BoP Lab / Michelin Raceway Road Atlanta

STL vs F6 vs SM vs F5 pace at Michelin Raceway Road Atlanta

Quickest here: STL 1:35.212 Danny Steyn, Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta race · F6 1:30.014 Clint McMahan, Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta qualifying · SM 1:41.798 Danny Steyn, Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta qualifying · F5 1:30.019 Ryan Mayfield, Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta qualifying

Lap times% of STL

STLF6SMF5solid race · dashed qualifying · slower is lower

STLF6SMF5solid 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, higher is quicker

	Event	STL			F6					SM					F5
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs STL	% of STL	Qual best	Race best	Trap	vs STL	% of STL	Qual best	Race best	Trap	vs STL	% of STL
	Atlanta Region SCCA Hoosier Super Tour @ Michelin Raceway Road Atlanta ST26MAR062026-03-06	1:37.000Danny Steyn · fastest of 15 · top 5 within 1.6s+0.012s (+0.01%)	1:36.825Danny Steyn · fastest of 14 · top 5 within 3.2s-0.382s (-0.39%)	126.5Derek Ketchie+6.5 mph (+5.4%)	1:30.039Calvin Stewart · fastest of 4 · top 4 within 13.3s+0.025s (+0.03%)	1:33.719H Cory Mcleod · fastest of 3 · top 3 within 14.2s+3.452s (+3.82%)	137.8Calvin Stewart+5.7 mph (+4.3%)	-3.106squal -6.961s	96.8%qual 92.8%	1:42.324Skyler Cottrell · fastest of 52 · top 5 within 0.4s-0.524s (-0.51%)	1:42.611Charles Mactutus · fastest of 51 · top 5 within 0.2s-0.014s (-0.01%)	112.2James Newell+5.2 mph (+4.9%)	+5.786squal +5.324s	106.0%qual 105.5%
6 rule changes (STL: 3, SM: 3)2 weight · 4 wording · STL minimum weights increase across all classes, 1300 cc gains 195 lbs to 1950, up to 1850 cc at 2500. · STL/STU Lotus weight reduced: Evora GT4 to 2700 lbs, Elise Cup R to 2250 lbs, Elise/Exige SC to 2450-2550 lbs. · SMX drivers must submit data acquisition files on time or face suspension and $250 fine. · SMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fine; level 2 and 4 may carry $500 fine. · SM cars limited to one set of Hoosier SM 7.5 P205/50/ZR17 per Super Tour event weekend for dry sessions. · STL Mazda MX5 Challenge minimum weight now references GCR 9.1.7.1 instead of 2500 lbs; spec components removed, only alternative tires allowed.showhide 2026-01-01 STL Weight adjustment for STL #39579weightslowerSTL minimum weights increase across all classes, 1300 cc gains 195 lbs to 1950, up to 1850 cc at 2500. 2025-08-01 STL Lotus Weight Reduction #38772weight -50 lbsfasterSTL/STU Lotus weight reduced: Evora GT4 to 2700 lbs, Elise Cup R to 2250 lbs, Elise/Exige SC to 2450-2550 lbs. 2025-06-01 SM SMX Data Submission - Penalties #38248wordingwordingSMX drivers must submit data acquisition files on time or face suspension and $250 fine. 2025-06-01 SM Committee) SMX Penaly Clarification updated language #38337wordingwordingSMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fine; level 2 and 4 may carry $500 fine. 2025-05-01 SM Clarify Tire Marking Regs #38005wordingwordingSM cars limited to one set of Hoosier SM 7.5 P205/50/ZR17 per Super Tour event weekend for dry sessions. 2025-05-01 STL E&O: SMX Allowance in STL #37945wordingunclearSTL Mazda MX5 Challenge minimum weight now references GCR 9.1.7.1 instead of 2500 lbs; spec components removed, only alternative tires allowed.
	Atlanta Region SCCA Hoosier Super Tour @ Michelin Raceway Road Atlanta ST25MAR072025-03-07	1:36.988Mike Taylor · fastest of 13 · top 5 within 2.0s+0.632s (+0.66%)	1:37.207Mike Taylor · fastest of 11 · top 5 within 1.3s+0.354s (+0.37%)	120.1Derek Ketchie+1.7 mph (+1.5%)						1:42.848Sean Noonan · fastest of 35 · top 5 within 0.2s+0.228s (+0.22%)	1:42.625Sean Noonan · fastest of 33 · top 5 within 0.6s-0.370s (-0.36%)	107.0Sean Noonan+1.8 mph (+1.7%)	+5.418squal +5.860s	105.6%qual 106.0%
6 rule changes (STL: 1, SM: 5)6 wording · SMX allows OE instrument cluster relocation for aftermarket dash mounting, with wiring re-routed only; alternate gauges now permitted. · STL/STU: 90-05 Mazda Miata alternate front wheel hubs moved from General to specific part approval. · SMX Spec MX-5 camera requirement wording changed; non-functioning recorder now grounds for penalty or disqualification. · SMX Spec MX-5 must run latest AIM Data Logger Spec MX-5 ECU Protocol; wording clarification for technical compliance. · SMX Mazda Miata OE versus OEM definitions clarified in GCR Section 9.1.7.1. · SM and SMX shifter bushing rules clarified: alternate bushing at shift lever bottom now allowed.showhide 2024-12-01 SM E&O SMX Regs 9.1.7.1.D.5.u-.w #37070wordingwordingSMX allows OE instrument cluster relocation for aftermarket dash mounting, with wiring re-routed only; alternate gauges now permitted. 2024-12-01 STL Request to Remove Miata Hubs from General category #37138wordingwordingSTL/STU: 90-05 Mazda Miata alternate front wheel hubs moved from General to specific part approval. 2024-09-01 SM SMX Camera Rule Correction #36496wordingwordingSMX Spec MX-5 camera requirement wording changed; non-functioning recorder now grounds for penalty or disqualification. 2024-09-01 SM Committee) AIM ECU Protocol #36556wordingwordingSMX Spec MX-5 must run latest AIM Data Logger Spec MX-5 ECU Protocol; wording clarification for technical compliance. 2024-09-01 SM Committee) OE versus OEM Definitons #36608wordingwordingSMX Mazda Miata OE versus OEM definitions clarified in GCR Section 9.1.7.1. 2024-09-01 SM Committee) Shifter Bushing #36611wordingwordingSM and SMX shifter bushing rules clarified: alternate bushing at shift lever bottom now allowed.
	Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta ST24MAR082024-03-08	1:36.356Danny Steyn · fastest of 15 · top 5 within 3.3s-0.113s (-0.12%)	1:36.853Danny Steyn · fastest of 17 · top 5 within 2.8s+1.641s (+1.72%)	118.3Mike Taylor-8.8 mph (-6.9%)	1:30.014Clint McMahan · fastest of 8 · top 5 within 4.6s-5.777s (-6.03%)	1:30.267Clint McMahan · fastest of 8 · top 5 within 4.8s-4.980s (-5.23%)	132.1Calvin Stewart-3.7 mph (-2.7%)	-6.586squal -6.342s	93.2%qual 93.4%	1:42.620Danny Steyn · fastest of 47 · top 5 within 0.4s+0.001s (+0.00%)	1:42.995Charles Mactutus · fastest of 46 · top 5 within 0.1s+0.442s (+0.43%)	105.2Tyler Brown-6.9 mph (-6.2%)	+6.142squal +6.264s	106.3%qual 106.5%
5 rule changes (STL: 5)2 induction · 1 engine · 2 wording · STL and STU power steering rules clarified to permit electric-assisted and hydraulic-assisted steering systems. · STL Acura/Honda B-series and Mazda MZR restrictors reduced 2mm; minimum weights down 25–75 lbs for 1900–2000cc engines. · STL Mazda 12A must keep 5th and 6th intake port actuators and valves, no longer allowed removal or disabling. · STL Mazda RX-7 12A (79-85) now allows auto-type 2 bbl with 42mm choke(s) on dual-y manifold as alternate to stock Nikki 4 bbl. · STL ITA/ITS RX7 and 1985+ ITA/ITS/ITB/ITC vehicles clarified to conform to section 9.1.4.2 tire specifications.showhide 2024-02-01 STL ST Electric-Assisted Steering Systems #35066wordingwordingSTL and STU power steering rules clarified to permit electric-assisted and hydraulic-assisted steering systems. 2024-02-01 STL BOP Adjustments #35112inductionfasterSTL Acura/Honda B-series and Mazda MZR restrictors reduced 2mm; minimum weights down 25–75 lbs for 1900–2000cc engines. 2024-02-01 STL Mazda 12A #35320engineslowerSTL Mazda 12A must keep 5th and 6th intake port actuators and valves, no longer allowed removal or disabling. 2024-01-01 STL Alternate Carburetor Request for 79-85 RX7 12a #35181inductionunclearSTL Mazda RX-7 12A (79-85) now allows auto-type 2 bbl with 42mm choke(s) on dual-y manifold as alternate to stock Nikki 4 bbl. 2023-06-01 STL Clarify STL table B - IT spec notes on Tires #34187wordingwordingSTL ITA/ITS RX7 and 1985+ ITA/ITS/ITB/ITC vehicles clarified to conform to section 9.1.4.2 tire specifications.
	Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta ST23MAR102023-03-10	1:36.469Danny Steyn · fastest of 16 · top 5 within 3.9s+0.493s (+0.51%)	1:35.212Danny Steyn · fastest of 17 · top 5 within 3.8s-0.267s (-0.28%)	127.1Mike Taylor+0.7 mph (+0.6%)	1:35.791George Bugg · fastest of 5 · top 5 within 8.8s	1:35.247H Cory McLeod · fastest of 5 · top 5 within 9.3s	135.8Jack Walbran	+0.035squal -0.678s	100.0%qual 99.3%	1:42.619Charles Mactutus · fastest of 48 · top 5 within 0.7s-0.195s (-0.19%)	1:42.553Charles Mactutus · fastest of 47 · top 5 within 0.4s+0.689s (+0.68%)	112.2Jonathan Neudorf-1.3 mph (-1.2%)	+7.341squal +6.150s	107.7%qual 106.4%
7 rule changes (STL: 1, SM: 2, F5: 4)1 induction · 1 weight · 5 wording · SM Mazda MX-5 Miata 01-05 weight increases to 2450 lbs, or 2465 with alternate bore. · STL Spec MX5 clutch, wheels, and tyres specified: ACT 0000-02-5004-G6, 17x8 wheels, Toyo RR and RA1 235-40-17. · F500 Rotax 493 and 593 intake boots: removed Moto Tassinari V3124-873B-2 option for non-HO, corrected BPP part numbers. · F500 Rotax engines now permitted to use Ingi Tech Sparker ignition DCP-CDI-P2 as alternate ECU. · F500 Honda CBR600RR, Suzuki GSXR600, Yamaha R6 stepped diameter exhaust headers prohibited. · F500 adds optional intake resonator removal for 593 engines with mandatory plugging; clarifies approved 38mm intake boots; permits stock oil injection pump removal. · SM Majors must run authorized Penske shock and mount; Regional competitors' requirement eligibility clarified.showhide 2023-01-01 SM BOP for NB1 and NB2 #32309weightslowerSM Mazda MX-5 Miata 01-05 weight increases to 2450 lbs, or 2465 with alternate bore. 2023-01-01 STL Spec MX5 in STL #33473wordingwordingSTL Spec MX5 clutch, wheels, and tyres specified: ACT 0000-02-5004-G6, 17x8 wheels, Toyo RR and RA1 235-40-17. 2022-09-01 F5 Intake Boots Correction #33028inductionslowerF500 Rotax 493 and 593 intake boots: removed Moto Tassinari V3124-873B-2 option for non-HO, corrected BPP part numbers. 2022-08-01 F5 Ensure availability of ECU for Rotax engines #32695wordingwordingF500 Rotax engines now permitted to use Ingi Tech Sparker ignition DCP-CDI-P2 as alternate ECU. 2022-07-01 F5 Clarify stepped exhaust header references #32743wordingwordingF500 Honda CBR600RR, Suzuki GSXR600, Yamaha R6 stepped diameter exhaust headers prohibited. 2022-06-01 F5 593 carb boot availability and oil pump clarification #32527wordingwordingF500 adds optional intake resonator removal for 593 engines with mandatory plugging; clarifies approved 38mm intake boots; permits stock oil injection pump removal. 2022-04-01 SM Update GCR Section 9.1.7.3.A.1. #32217wordingwordingSM Majors must run authorized Penske shock and mount; Regional competitors' requirement eligibility clarified.
	Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta ST22MAR122022-03-12	1:35.976Danny Steyn · fastest of 18 · top 5 within 2.9s-0.449s (-0.47%)	1:35.479Danny Steyn · fastest of 18 · top 5 within 3.2s-1.326s (-1.37%)	126.3Trever Degioanni+2.5 mph (+2.1%)						1:42.814Connor Zilisch · fastest of 60 · top 5 within 0.3s+1.016s (+1.00%)	1:41.864Travis Wiley · fastest of 60 · top 5 within 0.7s-0.700s (-0.68%)	113.5Junior Brock-0.1 mph (-0.1%)	+6.385squal +6.838s	106.7%qual 107.1%	1:30.355Wiley McMahan · fastest of 11 · top 5 within 5.0s+0.336s (+0.37%)	1:31.333Wiley McMahan · fastest of 11 · top 5 within 5.4s+0.934s (+1.03%)	138.2Wiley McMahan-3.4 mph (-2.4%)	-4.146squal -5.621s	95.7%qual 94.1%
17 rule changes (STL: 11, SM: 1, F5: 5)2 cars added · 2 induction · 1 engine · 1 tyres & wheels · 1 weight · 9 wording · 1 other · F500 must install AIM part #X47KPFSOLO2R0 data box mount for Majors Races and Runoffs. · STU normally aspirated engines: minimum weights reduced up to 310 lbs; single throttle body weight reduction removed. · STL and STU Improved Touring vehicles must conform to 9.1.4 Tires & Wheels requirements. · F5 cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors Races and Runoffs. · STL and STU piston engines clarified: intake manifold and cylinder head porting remains free. · STL Mazda Renesis flat plate restrictor increases from 55mm to 60mm. · STL Mazda RX-7 12A 79-85 clarifies carburetor, emissions, and water jacket modification rules. · STL Spec MX-5 removes redundant specification line; no performance change. · F5 clarifies assisted shifting: mechanical only, no solenoids or air-shifters; throttle/ignition devices allowed if driver controls initiation. · F5 single-seat open-wheel cars: rigid suspension terminology changed to limited suspension. · F500 Rotax 593 HO engine added at 875 lbs with MA0242SP1020A or MA0242SP1063A restrictor. · STL Volkswagen 2.0L TFSI 1984cc classified with turbocharger removal required, meeting all other STL specs. · STL Pontiac Solstice/Saturn Sky allowed 4" ride height. · STL Mazda B5 DOHC added to classification with standard STL regulations. · STL Honda B16A JDM restrictor reduced from 54mm to 53mm. · SM adds procedures for testing obsolete part replacements and BOP updates in sanctioned events with CRB approval. · ST oil coolers and filters now explicitly allowed to be added or substituted; wording clarifies existing permissions.showhide 2022-03-01 F5 E&O class name #32194wordingwordingF500 must install AIM part #X47KPFSOLO2R0 data box mount for Majors Races and Runoffs. 2022-03-01 STL Single TB Weight Modifiers #31449weightfasterSTU normally aspirated engines: minimum weights reduced up to 310 lbs; single throttle body weight reduction removed. 2022-03-01 STL Improved Touring Tires #32063tyres & wheelstyres & wheelsSTL and STU Improved Touring vehicles must conform to 9.1.4 Tires & Wheels requirements. 2022-01-01 F5 Data Box Mounting Plate #31638otherotherF5 cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors Races and Runoffs. 2022-01-01 STL Throttling Device Clarification #31323wordingwordingSTL and STU piston engines clarified: intake manifold and cylinder head porting remains free. 2022-01-01 STL Mazda Renesis Restriction #31467inductionfasterSTL Mazda Renesis flat plate restrictor increases from 55mm to 60mm. 2022-01-01 STL Clarification of 79-85 RX7 Spec line #31621wordingwordingSTL Mazda RX-7 12A 79-85 clarifies carburetor, emissions, and water jacket modification rules. 2021-09-01 STL Request to clean up Spec MX-5 Redundancy #31069wordingwordingSTL Spec MX-5 removes redundant specification line; no performance change. 2021-08-01 F5 Clarify allowable assisted shifting systems #30871wordingwordingF5 clarifies assisted shifting: mechanical only, no solenoids or air-shifters; throttle/ignition devices allowed if driver controls initiation. 2021-08-01 F5 Request to correct terminology #30976wordingwordingF5 single-seat open-wheel cars: rigid suspension terminology changed to limited suspension. 2021-06-01 F5 Request to Allow Rotax 593 HO Engine #30712cars addedcars addedF500 Rotax 593 HO engine added at 875 lbs with MA0242SP1020A or MA0242SP1063A restrictor. 2021-06-01 STL VW Engine Request #30625engineslowerSTL Volkswagen 2.0L TFSI 1984cc classified with turbocharger removal required, meeting all other STL specs. 2021-05-01 STL Solstice Ride Height #30183wordingwordingSTL Pontiac Solstice/Saturn Sky allowed 4" ride height. 2021-05-01 STL Request Mazda B5 DOHC #30420cars addedcars addedSTL Mazda B5 DOHC added to classification with standard STL regulations. 2021-05-01 STL Honda B16A (JDM) Restrictor change #30531inductionslowerSTL Honda B16A JDM restrictor reduced from 54mm to 53mm. 2021-04-01 SM Updates - Obsolete Parts & BOP Parts #30438wordingwordingSM adds procedures for testing obsolete part replacements and BOP updates in sanctioned events with CRB approval. 2021-04-01 STL ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wordingwordingST oil coolers and filters now explicitly allowed to be added or substituted; wording clarifies existing permissions.
	Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta ST21MAR192021-03-19	1:36.425Danny Steyn · fastest of 24 · top 5 within 3.0s	1:36.805Danny Steyn · fastest of 22 · top 5 within 3.1s	123.8Eric Diaz						1:41.798Danny Steyn · fastest of 68 · top 5 within 0.7s	1:42.564Preston Pardus · fastest of 67 · top 5 within 0.2s	113.6Marc Cefalo	+5.759squal +5.373s	105.9%qual 105.6%	1:30.019Ryan Mayfield · fastest of 11 · top 5 within 7.0s	1:30.399Calvin Stewart · fastest of 11 · top 5 within 5.2s	141.6Ryan Mayfield	-6.406squal -6.406s	93.4%qual 93.4%
44 earlier rule changes on record, in force before Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta (from 2019)9 induction · 4 cars added · 4 weight · 2 aero · 2 engine · 1 suspension & brakes · 21 wording · 1 other · STL GM Ecotec engines now permit any combination within the family, must use 55mm flat plate restrictor. · 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. · STL rear wing trailing edge, including end plates and gurney flap, maximum rearward mounting clarified to center of rearmost bodywork. · STL allows OEM gear sets from same manufacturer transmissions with input shaft modifications for fitment. · STL RWD strut suspension weight penalty cut to 0.5%, other RWD cut to 2.5%. · STL Honda F20C loses 2% weight penalty, minimum weight reduced by approximately 35 lbs. · STL Honda B16/B17/B18C1 restrictor tightened to 53mm; B18C variants and Mazda MZR to 52mm. · ST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch. · F500 Suzuki GSXR600 engine years extended from 2003-2013 to 2003-2019. · SM aftermarket radiators must mount in original location, maintain core plane, require no body modifications, block openings, keep one OEM fan in stock location; 1990-1997 cars may install upper radiator seal NA75-50-OK7A. · SM rear brake calipers may use single bracket under upper retaining bolt to prevent pin failure. · 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. · F5 request to adjust external jetting devices cockpit control denied by Club Racing Board. · Unable to summarize: letter references response in separate Fastrack document not provided. · GT3 and STU add Borg-Warner EFR6258 to approved turbocharger list. · STL adds 2016-2019 Mazda MX-5 Global Cup at 2000cc, 2450-2550 lbs minimum weight. · STL Mazda MX-5 Club Model 06-15 allows Mazda header part number 0000-06-5407-NC. · STL Honda/Acura B18 non-C gets 54mm restrictor; B18C variants drop B18C1, get 53mm restrictor. · STL Honda B18 restrictor reduced from 54mm to 53mm flat plate; B18C1 added with 54mm restrictor. · STU GM Ecotech LNF now allowed with turbo removed or with LE5 head and intake manifold, meeting STL specs. · STL Mazda MZR restrictor reduced from 54 mm to 53 mm. · STL Mazda MZR restrictor reduced from 55 mm to 53 mm. · STL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL. · F500 Honda CBR600RR, Suzuki GSXR600, Yamaha R6 restrictor reduced from 29mm to 28mm Flat Plate Intake. · Mazda Spec MX-5 Challenge classified in STL with 2000cc displacement and 2500 lbs minimum weight. · F500 Honda CBR600RR, Suzuki GSXR600, and Yamaha R6 (03-13) minimum weight increases from 875 to 900 lbs. · STU alternate intake manifolds now allowed case-by-case instead of prohibited. · STL Acura/Honda B18 except C engine restrictor increases from 53mm to 54mm flat plate. · STL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld. · SM fuel pump and filter must be Mazda or OEM Equivalent part. · STL adds VW 1.8L R4 20VT 1781cc, 1 minimum weight, turbo removed permitted. · STL Mazda Renesis minimum weight reduced from 2800 to 2700 lbs. · STL Mazda MX-5 Cup brake pad compound changed to open. · STL adds Acura/Honda B18C1 GSR with 54mm flat plate restrictor and port matching limited to 1 inch. · STL Mazda 12 and 13B now permit port matching; previous ban removed. · SM 1999-2000 model year cars may use replacement Mazda ECU and injector harnesses, unmodified. · SM electrical rules reorganized and clarified; alternator external regulation now prohibited except via OEM ECU/kill switch. · SM removes tire tread protrusion beyond fender opening requirement from GCR 9.1.7.C.5. · STL B18C Type R variants get 54mm flat plate restrictor; B17 also gets 54mm restrictor. · STL Mazda Miata removes maximum displacement limit and adjusts minimum weight.showhide 2021-03-01 STL GM Ecotec engines in STL #30247wordingwordingSTL GM Ecotec engines now permit any combination within the family, must use 55mm flat plate restrictor. 2021-03-01 STL Super Touring Alternate Miata Hubs #30345wordingwordingSTL/STU 90-05 Mazda Miata gains approval for Mazda Motorsports Development alternate front wheel hubs. 2021-02-01 STL Brake Component Relocation #29990wordingwordingST cars may relocate ABS actuation hardware and wiring anywhere in engine compartment. 2021-02-01 STL Super Touring Wing Clarification #30111aeroaeroSTL rear wing trailing edge, including end plates and gurney flap, maximum rearward mounting clarified to center of rearmost bodywork. 2021-02-01 STL Transmission Options #30118wordingwordingSTL allows OEM gear sets from same manufacturer transmissions with input shaft modifications for fitment. 2021-01-01 STL Request for FWD and RWD Parity #29728weightfasterSTL RWD strut suspension weight penalty cut to 0.5%, other RWD cut to 2.5%. 2021-01-01 STL Request to Remove Honda F20C 2% Weight Penalty #29815weightfasterSTL Honda F20C loses 2% weight penalty, minimum weight reduced by approximately 35 lbs. 2021-01-01 STL Request for FWD and RWD Parity #30023inductionslowerSTL Honda B16/B17/B18C1 restrictor tightened to 53mm; B18C variants and Mazda MZR to 52mm. 2020-12-01 STL Request clarification on wing measurement #29640aeroaeroST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch. 2020-10-01 F5 Request to Update Suzuki Engine Years for F500 #29453wordingwordingF500 Suzuki GSXR600 engine years extended from 2003-2013 to 2003-2019. 2020-10-01 SM Radiator E&O Clarifications #29294wordingwordingSM aftermarket radiators must mount in original location, maintain core plane, require no body modifications, block openings, keep one OEM fan in stock location; 1990-1997 cars may install upper radiator seal NA75-50-OK7A. 2020-08-01 SM Modifications to prevent failures of Rear Brake Caliper Pin #28953suspension & brakessuspension & brakesSM rear brake calipers may use single bracket under upper retaining bolt to prevent pin failure. 2020-08-01 STL Minimum Weight Determination #27695wordingwordingSTL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis adjustments. 2020-08-01 STL ST Gurney flap Wicker clarification #29012wordingwordingSTL and STU rear wing rules clarify that wicker is a Gurney flap; no performance change. 2020-07-01 F5 Request for Cockpit Adjustment of External Jetting Devices #28359wordingwordingF5 request to adjust external jetting devices cockpit control denied by Club Racing Board. 2020-07-01 F5 Two Stroke Motors (reply to #28359 WDYT) #28816engine 2020-07-01 F5 Re letter requesting driver adjustable carb mixture #28840other 2020-07-01 F5 #28359 WDYT Request for Cockpit Adjustment #28875wordingunclearUnable to summarize: letter references response in separate Fastrack document not provided. 2020-07-01 STL Request for Addition to GT3 Approved Turbo List #27576wordingwordingGT3 and STU add Borg-Warner EFR6258 to approved turbocharger list. 2020-06-01 STL Request to add 2016-2019 GMX-5 Spec line #28604cars addedcars addedSTL adds 2016-2019 Mazda MX-5 Global Cup at 2000cc, 2450-2550 lbs minimum weight. 2020-06-01 STL Request to update PN for MX-5 #28622wordingunclearSTL Mazda MX-5 Club Model 06-15 allows Mazda header part number 0000-06-5407-NC. 2020-06-01 STL Correction - Clarification Honda/Acura B18B engine Letter # 26209 #28873inductionunclearSTL Honda/Acura B18 non-C gets 54mm restrictor; B18C variants drop B18C1, get 53mm restrictor. 2020-05-01 STL STL Honda B18 restrictor changes #28794inductionfasterSTL Honda B18 restrictor reduced from 54mm to 53mm flat plate; B18C1 added with 54mm restrictor. 2020-04-01 STL 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. 2020-04-01 STL Acura/Honda B18C engine chart. Reduce the current 54 mm flat plat #28663inductionslowerSTL Mazda MZR restrictor reduced from 54 mm to 53 mm. 2020-04-01 STL Mazda MZR engine chart. Reduce the current 55 mm flat plate to 53 #28664inductionslowerSTL Mazda MZR restrictor reduced from 55 mm to 53 mm. 2020-03-01 STL Request to add wheel part numbers #28342wordingwordingSTL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL. 2020-01-01 F5 Change 600cc restrictor size #27883inductionslowerF500 Honda CBR600RR, Suzuki GSXR600, Yamaha R6 restrictor reduced from 29mm to 28mm Flat Plate Intake. 2019-10-01 STL Request to Classify Spec MX-5 Challenge in STL #27399cars addedcars addedMazda Spec MX-5 Challenge classified in STL with 2000cc displacement and 2500 lbs minimum weight. 2019-08-31 F5 Request for Weight Increase for Motorcycle Powered Cars #27214weight +25 lbsslowerF500 Honda CBR600RR, Suzuki GSXR600, and Yamaha R6 (03-13) minimum weight increases from 875 to 900 lbs. 2019-07-01 STL Request clarification for manifold and throttle in STU #27004inductionfasterSTU alternate intake manifolds now allowed case-by-case instead of prohibited. 2019-05-31 STL Request Restrictor Plate correction #26779inductionfasterSTL Acura/Honda B18 except C engine restrictor increases from 53mm to 54mm flat plate. 2019-05-01 STL Request Ride Height Clarification #26597wordingwordingSTL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld. 2019-03-01 SM Request to allow aftermarket fuel filters. #26370wordingwordingSM fuel pump and filter must be Mazda or OEM Equivalent part. 2019-03-01 STL Request to Allow VW 1.8L Engine #25614cars addedcars addedSTL adds VW 1.8L R4 20VT 1781cc, 1 minimum weight, turbo removed permitted. 2019-03-01 STL Request to reduce weight of RX8 with Renesis rotary #25781weight -100 lbsfasterSTL Mazda Renesis minimum weight reduced from 2800 to 2700 lbs. 2019-03-01 STL Request for Open Brake Pads On Mazda MX-5 Cup NC #25821wordingwordingSTL Mazda MX-5 Cup brake pad compound changed to open. 2019-03-01 STL Request to clarify B18C1 GSR Honda B motor table #26209cars addedcars addedSTL adds Acura/Honda B18C1 GSR with 54mm flat plate restrictor and port matching limited to 1 inch. 2019-03-01 STL Port Matching #26415wordingfasterSTL Mazda 12 and 13B now permit port matching; previous ban removed. 2019-02-01 SM Request 99-00 replacement Wire harnesses #25602wordingwordingSM 1999-2000 model year cars may use replacement Mazda ECU and injector harnesses, unmodified. 2019-02-01 SM Organize and Clarify 9.1.7.C.1.o. #25913wordingwordingSM electrical rules reorganized and clarified; alternator external regulation now prohibited except via OEM ECU/kill switch. 2019-02-01 SM Strike Tire Tread Language #26123wordingwordingSM removes tire tread protrusion beyond fender opening requirement from GCR 9.1.7.C.5. 2019-01-01 STL Request to equalize FPR Reduction on all B-Series Vtec Engines #24746inductionslowerSTL B18C Type R variants get 54mm flat plate restrictor; B17 also gets 54mm restrictor. 2019-01-01 STL Request E&O for Mazda Miata Spec Line #25955wordingunclearSTL Mazda Miata removes maximum displacement limit and adjusts minimum weight.

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 STL" is the class's best as a share of STL'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 STL'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.