BoP Lab / Michelin Raceway Road Atlanta

STL vs F6 vs SM vs SRF3 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 · SRF3 1:33.550 Peyton Long, Atlanta Region SCCA Hoosier Super Tour @ Michelin Raceway Road Atlanta qualifying

Lap times% of STL

STLF6SMSRF3solid race · dashed qualifying · slower is lower

STLF6SMSRF3solid 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					SRF3
	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%	1:33.550Peyton Long · fastest of 51 · top 5 within 0.3s-0.053s (-0.06%)	1:34.016Robeson Clay Russell · fastest of 50 · top 5 within 0.4s+0.231s (+0.25%)	129.9Grant Vogel+7.5 mph (+6.2%)	-2.809squal -3.450s	97.1%qual 96.4%
11 rule changes (STL: 3, SM: 3, SRF3: 5)2 weight · 8 wording · 1 other · SRF3 spark plugs restricted to NGK LTR7IX-11 P/N G301041 only, washers and sealing rings prohibited. · STL minimum weights increase across all classes, 1300 cc gains 195 lbs to 1950, up to 1850 cc at 2500. · SRF3 adds HD Oil Cooler P/N G1148500 as alternative to standard cooler P/N G480503. · SRF3 brakes restructured: Hawk Blue 801993 pads, Wilwood 800065 rotors only; adds Girling 880358, Wilwood 880357, Tilton 880360 master cylinders. · 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. · SRF drivers with disabilities may modify seat and controls for safety and comfort with approval and logbook notation. · SRF SADEV-SRF3 6-speed sequential transmission gear ratios wording clarified, effective 2025-04-01.showhide 2026-03-01 SRF3 SRF3 Spark Plugs #39899wordingwordingSRF3 spark plugs restricted to NGK LTR7IX-11 P/N G301041 only, washers and sealing rings prohibited. 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. 2025-10-01 SRF3 Add HD Oil Cooler #38979otherotherSRF3 adds HD Oil Cooler P/N G1148500 as alternative to standard cooler P/N G480503. 2025-09-01 SRF3 SRF Rule Updates #38853wordingwordingSRF3 brakes restructured: Hawk Blue 801993 pads, Wilwood 800065 rotors only; adds Girling 880358, Wilwood 880357, Tilton 880360 master cylinders. 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. 2025-04-01 SRF3 Driver Safety & Comfort #37966wordingwordingSRF drivers with disabilities may modify seat and controls for safety and comfort with approval and logbook notation. 2025-04-01 SRF3 Update SADEV transmission specs #37992wordingwordingSRF SADEV-SRF3 6-speed sequential transmission gear ratios wording clarified, effective 2025-04-01.
	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%	1:33.603Peyton Long · fastest of 40 · top 5 within 0.5s-0.354s (-0.38%)	1:33.785Richard Baldwin · fastest of 40 · top 5 within 0.1s-0.388s (-0.41%)	122.4Arvid Albanese+0.2 mph (+0.1%)	-3.422squal -3.385s	96.5%qual 96.5%
12 rule changes (STL: 1, SM: 5, SRF3: 6)1 suspension & brakes · 1 tyres & wheels · 1 weight · 9 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. · SRF3 air filter rule removes K&N RC-9160 option, leaving only P/N WM301020 allowed. · SRF brake rotor minimum thickness increases from 12.20mm to 13.25mm, Wilwood vented rotor P/N 800065. · SRF3 Hoosier logo placement changes from four decals to three decals in different locations. · 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. · SRF Hoosier decal requirement reduced from four decals in specific locations to three decals with simpler placement rules. · SRF wet tires: P185/60R13 H20/W2 option removed; P185/65R13 W2 front now required with P205/60R13 W2 rear. · SRF3 alternator pulley minimum weight reduced from 12 oz to 11 oz.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. 2024-10-01 SRF3 Update SRF3 Air Filter Rule #36681wordingunclearSRF3 air filter rule removes K&N RC-9160 option, leaving only P/N WM301020 allowed. 2024-10-01 SRF3 Update SRF Brake Rotor Thickness #36687suspension & brakesslowerSRF brake rotor minimum thickness increases from 12.20mm to 13.25mm, Wilwood vented rotor P/N 800065. 2024-10-01 SRF3 Hoosier Tire Decal Placement #36739wordingwordingSRF3 Hoosier logo placement changes from four decals to three decals in different locations. 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. 2024-09-01 SRF3 Update to Letter 36619 with new Hoosier Contingency Decal Info #36624wordingwordingSRF Hoosier decal requirement reduced from four decals in specific locations to three decals with simpler placement rules. 2024-08-01 SRF3 Update Rain Tire Rule and Hoosier Decal Placement #36436tyres & wheelsslowerSRF wet tires: P185/60R13 H20/W2 option removed; P185/65R13 W2 front now required with P205/60R13 W2 rear. 2024-06-01 SRF3 SRF3 Alternator Pulley Update In #36095weightfasterSRF3 alternator pulley minimum weight reduced from 12 oz to 11 oz.
	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%	1:33.957Grant Vogel · fastest of 40 · top 5 within 0.4s-0.238s (-0.25%)	1:34.173Thomas Weir · fastest of 43 · top 5 within 0.5s-0.312s (-0.33%)	122.2Robeson Clay Russell-6.6 mph (-5.1%)	-2.680squal -2.399s	97.2%qual 97.5%
11 rule changes (STL: 5, SRF3: 6)2 induction · 2 tyres & wheels · 1 engine · 5 wording · 1 other · 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. · SRF rain/brake light now requires Super Bright LEDs Inc. P/N PT-STRB-R24 with specific connector and rain light switch. · SRF requires Super Bright LEDs P/N PT-STRB-R24 rain/brake light with strobing capability and specific wiring. · SRF adds brake duct and pedal extension rules, rear shift cable clamp option, camber limit to 5.0°, radiator opening height 3.5" ±0.5", and P2 engine restrictor changes. · 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. · SRF radiator rule clarified: P/N 480466 replaceable with Automotive P/N 1R698, CU698 or manufacturer equivalent with documentation. · SRF Hoosier wet front tire updated to P/N 46100 P185/60R13 H20 or W2. · STL ITA/ITS RX7 and 1985+ ITA/ITS/ITB/ITC vehicles clarified to conform to section 9.1.4.2 tire specifications. · SRF Hoosier front rain tyre part number changes from 46100 to 46101 P185/65R13 W2.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 SRF3 Update SRF Rain / Brake Rule #34706wordingwordingSRF rain/brake light now requires Super Bright LEDs Inc. P/N PT-STRB-R24 with specific connector and rain light switch. 2024-01-01 SRF3 Update SRF Brake Light Rule v1 #34853wordingwordingSRF requires Super Bright LEDs P/N PT-STRB-R24 rain/brake light with strobing capability and specific wiring. 2024-01-01 SRF3 SRF / SRF3 Rule Updates #35268otherotherSRF adds brake duct and pedal extension rules, rear shift cable clamp option, camber limit to 5.0°, radiator opening height 3.5" ±0.5", and P2 engine restrictor changes. 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. 2023-10-01 SRF3 SRF Radiator Rule Update #34805wordingwordingSRF radiator rule clarified: P/N 480466 replaceable with Automotive P/N 1R698, CU698 or manufacturer equivalent with documentation. 2023-06-01 SRF3 Hoosier SRF Wet Front Tire Rule Update #34189tyres & wheelsunclearSRF Hoosier wet front tire updated to P/N 46100 P185/60R13 H20 or W2. 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. 2023-05-01 SRF3 Update SRF Front W2 Rain Tire Part Number #34118tyres & wheelstyres & wheelsSRF Hoosier front rain tyre part number changes from 46100 to 46101 P185/65R13 W2.
	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%	1:34.195Charles Russell Turner · fastest of 36 · top 5 within 0.9s+0.060s (+0.06%)	1:34.485Mark Eaton · fastest of 36 · top 5 within 0.3s+0.699s (+0.75%)	128.8Derek Schofield-2.7 mph (-2.1%)	-0.727squal -2.274s	99.2%qual 97.6%
7 rule changes (STL: 1, SM: 2, SRF3: 4)2 suspension & brakes · 1 weight · 4 wording · SRF Renault Alliance solid front rotors banned; restrictor reduced 35mm to 34mm for 2011+ Kawasaki; minimum weight increased to 1100 lbs for 2009+ stock engines. · SRF3 tail sections allowed on SRFs with GEN3 airbox shimming up to 19 mm; alternate dash panel P/N 180100 or 180101 relocated in rules. · 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. · SRF tire rule wording changed from 'Tires: must be run as delivered' to 'Tires must be run as delivered.' · SRF brake rotor minimum thickness reduced from 13.25 to 12.20mm; seal and air filter rules clarified. · SM Majors must run authorized Penske shock and mount; Regional competitors' requirement eligibility clarified.showhide 2023-03-01 SRF3 Update SRF Brake Rule #33469suspension & brakesslowerSRF Renault Alliance solid front rotors banned; restrictor reduced 35mm to 34mm for 2011+ Kawasaki; minimum weight increased to 1100 lbs for 2009+ stock engines. 2023-03-01 SRF3 Update SRF Bodywork Fitment Rule #33765wordingwordingSRF3 tail sections allowed on SRFs with GEN3 airbox shimming up to 19 mm; alternate dash panel P/N 180100 or 180101 relocated in rules. 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. 2022-06-01 SRF3 SRF Tire Rule Update #32614wordingwordingSRF tire rule wording changed from 'Tires: must be run as delivered' to 'Tires must be run as delivered.' 2022-06-01 SRF3 Brake, seal, and air filter clarifications #32670suspension & brakesfasterSRF brake rotor minimum thickness reduced from 13.25 to 12.20mm; seal and air filter rules clarified. 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%	1:34.135Charles Russell Turner · fastest of 52 · top 5 within 1.2s-0.681s (-0.72%)	1:33.786Matthew Horst · fastest of 50 · top 5 within 0.2s-0.886s (-0.94%)	131.5Peyton Long+4.2 mph (+3.3%)	-1.693squal -1.841s	98.2%qual 98.1%
17 rule changes (STL: 11, SM: 1, SRF3: 5)3 tyres & wheels · 2 cars added · 2 engine · 2 induction · 1 weight · 7 wording · 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. · 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. · SRF front wet tire changes from P185/60R13 H20 to P185/65R13 W2; SRF3 adds mandatory G301048 restrictor plate Jan. 1, 2022. · STL Spec MX-5 removes redundant specification line; no performance change. · SRF wet tyres add Hoosier P185/60R13 W2 front and P205/60R13 W2 rear as alternatives to H20. · SRF adds SADEV-SRF3 6-speed sequential option with final drive 3.20 versus OEM 5-speed 3.85. · SRF seal procedures clarified: unsealed components need CSR inspection and logbook notation instead of engine removal. · SRF3 alternator pulley restricted to P/N G902130 or G902130A, 12oz minimum weight. · 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 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 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. 2021-12-01 SRF3 Three Updates to SRF Rules #31523tyres & wheelsunclearSRF front wet tire changes from P185/60R13 H20 to P185/65R13 W2; SRF3 adds mandatory G301048 restrictor plate Jan. 1, 2022. 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 SRF3 SRF Wet Tires #30849tyres & wheelstyres & wheelsSRF wet tyres add Hoosier P185/60R13 W2 front and P205/60R13 W2 rear as alternatives to H20. 2021-08-01 SRF3 SADEV-SRF3 Transmission #30926cars addedunclearSRF adds SADEV-SRF3 6-speed sequential option with final drive 3.20 versus OEM 5-speed 3.85. 2021-08-01 SRF3 SRF Update Maintenance, Repairs and Seals #30961wordingwordingSRF seal procedures clarified: unsealed components need CSR inspection and logbook notation instead of engine removal. 2021-06-01 SRF3 SRF3 Alternator Pulley #30684engineslowerSRF3 alternator pulley restricted to P/N G902130 or G902130A, 12oz minimum weight. 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%	1:34.816Brian Schofield · fastest of 77 · top 5 within 0.5s	1:34.672Mark Snyder · fastest of 69 · top 5 within 0.2s	127.3Matthew Horst	-2.133squal -1.609s	97.8%qual 98.3%
49 earlier rule changes on record, in force before Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta (from 2019)8 induction · 4 cars added · 4 weight · 3 suspension & brakes · 2 aero · 1 engine · 1 tyres & wheels · 26 wording · SRF and SRF3 mandatory identification simplified: removed Ford Performance and Blue Oval decals, kept Hoosier logo placement. · 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. · SRF shocks, springs, bump stops sealed; rear springs 412-429 lbs/in P/N 280390 only; previous parts no longer allowed. · ST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch. · 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. · GT3 and STU add Borg-Warner EFR6258 to approved turbocharger list. · SRF3 shock absorber brand restriction removed; all shocks must be sealed by Enterprises. · 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. · SRF3 bump stop now must be SCCA P/N 280407 only, no modifications, optional, max one per shock. · SRF shock absorber bump stop clarified: only SCCA P/N 280407 allowed as delivered, maximum one per shock, effective 05/01/2020. · 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. · SRF rain and brake rule wording updated; supersedes GCR 9.3.32.B.2 effective 1/1/202 through 12/31/2024. · SRF bans tire warmers and cooling methods other than natural air convection or conduction. · SRF front nose weight minimum reduced from 35 to 32 lbs. · SRF3 reclassified as Spec Racer Ford 3 with 1.6L conversion; SRF2 becomes Regional Only Class. · Mazda Spec MX-5 Challenge classified in STL with 2000cc displacement and 2500 lbs minimum weight. · SRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102. · STU alternate intake manifolds now allowed case-by-case instead of prohibited. · SRF3 nose assembly must use approved multi-piece design; no modifications allowed except as specified. · STL Acura/Honda B18 except C engine restrictor increases from 53mm to 54mm flat plate. · SRF3 brakes now allow Hawk Blue 9012 pads P/N 801993 only; shocks simplified to Penske P/N 280396 sealed assembly only, with optional SCCA Enterprises bump rubber P/N 280407 from 05/01/2020. · 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 SRF3 Mandatory identification: #30223wordingwordingSRF and SRF3 mandatory identification simplified: removed Ford Performance and Blue Oval decals, kept Hoosier logo placement. 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 SRF3 SRF Shocks, Springs and Ride Height. #29688suspension & brakessuspension & brakesSRF shocks, springs, bump stops sealed; rear springs 412-429 lbs/in P/N 280390 only; previous parts no longer allowed. 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 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 STL Request for Addition to GT3 Approved Turbo List #27576wordingwordingGT3 and STU add Borg-Warner EFR6258 to approved turbocharger list. 2020-06-01 SRF3 SRF Shocks #28791wordingwordingSRF3 shock absorber brand restriction removed; all shocks must be sealed by Enterprises. 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 SRF3 Update Bump Stop Rule #28712suspension & brakessuspension & brakesSRF3 bump stop now must be SCCA P/N 280407 only, no modifications, optional, max one per shock. 2020-05-01 SRF3 SRF Bump Stop Correction #27019wordingwordingSRF shock absorber bump stop clarified: only SCCA P/N 280407 allowed as delivered, maximum one per shock, effective 05/01/2020. 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. 202-01-01 SRF3 SRF Rain / Brake Rule - BoD approved as follows #34958wordingwordingSRF rain and brake rule wording updated; supersedes GCR 9.3.32.B.2 effective 1/1/202 through 12/31/2024. 2019-12-01 SRF3 SRF Tire Warmer Rule #27622tyres & wheelsslowerSRF bans tire warmers and cooling methods other than natural air convection or conduction. 2019-12-01 SRF3 SRF / SRF3 Nose Weight Reduction #27706weightfasterSRF front nose weight minimum reduced from 35 to 32 lbs. 2019-12-01 SRF3 SRF / SRF3 Majors & Regional Class Updates #27723wordingwordingSRF3 reclassified as Spec Racer Ford 3 with 1.6L conversion; SRF2 becomes Regional Only Class. 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. 2019-07-01 SRF3 SRF Dash Windscreen Kit #27028wordingwordingSRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102. 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 SRF3 New SRF Sectional Nose Rule Addition #26914wordingwordingSRF3 nose assembly must use approved multi-piece design; no modifications allowed except as specified. 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 SRF3 SRF Brakes and Shock Rule Changes #26629wordingwordingSRF3 brakes now allow Hawk Blue 9012 pads P/N 801993 only; shocks simplified to Penske P/N 280396 sealed assembly only, with optional SCCA Enterprises bump rubber P/N 280407 from 05/01/2020. 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.