Quickest here:P1 1:18.122 Todd Vanacore, Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta qualifying · STL 1:35.212 Danny Steyn, Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta race
P1STLsolid race · dashed qualifying · slower is lower
P1STLsolid race · dashed qualifying · each class's best lap as a share of P1's at the same event (the reference class, changeable above); 100% is level, higher is quicker
Event
P1
STL
Qual best
Race best
Trap
Qual best
Race best
Trap
vs P1
% of P1
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%)
3 rule changes (STL: 3)2 weight · 1 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. · 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
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.
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.
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%)
2 rule changes (P1: 1, STL: 1)2 wording · STL/STU: 90-05 Mazda Miata alternate front wheel hubs moved from General to specific part approval. · P1 now encourages unspecified engines including Diesel, hybrid, or electric via case-by-case request to Club Racing Board.showhide
STL Request to Remove Miata Hubs from General category #37138wordingneutralSTL/STU: 90-05 Mazda Miata alternate front wheel hubs moved from General to specific part approval.
P1 Update GCR section 9.1.8.B.J.7 #35907wordingneutralP1 now encourages unspecified engines including Diesel, hybrid, or electric via case-by-case request to Club Racing Board.
Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta ST24MAR082024-03-08
1:19.119Todd Vanacore · fastest of 3 · top 3 within 18.1s+0.997s (+1.28%)
1:19.924John Mcaleer · fastest of 3 · top 3 within 17.8s-0.010s (-0.01%)
139.8John Mcaleer-12.4 mph (-8.2%)
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%)
+16.929squal +17.237s
121.2%qual 121.8%
14 rule changes (P1: 9, STL: 5)2 engine · 2 induction · 1 weight · 9 wording · P1 removes redundant effective date language from engine stalling prohibition during SIR testing. · P1 Honda K20A-FD2 engine terminology corrected from 'spec' to proper series designation. · 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. · F600 Rotax 494, 493, 593 engines now require single expansion chamber and pull starter; electric starter optional. · P1 4-cycle 2000cc restrictor increases to 32mm, weight rises to 1450 lbs; 2300cc restrictor to 31mm, weight to 1475 lbs. · P1 Group CN Honda K20A-FD2 removes engine modification restrictions; CRB may add intake restrictor. · 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. · P1 SIR testing procedure modified: vehicle deemed compliant if stalls within 3 seconds. · P1 Single Inlet Restrictor wording clarified; all intake air or fuel-air mixture must pass through it. · P1 ducted air rule clarified: cockpit opening, fender louvers, and engine bay heat escape devices exempt from heat exchanger requirement. · STL ITA/ITS RX7 and 1985+ ITA/ITS/ITB/ITC vehicles clarified to conform to section 9.1.4.2 tire specifications. · P1 cockpit length dimension corrected from 23.662 to 23.622 inches; height and extension limits clarified with metric-imperial equivalents.showhide
P1 Remove redundant effective date language in GCR 9.1.8.B.J.4 #35693wordingneutralP1 removes redundant effective date language from engine stalling prohibition during SIR testing.
P1 Correct engine series terminology #35694wordingneutralP1 Honda K20A-FD2 engine terminology corrected from 'spec' to proper series designation.
STL ST Electric-Assisted Steering Systems #35066wordingneutralSTL and STU power steering rules clarified to permit electric-assisted and hydraulic-assisted steering systems.
STL BOP Adjustments #35112inductionfasterSTL Acura/Honda B-series and Mazda MZR restrictors reduced 2mm; minimum weights down 25–75 lbs for 1900–2000cc engines.
STL Mazda 12A #35320engineslowerSTL Mazda 12A must keep 5th and 6th intake port actuators and valves, no longer allowed removal or disabling.
P1 Please correct omitted punctuation #34890engineneutralF600 Rotax 494, 493, 593 engines now require single expansion chamber and pull starter; electric starter optional.
P1 Adjust restrictors and weights for Engine Table lines H and I #35229weightslowerP1 4-cycle 2000cc restrictor increases to 32mm, weight rises to 1450 lbs; 2300cc restrictor to 31mm, weight to 1475 lbs.
P1 Revise Group CN Honda K20A-FD2 Spec Line #35337wordingunclearP1 Group CN Honda K20A-FD2 removes engine modification restrictions; CRB may add intake restrictor.
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.
P1 SIR Testing #34354wordingneutralP1 SIR testing procedure modified: vehicle deemed compliant if stalls within 3 seconds.
P1 E&O Single Inlet Restrictor abbreviation, etc. #34369wordingneutralP1 Single Inlet Restrictor wording clarified; all intake air or fuel-air mixture must pass through it.
P1 E&O Clean up ducted air provision #34410wordingneutralP1 ducted air rule clarified: cockpit opening, fender louvers, and engine bay heat escape devices exempt from heat exchanger requirement.
STL Clarify STL table B - IT spec notes on Tires #34187wordingneutralSTL ITA/ITS RX7 and 1985+ ITA/ITS/ITB/ITC vehicles clarified to conform to section 9.1.4.2 tire specifications.
P1 E&O - Correct dimensional equivalents #34018wordingneutralP1 cockpit length dimension corrected from 23.662 to 23.622 inches; height and extension limits clarified with metric-imperial equivalents.
Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta ST23MAR102023-03-10
1:18.122Todd Vanacore · fastest of 5 · top 5 within 13.9s
1:19.934Jean-Luc Liverato · fastest of 3 · top 3 within 1.0s
152.2Jean-Luc Liverato
1:36.469Danny Steyn · fastest of 16 · top 5 within 3.9s
1:35.212Danny Steyn · fastest of 17 · top 5 within 3.8s
127.1Mike Taylor
+15.278squal +18.347s
119.1%qual 123.5%
78 earlier rule changes on record, in force before Atlanta Region Hoosier SCCA Super Tour @ Michelin Raceway Road Atlanta (from 2019)12 induction · 6 cars added · 6 engine · 5 weight · 4 aero · 2 removed · 1 tyres & wheels · 42 wording · P1 suspension covers must have symmetrical upper and lower surfaces, no airfoil shaping, cannot angle for downforce. · STL Spec MX5 clutch, wheels, and tyres specified: ACT 0000-02-5004-G6, 17x8 wheels, Toyo RR and RA1 235-40-17. · P1 aerodynamic devices limited to 1cm below lower surfaces rear of front axle; body panels covering suspension cannot be airfoil-shaped. · P1 forced induction banned: turbocharging and supercharging no longer allowed. · P1 motorcycle-based engines with individual throttle bodies must install flat plate restrictors within 4 inches of primary butterfly. · P1 bodywork rules clarified: cycle fenders prohibited, side body minimum height at front axle centerline required, air ducting for downforce banned. · 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. · P1 2-cycle 6-cylinder displacement increases to 1725 cc, restrictor shrinks to 40mm, minimum weight drops to 1275 lbs. · 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. · P1 splits 2000cc and 2300cc engines into separate spec lines H and I with dedicated minimum weights. · P1 Staudacher cars with 38.5mm flat plate intake restrictor reduced to 950 lbs minimum weight. · STL Spec MX-5 removes redundant specification line; no performance change. · P1 adds 1355cc motorcycle-based engine spec line with no restrictor required, minimum weight 1075 lbs. · STL Volkswagen 2.0L TFSI 1984cc classified with turbocharger removal required, meeting all other STL specs. · P1 tonneau cover wording clarified: equipment must be securely attached; covers allowed for minimum dimensions. · P1 Staudacher with 1005cc homologated before 1-1-2014 may run 38.5mm flat plate intake restrictor at 950 lbs minimum weight. · P1 Spec Lines C and G: intake restrictor rules clarified with specific displacement and weight thresholds; wording standardized. · P1 Spec Lines B, C, D maximum valves per cylinder set to 4, was NA. · 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. · P1 Spec Line A clarifies carburetor induction only, one per cylinder, balance tubes not allowed. · P1 Spec Line H notes clarify peripheral port or bridgeport allowed. · ST oil coolers and filters now explicitly allowed to be added or substituted; wording clarifies existing permissions. · P1 Elan DP02 Mazda MZR sealed engine option removal effective 3/1/2021. · P1 engine table updates terminology from inlet to intake restrictor across multiple spec lines. · 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. · 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. · 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. · P1 intake manifolds unrestricted on engines without flat plate restrictor; plenums and balance pipes prohibited on individual runner manifolds with 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. · P1 sealed DP02-spec 2.0L Mazda MZR Elan removal date extended from 1/1/2020 to 1/1/2021. · P1 sealed DP02-spec 2.0 MZR engine removed effective 1/1/2020; competitors may use Spec Line G. · P1 Spec Line F Honda K20A-FD2 reclassified from Restricted 2.0L Group to CN-spec with stock intake manifold and 64mm throttle body. · Mazda Spec MX-5 Challenge classified in STL with 2000cc displacement and 2500 lbs minimum weight. · P1 traction control prohibited in GCR section 9.1.8.C.H. · P1 allows mechanical and solenoid shifters, prohibits electronic controls and pre-selected changes. · P1 bodywork minimum height provision moved to aerodynamic section; 115cm height limit for aero parts added. · P1 clarifies fender louver and brake duct rules, consolidating duplicative provisions in GCR 9.1.8.C. · STU alternate intake manifolds now allowed case-by-case instead of prohibited. · P1 anti-intrusion panels now allowed anywhere on chassis sides, previously restricted. · P1 bodywork wording corrected: 'a passenger' becomes 'passenger' in three GCR sections. · STL Acura/Honda B18 except C engine restrictor increases from 53mm to 54mm flat plate. · P1 Engine Table reference cleaned up; no performance change. · P1 Mazda Renesis Rotary removed from Engine Table specification line. · STL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld. · P1 Staudacher and Honda K20A-FD2 engine table language cleaned up; no performance changes. · P1 closed cockpit single-seat cars moved from subsection J.5 to subsection B.4; prohibition unchanged. · 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. · P1 engine table reference corrected from 'above' to 'below'; ECU throttle wording clarified for dual sensors and fail-safes. · P1 removes redundant TIR inlet restrictor provisions; SIR and flat plate restrictors remain required. · P1 Honda K20A-FD2 CN-spec clarifies allowed parts to OEM list only, no machining. · P1 engine table wording corrected; head designs removed from listed specifications. · 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
P1 November 2022 Rules Clarification for Suspension Covers #33615aeroslowerP1 suspension covers must have symmetrical upper and lower surfaces, no airfoil shaping, cannot angle for downforce.
STL Spec MX5 in STL #33473wordingneutralSTL Spec MX5 clutch, wheels, and tyres specified: ACT 0000-02-5004-G6, 17x8 wheels, Toyo RR and RA1 235-40-17.
P1 Clarify body panel coverage of suspension components #33318aeroslowerP1 aerodynamic devices limited to 1cm below lower surfaces rear of front axle; body panels covering suspension cannot be airfoil-shaped.
P1 E&O clarification regarding forced induction #33123inductionslowerP1 forced induction banned: turbocharging and supercharging no longer allowed.
P1 Clarify authorization to use flat plate intake restrictor #32964wordingneutralP1 motorcycle-based engines with individual throttle bodies must install flat plate restrictors within 4 inches of primary butterfly.
P1 E&O Clarification of Bodywork Rules #32468wordingneutralP1 bodywork rules clarified: cycle fenders prohibited, side body minimum height at front axle centerline required, air ducting for downforce banned.
STL Single TB Weight Modifiers #31449weightfasterSTU normally aspirated engines: minimum weights reduced up to 310 lbs; single throttle body weight reduction removed.
STL Improved Touring Tires #32063tyres & wheelsneutralSTL and STU Improved Touring vehicles must conform to 9.1.4 Tires & Wheels requirements.
P1 Displacement & Weight Change Request for 2-Cycle 6 Cylinder #31609enginefasterP1 2-cycle 6-cylinder displacement increases to 1725 cc, restrictor shrinks to 40mm, minimum weight drops to 1275 lbs.
STL Throttling Device Clarification #31323wordingneutralSTL and STU piston engines clarified: intake manifold and cylinder head porting remains free.
STL Mazda Renesis Restriction #31467inductionfasterSTL Mazda Renesis flat plate restrictor increases from 55mm to 60mm.
STL Clarification of 79-85 RX7 Spec line #31621wordingneutralSTL Mazda RX-7 12A 79-85 clarifies carburetor, emissions, and water jacket modification rules.
P1 Move 2000cc and 2300cc engine options to individual spec lines #31012wordingneutralP1 splits 2000cc and 2300cc engines into separate spec lines H and I with dedicated minimum weights.
P1 E&O Spec Line B notes #31095weightfasterP1 Staudacher cars with 38.5mm flat plate intake restrictor reduced to 950 lbs minimum weight.
STL Request to clean up Spec MX-5 Redundancy #31069wordingneutralSTL Spec MX-5 removes redundant specification line; no performance change.
P1 Add 1355cc spec line #30890cars addedneutralP1 adds 1355cc motorcycle-based engine spec line with no restrictor required, minimum weight 1075 lbs.
STL VW Engine Request #30625engineslowerSTL Volkswagen 2.0L TFSI 1984cc classified with turbocharger removal required, meeting all other STL specs.
P1 E&O tonneau cover provision in cockpit opening section #30458wordingneutralP1 tonneau cover wording clarified: equipment must be securely attached; covers allowed for minimum dimensions.
P1 Update Spec Line B Notes #30498wordingneutralP1 Staudacher with 1005cc homologated before 1-1-2014 may run 38.5mm flat plate intake restrictor at 950 lbs minimum weight.
P1 Update Spec Lines C and G notes #30499wordingneutralP1 Spec Lines C and G: intake restrictor rules clarified with specific displacement and weight thresholds; wording standardized.
P1 E&O Maximum Valves Per Cylinder #30559engineunclearP1 Spec Lines B, C, D maximum valves per cylinder set to 4, was NA.
STL Request Mazda B5 DOHC #30420cars addedneutralSTL Mazda B5 DOHC added to classification with standard STL regulations.
STL Honda B16A (JDM) Restrictor change #30531inductionslowerSTL Honda B16A JDM restrictor reduced from 54mm to 53mm.
P1 Clean up Spec Line A notes section #30424wordingneutralP1 Spec Line A clarifies carburetor induction only, one per cylinder, balance tubes not allowed.
P1 Clean up Spec Line H notes section #30425wordingneutralP1 Spec Line H notes clarify peripheral port or bridgeport allowed.
STL ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wordingneutralST oil coolers and filters now explicitly allowed to be added or substituted; wording clarifies existing permissions.
P1 E&O restrictor terminology #30285wordingneutralP1 engine table updates terminology from inlet to intake restrictor across multiple spec lines.
STL GM Ecotec engines in STL #30247wordingneutralSTL GM Ecotec engines now permit any combination within the family, must use 55mm flat plate restrictor.
STL Super Touring Alternate Miata Hubs #30345wordingneutralSTL/STU 90-05 Mazda Miata gains approval for Mazda Motorsports Development alternate front wheel hubs.
STL Brake Component Relocation #29990wordingneutralST cars may relocate ABS actuation hardware and wiring anywhere in engine compartment.
STL Super Touring Wing Clarification #30111aeroneutralSTL rear wing trailing edge, including end plates and gurney flap, maximum rearward mounting clarified to center of rearmost bodywork.
STL Transmission Options #30118wordingneutralSTL allows OEM gear sets from same manufacturer transmissions with input shaft modifications for fitment.
STL Request for FWD and RWD Parity #29728weightfasterSTL RWD strut suspension weight penalty cut to 0.5%, other RWD cut to 2.5%.
STL Request to Remove Honda F20C 2% Weight Penalty #29815weightfasterSTL Honda F20C loses 2% weight penalty, minimum weight reduced by approximately 35 lbs.
STL Request for FWD and RWD Parity #30023inductionslowerSTL Honda B16/B17/B18C1 restrictor tightened to 53mm; B18C variants and Mazda MZR to 52mm.
STL Request clarification on wing measurement #29640aeroneutralST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch.
STL Minimum Weight Determination #27695wordingneutralSTL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis adjustments.
STL ST Gurney flap Wicker clarification #29012wordingneutralSTL and STU rear wing rules clarify that wicker is a Gurney flap; no performance change.
STL Request for Addition to GT3 Approved Turbo List #27576wordingneutralGT3 and STU add Borg-Warner EFR6258 to approved turbocharger list.
STL Request to add 2016-2019 GMX-5 Spec line #28604cars addedneutralSTL adds 2016-2019 Mazda MX-5 Global Cup at 2000cc, 2450-2550 lbs minimum weight.
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.
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.
P1 E&O minimum weights and intake manifolds #28731inductionfasterP1 intake manifolds unrestricted on engines without flat plate restrictor; plenums and balance pipes prohibited on individual runner manifolds with restrictor.
STL STL Honda B18 restrictor changes #28794inductionfasterSTL Honda B18 restrictor reduced from 54mm to 53mm flat plate; B18C1 added with 54mm restrictor.
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.
STL Acura/Honda B18C engine chart. Reduce the current 54 mm flat plat #28663inductionslowerSTL Mazda MZR restrictor reduced from 54 mm to 53 mm.
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.
STL Request to add wheel part numbers #28342wordingneutralSTL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL.
P1 Extend date for removing sealed DP02-spec 2.0L option #28046wordingneutralP1 sealed DP02-spec 2.0L Mazda MZR Elan removal date extended from 1/1/2020 to 1/1/2021.
P1 Remove sealed DP02-spec 2.0 MZR spec #26753removedslowerP1 sealed DP02-spec 2.0 MZR engine removed effective 1/1/2020; competitors may use Spec Line G.
P1 Update Revised Spec Line F #27745engineunclearP1 Spec Line F Honda K20A-FD2 reclassified from Restricted 2.0L Group to CN-spec with stock intake manifold and 64mm throttle body.
STL Request to Classify Spec MX-5 Challenge in STL #27399cars addedneutralMazda Spec MX-5 Challenge classified in STL with 2000cc displacement and 2500 lbs minimum weight.
P1 E&O Transmissions #27098wordingunclearP1 traction control prohibited in GCR section 9.1.8.C.H.
P1 E&O Transmissions #27005wordingneutralP1 allows mechanical and solenoid shifters, prohibits electronic controls and pre-selected changes.
P1 Move minimum height provision to #27031wordingneutralP1 bodywork minimum height provision moved to aerodynamic section; 115cm height limit for aero parts added.
P1 Remove duplicative fender louver provision #27033wordingneutralP1 clarifies fender louver and brake duct rules, consolidating duplicative provisions in GCR 9.1.8.C.
STL Request clarification for manifold and throttle in STU #27004inductionfasterSTU alternate intake manifolds now allowed case-by-case instead of prohibited.
P1 Missing word E&O #26919wordingneutralP1 anti-intrusion panels now allowed anywhere on chassis sides, previously restricted.
P1 E&O correction to GCR 9.1.8.C.C. #26927wordingneutralP1 bodywork wording corrected: 'a passenger' becomes 'passenger' in three GCR sections.
STL Request Restrictor Plate correction #26779inductionfasterSTL Acura/Honda B18 except C engine restrictor increases from 53mm to 54mm flat plate.
P1 Clean up reference to engine table #26648wordingneutralP1 Engine Table reference cleaned up; no performance change.
P1 Remove redundant spec line #26692removedneutralP1 Mazda Renesis Rotary removed from Engine Table specification line.
STL Request Ride Height Clarification #26597wordingneutralSTL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld.
P1 Clean Up Engine Table Language #26590wordingneutralP1 Staudacher and Honda K20A-FD2 engine table language cleaned up; no performance changes.
P1 Move single-seat closed cockpit provision to #26376wordingneutralP1 closed cockpit single-seat cars moved from subsection J.5 to subsection B.4; prohibition unchanged.
STL Request to reduce weight of RX8 with Renesis rotary #25781weight -100 lbsfasterSTL Mazda Renesis minimum weight reduced from 2800 to 2700 lbs.
STL Request for Open Brake Pads On Mazda MX-5 Cup NC #25821wordingneutralSTL Mazda MX-5 Cup brake pad compound changed to open.
STL Request to clarify B18C1 GSR Honda B motor table #26209cars addedneutralSTL adds Acura/Honda B18C1 GSR with 54mm flat plate restrictor and port matching limited to 1 inch.
STL Port Matching #26415wordingfasterSTL Mazda 12 and 13B now permit port matching; previous ban removed.
P1 Correct errors in GCR section 9.1.8.C.J #26144wordingneutralP1 engine table reference corrected from 'above' to 'below'; ECU throttle wording clarified for dual sensors and fail-safes.
P1 Remove redundant inlet restrictor provisions #25877wordingneutralP1 removes redundant TIR inlet restrictor provisions; SIR and flat plate restrictors remain required.
P1 Clarify Honda K20A-FD2 parts requirement #25949wordingneutralP1 Honda K20A-FD2 CN-spec clarifies allowed parts to OEM list only, no machining.
P1 Correct GCR section 9.1.8.C.J errors #25966wordingneutralP1 engine table wording corrected; head designs removed from listed specifications.
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.
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 P1" is the class's best as a share of P1'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 P1'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.