BoP Lab / Hallett Motor Racing Circuit

STL vs FV pace at Hallett Motor Racing Circuit

Quickest here: STL 1:24.620 William Knight, AVRG Green Country Grand Prix 2024 qualifying · FV 1:25.682 Hunter Phelps-Barron, AVRG Green Country Grand Prix 2026 race

Lap times% of STL

STLFVsolid race · dashed qualifying · slower is lower

STLFVsolid 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			FV
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs STL	% of STL
	AVRG Green Country Grand Prix 2026 AVRGGR262026-04-25	1:25.053Ryan Gutile · fastest of 6 · top 5 within 2.7s-1.818s (-2.09%)	1:25.945Ryan Gutile · fastest of 6 · top 5 within 0.6s-0.486s (-0.56%)	101.3Amy Mills+1.8 mph (+1.8%)	1:26.124Zachary Whitston · fastest of 9 · top 5 within 3.0s-5.838s (-6.35%)	1:25.682Hunter Phelps-Barron · fastest of 9 · top 5 within 3.3s-6.747s (-7.30%)	94.7Zachary Whitston+5.0 mph (+5.6%)	-0.263squal +1.071s	99.7%qual 101.3%
4 rule changes (STL: 4)2 weight · 1 cars added · 1 wording · STL adds Mazda BP 1.6 engine, 1600cc displacement, minimum weight 2160 lbs. · 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 2026-04-01 STL Classifications #39885cars addedneutralSTL adds Mazda BP 1.6 engine, 1600cc displacement, minimum weight 2160 lbs. 2026-01-01 STL Weight adjustment for STL #39579weightslowerSTL minimum weights increase across all classes, 1300 cc gains 195 lbs to 1950, up to 1850 cc at 2500. 2025-08-01 STL Lotus Weight Reduction #38772weight -50 lbsfasterSTL/STU Lotus weight reduced: Evora GT4 to 2700 lbs, Elise Cup R to 2250 lbs, Elise/Exige SC to 2450-2550 lbs. 2025-05-01 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.
	AVRG Green Country Grand Prix 2025 AVRGGR252025-04-26	1:26.871Bryan Heitman · fastest of 4 · top 4 within 5.0s+2.251s (+2.66%)	1:26.431Bryan Heitman · fastest of 5 · top 5 within 6.7s+0.766s (+0.89%)	99.5Jim Ebben-2.8 mph (-2.8%)
2 rule changes (STL: 1, FV: 1)1 suspension & brakes · 1 wording · STL/STU: 90-05 Mazda Miata alternate front wheel hubs moved from General to specific part approval. · FV ferrous rotor no longer required to be smooth; may have up to three pad cleaning grooves per side.showhide 2024-12-01 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. 2024-10-01 FV Disc Brakes #36822suspension & brakesneutralFV ferrous rotor no longer required to be smooth; may have up to three pad cleaning grooves per side.
	AVRG Green Country Grand Prix 2024 AVRGGR242024-04-20	1:24.620William Knight · fastest of 5 · top 5 within 4.1s	1:25.665Jake Anton · fastest of 4 · top 4 within 3.5s	102.4William Knight	1:31.962Michael Nitz · fastest of 4 · top 4 within 12.7s	1:32.429Mark Richardson · fastest of 5 · top 5 within 7.3s	89.7Mark Richardson	+6.764squal +7.342s	107.9%qual 108.7%
65 earlier rule changes on record, in force before AVRG Green Country Grand Prix 2024 (from 2019)12 induction · 6 tyres & wheels · 5 cars added · 5 weight · 3 aero · 3 engine · 31 wording · STL and STU power steering rules clarified to permit electric-assisted and hydraulic-assisted steering systems. · STL Acura/Honda B-series and Mazda MZR restrictors reduced 2mm; minimum weights down 25–75 lbs for 1900–2000cc engines. · STL Mazda 12A must keep 5th and 6th intake port actuators and valves, no longer allowed removal or disabling. · STL Mazda RX-7 12A (79-85) now allows auto-type 2 bbl with 42mm choke(s) on dual-y manifold as alternate to stock Nikki 4 bbl. · FV front wheel bearings wording clarified in GCR 9.1.1.C.10.G. · STL ITA/ITS RX7 and 1985+ ITA/ITS/ITB/ITC vehicles clarified to conform to section 9.1.4.2 tire specifications. · STL Spec MX5 clutch, wheels, and tyres specified: ACT 0000-02-5004-G6, 17x8 wheels, Toyo RR and RA1 235-40-17. · FV connecting rod rules add Brian Crower part #BC6417 and Newland Group #4M113077 as allowed replacements. · FV connecting rods minimum weight 425.0 grams, center-to-center length 130 ± 0.10/-0.25 mm specified. · 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. · FV connecting rod suppliers clarified: Crower SP93280B and BrianCrower BC6417 allowed as direct replacements. · 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. · FV allows Crower SP93280B and Brian Crower Racing Rods as direct replacement connecting rods, must meet OEM minimum weight. · STL Spec MX-5 removes redundant specification line; no performance change. · 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. · ST oil coolers and filters now explicitly allowed to be added or substituted; wording clarifies existing permissions. · 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. · FV now allows 4 bolt wheels, previously restricted to 5 bolt wheels. · FV now supports 4-bolt pattern wheels in addition to existing wheel specifications. · GT3 and STU add Borg-Warner EFR6258 to approved turbocharger list. · STL adds 2016-2019 Mazda MX-5 Global Cup at 2000cc, 2450-2550 lbs minimum weight. · STL Mazda MX-5 Club Model 06-15 allows Mazda header part number 0000-06-5407-NC. · STL Honda/Acura B18 non-C gets 54mm restrictor; B18C variants drop B18C1, get 53mm restrictor. · STL Honda B18 restrictor reduced from 54mm to 53mm flat plate; B18C1 added with 54mm restrictor. · STU GM Ecotech LNF now allowed with turbo removed or with LE5 head and intake manifold, meeting STL specs. · STL Mazda MZR restrictor reduced from 54 mm to 53 mm. · STL Mazda MZR restrictor reduced from 55 mm to 53 mm. · FV rain tire requirement changed to Hoosier #44266 22.5 x 5.0 x 15 WET or W3. · STL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL. · FV allows non-spec Hoosier tires in Regional races until 2020-01-01, when spec tires become required. · FV allows rear tires on front of car; mandates Hoosier #43337 fronts and #43353 rears, plus #44266 rain tire from 2020-01-01. · FV wheels clarified: 15" x 4J standard or 15" x 4.5J steel VW, 5-bolt pattern, same track dimensions. · FV exhaust outlet location tightened to 1–4 inches behind rearmost body part. · Mazda Spec MX-5 Challenge classified in STL with 2000cc displacement and 2500 lbs minimum weight. · FV wheels now permit 15-inch 4.5J steel wheels within C.2 track dimensions, adding to standard 4J options. · STU alternate intake manifolds now allowed case-by-case instead of prohibited. · FV exhaust opening can now extend to 4 inches behind body rear, previously 3 inches maximum. · STL Acura/Honda B18 except C engine restrictor increases from 53mm to 54mm flat plate. · FV front track maximum 52.500" and rear track 49.125"-50.750" no longer prohibits spacers. · STL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld. · FV disc brake assembly minimum weight clarified to 16.5 lbs total; caliper minimum weight requirement removed. · 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. · FV intake manifold horizontal tube measurement locations clarified between 1.500" and 8.000" on short side. · 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 2024-02-01 STL ST Electric-Assisted Steering Systems #35066wordingneutralSTL and STU power steering rules clarified to permit electric-assisted and hydraulic-assisted steering systems. 2024-02-01 STL BOP Adjustments #35112inductionfasterSTL Acura/Honda B-series and Mazda MZR restrictors reduced 2mm; minimum weights down 25–75 lbs for 1900–2000cc engines. 2024-02-01 STL Mazda 12A #35320engineslowerSTL Mazda 12A must keep 5th and 6th intake port actuators and valves, no longer allowed removal or disabling. 2024-01-01 STL Alternate Carburetor Request for 79-85 RX7 12a #35181inductionunclearSTL Mazda RX-7 12A (79-85) now allows auto-type 2 bbl with 42mm choke(s) on dual-y manifold as alternate to stock Nikki 4 bbl. 2023-12-01 FV FV Wheel Bearing Clarification #35150wordingneutralFV front wheel bearings wording clarified in GCR 9.1.1.C.10.G. 2023-06-01 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. 2023-01-01 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. 2022-03-01 FV Connecting Rod Update Request for 9.1.1.C Formula Vee (FV) 5.C.6 #32160wordingneutralFV connecting rod rules add Brian Crower part #BC6417 and Newland Group #4M113077 as allowed replacements. 2022-03-01 FV E&O clarification of connecting rod center-to-center length #32183wordingneutralFV connecting rods minimum weight 425.0 grams, center-to-center length 130 ± 0.10/-0.25 mm specified. 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 & wheelsneutralSTL and STU Improved Touring vehicles must conform to 9.1.4 Tires & Wheels requirements. 2022-01-01 FV Update direct replacement connecting rod information #31843wordingneutralFV connecting rod suppliers clarified: Crower SP93280B and BrianCrower BC6417 allowed as direct replacements. 2022-01-01 STL Throttling Device Clarification #31323wordingneutralSTL 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 #31621wordingneutralSTL Mazda RX-7 12A 79-85 clarifies carburetor, emissions, and water jacket modification rules. 2021-12-01 FV Formula V Connecting Rod Replacement #31448wordingneutralFV allows Crower SP93280B and Brian Crower Racing Rods as direct replacement connecting rods, must meet OEM minimum weight. 2021-09-01 STL Request to clean up Spec MX-5 Redundancy #31069wordingneutralSTL Spec MX-5 removes redundant specification line; no performance change. 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 #30183wordingneutralSTL Pontiac Solstice/Saturn Sky allowed 4" ride height. 2021-05-01 STL Request Mazda B5 DOHC #30420cars addedneutralSTL 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 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. 2021-03-01 STL GM Ecotec engines in STL #30247wordingneutralSTL 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 #30345wordingneutralSTL/STU 90-05 Mazda Miata gains approval for Mazda Motorsports Development alternate front wheel hubs. 2021-02-01 STL Brake Component Relocation #29990wordingneutralST cars may relocate ABS actuation hardware and wiring anywhere in engine compartment. 2021-02-01 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. 2021-02-01 STL Transmission Options #30118wordingneutralSTL allows OEM gear sets from same manufacturer transmissions with input shaft modifications for fitment. 2021-01-01 STL Request for FWD and RWD Parity #29728weightfasterSTL RWD strut suspension weight penalty cut to 0.5%, other RWD cut to 2.5%. 2021-01-01 STL Request to Remove Honda F20C 2% Weight Penalty #29815weightfasterSTL Honda F20C loses 2% weight penalty, minimum weight reduced by approximately 35 lbs. 2021-01-01 STL Request for FWD and RWD Parity #30023inductionslowerSTL Honda B16/B17/B18C1 restrictor tightened to 53mm; B18C variants and Mazda MZR to 52mm. 2020-12-01 STL Request clarification on wing measurement #29640aeroneutralST aero devices and reference areas now include end plates but exclude fasteners protruding over 1/2 inch. 2020-08-01 STL Minimum Weight Determination #27695wordingneutralSTL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis adjustments. 2020-08-01 STL ST Gurney flap Wicker clarification #29012wordingneutralSTL and STU rear wing rules clarify that wicker is a Gurney flap; no performance change. 2020-07-01 FV Support for Recommended Item - 4 bolt wheels in FV #29084tyres & wheelsneutralFV now allows 4 bolt wheels, previously restricted to 5 bolt wheels. 2020-07-01 FV Support for 4-bolt pattern wheels #28955 #29118wordingneutralFV now supports 4-bolt pattern wheels in addition to existing wheel specifications. 2020-07-01 STL Request for Addition to GT3 Approved Turbo List #27576wordingneutralGT3 and STU add Borg-Warner EFR6258 to approved turbocharger list. 2020-06-01 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. 2020-06-01 STL Request to update PN for MX-5 #28622wordingunclearSTL Mazda MX-5 Club Model 06-15 allows Mazda header part number 0000-06-5407-NC. 2020-06-01 STL Correction - Clarification Honda/Acura B18B engine Letter # 26209 #28873inductionunclearSTL Honda/Acura B18 non-C gets 54mm restrictor; B18C variants drop B18C1, get 53mm restrictor. 2020-05-01 STL STL Honda B18 restrictor changes #28794inductionfasterSTL Honda B18 restrictor reduced from 54mm to 53mm flat plate; B18C1 added with 54mm restrictor. 2020-04-01 STL Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0 #27884engineslowerSTU GM Ecotech LNF now allowed with turbo removed or with LE5 head and intake manifold, meeting STL specs. 2020-04-01 STL Acura/Honda B18C engine chart. Reduce the current 54 mm flat plat #28663inductionslowerSTL Mazda MZR restrictor reduced from 54 mm to 53 mm. 2020-04-01 STL Mazda MZR engine chart. Reduce the current 55 mm flat plate to 53 #28664inductionslowerSTL Mazda MZR restrictor reduced from 55 mm to 53 mm. 2020-03-01 FV Update rain tire designation #28444tyres & wheelsneutralFV rain tire requirement changed to Hoosier #44266 22.5 x 5.0 x 15 WET or W3. 2020-03-01 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. 2020-01-01 FV FV Allow non-spec tire in Regional competition #26284tyres & wheelsneutralFV allows non-spec Hoosier tires in Regional races until 2020-01-01, when spec tires become required. 2020-01-01 FV Request to Allow Rear Tires on the Front of Formula Vee #26537tyres & wheelsneutralFV allows rear tires on front of car; mandates Hoosier #43337 fronts and #43353 rears, plus #44266 rain tire from 2020-01-01. 2019-12-01 FV Clarification on Wheel Bolt Pattern #27603wordingneutralFV wheels clarified: 15" x 4J standard or 15" x 4.5J steel VW, 5-bolt pattern, same track dimensions. 2019-10-01 FV Allowed Modifications E&O #27398wordingneutralFV exhaust outlet location tightened to 1–4 inches behind rearmost body part. 2019-10-01 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. 2019-08-31 FV E&O Wheels #27230tyres & wheelsneutralFV wheels now permit 15-inch 4.5J steel wheels within C.2 track dimensions, adding to standard 4J options. 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 FV Exhaust termination rule E&O #26702aeroneutralFV exhaust opening can now extend to 4 inches behind body rear, previously 3 inches maximum. 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 FV E&O Dimensions #26674wordingneutralFV front track maximum 52.500" and rear track 49.125"-50.750" no longer prohibits spacers. 2019-05-01 STL Request Ride Height Clarification #26597wordingneutralSTL and STU ride height measurement clarified: without driver, at rocker panel lowest point, excluding pinch weld. 2019-04-01 FV Request to clarify Disc Brake rules bearing retainer & weights #26262weightslowerFV disc brake assembly minimum weight clarified to 16.5 lbs total; caliper minimum weight requirement removed. 2019-03-01 STL Request to Allow VW 1.8L Engine #25614cars addedneutralSTL 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 #25821wordingneutralSTL Mazda MX-5 Cup brake pad compound changed to open. 2019-03-01 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. 2019-03-01 STL Port Matching #26415wordingfasterSTL Mazda 12 and 13B now permit port matching; previous ban removed. 2019-02-01 FV FV Intake Manifold Clarification #26008wordingneutralFV intake manifold horizontal tube measurement locations clarified between 1.500" and 8.000" on short side. 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.