84-91 and Civic Del Sol 93-97 both ineligible for front-wheel-drive weight reductions.
STU Error correction #32383wordingwordingSTU wheel width rule clarified: under 2950 lbs uses max 8.0 inches, 2950 lbs and over uses max 9.0 inches.
STU Single TB Weight Modifiers Add to Chart #32393weightfasterweightSTU single-throttle body cars get lower minimum weights: 2450cc to 2596 lbs, 2500cc to 2635 lbs, 2550cc to 2675 lbs.
FA Closing the Gap #31934enginefasterengineFA Pro Formula Mazda now allows street port or bridge port; porting was previously not permitted.
STU Single TB Weight Modifiers #31449weightfasterweightSTU single throttle body weight reduction removed; minimum weights revised down to 2990 lbs at 3000cc from 3300 lbs.
STU Request to Remove A4 1.8t from STU Spec Line Tables #31465weightslowerweightSTU Audi A4 1.8T minimum weight fixed to 3050 lbs, K04 turbo removed, VF30 with 35mm restrictor required; Porsche 944 1800 weight fixed to 3050 lbs, VW/Audi 1.8L engine removed, 35mm inlet restrictor required.
STU Improved Touring Tires #32063tyres & wheelstyres & wheelsSTL and STU Improved Touring vehicles must now conform to section 9.1.4 Tires & Wheels.
FA Reorganize Tables 1 and 2 #31985cars addedaddedFA adds Honda K20Z3 2.0L at 1350 lbs and Mazda MZR 2.0L at 1300 lbs; removes 4A-GE 1.8L and MZR 2.0L from Table 2; raises 1615cc baseline to 1250 lbs.
STU Request Allowance for Balance Shaft Delete in STU #31434enginefasterengineSTU engines may delete balance shafts and plug openings; alternate pulleys or gears allowed only for timing belt or chain operation.
STU Request Louvers in hood vents #31916aeroaddedaeroSTU hood vents now allow louvers within 200 square inches.
STU Request to Add Honda K23 Spec Line #30682cars addedaddedSTU adds Honda K23 with 2354 cc displacement and chart minimum weight, K24 block allowed with K23 internals and head.
STU RE: Aug FT letter 30682 #31060enginefasterengineSTU Honda K23 relaxes internal engine requirement, now needs only K23 crankshaft.
STU Throttling Device Clarification #31323wordingwordingSTL/STU intake manifold and cylinder head porting clarified as free; intake and exhaust porting wording removed.
1:47.078Joe Moser · fastest of 30 · top 5 within 2.0s-1.843s (-1.69%)
1:47.441Joe Moser · fastest of 28 · top 5 within 1.8s-1.946s (-1.78%)
146.9Kip VanSteenburg
1:29.701James French · fastest of 18 · top 5 within 2.7s-0.256s (-0.28%)
1:30.650James French · fastest of 17 · top 5 within 6.1s-0.715s (-0.78%)
155.5James French
-16.791squal -17.377s
84.4%qual 83.8%
1:57.695Brian Henderson · fastest of 90 · top 5 within 0.5s-0.611s (-0.52%)
1:58.837Brian Henderson · fastest of 88 · top 5 within 0.3s-0.263s (-0.22%)
119.8Kyle Greenhill
+11.396squal +10.617s
110.6%qual 109.9%
35 rule changes (STU: 12, FA: 22, SM: 1)7 cars added · 4 engine · 2 weight · 1 aero · 1 induction · 1 suspension & brakes · 17 wording · 2 other · FA Mazda MZR 2.0 engine name shortened to Mazda MZR; Honda Civic K20Z3 name clarified. · Toyota 1800 moves from FA Table 1 to FA Table 2 Spec Line Cars. · FA Swift 016 Mazda MZR/Ford Duratec wheel width spec clarified: front 10, rear 14 min & 15 max inches. · FA rule text reorganized: purpose-built and ex-pro cars moved to Table 1, spec line cars to Table 2, with clarified engine note applicability. · FA Mazda MZR/Ford Duratec 2296cc and 2500cc moved from Table 1 to Table 2. · FA Mazda MZR 2.0L and Honda Civic K20Z3 change from 5-speed sequential to 5-speed. · STU fender flare wording clarified: flare of exterior contour may not change wheel opening size, location or shape from side view. · STU Mazda 12A Bridgeport weight reduced from 2550 lbs to 2350 lbs. · FA Mazda MZR 2.0 limited to Ralt RT40, RT41, Swift 008, 014 chassis; Honda Civic K20Z3 removes Swift 016 chassis. · FA Swift 016 2.3 liter engine name corrected to Mazda MZR/Ford Duratec. · FA Swift 016 2.5 liter engine name corrected to Mazda MZR/Ford Duratec. · FA removes four spec lines (E–H); spec line D changes from Ford Duratec/Mazda MZR 2500 to Honda B16 1615, loses 29mm restrictor, weight 1400 to 1175 lbs. · STU fender flare rules clarified: maximum 2 inches total, must cover tire contact patch from above, cannot alter body configuration or wheel opening geometry. · FA Spec Lines C, I, K weights adjusted: C to 1175 lbs, I to 1175 lbs, K to 1175 lbs. · FA purpose-built and ex-Pro Atlantic cars remove sequential trans. 25 lb penalty redundant reference. · FA Ligier car name corrected to FR Americas Ligier JS F3. · FA Ford Duratec/Mazda MZR Spec Line D clarifies valve specification to 4 per cylinder, no performance change. · FA Honda Civic K20Z3 intake manifold and throttle body now may use AT Power Direct-To-Head 45mm individual throttle bodies PN 102-104-00020 as alternative. · SM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture. · STU Honda S2000 now allows F20/F22 K24 crankshaft with chart weight for achieved displacement. · ST oil coolers and filters now explicitly listed as addable or substitutable parts in vents and breathers section. · FA Ford Duratec/Mazda MZR intake restrictor reduced from 32mm to 30mm SIR; Swift 016 2.5 Mazda restrictor reduced from 35mm to 33mm SIR. · FA Toyota 4A-GE Spec Lines A and B: engine designation and valve configuration clarified, weights and displacement unchanged. · FA Ford BD Series engine displacement increases from 1600 cc to 1615 cc; minimum weight stays 1200 lbs. · FA Ford Duratec/Mazda MZR and Honda B16 engines both now limited to 1615cc displacement; both lose NA restrictor requirement. · Pro Formula Mazda engine specifications moved from Table 1 to Table 2 spec line notes; no performance changes. · ST 90-05 Mazda Miata allowed alternate front wheel hub Mazda Motorsports Development Part #0000-04-5HUB-S1. · ST cars may now relocate ABS actuation hardware and wiring anywhere in the engine compartment. · STU Porsche PDK automatic transmission limited to 8 forward speeds; sequential DCT systems require 3.5% minimum weight increase. · STU Mazda 13B Street Port 2400 removes choke location rule, allows auto-type 2bbl with any dual-Y manifold. · STU driveshaft and half-shafts now explicitly permitted in steel or aluminum, removing OEM material requirement. · Formula Lites Crawford FL15 added to FA classification effective 2021-01-01. · STU Mazda 13B Spec and Bridge Port removed; Street Port added at 2400 lbs minimum weight. · ST aero devices and reference areas must include end plates, exclude fasteners under 1/2" protrusion.showhide
FA E&O Table 2 engine names #31085wordingwordingFA Mazda MZR 2.0 engine name shortened to Mazda MZR; Honda Civic K20Z3 name clarified.
FA Move Toyota 1800 to Table 2 #30822cars addedcars addedToyota 1800 moves from FA Table 1 to FA Table 2 Spec Line Cars.
FA E&O Swift 016 wheel width reference #30939wordingwordingFA Swift 016 Mazda MZR/Ford Duratec wheel width spec clarified: front 10, rear 14 min & 15 max inches.
FA Update FA rules package #30717wordingwordingFA rule text reorganized: purpose-built and ex-pro cars moved to Table 1, spec line cars to Table 2, with clarified engine note applicability.
FA Move Mazda MZR/Ford Duratec 2296cc and 2500cc to Table 2 #30718cars addedaddedFA Mazda MZR/Ford Duratec 2296cc and 2500cc moved from Table 1 to Table 2.
FA Clean up Table 2 Mazda MZR 2.0L and Honda Civic K20Z3 spec lines #30719wordingwordingFA Mazda MZR 2.0L and Honda Civic K20Z3 change from 5-speed sequential to 5-speed.
STU STU Fender flares #30696wordingwordingSTU fender flare wording clarified: flare of exterior contour may not change wheel opening size, location or shape from side view.
STU Request weight reduction for 12A bridgeport motor in Miata #30751weight -200 lbsfasterweightSTU Mazda 12A Bridgeport weight reduced from 2550 lbs to 2350 lbs.
FA E&O Mazda MZR 2.0 and Honda Civic K20Z3 chassis eligibility #30632cars addedremovedcars addedFA Mazda MZR 2.0 limited to Ralt RT40, RT41, Swift 008, 014 chassis; Honda Civic K20Z3 removes Swift 016 chassis.
FA Correct engine name in Swift 016 2.3 liter spec line #30447wordingwordingFA Swift 016 2.3 liter engine name corrected to Mazda MZR/Ford Duratec.
FA Correct engine name in Swift 016 2.5 liter spec line #30448wordingwordingFA Swift 016 2.5 liter engine name corrected to Mazda MZR/Ford Duratec.
FA Revise Table 1 Spec Lines and clarify application of Engine Notes #30456cars addedfastercars addedFA removes four spec lines (E–H); spec line D changes from Ford Duratec/Mazda MZR 2500 to Honda B16 1615, loses 29mm restrictor, weight 1400 to 1175 lbs.
STU Request for Fender Flare Clarification #30375wordingwordingSTU fender flare rules clarified: maximum 2 inches total, must cover tire contact patch from above, cannot alter body configuration or wheel opening geometry.
FA Update Table 1 Weights for Spec Lines C, I, and K #30355weight -25 lbsfasterweightFA Spec Lines C, I, K weights adjusted: C to 1175 lbs, I to 1175 lbs, K to 1175 lbs.
FA Remove redundant reference in Table 2 spec line #30366wordingwordingFA purpose-built and ex-Pro Atlantic cars remove sequential trans. 25 lb penalty redundant reference.
FA Correct the name of the FR Americas car #30369wordingwordingFA Ligier car name corrected to FR Americas Ligier JS F3.
FA Clean up Spec Line D in Table 1 #30372wordingwordingFA Ford Duratec/Mazda MZR Spec Line D clarifies valve specification to 4 per cylinder, no performance change.
FA Table 2 Honda K20Z3 request #30386engineaddedengineFA Honda Civic K20Z3 intake manifold and throttle body now may use AT Power Direct-To-Head 45mm individual throttle bodies PN 102-104-00020 as alternative.
SM Updates - Obsolete Parts & BOP Parts #30438wordingaddedSM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture.
STU Provision for Interchangeable Engine Components Already Allowed #30342engineaddedengineSTU Honda S2000 now allows F20/F22 K24 crankshaft with chart weight for achieved displacement.
STU ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wordingwordingST oil coolers and filters now explicitly listed as addable or substitutable parts in vents and breathers section.
FA E&O FA Intake Restrictors #30273inductionslowerinductionFA Ford Duratec/Mazda MZR intake restrictor reduced from 32mm to 30mm SIR; Swift 016 2.5 Mazda restrictor reduced from 35mm to 33mm SIR.
FA Clean up Spec Lines A and B in Table 1 #30274wordingwordingFA Toyota 4A-GE Spec Lines A and B: engine designation and valve configuration clarified, weights and displacement unchanged.
FA Clean up Spec Line C in Table 1 #30275enginefasterengineFA Ford BD Series engine displacement increases from 1600 cc to 1615 cc; minimum weight stays 1200 lbs.
FA Clean up Spec Lines J and L in Table 1 #30276engineengineFA Ford Duratec/Mazda MZR and Honda B16 engines both now limited to 1615cc displacement; both lose NA restrictor requirement.
FA Move engine specifications to Pro Formula Mazda spec line notes #30278wordingwordingPro Formula Mazda engine specifications moved from Table 1 to Table 2 spec line notes; no performance changes.
STU Super Touring Alternate Miata Hubs #30345cars addedaddedST 90-05 Mazda Miata allowed alternate front wheel hub Mazda Motorsports Development Part #0000-04-5HUB-S1.
STU Brake Component Relocation #29990suspension & brakessuspension & brakesST cars may now relocate ABS actuation hardware and wiring anywhere in the engine compartment.
STU Porsche PDK #30081wordingwordingSTU Porsche PDK automatic transmission limited to 8 forward speeds; sequential DCT systems require 3.5% minimum weight increase.
STU Reference Letter #29333 Proposed STU 13B Spec Line Changes #30086wordingwordingSTU Mazda 13B Street Port 2400 removes choke location rule, allows auto-type 2bbl with any dual-Y manifold.
STU Drive Shaft Request #30087otherotherSTU driveshaft and half-shafts now explicitly permitted in steel or aluminum, removing OEM material requirement.
FA Request to classify Formula Lites Crawford FL15 #29702cars addedaddedFormula Lites Crawford FL15 added to FA classification effective 2021-01-01.
STU 13B Rules Adjustment #29333cars addedremovedcars addedSTU Mazda 13B Spec and Bridge Port removed; Street Port added at 2400 lbs minimum weight.
STU Request clarification on wing measurement #29640aeroaeroST aero devices and reference areas must include end plates, exclude fasteners under 1/2" protrusion.
2:27.883David Fiorelli · fastest of 14 · top 5 within 4.1s
2:28.410Anthony Geraci · fastest of 14 · top 5 within 3.1s
144.2David Fiorelli
2:04.274Spencer Brockman · fastest of 11 · top 5 within 2.7s
2:04.746Spencer Brockman · fastest of 10 · top 5 within 2.4s
150.6Hans Peter
-23.664squal -23.609s
84.1%qual 84.0%
2:42.209Kyle Greenhill · fastest of 77 · top 5 within 0.5s
2:43.748Preston Pardus · fastest of 75 · top 5 within 1.0s
121.3Kyle Greenhill
+15.338squal +14.326s
110.3%qual 109.7%
34 rule changes (STU: 17, FA: 15, SM: 2)7 engine · 3 cars added · 2 weight · 1 induction · 1 suspension & brakes · 1 tyres & wheels · 16 wording · 3 other · SM allows aftermarket radiators in original location with stock OEM cooling fan, and permits 1990-1997 cars to install upper radiator seal NA75-50-OK7A. · STU fender flare rule reworded: now per-corner up to 2" total, 1% weight penalty applies to entire modification. · SM rear brake caliper may use single bracket under upper retaining bolt head to prevent pin failure. · STL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis percentage additions, subtractions, and fixed pounds. · STL STU rear wing Gurney flap terminology clarified from wicker to Gurney flap in mounting and chord rules. · FA stock engine weight adjustment request denied; modified engines now permitted in FA. · STU request for alternate intake manifold denied; no change to rules. · GT3 and STU add Borg-Warner EFR6258 turbocharger to approved turbo lists. · STU large displacement turbo engines limited by GCR turbo list; no BoP change granted. · STU sequential shifters referred to Board of Directors for approval; no rule change effective. · FA engine modifications clarified: bore/stroke/flywheel unrestricted within displacement limits, distributor/ignition installation restricted, compression ratio machining allowed, table references updated. · FA transmissions limited to five forward speeds and operational reverse unless Table 2 notes otherwise. · FA Swift 016 Mazda Duratec: clarify Gurney flap wording, dimensions and allowed locations unchanged. · STU Mazda 13B Bridge Port and Street Port added with 2550 lbs and 2250 lbs minimum weight respectively. · FA removes Volkswagen 1835cc SOHC engine specification line from Table 1. · FA engine rules clarify that blocks and heads must be OEM unless the tables note otherwise; wording only. · FA Formula 1000 motorcycle-based engines gain maximum compression ratio of 14.5:1, up from 13.5:1. · FA removes Ex-FSV wheel width rules, all cars now front ten inches, rear fourteen to fifteen inches. · FA Formula 3 permitted engine years extended from 1997–2008 to 1997–2017. · STU Honda S2000 gains HKS Supercharger kits 12001-AH006 and 12001-AH010 as allowed options. · STU Lotus Elise Cup R and SC Exige SC gain 100 lbs minimum weight to 2300, 2500. · STU Volkswagen GTI/GLI MK5 and Jetta Mk4 may now install turbo inlet restrictor in OEM housing, per TIR spec. · STU Honda K20C1 Turbo I4 restrictor reduces from 36mm to 35mm. · STU GM Ecotech LNF now permitted without turbo, with LE5 head and intake manifold, meeting STL specs. · STU Porsche 944 now permits VW/Audi 1.8L and 2.0L turbo engines as alternates to original. · FA Table 1 engine notes now apply only to Table 1, not Table E; FA Table 2 Pro Formula Mazda engine references Table 1 specs. · STU vehicles over 2951 lbs base weight may use 9 inch wide wheels, changed from 2950 lbs. · STU turbocharged engines now use base weight instead of minimum weight; DFI cars add 3% to base weight. · Formula 1000 motorcycle-based engine up to 1000cc added to FA with unrestricted throttle bodies and ECUs. · unclear · FA Swift 016 2.3L Mazda Duratec restrictor reduced from 33mm to 31mm SIR. · FA wheel diameter and width specifications moved from Bodywork subsection to General section. · FA Mazda MZR 2.0 engine use restricted to Ralt RT40, Ralt RT41, and Swift 014 chassis only. · STU allows OEM electronic throttle bodies, manual conversion, cam changes, and manual-to-electronic conversion with same inner diameter.showhide
SM Radiator E&O Clarifications #29294wordingwordingSM allows aftermarket radiators in original location with stock OEM cooling fan, and permits 1990-1997 cars to install upper radiator seal NA75-50-OK7A.
STU Request for Advanced Aero Rule Wording Clarification. #29124wordingwordingSTU fender flare rule reworded: now per-corner up to 2" total, 1% weight penalty applies to entire modification.
SM Modifications to prevent failures of Rear Brake Caliper Pin #28953suspension & brakessuspension & brakesSM rear brake caliper may use single bracket under upper retaining bolt head to prevent pin failure.
STU Minimum Weight Determination #27695wordingwordingSTL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis percentage additions, subtractions, and fixed pounds.
STU ST Gurney flap Wicker clarification #29012wordingwordingSTL STU rear wing Gurney flap terminology clarified from wicker to Gurney flap in mounting and chord rules.
FA Request to Adjust FB Weight for Stock Engines #29005wordingunclearFA stock engine weight adjustment request denied; modified engines now permitted in FA.
STU Request for Alternate Intake Manifold #26514wordingunclearSTU request for alternate intake manifold denied; no change to rules.
STU Request for Addition to GT3 Approved Turbo List #27576cars addedaddedGT3 and STU add Borg-Warner EFR6258 turbocharger to approved turbo lists.
STU Request BoP for my Car #29004wordingunclearSTU large displacement turbo engines limited by GCR turbo list; no BoP change granted.
STU Sequential Shifters in STU #29031wordingunclearSTU sequential shifters referred to Board of Directors for approval; no rule change effective.
FA E&O permitted engine modifications #28831wordingwordingFA engine modifications clarified: bore/stroke/flywheel unrestricted within displacement limits, distributor/ignition installation restricted, compression ratio machining allowed, table references updated.
FA E&O Transmissions #28832wordingwordingFA transmissions limited to five forward speeds and operational reverse unless Table 2 notes otherwise.
FA Swift 016 Gurney flap wicker clarification #28884wordingwordingFA Swift 016 Mazda Duratec: clarify Gurney flap wording, dimensions and allowed locations unchanged.
STU Rotary Help #27833cars addedaddedSTU Mazda 13B Bridge Port and Street Port added with 2550 lbs and 2250 lbs minimum weight respectively.
FA Remove redundant spec line in Table 1 #28720engineremovedengineFA removes Volkswagen 1835cc SOHC engine specification line from Table 1.
FA E&O general engine rules #28772wordingwordingFA engine rules clarify that blocks and heads must be OEM unless the tables note otherwise; wording only.
FA Request higher compression ratio and prior weights for F1000 cars #28162enginefasterengineFA Formula 1000 motorcycle-based engines gain maximum compression ratio of 14.5:1, up from 13.5:1.
FA Remove redundant wheel dimension provisions #28554tyres & wheelstyres & wheelsFA removes Ex-FSV wheel width rules, all cars now front ten inches, rear fourteen to fifteen inches.
FA E&O Formula 3 spec line #28596engineaddedengineFA Formula 3 permitted engine years extended from 1997–2008 to 1997–2017.
STU Request to approve Honda S2000 HKS supercharger #27281otheraddedSTU Honda S2000 gains HKS Supercharger kits 12001-AH006 and 12001-AH010 as allowed options.
STU Request BoP on the Lotus #27637weight +100 lbsslowerweightSTU Lotus Elise Cup R and SC Exige SC gain 100 lbs minimum weight to 2300, 2500.
STU Turbo Inlet Restrictor On MK5 Volkswagen #27704otherslowerSTU Volkswagen GTI/GLI MK5 and Jetta Mk4 may now install turbo inlet restrictor in OEM housing, per TIR spec.
STU Honda K20C1 removal #27732engineslowerengineSTU Honda K20C1 Turbo I4 restrictor reduces from 36mm to 35mm.
STU Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0 #27884engineaddedengineSTU GM Ecotech LNF now permitted without turbo, with LE5 head and intake manifold, meeting STL specs.
STU Alternate Engine for Porsche 944 #28259engineaddedengineSTU Porsche 944 now permits VW/Audi 1.8L and 2.0L turbo engines as alternates to original.
FA FA weight correction/clarification #28430wordingwordingFA Table 1 engine notes now apply only to Table 1, not Table E; FA Table 2 Pro Formula Mazda engine references Table 1 specs.
STU Please Modify the STU Wheel Size Rule for Clarity #27694weightfasterweightSTU vehicles over 2951 lbs base weight may use 9 inch wide wheels, changed from 2950 lbs.
STU Turbo Engine Cars Base Weight #28032wordingwordingSTU turbocharged engines now use base weight instead of minimum weight; DFI cars add 3% to base weight.
FA Request to merge FB into FA #25611cars addedaddedFormula 1000 motorcycle-based engine up to 1000cc added to FA with unrestricted throttle bodies and ECUs.
FA Suggestions for FB/F1000 into FA #27319otherunclearunclear
FA Change Swift 016 - 2.3 liter Mazda Duratec restrictor size #27880inductionslowerinductionFA Swift 016 2.3L Mazda Duratec restrictor reduced from 33mm to 31mm SIR.
FA Move wheel dimensions from Bodywork subsection to #27493wordingwordingFA wheel diameter and width specifications moved from Bodywork subsection to General section.
FA Table 2 Mazda MZR 2.0 E&O #27640wordingwordingFA Mazda MZR 2.0 engine use restricted to Ralt RT40, Ralt RT41, and Swift 014 chassis only.
STU Request for an electronic throttle body #27342engineaddedengineSTU allows OEM electronic throttle bodies, manual conversion, cam changes, and manual-to-electronic conversion with same inner diameter.
1:59.948Kevin Boehm · fastest of 25 · top 5 within 3.5s
2:00.483Kevin Boehm · fastest of 25 · top 5 within 2.5s
143.8Kevin Boehm
1:41.545Dario Cangialosi · fastest of 8 · top 5 within 2.8s
1:43.107Dario Cangialosi · fastest of 8 · top 5 within 1.8s
155.9Kent Vaccaro
-17.376squal -18.403s
85.6%qual 84.7%
2:14.552Todd Buras · fastest of 60 · top 5 within 0.2s
2:16.459Elivan Goulart · fastest of 56 · top 5 within 0.4s
119.8Jim Drago
+15.976squal +14.604s
113.3%qual 112.2%
33 rule changes (STU: 22, FA: 7, SM: 4)6 engine · 5 cars added · 3 aero · 3 induction · 2 weight · 1 removed · 9 wording · 4 other · FA Honda Civic K20Z3 engine for Swift 014 and 016 chassis consolidated to single spec line with 1350 lbs minimum weight. · FA Swift 014 Mazda MZR 2.0 piston minimum weight drops from 320g to 280g; maximum dome height limit removed. · STU wing assembly wording corrected: no part may be higher than roof height. · STU Nissan SR20DET removes -2mm penalty from Table B. · STU allows alternate intake manifolds on case-by-case basis; stock throttle device and manifold otherwise required. · FA Line N minimum weight raised to 1375 lbs. · STU aftermarket side skirts now allowed if they meet 3-inch ride height, lack ducts except jacks or exhaust, don't exceed fascia width, stay below door bottom, and don't reinforce chassis. · STU wheel flare wording clarified: each fender may be flared to 2" with 1% weight penalty, maintaining OEM profile. · FA cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs. · STL and STU ride height measurement clarified: lowest rocker panel point without driver, excluding pinch weld. · STU Mazda 13B Bridge Port now permits ELITE ROTARY SHOP FD V2.0 intake manifold; stock throttle body requirement removed. · STU Mazda MZR gains alternate Goodwin intake manifold option with stock or Acura throttle body. · STU alternate suspension components rule moved from section E to section D. · STU Honda/Acura B20 now permits B16 or B18 VTEC cylinder head and matching intake manifold. · STU flared fenders up to 2" with 1% weight penalty moved from base to Advanced Aero. · STU Honda Civic Si TCA 2017- requires 37mm TIR throttle as of June 1, 2019. · STU BMW S54B32 OEM classified separately from E46, displacement 3246 cc, minimum weight 3300 lbs, OEM engine mandatory. · FA Formula 3 car transmission rules clarified: up to 6 forward gears, limited-slip differential, sequential removed, 25 lb penalty deleted. · SM fuel pump and filter now permitted as Mazda or OEM equivalent part. · Honda Civic Si 2017- added to STU with 1500cc displacement, 2800 lbs minimum weight, OEM engine and bodywork, specific HPD parts allowed. · STU BMW E46 S54 OEM 3246cc added at 3300 lbs minimum; no Super Touring allowances, OEM intake and cams, 1mm overbore, compression +0.5 permitted. · STU Mazda 13B and 13B Bridge Port may use 13B RE or REW housings and intake with turbo removed. · STU Honda K24 may use intake part numbers 17100-RRB-A00 or 17100-PRB-A10. · STU Mazda 12A Bridge Port added, minimum weight 2550 lbs, Nikki or Auto-type carburettor with specified modifications. · STU World Challenge car weight rule deleted; no replacement specified. · STU AWD/RWD cars no longer must reduce restrictor 1 mm from table. · STU rear wing maximum 12" cord, 72 sq in end plates each, roof height max, body width limit. · FA Swift 014-Mazda MZR 2.0 engine no longer sealed by Elite Engines; block, crank, rods, head, cams, manifold now specified with part numbers and dimensions. · FA Swift 016 Mazda 2.3 and 2.5 liter minimum weight increases 30 lbs to 1450. · SM allows factory Mazda ECU and injector harnesses (P/N 0000-10-020E-99, 0000-10-080D-99) on 1999–2000 model year cars, unmodified. · SM electrical rules reorganized and clarified; alternator now externally regulated only by OEM ECU or master kill switch; harness repair by splicing permitted. · SM tire tread protrusion language removed from GCR 9.1.7.C.5. · STU adds Honda K20C1 Turbo I4, 1996 cc, 3025 lbs minimum weight, 36mm TIR required.showhide
FA Follow up to Letter #27344 on Honda Powered FA Rules #27363removedremovedFA Honda Civic K20Z3 engine for Swift 014 and 016 chassis consolidated to single spec line with 1350 lbs minimum weight.
FA Swift 014 Mazda MZR 2.0 E&O #27305enginefasterengineFA Swift 014 Mazda MZR 2.0 piston minimum weight drops from 320g to 280g; maximum dome height limit removed.
STU Request to correct E&O advanced aerodynamics #27290wordingwordingSTU wing assembly wording corrected: no part may be higher than roof height.
STU Remove -2mm penalty from SR20DET Nissan #26982enginefasterengineSTU Nissan SR20DET removes -2mm penalty from Table B.
STU Request clarification for manifold and throttle in STU #27004wordingwordingSTU allows alternate intake manifolds on case-by-case basis; stock throttle device and manifold otherwise required.
FA Adjust Line N restrictor size and minimum weight #26691weight +30 lbsslowerweightFA Line N minimum weight raised to 1375 lbs.
STU Request to clarify afterrmarket side skirts exhaust exit #26814aeroaddedaeroSTU aftermarket side skirts now allowed if they meet 3-inch ride height, lack ducts except jacks or exhaust, don't exceed fascia width, stay below door bottom, and don't reinforce chassis.
STU Wheel Flare wording #26872wordingwordingSTU wheel flare wording clarified: each fender may be flared to 2" with 1% weight penalty, maintaining OEM profile.
FA Add data plate requirement #26707otheraddedFA cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors and Runoffs.
STU Request Ride Height Clarification #26597wordingwordingSTL and STU ride height measurement clarified: lowest rocker panel point without driver, excluding pinch weld.
STU Request to Use Japanese Mazda 13b Intake Manifold #25790engineaddedengineSTU Mazda 13B Bridge Port now permits ELITE ROTARY SHOP FD V2.0 intake manifold; stock throttle body requirement removed.
STU Request Alternate Intake for Mazda MZR In a Rear Wheel Drive App. #26352inductionaddedinductionSTU Mazda MZR gains alternate Goodwin intake manifold option with stock or Acura throttle body.
STU E&O Suspension #26424wordingwordingSTU alternate suspension components rule moved from section E to section D.
STU Revisit B20 VTEC #26530engineaddedengineSTU Honda/Acura B20 now permits B16 or B18 VTEC cylinder head and matching intake manifold.
STU Move Flared Fenders to STU Advanced Aero #26564aeroaeroSTU flared fenders up to 2" with 1% weight penalty moved from base to Advanced Aero.
STU TCA Civic SI E&O #26606inductionslowerinductionSTU Honda Civic Si TCA 2017- requires 37mm TIR throttle as of June 1, 2019.
STU S54 Spec line #26620cars addedcars addedSTU BMW S54B32 OEM classified separately from E46, displacement 3246 cc, minimum weight 3300 lbs, OEM engine mandatory.
FA Request to add FA engine spec lines #26183wordingwordingFA Formula 3 car transmission rules clarified: up to 6 forward gears, limited-slip differential, sequential removed, 25 lb penalty deleted.
SM Request to allow aftermarket fuel filters. #26370otheraddedSM fuel pump and filter now permitted as Mazda or OEM equivalent part.
STU Request to Class Assignment for 2017 Civic #24287cars addedaddedHonda Civic Si 2017- added to STU with 1500cc displacement, 2800 lbs minimum weight, OEM engine and bodywork, specific HPD parts allowed.
STU Request to run E46 3246cc in STU #25126cars addedaddedSTU BMW E46 S54 OEM 3246cc added at 3300 lbs minimum; no Super Touring allowances, OEM intake and cams, 1mm overbore, compression +0.5 permitted.
STU Engine Classification for Rotary #25564engineaddedengineSTU Mazda 13B and 13B Bridge Port may use 13B RE or REW housings and intake with turbo removed.
STU K24/K20 Head Swap Clarification/Amendment #25899otheraddedSTU Honda K24 may use intake part numbers 17100-RRB-A00 or 17100-PRB-A10.
STU Request to Classify 12a Bridge Ported Rotary Engine #25985cars addedaddedSTU Mazda 12A Bridge Port added, minimum weight 2550 lbs, Nikki or Auto-type carburettor with specified modifications.
STU World Challenge Car Eligibility #26387wordingunclearSTU World Challenge car weight rule deleted; no replacement specified.
STU Request a phone call for discussion regarding weight #26398inductionfasterinductionSTU AWD/RWD cars no longer must reduce restrictor 1 mm from table.
STU Advanced Aero E&O #26413aeroaddedaeroSTU rear wing maximum 12" cord, 72 sq in end plates each, roof height max, body width limit.
FA FA MZR 2.0 Engine Specification #25814engineengineFA Swift 014-Mazda MZR 2.0 engine no longer sealed by Elite Engines; block, crank, rods, head, cams, manifold now specified with part numbers and dimensions.
FA FA 016 weight increase #26063weightslowerweightFA Swift 016 Mazda 2.3 and 2.5 liter minimum weight increases 30 lbs to 1450.
SM Request 99-00 replacement Wire harnesses #25602otheraddedSM allows factory Mazda ECU and injector harnesses (P/N 0000-10-020E-99, 0000-10-080D-99) on 1999–2000 model year cars, unmodified.
SM Organize and Clarify 9.1.7.C.1.o. #25913wordingwordingSM electrical rules reorganized and clarified; alternator now externally regulated only by OEM ECU or master kill switch; harness repair by splicing permitted.
SM Strike Tire Tread Language #26123wordingremovedSM tire tread protrusion language removed from GCR 9.1.7.C.5.
STU Request to Equalize Direct Injected Turbo Cars #24890cars addedaddedSTU adds Honda K20C1 Turbo I4, 1996 cc, 3025 lbs minimum weight, 36mm TIR required.
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 STU'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.