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 · T2 1:31.563 Preston Calvert, Runoffs 2016 qualifying · P2 1:20.188 Jeff Shafer, Runoffs 2016 qualifying
STLT2P2solid race · dashed qualifying · slower is lower
STLT2P2solid 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%)
2:23.977Scotty 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%
2:10.606Greg Gyann · fastest of 11 · top 5 within 5.3s+3.201s (+2.51%)
2:09.441Mike Reupert · fastest of 11 · top 5 within 4.2s+1.119s (+0.87%)
155.0Matt Strand+2.4 mph (+1.6%)
-21.216squal -19.931s
85.9%qual 86.8%
30 rule changes (STL: 4, T2: 26)6 cars added · 6 weight · 3 engine · 2 aero · 2 induction · 2 suspension & brakes · 1 removed · 1 tyres & wheels · 5 wording · 2 other · T2-TCR all models gain 300 lbs minimum weight; splitter ride height 3.50 inches, chassis 4.0 inches. · 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). · 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. · 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. · STL adds Mazda BP 1.6, 1600cc, minimum weight 2160 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. · 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. · 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. · 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. · 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
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.
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).
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.
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.
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.
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.
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.
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.
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%)
2:23.351Kurt 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%
33 rule changes (STL: 3, T2: 29, P2: 1)6 cars added · 6 engine · 4 tyres & wheels · 4 weight · 1 induction · 1 removed · 6 wording · 5 other · 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. · STL Mazda MX5 Challenge minimum weight now references GCR 9.1.7.1; mandatory component spec list removed, alternative tires only allowed. · 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. · 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. · 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. · P2 2000 cc Pinto engine car minimum weight set to 1335 lbs. · STL STU Mazda Miata alternate front hubs Mazda Motorsports Development Part #0000-04-5HUB-S1 approved. · 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. · T2 Spec Corvette now allows 295 R compound DOT tire alternative to required Nankang NS-2R.showhide
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.
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.
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.
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.
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.
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.
P2 2000 cc Pinto Engine Car Weight #37187weightslower · weightP2 2000 cc Pinto engine car minimum weight set to 1335 lbs.
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.
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.
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%)
2:22.117Kurt 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%
2:07.405Bart Wolf · fastest of 14 · top 5 within 3.0s-1.109s (-0.86%)
2:08.322Bart Wolf · fastest of 13 · top 5 within 0.6s-1.471s (-1.13%)
152.5Lucian Pancea-0.6 mph (-0.4%)
-21.923squal -22.658s
85.4%qual 84.9%
40 rule changes (STL: 4, T2: 31, P2: 5)10 weight · 6 cars added · 5 engine · 4 suspension & brakes · 3 tyres & wheels · 2 aero · 1 induction · 8 wording · 1 other · 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. · P2 Spec Line E engine notes clarify oil system, ECU, and exhaust remain unrestricted; wording only. · P2 FIA Group CN notes clarify V de V European Proto Endurance Challenge bodywork, rear diffuser, wing, wheels, assisted shifting allowed; regulations link provided. · 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. · 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. · 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. · P2 AMAC and related cars: clarified B.1 modified engine range to 2008 and older stock engines only, with 38mm restrictor and 1025 lbs minimum weight. · P2 Suzuki GSX-R1000 engine: 2007–2008 crankcase 11300-21860 may be replaced with 2016–2019 GSX-S1000 part 11301-04840. · 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. · P2 Table 1 engine date ranges clarified: Stock Engine replaced with specific marques Suzuki, Yamaha, Honda, BMW for 2009-newer and 2008-older rows. · T2 BMW M2 CS Cup 2020- gains permission for hood vents conforming to 9.1.9.2.D.8.a.7.showhide
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.
P2 CN Spec ECU #35835wordingwordingP2 Spec Line E engine notes clarify oil system, ECU, and exhaust remain unrestricted; wording only.
P2 E&O - Correct FIA Group CN spec line notes #35900wordingwordingP2 FIA Group CN notes clarify V de V European Proto Endurance Challenge bodywork, rear diffuser, wing, wheels, assisted shifting allowed; regulations link provided.
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.
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.
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.
P2 E&O - Clarify B.1 modified engine range in AMAC spec lines #35225wordingwordingP2 AMAC and related cars: clarified B.1 modified engine range to 2008 and older stock engines only, with 38mm restrictor and 1025 lbs minimum weight.
P2 Replacement Engine Crankcase for 07/08 Suzuki GSX-R1000 Engines #35340engineadded · engineP2 Suzuki GSX-R1000 engine: 2007–2008 crankcase 11300-21860 may be replaced with 2016–2019 GSX-S1000 part 11301-04840.
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.
P2 Correct Table 1 for Engine Date Range Specifications #35182wordingwordingP2 Table 1 engine date ranges clarified: Stock Engine replaced with specific marques Suzuki, Yamaha, Honda, BMW for 2009-newer and 2008-older rows.
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%)
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%
1:48.590Greg Gyann · fastest of 12 · top 5 within 1.7s+1.024s (+0.95%)
1:48.829Lucian Pancea · fastest of 11 · top 5 within 0.9s-27.005s (-19.88%)
150.9Lucian Pancea-0.2 mph (-0.2%)
-17.853squal -17.189s
85.9%qual 86.3%
27 rule changes (STL: 2, T2: 17, P2: 8)5 suspension & brakes · 4 cars added · 4 engine · 2 weight · 1 aero · 1 tyres & wheels · 8 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. · 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. · P2 minimum side body height must equal front axle centerline height, viewed from side. · P2 closed cockpit single seat cars now prohibited unless Table 1 spec line permits. · T2 C5 Z06 with 56mm restrictor weighs 3425 lbs; 58mm restrictor option removed. · P2 engine table spec line B.1 redundant effective date language removed and table updated. · P2 motorcycle restrictor reduced 35mm to 34mm for 2011+ Kawasaki; minimum weights increased to 1100 lbs for 2009+ engines; cockpit length corrected to 23.622 inches. · 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. · 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. · Sebeco NP01-EVO and Elan NP01 added to P2 with Mazda 2.0L MZR, no restrictor required, 1600 lb minimum weight. · P2 Radical SR3/SR4, Cup, Club Sport, Pro-Sport, PR6: assisted shifting clarified from A-assisted to Aassisted; Cup engine restrictor changed from Unrestricted to Not required. · P2 chassis now allows composite materials partially installed; anti-intrusion panels attachment simplified; Stohr and converted models clarified. · 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.
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.
P2 Clarify minimum side body height requirement #34143wordingwordingP2 minimum side body height must equal front axle centerline height, viewed from side.
P2 Clarify closed cockpit single seat car allowance #34144wordingwordingP2 closed cockpit single seat cars now prohibited unless Table 1 spec line permits.
P2 Remove redundant effective date language and update engine table #34012wordingwordingP2 engine table spec line B.1 redundant effective date language removed and table updated.
P2 E&O - Correct dimensional equivalents #34038enginefaster · engineP2 motorcycle restrictor reduced 35mm to 34mm for 2011+ Kawasaki; minimum weights increased to 1100 lbs for 2009+ engines; cockpit length corrected to 23.622 inches.
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.
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.
P2 Request to Classify Sebeco NP01 #33378cars addedaddedSebeco NP01-EVO and Elan NP01 added to P2 with Mazda 2.0L MZR, no restrictor required, 1600 lb minimum weight.
P2 Radical spec line clarifications #33485wordingwordingP2 Radical SR3/SR4, Cup, Club Sport, Pro-Sport, PR6: assisted shifting clarified from A-assisted to Aassisted; Cup engine restrictor changed from Unrestricted to Not required.
P2 E&O original class intent #33519wordingwordingP2 chassis now allows composite materials partially installed; anti-intrusion panels attachment simplified; Stohr and converted models clarified.
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%)
2:00.276Kurt 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%
1:47.566Tim Day Jr · fastest of 12 · top 5 within 3.0s-1.545s (-1.42%)
2:15.834Greg Gyann · fastest of 12 · top 5 within 10.1s+25.576s (+23.20%)
151.1Robert Iversen+1.8 mph (+1.2%)
+8.002squal -17.908s
106.3%qual 85.7%
35 rule changes (STL: 5, T2: 20, P2: 10)6 cars added · 5 weight · 3 engine · 3 suspension & brakes · 1 aero · 1 induction · 1 tyres & wheels · 13 wording · 2 other · 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. · P2 chassis construction clarified: full composite allowed; partial composite must roll without composite parts installed. · P2 classification wording cleaned up in GCR section 9.1.8.C and GCR contents. · 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. · P2 Oldsmobile cam rules correct spelling from 'after market' to 'aftermarket' in two sections. · 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. · P2 adds Beasley B2 at 1350 lbs with Mazda 12A, 40.5mm venturi, and up to 16.5in wing chord. · P2 wings: terminology change from 'cord' to 'chord', and 'only' removed from Bobsy and Jondal notes. · P2 Converted F5 cars renamed F500, must retain F500 suspension, minimum width 55 inches. · 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. · 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. · P2 motorcycle engines gain 5cc to 1505cc max, two-stroke gains 5cc to 1205cc max, automotive engines add 50 lbs minimum weight to 1350 lbs. · T2 BMW Z4M 06-08 minimum weight reduced 50 lbs to 3100. · P2 Control Area definition clarified: rectangular zone from rear edge of front tires to front edge of rear tires, full car width. · 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. · 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. · P2 specification line B.1 engine table entry amended; details of change not provided in excerpt. · P2 Control Area definition clarified: rear tire edge and front tire edge bounds, car's lower surface width, floor extensions and aerodynamic attachments included, vertical structures prohibited. · 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
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.
P2 E&O Clarification of Chassis Construction Requirements #32469wordingwordingP2 chassis construction clarified: full composite allowed; partial composite must roll without composite parts installed.
P2 Clean up P2 wording #32525wordingwordingP2 classification wording cleaned up in GCR section 9.1.8.C and GCR contents.
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.
P2 After Market to Aftermarket #32373wordingwordingP2 Oldsmobile cam rules correct spelling from 'after market' to 'aftermarket' in two sections.
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.
P2 Add spec line for Beasley B2 #32147cars addedaddedP2 adds Beasley B2 at 1350 lbs with Mazda 12A, 40.5mm venturi, and up to 16.5in wing chord.
P2 E&O Table 1 spec line wing terminology #32148wordingwordingP2 wings: terminology change from 'cord' to 'chord', and 'only' removed from Bobsy and Jondal notes.
P2 E&O class name #32196wordingwordingP2 Converted F5 cars renamed F500, must retain F500 suspension, minimum width 55 inches.
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.
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.
P2 E&O Engine section #31969weightslower · weightP2 motorcycle engines gain 5cc to 1505cc max, two-stroke gains 5cc to 1205cc max, automotive engines add 50 lbs minimum weight to 1350 lbs.
T2 BMW Z4M Adjustment #31885weight -50 lbsfaster · weightT2 BMW Z4M 06-08 minimum weight reduced 50 lbs to 3100.
P2 E&O letter #31539 – Control Area definition #31783wordingwordingP2 Control Area definition clarified: rectangular zone from rear edge of front tires to front edge of rear tires, full car width.
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.
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.
P2 BoP adjustment effective 1-1-22 #31538otherunclearP2 specification line B.1 engine table entry amended; details of change not provided in excerpt.
P2 E&O clarification of "Control Area" definition #31539wordingwordingP2 Control Area definition clarified: rear tire edge and front tire edge bounds, car's lower surface width, floor extensions and aerodynamic attachments included, vertical structures prohibited.
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
1:47.509Kurt 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%
1:33.235Tim Day Jr · fastest of 16 · top 5 within 3.3s+1.409s (+1.53%)
1:35.322Tim Day Jr · fastest of 10 · top 5 within 4.8s+2.841s (+3.07%)
150.3Robert Iversen
-27.389squal -18.430s
77.7%qual 83.5%
53 rule changes (STL: 15, T2: 30, P2: 8)14 cars added · 8 weight · 5 engine · 4 induction · 3 suspension & brakes · 2 aero · 1 tyres & wheels · 12 wording · 4 other · P2 CN Honda K20A-FD2 engine rebuild clarified: balancing, porting, polishing prohibited; valve jobs and honing must follow factory procedures. · 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. · P2 Converted F5 cars must retain F5 suspension and meet P2 non-spec requirements except minimum width is 55 inches. · P2 minimum body width clarified: cannot extend inward beyond vertical plane through tire centerlines. · T2 Porsche 911/997.1 (06–08) now permits Cargraphics CARP97DFIFKR alternate exhaust manifold. · 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. · P2 tonneau covers now allowed to meet minimum dimensions; cockpit equipment attachment wording clarified. · P2 removes effective date 01/01/2021 from six car spec lines in Table 1. · P2 engine specs B.1, B.2, B.3 limited to maximum 4 valves per cylinder. · 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. · 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. · 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. · P2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front, 14–15 rear wheel width. · 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. · 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. · 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. · 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. · P2 motorcycle-engine cars: 2009+ stock 37mm restrictor, 2008- stock 35mm, modified 1075 lbs. Honda K20A 50mm restrictor. Various spec cars: restrictors increased or decreased 0.5–3mm. · 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
P2 P2 CN Engine Rebuild Clarification #31000wordingwordingP2 CN Honda K20A-FD2 engine rebuild clarified: balancing, porting, polishing prohibited; valve jobs and honing must follow factory procedures.
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.
P2 F5 P2 Conversion #30856wordingwordingP2 Converted F5 cars must retain F5 suspension and meet P2 non-spec requirements except minimum width is 55 inches.
P2 Clarify minimum body width requirement #30859wordingwordingP2 minimum body width clarified: cannot extend inward beyond vertical plane through tire centerlines.
T2 997.1 EO #30933cars addedaddedT2 Porsche 911/997.1 (06–08) now permits Cargraphics CARP97DFIFKR alternate exhaust manifold.
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.
P2 E&O tonneau cover provision in cockpit opening section #30459wordingwordingP2 tonneau covers now allowed to meet minimum dimensions; cockpit equipment attachment wording clarified.
P2 Remove effective dates in Table 1 #30468wordingwordingP2 removes effective date 01/01/2021 from six car spec lines in Table 1.
P2 E&O Maximum Valves Per Cylinder #30560engineengineP2 engine specs B.1, B.2, B.3 limited to maximum 4 valves per cylinder.
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.
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.
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.
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.
P2 Add a new spec line for a 2-cycle, 3-cylinder engine up to 820cc #30272cars addedaddedP2 adds new spec line for 2-cycle 3-cylinder engine up to 820cc with 10 front, 14–15 rear wheel width.
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.
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.
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.
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.
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
2:24.195Alan 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%
2:08.514Robert Iversen · fastest of 12 · top 5 within 3.0s
2:09.793Robert Iversen · fastest of 12 · top 5 within 3.9s
153.1Robert Iversen
-22.322squal -22.906s
85.3%qual 84.9%
47 rule changes (STL: 11, T2: 30, P2: 6)12 cars added · 7 weight · 6 suspension & brakes · 5 engine · 2 aero · 1 induction · 1 tyres & wheels · 8 wording · 5 other · 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. · P2 rear wing rules clarified: standard wing 6×12 inches, end plates 14-inch square; alternate 1-meter formula wing 110cm wide, 9×18 inches, end plates 14×18 inches. · 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. · 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. · 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. · Elan NP01 added to P2 Table 1 as Spec Line car with 2000cc displacement and 42mm restrictor. · 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. · 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. · P2 Enterprises Sports Racer now permits 55mm flat plate intake restrictor Part # WM303013 as alternative to SIR. · 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. · P2 Enterprise Sports Racer 2.3L engine must use SIR or Flat Plate restrictor meeting peak horsepower, sized in whole or 0.5mm increments. · 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. · 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. · P2 electronic throttle control wording clarified: ETC permitted if stock ECU throttle pedal activates original throttle shaft mechanism. · STL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL to notes. · 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. · P2 adds BMW to permitted motorcycle-based engines alongside Kawasaki, Suzuki, Yamaha, Honda. · 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.showhide
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.
P2 E&O clarification of P2 rear wing requirements #29205aeroaeroP2 rear wing rules clarified: standard wing 6×12 inches, end plates 14-inch square; alternate 1-meter formula wing 110cm wide, 9×18 inches, end plates 14×18 inches.
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.
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.
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.
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.
P2 Classify Elan NP01 in P2 Table 1 #28812cars addedaddedElan NP01 added to P2 Table 1 as Spec Line car with 2000cc displacement and 42mm restrictor.
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.
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.
P2 SCCA Enterprises ESR / P2 engine restrictor testing #28669otheraddedP2 Enterprises Sports Racer now permits 55mm flat plate intake restrictor Part # WM303013 as alternative to SIR.
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.
P2 Add ESR inlet restrictor #27869inductionadded · inductionP2 Enterprise Sports Racer 2.3L engine must use SIR or Flat Plate restrictor meeting peak horsepower, sized in whole or 0.5mm increments.
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.
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.
P2 Request for Fly by Wire Rule Wording Change #28247wordingwordingP2 electronic throttle control wording clarified: ETC permitted if stock ECU throttle pedal activates original throttle shaft mechanism.
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.
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.
P2 Request for addition of BMW Engine in P2 Engine Table #27821engineadded · engineP2 adds BMW to permitted motorcycle-based engines alongside Kawasaki, Suzuki, Yamaha, Honda.
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.
2:07.203Danny Steyn · fastest of 36 · top 5 within 1.8s
2:07.273Cliff Ira · fastest of 35 · top 5 within 1.4s
134.8Cliff Ira
1:57.537Cooper 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%
1:49.111Robert Iversen · fastest of 14 · top 5 within 0.8s
1:50.258Greg Gyann · fastest of 13 · top 5 within 0.4s
149.4Robert Iversen
-17.015squal -18.092s
86.6%qual 85.8%
43 rule changes (STL: 11, T2: 23, P2: 9)10 cars added · 8 engine · 7 suspension & brakes · 4 weight · 2 induction · 1 aero · 1 tyres & wheels · 8 wording · 2 other · P2 Honda K20A-FD2 non-composite chassis intake restrictor note clarified; restrictor implementation date removed. · STL adds Mazda Spec MX-5 Challenge, 2000cc displacement, 2500 lb minimum weight, with mandatory Roush, Penske, Eibach, and other specified components. · P2 motorcycle engines: Stock restrictor to 35mm, Modified to 34mm; weights up to 1025 and 1125 lbs respectively. B.5 restrictor to 33mm, weight to 1185 lbs. · T2, T3, T4 spare tire and cover removal wording clarified; removable covers now explicitly allowable to remove. · P2 cars limited to power application on maximum two wheels. · 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. · P2 Enterprise minimum weight increased to 1375 lbs.; peak horsepower of sealed ESR engine reduced per CRB specification. · STL Acura/Honda B18 except C engine restrictor increased from 53mm to 54mm flat plate. · 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. · T2 Mustang GT rear anti-roll bar may now be removed or disconnected. · P2 stock and modified engines get smaller restrictors (35.0mm, 34.0mm, 33.0mm) and heavier minimums (1025, 1125, 1185 lbs). · P2 Line A.1 restrictor reduced from 40mm to 38mm. · 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. · 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. · P2 Spec Line cars now allow 1345cc Hayabusa stock engines at 1050 lb minimum with 30mm restrictor. · P2 Group CN Honda K20A-FD2 55mm intake restrictor implementation delayed from 1 January to 3 March 2019. · P2 Honda K20A-FD2 Group CN must use stock intake manifold, 64mm throttle, 55mm restrictor at 1500 lbs minimum. · 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. · 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
P2 Update Engine Table Line E notes #27414wordingwordingP2 Honda K20A-FD2 non-composite chassis intake restrictor note clarified; restrictor implementation date removed.
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.
P2 Update P2 Engine Table spec lines to reflect 3/1/2019 #27254engineslower · engineP2 motorcycle engines: Stock restrictor to 35mm, Modified to 34mm; weights up to 1025 and 1125 lbs respectively. B.5 restrictor to 33mm, weight to 1185 lbs.
T2 Request spare tire/wheel clarification #27012wordingfasterT2, T3, T4 spare tire and cover removal wording clarified; removable covers now explicitly allowable to remove.
P2 E&O Transmissions #27006engineslower · engineP2 cars limited to power application on maximum two wheels.
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.
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.
P2 Request to restrict all cars #26246weightslower · weightP2 Enterprise minimum weight increased to 1375 lbs.; peak horsepower of sealed ESR engine reduced per CRB specification.
STL Request Restrictor Plate correction #26779enginefaster · engineSTL Acura/Honda B18 except C engine restrictor increased from 53mm to 54mm flat plate.
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.
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.
P2 Change Engine Table Lines B.1 & B.5 #25777inductionslower · inductionP2 stock and modified engines get smaller restrictors (35.0mm, 34.0mm, 33.0mm) and heavier minimums (1025, 1125, 1185 lbs).
P2 Change Line A.1 restrictor size #26429engineslower · engineP2 Line A.1 restrictor reduced from 40mm to 38mm.
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.
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.
P2 Request to Allow 1345cc Hayabusa Engines for Spec Line P2 Cars #25595cars addedaddedP2 Spec Line cars now allow 1345cc Hayabusa stock engines at 1050 lb minimum with 30mm restrictor.
P2 Change CN inlet restrictor implementation date #25816wordingwordingP2 Group CN Honda K20A-FD2 55mm intake restrictor implementation delayed from 1 January to 3 March 2019.
P2 Clarify Honda K20A-FD2 parts requirement #25950engineslower · engineP2 Honda K20A-FD2 Group CN must use stock intake manifold, 64mm throttle, 55mm restrictor at 1500 lbs minimum.
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.
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.