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BoP Lab / Virginia International Raceway

STU vs AS pace at Virginia International Raceway

Class · click a class to switch, + to compare alongside (up to 4)
Series
Reference class · the others' laps as a share of this one's at the same event, so years compare despite weather; + a class above to measure against it

Quickest here: STU 1:59.948 Kevin Boehm, Runoffs 2019 qualifying · AS 2:02.162 Kurt Rezzetano, Runoffs 2022 qualifying

2:002:052:102:152:202:252:302:3589 rule changes between Runoffs 2019 and Runoffs 202289 ▾7 rule changes between Runoffs 2022 and Runoffs 20237 ▾STU race best at Runoffs 2019: 2:00.483 (Kevin Boehm)STU race best at Runoffs 2022: 2:32.357 (Mark Liller)STU race best at Runoffs 2023: 2:02.302 (Mark Liller)STU qualifying best at Runoffs 2019: 1:59.948 (Kevin Boehm)STU qualifying best at Runoffs 2022: 2:00.615 (Johan Schwartz)AS race best at Runoffs 2019: 2:03.900 (James Jost)AS race best at Runoffs 2022: 2:04.578 (Gregory Eaton)AS race best at Runoffs 2023: 2:04.120 (Gregory Eaton)AS qualifying best at Runoffs 2019: 2:02.938 (Gregory Eaton)AS qualifying best at Runoffs 2022: 2:02.162 (Kurt Rezzetano)Runoffs 20192019Runoffs 20222022Runoffs 20232023
STUASsolid race · dashed qualifying · slower is lower
80%82%84%86%88%90%92%94%96%98%100%102%104%89 rule changes between Runoffs 2019 and Runoffs 202289 ▾7 rule changes between Runoffs 2022 and Runoffs 20237 ▾STU race best at Runoffs 2019: 100.0% of STU's (Kevin Boehm)STU race best at Runoffs 2022: 100.0% of STU's (Mark Liller)STU race best at Runoffs 2023: 100.0% of STU's (Mark Liller)STU qualifying best at Runoffs 2019: 100.0% of STU's (Kevin Boehm)STU qualifying best at Runoffs 2022: 100.0% of STU's (Johan Schwartz)AS race best at Runoffs 2019: 102.8% of STU's (James Jost)AS race best at Runoffs 2022: 81.8% of STU's (Gregory Eaton)AS race best at Runoffs 2023: 101.5% of STU's (Gregory Eaton)AS qualifying best at Runoffs 2019: 102.5% of STU's (Gregory Eaton)AS qualifying best at Runoffs 2022: 101.3% of STU's (Kurt Rezzetano)Runoffs 20192019Runoffs 20222022Runoffs 20232023
STUASsolid race · dashed qualifying · each class's best lap as a share of STU's at the same event (the reference class, changeable above); 100% is level, higher is quicker
EventSTUAS
Qual bestRace bestTrapQual bestRace bestTrapvs STU% of STU
Runoffs 2023 ROFF232023-09-232:02.302Mark Liller · fastest of 14 · top 5 within 1.6s-30.055s (-19.73%)144.0Mark Liller+0.1 mph (+0.1%)2:04.120Gregory Eaton · fastest of 9 · top 5 within 3.0s-0.458s (-0.37%)147.7Amy Aquilante-3.2 mph (-2.1%)+1.818s101.5%
7 rule changes (STU: 3, AS: 4)1 cars added · 1 tyres & wheels · 1 weight · 4 wording · AS crate motor part number specified: GM Performance CT400 P/N 19370604 engine assembly for GM vehicles. · AS Spec Lines Ford Mustang GT 5.0L (15-17) max wheel size increases to 19.0 inches. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 now permits SPC-66045 alternate front upper control arms. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front brake caliper adapters for updated or backdated components. · Toyota GR Cup and GR86 Cup (2022-) newly classified in STU at 2700 lbs with 2387 cc engine. · STU Mazda BP5A classified at 1839 cc maximum displacement, 2023-04-01. · STU minimum weight chart updated: 2450cc to 2595lbs, 2600cc to 2710lbs.showhide
  • AS Crate Motor Part Numbers #32944wordingneutralAS crate motor part number specified: GM Performance CT400 P/N 19370604 engine assembly for GM vehicles.
  • AS Request wheel size change #33007tyres & wheelsfasterAS Spec Lines Ford Mustang GT 5.0L (15-17) max wheel size increases to 19.0 inches.
  • AS Alternative Upper Front Control Arms for Dodge Challenger #33352wordingneutralAS Dodge Challenger 5.7L/6.1L/6.4L V8 now permits SPC-66045 alternate front upper control arms.
  • AS Front Brake Caliper Adapters for Dodge Challenger #33353wordingneutralAS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front brake caliper adapters for updated or backdated components.
  • STU 2022 Toyota GR Cup for STU #34449cars addedneutralToyota GR Cup and GR86 Cup (2022-) newly classified in STU at 2700 lbs with 2387 cc engine.
  • STU Alternate OEM Miata Intake Manifold #33827wordingneutralSTU Mazda BP5A classified at 1839 cc maximum displacement, 2023-04-01.
  • STU E&O STU NA Weight Chart. #33737weightfasterSTU minimum weight chart updated: 2450cc to 2595lbs, 2600cc to 2710lbs.
Runoffs 2022 ROFF222022-09-242:00.615Johan 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%)2:02.162Kurt Rezzetano · fastest of 13 · top 5 within 2.3s-0.776s (-0.63%)2:04.578Gregory Eaton · fastest of 11 · top 5 within 2.9s+0.678s (+0.55%)150.9James Jost-3.0 mph (-2.0%)-27.779squal +1.547s81.8%qual 101.3%
89 rule changes (STU: 50, AS: 39)17 weight · 13 engine · 9 cars added · 5 tyres & wheels · 4 suspension & brakes · 3 aero · 3 induction · 34 wording · 1 other · AS allows Hoosier W2 tyre option in addition to R7, R6, WET/H20. · AS Dodge Challenger 08-20 adds two transmission ratio options: 2.97, 2.10, 1.45, 1.00, 0.74, 0.50 or 2.26, 1.58, 1.19, 1.00, 0.77, 0.63. · STU Mazda 13B Turbo classified, streetport only, stock turbos prohibited, alternatives allowed. · STU OEM louver vents now exempt from vent count and 200 square inch allowance. · STU 2400cc non-4-valve engines gain 9% base weight reduction; DI turbo prep limits removed. · AS Cadillac CTS-V 6.0L V8 removes 50 lbs weight penalty for 295 tire size. · STU normally-aspirated 2976–3200 cc single-throttle engines lose 10% base engine weight reduction. · ST redundant language removed from balance shaft and pulley modification rules. · STU cars that qualified for 9 inch wheels in 2021 may continue through 2022 only. · STU splitter definition clarified: must be single-plane with no vertical deviations, attached to lowest front point. · STU BMW S52B32 minimum weight drops 90 lbs to 3110; max displacement cut to 3152 cc. · STU BMW S50B32 Euro classified at 3201 cc displacement, 3300 lbs minimum weight. · ST engine swap origin country requirement changes from North America to the United States for case-by-case approval. · STU Honda CRX (84-91) and Civic Del Sol (93-97) ineligible for front wheel drive weight reductions. · STU vehicles at or over 2950 lbs base weight may use 9 inch wide wheels instead of 8.0 inch maximum. · STU minimum weights reduced: 2450cc to 2596 lbs, 2500cc to 2635 lbs, 2550cc to 2675 lbs. · STU normally aspirated engines: minimum weights reduced up to 310 lbs; single throttle body weight reduction removed. · STU Audi A4 1.8T minimum weight fixed at 3050 lbs, VF30 turbo with 35mm restrictor now required only. · STL and STU Improved Touring vehicles must conform to 9.1.4 Tires & Wheels requirements. · STU engines may delete balance shafts and plug openings; alternate pulleys allowed for timing belt or chain operation only. · STU hood vents allowed to include louvers within 200 sq. inch area. · SMG long tube headers: Borla PN 17237 discontinued, Kooks PN 11312000 and American Racing PN MT3-05134300LSNC approved alternatives. · AS Mercury Capri (79-86) removed as individual spec line, merged into Ford Mustang (79-93) spec line. · AS Spec Mustang SMG loses 3.73 gear ratio and 355/300 mm brake specification. · AS Chevrolet, Pontiac, Ford full prep engines now permit alternate cylinder heads with restrictor plate ALL26180 and 1.250 inserts ALL26186 for regional competition. · STU adds Honda K23 with 2354cc displacement and minimum weight per chart, K24 block allowed with K23 internals and head. · STU Honda K23 internals rule relaxed to require only K23 crankshaft, allowing other internal modifications. · STL and STU piston engines clarified: intake manifold and cylinder head porting remains free. · AS Chevrolet/Pontiac Camaro & Firebird 93-02 now allow BMR AA004 or UMI 2310 adjustable front upper control arms. · AS Pontiac GTO 04-06 LS1 to 3300 lbs, LS2 to 3350 lbs on 295 tire. · STU fender flare wording clarified: exterior contour of any wheel opening may not change opening size, location or shape from side view. · STU Mazda 12A Bridge Port Miata weight reduced from 2550 lbs to 2350 lbs. · AS Cadillac CTS-V 6.0L V8 removes 50 lbs tire size penalty, making it lighter. · AS consolidates seven SN95 Mustang spec lines into three: 94-04 including Cobra, 94-95 5.0/5.8, and 96-04 4.6L two/four valve. · AS Camaro/Firebird LT1/LS1 transmission code changes to 6362; Mustang GT 4.6L/5spd changes to 5.0L/6spd with 300 lbs weight reduction. · AS Camaro/Firebird and Mustang GT gear ratio specifications restored with alternate sets permitted. · AS Chevrolet Camaro & Firebird, Ford Mustang variants, Mercury Capri minimum weights increase 50 lbs across all model years. · STU fender flare rules clarified: maximum 2 inches, must cover tire contact patch from above, cannot alter body configuration or wheel opening geometry. · STU Honda S2000 allows F20/F22 K24 crankshaft with chart weight for achieved displacement. · ST oil coolers and filters now explicitly allowed to be added or substituted; wording clarifies existing permissions. · AS Mustang 4.6L/5spd loses 300 lbs; 5.0L/6spd gains 56mm restrictor requirement. · AS CTS-V LS6 and LS2 may now use Driveshaft Shop carbon fiber driveshaft for durability. · AS Chevrolet Camaro SS V8 6.2L model years extended from 10-13 to 10-15. · STL/STU 90-05 Mazda Miata gains approval for Mazda Motorsports Development alternate front wheel hubs. · ST cars may relocate ABS actuation hardware and wiring anywhere in engine compartment. · STU Porsche PDK automatic transmission limited to 8 forward speeds instead of torque converter restriction. · STU Mazda 13B Street Port 2400 removes choke location restriction, allows auto-type 2bbl with dual-Y manifold. · STU driveshaft and half-shaft materials change from OEM-type to steel or aluminum. · Ford Mustang GT 5.0L 15-17 Restricted Preparation classified in AS with 55mm flat plate restrictor required. · AS underhood bracing on stock hoods, trunks, and rear decks may be modified or removed. · AS Cadillac CTS-V 04-07 with 295 tire drops to 3450 lbs; Camaro SS V8 10-13 275 tire removed; Challenger 08-20 gains 315 tire option at 3600 lbs. · AS Camaro & Firebird (93-02) and Mustang GT (05-14) specifications restored with 200 lb weight reduction for permitted heads. · STU Mazda 13B Street Port classified at 2400 lbs minimum weight, replacing peripheral and bridge port variants. · AS Dodge Challenger 08-20 gains 6.1L and 6.4L V8 options; 5.7L weight rises to 3500 lbs on 295 tyres, 3600 on 315 tyres. · AS Camaro/Firebird (93-02) and Mustang Coupe GT (05-14) consolidated into single specs with 100 lb and 300 lb weight reductions respectively. · ST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch. · STU fender flare rules reworded: up to 2" per corner allowed with 1% weight penalty total. · AS Dodge Challenger 5.7L V8 gets iron block requirement, 10.5:1 compression max, intake valve 12.7 mm, exhaust 12.3 mm, intake duration 188°, exhaust duration 205°. · AS Dodge Challenger 08-14 rear spoiler part number changes from 1GL20RXF to 1GL20TZZAB. · STL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis adjustments. · STL and STU rear wing rules clarify that wicker is a Gurney flap; no performance change. · AS class pursues specified list of eligible tires; details of tire changes not provided in letter. · AS class pursuing specified list of eligible tires; details pending further communication. · No restrictor plate change implemented; 2021 AS Mustang Coyote under evaluation. · AS 2005-2009 Restricted Prep 4.6 3V now permits conversion to 2 valve configuration. · AS Ford Mustang Coupe GT 4.6L 3V Restricted Prep now permits Ford Performance camshaft kit P/N-M-6550-3V. · 2010-2014 Camaro reclassified to AS; full preparation classification approved effective 2020-07-01. · AS class cylinder head replacement options under review; implementation planned for 2021 season. · AS Mustang, Camaro, Firebird, Capri max brake rotor diameter increases from 12.2 to 13.1 inches. · AS rotor diameter increase approved; see Fastrack letter #28748 for details. · STU request for alternate intake manifold denied; no rule change issued. · GT3 and STU add Borg-Warner EFR6258 to approved turbocharger list. · STU large displacement turbo engines limited by GCR turbo list; non-turbo trim suggested as more competitive. · STU sequential shifters referred to Board of Directors for approval; no change implemented yet. · STU Mazda 13B Bridge Port and Street Port engines added with 2550 and 2250 lbs minimum weights respectively. · AS Chevrolet/Pontiac Camaro & Firebird (82-92) loses 50 lbs, to 3500. · STU Honda S2000 adds HKS Supercharger kits 12001-AH006 and 12001-AH010 as allowed. · STU Lotus Elise Cup R and SC models, plus Exige SC, gain 100–200 lbs minimum weight. · STU Volkswagen GTI/GLI MK5 and Jetta Mk4 may install turbo inlet restrictor in OEM turbo inlet housing. · STU Honda K20C1 Turbo I4 restrictor reduces from 36mm to 35mm. · STU GM Ecotech LNF now allowed with turbo removed or 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. · STU vehicles over 2951 lbs base weight may use 9 inch wide wheels, up from 2950 lbs. · STU turbocharged engines now use base weight instead of minimum weight, with 3% DI increase applied to base weight. · AS rear trailing arms may be replaced with tubular arms maintaining stock length and axle location purpose only. · AS Ford and GM full-prep cars get 200 lb weight reduction, up from 150 lb. · 05-10 Ford Mustang Coupe GT 4.6L OHC classified AS with 3200 lbs minimum weight, HR cam restricted prep. · AS 10-15 Chevrolet Camaro Full Prep classified with 3400 lbs base weight, over 313 CID engine 3700 lbs maximum. · STU cars with manual OEM throttle bodies may convert to OEM electronic throttle body of same inner diameter.showhide
  • AS Request to add Hoosier W2 #33031tyres & wheelsneutralAS allows Hoosier W2 tyre option in addition to R7, R6, WET/H20.
  • AS correction of Dodge Challenger specification line #33151wordingneutralAS Dodge Challenger 08-20 adds two transmission ratio options: 2.97, 2.10, 1.45, 1.00, 0.74, 0.50 or 2.26, 1.58, 1.19, 1.00, 0.77, 0.63.
  • STU Request Mazda 13 B turbo #32668cars addedneutralSTU Mazda 13B Turbo classified, streetport only, stock turbos prohibited, alternatives allowed.
  • STU Hood Vents and Intercooler Scoops #32733aerofasterSTU OEM louver vents now exempt from vent count and 200 square inch allowance.
  • STU Non 4 valve weight reduction removed #32808enginefasterSTU 2400cc non-4-valve engines gain 9% base weight reduction; DI turbo prep limits removed.
  • AS Request CTS-V Spec Line Error Correction #30242weightfasterAS Cadillac CTS-V 6.0L V8 removes 50 lbs weight penalty for 295 tire size.
  • STU Error in new minimum weight table when combined with other text #32711engineslowerSTU normally-aspirated 2976–3200 cc single-throttle engines lose 10% base engine weight reduction.
  • STU Redundant Language in May GCR #32713wordingneutralST redundant language removed from balance shaft and pulley modification rules.
  • STU Opposed to the Proposed STU Weight Chart #32381wordingneutralSTU cars that qualified for 9 inch wheels in 2021 may continue through 2022 only.
  • STU Clarification request for GCR 9.1.4.D.3.a Splitter Definition #32414wordingneutralSTU splitter definition clarified: must be single-plane with no vertical deviations, attached to lowest front point.
  • STU Request Adjustment to Min Weight for STU BMW E36 M3 (95-99) #31535weight -90 lbsfasterSTU BMW S52B32 minimum weight drops 90 lbs to 3110; max displacement cut to 3152 cc.
  • STU BMW E36 M3 Canadian (North American) S50B32 engine #31866cars addedneutralSTU BMW S50B32 Euro classified at 3201 cc displacement, 3300 lbs minimum weight.
  • STU Engine Swap Origin Country #32209wordingneutralST engine swap origin country requirement changes from North America to the United States for case-by-case approval.
  • STU CRX/Civic Del Sol #32214weightslowerSTU Honda CRX (84-91) and Civic Del Sol (93-97) ineligible for front wheel drive weight reductions.
  • STU Error correction #32383tyres & wheelsfasterSTU vehicles at or over 2950 lbs base weight may use 9 inch wide wheels instead of 8.0 inch maximum.
  • STU Single TB Weight Modifiers Add to Chart #32393weightfasterSTU minimum weights reduced: 2450cc to 2596 lbs, 2500cc to 2635 lbs, 2550cc to 2675 lbs.
  • STU Single TB Weight Modifiers #31449weightfasterSTU normally aspirated engines: minimum weights reduced up to 310 lbs; single throttle body weight reduction removed.
  • STU Request to Remove A4 1.8t from STU Spec Line Tables #31465weightslowerSTU Audi A4 1.8T minimum weight fixed at 3050 lbs, VF30 turbo with 35mm restrictor now required only.
  • STU Improved Touring Tires #32063tyres & wheelsneutralSTL and STU Improved Touring vehicles must conform to 9.1.4 Tires & Wheels requirements.
  • STU Request Allowance for Balance Shaft Delete in STU #31434enginefasterSTU engines may delete balance shafts and plug openings; alternate pulleys allowed for timing belt or chain operation only.
  • STU Request Louvers in hood vents #31916aeroneutralSTU hood vents allowed to include louvers within 200 sq. inch area.
  • AS Proposed Revisions to SCCA GCR 2021 Appendix M, Part 3 #30295wordingneutralSMG long tube headers: Borla PN 17237 discontinued, Kooks PN 11312000 and American Racing PN MT3-05134300LSNC approved alternatives.
  • AS specification line consolidation and correction #31846wordingneutralAS Mercury Capri (79-86) removed as individual spec line, merged into Ford Mustang (79-93) spec line.
  • AS correction of SMG specification line #31847wordingunclearAS Spec Mustang SMG loses 3.73 gear ratio and 355/300 mm brake specification.
  • AS Alternate cylinder heads for full prep engine builds - Evaluation #31851engineunclearAS Chevrolet, Pontiac, Ford full prep engines now permit alternate cylinder heads with restrictor plate ALL26180 and 1.250 inserts ALL26186 for regional competition.
  • STU Request to Add Honda K23 Spec Line #30682cars addedneutralSTU adds Honda K23 with 2354cc displacement and minimum weight per chart, K24 block allowed with K23 internals and head.
  • STU RE: Aug FT letter 30682 #31060enginefasterSTU Honda K23 internals rule relaxed to require only K23 crankshaft, allowing other internal modifications.
  • STU Throttling Device Clarification #31323wordingneutralSTL and STU piston engines clarified: intake manifold and cylinder head porting remains free.
  • AS Request for adjustable Front Upper Control Arms on 4th Gen F-Body #30457suspension & brakesneutralAS Chevrolet/Pontiac Camaro & Firebird 93-02 now allow BMR AA004 or UMI 2310 adjustable front upper control arms.
  • AS Request Pontiac GTO tire size change #30881weightslowerAS Pontiac GTO 04-06 LS1 to 3300 lbs, LS2 to 3350 lbs on 295 tire.
  • STU STU Fender flares #30696wordingneutralSTU fender flare wording clarified: exterior contour of any wheel opening may not change opening size, location or shape from side view.
  • STU Request weight reduction for 12A bridgeport motor in Miata #30751weight -200 lbsfasterSTU Mazda 12A Bridge Port Miata weight reduced from 2550 lbs to 2350 lbs.
  • AS Request CTS-V Spec Line Error Correction #30242weightfasterAS Cadillac CTS-V 6.0L V8 removes 50 lbs tire size penalty, making it lighter.
  • AS Request to consolidate SN95 Mustang '94-'04 Mustang spec lines #30428wordingneutralAS consolidates seven SN95 Mustang spec lines into three: 94-04 including Cobra, 94-95 5.0/5.8, and 96-04 4.6L two/four valve.
  • AS American Sedan Transmission Rule Change Request #30595enginefasterAS Camaro/Firebird LT1/LS1 transmission code changes to 6362; Mustang GT 4.6L/5spd changes to 5.0L/6spd with 300 lbs weight reduction.
  • AS Correction to specifications inadvertently deleted #30691wordingneutralAS Camaro/Firebird and Mustang GT gear ratio specifications restored with alternate sets permitted.
  • AS weight adjustments #30700weight +50 lbsslowerAS Chevrolet Camaro & Firebird, Ford Mustang variants, Mercury Capri minimum weights increase 50 lbs across all model years.
  • STU Request for Fender Flare Clarification #30375wordingneutralSTU fender flare rules clarified: maximum 2 inches, must cover tire contact patch from above, cannot alter body configuration or wheel opening geometry.
  • STU Provision for Interchangeable Engine Components Already Allowed #30342engineunclearSTU Honda S2000 allows F20/F22 K24 crankshaft with chart weight for achieved displacement.
  • STU ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wordingneutralST oil coolers and filters now explicitly allowed to be added or substituted; wording clarifies existing permissions.
  • AS AS Mustang LP 4.6 3V Classification Transmission Request #29886weightfasterAS Mustang 4.6L/5spd loses 300 lbs; 5.0L/6spd gains 56mm restrictor requirement.
  • AS Request CF driveshaft on CTS-V for durability improvement #30117otherneutralAS CTS-V LS6 and LS2 may now use Driveshaft Shop carbon fiber driveshaft for durability.
  • AS Adjustment to model years of 5th generation RP Camaro #30348wordingneutralAS Chevrolet Camaro SS V8 6.2L model years extended from 10-13 to 10-15.
  • STU Super Touring Alternate Miata Hubs #30345wordingneutralSTL/STU 90-05 Mazda Miata gains approval for Mazda Motorsports Development alternate front wheel hubs.
  • STU Brake Component Relocation #29990wordingneutralST cars may relocate ABS actuation hardware and wiring anywhere in engine compartment.
  • STU Porsche PDK #30081wordingneutralSTU Porsche PDK automatic transmission limited to 8 forward speeds instead of torque converter restriction.
  • STU Reference Letter #29333 Proposed STU 13B Spec Line Changes #30086inductionfasterSTU Mazda 13B Street Port 2400 removes choke location restriction, allows auto-type 2bbl with dual-Y manifold.
  • STU Drive Shaft Request #30087wordingneutralSTU driveshaft and half-shaft materials change from OEM-type to steel or aluminum.
  • AS Request for 2015 -2017 Ford Mustang Spec Line #29514cars addedneutralFord Mustang GT 5.0L 15-17 Restricted Preparation classified in AS with 55mm flat plate restrictor required.
  • AS Request Trunk lid / Rear Hatch clarification #29591wordingneutralAS underhood bracing on stock hoods, trunks, and rear decks may be modified or removed.
  • AS Common Weight for CTS-V Tire #29759weightfasterAS Cadillac CTS-V 04-07 with 295 tire drops to 3450 lbs; Camaro SS V8 10-13 275 tire removed; Challenger 08-20 gains 315 tire option at 3600 lbs.
  • AS Correction to specifications inadvertently deleted #30041weightfasterAS Camaro & Firebird (93-02) and Mustang GT (05-14) specifications restored with 200 lb weight reduction for permitted heads.
  • STU 13B Rules Adjustment #29333cars addedslowerSTU Mazda 13B Street Port classified at 2400 lbs minimum weight, replacing peripheral and bridge port variants.
  • AS Request Additional Engine Options for Dodge Challenger Spec Line #29543engineslowerAS Dodge Challenger 08-20 gains 6.1L and 6.4L V8 options; 5.7L weight rises to 3500 lbs on 295 tyres, 3600 on 315 tyres.
  • AS Rule simplification spec line communization #29824wordingfasterAS Camaro/Firebird (93-02) and Mustang Coupe GT (05-14) consolidated into single specs with 100 lb and 300 lb weight reductions respectively.
  • STU Request clarification on wing measurement #29640aeroneutralST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch.
  • STU Request for Advanced Aero Rule Wording Clarification. #29124wordingneutralSTU fender flare rules reworded: up to 2" per corner allowed with 1% weight penalty total.
  • AS Dodge Challenger AS Spec Line Clarification #28698engineslowerAS Dodge Challenger 5.7L V8 gets iron block requirement, 10.5:1 compression max, intake valve 12.7 mm, exhaust 12.3 mm, intake duration 188°, exhaust duration 205°.
  • AS Dodge Challenger AS Spec Line Clarification #2 #28699wordingneutralAS Dodge Challenger 08-14 rear spoiler part number changes from 1GL20RXF to 1GL20TZZAB.
  • STU Minimum Weight Determination #27695wordingneutralSTL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis adjustments.
  • STU ST Gurney flap Wicker clarification #29012wordingneutralSTL and STU rear wing rules clarify that wicker is a Gurney flap; no performance change.
  • AS Support for R-Type Specification Tires #27450tyres & wheelsunclearAS class pursues specified list of eligible tires; details of tire changes not provided in letter.
  • AS Spec Tire Request #27519tyres & wheelsunclearAS class pursuing specified list of eligible tires; details pending further communication.
  • AS Restrictor Plate Change for RP 2011+ Mustang with Coyote Engine #27675wordingunclearNo restrictor plate change implemented; 2021 AS Mustang Coyote under evaluation.
  • AS 2005-2009 Restricted Prep 4.6 3V #27908engineunclearAS 2005-2009 Restricted Prep 4.6 3V now permits conversion to 2 valve configuration.
  • AS Request for 2005-2009 Restricted Prep 4.6 3V Parts #27909wordingunclearAS Ford Mustang Coupe GT 4.6L 3V Restricted Prep now permits Ford Performance camshaft kit P/N-M-6550-3V.
  • AS Request for Full Preparation Classification for 2010-2014 Camaro #28030cars addedunclear2010-2014 Camaro reclassified to AS; full preparation classification approved effective 2020-07-01.
  • AS Cylinder Heads #28696wordingunclearAS class cylinder head replacement options under review; implementation planned for 2021 season.
  • AS Request for Max Rotor Diameter Change #28748suspension & brakesfasterAS Mustang, Camaro, Firebird, Capri max brake rotor diameter increases from 12.2 to 13.1 inches.
  • AS Request increase rotor diameter #28797suspension & brakesneutralAS rotor diameter increase approved; see Fastrack letter #28748 for details.
  • STU Request for Alternate Intake Manifold #26514wordingneutralSTU request for alternate intake manifold denied; no rule change issued.
  • STU Request for Addition to GT3 Approved Turbo List #27576wordingneutralGT3 and STU add Borg-Warner EFR6258 to approved turbocharger list.
  • STU Request BoP for my Car #29004wordingneutralSTU large displacement turbo engines limited by GCR turbo list; non-turbo trim suggested as more competitive.
  • STU Sequential Shifters in STU #29031wordingneutralSTU sequential shifters referred to Board of Directors for approval; no change implemented yet.
  • STU Rotary Help #27833cars addedneutralSTU Mazda 13B Bridge Port and Street Port engines added with 2550 and 2250 lbs minimum weights respectively.
  • AS weight adjustments for 2020 season #28785weight -50 lbsfasterAS Chevrolet/Pontiac Camaro & Firebird (82-92) loses 50 lbs, to 3500.
  • STU Request to approve Honda S2000 HKS supercharger #27281enginefasterSTU Honda S2000 adds HKS Supercharger kits 12001-AH006 and 12001-AH010 as allowed.
  • STU Request BoP on the Lotus #27637weight +100 lbsslowerSTU Lotus Elise Cup R and SC models, plus Exige SC, gain 100–200 lbs minimum weight.
  • STU Turbo Inlet Restrictor On MK5 Volkswagen #27704inductionslowerSTU Volkswagen GTI/GLI MK5 and Jetta Mk4 may install turbo inlet restrictor in OEM turbo inlet housing.
  • STU Honda K20C1 removal #27732inductionslowerSTU 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 #27884engineslowerSTU GM Ecotech LNF now allowed with turbo removed or with LE5 head and intake manifold, meeting STL specs.
  • STU Alternate Engine for Porsche 944 #28259engineunclearSTU Porsche 944 now permits VW/Audi 1.8L and 2.0L turbo engines as alternates.
  • STU Please Modify the STU Wheel Size Rule for Clarity #27694weightfasterSTU vehicles over 2951 lbs base weight may use 9 inch wide wheels, up from 2950 lbs.
  • STU Turbo Engine Cars Base Weight #28032wordingneutralSTU turbocharged engines now use base weight instead of minimum weight, with 3% DI increase applied to base weight.
  • AS Rear Trailing Arms #28007suspension & brakesneutralAS rear trailing arms may be replaced with tubular arms maintaining stock length and axle location purpose only.
  • AS Weight reduction for cars running iron heads #28010weightfasterAS Ford and GM full-prep cars get 200 lb weight reduction, up from 150 lb.
  • AS 05-10 Mustang with HR cam classification #28226cars addedneutral05-10 Ford Mustang Coupe GT 4.6L OHC classified AS with 3200 lbs minimum weight, HR cam restricted prep.
  • AS 10-15 Camaro Full Prep classification #28227cars addedneutralAS 10-15 Chevrolet Camaro Full Prep classified with 3400 lbs base weight, over 313 CID engine 3700 lbs maximum.
  • STU Request for an electronic throttle body #27342wordingneutralSTU cars with manual OEM throttle bodies may convert to OEM electronic throttle body of same inner diameter.
Runoffs 2019 ROFF192019-10-051:59.948Kevin Boehm · fastest of 25 · top 5 within 3.5s2:00.483Kevin Boehm · fastest of 25 · top 5 within 2.5s143.8Kevin Boehm2:02.938Gregory Eaton · fastest of 17 · top 5 within 0.8s2:03.900James Jost · fastest of 16 · top 5 within 2.1s153.9James Jost+3.417squal +2.990s102.8%qual 102.5%
26 earlier rule changes on record, in force before Runoffs 2019 (from 2019)6 cars added · 4 induction · 2 aero · 2 engine · 1 tyres & wheels · 1 weight · 10 wording · AS Spec Mustang (SMG) added as Restricted Prep class. · STU wing assembly wording corrected: no part higher than roof height. · AS class minimum ride height clarified to 5 inches measured at rocker panel, excluding seams and cladding. · STU Nissan SR20DET removes -2mm penalty in Table B. · STU alternate intake manifolds now allowed case-by-case instead of prohibited. · AS Ford Mustang (79-93) 313 CID and under loses 100 lbs to 3150; over 313 CID loses 100 lbs to 3450. · STU aftermarket side skirts must meet 3-inch ride height, no openings except jacks or side exhaust, no wider than fascias, not higher than door bottom, no chassis reinforcement. · STU fender flare wording clarified: each fender may be flared up to 2" for tire clearance with 1% weight penalty. · STL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld. · STU Mazda 13B Bridge Port may use ELITE ROTARY SHOP FD V2.0 intake manifold instead of stock. · STU Mazda MZR LF/L3/L5 may use Goodwin Part #61-2510 intake manifold with stock or Acura throttle body. · STU suspension rules clarified: alternate components from same manufacturer moved from section E to section D. · STU Honda/Acura B20 classified at 1973 cc, now permits VTEC B16 or B18 cylinder head and intake manifold. · STU flared fenders up to 2" with 1% weight penalty moved from base to Advanced Aero rules. · TCA Honda Civic Si (2017-) must run 37mm TIR maximum as of June 1, 2019. · STU BMW S54B32 OEM reclassified from E46 designation, 3246 cc, 3300 lbs minimum weight. · Honda Civic Si 2017- classified STU at 1500cc, 2800 lbs minimum with OEM engine and bodywork. · STU BMW E46 S54 OEM 3246cc added at 3300 lbs minimum weight, no Super Touring allowances. · STU Mazda 13B and 13B Bridge Port may use RE or REW housings and intake with turbo removed. · STU Honda K24 may use intake part #s 17100-RRB-A00 or 17100-PRB-A10. · STU Mazda 12A Bridge Port engine classified at 2550 lbs minimum weight with specified carburetor induction options. · STU World Challenge car weight calculation method removed; new basis unclear from text provided. · STU AWD cars no longer required to reduce restrictor 1 mm from table. · STU rear wing maximum cord length set to 12 inches, end plates to 72.0 square inches each. · AS Spec Mustang (SMG) newly classified with 107.1 wheelbase, 3.73 gears, 355mm front brakes, 300mm rear. · STU Honda K20C1 Turbo I4 1996cc added at 3025 lbs minimum weight with 36mm TIR.showhide
  • AS Request to add SMG to 9.1.6.B.1 AS Intent #27140cars addedneutralAS Spec Mustang (SMG) added as Restricted Prep class.
  • STU Request to correct E&O advanced aerodynamics #27290wordingneutralSTU wing assembly wording corrected: no part higher than roof height.
  • AS Request Ride Height Clarification #26598wordingneutralAS class minimum ride height clarified to 5 inches measured at rocker panel, excluding seams and cladding.
  • STU Remove -2mm penalty from SR20DET Nissan #26982enginefasterSTU Nissan SR20DET removes -2mm penalty in Table B.
  • STU Request clarification for manifold and throttle in STU #27004inductionfasterSTU alternate intake manifolds now allowed case-by-case instead of prohibited.
  • AS Request to Revert to 2017 Weights #25885weightfasterAS Ford Mustang (79-93) 313 CID and under loses 100 lbs to 3150; over 313 CID loses 100 lbs to 3450.
  • STU Request to clarify afterrmarket side skirts exhaust exit #26814wordingneutralSTU aftermarket side skirts must meet 3-inch ride height, no openings except jacks or side exhaust, no wider than fascias, not higher than door bottom, no chassis reinforcement.
  • STU Wheel Flare wording #26872wordingneutralSTU fender flare wording clarified: each fender may be flared up to 2" for tire clearance with 1% weight penalty.
  • STU Request Ride Height Clarification #26597wordingneutralSTL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld.
  • STU Request to Use Japanese Mazda 13b Intake Manifold #25790inductionfasterSTU Mazda 13B Bridge Port may use ELITE ROTARY SHOP FD V2.0 intake manifold instead of stock.
  • STU Request Alternate Intake for Mazda MZR In a Rear Wheel Drive App. #26352inductionunclearSTU Mazda MZR LF/L3/L5 may use Goodwin Part #61-2510 intake manifold with stock or Acura throttle body.
  • STU E&O Suspension #26424wordingneutralSTU suspension rules clarified: alternate components from same manufacturer moved from section E to section D.
  • STU Revisit B20 VTEC #26530enginefasterSTU Honda/Acura B20 classified at 1973 cc, now permits VTEC B16 or B18 cylinder head and intake manifold.
  • STU Move Flared Fenders to STU Advanced Aero #26564aeroneutralSTU flared fenders up to 2" with 1% weight penalty moved from base to Advanced Aero rules.
  • STU TCA Civic SI E&O #26606tyres & wheelsslowerTCA Honda Civic Si (2017-) must run 37mm TIR maximum as of June 1, 2019.
  • STU S54 Spec line #26620wordingneutralSTU BMW S54B32 OEM reclassified from E46 designation, 3246 cc, 3300 lbs minimum weight.
  • STU Request to Class Assignment for 2017 Civic #24287cars addedneutralHonda Civic Si 2017- classified STU at 1500cc, 2800 lbs minimum with OEM engine and bodywork.
  • STU Request to run E46 3246cc in STU #25126cars addedneutralSTU BMW E46 S54 OEM 3246cc added at 3300 lbs minimum weight, no Super Touring allowances.
  • STU Engine Classification for Rotary #25564wordingunclearSTU Mazda 13B and 13B Bridge Port may use RE or REW housings and intake with turbo removed.
  • STU K24/K20 Head Swap Clarification/Amendment #25899wordingneutralSTU Honda K24 may use intake part #s 17100-RRB-A00 or 17100-PRB-A10.
  • STU Request to Classify 12a Bridge Ported Rotary Engine #25985cars addedneutralSTU Mazda 12A Bridge Port engine classified at 2550 lbs minimum weight with specified carburetor induction options.
  • STU World Challenge Car Eligibility #26387wordingunclearSTU World Challenge car weight calculation method removed; new basis unclear from text provided.
  • STU Request a phone call for discussion regarding weight #26398inductionfasterSTU AWD cars no longer required to reduce restrictor 1 mm from table.
  • STU Advanced Aero E&O #26413aeroneutralSTU rear wing maximum cord length set to 12 inches, end plates to 72.0 square inches each.
  • AS SMG Mustang eligibility in American sedan #26224cars addedneutralAS Spec Mustang (SMG) newly classified with 107.1 wheelbase, 3.73 gears, 355mm front brakes, 300mm rear.
  • STU Request to Equalize Direct Injected Turbo Cars #24890cars addedneutralSTU Honda K20C1 Turbo I4 1996cc added at 3025 lbs minimum weight with 36mm TIR.

Best is the class's fastest lap in that event's qualifying or race sessions, with the driver who set it, how many cars set a time that session and how close the top five were; a best from fewer than three cars is greyed. With two or more classes, "vs" is the gap of each class's best to the first class's at the same event. "% of STU" is the class's best as a share of STU's best at the same event (100% is level, less is quicker): weather and track condition move every class together, so this compares across years where the raw times do not. It still breaks when STU's own field changes or one session was wet and another dry. Newest event first. The coloured figure under each value is the change from the previous event that has one (green is quicker, red slower). Whole laps only, so events with different sector layouts still compare. Weather and track condition are not accounted for.