Lap times across years say as much about the weather as the class. % of STL is each class's best lap as a share of STL's on the same day, so the conditions drop out: 100% is level, less is quicker, and a move in it is the class getting faster or slower against the field.
Quickest here:STL 1:35.439 John Schmitt, Runoffs 2016 qualifying · SM 1:40.514 Justin Hille, Runoffs 2016 qualifying · STU 1:19.234 Franklin Church, Runoffs 2018 qualifying · T2 1:31.563 Preston Calvert, Runoffs 2016 qualifying
STLSMSTUT2solid race · dashed qualifying · slower is lower
STLSMSTUT2solid race · dashed qualifying · each class's best lap as a share of STL's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker
2:30.537Derek Ketchie · fastest of 16 · top 5 within 2.9s-1.528s (-1.00%)
2:30.657Danny Steyn · fastest of 16 · top 5 within 0.6s-1.470s (-0.97%)
134.8Mike Taylor+2.6 mph (+2.0%)
2:42.173Brett 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%)
+12.068squal +11.636s
108.0%qual 107.7%
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%)
-4.241squal -5.625s
97.2%qual 96.3%
2:23.977Scotty B White · fastest of 22 · top 5 within 2.5s+0.626s (+0.44%)
2:23.141Scotty B White · fastest of 18 · top 5 within 2.7s-0.342s (-0.24%)
147.2Ami Wilson-6.9 mph (-4.5%)
-7.516squal -6.560s
95.0%qual 95.6%
47 rule changes (STL: 4, SM: 2, STU: 15, T2: 26)10 cars added · 9 weight · 4 induction · 3 engine · 3 tyres & wheels · 2 aero · 2 suspension & brakes · 1 removed · 10 wording · 3 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%. · T2-TCR all models gain 300 lbs minimum weight; splitter ride height 3.50 inches, chassis 4.0 inches. · SM/SMX Mazda rear toe link part number revised from 0000-04-5361426 to 0000-04-5361. · STL removes Mazda MX-5 Cup entirely; renames Spec MX5 Challenge to Spec MX5; renames Global Cup to MX-5 Cup (16-18); removes Global Cup (2019). · 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. · T2-TCR adds 2023 Hyundai Veloster N TCR and Elantra N TCR, both SEQ transmission, 90% power level, 3000 lbs minimum weight. · STL, STU weight calculation procedure clarified: positive percentages added first, negative subtracted second, then fixed weights applied. · 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. · T2 2015–2023 Ecoboost Mustang restrictor removed, tyres to 315, weight cut 100 lbs to 3300. · T2 Chevrolet Corvette C6 Coupe/Grand Sport gains permission for OEM C6 ZR1 and Z06 carbon splitter and spoiler dimensions. · T2-TCR Mazda 3 tyres capped at 275 section width; splitter, valance, ride height rules removed; TCR regulations source simplified. · 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. · STL adds Mazda BP 1.6, 1600cc, minimum weight 2160 lbs. · 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. · T2 BMW 435i brakes increased to 370mm front and 345mm rear from 340mm and 330mm. · T2 Porsche Cayman S year ranges and displacement specs adjusted for 2026 Atlanta HST. · T2 TCR cars must conform to 2024 TCR Technical Regulations; wheel size capped at 10" x 18", tyres at 275 max width. · STU Mazda MZR engines may now use Fab 9 Elite NC MX5 Performance Intake manifold as alternative option. · T2 BMW M235iR removes alternative tune permission. · BMW 435i 2014–2017 added to T2 at 2979 cc, 40mm restrictor, 3400 lbs minimum weight. BMW M235i restrictor clarified to 40mm TIR. · Nissan Z including Nismo added to T2 with 2997cc, 38mm restrictor, 19in wheels, 3600–3650 lbs, 355–381mm brakes. · T2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously only spherical bearings permitted. · T2-TCR adds Link & Co 03 TCR and MG6 TCR at 3000 lbs, 90% power, sequential, 275 max tyre width. · STL minimum weights increase across all engine sizes, 1300cc to 1850cc up to 195–250 lbs. · 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. · T2, T3, T4 now allow under-dash electronics relocation for access after roll cage installation. · T2 Cadillac CT4-V Blackwing minimum weight drops 50 lbs to 3750. · T2 C6 Corvette LS2 restrictor increases from 67mm to 80mm FPR. · T2 Dodge Viper SRT10 coupe 03-06 minimum weight cut 25 lbs to 3650. · T2 Mustang GT 5.0L gains Ford Track/Performance Package rear spoiler aero parts. · T4 Performance clarified: 1-piece alternative rotors permitted only at sizes listed in spec line; alternate brake kits may use matching 1-piece rotors. · 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. · T2 Ford Mustang Boss 302 restrictor opens 56mm to 63mm; Mustang GT 5.0L opens 60mm to 65mm. · T2 Chevrolet Camaro SS/1LE (10-15) minimum weight cut 50 lbs to 3575. · T2 Ford Mustang Challenge Dark Horse R gains 81cc to 5038, weighs 50 lbs more at 3825, runs 315 tyres instead of 295. · STU Honda K24 engine swap weight increases by 2 percent, effective November 1, 2025. · T3 and T4 Mazda MX-5 Miata add permitted gearset kit PT#0000-02-6100 to Notes. · T4 MX-5 Miata 19-24 and 16-18, T3 MX-5 16-18 and Global Cup ND1/ND: discontinued DG Motorsports hardtop part #0000-07-5901 removed from permitted list. · T2 Spec Corvette rev limit set to 7100 rpm.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%.
T2 TCR Data Points - BoP #40508weight +300 lbsslower · weightT2-TCR all models gain 300 lbs minimum weight; splitter ride height 3.50 inches, chassis 4.0 inches.
SM Rear Toe Link #40271wordingwordingSM/SMX Mazda rear toe link part number revised from 0000-04-5361426 to 0000-04-5361.
STL Spec Line Clean Up #40344cars addedremoved · cars addedSTL removes Mazda MX-5 Cup entirely; renames Spec MX5 Challenge to Spec MX5; renames Global Cup to MX-5 Cup (16-18); removes Global Cup (2019).
STU 9” Wheels #40433tyres & wheelsslower · tyres & 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 #40474weightslower · weightSTU GT3U minimum weight increases from GT3 race weight plus 225 to plus 275 pounds; 2.0L unrestricted engines add 75 lbs.
T2 2023 TCR Hyundais #40278cars addedaddedT2-TCR adds 2023 Hyundai Veloster N TCR and Elantra N TCR, both SEQ transmission, 90% power level, 3000 lbs minimum weight.
STL Calculating Weight #40224wordingwordingSTL, STU weight calculation procedure clarified: positive percentages added first, negative subtracted second, then fixed weights applied.
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.
T2 C6 Corvette - All Body Trims Requested #40174aeroadded · aeroT2 Chevrolet Corvette C6 Coupe/Grand Sport gains permission for OEM C6 ZR1 and Z06 carbon splitter and spoiler dimensions.
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 #39872inductionremoved · inductionSTU eliminates 33 and 34 mm inlet restrictor options, removing minimum weights of 2380 and 2525 lbs.
T2 14-17 BMW 435i Brake Approval Request #39910suspension & brakessuspension & brakesT2 BMW 435i brakes increased to 370mm front and 345mm rear from 340mm and 330mm.
T2 Porsche Cayman S Spec Lines Needed for Atlanta HST #39947wordingwordingT2 Porsche Cayman S year ranges and displacement specs adjusted for 2026 Atlanta HST.
T2 Please address loopholes in T2 TCR #40002wordingwordingT2 TCR cars must conform to 2024 TCR Technical Regulations; wheel size capped at 10" x 18", tyres at 275 max width.
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.
T2 BMW 240i Permitted Tune #39861wordingremovedT2 BMW M235iR removes alternative tune permission.
T2 Request to Add 2014-2017 435i to T2 #38991cars addedaddedBMW 435i 2014–2017 added to T2 at 2979 cc, 40mm restrictor, 3400 lbs minimum weight. BMW M235i restrictor clarified to 40mm TIR.
T2 Consideration for Nissan Z & NISMO Z to Touring 2 Class #39296cars addedaddedNissan Z including Nismo added to T2 with 2997cc, 38mm restrictor, 19in wheels, 3600–3650 lbs, 355–381mm brakes.
T2 Allow Alt Bushing Material in Toe Links #39607suspension & brakesadded · suspension & brakesT2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously only spherical bearings permitted.
T2 Request for Classification of MG6 TCR in T2-TCR Class #39702cars addedaddedT2-TCR adds Link & Co 03 TCR and MG6 TCR at 3000 lbs, 90% power, sequential, 275 max tyre width.
STL Weight adjustment for STL #39579weightslower · weightSTL minimum weights increase across all engine sizes, 1300cc to 1850cc up to 195–250 lbs.
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.
T2 Alternate Placement of Fuse Panel and Electronics Request #39370otheraddedT2, T3, T4 now allow under-dash electronics relocation for access after roll cage installation.
T2 Clarify T4 Brake Rotor Allowance #39503wordingwordingT4 Performance clarified: 1-piece alternative rotors permitted only at sizes listed in spec line; alternate brake kits may use matching 1-piece rotors.
STU Turbo Inlet Restrictor Table #38961wordingwordingSTU 36mm restrictor revised to 2830 cc, 37mm to 2980 cc.
STU 275 Tire Rule #38983tyres & wheelsslower · tyres & 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 #39375weightfaster · weightSTU Honda K20 and K24 engines lose 2% weight penalty; minimum weight now per chart only.
T2 Help the 2011-2014 s197Mustang GT and Boss302 Less Restriction #38523enginefaster · engineT2 Ford Mustang Boss 302 restrictor opens 56mm to 63mm; Mustang GT 5.0L opens 60mm to 65mm.
T2 Improving Competitiveness of Gen 5 Camaro SS #39021weight -50 lbsfaster · weightT2 Chevrolet Camaro SS/1LE (10-15) minimum weight cut 50 lbs to 3575.
T2 Adjust T2 Darkhorse R #39346engineslower · engineT2 Ford Mustang Challenge Dark Horse R gains 81cc to 5038, weighs 50 lbs more at 3825, runs 315 tyres instead of 295.
STU Non-Homologated Engine Swaps - Specifically K24A2 w/ Honda CRZ #38746weightslower · weightSTU Honda K24 engine swap weight increases by 2 percent, effective November 1, 2025.
T2 ND Gearset Request for T4 #39166otheraddedT3 and T4 Mazda MX-5 Miata add permitted gearset kit PT#0000-02-6100 to Notes.
T2 ND Spec Lines Wrong PT#'s #39170removedremovedT4 MX-5 Miata 19-24 and 16-18, T3 MX-5 16-18 and Global Cup ND1/ND: discontinued DG Motorsports hardtop part #0000-07-5901 removed from permitted list.
2:32.065Jose Osiris Pena · fastest of 14 · top 5 within 3.4s+2.002s (+1.33%)
2:32.127Jose Osiris Pena · fastest of 13 · top 5 within 2.4s+1.882s (+1.25%)
132.2Jon Sewell-2.1 mph (-1.5%)
2:43.111Bobby 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%)
+12.303squal +11.046s
108.1%qual 107.3%
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%)
-7.630squal -8.982s
95.0%qual 94.1%
2:23.351Kurt Rezzetano · fastest of 11 · top 5 within 3.1s+1.234s (+0.87%)
2:23.483Kurt Rezzetano · fastest of 10 · top 5 within 2.9s+0.222s (+0.15%)
154.1John Heinricy+4.8 mph (+3.2%)
-8.644squal -8.714s
94.3%qual 94.3%
54 rule changes (STL: 3, SM: 4, STU: 18, T2: 29)10 cars added · 9 weight · 8 engine · 7 tyres & wheels · 2 induction · 1 removed · 11 wording · 6 other · STU Lotus Elise SC and Exige SC weight reduced from 2450 to 2250 lbs. · Lotus Evora GT4 minimum weight drops to 2700 lbs; Elise Cup R to 2250 lbs; Elise SC and Exige SC to 2450–2550 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. · T2, T3, T4 spec table header changed from T2 to ET. · BMW M2 CS Cup 2020-2021 in T2 Spec must run Red power stick part #8324085, not Purple #8324089. · T2 Corvette C5 Z06 and C6 brake allowances simplified to stock specifications only. · T2 Chevrolet Corvette C5 LS1 restrictor reduced from 59mm to 58mm FPR. · 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. · STL Mazda MX5 Challenge minimum weight now references GCR 9.1.7.1; mandatory component spec list removed, alternative tires only allowed. · 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. · T2 C6 Corvette LS2 requires 67mm FPR restrictor, up from 63mm. · T2 Nissan 370Z max wheel size increases from 19×10 to 19×10.5 inches. · T2 Cadillac CT4-V Blackwing tire size maximum increases from 295 to 315. · Ford Mustang Challenge Darkhorse R added to T2 with 4957cc engine, 58mm restrictor, 3650 lbs minimum weight. · T2 350Z Spec Line eliminates detailed part numbers and consolidates allowances into cleaner performance criteria. · 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. · T2 Ford Mustang GT 5.0L (15-23) combined with separate restrictors: 63mm for Gen 2, 60mm for Gen 3; 100 lb weight break removed. · T2 Chevrolet Camaro 1LE 1LE gains 100 lbs to 3600, restrictor opens 58mm to 62mm. · T2 BMW M235iR permitted oil cooler, radiator per touring rules, and silicone charge pipe. · Ford SCCA Club Spec Mustang added to T3 at 3350 lbs; Mazda SCCA Club Spec MX-5 added to T4 at 2500 lbs. · 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. · T2, T3, T4: nine, nine, and thirty-seven expired spec lines removed effective 2025-01-01. · T2 Ford Mustang GT 5.0L 11-14 minimum weight drops 50 lbs to 3525. · T2 Spec Corvette: SC-3200, SC+-3300; Nankang NS-2R or 295 R compound or any 200tw 315 tire; radiator shroud, brakes, shocks, dry sump, battery, differential, springs now permitted. · 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. · 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. · T2, T3 Mustang spec lines remove redundant driveshaft allowance notes across six model year ranges. · T2 Chevrolet Corvette C6 LS3 restrictor increased from 53mm to 56mm flat plate. · T2, T3, T4 fuel cell installations may omit charcoal canisters, emissions valves, and sensors. · T2, T3, T4 brake specifications clarified: 2-piece rotors allowed in T2 within 5% OE diameter, T3 within 2% OEM diameter. · T2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors. · Porsche Spec Boxster moves to T4, minimum weight 2750 lbs, ineligible for Runoffs until 3 Super Tour events. · T2 Corvette C6 front wheel width increases to 11 inches, rear to 11 or 13 inches. · T4 BMW 320i Spec Line: Turner Motorsports intercooler #024703TMS02 now allowed. · 2005 Cadillac CTS 3.6L 6-speed manual classified in T3 Spec. · T2 C5 Corvette restrictors now engine-specific: LS1 59mm, LS2 63mm, LS3 56mm FPR. · T2 Chevrolet Corvette Z06 (06-12) Spec Line deleted entirely. · STU Mini Cooper S SC: 1900 stock pulley spec to 2.565 diameter; 2100 now permits 2.285 diameter pulley. · T2 Spec Corvette now allows 295 R compound DOT tire alternative to required Nankang NS-2R.showhide
STU Lotus Weight Reduction E&O #38919weightfaster · weightSTU Lotus Elise SC and Exige SC weight reduced from 2450 to 2250 lbs.
STL Lotus Weight Reduction #38772weight -50 lbsfaster · weightLotus Evora GT4 minimum weight drops to 2700 lbs; Elise Cup R to 2250 lbs; Elise SC and Exige SC to 2450–2550 lbs.
STU STU-TCR Adjustments #38723weightslower · weightSTU-TCR gains GT3 TCR spec lines; 275 tyre option now costs 150 lb adder, up from 100 lb.
STU Lotus Weight Reduction #38772weight -50 lbsfaster · weightLotus Evora GT4 minimum weight drops to 2700 lbs; Elise Cup R to 2250 lbs; Elise SC and Exige SC to 2450–2550 lbs.
T2 Incorrect Touring Heading #38451wordingwordingT2, T3, T4 spec table header changed from T2 to ET.
T2 Clarifications needed to BMW M2 CS cup line #38536wordingwordingBMW M2 CS Cup 2020-2021 in T2 Spec must run Red power stick part #8324085, not Purple #8324089.
T2 Fix brake allowance supersessions. #38554otherotherT2 Corvette C5 Z06 and C6 brake allowances simplified to stock specifications only.
T2 C5 Corvette correction #38782engineslower · engineT2 Chevrolet Corvette C5 LS1 restrictor reduced from 59mm to 58mm FPR.
STU 2.8-3.2L N/A Engine Allowances #38007tyres & wheelsfaster · tyres & 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 #38422engineadded · engineSTU 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.
STL E&O: SMX Allowance in STL #37945wordingunclearSTL Mazda MX5 Challenge minimum weight now references GCR 9.1.7.1; mandatory component spec list removed, alternative tires only allowed.
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 #38268weightfaster · weightSTU-GT3U minimum weight reduced from plus 250 to plus 225 pounds; wheel and tyre options clarified with weight adjustments.
T2 370Z Mid link Replacement for True Coil Overs and OEM Wheel Size #38014tyres & wheelsfaster · tyres & wheelsT2 Nissan 370Z max wheel size increases from 19×10 to 19×10.5 inches.
T2 T2 Cadillac tire #38210tyres & wheelsfaster · tyres & wheelsT2 Cadillac CT4-V Blackwing tire size maximum increases from 295 to 315.
T2 Please class the Darkhorse R in T2 #37295cars addedaddedFord Mustang Challenge Darkhorse R added to T2 with 4957cc engine, 58mm restrictor, 3650 lbs minimum weight.
T2 T2 350Z Spec Line Cleanup #37603wordingwordingT2 350Z Spec Line eliminates detailed part numbers and consolidates allowances into cleaner performance criteria.
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 #37717inductionfaster · inductionSTU Mini Cooper S SC pulley diameter reduced to 2.185 inches.
STU Question About a Weight Modifier #37782weightfaster · weightSTU Honda K20C1 Turbo I4 exempted from 3% direct injection weight adder.
STU Increase Minimum Weight #37919weight +100 lbsslower · weightSTU GT3U minimum weight increases 150 pounds to 250 pounds.
T2 Mustang Update backdate #37275enginefaster · engineT2 Ford Mustang GT 5.0L (15-23) combined with separate restrictors: 63mm for Gen 2, 60mm for Gen 3; 100 lb weight break removed.
T2 BOP Adjustment for 2016 - Camaro SS/1LE #37434weight +100 lbsfaster · weightT2 Chevrolet Camaro 1LE 1LE gains 100 lbs to 3600, restrictor opens 58mm to 62mm.
T2 BMW M235iR TCS CHANGE REQUEST #37470otheraddedT2 BMW M235iR permitted oil cooler, radiator per touring rules, and silicone charge pipe.
T2 Request to Classify Club Spec in Appropriate Touring Classes #37523cars addedaddedFord SCCA Club Spec Mustang added to T3 at 3350 lbs; Mazda SCCA Club Spec MX-5 added to T4 at 2500 lbs.
STU Audi 1.8t Wagon STU Table B #36685cars addedremoved · cars 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 & wheelsadded · tyres & wheelsSTU GT3 TCR may run 275-wide DOT tires with 100 lb weight penalty; A compound prohibited at 275.
T2 Remove spec lines that have expired #37269removedremovedT2, T3, T4: nine, nine, and thirty-seven expired spec lines removed effective 2025-01-01.
T2 BoP for the Various Mustangs #37185weight -50 lbsfaster · weightT2 Ford Mustang GT 5.0L 11-14 minimum weight drops 50 lbs to 3525.
T2 Spec Corvette Line Clarification. #37441otheraddedT2 Spec Corvette: SC-3200, SC+-3300; Nankang NS-2R or 295 R compound or any 200tw 315 tire; radiator shroud, brakes, shocks, dry sump, battery, differential, springs now permitted.
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.
STL 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 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.
T2 Redundant Verbiage Regarding Mustang Spec Lines for Driveshaft #36484wordingwordingT2, T3 Mustang spec lines remove redundant driveshaft allowance notes across six model year ranges.
T2 Request Less Restriction for Ls-3 Engined C6 Corvette #36810enginefaster · engineT2 Chevrolet Corvette C6 LS3 restrictor increased from 53mm to 56mm flat plate.
T2 Fuel Emissions Components #37076otheraddedT2, T3, T4 fuel cell installations may omit charcoal canisters, emissions valves, and sensors.
T2 fix brake wording #37129wordingwordingT2, T3, T4 brake specifications clarified: 2-piece rotors allowed in T2 within 5% OE diameter, T3 within 2% OEM diameter.
T2 Evaporative emissions systems #37130otheraddedT2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors.
T2 Move Spec Boxster to T4 #37158cars addedaddedPorsche Spec Boxster moves to T4, minimum weight 2750 lbs, ineligible for Runoffs until 3 Super Tour events.
T2 Corvette Wheels #37169tyres & wheelsfaster · tyres & wheelsT2 Corvette C6 front wheel width increases to 11 inches, rear to 11 or 13 inches.
T2 BMW 320i Spec Line #37204engineadded · engineT4 BMW 320i Spec Line: Turner Motorsports intercooler #024703TMS02 now allowed.
T2 Classification for a 2005 Cadillac CTS 3.6 liter 6 speed manual #37224cars addedadded2005 Cadillac CTS 3.6L 6-speed manual classified in T3 Spec.
T2 Please Consider Allowing Update to the C5 Corvette #37298engineunclearT2 C5 Corvette restrictors now engine-specific: LS1 59mm, LS2 63mm, LS3 56mm FPR.
T2 Major error in lane, but nobody ran it. #37302cars addedremoved · cars addedT2 Chevrolet Corvette Z06 (06-12) Spec Line deleted entirely.
STU R53 15% Pulley Request #36980enginefaster · engineSTU Mini Cooper S SC: 1900 stock pulley spec to 2.565 diameter; 2100 now permits 2.285 diameter pulley.
T2 Spec Corvette Change for T2 #37127tyres & wheelsadded · tyres & wheelsT2 Spec Corvette now allows 295 R compound DOT tire alternative to required Nankang NS-2R.
2:30.063Joe Moser · fastest of 18 · top 5 within 3.7s-1.357s (-0.90%)
2:30.245Joe Moser · fastest of 16 · top 5 within 4.2s-1.870s (-1.23%)
134.3Joe Moser+1.3 mph (+1.0%)
2:41.106Ethan 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%)
+11.241squal +11.043s
107.5%qual 107.4%
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%)
-4.421squal -3.836s
97.1%qual 97.4%
2:22.117Kurt Rezzetano · fastest of 8 · top 5 within 2.7s-2.078s (-1.44%)
2:23.261Kurt Rezzetano · fastest of 7 · top 5 within 3.0s-3.542s (-2.41%)
149.3Scotty B White+2.0 mph (+1.3%)
-6.984squal -7.946s
95.4%qual 94.7%
43 rule changes (STL: 4, SM: 4, STU: 4, T2: 31)10 weight · 6 cars added · 5 engine · 4 aero · 4 suspension & brakes · 3 tyres & wheels · 2 induction · 6 wording · 3 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. · T2 Subaru Impreza WRX STi (03-07) and (08-11) expiry notes removed, appeal deadline lifted. · T2 Ford Mustang S550 5.0L gains 100 lb weight allowance with 4-piston stock or Brembo 355mm brakes; Ecoboost 2.3 brake weight allowance removed. · T2 Mustang GT 5.0L 15-17 and 2018- now permit Track/Performance Package parts; T3 V6 15-17 clarified to allow Track/Performance package. · T2 Ford Mustang S550 5.0 Gen2/Gen3 loses 100 lbs with 4-piston stock or Brembo brakes, 355mm rotors. · T2-T4 Ford Mustangs: remove 25 lb penalty for non-OEM driveshaft, clarify alternate driveshaft allowance. · T2 Camaro SS, Camaro 1LE, Corvette C5, C6, Z06, Firebird, Solstice GXP now allow four or six piston front calipers. · Audi S4 (2000–2002) classified in T3 with 2671cc, 3400 lbs minimum weight, 38mm restrictor, allowing 800lb springs and intercooler. · T3 and T4 Mazda RX-8 may remove or disable factory oil injection system. · T2 BMW M3 01-06 maximum wheel size increases from 18 x 9 to 18 x 10 inches. · T2, T3, T4 driveshafts may use carbon fiber, aluminum, or steel; two-piece replaced with one-piece; non-OEM adds 25 lbs. · T2 Porsche Cayman S 06-09 adds StopTech ST60/ST40 brake kit option with 50 lb weight penalty. · 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. · T2, T3, T4 Spec Lines remove wheelbase requirement, add Required Restrictor specification. · T2 and T3 Nissan 370Z front brake rotors increase to 355×32 mm, rears to 350×20 mm. · T2 2018+ Mustang GT 5.0L gains BMR rear upper control arm camber links part #UTCA064. · STL and STU now permit electric power steering pumps, OEM electric-assisted steering, or column-mounted electric steering assist systems. · STL normally aspirated minimum weights reduced: 1900cc to 2540 lbs, 1950cc to 2583 lbs, 2000cc to 2625 lbs; short-wheelbase FWD adds 1.25%; Honda B16/B17/B18C1 throttle to 51mm, B18C Type R and Mazda MZR to 50mm. · STL Mazda 12A: 5th and 6th intake port actuators and valves may no longer be removed or disabled. · STL and STU now permit electric power steering pumps, OEM electric-assisted steering, or column-mounted electric steering assist systems. · T2 Ford Mustang GT 5.0L 15-17 permits BMR rear upper control arm camber links part #UTCA064. · T2 Camaro SS, 1LE, Corvette C5, C6, Z06, Firebird, Solstice GXP now allow four or six piston front calipers. · T2 Cadillac CT4-V Blackwing Runoffs eligibility requirement removed. · T2, T3, T4 battery replacement no longer allows alternate manufacturer batteries within 10% OEM weight. · T4 now allows C-Spec touring cars to compete, in addition to existing B-Spec eligibility. · T2, T3, T4 spec lines expire 12/31/24; submit to appeal or cars are removed from class. · T2 Chevrolet Camaro 1LE minimum weight rises to 3575 lbs; restrictor grows to 60mm flat plate. · STL 79-85 RX7 12A now allows auto-type 2 bbl carburetor with 42mm choke on dual-y manifold, not just stock Nikki. · T2 Cadillac CT4-V Blackwing rear wheels widen from 18 x 10 to 18 x 11; sway bars now allowed 35mm front, 30mm rear. · T2 BMW M2 CS Cup minimum weight cut 50 lbs to 3550; M235iR cut 50 lbs to 3300. · T2 Spec Corvette weight drops 175 lbs to 3200; restrictor and ride height requirements removed; Nankang NS-2R tyres now mandatory. · T2 Dodge Viper SRT-10 rear tyre shrinks to 335/30 from 345/30. · T2 Ford Mustang GT 5.0L (11-14) gains 75 lbs to 3575; (15-17) gains 50 lbs to 3650; (18+) gains 50 lbs to 3650. Restrictors enlarged. · T2 Chevrolet Camaro 1LE minimum weight drops to 3500 lbs, restrictor plate increases to 58mm flat. · T2 C5 Z06 gains 56mm restrictor spec; C6 LS2 restrictor opens to 63mm, LS3 to 53mm. · T3 Nissan 370Z now includes model years 2009–2022 with Nismo editions. · T2 BMW M2 CS Cup 2020- gains permission for hood vents conforming to 9.1.9.2.D.8.a.7.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 #36556engineadded · engineSM 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 #36255inductionfaster · inductionSTU RWD turbo cars no longer required to reduce inlet restrictor by 1 mm from table minimum.
T2 Subaru Appeal #36258wordingwordingT2 Subaru Impreza WRX STi (03-07) and (08-11) expiry notes removed, appeal deadline lifted.
T2 S550 Brakes #36571weightslower · weightT2 Ford Mustang S550 5.0L gains 100 lb weight allowance with 4-piston stock or Brembo 355mm brakes; Ecoboost 2.3 brake weight allowance removed.
T2 Mustang T2/T3 #35877cars addedaddedT2 Mustang GT 5.0L 15-17 and 2018- now permit Track/Performance Package parts; T3 V6 15-17 clarified to allow Track/Performance package.
T2 S550 Brakes #35926weightfaster · weightT2 Ford Mustang S550 5.0 Gen2/Gen3 loses 100 lbs with 4-piston stock or Brembo brakes, 355mm rotors.
T2 T2-T4 Driveshaft Mistake...? #36050weightfaster · weightT2-T4 Ford Mustangs: remove 25 lb penalty for non-OEM driveshaft, clarify alternate driveshaft allowance.
T2 request for allowance of 6 piston calipers for T2 C5 corvettes #36126suspension & brakesadded · suspension & brakesT2 Camaro SS, Camaro 1LE, Corvette C5, C6, Z06, Firebird, Solstice GXP now allow four or six piston front calipers.
T2 B8/8.5 Audi S4 T3 and T2 #36195cars addedaddedAudi S4 (2000–2002) classified in T3 with 2671cc, 3400 lbs minimum weight, 38mm restrictor, allowing 800lb springs and intercooler.
T2 Allow T4 and T3 RX8 to Disable/Remove Factory Oil Inj. #35761engineadded · engineT3 and T4 Mazda RX-8 may remove or disable factory oil injection system.
T2 Competition Adjustment Request/Wheel Size of E46 #35895tyres & wheelsfaster · tyres & wheelsT2 BMW M3 01-06 maximum wheel size increases from 18 x 9 to 18 x 10 inches.
T2 Driveshafts #35916weightslower · weightT2, T3, T4 driveshafts may use carbon fiber, aluminum, or steel; two-piece replaced with one-piece; non-OEM adds 25 lbs.
T2 Brake Request for 2009 Porsche Cayman #35723cars addedaddedT2 Porsche Cayman S 06-09 adds StopTech ST60/ST40 brake kit option with 50 lb weight penalty.
STU Letter #35397 addendum #35453aeroadded · aeroSTU 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.
T2 370Z Brake Rotor Size Correction #35487suspension & brakessuspension & brakesT2 and T3 Nissan 370Z front brake rotors increase to 355×32 mm, rears to 350×20 mm.
T2 Letter #35154 2018+ Mustang GT Expansion #35488suspension & brakesadded · suspension & brakesT2 2018+ Mustang GT 5.0L gains BMR rear upper control arm camber links part #UTCA064.
STL ST Electric-Assisted Steering Systems #35066aeroadded · aeroSTL and STU now permit electric power steering pumps, OEM electric-assisted steering, or column-mounted electric steering assist systems.
STL BOP Adjustments #35112weightfaster · weightSTL normally aspirated minimum weights reduced: 1900cc to 2540 lbs, 1950cc to 2583 lbs, 2000cc to 2625 lbs; short-wheelbase FWD adds 1.25%; Honda B16/B17/B18C1 throttle to 51mm, B18C Type R and Mazda MZR to 50mm.
STL Mazda 12A #35320engineremoved · engineSTL Mazda 12A: 5th and 6th intake port actuators and valves may no longer be removed or disabled.
STU ST Electric-Assisted Steering Systems #35066aeroadded · aeroSTL and STU now permit electric power steering pumps, OEM electric-assisted steering, or column-mounted electric steering assist systems.
T2 2015+ Mustang Sway Bar and A-Arm Request #35154suspension & brakesadded · suspension & brakesT2 Ford Mustang GT 5.0L 15-17 permits BMR rear upper control arm camber links part #UTCA064.
T2 Brake Kits #35245cars addedaddedT2 Camaro SS, 1LE, Corvette C5, C6, Z06, Firebird, Solstice GXP now allow four or six piston front calipers.
T2 Runoffs wording on Caddy in T2 #35377wordingaddedT2 Cadillac CT4-V Blackwing Runoffs eligibility requirement removed.
T2 More Car Lightening Stuff #35319wordingremovedT2, T3, T4 battery replacement no longer allows alternate manufacturer batteries within 10% OEM weight.
T2 Inclusion of B-C spec cars in T4 #35374cars addedaddedT4 now allows C-Spec touring cars to compete, in addition to existing B-Spec eligibility.
T2 T2-T4 Set expiration dates on spec lines #35378wordingremovedT2, T3, T4 spec lines expire 12/31/24; submit to appeal or cars are removed from class.
T2 Reply to letter #35161 and #31661 #35384weight +75 lbsslower · weightT2 Chevrolet Camaro 1LE minimum weight rises to 3575 lbs; restrictor grows to 60mm flat plate.
STL Alternate Carburetor Request for 79-85 RX7 12a #35181engineadded · engineSTL 79-85 RX7 12A now allows auto-type 2 bbl carburetor with 42mm choke on dual-y manifold, not just stock Nikki.
T2 Rebalance Blackwing Cadillac T2 #35079tyres & wheelsfaster · tyres & wheelsT2 Cadillac CT4-V Blackwing rear wheels widen from 18 x 10 to 18 x 11; sway bars now allowed 35mm front, 30mm rear.
T2 M2 CS RACING #35130weight -50 lbsfaster · weightT2 BMW M2 CS Cup minimum weight cut 50 lbs to 3550; M235iR cut 50 lbs to 3300.
T2 Spec Corvette in T2 #35139weight -175 lbsfaster · weightT2 Spec Corvette weight drops 175 lbs to 3200; restrictor and ride height requirements removed; Nankang NS-2R tyres now mandatory.
T2 T2 Viper BoP #35155tyres & wheelsslower · tyres & wheelsT2 Dodge Viper SRT-10 rear tyre shrinks to 335/30 from 345/30.
T2 BOP Adjustment for 5.0L Mustangs #35156weight +75 lbsslower · weightT2 Ford Mustang GT 5.0L (11-14) gains 75 lbs to 3575; (15-17) gains 50 lbs to 3650; (18+) gains 50 lbs to 3650. Restrictors enlarged.
T2 Take at Look at T-2 BOP #35161weight -50 lbsfaster · weightT2 Chevrolet Camaro 1LE minimum weight drops to 3500 lbs, restrictor plate increases to 58mm flat.
T2 C5 Corvette Spec Line Oversight #35169enginefaster · engineT2 C5 Z06 gains 56mm restrictor spec; C6 LS2 restrictor opens to 63mm, LS3 to 53mm.
T2 Requested Update of Model Years of 370Z #35231cars addedaddedT3 Nissan 370Z now includes model years 2009–2022 with Nismo editions.
T2 M2 CS RACING #35122aeroadded · aeroT2 BMW M2 CS Cup 2020- gains permission for hood vents conforming to 9.1.9.2.D.8.a.7.
2:05.779Danny Steyn · fastest of 22 · top 5 within 3.4s+0.305s (+0.24%)
2:06.682Joe Moser · fastest of 20 · top 5 within 1.5s-1.150s (-0.90%)
131.8Danny Steyn+0.1 mph (+0.1%)
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%)
+9.547squal +9.207s
107.5%qual 107.3%
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%)
-4.380squal -5.390s
96.5%qual 95.7%
1:59.504Kurt Rezzetano · fastest of 13 · top 5 within 2.1s-0.772s (-0.64%)
2:01.201Kurt Rezzetano · fastest of 13 · top 5 within 1.6s-3.555s (-2.85%)
150.7Scotty B White-1.9 mph (-1.2%)
-5.481squal -6.275s
95.7%qual 95.0%
23 rule changes (STL: 2, SM: 1, STU: 3, T2: 17)5 suspension & brakes · 4 cars added · 4 weight · 3 engine · 1 aero · 1 tyres & wheels · 3 wording · 2 other · T2 Chevrolet Corvette C6 LS2 restrictor plate increases from 58mm to 60mm flat plate. · T2 Cadillac CT4-V Blackwing permitted to use Radium fuel surge tank with fireproof bulkhead requirement. · Mazda RX-8 T3 and T4 transmission and final drive pairing requirement removed; T4 gains Mazdaspeed radiator, spring kit, restrictor, spoiler, air dam. · T3 BMW 320i 14–15 gains aftermarket intercooler; T4 BMW 320i 14–15 loses it. · T3 and T2 Pontiac Solstice GXP 07-09 minimum ride height set to 3 inches. · STU adds 2022 Toyota GR Cup and GR86 Cup, both 2387cc, 2700 lbs, 18-inch wheels, 245/620R18 slicks. · 370Z T2 suspension notes clarified: sway bars now 35mm front/29mm rear, SPL rear toe arms removed, NISMO alternatives added to camber/traction arms and mid-link. · STL ITA and ITS RX7, and ITS/ITA/ITB/ITC 1985+ models clarified to require tires per 9.1.4.2. · T2 Porsche Cayman S year range extended from 06-08 to 06-09. · T2 C5 Z06 with 56mm restrictor weighs 3425 lbs; 58mm restrictor option removed. · STU Mazda BP5A now classified at 1839 cc displacement, 2510 lbs minimum weight, alternate intake manifold permitted. · T2 upper and lower control arm bushings can now use polyurethane, delrin, or alternate synthetic material. · T2 Cadillac CT4-V Blackwing now permits adjustable sway bar end links. · STU minimum weights adjusted: 2450 cc to 2595 lbs, 2600 cc to 2710 lbs. · T2 Honda Civic Type-R tire width increases from 275 to 295. · T2 C5 Corvette gains GM Motorsports T1 suspension package and SpecCorvette SCT-1 swaybars. · T2 and T3 Mustang 11-14 may remove upper grille fog lights, replace with mesh or screen. · SM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore. · Spec MX5 in STL allows ACT clutch 0000-02-5004-G6, wheels 17x8, Toyo RR and RA1 235-40-17 tyres, or alternatives on 17x7 per rules. · T2 BMW M235iR minimum weight drops 50 lbs to 3350; aftermarket T2 compliant shocks now allowed. · T5 touring class added; T2-T5 cars may race one class up; T5 maximum tyre width 225 with minimum aspect ratio 45. · T2-T5 Touring front and rear suspension maximum negative camber clarified to 3.5 degrees. · T2 Dodge Viper SRT-10 rear wheel widens to 19 x 13, weight increases to 3675 lbs, throttle restrictor hole enlarged to 44mm convertible or 42mm hardtop.showhide
T2 Corvette LS2 Restrictor Plate Adjustment #34456enginefaster · engineT2 Chevrolet Corvette C6 LS2 restrictor plate increases from 58mm to 60mm flat plate.
T2 Blacking Cadillac Fuel Capacity #34624otheraddedT2 Cadillac CT4-V Blackwing permitted to use Radium fuel surge tank with fireproof bulkhead requirement.
T2 Rules Clarification for Mazda RX8 Spec Line #34395wordingwordingMazda RX-8 T3 and T4 transmission and final drive pairing requirement removed; T4 gains Mazdaspeed radiator, spring kit, restrictor, spoiler, air dam.
T2 rule book corrections #34437otheraddedT3 BMW 320i 14–15 gains aftermarket intercooler; T4 BMW 320i 14–15 loses it.
T2 Ride Height Correction for the T3 Solstice. #34615suspension & brakessuspension & brakesT3 and T2 Pontiac Solstice GXP 07-09 minimum ride height set to 3 inches.
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.
T2 370Z Obsolete Parts & NISMO Alternatives to SPL Parts #34297suspension & brakessuspension & brakes370Z T2 suspension notes clarified: sway bars now 35mm front/29mm rear, SPL rear toe arms removed, NISMO alternatives added to camber/traction arms and mid-link.
STL Clarify STL table B - IT spec notes on Tires #34187wordingwordingSTL ITA and ITS RX7, and ITS/ITA/ITB/ITC 1985+ models clarified to require tires per 9.1.4.2.
T2 2009 Porsche Cayman Classing Request #34147cars addedaddedT2 Porsche Cayman S year range extended from 06-08 to 06-09.
STU Alternate OEM Miata Intake Manifold #33827engineadded · engineSTU Mazda BP5A now classified at 1839 cc displacement, 2510 lbs minimum weight, alternate intake manifold permitted.
T2 Allowance of any nonmetallic bushing material in T2 #33833suspension & brakesadded · suspension & brakesT2 upper and lower control arm bushings can now use polyurethane, delrin, or alternate synthetic material.
T2 Allow Adjustable stabilizer bar links #33861suspension & brakesadded · suspension & brakesT2 Cadillac CT4-V Blackwing now permits adjustable sway bar end links.
STU E&O STU NA Weight Chart. #33737weightfaster · weightSTU minimum weights adjusted: 2450 cc to 2595 lbs, 2600 cc to 2710 lbs.
T2 Honda Civic Type R Tire Size Increase #33672tyres & wheelsfaster · tyres & wheelsT2 Honda Civic Type-R tire width increases from 275 to 295.
T2 Mustang OEM Grill Request #33333aeroadded · aeroT2 and T3 Mustang 11-14 may remove upper grille fog lights, replace with mesh or screen.
SM BOP for NB1 and NB2 #32309weightslower · weightSM Mazda MX-5 Miata 01-05 minimum weight rises to 2450 lbs, or 2465 with alternate bore.
STL Spec MX5 in STL #33473cars addedaddedSpec MX5 in STL allows ACT clutch 0000-02-5004-G6, wheels 17x8, Toyo RR and RA1 235-40-17 tyres, or alternatives on 17x7 per rules.
T2 BMW M235iR/M240iR Aftermarket 2WNR Shocks Allowed - Touring 2 #33464weight -50 lbsfaster · weightT2 BMW M235iR minimum weight drops 50 lbs to 3350; aftermarket T2 compliant shocks now allowed.
T2 Touring (T2-T5) Category #33617cars addedaddedT5 touring class added; T2-T5 cars may race one class up; T5 maximum tyre width 225 with minimum aspect ratio 45.
T2 ENO 9.1.9.2.D.1.e.1.a. #33651wordingwordingT2-T5 Touring front and rear suspension maximum negative camber clarified to 3.5 degrees.
T2 Heavy Cars #33345engine +125 lbsfaster · engineT2 Dodge Viper SRT-10 rear wheel widens to 19 x 13, weight increases to 3675 lbs, throttle restrictor hole enlarged to 44mm convertible or 42mm hardtop.
2:05.474Danny Steyn · fastest of 24 · top 5 within 2.3s-1.729s (-1.36%)
2:07.832Danny Steyn · fastest of 22 · top 5 within 1.9s+0.559s (+0.44%)
131.7Trever Degioanni-3.2 mph (-2.3%)
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%)
+11.275squal +9.190s
108.8%qual 107.3%
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%)
+24.525squal -4.859s
119.2%qual 96.1%
2:00.276Kurt Rezzetano · fastest of 14 · top 5 within 1.7s+2.739s (+2.33%)
2:04.756Kurt Rezzetano · fastest of 14 · top 5 within 2.0s+6.205s (+5.23%)
152.5Aaron Kaplan+3.2 mph (+2.1%)
-3.076squal -5.198s
97.6%qual 95.9%
47 rule changes (STL: 5, SM: 1, STU: 21, T2: 20)10 weight · 7 cars added · 7 engine · 3 aero · 3 suspension & brakes · 3 tyres & wheels · 1 induction · 12 wording · 1 other · 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. · T2 BMW M235iR/M240iR: 240iR/Evo package penalty removed, EVO package specification clarified. · T2 BMW E92 M3 (08-14) now permits Fall Line Suspension arms for G8X/F8x/E9x M3, E9x M3/E82 1M. · 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. · T2-T4 Touring cars with alternative springs now permitted to use performance top hats with spherical bearings on shocks and struts. · T2 BMW E92 M3 (08-14) notes changed from 77 to 78. · Cadillac CT4-V Blackwing added to T2, 3564 cc, 3800 lbs minimum, 18×10/11 wheels, 295 MT tyres, 380/339 mm brakes. · 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. · T2-T4 touring cars model year 2018+ may use aftermarket ECU with 75 lb weight penalty via spec line adjustment. · T2 BMW M2 CS Cup 2020- now allows exhaust part #18302459928 and hot country package parts. · Cadillac CT4-V Blackwing 2022+ added to T2 with 3564 cc engine, 3800 lbs minimum weight, 18×10 front and 18×11 rear wheels, 295 MT tyres. · STU single throttle body weight reduction removed; minimum weights revised down to 2990 lbs at 3000cc from 3300 lbs. · STL and STU Improved Touring vehicles must now conform to section 9.1.4 Tires & Wheels. · 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. · T2-T4 grill opening removal for cooling permitted without 16 square inch limit; mesh shape must match factory. · T2 Chevrolet Corvette C6 LS2 restrictor increases from 56 mm to 58 mm. · 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. · T2 BMW Z4M 06-08 minimum weight reduced 50 lbs to 3100. · STL/STU intake manifold and cylinder head porting clarified as free; intake and exhaust porting wording removed. · STL Mazda Renesis flat plate restrictor increases from 55mm to 60mm. · STL 79-85 RX7 12A allows emissions removal and jet correction on stock Nikki carb. · 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. · T2 Dodge Viper SRT-10 coupe weight drops to 3550 lbs, throttle restrictor hole shrinks to 41mm. · T2, T3, T4 clarify grill opening removal limited to 16 square inches for radiator cooling; mesh shape must be retained. · T2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted. · T2, T3, T4: clarified that 'permitted' or 'allowed' parts in spec lines are alternatives to category rule allowances, not replacements. · T2 Spec Mustang model designation changed to Ford Spec Mustang. · T2 BMW M2 CS Cup 2020 rear brake rotor minimum thickness reduced from 390 mm to 380 mm. · T4 adds 2014 VW Jetta 1.8T TSI to Spec Lines. · T2 adds 2017+ BMW M2 with 2979cc engine, 10.5x18 wheels, 295 tyres, 3650 lbs minimum weight. · Porsche 911 997.2 GTS (09-12) added to T2 with 60mm flat plate restrictor, 3400 lbs minimum, PDK option at +100 lbs.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 #32733aeroadded · aeroSTU OEM louver vents no longer count against vent allowance or 200 square inch limit.
STU Non 4 valve weight reduction removed #32808weightfaster · weightSTU 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 #32711engineslower · engineSTU 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.
T2 BMW M235iR/M240iR Min Weight Clarification #32430weightfaster · weightT2 BMW M235iR/M240iR: 240iR/Evo package penalty removed, EVO package specification clarified.
T2 Follow up to Letter 30888 #32477suspension & brakesadded · suspension & brakesT2 BMW E92 M3 (08-14) now permits Fall Line Suspension arms for G8X/F8x/E9x M3, E9x M3/E82 1M.
STU Opposed to the Proposed STU Weight Chart #32381tyres & wheelsadded · tyres & 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.
T2 Request Alternate Front & Rear Strut/Shock Top Hats #32452suspension & brakesadded · suspension & brakesT2-T4 Touring cars with alternative springs now permitted to use performance top hats with spherical bearings on shocks and struts.
T2 Request BoP E92 torque #32456wordingwordingT2 BMW E92 M3 (08-14) notes changed from 77 to 78.
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 lbsfaster · weightSTU 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 #31866engineadded · engineSTU 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 #32214weightslower · weightSTU 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 #32393weightfaster · weightSTU single-throttle body cars get lower minimum weights: 2450cc to 2596 lbs, 2500cc to 2635 lbs, 2550cc to 2675 lbs.
T2 Request to Allow the Use of Aftermarket ECU's in Touring #31067engineadded · engineT2-T4 touring cars model year 2018+ may use aftermarket ECU with 75 lb weight penalty via spec line adjustment.
T2 BMW M2 CS Cup 2020- Exhaust #32243engineadded · engineT2 BMW M2 CS Cup 2020- now allows exhaust part #18302459928 and hot country package parts.
T2 RequestT2 classification- 2022 Cadillac CT4-V Blackwing #32263cars addedaddedCadillac CT4-V Blackwing 2022+ added to T2 with 3564 cc engine, 3800 lbs minimum weight, 18×10 front and 18×11 rear wheels, 295 MT tyres.
STL Single TB Weight Modifiers #31449weightfaster · weightSTU single throttle body weight reduction removed; minimum weights revised down to 2990 lbs at 3000cc from 3300 lbs.
STL Improved Touring Tires #32063tyres & wheelstyres & wheelsSTL and STU Improved Touring vehicles must now conform to section 9.1.4 Tires & Wheels.
STU Single TB Weight Modifiers #31449weightfaster · weightSTU 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 #31465weightslower · weightSTU 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.
T2 Reply to letter #31486/29879 T2-T4 Grill openings #31935aerofaster · aeroT2-T4 grill opening removal for cooling permitted without 16 square inch limit; mesh shape must match factory.
T2 C6 Restrictor Help #31995inductionfaster · inductionT2 Chevrolet Corvette C6 LS2 restrictor increases from 56 mm to 58 mm.
STU Request Allowance for Balance Shaft Delete in STU #31434enginefaster · engineSTU 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 #31916aeroadded · aeroSTU hood vents now allow louvers within 200 square inches.
T2 BMW Z4M Adjustment #31885weight -50 lbsfaster · weightT2 BMW Z4M 06-08 minimum weight reduced 50 lbs to 3100.
STL Throttling Device Clarification #31323wordingwordingSTL/STU intake manifold and cylinder head porting clarified as free; intake and exhaust porting wording removed.
STL Mazda Renesis Restriction #31467enginefaster · engineSTL Mazda Renesis flat plate restrictor increases from 55mm to 60mm.
STL Clarification of 79-85 RX7 Spec line #31621wordingwordingSTL 79-85 RX7 12A allows emissions removal and jet correction on stock Nikki carb.
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 #31060enginefaster · engineSTU 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.
T2 Touring 2 BOP adjustments for 2022 #31480weight -50 lbsfaster · weightT2 Dodge Viper SRT-10 coupe weight drops to 3550 lbs, throttle restrictor hole shrinks to 41mm.
T2 Reply to letter 29879 T2-T4 Grill Openings #31486wordingwordingT2, T3, T4 clarify grill opening removal limited to 16 square inches for radiator cooling; mesh shape must be retained.
T2 Request to clarify radiator hoses #31682otheraddedT2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted.
T2 Clarify Permitted/Allowed #31743wordingwordingT2, T3, T4: clarified that 'permitted' or 'allowed' parts in spec lines are alternatives to category rule allowances, not replacements.
T2 SMG #31837wordingwordingT2 Spec Mustang model designation changed to Ford Spec Mustang.
T2 Typo for BMW M2 CS Cup 2020 #31173suspension & brakessuspension & brakesT2 BMW M2 CS Cup 2020 rear brake rotor minimum thickness reduced from 390 mm to 380 mm.
T2 Request to Classify 2014 VW Jetta 1.8t TSI #30436cars addedaddedT4 adds 2014 VW Jetta 1.8T TSI to Spec Lines.
T2 Request new car 2017 BMW M2 #30486cars addedaddedT2 adds 2017+ BMW M2 with 2979cc engine, 10.5x18 wheels, 295 tyres, 3650 lbs minimum weight.
T2 Request to Classify Porsche 997.2 GTS in T2 (body not = to C2S) #30686cars addedaddedPorsche 911 997.2 GTS (09-12) added to T2 with 60mm flat plate restrictor, 3400 lbs minimum, PDK option at +100 lbs.
1:51.665Danny Steyn · fastest of 42 · top 5 within 1.7s-0.982s (-0.87%)
2:02.711Joe Moser · fastest of 37 · top 5 within 3.2s+10.122s (+8.99%)
131.8Max Gee
1:57.695Brian 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
-3.874squal +6.030s
96.8%qual 105.4%
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
-15.270squal -4.587s
87.6%qual 95.9%
1:47.509Kurt Rezzetano · fastest of 26 · top 5 within 1.6s-1.109s (-1.02%)
1:48.474Kurt Rezzetano · fastest of 26 · top 5 within 2.5s-0.295s (-0.27%)
151.5Scotty B. White
-14.237squal -4.156s
88.4%qual 96.3%
58 rule changes (STL: 15, SM: 1, STU: 12, T2: 30)15 cars added · 9 weight · 4 engine · 4 induction · 4 suspension & brakes · 3 aero · 1 tyres & wheels · 13 wording · 5 other · STL Mazda Spec MX-5 removes redundant specification line referencing 2014 regulations. · T2 BMW M2 CS Cup 2020- mandatory power stick part number assigned as #8324089. · T2 Porsche 911/997.1 (06–08) now permits Cargraphics CARP97DFIFKR alternate exhaust manifold. · 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. · T2 BMW M2 CS Cup 2020- weight increases from 3625 to 3600 lbs; Purple power stick mandatory, hot country package allowed. · STL Volkswagen 2.0L TFSI 1984 cc engine permitted without turbocharger, meeting all other STL specs. · T3 Honda Civic Type-R 2020+ allowed brake rotor #45251-TGH-A01 with 25 lb penalty. · T2 Mustang GT 5.0L 15-17 throttle body raised to 58mm, 2018- raised to 55mm. · T2 BMW Z4M 06–08 minimum weight increases 50 lbs, to 3150. · T2 BMW E92M3 weight drops 50 lbs to 3425; intake restrictor shrinks from 80mm to 77mm. · STL Pontiac Solstice/Saturn Sky allowed 4 inch ride height. · STL Mazda B5 DOHC added to class; must meet all STL regulations. · STL Honda B16A (JDM) restrictor reduced from 54mm to 53mm. · STU fender flare rules clarified: maximum 2 inches total, must cover tire contact patch from above, cannot alter body configuration or wheel opening geometry. · T2 Corvettes C5 Z06, C6, and Z06 gain dry sump kit options and air dam trimming allowances. · T2 Chevrolet Camaro 1LE auto trans: gear ratios and final drive 2.77 specified. · T2 BMW M3 01-06 minimum weight reduced from 3100 lbs to 3000 lbs. · T2 Chevrolet Camaro SS/1LE model years expanded to 2010-2015. · SM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture. · ST oil coolers and filters now explicitly listed as addable or substitutable parts in vents and breathers section. · 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. · T2-T4 clutch discs and pressure plates must be at least 95% of factory OEM weight, bolted to unmodified stock flywheel. · Spec Corvette added to T2 with 3375 cc, 295 DOT tires, 53 mm restrictor, 3.75 in minimum ride height, 3200 lbs minimum weight. · T2 BMW E92 M3 front and rear spring rate limit raised from 800 to 1000 #/in. · T2 Toyota Supra 2020+ spring rates limited to 800 lb/in front, 1000 lb/in rear. · STL GM Ecotec LNF now permits any Ecotec engine family with 55mm flat plate restrictor. · ST 90-05 Mazda Miata allowed alternate front wheel hub Mazda Motorsports Development Part #0000-04-5HUB-S1. · ST 90-05 Mazda Miata allowed alternate front wheel hub Mazda Motorsports Development Part #0000-04-5HUB-S1. · T2 BMW M2 CS Cup 2020- permitted to remove door glass and mechanism. · ST cars may now relocate ABS actuation hardware and wiring anywhere in the engine compartment. · STL rear wing trailing edge may be mounted no further rearward than the center of the rearmost part approved bodywork. · STL alternate transmissions now allow OEM gear sets and input shaft modifications for fitment. · 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. · T2 BMW M235iR gains M240iR/Evo package option with 50 lb penalty and DOT tyre requirement. · Toyota Supra 2020- added to T2 with 2998 cc engine, 3450 lbs minimum weight, 19×10 wheels, 295 tyres. · T2 Honda Civic Type-R gains allowance for PRL cold air intake #PRL PRL-HCR-INT-HVI. · T2 Porsche Carrera S 997.2 (06-08) weight reduced 50 lbs to 3225. · T2 Ford Mustang GT 5.0L 15-17 gear ratios changed to 3.66, 2.43, 1.69, 1.32, 1.00, 0.65 or 4.17, 2.34, 1.52, 1.14, 0.87, 0.69. · T2 BMW Z4M 06-08 maximum wheel size increases from 18×9 to 18×10 inches. · T2 BMW M2 CS Cup 2020- and M235iR (-2016) clarify homologation and touring rule allowances in Notes. · STL RWD strut-front cars lose 2.5% weight penalty, others lose 3% penalty for FWD parity. · STL Honda F20C drops 2% weight penalty, minimum weight reduced. · STL Honda B16/B17/B18C1 restrictor reduced to 53mm, B18C variants and Mazda MZR to 52mm. · STU Mazda 13B Spec and Bridge Port removed; Street Port added at 2400 lbs minimum weight. · T2 BMW M2 CS Cup 2020+ classified at 2979 cc, 3625 lbs, 295 tires, 10.5×18 wheels, 380/390 mm brakes. · T2 and T3 Nissan 350Z and 370Z permit 44011-RC350 rear caliper kit and SZ350 rotors; T2 350Z also permits Stillen 400338. · T4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.55 final drive, plus 25 lb penalty. · T3 Scion FR-S/Toyota 86 and Subaru BRZ capped to 2021 model year; T4 models capped to 2021. · ST aero devices and reference areas must include end plates, exclude fasteners under 1/2" protrusion. · ST aero devices and reference areas must include end plates, exclude fasteners under 1/2" protrusion. · T2 BMW E92 M3 (08-14) minimum weight reduced 50 lbs to 3475; brake, suspension, restrictor and transmission specs clarified with duplicate AP Racing line removed. · T2 Corvette C5 Z06 restrictor sizes increase to 53mm and 58mm; C6 LS2 to 56mm, LS3 to 50mm; Camaro SS/1LE weight drops 75 lbs to 3625; Camaro 1LE restrictor to 56mm; Mustang GT 11-14 to 58mm; 15-17 to 55mm; 2018- to 53mm; Viper restrictor … · T3 Alfa Romeo 4C Launch Edition variant now allowed.showhide
STL Request to clean up Spec MX-5 Redundancy #31069wordingwordingSTL Mazda Spec MX-5 removes redundant specification line referencing 2014 regulations.
T2 BMW M2 CS Power Stick Part Number #31087wordingwordingT2 BMW M2 CS Cup 2020- mandatory power stick part number assigned as #8324089.
T2 997.1 EO #30933cars addedaddedT2 Porsche 911/997.1 (06–08) now permits Cargraphics CARP97DFIFKR alternate exhaust manifold.
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 lbsfaster · weightSTU Mazda 12A Bridgeport weight reduced from 2550 lbs to 2350 lbs.
T2 Request #30406wordingunclearT2 BMW M2 CS Cup 2020- weight increases from 3625 to 3600 lbs; Purple power stick mandatory, hot country package allowed.
STL VW Engine Request #30625engineadded · engineSTL Volkswagen 2.0L TFSI 1984 cc engine permitted without turbocharger, meeting all other STL specs.
T2 Civic Type R Brake Rotors #29817weightslower · weightT3 Honda Civic Type-R 2020+ allowed brake rotor #45251-TGH-A01 with 25 lb penalty.
T2 Mustang S550 Parity in T2 #29925inductionfaster · inductionT2 Mustang GT 5.0L 15-17 throttle body raised to 58mm, 2018- raised to 55mm.
T2 Request BOP on BMW Z4 T2 car #30597weight +50 lbsslower · weightT2 BMW Z4M 06–08 minimum weight increases 50 lbs, to 3150.
T2 E92 #30639weight -50 lbsfaster · weightT2 BMW E92M3 weight drops 50 lbs to 3425; intake restrictor shrinks from 80mm to 77mm.
STL Request Mazda B5 DOHC #30420cars addedaddedSTL Mazda B5 DOHC added to class; must meet all STL regulations.
STL Honda B16A (JDM) Restrictor change #30531engineslower · engineSTL Honda B16A (JDM) restrictor reduced from 54mm to 53mm.
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.
T2 C5/6 Corvette in T1, T1-LP and T2 Dry Sump Standardization #29046otheraddedT2 Corvettes C5 Z06, C6, and Z06 gain dry sump kit options and air dam trimming allowances.
T2 Request for Chevrolet Camaro 1LE (2016-) Auto Trans #29067cars addedaddedT2 Chevrolet Camaro 1LE auto trans: gear ratios and final drive 2.77 specified.
T2 Request E46 M3 Minimum Competition Weight #29429weight -100 lbsfaster · weightT2 BMW M3 01-06 minimum weight reduced from 3100 lbs to 3000 lbs.
T2 Request to add 2015 to Chevrolet Camaro SS/1LE 2010-2014 #29736cars addedaddedT2 Chevrolet Camaro SS/1LE model years expanded to 2010-2015.
SM Updates - Obsolete Parts & BOP Parts #30438wordingaddedSM adds procedure for CRB-approved obsolete parts and BOP testing in sanctioned events with point forfeiture.
STL 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.
STU Provision for Interchangeable Engine Components Already Allowed #30342engineadded · engineSTU 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.
T2 Request consistency review in GCR #30263wordingwordingT2-T4 clutch discs and pressure plates must be at least 95% of factory OEM weight, bolted to unmodified stock flywheel.
T2 Class Spec Corvette in T2? #30297cars addedaddedSpec Corvette added to T2 with 3375 cc, 295 DOT tires, 53 mm restrictor, 3.75 in minimum ride height, 3200 lbs minimum weight.
T2 E92 BMW Spring Rate Request #30391suspension & brakesfaster · suspension & brakesT2 BMW E92 M3 front and rear spring rate limit raised from 800 to 1000 #/in.
T2 Please correct recent T2 Spec Line #30401suspension & brakessuspension & brakesT2 Toyota Supra 2020+ spring rates limited to 800 lb/in front, 1000 lb/in rear.
STL GM Ecotec engines in STL #30247engineadded · engineSTL GM Ecotec LNF now permits any Ecotec engine family with 55mm flat plate restrictor.
STL 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 Super Touring Alternate Miata Hubs #30345cars addedaddedST 90-05 Mazda Miata allowed alternate front wheel hub Mazda Motorsports Development Part #0000-04-5HUB-S1.
T2 Request BMW M2CS door glass removal #30254cars addedaddedT2 BMW M2 CS Cup 2020- permitted to remove door glass and mechanism.
STL Brake Component Relocation #29990suspension & brakessuspension & brakesST cars may now relocate ABS actuation hardware and wiring anywhere in the engine compartment.
STL Super Touring Wing Clarification #30111aeroaeroSTL rear wing trailing edge may be mounted no further rearward than the center of the rearmost part approved bodywork.
STL Transmission Options #30118otheraddedSTL alternate transmissions now allow OEM gear sets and input shaft modifications for fitment.
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.
T2 Request Addition of BMW M240iR #29503cars addedaddedT2 BMW M235iR gains M240iR/Evo package option with 50 lb penalty and DOT tyre requirement.
T2 2021 Toyota Supra #29567cars addedaddedToyota Supra 2020- added to T2 with 2998 cc engine, 3450 lbs minimum weight, 19×10 wheels, 295 tyres.
T2 Request Cold Air Intake for Honda Civic Type R #29942inductionadded · inductionT2 Honda Civic Type-R gains allowance for PRL cold air intake #PRL PRL-HCR-INT-HVI.
T2 Adjust T2 spec line that was missed in T2 BOP #30055weight -50 lbsfaster · weightT2 Porsche Carrera S 997.2 (06-08) weight reduced 50 lbs to 3225.
T2 Fix T2 Mustang spec line #30106otherunclearT2 Ford Mustang GT 5.0L 15-17 gear ratios changed to 3.66, 2.43, 1.69, 1.32, 1.00, 0.65 or 4.17, 2.34, 1.52, 1.14, 0.87, 0.69.
T2 Z4 Wheel Size #30113tyres & wheelsfaster · tyres & wheelsT2 BMW Z4M 06-08 maximum wheel size increases from 18×9 to 18×10 inches.
T2 Clarify T2 Spec lines #30194wordingwordingT2 BMW M2 CS Cup 2020- and M235iR (-2016) clarify homologation and touring rule allowances in Notes.
STL Request for FWD and RWD Parity #29728weightfaster · weightSTL RWD strut-front cars lose 2.5% weight penalty, others lose 3% penalty for FWD parity.
STL Request for FWD and RWD Parity #30023inductionslower · inductionSTL Honda B16/B17/B18C1 restrictor reduced to 53mm, B18C variants and Mazda MZR to 52mm.
STU 13B Rules Adjustment #29333cars addedremoved · cars addedSTU Mazda 13B Spec and Bridge Port removed; Street Port added at 2400 lbs minimum weight.
T2 Request to Classify BMW M2 CS #29523cars addedaddedT2 BMW M2 CS Cup 2020+ classified at 2979 cc, 3625 lbs, 295 tires, 10.5×18 wheels, 380/390 mm brakes.
T2 350Z Rear Caliper Replacement #29710cars addedaddedT2 and T3 Nissan 350Z and 370Z permit 44011-RC350 rear caliper kit and SZ350 rotors; T2 350Z also permits Stillen 400338.
T2 Request Mustang 8.8†rear axle replacement #29860cars addedaddedT4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.55 final drive, plus 25 lb penalty.
T2 Cap year range on all 86s #29908wordingwordingT3 Scion FR-S/Toyota 86 and Subaru BRZ capped to 2021 model year; T4 models capped to 2021.
STL Request clarification on wing measurement #29640aeroaeroST aero devices and reference areas must include end plates, exclude fasteners under 1/2" protrusion.
STU Request clarification on wing measurement #29640aeroaeroST aero devices and reference areas must include end plates, exclude fasteners under 1/2" protrusion.
T2 Request to Reevaluate T2 Spec Line for E92 M3 #28266weight -50 lbsfaster · weightT2 BMW E92 M3 (08-14) minimum weight reduced 50 lbs to 3475; brake, suspension, restrictor and transmission specs clarified with duplicate AP Racing line removed.
T2 Request for Parity Among Vehicles Including S550 Mustang #29486induction -75 lbsfaster · inductionT2 Corvette C5 Z06 restrictor sizes increase to 53mm and 58mm; C6 LS2 to 56mm, LS3 to 50mm; Camaro SS/1LE weight drops 75 lbs to 3625; Camaro 1LE restrictor to 56mm; Mustang GT 11-14 to 58mm; 15-17 to 55mm; 2018- to 53mm; Viper restrictor …
2:31.420Danny Steyn · fastest of 33 · top 5 within 3.1s
2:32.115Joe Moser · fastest of 30 · top 5 within 1.5s
132.9Darin Treakle
2:42.209Kyle Greenhill · fastest of 77 · top 5 within 0.5s
2:43.748Preston Pardus · fastest of 75 · top 5 within 1.0s
121.3Kyle Greenhill
+11.633squal +10.789s
107.6%qual 107.1%
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
-3.705squal -3.537s
97.6%qual 97.7%
2:24.195Alan Kossof · fastest of 15 · top 5 within 2.5s
2:26.803Kurt Rezzetano · fastest of 14 · top 5 within 2.2s
147.3Mark Boden
-5.312squal -7.225s
96.5%qual 95.2%
60 rule changes (STL: 11, SM: 2, STU: 17, T2: 30)13 cars added · 9 weight · 8 engine · 7 suspension & brakes · 1 aero · 1 tyres & wheels · 15 wording · 6 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. · T2 Ford Mustang GT 5.0L and Ecoboost 2.3 sway bar part numbers added to notes: M-FR3A-M8 kit, bars M5490-E or M5490-G. · STU fender flare rule reworded: now per-corner up to 2" total, 1% weight penalty applies to entire modification. · T2 stock replacement brake rotors now allow 2-piece ferrous disks with aluminum hats, within 5% of OE diameter. · T2 Porsche Cayman S, Spyder 10-12 gains cooler ducting, springs to 800#/in front and 1000#/in rear, rotor ducting, and specific Stop Tech calipers with 343 mm front rotor. · 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. · 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. · T2 Ford Mustang EcoBoost and GT 5.0L gain three optional gear ratio sets for competition. · GT3 and STU add Borg-Warner EFR6258 turbocharger to approved turbo lists. · 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. · Request to add vehicle to T2, T3, T4 roster; refer to letter #27663 in June 2020 Fastrack for decision. · T2 Porsche Cayman S, Spyder 10-12 gains brake, suspension, steering, and aero upgrades including StopTech calipers, 800#/in front and 1000#/in rear springs, and free sway bars. · STL adds Mazda MX-5 Global Cup 16-18 at 2450 lbs minimum and 2019 at 2550 lbs minimum. · STL Mazda MX-5 Club 06-15 allowed header part number 0000-06-5407-NC. · STL Acura/Honda B18 and B18C engines: restrictor sizes swapped, B18C1 removed from allowed variants. · STU Mazda 13B Bridge Port and Street Port added with 2550 lbs and 2250 lbs minimum weight respectively. · 2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine, 17-inch wheels, 245 tyres, EIBACH PN# 2563.140 springs allowed. · T1 and T2 Corvettes now allow coilover suspension with 800 lb max coil springs; T1 Z06 conversion no longer T1-only. · STL Honda B18 loses 53mm restrictor requirement; B18C1 added with 54mm restrictor, B18C1 removed from other variants. · T2 BMW E92 M3 08-14 adds AP Racing brake kit front 13.01.10038, rear 13.01.10053 to allowed list. · T2 Corvette C5 Z06 weight drops 50 lbs to 3175 with 45mm restrictor, 50 lbs to 3350 with 55mm. · T3 BMW Z3 M & Coupe 98-99 minimum weight reduced to 3150 lbs. · STU GM Ecotech LNF now permitted without turbo, with LE5 head and intake manifold, meeting STL specs. · STL Mazda MZR restrictor reduced from 54 mm to 53 mm. · STL Mazda MZR restrictor reduces from 55 mm to 53 mm. · 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. · T2 Porsche 911 997 and 997.2 Carrera S require OEM rear deck lid; GT3 Cup front fascia allowed with 75 lb penalty, GT3 Cup splitter banned. · T2 Ford Mustang GT 5.0L 15-17 transmission gear ratios corrected to 3.66, 2.43, 1.69, 1.32, 1.00, 0.65 or 4.69, 2.98, 2.14, 1.76, 1.52, 1.27, 1.00, 0.85, 0.68, 0.63. · STL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL to notes. · 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. · T2 Porsche 911/997 (06-08), 997.2 (09-12), Carrera S (06-08): spoiler, bumper, airdams, rear wing height rules removed. · Pontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18x9.5, Sky weight drops to 3200 lbs. · T2 ferrous metal two-piece brake rotors allowed, must be within 5% of OE diameter. · Mazda RX-8 Base/R3/Sport/GT (04-12) classified in T3 effective 2020-02-01. · T2 Nissan 370Z gains StopTech brake kit allowance with 50 lb penalty. · T2 Ford Mustang Ecoboost 2.3 loses 100 lbs to 3400, wheels widen to 19 x 11, intercooler and suspension parts allowed. · T2 Mustang GT5.0L (15-17) wheels change to 19 x 11; Brembo BBK 380mm rotors now permitted at no weight penalty instead of +50 lbs. · T2 must have fire system installed; T3 and T4 may have one per GCR 9.3. · T3 Ford Mustang EcoBoost gains three transmission gear ratio options. · T2 Chevrolet Camaro SS 10-14 adds 1LE-SS Track Pack with dry sump, suspension and brake options permitted. · T2 Camaro SS/1LE (10-14) permits 1LE-SS Track Pack, specific suspension, brake, dry sump, and driveshaft parts. · T2 Chevrolet Camaro 1LE 2016- minimum weight cut to 3550 lbs from 3600 lbs. · T2 Honda Civic Type-R 2017- minimum weight drops 50 lbs to 3000; tire TIR spec increases to 51mm. · T3 and T4 Mazda RX-8 Base/R3 (04-12) reclassified to include Sport and GT variants. · Toyota 86 GT variant (2017–) added to T3 and T4 spec lines. · 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.
T2 Request 2018+ mustang swaybar update #28659suspension & brakesadded · suspension & brakesT2 Ford Mustang GT 5.0L and Ecoboost 2.3 sway bar part numbers added to notes: M-FR3A-M8 kit, bars M5490-E or M5490-G.
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.
T2 Request to Clarify New 2-piece Brake Rotor Rule #29106otherotherT2 stock replacement brake rotors now allow 2-piece ferrous disks with aluminum hats, within 5% of OE diameter.
T2 please consider BoP for the following cars in T2 #29266weight -50 lbs
T2 Request clarification on most recent approval by the Board #29284otheraddedT2 Porsche Cayman S, Spyder 10-12 gains cooler ducting, springs to 800#/in front and 1000#/in rear, rotor ducting, and specific Stop Tech calipers with 343 mm front rotor.
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.
STL Minimum Weight Determination #27695wordingwordingSTL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis percentage additions, subtractions, and fixed pounds.
STL ST Gurney flap Wicker clarification #29012wordingwordingSTL STU rear wing Gurney flap terminology clarified from wicker to Gurney flap in mounting and chord rules.
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.
T2 Request to correct GCR for 2018+ FORD Mustang GT & Ecoboost #28803otheraddedT2 Ford Mustang EcoBoost and GT 5.0L gain three optional gear ratio sets for competition.
STL Request for Addition to GT3 Approved Turbo List #27576cars addedaddedGT3 and STU add Borg-Warner EFR6258 turbocharger to approved turbo lists.
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.
T2 Request to Add a Vehicle to the Roster (contd.) #27698wordingunclearRequest to add vehicle to T2, T3, T4 roster; refer to letter #27663 in June 2020 Fastrack for decision.
T2 Request brake upgrade and electric power steering pump #28946suspension & brakesfaster · suspension & brakesT2 Porsche Cayman S, Spyder 10-12 gains brake, suspension, steering, and aero upgrades including StopTech calipers, 800#/in front and 1000#/in rear springs, and free sway bars.
STL Request to add 2016-2019 GMX-5 Spec line #28604cars addedaddedSTL adds Mazda MX-5 Global Cup 16-18 at 2450 lbs minimum and 2019 at 2550 lbs minimum.
STL Request to update PN for MX-5 #28622cars addedaddedSTL Mazda MX-5 Club 06-15 allowed header part number 0000-06-5407-NC.
STL Correction - Clarification Honda/Acura B18B engine Letter # 26209 #28873wordingwordingSTL Acura/Honda B18 and B18C engines: restrictor sizes swapped, B18C1 removed from allowed variants.
STU Rotary Help #27833cars addedaddedSTU Mazda 13B Bridge Port and Street Port added with 2550 lbs and 2250 lbs minimum weight respectively.
T2 Request to Classify 2004 Mercedes Benz 320 CLK #27663cars addedadded2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine, 17-inch wheels, 245 tyres, EIBACH PN# 2563.140 springs allowed.
T2 Consider coil spring conversion Corvette in T2 #28824suspension & brakesadded · suspension & brakesT1 and T2 Corvettes now allow coilover suspension with 800 lb max coil springs; T1 Z06 conversion no longer T1-only.
STL STL Honda B18 restrictor changes #28794enginefaster · engineSTL Honda B18 loses 53mm restrictor requirement; B18C1 added with 54mm restrictor, B18C1 removed from other variants.
T2 Please Add the Following BBK to Allowed List for E92 M3 #28421suspension & brakesadded · suspension & brakesT2 BMW E92 M3 08-14 adds AP Racing brake kit front 13.01.10038, rear 13.01.10053 to allowed list.
T2 C5 Weight Adjustment #28433weight -50 lbsfaster · weightT2 Corvette C5 Z06 weight drops 50 lbs to 3175 with 45mm restrictor, 50 lbs to 3350 with 55mm.
T2 Z3M Roadster Weight #28437weightfaster · weightT3 BMW Z3 M & Coupe 98-99 minimum weight reduced to 3150 lbs.
STL Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0 #27884engineadded · engineSTU GM Ecotech LNF now permitted without turbo, with LE5 head and intake manifold, meeting STL specs.
STL Acura/Honda B18C engine chart. Reduce the current 54 mm flat plat #28663engineslower · engineSTL Mazda MZR restrictor reduced from 54 mm to 53 mm.
STL Mazda MZR engine chart. Reduce the current 55 mm flat plate to 53 #28664engineslower · engineSTL Mazda MZR restrictor reduces from 55 mm to 53 mm.
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 lbsslower · weightSTU 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 #27732engineslower · engineSTU 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 #27884engineadded · engineSTU GM Ecotech LNF now permitted without turbo, with LE5 head and intake manifold, meeting STL specs.
STU Alternate Engine for Porsche 944 #28259engineadded · engineSTU Porsche 944 now permits VW/Audi 1.8L and 2.0L turbo engines as alternates to original.
T2 Limit Changes to the 997.2 Porsche #28242aeroslower · aeroT2 Porsche 911 997 and 997.2 Carrera S require OEM rear deck lid; GT3 Cup front fascia allowed with 75 lb penalty, GT3 Cup splitter banned.
STL Request to add wheel part numbers #28342cars addedaddedSTL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL to notes.
STU Please Modify the STU Wheel Size Rule for Clarity #27694weightfaster · weightSTU 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.
T2 Request to Readjust the T2 Porsches #27746wordingwordingT2 Porsche 911/997 (06-08), 997.2 (09-12), Carrera S (06-08): spoiler, bumper, airdams, rear wing height rules removed.
T2 Please Switch the Solstice GXP as Specified in T2, to T3 #27413cars added -50 lbsfaster · cars addedPontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18x9.5, Sky weight drops to 3200 lbs.
T2 Request for Two Piece Stop Tech Brake Rotors #27582suspension & brakessuspension & brakesT2 ferrous metal two-piece brake rotors allowed, must be within 5% of OE diameter.
T2 Request to Classify all Mazda RX8 Models in T3/T4 #27606cars addedaddedMazda RX-8 Base/R3/Sport/GT (04-12) classified in T3 effective 2020-02-01.
T2 Request for Alternative Brake Kit on Nissan 370Z #27912suspension & brakesslower · suspension & brakesT2 Nissan 370Z gains StopTech brake kit allowance with 50 lb penalty.
T2 2015- Current Ecoboost Mustang #27971weight -100 lbsfaster · weightT2 Ford Mustang Ecoboost 2.3 loses 100 lbs to 3400, wheels widen to 19 x 11, intercooler and suspension parts allowed.
T2 T2 Mustang #28022tyres & wheelsfaster · tyres & wheelsT2 Mustang GT5.0L (15-17) wheels change to 19 x 11; Brembo BBK 380mm rotors now permitted at no weight penalty instead of +50 lbs.
T2 Clarification of On-Board Fire System for T2 #27183wordingwordingT2 must have fire system installed; T3 and T4 may have one per GCR 9.3.
T2 Mustang Ecoboost and GT Transmission #27439cars addedaddedT3 Ford Mustang EcoBoost gains three transmission gear ratio options.
T2 Request for Dailey Engineering Dry Sump on 2010 Camaro SS #27514cars addedaddedT2 Chevrolet Camaro SS 10-14 adds 1LE-SS Track Pack with dry sump, suspension and brake options permitted.
T2 Request for Half Shafts - 2014 Camaro SS 1LE #27584otheraddedT2 Camaro SS/1LE (10-14) permits 1LE-SS Track Pack, specific suspension, brake, dry sump, and driveshaft parts.
T2 Request for Parity Among Vehicles #27665weight -50 lbs
T2 Request for 2016-2020 Camaro SS Help #27776weight -50 lbsfaster · weightT2 Chevrolet Camaro 1LE 2016- minimum weight cut to 3550 lbs from 3600 lbs.
T2 Request for Competitive Adjustments to Honda Civic Type R #27839weight -50 lbsfaster · weightT2 Honda Civic Type-R 2017- minimum weight drops 50 lbs to 3000; tire TIR spec increases to 51mm.
T2 T4 RX8 Classification Error #27902cars addedaddedT3 and T4 Mazda RX-8 Base/R3 (04-12) reclassified to include Sport and GT variants.
T2 Request to add Toyota 86 GT to Spec Line #27910cars addedaddedToyota 86 GT variant (2017–) added to T3 and T4 spec lines.
STU Request for an electronic throttle body #27342engineadded · engineSTU allows OEM electronic throttle bodies, manual conversion, cam changes, and manual-to-electronic conversion with same inner diameter.
2:07.203Danny Steyn · fastest of 36 · top 5 within 1.8s
2:07.273Cliff Ira · fastest of 35 · top 5 within 1.4s
134.8Cliff Ira
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
+9.186squal +7.349s
107.2%qual 105.8%
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
-6.790squal -7.255s
94.7%qual 94.3%
1:57.537Cooper I MacNeil · fastest of 19 · top 5 within 3.4s
1:58.551Cooper I MacNeil · fastest of 18 · top 5 within 2.4s
149.4James Leithauser
-8.722squal -9.666s
93.1%qual 92.4%
60 rule changes (STL: 11, SM: 4, STU: 22, T2: 23)14 cars added · 8 engine · 7 suspension & brakes · 4 aero · 4 induction · 3 weight · 1 tyres & wheels · 14 wording · 5 other · STL adds Mazda Spec MX-5 Challenge, 2000cc displacement, 2500 lb minimum weight, with mandatory Roush, Penske, Eibach, and other specified components. · STU wing assembly wording corrected: no part may be higher than roof height. · T2, T3, T4 spare tire and cover removal wording clarified; removable covers now explicitly allowable to remove. · STU allows alternate intake manifolds on case-by-case basis; stock throttle device and manifold otherwise required. · 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. · T2 Cadillac CTS-V classification expanded from 2006-07 model years to include 2004-05 models. · T2 Cadillac CTS-V 06-07 gains allowance for Hotchkiss sway bars up to 36mm front, 25mm rear. · T2 Cadillac CTS-V 06-07 requires 57mm flat plate restrictor. · T2 Ford Mustang GT 5.0L tire width reduced from 315 to 295. · STL Acura/Honda B18 except C engine restrictor increased from 53mm to 54mm flat plate. · 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. · T2 Audi TT RS 2018+ gains front sway bar to 30mm, rear to 28mm, springs to 1200 lb/in, aftermarket intercooler. · T2 Honda Civic Type-R 2017+ minimum weight rises 150 lbs to 3050, TIR turbo restrictor enlarges 38mm to 50mm. · STL and STU ride height measurement clarified: lowest rocker panel point without driver, excluding pinch weld. · 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. · T2 Mustang GT rear anti-roll bar may now be removed or disconnected. · SM fuel pump and filter now permitted as Mazda or OEM equivalent part. · STL adds VW 1.8L R4 20VT 1781 cc, 1781 minimum weight, naturally aspirated only. · STL Mazda Renesis minimum weight reduced to 2700 lbs. · STL Mazda MX-5 Cup brake pad compound now open. · STL adds Acura/Honda B18C1 GSR with 1797cc displacement, 54mm flat plate restrictor required, porting outside 1" allowance prohibited. · STL Mazda 12 and 13B now permit port matching; porting ban removed. · 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. · T1-LP Ford Mustang GT 5.0L 2018- classified at 3400 lbs with 65mm restrictor, T2 and T3 Mustangs limited to 2015-2017. · T2 Audi TT RS (2018-) newly classified: 2480cc, 3400 lbs minimum, 19-inch wheels, 275 tires, 371/310mm brakes, 40mm TIR required. · T2 2017+ Civic Type R sway bar rules relaxed: any front/rear up to 30mm allowed, specific HPD parts no longer required. · T4 and T3 Mazda MX-5 hardtop rules clarified: any OEM or aftermarket top permitted if retaining OEM silhouette; specific part numbers listed. · T2, T3, T4 now allow any thermostat serving original equipment intent only. · T2 Ford Mustang Boss 302 (12-13) minimum weight drops to 3500 lbs. · T2 Corvette C6 Coupe/Grand Sport 05-13 front camber maximum 3.0 degrees removed. · T2 Pontiac Firebird and Chevrolet Camaro SS 98-02 permit spring relocation to shock. · T3 and T4 Mazda MX-5 Miata eligibility capped at 2016–2018 model years. · Ford Mustang GT 5.0L 2018+ classified in T2 at 3600 lbs minimum with 50mm restrictor, 19×11 wheels, 315 tyres, specific Ford Performance parts permitted. · 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. · STL B17 now requires 54mm flat plate restrictor; B18C Type R variants move to 54mm restrictor, weight chart baseline. · STL Mazda Miata removes maximum displacement limit; minimum weight corrected to unspecified figure. · STU adds Honda K20C1 Turbo I4, 1996 cc, 3025 lbs minimum weight, 36mm TIR required. · T4 Celica GT wheelbase 2600 and 15x7 wheels added; Forte years narrowed; Fiesta ST starts 2014; Fiat 124 years 16-18 added; battery rule clarified. · T2 Porsche Cayman S/GTS years extended from 13-14 to 13-15, adding 2015 GTS model. · T2 Honda Civic Type-R 2017- allowed Cuztom Tuning FG-CIV16-V3-TR-BK alternate grill. · T1–T4 spec car classifications clarified with permitted parts, rule conformance versions, and exclusions of other touring modifications. · T2–T4 subframe bushings now permitted to be replaced with non-spherical bushings of any material.showhide
STL Request to Classify Spec MX-5 Challenge in STL #27399cars addedaddedSTL adds Mazda Spec MX-5 Challenge, 2000cc displacement, 2500 lb minimum weight, with mandatory Roush, Penske, Eibach, and other specified components.
STU Request to correct E&O advanced aerodynamics #27290wordingwordingSTU wing assembly wording corrected: no part may be higher than roof height.
T2 Request spare tire/wheel clarification #27012wordingfasterT2, T3, T4 spare tire and cover removal wording clarified; removable covers now explicitly allowable to remove.
STL 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.
STU Remove -2mm penalty from SR20DET Nissan #26982enginefaster · engineSTU 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.
T2 Request to change Cadillac CTS-V years from 06-07 to 04-07 #26842cars addedaddedT2 Cadillac CTS-V classification expanded from 2006-07 model years to include 2004-05 models.
T2 Request to allow Hotchkiss front / rear sway bars on T2 CTS-V #26845suspension & brakesadded · suspension & brakesT2 Cadillac CTS-V 06-07 gains allowance for Hotchkiss sway bars up to 36mm front, 25mm rear.
T2 Correct T2 Mustang tire size #27024tyres & wheelsslower · tyres & wheelsT2 Ford Mustang GT 5.0L tire width reduced from 315 to 295.
STL Request Restrictor Plate correction #26779enginefaster · engineSTL Acura/Honda B18 except C engine restrictor increased from 53mm to 54mm flat plate.
STU Request to clarify afterrmarket side skirts exhaust exit #26814aeroadded · aeroSTU 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.
T2 2018+ Audi TT RS Suspension Allowances #26631suspension & brakesadded · suspension & brakesT2 Audi TT RS 2018+ gains front sway bar to 30mm, rear to 28mm, springs to 1200 lb/in, aftermarket intercooler.
T2 Request BOP adjustment for 2018 Honda Civic Type R-TIR removal #26882weight +150 lbsfaster · weightT2 Honda Civic Type-R 2017+ minimum weight rises 150 lbs to 3050, TIR turbo restrictor enlarges 38mm to 50mm.
STL Request Ride Height Clarification #26597wordingwordingSTL and STU ride height measurement clarified: lowest rocker panel point without driver, excluding pinch weld.
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 #25790engineadded · engineSTU 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. #26352inductionadded · inductionSTU 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 #26530engineadded · engineSTU 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 #26606inductionslower · inductionSTU 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.
T2 Request for Removal of Rear Anti-roll Bar in T2 Mustang GT #26533suspension & brakesfaster · suspension & brakesT2 Mustang GT rear anti-roll bar may now be removed or disconnected.
SM Request to allow aftermarket fuel filters. #26370otheraddedSM fuel pump and filter now permitted as Mazda or OEM equivalent part.
STL Request to reduce weight of RX8 with Renesis rotary #25781weight -100 lbsfaster · weightSTL Mazda Renesis minimum weight reduced to 2700 lbs.
STL Request for Open Brake Pads On Mazda MX-5 Cup NC #25821otheraddedSTL Mazda MX-5 Cup brake pad compound now open.
STL Request to clarify B18C1 GSR Honda B motor table #26209cars addedaddedSTL adds Acura/Honda B18C1 GSR with 1797cc displacement, 54mm flat plate restrictor required, porting outside 1" allowance prohibited.
STL Port Matching #26415enginefaster · engineSTL Mazda 12 and 13B now permit port matching; porting ban removed.
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 #25564engineadded · engineSTU 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 #26398inductionfaster · inductionSTU AWD/RWD cars no longer must reduce restrictor 1 mm from table.
STU Advanced Aero E&O #26413aeroadded · aeroSTU rear wing maximum 12" cord, 72 sq in end plates each, roof height max, body width limit.
T2 Request Mustang GT Limited Prep 2018 Classification #24431cars addedaddedT1-LP Ford Mustang GT 5.0L 2018- classified at 3400 lbs with 65mm restrictor, T2 and T3 Mustangs limited to 2015-2017.
T2 Request to Classify 2018 Audi TT RS #25961cars addedaddedT2 Audi TT RS (2018-) newly classified: 2480cc, 3400 lbs minimum, 19-inch wheels, 275 tires, 371/310mm brakes, 40mm TIR required.
T2 Request for Adjustments on 2017+ Civic Type R #25969suspension & brakessuspension & brakesT2 2017+ Civic Type R sway bar rules relaxed: any front/rear up to 30mm allowed, specific HPD parts no longer required.
T2 Correct Mazda MX-5 Hard Top Notes #26137wordingwordingT4 and T3 Mazda MX-5 hardtop rules clarified: any OEM or aftermarket top permitted if retaining OEM silhouette; specific part numbers listed.
T2 Consider opening class rules to allow any thermostat #26187engineadded · engineT2, T3, T4 now allow any thermostat serving original equipment intent only.
T2 Ford Mustang Boss 302 (12-13) - correct weight #26287weight -50 lbsfaster · weightT2 Ford Mustang Boss 302 (12-13) minimum weight drops to 3500 lbs.
T2 Request camber correction 005-2013 corvette C6 #26288suspension & brakesremoved · suspension & brakesT2 Corvette C6 Coupe/Grand Sport 05-13 front camber maximum 3.0 degrees removed.
T2 Request 98-02 Firebird 98-02 Camaro reloacte rear spring #26291suspension & brakesadded · suspension & brakesT2 Pontiac Firebird and Chevrolet Camaro SS 98-02 permit spring relocation to shock.
T2 Cap 2016 Mazda Miata year at 2018 #26388cars addedremoved · cars addedT3 and T4 Mazda MX-5 Miata eligibility capped at 2016–2018 model years.
T2 Class Ford Mustang GT 2018+ (reference letter 24431) #26400cars addedaddedFord Mustang GT 5.0L 2018+ classified in T2 at 3600 lbs minimum with 50mm restrictor, 19×11 wheels, 315 tyres, specific Ford Performance parts permitted.
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.
STL Request to equalize FPR Reduction on all B-Series Vtec Engines #24746enginefaster · engineSTL B17 now requires 54mm flat plate restrictor; B18C Type R variants move to 54mm restrictor, weight chart baseline.
STL Request E&O for Mazda Miata Spec Line #25955otherunclearSTL Mazda Miata removes maximum displacement limit; minimum weight corrected to unspecified figure.
STU Request to Equalize Direct Injected Turbo Cars #24890cars addedaddedSTU adds Honda K20C1 Turbo I4, 1996 cc, 3025 lbs minimum weight, 36mm TIR required.
T2 Errors, Omissions, and Updates (Various) #22414wordingwordingT4 Celica GT wheelbase 2600 and 15x7 wheels added; Forte years narrowed; Fiesta ST starts 2014; Fiat 124 years 16-18 added; battery rule clarified.
T2 Request to classify 2015 Cayman GTS 3.4L in T2 #25335cars addedaddedT2 Porsche Cayman S/GTS years extended from 13-14 to 13-15, adding 2015 GTS model.
T2 Request for 2017-2018 Honda Civic Type R - 4 BOP Grill #25513aeroadded · aeroT2 Honda Civic Type-R 2017- allowed Cuztom Tuning FG-CIV16-V3-TR-BK alternate grill.
T2 Add Clarification to Spec Car Classifications Vehicle Spec #25774wordingwordingT1–T4 spec car classifications clarified with permitted parts, rule conformance versions, and exclusions of other touring modifications.
T2 Clarify Subframe Bushings Permitted for T2-T4 #25800suspension & brakesadded · suspension & brakesT2–T4 subframe bushings now permitted to be replaced with non-spherical bushings of any material.
Every event the class ran, at any track, oldest to newest on the chart and newest first in the table. Each point is the class's best lap as a share of STL's best on the same day: the weather, the track and its configuration cancel out, so one figure compares across tracks and years where lap times cannot. It still moves when the yardstick's own balance changes or its field thins, and an event the yardstick did not run has no point. A best from fewer than three cars is greyed. The rule changes that took effect between two events are folded between their rows.