STU vs SM vs FE2 vs SRF3 pace at Michelin Raceway Road Atlanta
Quickest here:STU 1:32.913 Tony Ave, Atlanta Region SCCA Hoosier Super Tour @ Michelin Raceway Road Atlanta qualifying · SM 1:41.798 Danny Steyn, Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta qualifying · FE2 1:22.855 Paul Schneider, Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta race · SRF3 1:33.550 Peyton Long, Atlanta Region SCCA Hoosier Super Tour @ Michelin Raceway Road Atlanta qualifying
STUSMFE2SRF3solid race · dashed qualifying · slower is lower
STUSMFE2SRF3solid 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
Event
STU
SM
FE2
SRF3
Qual best
Race best
Trap
Qual best
Race best
Trap
vs STU
% of STU
Qual best
Race best
Trap
vs STU
% of STU
Qual best
Race best
Trap
vs STU
% of STU
Atlanta Region SCCA Hoosier Super Tour @ Michelin Raceway Road Atlanta ST26MAR062026-03-06
1:32.913Tony Ave · fastest of 13 · top 5 within 3.4s-0.131s (-0.14%)
1:34.356Johan Schwartz · fastest of 14 · top 5 within 1.7s+0.419s (+0.45%)
139.8Hugh Stewart+10.0 mph (+7.7%)
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%)
+8.255squal +9.411s
108.7%qual 110.1%
1:24.639Paul Schneider · fastest of 7 · top 5 within 2.4s+1.503s (+1.81%)
1:24.978Paul Schneider · fastest of 7 · top 5 within 2.9s+1.478s (+1.77%)
138.5Paul Schneider+4.9 mph (+3.6%)
-9.378squal -8.274s
90.1%qual 91.1%
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%)
-0.340squal +0.637s
99.6%qual 100.7%
24 rule changes (STU: 14, SM: 3, FE2: 2, SRF3: 5)5 weight · 3 tyres & wheels · 2 cars added · 1 induction · 12 wording · 1 other · SRF3 spark plugs restricted to NGK LTR7IX-11 P/N G301041 only, washers and sealing rings prohibited. · STU Mazda MZR (LF, L3, L5) adds Fab 9 Elite NC MX5 Performance Intake manifold as approved option. · STU Mazda MZR (LF, L3, L5) Turbo classified; Jack Spania Racing 70 mm intake manifold and Fab9 Tuning bottom-mount turbo kit approved. · STU 36mm restrictor allows 2830 lbs (up 10 lbs from 2820); 37mm allows 2980 lbs (down 5 lbs from 2985). · STU cars over 3150 lbs lose 275-tire option with 2% weight adder. · STU Honda K20 and K24 engines lose 2% minimum weight penalty. · STU Honda K24 engine swap weight increases by 2% effective November 1, 2025. · FE and FE2 Enterprises must use bubble tail P/N WM138014; FE2 allows only this configuration. · 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. · STU Lotus Elise SC and Exige SC weight reduced from 2450 to 2250 lbs. · STU-TCR tire width increases to 275 with weight adder raised from 100 to 150 pounds. · STL/STU Lotus weight reduced: Evora GT4 to 2700 lbs, Elise Cup R to 2250 lbs, Elise/Exige SC to 2450-2550 lbs. · STU 2.8-3.2L N/A engines now allow 245 max tire width; over 3150 lbs may run 275 with 2% weight penalty. · STU Mazda MZR may use Goodwin 61-2510 or Gato Performance 31972 intake manifold. · STU Honda JDM H23a added, 2259cc displacement, minimum weight per Chart, must meet ST engine regulations. · SMX drivers must submit data acquisition files on time or face suspension and $250 fine. · SMX penalty language clarified: level 1 and 3 infractions may carry $1,000 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. · STU wheel width rules clarified: cars ≤2,850 lbs max 8 inches, cars >2,850 lbs max 9 inches. · STU Spec Line GT3U minimum weight reduced from plus 250 to plus 225 pounds; wheel and tire options clarified with weight adjustments. · FE2 allows driver safety and comfort modifications for disabled drivers with SCCA approval, not transferable to other drivers. · 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
SRF3 SRF3 Spark Plugs #39899wordingwordingSRF3 spark plugs restricted to NGK LTR7IX-11 P/N G301041 only, washers and sealing rings prohibited.
STU Fab 9 Racing Intake Manifold in STU #39767wordingwordingSTU Mazda MZR (LF, L3, L5) adds Fab 9 Elite NC MX5 Performance Intake manifold as approved option.
STU Request for Permission on Aftermarket Turbo Kit and Intake #39529cars addedfasterSTU Mazda MZR (LF, L3, L5) Turbo classified; Jack Spania Racing 70 mm intake manifold and Fab9 Tuning bottom-mount turbo kit approved.
STU Turbo Inlet Restrictor Table #38961inductionslowerSTU 36mm restrictor allows 2830 lbs (up 10 lbs from 2820); 37mm allows 2980 lbs (down 5 lbs from 2985).
STU 275 Tire Rule #38983tyres & wheelsslowerSTU cars over 3150 lbs lose 275-tire option with 2% weight adder.
STU STU Honda Engine weight penalty #39375weightfasterSTU Honda K20 and K24 engines lose 2% minimum weight penalty.
STU Non-Homologated Engine Swaps - Specifically K24A2 w/ Honda CRZ #38746weightslowerSTU Honda K24 engine swap weight increases by 2% effective November 1, 2025.
FE2 FE & FE2 Bubble Tail #38978wordingwordingFE and FE2 Enterprises must use bubble tail P/N WM138014; FE2 allows only this configuration.
SRF3 Add HD Oil Cooler #38979otherotherSRF3 adds HD Oil Cooler P/N G1148500 as alternative to standard cooler P/N G480503.
STU Lotus Weight Reduction E&O #38919weightfasterSTU Lotus Elise SC and Exige SC weight reduced from 2450 to 2250 lbs.
STU STU-TCR Adjustments #38723tyres & wheelsslowerSTU-TCR tire width increases to 275 with weight adder raised from 100 to 150 pounds.
STU 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.
STU 2.8-3.2L N/A Engine Allowances #38007tyres & wheelsunclearSTU 2.8-3.2L N/A engines now allow 245 max tire width; over 3150 lbs may run 275 with 2% weight penalty.
STU 2006-2015 Mazda Miata Intake Manifold #38422wordingwordingSTU Mazda MZR may use Goodwin 61-2510 or Gato Performance 31972 intake manifold.
STU Requesting Approval of the JDM Honda h23a #38489cars addedcars addedSTU Honda JDM H23a added, 2259cc displacement, minimum weight per Chart, must meet ST engine regulations.
SM SMX Data Submission - Penalties #38248wordingwordingSMX drivers must submit data acquisition files on time or face suspension and $250 fine.
SM Committee) SMX Penaly Clarification updated language #38337wordingwordingSMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fine; level 2 and 4 may carry $500 fine.
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.
STU Wheel Size Inconsistency #38018wordingwordingSTU wheel width rules clarified: cars ≤2,850 lbs max 8 inches, cars >2,850 lbs max 9 inches.
STU Table C: STU-GT3U Clarification #38268weightfasterSTU Spec Line GT3U minimum weight reduced from plus 250 to plus 225 pounds; wheel and tire options clarified with weight adjustments.
FE2 Driver Safety & Comfort #37965wordingwordingFE2 allows driver safety and comfort modifications for disabled drivers with SCCA approval, not transferable to other drivers.
SRF3 Driver Safety & Comfort #37966wordingwordingSRF drivers with disabilities may modify seat and controls for safety and comfort with approval and logbook notation.
Atlanta Region SCCA Hoosier Super Tour @ Michelin Raceway Road Atlanta ST25MAR072025-03-07
1:33.044Richard Astacio · fastest of 9 · top 5 within 3.8s-4.475s (-4.59%)
1:33.937Richard Astacio · fastest of 8 · top 5 within 3.5s-3.795s (-3.88%)
129.8David Fiorelli+1.8 mph (+1.4%)
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%)
+8.688squal +9.804s
109.2%qual 110.5%
1:23.136Franklin Futrelle · fastest of 8 · top 5 within 2.1s-0.076s (-0.09%)
1:23.500Franklin Futrelle · fastest of 8 · top 5 within 1.9s-0.914s (-1.08%)
133.6Eric Wisniewski+1.7 mph (+1.3%)
-10.437squal -9.908s
88.9%qual 89.4%
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%)
-0.152squal +0.559s
99.8%qual 100.6%
22 rule changes (STU: 11, SM: 5, SRF3: 6)4 induction · 3 weight · 2 tyres & wheels · 1 cars added · 1 engine · 1 suspension & brakes · 10 wording · STU BMW N54/N55 3.0L classified at Chart +3% minimum weight; N54 twin turbo not allowed. · STU Mini Cooper S SC supercharger pulley diameter reduced from 2.285 to 2.185. · STU Honda K20C1 Turbo I4 exempted from 3% DI weight adder in Spec Lines Table A. · STU GT3U minimum weight increases 150 to 250 pounds. · STU Audi 1.8T wagon deleted; Porsche 944 1800 weight to Chart, turbo inlet restrictor removed. · STU-GT3 reclassified as STU-GT3U effective January 1, 2026. · STU GT3 TCR gains 275-width tire option with 100 lb weight penalty, but not in A compound. · 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. · STU BMW N54/N55 turbo inlet restrictors now required per GCR definition; turbo swapping prohibited. · STU Mini Cooper S SC 1900 restricts to 2.565 diameter pulley; 2100 allows 2.285 diameter pulley. · 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. · STU RWD turbo cars no longer required to reduce restrictor by 1 mm from table. · SRF3 alternator pulley minimum weight reduced from 12 oz to 11 oz.showhide
STU BMW N54/N55 Engine Allowance Follow Up #37447engineengineSTU BMW N54/N55 3.0L classified at Chart +3% minimum weight; N54 twin turbo not allowed.
STU STU Mini Cooper pulley size clarification re: letter #36980 #37717inductionfasterSTU Mini Cooper S SC supercharger pulley diameter reduced from 2.285 to 2.185.
STU Question About a Weight Modifier #37782weightfasterSTU Honda K20C1 Turbo I4 exempted from 3% DI weight adder in Spec Lines Table A.
STU Increase Minimum Weight #37919weight +100 lbsslowerSTU GT3U minimum weight increases 150 to 250 pounds.
STU Audi 1.8t Wagon STU Table B #36685cars addedfasterSTU Audi 1.8T wagon deleted; Porsche 944 1800 weight to Chart, turbo inlet restrictor removed.
STU Merger GT3 to STU #37486wordingwordingSTU-GT3 reclassified as STU-GT3U effective January 1, 2026.
STU GT3 TCR Tire allowance #37494tyres & wheelsslowerSTU GT3 TCR gains 275-width tire option with 100 lb weight penalty, but not in A compound.
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.
STU 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.
STU BMW N54/N55 Engine Allowance #37146inductionslowerSTU BMW N54/N55 turbo inlet restrictors now required per GCR definition; turbo swapping prohibited.
STU R53 15% Pulley Request #36980inductionslowerSTU Mini Cooper S SC 1900 restricts to 2.565 diameter pulley; 2100 allows 2.285 diameter pulley.
SRF3 Update SRF3 Air Filter Rule #36681wordingunclearSRF3 air filter rule removes K&N RC-9160 option, leaving only P/N WM301020 allowed.
SRF3 Hoosier Tire Decal Placement #36739wordingwordingSRF3 Hoosier logo placement changes from four decals to three decals in different locations.
SM SMX Camera Rule Correction #36496wordingwordingSMX Spec MX-5 camera requirement wording changed; non-functioning recorder now grounds for penalty or disqualification.
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.
SM Committee) OE versus OEM Definitons #36608wordingwordingSMX Mazda Miata OE versus OEM definitions clarified in GCR Section 9.1.7.1.
SM Committee) Shifter Bushing #36611wordingwordingSM and SMX shifter bushing rules clarified: alternate bushing at shift lever bottom now allowed.
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.
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.
STU RWD Turbo Disadvantage #36255inductionfasterSTU RWD turbo cars no longer required to reduce restrictor by 1 mm from table.
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
1:37.519Jorge Nazario · fastest of 7 · top 5 within 5.3s+1.809s (+1.89%)
1:37.732David Fiorelli · fastest of 5 · top 5 within 7.0s+2.651s (+2.79%)
128.0David Fiorelli-7.4 mph (-5.5%)
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%)
+5.263squal +5.101s
105.4%qual 105.2%
1:23.212Franklin Futrelle · fastest of 14 · top 5 within 2.3s+0.084s (+0.10%)
1:24.414Charles Russell Turner · fastest of 13 · top 5 within 1.5s-0.040s (-0.05%)
131.9Jason Conzo-9.2 mph (-6.5%)
-13.318squal -14.307s
86.4%qual 85.3%
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%)
-3.559squal -3.562s
96.4%qual 96.3%
11 rule changes (STU: 5, SRF3: 6)2 tyres & wheels · 1 cars added · 7 wording · 1 other · STU Mini Cooper S SC: alternate LEAP OMICRON hood scoop LEP-OMICRON3 permitted. · STU BMW S54 B32 OEM now permits dry sump oiling system. · STL and STU power steering rules clarified to permit electric-assisted and hydraulic-assisted steering systems. · 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. · SRF radiator rule clarified: P/N 480466 replaceable with Automotive P/N 1R698, CU698 or manufacturer equivalent with documentation. · Toyota GR Cup and GR86 Cup (2022-) newly classified in STU at 2700 lbs with 2387 cc engine. · SRF Hoosier wet front tire updated to P/N 46100 P185/60R13 H20 or W2. · SRF Hoosier front rain tyre part number changes from 46100 to 46101 P185/65R13 W2. · STU Mazda BP5A classified at 1839 cc maximum displacement, 2023-04-01.showhide
STU Letter #35397 addendum #35453wordingwordingSTU Mini Cooper S SC: alternate LEAP OMICRON hood scoop LEP-OMICRON3 permitted.
STU S54 Drysump #35464wordingwordingSTU BMW S54 B32 OEM now permits dry sump oiling system.
STU ST Electric-Assisted Steering Systems #35066wordingwordingSTL and STU power steering rules clarified to permit electric-assisted and hydraulic-assisted steering systems.
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.
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.
SRF3 SRF Radiator Rule Update #34805wordingwordingSRF radiator rule clarified: P/N 480466 replaceable with Automotive P/N 1R698, CU698 or manufacturer equivalent with documentation.
STU 2022 Toyota GR Cup for STU #34449cars addedcars addedToyota GR Cup and GR86 Cup (2022-) newly classified in STU at 2700 lbs with 2387 cc engine.
SRF3 Hoosier SRF Wet Front Tire Rule Update #34189tyres & wheelsunclearSRF Hoosier wet front tire updated to P/N 46100 P185/60R13 H20 or W2.
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.
STU Alternate OEM Miata Intake Manifold #33827wordingwordingSTU Mazda BP5A classified at 1839 cc maximum displacement, 2023-04-01.
Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta ST23MAR102023-03-10
1:35.710Anthony Geraci · fastest of 14 · top 5 within 3.7s+0.724s (+0.76%)
1:35.081Anthony Geraci · fastest of 14 · top 5 within 2.9s+1.000s (+1.06%)
135.4David Brand-6.2 mph (-4.4%)
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%)
+7.472squal +6.909s
107.9%qual 107.2%
1:23.128Franklin Futrelle · fastest of 15 · top 5 within 2.5s+0.032s (+0.04%)
1:24.454Charles Russell Turner · fastest of 15 · top 5 within 1.2s+1.599s (+1.93%)
141.1Eric Cruz-3.0 mph (-2.1%)
-10.627squal -12.582s
88.8%qual 86.9%
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%)
-0.596squal -1.515s
99.4%qual 98.4%
20 rule changes (STU: 14, SM: 2, SRF3: 4)5 weight · 2 cars added · 2 engine · 2 suspension & brakes · 1 aero · 1 tyres & wheels · 7 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. · STU minimum weight chart updated: 2450cc to 2595lbs, 2600cc to 2710lbs. · SM Mazda MX-5 Miata 01-05 weight increases to 2450 lbs, or 2465 with alternate bore. · 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. · 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. · 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. · 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. · SM Majors must run authorized Penske shock and mount; Regional competitors' requirement eligibility clarified. · 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.showhide
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.
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.
STU E&O STU NA Weight Chart. #33737weightfasterSTU minimum weight chart updated: 2450cc to 2595lbs, 2600cc to 2710lbs.
SM BOP for NB1 and NB2 #32309weightslowerSM Mazda MX-5 Miata 01-05 weight increases to 2450 lbs, or 2465 with alternate bore.
STU Request Mazda 13 B turbo #32668cars addedcars addedSTU 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.
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 #32713wordingwordingST redundant language removed from balance shaft and pulley modification rules.
SRF3 SRF Tire Rule Update #32614wordingwordingSRF tire rule wording changed from 'Tires: must be run as delivered' to 'Tires must be run as delivered.'
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.
STU Opposed to the Proposed STU Weight Chart #32381wordingwordingSTU 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 #32414wordingwordingSTU splitter definition clarified: must be single-plane with no vertical deviations, attached to lowest front point.
SM Update GCR Section 9.1.7.3.A.1. #32217wordingwordingSM Majors must run authorized Penske shock and mount; Regional competitors' requirement eligibility clarified.
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 addedcars addedSTU BMW S50B32 Euro classified at 3201 cc displacement, 3300 lbs minimum weight.
STU Engine Swap Origin Country #32209wordingwordingST 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.
Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta ST22MAR122022-03-12
1:34.986Johan Schwartz · fastest of 9 · top 5 within 6.2s-1.596s (-1.65%)
1:34.081Johan Schwartz · fastest of 9 · top 5 within 6.7s-2.622s (-2.71%)
141.5Johan Schwartz+5.9 mph (+4.4%)
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%)
+7.783squal +7.828s
108.3%qual 108.2%
1:23.096Paul Schneider · fastest of 13 · top 5 within 2.8s-1.268s (-1.50%)
1:22.855Paul Schneider · fastest of 13 · top 5 within 2.5s-1.101s (-1.31%)
144.1Bailey Monette+5.2 mph (+3.8%)
-11.226squal -11.890s
88.1%qual 87.5%
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%)
-0.295squal -0.851s
99.7%qual 99.1%
19 rule changes (STU: 13, SM: 1, SRF3: 5)4 engine · 3 tyres & wheels · 3 weight · 2 cars added · 1 aero · 6 wording · 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. · 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. · SRF front wet tire changes from P185/60R13 H20 to P185/65R13 W2; SRF3 adds mandatory G301048 restrictor plate Jan. 1, 2022. · 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. · 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. · SRF3 alternator pulley restricted to P/N G902130 or G902130A, 12oz minimum weight. · STU fender flare rules clarified: maximum 2 inches, must cover tire contact patch from above, cannot alter body configuration or wheel opening geometry. · SM adds procedures for testing obsolete part replacements and BOP updates in sanctioned events with CRB approval. · 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.showhide
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 & wheelstyres & wheelsSTL 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 #31916aeroaeroSTU hood vents allowed to include louvers within 200 sq. inch area.
STU Request to Add Honda K23 Spec Line #30682cars addedcars addedSTU 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 #31323wordingwordingSTL and STU piston engines clarified: intake manifold and cylinder head porting remains free.
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.
SRF3 SRF Wet Tires #30849tyres & wheelstyres & wheelsSRF wet tyres add Hoosier P185/60R13 W2 front and P205/60R13 W2 rear as alternatives to H20.
SRF3 SADEV-SRF3 Transmission #30926cars addedunclearSRF adds SADEV-SRF3 6-speed sequential option with final drive 3.20 versus OEM 5-speed 3.85.
SRF3 SRF Update Maintenance, Repairs and Seals #30961wordingwordingSRF seal procedures clarified: unsealed components need CSR inspection and logbook notation instead of engine removal.
STU STU Fender flares #30696wordingwordingSTU 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.
SRF3 SRF3 Alternator Pulley #30684engineslowerSRF3 alternator pulley restricted to P/N G902130 or G902130A, 12oz minimum weight.
STU Request for Fender Flare Clarification #30375wordingwordingSTU fender flare rules clarified: maximum 2 inches, must cover tire contact patch from above, cannot alter body configuration or wheel opening geometry.
SM Updates - Obsolete Parts & BOP Parts #30438wordingwordingSM adds procedures for testing obsolete part replacements and BOP updates in sanctioned events with CRB approval.
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 #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
1:36.582David Brand · fastest of 10 · top 5 within 6.9s
1:36.703David Brand · fastest of 8 · top 5 within 5.5s
135.6David Brand
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
+5.861squal +5.216s
106.1%qual 105.4%
1:24.364Bailey Monette · fastest of 18 · top 5 within 1.3s
1:23.956Bailey Monette · fastest of 18 · top 5 within 0.8s
138.9T Vanacore
-12.747squal -12.218s
86.8%qual 87.3%
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
-2.031squal -1.766s
97.9%qual 98.2%
66 earlier rule changes on record, in force before Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta (from 2019)7 induction · 6 cars added · 5 engine · 4 weight · 3 aero · 3 suspension & brakes · 2 tyres & wheels · 36 wording · SRF and SRF3 mandatory identification simplified: removed Ford Performance and Blue Oval decals, kept Hoosier logo placement. · 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. · STU Mazda 13B Street Port classified at 2400 lbs minimum weight, replacing peripheral and bridge port variants. · 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. · FE2 oil cooler wording clarified: optional air-to-oil cooler allowed, Setrab 50-625-7612 or equivalent max 13 inches wide by 6.5 inches high. · STU fender flare rules reworded: up to 2" per corner allowed with 1% weight penalty total. · 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. · 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. · SRF3 shock absorber brand restriction removed; all shocks must be sealed by Enterprises. · STU Mazda 13B Bridge Port and Street Port engines added with 2550 and 2250 lbs minimum weights respectively. · 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. · 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. · SRF rain and brake rule wording updated; supersedes GCR 9.3.32.B.2 effective 1/1/202 through 12/31/2024. · FE and FE2 minimum weight increased to 1270 lbs including driver; spring options and tire warmer ban added. · 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. · STU cars with manual OEM throttle bodies may convert to OEM electronic throttle body of same inner diameter. · STU wing assembly wording corrected: no part higher than roof height. · SRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102. · STU Nissan SR20DET removes -2mm penalty in Table B. · 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. · 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. · 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. · 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. · SM fuel pump and filter must be Mazda or OEM Equivalent part. · 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. · 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. · STU Honda K20C1 Turbo I4 1996cc added at 3025 lbs minimum weight with 36mm TIR.showhide
SRF3 Mandatory identification: #30223wordingwordingSRF and SRF3 mandatory identification simplified: removed Ford Performance and Blue Oval decals, kept Hoosier logo placement.
STU Super Touring Alternate Miata Hubs #30345wordingwordingSTL/STU 90-05 Mazda Miata gains approval for Mazda Motorsports Development alternate front wheel hubs.
STU Brake Component Relocation #29990wordingwordingST cars may relocate ABS actuation hardware and wiring anywhere in engine compartment.
STU Porsche PDK #30081wordingwordingSTU 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 #30087wordingwordingSTU driveshaft and half-shaft materials change from OEM-type to steel or aluminum.
STU 13B Rules Adjustment #29333cars addedslowerSTU Mazda 13B Street Port classified at 2400 lbs minimum weight, replacing peripheral and bridge port variants.
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.
STU Request clarification on wing measurement #29640aeroaeroST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch.
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.
FE2 FE/FE2 Oil Cooler #29293wordingwordingFE2 oil cooler wording clarified: optional air-to-oil cooler allowed, Setrab 50-625-7612 or equivalent max 13 inches wide by 6.5 inches high.
STU Request for Advanced Aero Rule Wording Clarification. #29124wordingwordingSTU fender flare rules reworded: up to 2" per corner allowed with 1% weight penalty total.
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.
STU Minimum Weight Determination #27695wordingwordingSTL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis adjustments.
STU ST Gurney flap Wicker clarification #29012wordingwordingSTL and STU rear wing rules clarify that wicker is a Gurney flap; no performance change.
STU Request for Alternate Intake Manifold #26514wordingwordingSTU request for alternate intake manifold denied; no rule change issued.
STU Request for Addition to GT3 Approved Turbo List #27576wordingwordingGT3 and STU add Borg-Warner EFR6258 to approved turbocharger list.
STU Request BoP for my Car #29004wordingwordingSTU large displacement turbo engines limited by GCR turbo list; non-turbo trim suggested as more competitive.
STU Sequential Shifters in STU #29031wordingwordingSTU sequential shifters referred to Board of Directors for approval; no change implemented yet.
SRF3 SRF Shocks #28791wordingwordingSRF3 shock absorber brand restriction removed; all shocks must be sealed by Enterprises.
STU Rotary Help #27833cars addedcars addedSTU Mazda 13B Bridge Port and Street Port engines added with 2550 and 2250 lbs minimum weights respectively.
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.
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.
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 #28032wordingwordingSTU turbocharged engines now use base weight instead of minimum weight, with 3% DI increase applied to base weight.
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.
FE2 FE / FE2 Update Rules #27624weightslowerFE and FE2 minimum weight increased to 1270 lbs including driver; spring options and tire warmer ban added.
SRF3 SRF Tire Warmer Rule #27622tyres & wheelsslowerSRF bans tire warmers and cooling methods other than natural air convection or conduction.
SRF3 SRF / SRF3 Nose Weight Reduction #27706weightfasterSRF front nose weight minimum reduced from 35 to 32 lbs.
SRF3 SRF / SRF3 Majors & Regional Class Updates #27723wordingwordingSRF3 reclassified as Spec Racer Ford 3 with 1.6L conversion; SRF2 becomes Regional Only Class.
STU Request for an electronic throttle body #27342wordingwordingSTU cars with manual OEM throttle bodies may convert to OEM electronic throttle body of same inner diameter.
STU Request to correct E&O advanced aerodynamics #27290wordingwordingSTU wing assembly wording corrected: no part higher than roof height.
SRF3 SRF Dash Windscreen Kit #27028wordingwordingSRF drivers may now use Dash Windscreen Kit P/N 1180103 or P/N 180102.
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.
SRF3 New SRF Sectional Nose Rule Addition #26914wordingwordingSRF3 nose assembly must use approved multi-piece design; no modifications allowed except as specified.
STU Request to clarify afterrmarket side skirts exhaust exit #26814wordingwordingSTU 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 #26872wordingwordingSTU fender flare wording clarified: each fender may be flared up to 2" for tire clearance with 1% weight penalty.
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.
STU Request Ride Height Clarification #26597wordingwordingSTL 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 #26424wordingwordingSTU 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 #26564aeroaeroSTU 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 #26620wordingwordingSTU BMW S54B32 OEM reclassified from E46 designation, 3246 cc, 3300 lbs minimum weight.
SM Request to allow aftermarket fuel filters. #26370wordingwordingSM fuel pump and filter must be Mazda or OEM Equivalent part.
STU Request to Class Assignment for 2017 Civic #24287cars addedcars addedHonda Civic Si 2017- classified STU at 1500cc, 2800 lbs minimum with OEM engine and bodywork.
STU Request to run E46 3246cc in STU #25126cars addedcars addedSTU 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 #25899wordingwordingSTU Honda K24 may use intake part #s 17100-RRB-A00 or 17100-PRB-A10.
STU Request to Classify 12a Bridge Ported Rotary Engine #25985cars addedcars addedSTU 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 #26413aeroaeroSTU rear wing maximum cord length set to 12 inches, end plates to 72.0 square inches each.
SM Request 99-00 replacement Wire harnesses #25602wordingwordingSM 1999-2000 model year cars may use replacement Mazda ECU and injector harnesses, unmodified.
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.
SM Strike Tire Tread Language #26123wordingwordingSM removes tire tread protrusion beyond fender opening requirement from GCR 9.1.7.C.5.
STU Request to Equalize Direct Injected Turbo Cars #24890cars addedcars addedSTU 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.