Lap times across years say as much about the weather as the class. % of STL is each class's best lap as a share of STL's on the same day, so the conditions drop out: 100% is level, less is quicker, and a move in it is the class getting faster or slower against the field.
Quickest here:STL 1:35.439 John Schmitt, Runoffs 2016 qualifying · AS 1:30.651 Tom Sloe, Runoffs 2016 qualifying · T4 1:38.813 Jonathan Yanca, Runoffs 2016 qualifying · FP 1:35.938 John Walker, Runoffs 2016 qualifying
STLAST4FPsolid race · dashed qualifying · slower is lower
STLAST4FPsolid 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, less is quicker, so up the chart is quicker
2:30.537Derek Ketchie · fastest of 16 · top 5 within 2.9s-1.528s (-1.00%)
2:30.657Danny Steyn · fastest of 16 · top 5 within 0.6s-1.470s (-0.97%)
134.8Mike Taylor+2.6 mph (+2.0%)
2:26.911Andrew McDermid · fastest of 8 · top 5 within 3.4s+0.119s (+0.08%)
2:28.471Andrew McDermid · fastest of 8 · top 5 within 2.4s-0.761s (-0.51%)
151.0Andrew McDermid-0.6 mph (-0.4%)
-2.186squal -3.626s
98.5%qual 97.6%
2:35.876Matt Spicuzzi · fastest of 12 · top 5 within 2.4s+2.920s (+1.91%)
2:35.757Matt Spicuzzi · fastest of 12 · top 5 within 2.7s+3.124s (+2.05%)
127.6Matt Spicuzzi-6.0 mph (-4.5%)
+5.100squal +5.339s
103.4%qual 103.5%
2:33.275Stephen Simonds · fastest of 26 · top 5 within 1.0s+0.880s (+0.58%)
2:33.240David Strittmatter · fastest of 25 · top 5 within 1.7s-1.031s (-0.67%)
132.4David Strittmatter±0.0 mph (±0.0%)
+2.583squal +2.738s
101.7%qual 101.8%
77 rule changes (STL: 4, AS: 13, T4: 26, FP: 34)15 cars added · 14 weight · 9 induction · 6 engine · 5 suspension & brakes · 3 tyres & wheels · 2 removed · 1 aero · 12 wording · 10 other · AS Camaro 16+ Spec Line: 1LE front splitter kit permitted, belt tensioner and motor mount parts allowed, spark plug position defined. · AS class adds Pirelli P Zero Trofeo Track as permitted tyre option for competition. · AS class rear trailing arms no longer required to maintain stock length, only to locate rear axle. · AS Ford Mustang GT 4.6L 4-valve regains allowance, minimum weight 3200 lbs. · AS Ford Mustang Coupe GT 05-14 Gen3 Coyote minimum weight increases from 3100 to 3400 lbs. · HP Mini Cooper 02-06 compression ratio increases from 10.6 to 11.0:1. · 1996-2000 Honda Civic CX/DX/LX with D16Y7 engine newly classified in HP. · HP 1275 Midget/Sprite alternate intake manifold from MG-B now permitted; balance tube shortening and flange modification allowed. · HP Honda Civic DX/LX 92–95 wheels 13x7 to 15x7, weight 2420 to 2350 lbs. · STL removes Mazda MX-5 Cup entirely; renames Spec MX5 Challenge to Spec MX5; renames Global Cup to MX-5 Cup (16-18); removes Global Cup (2019). · AS GM LM7 5.3L must use full prep Holley carburetor as described in 9.1.6.D.c.1, not specifically 4776. · STL, STU weight calculation procedure clarified: positive percentages added first, negative subtracted second, then fixed weights applied. · EP Mazda MX-5 94-97 front track widens to 1516 mm, rear to 1534 mm. · FP Volkswagen Jetta 82-84 carburation option 2 comma removed; all five models' carb specs clarified or confirmed. · FP Spec Line Volkswagen Rabbit and Scirocco 1789cc base weight corrected to 1803 lbs. · EP Triumph GT6 auto-type drivetrain choke size increases from 44mm to 45mm. · BMW E21 320i/is (80–83) newly classified in HP Spec Lines effective 2026-05-01. · HP BMW 318is 84-85 displacement corrected to 1767 cc, 89.0 x 71.0 mm bore and stroke. · AS EFI engine build sheets add dry sump, header, camshaft, and timing chain tensioner options for LS, LT1, Ford, and Mopar engines. · AS LT1 Camaro engine build sheet added with full specs; LT1 weight 3200 lbs, GTO tire to 275, Mustang weight to 3525 lbs, oil catch tanks now required. · STL adds Mazda BP 1.6, 1600cc, minimum weight 2160 lbs. · AS Spec Lines reorganized for 2026; detailed chassis, engine, weight, wheelbase, tire and brake specifications moved to main rules and engine build sheets. · FP Fiat X-1/9 1300 and 1500 intake and exhaust valve sizes corrected to 36.3/(1.43) and 31.2-33.3/(1.23-1.31). · FP Fiat X-1/9 & Bertone dual carburetors choke size increases from 28mm to 30mm on intake runner manifold. · AS GM LM7 5.3L gains Edelbrock 71187 intake manifold, MSD 6014 ignition box, Holly 4776 carb option under full prep spec line. · FP adds Toyota 5E 1497cc DOHC engine, 1900 lbs, 23mm restrictor, SIR fuel induction. · FP class adds Toyota 4E DOHC 1331 cc engine, 1900 lbs minimum weight, unrestricted fuel induction. · FP Fiat X1/9 fuel injection carburetors simplified to one 36 or 40 DCNF option; exhaust valve enlarged to 33.0/1.30. · T2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously only spherical bearings permitted. · AS Ford Mustang and Mercury Capri with Restricted Prep engines get 61 mm restrictor, down from 64 mm. · STL minimum weights increase across all engine sizes, 1300cc to 1850cc up to 195–250 lbs. · T2, T3, T4 now allow under-dash electronics relocation for access after roll cage installation. · T4 Performance clarified: 1-piece alternative rotors permitted only at sizes listed in spec line; alternate brake kits may use matching 1-piece rotors. · AS Ford Mustang GT 94-04 Restricted Prep Engine now permits Ford Motorsport M-6250-F303 camshaft. · EP Triumph TR2–TR4A may use 5-speed gearbox without overdrive; Weber carburetors and weight reference deleted. · EP BMW Z3 2.5L and other models get smaller restrictors, 50mm to 55mm, and Z3 2.5L weight rises 50 to 78 lbs. · FP Lancia Scorpion minimum weight cut to 1950 lbs from 2030 lbs. · FP VW Rabbit Convertible no longer required to remove factory roll bar. · FP Acura Integra and Honda Civic models gain 50–79 lbs minimum weight; Mazda Miata and Mercury Capri compression ratio to 11.0:1 and valve lift to .425". · FP Honda D15, D16, B16A, B18 engines gain 105–120 lbs minimum weight across seven configurations. · AS Cadillac CTS-V 04-07 Restricted Prep minimum weight drops to 3400 lbs. · EP Nissan 280Z minimum weight lowered to 2400 lbs, 2460 lbs with *, 2520 lbs with **. · EP Mazda MX-5 1.8L 90-97 minimum weight reduced to 2125 lbs. · HP Spec Lines Austin-Healey Sprite/Midget 1098cc minimum weight drops to 1550 lbs. · HP Volvo 142 P-1800 engine gains compression ratio limit 12.0:1 and valve lift limit .425 inch. · HP Mini DOHC 1.6 valve lift limit drops to .390" from .450". · FP Scirocco 83–88 classified Prep Level 1: 1733–1803 lbs, 1715–1780 cc, iron block, aluminium head, carburetted or fuel injected. · FP and HP Volkswagen Rabbit descriptions updated to clarify Cabriolet body style inclusion. · EP, FP, HP: rear drum-to-disc brake conversion clarified; rotors solid, diameter limited to largest front rotor permitted. · EP Ford Mustang 94-98 fuel injected throttle body inside diameter set to 60. · FP Volkswagen Scirocco: remove two weight tiers at 1733 and 1803 lbs, two engine options, and 13-inch wheel option; allow 15-inch wheels. · T3 and T4 Mazda MX-5 Miata add permitted gearset kit PT#0000-02-6100 to Notes. · T4 MX-5 Miata 19-24 and 16-18, T3 MX-5 16-18 and Global Cup ND1/ND: discontinued DG Motorsports hardtop part #0000-07-5901 removed from permitted list. · HP Plymouth Arrow gains 4 or 5 speed transmission option specification. · Appendix G.2.3 clarifies rim width and diameter are absolute maximums; wording corrected from 'is' to 'are'. · EP, FP, HP throttle body inside dimensions and butterfly now allow +/-.25mm tolerance from stock.showhide
AS 2016+ Camaro Spec Line Full Prep #39646otheraddedAS Camaro 16+ Spec Line: 1LE front splitter kit permitted, belt tensioner and motor mount parts allowed, spark plug position defined.
AS Consideration of Pirelli P Zero Trofeo Track for AS Competition #40495tyres & wheelsadded · tyres & wheelsAS class adds Pirelli P Zero Trofeo Track as permitted tyre option for competition.
T4 02-06 R53 Mini Cooper Hotchkins Rear Camber Arms #40677suspension & brakes
AS Change in 9.1.6.D.4.d.5 in Suspension Mounting Points #40094suspension & brakesfaster · suspension & brakesAS class rear trailing arms no longer required to maintain stock length, only to locate rear axle.
AS Re-Add 4.6L 4v 96-04 Mustang Cobra #40239cars addedaddedAS Ford Mustang GT 4.6L 4-valve regains allowance, minimum weight 3200 lbs.
AS Errors and Omissions #40532weightslower · weightAS Ford Mustang Coupe GT 05-14 Gen3 Coyote minimum weight increases from 3100 to 3400 lbs.
FP Mini Cooper Compression Ratio #40517enginefaster · engineHP Mini Cooper 02-06 compression ratio increases from 10.6 to 11.0:1.
FP 1996-2000 Honda Civic (CX, DX, VP, LX) with Engine Code D16Y7 #40322cars addedadded1996-2000 Honda Civic CX/DX/LX with D16Y7 engine newly classified in HP.
FP 1275 Midget/Sprit Alternate intake manifold E/O #40370inductionadded · inductionHP 1275 Midget/Sprite alternate intake manifold from MG-B now permitted; balance tube shortening and flange modification allowed.
FP HP Honda Civic (92-95) #40464weight -70 lbsfaster · weightHP Honda Civic DX/LX 92–95 wheels 13x7 to 15x7, weight 2420 to 2350 lbs.
STL Spec Line Clean Up #40344cars addedremoved · cars addedSTL removes Mazda MX-5 Cup entirely; renames Spec MX5 Challenge to Spec MX5; renames Global Cup to MX-5 Cup (16-18); removes Global Cup (2019).
AS Clarification for LM7 Holley Carburetor #40167wordingwordingAS GM LM7 5.3L must use full prep Holley carburetor as described in 9.1.6.D.c.1, not specifically 4776.
STL Calculating Weight #40224wordingwordingSTL, STU weight calculation procedure clarified: positive percentages added first, negative subtracted second, then fixed weights applied.
FP Miata track width - errors and omissions #39976aerofaster · aeroEP Mazda MX-5 94-97 front track widens to 1516 mm, rear to 1534 mm.
FP GCR Spec Line Correction #39977wordingwordingFP Volkswagen Jetta 82-84 carburation option 2 comma removed; all five models' carb specs clarified or confirmed.
FP CGR Spec Line Weight Correction #39978wordingwordingFP Spec Line Volkswagen Rabbit and Scirocco 1789cc base weight corrected to 1803 lbs.
FP Triumph GT6 Spec Change. #40098inductionfaster · inductionEP Triumph GT6 auto-type drivetrain choke size increases from 44mm to 45mm.
FP Request to Classify BMW E21 320i #40110cars addedaddedBMW E21 320i/is (80–83) newly classified in HP Spec Lines effective 2026-05-01.
FP BMW 318is 84-85 engine displacement correction #40116wordingwordingHP BMW 318is 84-85 displacement corrected to 1767 cc, 89.0 x 71.0 mm bore and stroke.
T4 2003 Honda Civic Si Classification #39999cars added
AS Header Information Update for EFI Engine Build Sheets #39886engineadded · engineAS EFI engine build sheets add dry sump, header, camshaft, and timing chain tensioner options for LS, LT1, Ford, and Mopar engines.
AS Errors and Omissions #39933otherfasterAS LT1 Camaro engine build sheet added with full specs; LT1 weight 3200 lbs, GTO tire to 275, Mustang weight to 3525 lbs, oil catch tanks now required.
AS Re-Organization of AS Spec lines for 2026 #39887wordingwordingAS Spec Lines reorganized for 2026; detailed chassis, engine, weight, wheelbase, tire and brake specifications moved to main rules and engine build sheets.
FP Correct Valve Sizes on FP Fiat x19 1300 and 1500 #39850otherotherFP Fiat X-1/9 1300 and 1500 intake and exhaust valve sizes corrected to 36.3/(1.43) and 31.2-33.3/(1.23-1.31).
FP Dual Carburetor Adjustments #39851inductionfaster · inductionFP Fiat X-1/9 & Bertone dual carburetors choke size increases from 28mm to 30mm on intake runner manifold.
T4 ND MX-5 Spec Line Rewrite Request #39802weight -100 lbs
AS Edelbrock manifold (& timing kit) to Chevy LS Spec Lines Request #39055cars addedaddedAS GM LM7 5.3L gains Edelbrock 71187 intake manifold, MSD 6014 ignition box, Holly 4776 carb option under full prep spec line.
FP Request Toyota 5E Series Engines #38208otheraddedFP adds Toyota 5E 1497cc DOHC engine, 1900 lbs, 23mm restrictor, SIR fuel induction.
FP Request for Toyota 4E Series Engines #38209cars addedaddedFP class adds Toyota 4E DOHC 1331 cc engine, 1900 lbs minimum weight, unrestricted fuel induction.
FP Dual Carbs for the Fiat X1/9 #39593enginefaster · engineFP Fiat X1/9 fuel injection carburetors simplified to one 36 or 40 DCNF option; exhaust valve enlarged to 33.0/1.30.
T4 Allow Alt Bushing Material in Toe Links #39607suspension & brakesadded · suspension & brakesT2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously only spherical bearings permitted.
AS Restrictor Plate Change for Gen 2 Ford Coyote Engine #39501inductionslower · inductionAS Ford Mustang and Mercury Capri with Restricted Prep engines get 61 mm restrictor, down from 64 mm.
STL Weight adjustment for STL #39579weightslower · weightSTL minimum weights increase across all engine sizes, 1300cc to 1850cc up to 195–250 lbs.
T4 Alternate Placement of Fuse Panel and Electronics Request #39370otheraddedT2, T3, T4 now allow under-dash electronics relocation for access after roll cage installation.
T4 Clarify T4 Brake Rotor Allowance #39503wordingwordingT4 Performance clarified: 1-piece alternative rotors permitted only at sizes listed in spec line; alternate brake kits may use matching 1-piece rotors.
AS 1994 Mustang Spec Line Request #39104engineadded · engineAS Ford Mustang GT 94-04 Restricted Prep Engine now permits Ford Motorsport M-6250-F303 camshaft.
FP TR2 Notes E&O #39180wordingwordingEP Triumph TR2–TR4A may use 5-speed gearbox without overdrive; Weber carburetors and weight reference deleted.
FP Balance of Power #39187induction +50 lbsslower · inductionEP BMW Z3 2.5L and other models get smaller restrictors, 50mm to 55mm, and Z3 2.5L weight rises 50 to 78 lbs.
FP Competition Adjustment Request #39259weight -80 lbsfaster · weightFP Lancia Scorpion minimum weight cut to 1950 lbs from 2030 lbs.
FP Factory Roll Bar Removal on VW Convertible #39268wordingwordingFP VW Rabbit Convertible no longer required to remove factory roll bar.
FP FP Parity Request #39325weight +50 lbsslower · weightFP Acura Integra and Honda Civic models gain 50–79 lbs minimum weight; Mazda Miata and Mercury Capri compression ratio to 11.0:1 and valve lift to .425".
FP Adjust former-GTL Honda's with B/D-Series Engines #39374weightslower · weightFP Honda D15, D16, B16A, B18 engines gain 105–120 lbs minimum weight across seven configurations.
FP HP Volvo 142 spec omission #38994engineslower · engineHP Volvo 142 P-1800 engine gains compression ratio limit 12.0:1 and valve lift limit .425 inch.
FP HP Mini DOHC 1.6 #38996engineslower · engineHP Mini DOHC 1.6 valve lift limit drops to .390" from .450".
FP 83-88 FP Scirocco Spec Line Creation #38997cars addedaddedFP Scirocco 83–88 classified Prep Level 1: 1733–1803 lbs, 1715–1780 cc, iron block, aluminium head, carburetted or fuel injected.
FP Add to Rabbit description #39019wordingwordingFP and HP Volkswagen Rabbit descriptions updated to clarify Cabriolet body style inclusion.
FP Clean-up 9.1.5.E.7e #39025otherotherEP, FP, HP: rear drum-to-disc brake conversion clarified; rotors solid, diameter limited to largest front rotor permitted.
FP Add TB size to Ford Mustang (94-98) Spec Line #39130inductionadded · inductionEP Ford Mustang 94-98 fuel injected throttle body inside diameter set to 60.
FP Correct Existing VW Scirocco Spec Line #39140cars addedremoved · cars addedFP Volkswagen Scirocco: remove two weight tiers at 1733 and 1803 lbs, two engine options, and 13-inch wheel option; allow 15-inch wheels.
T4 ND Spec Lines Wrong PT#'s #39170removedremovedT4 MX-5 Miata 19-24 and 16-18, T3 MX-5 16-18 and Global Cup ND1/ND: discontinued DG Motorsports hardtop part #0000-07-5901 removed from permitted list.
FP HP Plymouth Arrow spec omission #38995cars addedaddedHP Plymouth Arrow gains 4 or 5 speed transmission option specification.
FP Add Wheel Diameter to Appendix G #39008wordingwordingAppendix G.2.3 clarifies rim width and diameter are absolute maximums; wording corrected from 'is' to 'are'.
FP Add TB ID tolerance to general Prod rules #39009wordingaddedEP, FP, HP throttle body inside dimensions and butterfly now allow +/-.25mm tolerance from stock.
2:32.065Jose Osiris Pena · fastest of 14 · top 5 within 3.4s+2.002s (+1.33%)
2:32.127Jose Osiris Pena · fastest of 13 · top 5 within 2.4s+1.882s (+1.25%)
132.2Jon Sewell-2.1 mph (-1.5%)
2:26.792Andrew McDermid · fastest of 11 · top 5 within 3.9s+0.214s (+0.15%)
2:29.232Gregory Eaton · fastest of 10 · top 5 within 4.0s+2.803s (+1.91%)
151.5Andrew McDermid+1.9 mph (+1.3%)
-2.895squal -5.273s
98.1%qual 96.5%
2:32.956Matt Spicuzzi · fastest of 10 · top 5 within 3.8s-1.474s (-0.95%)
2:32.633Alex Lozano · fastest of 10 · top 5 within 4.3s-1.575s (-1.02%)
133.7Alex Lozano+4.4 mph (+3.4%)
+0.506squal +0.891s
100.3%qual 100.6%
2:32.395David Strittmatter · fastest of 20 · top 5 within 2.9s+0.068s (+0.04%)
2:34.271Chris Bovis · fastest of 19 · top 5 within 1.8s+1.025s (+0.67%)
132.4David Strittmatter-1.1 mph (-0.8%)
+2.144squal +0.330s
101.4%qual 100.2%
60 rule changes (STL: 3, AS: 11, T4: 29, FP: 17)14 weight · 10 cars added · 6 induction · 5 engine · 4 tyres & wheels · 1 aero · 1 removed · 10 wording · 9 other · Lotus Evora GT4 minimum weight drops to 2700 lbs; Elise Cup R to 2250 lbs; Elise SC and Exige SC to 2450–2550 lbs. · T2, T3, T4 spec table header changed from T2 to ET. · AS Ford Mustang GT 5.0 2018- minimum weight reduced to 3525 lbs. · EP BMW Z4 03-05 gains 52mm flat plate intake restrictor. · EP Fiat 124 Spider Competition 1600 and 2000 minimum weight drops 50 lbs to 2000; carburetors now allow 36mm chokes instead of 34mm. · AS Ford Mustang GT 05-14 Restricted Prep Engine gains additional gear ratio option: 3.66, 2.43, 1.69, 1.32, 1.00, .65. · HP Fiat X-1/9 and Bertone 1500 minimum weights reduced to 1740 lbs, 1784 lbs, 1827 lbs; 1300 models to 1600, 1640, 1680 lbs; additional 1300 and 1500 specs to 2010, 1900 lbs. · AS Ford Mustang GT 5.0L 15-17 flat plate restrictor reduces from 67mm to 64mm. · AS LS1/LS6 intakes added for 5.3L truck engine: part numbers 12561269 and 88894095. · STL Mazda MX5 Challenge minimum weight now references GCR 9.1.7.1; mandatory component spec list removed, alternative tires only allowed. · AS Flotek head value seat cutting dimensions figure updated for consistency. · AS class notes cleaned: fuel cell and ECM specifications removed from multiple Camaro, Firebird, Challenger and Mustang variants. · Chevrolet Spark 16-22 classified in HP Pre at 1850 lbs base, 1896 lbs modified, 1943 lbs. · HP Ford Festiva 88-93 minimum weight lowered to 1600 lbs, competition weight to 1640, prepared weight to 1680; compression ratio raised to 11.0:1. · AS removes 'Any ECM maybe used' note from five Cadillac and Chevrolet/Pontiac V8 Restricted Prep models. · EP BMW Z3 2.5L, Z3 2.8L, 328i E36/E46, 325i E36/E46 intake restrictors reduced 4mm each, to 52–58mm. · FP Acura Integra and Honda Civic models restricted from 55mm to 51mm intake; Del Sol VTEC weight raised to 2290, 2347, 2405 lbs. · EP, FP, HP may use any interior or exterior mirror meeting rule 9.3.36. · EP Honda S2000 1997cc minimum weight drops 75 lbs to 2375; 2157cc drops 60 lbs to 2450. · EP Mazda MX-5 Miata 99-05 minimum weight reduced to 2100 lbs, 2153 lbs with power, 2205 lbs modified. · FP Volkswagen Jetta Mark IV 4dr FWD added to GTL-FP Cars classification with 98.2 in wheelbase. · FP adds optional induction chokes as alternative to SIR, same size as listed restrictor. · EP BMW models now require flat plate intake restrictors: Z3 2.5L 52mm, Z3 2.8L 55mm, 328i E36 58mm, 328i/ci E46 58mm, 325i E46 56mm, 325i E36 56mm, 325is M-Technic 56mm. · Ford SCCA Club Spec Mustang added to T3 at 3350 lbs; Mazda SCCA Club Spec MX-5 added to T4 at 2500 lbs. · AS Ford Mustang and Cobra Coyote engine restrictor increases to 80mm from 67mm or 64mm. · AS Mustang GT 05-14 Restricted loses 300 lbs engine; 15-17 and 2018+ models lose 61mm and 60mm restrictors respectively. · AS class: multiple American muscle cars gain additional allowed gear ratio options across model years and prep levels. · AS LS-engine cars gain ECU freedom: CTS-V, Camaro, Firebird (70–02) and Camaro SS may use any ECM. · EP BMW 325i/is E30 84-91 weight reduced to 2150 lbs base, 2204 lbs with turbo, 2258 lbs supercharged. · FP Sprite and Midget 1275cc and 1500cc bore, stroke, displacement, and valve specifications corrected to factory dimensions. · F Production now permits GT-Lite cars meeting Appendix N specs to compete, governed by Appendix N not PCS 9.1.5. · T2, T3, T4: nine, nine, and thirty-seven expired spec lines removed effective 2025-01-01. · STL STU Mazda Miata alternate front hubs Mazda Motorsports Development Part #0000-04-5HUB-S1 approved. · T2, T3 Mustang spec lines remove redundant driveshaft allowance notes across six model year ranges. · T2, T3, T4 fuel cell installations may omit charcoal canisters, emissions valves, and sensors. · T2, T3, T4 brake specifications clarified: 2-piece rotors allowed in T2 within 5% OE diameter, T3 within 2% OEM diameter. · T2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors. · Porsche Spec Boxster moves to T4, minimum weight 2750 lbs, ineligible for Runoffs until 3 Super Tour events. · T4 BMW 320i Spec Line: Turner Motorsports intercooler #024703TMS02 now allowed. · 2005 Cadillac CTS 3.6L 6-speed manual classified in T3 Spec. · HP 1275 Spridget compression ratio raised to 12.0:1; 1098cc also raised to 12.0:1.showhide
STL Lotus Weight Reduction #38772weight -50 lbsfaster · weightLotus Evora GT4 minimum weight drops to 2700 lbs; Elise Cup R to 2250 lbs; Elise SC and Exige SC to 2450–2550 lbs.
T4 Incorrect Touring Heading #38451wordingwordingT2, T3, T4 spec table header changed from T2 to ET.
AS RE: Previous Letter 37695 Update #38245weight -75 lbsfaster · weightAS Ford Mustang GT 5.0 2018- minimum weight reduced to 3525 lbs.
FP BMW Z4 update #38490inductionslower · inductionEP BMW Z4 03-05 gains 52mm flat plate intake restrictor.
FP EP Fiat 124 Spider Competition Adjustment Request #38498weight -50 lbsfaster · weightEP Fiat 124 Spider Competition 1600 and 2000 minimum weight drops 50 lbs to 2000; carburetors now allow 36mm chokes instead of 34mm.
AS Errors and Omission #38055inductionslower · inductionAS Ford Mustang GT 5.0L 15-17 flat plate restrictor reduces from 67mm to 64mm.
AS Request to Add LS1/LS6 Intakes for 5.3L Truck Engine EnO #38197cars addedaddedAS LS1/LS6 intakes added for 5.3L truck engine: part numbers 12561269 and 88894095.
STL E&O: SMX Allowance in STL #37945wordingunclearSTL Mazda MX5 Challenge minimum weight now references GCR 9.1.7.1; mandatory component spec list removed, alternative tires only allowed.
T4 Correct Ring and Pinion Ratio to T3, Sorry I Mean T4 3.7 V6 Stang #38041wording
AS Flotek Head Plunge Cut Inconsistencies #37502wordingwordingAS Flotek head value seat cutting dimensions figure updated for consistency.
AS Notes clean up #37693wordingwordingAS class notes cleaned: fuel cell and ECM specifications removed from multiple Camaro, Firebird, Challenger and Mustang variants.
FP Request for Classification of Chevrolet Spark #37755cars addedaddedChevrolet Spark 16-22 classified in HP Pre at 1850 lbs base, 1896 lbs modified, 1943 lbs.
FP Request to Lower Ford Festiva Minimum Weight to 1600 LBS #37939weight -100 lbsfaster · weightHP Ford Festiva 88-93 minimum weight lowered to 1600 lbs, competition weight to 1640, prepared weight to 1680; compression ratio raised to 11.0:1.
AS Race memo #37902wordingwordingAS removes 'Any ECM maybe used' note from five Cadillac and Chevrolet/Pontiac V8 Restricted Prep models.
FP Request Competition Adjustment to BMW Z3 2.5L #37120inductionslower · inductionEP BMW Z3 2.5L, Z3 2.8L, 328i E36/E46, 325i E36/E46 intake restrictors reduced 4mm each, to 52–58mm.
FP FP Class Adjustments #37458inductionslower · inductionFP Acura Integra and Honda Civic models restricted from 55mm to 51mm intake; Del Sol VTEC weight raised to 2290, 2347, 2405 lbs.
FP Interpretation of Production Rules on Mirrors #37235wordingaddedEP, FP, HP may use any interior or exterior mirror meeting rule 9.3.36.
FP Weight Reduction for Honda S2000 #37466weightfaster · weightEP Honda S2000 1997cc minimum weight drops 75 lbs to 2375; 2157cc drops 60 lbs to 2450.
FP Errors & Omissions #37648cars addedaddedFP Volkswagen Jetta Mark IV 4dr FWD added to GTL-FP Cars classification with 98.2 in wheelbase.
FP GTL/FP consolidation 2025 Rules #37659inductionadded · inductionFP adds optional induction chokes as alternative to SIR, same size as listed restrictor.
FP Effective date for Jan 2025 GCR updates #37654inductionslower · inductionEP BMW models now require flat plate intake restrictors: Z3 2.5L 52mm, Z3 2.8L 55mm, 328i E36 58mm, 328i/ci E46 58mm, 325i E46 56mm, 325i E36 56mm, 325is M-Technic 56mm.
T4 Request to Classify Club Spec in Appropriate Touring Classes #37523cars addedaddedFord SCCA Club Spec Mustang added to T3 at 3350 lbs; Mazda SCCA Club Spec MX-5 added to T4 at 2500 lbs.
AS Increase Coyote Engine Restrictor to 80mm #36177enginefaster · engineAS Ford Mustang and Cobra Coyote engine restrictor increases to 80mm from 67mm or 64mm.
AS Performance Pack for 2015+ Mustang #36867enginefaster · engineAS Mustang GT 05-14 Restricted loses 300 lbs engine; 15-17 and 2018+ models lose 61mm and 60mm restrictors respectively.
AS Gear Ratios #37131otheraddedAS class: multiple American muscle cars gain additional allowed gear ratio options across model years and prep levels.
AS ECU specs for LS engine #37208engineadded · engineAS LS-engine cars gain ECU freedom: CTS-V, Camaro, Firebird (70–02) and Camaro SS may use any ECM.
FP Request to Reduce Weight of BMW 325i/is E30 (84-91) Spec Line #37119weight -50 lbsfaster · weightEP BMW 325i/is E30 84-91 weight reduced to 2150 lbs base, 2204 lbs with turbo, 2258 lbs supercharged.
FP Fix Error in Spridget Spec Line #37437wordingwordingFP Sprite and Midget 1275cc and 1500cc bore, stroke, displacement, and valve specifications corrected to factory dimensions.
FP Create ruleset that allows GTL cars to run in FP #37485cars addedaddedF Production now permits GT-Lite cars meeting Appendix N specs to compete, governed by Appendix N not PCS 9.1.5.
T4 Remove spec lines that have expired #37269removedremovedT2, T3, T4: nine, nine, and thirty-seven expired spec lines removed effective 2025-01-01.
STL Request to Remove Miata Hubs from General category #37138cars addedaddedSTL STU Mazda Miata alternate front hubs Mazda Motorsports Development Part #0000-04-5HUB-S1 approved.
T4 Redundant Verbiage Regarding Mustang Spec Lines for Driveshaft #36484wordingwordingT2, T3 Mustang spec lines remove redundant driveshaft allowance notes across six model year ranges.
T4 R53 Mini Cooper S Weight Reduction Request #36612weight
T4 Move Spec Boxster to T4 #37158cars addedaddedPorsche Spec Boxster moves to T4, minimum weight 2750 lbs, ineligible for Runoffs until 3 Super Tour events.
2:30.063Joe Moser · fastest of 18 · top 5 within 3.7s-1.357s (-0.90%)
2:30.245Joe Moser · fastest of 16 · top 5 within 4.2s-1.870s (-1.23%)
134.3Joe Moser+1.3 mph (+1.0%)
2:26.578Gregory Eaton · fastest of 18 · top 5 within 2.6s-0.467s (-0.32%)
2:26.429Gregory Eaton · fastest of 18 · top 5 within 2.5s-1.239s (-0.84%)
149.6Gregory Eaton+0.4 mph (+0.3%)
-3.816squal -3.485s
97.5%qual 97.7%
2:34.430Matt Spicuzzi · fastest of 15 · top 5 within 1.8s-2.973s (-1.89%)
2:34.208Alex Lozano · fastest of 14 · top 5 within 2.2s-3.673s (-2.33%)
129.3Alex Lozano-0.9 mph (-0.7%)
+3.963squal +4.367s
102.6%qual 102.9%
2:32.327Cliff Ira · fastest of 26 · top 5 within 2.1s+0.913s (+0.60%)
2:33.246Kevin Ruck · fastest of 24 · top 5 within 1.4s-0.787s (-0.51%)
133.5David Strittmatter+0.3 mph (+0.2%)
+3.001squal +2.264s
102.0%qual 101.5%
64 rule changes (STL: 4, AS: 11, T4: 28, FP: 21)18 weight · 14 cars added · 5 engine · 5 suspension & brakes · 3 aero · 3 induction · 2 removed · 1 tyres & wheels · 6 wording · 7 other · FP Honda CRX/CRX Si 84-87 block material changes from iron to aluminium. · AS Mustang GT 05-14 Restricted Prep and 2018- gain alternate transmission ratio options. · HP Volkswagen Golf and Jetta 85-92 track correction: front 1537 mm (60.5 in.), rear 1529 mm (60.2 in.). · T2 Mustang GT 5.0L 15-17 and 2018- now permit Track/Performance Package parts; T3 V6 15-17 clarified to allow Track/Performance package. · T2-T4 Ford Mustangs: remove 25 lb penalty for non-OEM driveshaft, clarify alternate driveshaft allowance. · Audi S4 (2000–2002) classified in T3 with 2671cc, 3400 lbs minimum weight, 38mm restrictor, allowing 800lb springs and intercooler. · AS adds 2018-23 Ford Mustang GT 5.0L at 3600 lbs, 275 tire, 60mm restrictor, optional Brembo front brakes. · Nissan 300ZX 84–89 added to EP, 2550–2678 lbs, 2960 cc SOHC, fuel injection, 12.0:1 compression, 0.500" valve lift limit. · Mazda RX-7 92-97 added to EP Prep as Level 2 rotary 13B 6-port, 2200–2310 lbs, carb or fuel injection, 42 mm choke. · EP Mazda RX-8 (04-11) alternate spec line removed; single spec line retained. · AS Chevrolet Camaro 1LE (2016-) added with 3600 lbs minimum weight, 275 tires, 60mm restrictor, 345/338mm brakes. · AS Chevrolet/Pontiac Camaro & Firebird 82–92 5.7L LS1 classified: 3200 lbs, 13.1×1.27 disc brakes, 17 in max wheel, 65 mm restrictor, SLP intake lid permitted. · AS Chevrolet Camaro, Firebird, and Ford Mustang now permit Flo Tek cylinder heads in multiple generations. · FP Honda CRX 84-87 plastic front header nose panel, rocker skirts, door caps can now be replica alternate material stock appearance. · FP Acura Integra 90-01 and Honda Civic Del Sol VTEC, Civic Si 99-00 require 55mm flat plate intake restrictor. · T3 and T4 Mazda RX-8 may remove or disable factory oil injection system. · T2, T3, T4 driveshafts may use carbon fiber, aluminum, or steel; two-piece replaced with one-piece; non-OEM adds 25 lbs. · AS Camaro, Firebird 93-02 and GTO 04-06 add approved LS1 connecting rod part numbers to Notes. · AS Cadillac CTS-V, Chevy Camaro SS V8, Dodge Challenger, Ford Mustang GT 5.0L, Pontiac GTO allowed 11" wheels until 3/1/25. · Chevrolet Camaro, Pontiac Firebird 70–81 Full Prep classified in AS at 3400–3600 lbs with 108.0 wheelbase, specific head castings, and suspension modifications permitted. · AS class adds fuel cell location notes to multiple Cadillac, Chevrolet, Dodge and Ford models: cells within 24 inches of standard tank. · Chevrolet Camaro 6th gen Full Prep added to AS class at 3400 lbs base or 3600 lbs with built engine. · AS class: Ford Mustang GT 05-14 Restricted prep added; Cadillac CTS-V 04-07 to 3450 lbs; Camaro/Firebird variants reconfigured with weight and notes changes; Dodge Challenger 08-20 restrictor 76mm to 80mm; Ford Mustang variants updated wei… · HP removes four redundant VW spec lines: Rabbit Cabriolet 1780, Scirocco 1588, Scirocco 1780 8-valve 83-88, Scirocco 1588. · FP Mazda Protégé ES (01-03) renamed to Mazda Protégé ES/5 (01-03). · T2, T3, T4 Spec Lines remove wheelbase requirement, add Required Restrictor specification. · T2 and T3 Nissan 370Z front brake rotors increase to 355×32 mm, rears to 350×20 mm. · HP Honda Civic 1.5 1988-91 minimum weight drops 70 lbs to 2175; also 2-speed and 3-speed minimums cut 72 and 73 lbs. · STL and STU now permit electric power steering pumps, OEM electric-assisted steering, or column-mounted electric steering assist systems. · STL normally aspirated minimum weights reduced: 1900cc to 2540 lbs, 1950cc to 2583 lbs, 2000cc to 2625 lbs; short-wheelbase FWD adds 1.25%; Honda B16/B17/B18C1 throttle to 51mm, B18C Type R and Mazda MZR to 50mm. · STL Mazda 12A: 5th and 6th intake port actuators and valves may no longer be removed or disabled. · T2, T3, T4 battery replacement no longer allows alternate manufacturer batteries within 10% OEM weight. · T4 now allows C-Spec touring cars to compete, in addition to existing B-Spec eligibility. · T2, T3, T4 spec lines expire 12/31/24; submit to appeal or cars are removed from class. · EP BMW Z3 2.5L minimum weight increased to 2500 lbs, 2563 lbs with power adder, 2625 lbs with two power adders. · FP Honda throttle body inside diameters corrected across seven models: Civic 1.5 to 42", Civic Si to 55", CRX 1.5 to 42", CRX 84-87 to 33/42", CRX Si 88-91 to 55". · EP Mazda MX-5 1.8L (90-97) minimum weight cut to 2150 lbs; (94-97) variants to 2000, 2050, 2100 lbs. · EP Triumph GT6 dual 1.75-inch carburetors weight rises to 1940 lbs; triple Weber 40 DCOE option added at 1990 lbs. · EP Honda S2000 fuel injected throttle body inside diameter increases from 62mm to 64mm. · EP Triumph TR8 dry sump allowance moved from Carburetor line to Notes. · EP Porsche 944/924S 2.5L and 2.7L minimum weights corrected: 2479cc to 2306–2363 lbs, 2681cc to 2358–2415 lbs. · STL 79-85 RX7 12A now allows auto-type 2 bbl carburetor with 42mm choke on dual-y manifold, not just stock Nikki. · T3 Nissan 370Z now includes model years 2009–2022 with Nismo editions. · EP Porsche 944/924S combines 2.5L and 2.7L variants (83-89), raises weight to 2250–2415 lbs, allows 2681cc displacement. · FP Toyota Corolla 2TC loses 43 lbs to 1810; HP Corolla loses 50–52 lbs to 1910–2006. · EP Triumph GT6 minimum weight drops to 1800 lbs.showhide
FP Errors/emissions Honda Civic/CRX #36700enginefaster · engineFP Honda CRX/CRX Si 84-87 block material changes from iron to aluminium.
AS Mustang transmission ratios #36662otheraddedAS Mustang GT 05-14 Restricted Prep and 2018- gain alternate transmission ratio options.
FP Errant entry in HP production line item #36231wordingwordingHP Volkswagen Golf and Jetta 85-92 track correction: front 1537 mm (60.5 in.), rear 1529 mm (60.2 in.).
T4 B8/8.5 Audi S4 T3 and T2 #36195cars addedaddedAudi S4 (2000–2002) classified in T3 with 2671cc, 3400 lbs minimum weight, 38mm restrictor, allowing 800lb springs and intercooler.
AS Request for Classification of 2018-2023 mustang In #35764cars addedaddedAS adds 2018-23 Ford Mustang GT 5.0L at 3600 lbs, 275 tire, 60mm restrictor, optional Brembo front brakes.
FP NIssan 300ZX Z31 to EP #35830cars addedaddedNissan 300ZX 84–89 added to EP, 2550–2678 lbs, 2960 cc SOHC, fuel injection, 12.0:1 compression, 0.500" valve lift limit.
FP RX7 1993 and Up Request In EP Spec Lines, classify #36031cars addedaddedMazda RX-7 92-97 added to EP Prep as Level 2 rotary 13B 6-port, 2200–2310 lbs, carb or fuel injection, 42 mm choke.
FP Clean-up Multiple EP RX-8 Spec Lines In EP #36156cars addedremoved · cars addedEP Mazda RX-8 (04-11) alternate spec line removed; single spec line retained.
T4 Allow OEM Front Spoiler 06-08 Miata in T4 #35941aero
T4 R53 Mini Cooper S spec line request In #36056suspension & brakes
AS 6th gen Camaro limited prep #35733cars addedaddedAS Chevrolet Camaro 1LE (2016-) added with 3600 lbs minimum weight, 275 tires, 60mm restrictor, 345/338mm brakes.
AS Chevrolet/Pontiac Camaro & Firebird (82-92) 5.7L V8 LS1 Alum BLK #35825cars addedaddedAS Chevrolet/Pontiac Camaro & Firebird 82–92 5.7L LS1 classified: 3200 lbs, 13.1×1.27 disc brakes, 17 in max wheel, 65 mm restrictor, SLP intake lid permitted.
AS Full Prep Head #35891engineadded · engineAS Chevrolet Camaro, Firebird, and Ford Mustang now permit Flo Tek cylinder heads in multiple generations.
FP Request to Replace CRX Plastic Panels #35876cars addedaddedFP Honda CRX 84-87 plastic front header nose panel, rocker skirts, door caps can now be replica alternate material stock appearance.
FP FP data and parity #35896inductionadded · inductionFP Acura Integra 90-01 and Honda Civic Del Sol VTEC, Civic Si 99-00 require 55mm flat plate intake restrictor.
T4 Allow T4 and T3 RX8 to Disable/Remove Factory Oil Inj. #35761engineadded · engineT3 and T4 Mazda RX-8 may remove or disable factory oil injection system.
T4 2023 ND2 Miata Classification and Allowances #35837weight
T4 Errors and Omissions for 06-09 VW Rabbit Rotor #35851suspension & brakes
T4 Driveshafts #35916weightslower · weightT2, T3, T4 driveshafts may use carbon fiber, aluminum, or steel; two-piece replaced with one-piece; non-OEM adds 25 lbs.
T4 GCR ERROR - letter not properly applied to GCR #35999weight
AS Restricted Prep Aftermarket Parts Request #35682otheraddedAS Camaro, Firebird 93-02 and GTO 04-06 add approved LS1 connecting rod part numbers to Notes.
AS Allowance of 11 #35824tyres & wheelsfaster · tyres & wheelsAS Cadillac CTS-V, Chevy Camaro SS V8, Dodge Challenger, Ford Mustang GT 5.0L, Pontiac GTO allowed 11" wheels until 3/1/25.
AS Request to Classify 1970-1981 Camaro and Firebird in AS #33659cars addedaddedChevrolet Camaro, Pontiac Firebird 70–81 Full Prep classified in AS at 3400–3600 lbs with 108.0 wheelbase, specific head castings, and suspension modifications permitted.
AS Fuel Cell 12 #34194otheraddedAS class adds fuel cell location notes to multiple Cadillac, Chevrolet, Dodge and Ford models: cells within 24 inches of standard tank.
AS Please Classify the 6th Gen Into AS. #35448cars addedaddedChevrolet Camaro 6th gen Full Prep added to AS class at 3400 lbs base or 3600 lbs with built engine.
AS spec lines #35713otherunclearAS class: Ford Mustang GT 05-14 Restricted prep added; Cadillac CTS-V 04-07 to 3450 lbs; Camaro/Firebird variants reconfigured with weight and notes changes; Dodge Challenger 08-20 restrictor 76mm to 80mm; Ford Mustang variants updated wei…
T4 Allow any 400lb rear spring in the RX8 #35433suspension & brakes
T4 370Z Brake Rotor Size Correction #35487suspension & brakessuspension & brakesT2 and T3 Nissan 370Z front brake rotors increase to 355×32 mm, rears to 350×20 mm.
FP Update 1988-1991 Civic to Match 1988-1991 CRX #35399weightfaster · weightHP Honda Civic 1.5 1988-91 minimum weight drops 70 lbs to 2175; also 2-speed and 3-speed minimums cut 72 and 73 lbs.
STL ST Electric-Assisted Steering Systems #35066aeroadded · aeroSTL and STU now permit electric power steering pumps, OEM electric-assisted steering, or column-mounted electric steering assist systems.
STL BOP Adjustments #35112weightfaster · weightSTL normally aspirated minimum weights reduced: 1900cc to 2540 lbs, 1950cc to 2583 lbs, 2000cc to 2625 lbs; short-wheelbase FWD adds 1.25%; Honda B16/B17/B18C1 throttle to 51mm, B18C Type R and Mazda MZR to 50mm.
STL Mazda 12A #35320engineremoved · engineSTL Mazda 12A: 5th and 6th intake port actuators and valves may no longer be removed or disabled.
T4 More Car Lightening Stuff #35319wordingremovedT2, T3, T4 battery replacement no longer allows alternate manufacturer batteries within 10% OEM weight.
T4 Inclusion of B-C spec cars in T4 #35374cars addedaddedT4 now allows C-Spec touring cars to compete, in addition to existing B-Spec eligibility.
T4 T2-T4 Set expiration dates on spec lines #35378wordingremovedT2, T3, T4 spec lines expire 12/31/24; submit to appeal or cars are removed from class.
FP Request to Review Z3 2.5 Spec Line #35073weight +50 lbsslower · weightEP BMW Z3 2.5L minimum weight increased to 2500 lbs, 2563 lbs with power adder, 2625 lbs with two power adders.
FP Corrections to Honda Spec Lines in FP #35250wordingunclearFP Honda throttle body inside diameters corrected across seven models: Civic 1.5 to 42", Civic Si to 55", CRX 1.5 to 42", CRX 84-87 to 33/42", CRX Si 88-91 to 55".
FP Miata Alternate Head #35253weight -50 lbsfaster · weightEP Mazda MX-5 1.8L (90-97) minimum weight cut to 2150 lbs; (94-97) variants to 2000, 2050, 2100 lbs.
FP Honda S2000 throttle body #35272inductionfaster · inductionEP Honda S2000 fuel injected throttle body inside diameter increases from 62mm to 64mm.
FP Correction within Triumph TR8 Spec Line #35315wordingwordingEP Triumph TR8 dry sump allowance moved from Carburetor line to Notes.
FP Correction to EP 924S/944 Spec Line #35317weightweightEP Porsche 944/924S 2.5L and 2.7L minimum weights corrected: 2479cc to 2306–2363 lbs, 2681cc to 2358–2415 lbs.
STL Alternate Carburetor Request for 79-85 RX7 12a #35181engineadded · engineSTL 79-85 RX7 12A now allows auto-type 2 bbl carburetor with 42mm choke on dual-y manifold, not just stock Nikki.
T4 Mazda MX-5 ND1 Spec Line Request #34232weight +50 lbs
T4 BRZ/FRS/86 Spring Allowance #35038suspension & brakes
2:05.779Danny Steyn · fastest of 22 · top 5 within 3.4s+0.305s (+0.24%)
2:06.682Joe Moser · fastest of 20 · top 5 within 1.5s-1.150s (-0.90%)
131.8Danny Steyn+0.1 mph (+0.1%)
2:03.082Daniel Richardson · fastest of 11 · top 5 within 2.2s+0.920s (+0.75%)
2:04.120Gregory Eaton · fastest of 9 · top 5 within 3.0s-0.458s (-0.37%)
154.6James Jost+3.7 mph (+2.5%)
-2.562squal -2.697s
98.0%qual 97.9%
2:10.514Devin Anderson · fastest of 24 · top 5 within 0.5s+0.937s (+0.72%)
2:11.962Devin Anderson · fastest of 23 · top 5 within 0.1s-13.481s (-9.27%)
127.8Raymond Blethen+0.5 mph (+0.4%)
+5.280squal +4.735s
104.2%qual 103.8%
2:08.248Cliff Ira · fastest of 21 · top 5 within 1.0s+2.031s (+1.61%)
2:07.787Cliff Ira · fastest of 20 · top 5 within 0.8s-9.854s (-7.16%)
133.7Cliff Ira+1.1 mph (+0.9%)
+1.105squal +2.469s
100.9%qual 102.0%
32 rule changes (STL: 2, AS: 4, T4: 20, FP: 6)8 cars added · 5 weight · 4 suspension & brakes · 1 aero · 1 induction · 1 tyres & wheels · 8 wording · 4 other · AS crate motor part number specification clarified; both CT400 P/N-19370604 and 19370604 engine assemblies permitted for GM vehicles. · AS Ford Mustang GT 5.0L (15-17) Restricted maximum wheel diameter increases to 19.0 inches. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front upper control arms; SPC-66045 spec part removed. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 now allows alternate front brake calipers with adaptor brackets for component compatibility. · Mazda RX-8 T3 and T4 transmission and final drive pairing requirement removed; T4 gains Mazdaspeed radiator, spring kit, restrictor, spoiler, air dam. · T3 BMW 320i 14–15 gains aftermarket intercooler; T4 BMW 320i 14–15 loses it. · T3 and T2 Pontiac Solstice GXP 07-09 minimum ride height set to 3 inches. · FP and HP Sprite and Spitfire 1500 intake valve size corrected to 36.6 mm, removing prior decimal specifications. · HP Volkswagen Rabbit Cabriolet 1780 removed; Rabbit 1588 and 1715 reclassified with year and body-type clarifications. · Ford Fiesta HP model years change to 11-19; Chevrolet Sonic FP model years change to 12-19. · STL ITA and ITS RX7, and ITS/ITA/ITB/ITC 1985+ models clarified to require tires per 9.1.4.2. · Toyota Celica 78-80 classified FP Prep level 2, 2100–2205 lbs, 2190 cc SOHC four-cylinder, stock carburetion, 11.0:1 compression limit, .450" valve lift limit. · FP Mazda Protégé ES (01-03) renamed to Protégé ES/5 (01-03) to include P5 model variant. · T2 and T3 Mustang 11-14 may remove upper grille fog lights, replace with mesh or screen. · EP, FP, HP port matching limited to 1 inch depth from mating surface. · Spec MX5 in STL allows ACT clutch 0000-02-5004-G6, wheels 17x8, Toyo RR and RA1 235-40-17 tyres, or alternatives on 17x7 per rules. · T5 touring class added; T2-T5 cars may race one class up; T5 maximum tyre width 225 with minimum aspect ratio 45. · T2-T5 Touring front and rear suspension maximum negative camber clarified to 3.5 degrees.showhide
T4 Inclusion of similar car. (CLK 320) #34626other
AS Crate Motor Part Numbers #32944wordingwordingAS crate motor part number specification clarified; both CT400 P/N-19370604 and 19370604 engine assemblies permitted for GM vehicles.
AS Request wheel size change #33007tyres & wheelsfaster · tyres & wheelsAS Ford Mustang GT 5.0L (15-17) Restricted maximum wheel diameter increases to 19.0 inches.
AS Alternative Upper Front Control Arms for Dodge Challenger #33352wordingwordingAS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front upper control arms; SPC-66045 spec part removed.
AS Front Brake Caliper Adapters for Dodge Challenger #33353otherotherAS Dodge Challenger 5.7L/6.1L/6.4L V8 now allows alternate front brake calipers with adaptor brackets for component compatibility.
T4 Rules Clarification for Mazda RX8 Spec Line #34395wordingwordingMazda RX-8 T3 and T4 transmission and final drive pairing requirement removed; T4 gains Mazdaspeed radiator, spring kit, restrictor, spoiler, air dam.
T4 rule book corrections #34437otheraddedT3 BMW 320i 14–15 gains aftermarket intercooler; T4 BMW 320i 14–15 loses it.
T4 Ride Height Correction for the T3 Solstice. #34615suspension & brakessuspension & brakesT3 and T2 Pontiac Solstice GXP 07-09 minimum ride height set to 3 inches.
FP Correct Intake Valve Size on 1500cc Midget/Spitfire #34419wordingwordingFP and HP Sprite and Spitfire 1500 intake valve size corrected to 36.6 mm, removing prior decimal specifications.
FP ITC to FP? #34286cars addedremoved · cars addedHP Volkswagen Rabbit Cabriolet 1780 removed; Rabbit 1588 and 1715 reclassified with year and body-type clarifications.
T4 2002-2006 Mini Cooper S R53 Spec Line Request #34336weight -50 lbs
FP Request to Classify Sonic and Fiesta in HP #34264cars addedaddedFord Fiesta HP model years change to 11-19; Chevrolet Sonic FP model years change to 12-19.
STL Clarify STL table B - IT spec notes on Tires #34187wordingwordingSTL ITA and ITS RX7, and ITS/ITA/ITB/ITC 1985+ models clarified to require tires per 9.1.4.2.
T4 Mustang OEM Grill Request #33333aeroadded · aeroT2 and T3 Mustang 11-14 may remove upper grille fog lights, replace with mesh or screen.
T4 Mazda OEM LSD was letter 32655 typo #33666wording
FP Review Limited Prep Port Matching Rules #33600wordingwordingEP, FP, HP port matching limited to 1 inch depth from mating surface.
STL Spec MX5 in STL #33473cars addedaddedSpec MX5 in STL allows ACT clutch 0000-02-5004-G6, wheels 17x8, Toyo RR and RA1 235-40-17 tyres, or alternatives on 17x7 per rules.
T4 Allowable Springs and Sway Bars for 06-11 Civic si Spec Line #33294suspension & brakes
T4 Touring (T2-T5) Category #33617cars addedaddedT5 touring class added; T2-T5 cars may race one class up; T5 maximum tyre width 225 with minimum aspect ratio 45.
T4 ENO 9.1.9.2.D.1.e.1.a. #33651wordingwordingT2-T5 Touring front and rear suspension maximum negative camber clarified to 3.5 degrees.
2:05.474Danny Steyn · fastest of 24 · top 5 within 2.3s-1.729s (-1.36%)
2:07.832Danny Steyn · fastest of 22 · top 5 within 1.9s+0.559s (+0.44%)
131.7Trever Degioanni-3.2 mph (-2.3%)
2:02.162Kurt Rezzetano · fastest of 13 · top 5 within 2.3s-0.776s (-0.63%)
2:04.578Gregory Eaton · fastest of 11 · top 5 within 2.9s+0.678s (+0.55%)
150.9James Jost-3.0 mph (-2.0%)
-3.254squal -3.312s
97.5%qual 97.4%
2:09.577John Heinricy · fastest of 18 · top 5 within 0.7s-1.680s (-1.28%)
2:25.443John Heinricy · fastest of 18 · top 5 within 2.5s+14.484s (+11.06%)
127.4Nick Leverone-1.5 mph (-1.2%)
+17.611squal +4.103s
113.8%qual 103.3%
2:06.217Eric Prill · fastest of 18 · top 5 within 1.5s-1.219s (-0.96%)
2:17.641Mason Workman · fastest of 15 · top 5 within 3.2s+9.565s (+7.47%)
132.5Cliff Ira+1.2 mph (+0.9%)
+9.809squal +0.743s
107.7%qual 100.6%
68 rule changes (STL: 5, AS: 9, T4: 29, FP: 25)10 weight · 9 engine · 8 cars added · 8 tyres & wheels · 6 suspension & brakes · 4 induction · 2 aero · 1 removed · 13 wording · 7 other · AS adds Hoosier W2 wet tyre option alongside R7, R6, WET/H20. · AS Dodge Challenger 08-20 gains two transmission ratio options: 2.97–0.50 or 2.26–0.63. · Volkswagen New Beetle 2.5L 5-cyl DOHC classified in EP at 2400–2520 lbs with fuel injection. · EP Mazda RX-7 12A/13B and 13B now permit 2 bbl fuel injected throttle body with 42mm chokes on dual-y manifold. · EP VW Corrado 92-95 stroke corrected to 90.3 mm and displacement to 2792 cc. · AS Cadillac CTS-V 6.0L V8 Restricted Prep removes 295 tire size 50 lb penalty. · EP Subaru BRZ title updated to include model years 13–20; Toyota 86/Scion FR-S title likewise updated to 13–20. · FP Lotus Super Seven 91.7 ci minimum weight increases 50 lbs, to 1580. · EP Mazda MX-5 Global Cup 16-22 minimum weight set to 2400 lbs; sequential gearbox allowed with 150 lbs penalty. · BMW 128i (08-13) classified in EP at 2700 lbs minimum with 2996 cc engine, stock throttle body, 11.0:1 compression and 0.400" valve lift limits. · EP, FP, HP open cars now allow carbon fiber hardtops if they retain OEM exterior profiles. · Mazda Protégé ES 99-00 classified FP, 2150–2258 lbs, 1839 cc DOHC, fuel injection, 11.0:1 compression, 0.450" valve lift. · T2-T4 Touring cars with alternative springs now permitted to use performance top hats with spherical bearings on shocks and struts. · EP Mazda RX-8 13B carburetor option replaced with fuel-injected throttle body or stock fuel injection. · EP, FP, HP Production clarify idle control valve options: stock original allowed, removable with blocked ports, or mechanical replaced with electronic stock type. · FP BMW 325e/es displacement corrected to 2693 cc. · T2-T4 touring cars model year 2018+ may use aftermarket ECU with 75 lb weight penalty via spec line adjustment. · EP BMW Z3 2.5L intake restrictor reduced from 59mm to 58mm flat plate. · Ford Mustang 94-98 weight reduced to 2550/2614/2678 lbs; 99-03 3.8L classified EP at 2700/2768/2835 lbs. · EP, FP, HP Improved Touring cars may use any DOT-approved tyre as defined by 9.3.45. · FP VW Golf III/Jetta III 93-98 intake valve shrinks to 39.5 mm (1.56 in), exhaust to 32.9 mm (1.30 in). · STU single throttle body weight reduction removed; minimum weights revised down to 2990 lbs at 3000cc from 3300 lbs. · STL and STU Improved Touring vehicles must now conform to section 9.1.4 Tires & Wheels. · T2-T4 grill opening removal for cooling permitted without 16 square inch limit; mesh shape must match factory. · EP, FP, HP: stock/original idle control devices permitted unmodified or completely removed with openings blocked. · SMG Long Tube Headers: Borla PN 17237 discontinued, approved alternatives American Racing MT3-05134300LSNC or Kooks PN 11312000. · AS Mercury Capri 79-86 removed as separate spec line, merged into Ford Mustang 79-93 spec line. · AS Spec Mustang SMG Restricted Prep removes 3.73 gear ratio and 355/300 brake disc sizes. · AS Camaro, Firebird, Mustang full prep engines: alternate GM and Ford Performance cylinder heads permitted regionally with Allstar restrictor ALL26180. · EP Porsche 968 intake valve size changes to 39.0 mm, 1.54 mm seat width. · EP, FP, HP front-wheel-drive cars may alter body and subframes to install alternate axle shaft, matching RWD freedom. · EP BMW Z3 2.5L adds alternate throttle body option with Turner adapter and permits head casting 1738400. · FP Honda Civic Del Sol VTEC compression ratio limited to 11.0:1, valve lift to .425", removes dry sump and internal engine prep allowances. · FP Honda Prelude 84-87 and Mazda GLC/323 86-88 valve lift measurement method clarified, Level 1 parts list removed. · STL/STU intake manifold and cylinder head porting clarified as free; intake and exhaust porting wording removed. · STL Mazda Renesis flat plate restrictor increases from 55mm to 60mm. · STL 79-85 RX7 12A allows emissions removal and jet correction on stock Nikki carb. · T2, T3, T4 clarify grill opening removal limited to 16 square inches for radiator cooling; mesh shape must be retained. · T2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted. · T2, T3, T4: clarified that 'permitted' or 'allowed' parts in spec lines are alternatives to category rule allowances, not replacements. · EP Porsche 944S2 89-91 requires 56mm flat plate intake restrictor; compression ratio 12.0:1 max, valve lift 0.500" max, dry sump allowed. · Toyota Corolla GTS RWD (84-87) and FX16 FWD (87-88) added to HP; old Corolla (84-87) removed. · T4 adds 2014 VW Jetta 1.8T TSI to Spec Lines. · AS Chevrolet/Pontiac Camaro & Firebird 93-02 gains BMR AA004 or UMI 2310 adjustable front upper control arms. · AS Pontiac GTO 04-06 Restricted Prep minimum weight rises: LS1 to 3300 lbs, LS2 to 3350 lbs on 295 tires. · Toyota MR-2 1.6L 85-89 HP track width corrected to 15×47 / 15×47 inches; stock track baseline now 103% plus 2.5 inches.showhide
AS Request to add Hoosier W2 #33031tyres & wheelsadded · tyres & wheelsAS adds Hoosier W2 wet tyre option alongside R7, R6, WET/H20.
AS correction of Dodge Challenger specification line #33151cars addedaddedAS Dodge Challenger 08-20 gains two transmission ratio options: 2.97–0.50 or 2.26–0.63.
FP Request to classify VW New Beetle 2.5L in EP #32725cars addedaddedVolkswagen New Beetle 2.5L 5-cyl DOHC classified in EP at 2400–2520 lbs with fuel injection.
FP Request Rotary Injection on Dual Y manifold #32775inductionadded · inductionEP Mazda RX-7 12A/13B and 13B now permit 2 bbl fuel injected throttle body with 42mm chokes on dual-y manifold.
FP Request for Corrado Stroke & Displacement Correction #32985wordingwordingEP VW Corrado 92-95 stroke corrected to 90.3 mm and displacement to 2792 cc.
FP Subaru BRZ Model Years #32500wordingwordingEP Subaru BRZ title updated to include model years 13–20; Toyota 86/Scion FR-S title likewise updated to 13–20.
T4 Request Wider Wheels for Hyundai Tiburon #32536tyres & wheels
FP Weight Adjustment of Lotus 7 #32213weight +50 lbsslower · weightFP Lotus Super Seven 91.7 ci minimum weight increases 50 lbs, to 1580.
FP EP MX-5 Global Cup Car #32218weightweightEP Mazda MX-5 Global Cup 16-22 minimum weight set to 2400 lbs; sequential gearbox allowed with 150 lbs penalty.
FP Please Class BMW 128i in EP #32370cars addedaddedBMW 128i (08-13) classified in EP at 2700 lbs minimum with 2996 cc engine, stock throttle body, 11.0:1 compression and 0.400" valve lift limits.
FP Inconsistency in Body Work Descriptions #32396aeroadded · aeroEP, FP, HP open cars now allow carbon fiber hardtops if they retain OEM exterior profiles.
FP Request to classify the 1999-2000 Mazda Protege in FP #32398cars addedaddedMazda Protégé ES 99-00 classified FP, 2150–2258 lbs, 1839 cc DOHC, fuel injection, 11.0:1 compression, 0.450" valve lift.
T4 Request to Add Spec Line for 2004-2009 Mazda3 i 2.0 #32395weight
T4 Request Alternate Front & Rear Strut/Shock Top Hats #32452suspension & brakesadded · suspension & brakesT2-T4 Touring cars with alternative springs now permitted to use performance top hats with spherical bearings on shocks and struts.
FP Mazda RX8 with 13b Rotary #32170engineengineEP Mazda RX-8 13B carburetor option replaced with fuel-injected throttle body or stock fuel injection.
FP Request Idle control valve clarification #32178wordingwordingEP, FP, HP Production clarify idle control valve options: stock original allowed, removable with blocked ports, or mechanical replaced with electronic stock type.
FP Correct FP BMW 325e/es Displacement #32394wordingunclearFP BMW 325e/es displacement corrected to 2693 cc.
T4 Request to Allow the Use of Aftermarket ECU's in Touring #31067engineadded · engineT2-T4 touring cars model year 2018+ may use aftermarket ECU with 75 lb weight penalty via spec line adjustment.
T4 Request JWT BSR Kit for 02-06 Nissan Sentra SE-R/Spec V #31685other
T4 Please Confirm Touring 4 (98-00) BMW 323 is E46 generation #31972other
T4 RX-8 Spring Part Numbers (E&O) #32151suspension & brakes
FP EP Adjustments #31858inductionslower · inductionEP BMW Z3 2.5L intake restrictor reduced from 59mm to 58mm flat plate.
FP 1999 3.8L Ford Mustang to EP? #31635weightfaster · weightFord Mustang 94-98 weight reduced to 2550/2614/2678 lbs; 99-03 3.8L classified EP at 2700/2768/2835 lbs.
FP Improved Touring Tires #32064tyres & wheelsadded · tyres & wheelsEP, FP, HP Improved Touring cars may use any DOT-approved tyre as defined by 9.3.45.
FP VW Golf Jetta 2.0L intake and exhaust size correction. #32173engineslower · engineFP VW Golf III/Jetta III 93-98 intake valve shrinks to 39.5 mm (1.56 in), exhaust to 32.9 mm (1.30 in).
STL Single TB Weight Modifiers #31449weightfaster · weightSTU single throttle body weight reduction removed; minimum weights revised down to 2990 lbs at 3000cc from 3300 lbs.
STL Improved Touring Tires #32063tyres & wheelstyres & wheelsSTL and STU Improved Touring vehicles must now conform to section 9.1.4 Tires & Wheels.
T4 Reply to letter #31486/29879 T2-T4 Grill openings #31935aerofaster · aeroT2-T4 grill opening removal for cooling permitted without 16 square inch limit; mesh shape must match factory.
FP Throttle Body and Idle Air #31800wordingwordingEP, FP, HP: stock/original idle control devices permitted unmodified or completely removed with openings blocked.
T4 Request Allowances for 2005 - 2010 Mustang #31624wording
AS Proposed Revisions to SCCA GCR 2021 Appendix M, Part 3 #30295wordingwordingSMG Long Tube Headers: Borla PN 17237 discontinued, approved alternatives American Racing MT3-05134300LSNC or Kooks PN 11312000.
AS specification line consolidation and correction #31846cars addedremoved · cars addedAS Mercury Capri 79-86 removed as separate spec line, merged into Ford Mustang 79-93 spec line.
AS correction of SMG specification line #31847wordingremovedAS Spec Mustang SMG Restricted Prep removes 3.73 gear ratio and 355/300 brake disc sizes.
AS Alternate cylinder heads for full prep engine builds - Evaluation #31851engineadded · engineAS Camaro, Firebird, Mustang full prep engines: alternate GM and Ford Performance cylinder heads permitted regionally with Allstar restrictor ALL26180.
FP Porsche 968 Engine Questions #31478engineengineEP Porsche 968 intake valve size changes to 39.0 mm, 1.54 mm seat width.
FP PCS E. 2. n. 4. Add Axle Shaft to Allow FWD the Same Freedom #31592otheraddedEP, FP, HP front-wheel-drive cars may alter body and subframes to install alternate axle shaft, matching RWD freedom.
FP BMW Z3 2.5L Spec Line #31724engineadded · engineEP BMW Z3 2.5L adds alternate throttle body option with Turner adapter and permits head casting 1738400.
FP FP Del Sol VTEC #31859engineslower · engineFP Honda Civic Del Sol VTEC compression ratio limited to 11.0:1, valve lift to .425", removes dry sump and internal engine prep allowances.
FP Standardize Level 2 Classifications in FP #31868wordingwordingFP Honda Prelude 84-87 and Mazda GLC/323 86-88 valve lift measurement method clarified, Level 1 parts list removed.
STL Throttling Device Clarification #31323wordingwordingSTL/STU intake manifold and cylinder head porting clarified as free; intake and exhaust porting wording removed.
STL Mazda Renesis Restriction #31467enginefaster · engineSTL Mazda Renesis flat plate restrictor increases from 55mm to 60mm.
STL Clarification of 79-85 RX7 Spec line #31621wordingwordingSTL 79-85 RX7 12A allows emissions removal and jet correction on stock Nikki carb.
T4 Reply to letter 29879 T2-T4 Grill Openings #31486wordingwordingT2, T3, T4 clarify grill opening removal limited to 16 square inches for radiator cooling; mesh shape must be retained.
T4 Please Adjust 98-00 BMW 323 Min Weight to Reflect Current Class #31595weight -200 lbs
T4 Consolidate 12-13 and 14-15 Honda Civic Si spec lines for T4 #31596removed
T4 Request to clarify radiator hoses #31682otheraddedT2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted.
T4 Clarify Permitted/Allowed #31743wordingwordingT2, T3, T4: clarified that 'permitted' or 'allowed' parts in spec lines are alternatives to category rule allowances, not replacements.
FP Classing Clarification for 1986 Toyota Corolla FX16 #31527cars addedaddedToyota Corolla GTS RWD (84-87) and FX16 FWD (87-88) added to HP; old Corolla (84-87) removed.
T4 Adjust Honda FWD in T4 to encourage more Drivetrain Diversity #31472tyres & wheels
T4 Touring 4 BOP adjustments for 2022 #31482weight -175 lbs
T4 Request to Classify 2014 VW Jetta 1.8t TSI #30436cars addedaddedT4 adds 2014 VW Jetta 1.8T TSI to Spec Lines.
AS Request for adjustable Front Upper Control Arms on 4th Gen F-Body #30457otheraddedAS Chevrolet/Pontiac Camaro & Firebird 93-02 gains BMR AA004 or UMI 2310 adjustable front upper control arms.
AS Request Pontiac GTO tire size change #30881weightslower · weightAS Pontiac GTO 04-06 Restricted Prep minimum weight rises: LS1 to 3300 lbs, LS2 to 3350 lbs on 295 tires.
FP E&O; MR2 Track #31120suspension & brakessuspension & brakesToyota MR-2 1.6L 85-89 HP track width corrected to 15×47 / 15×47 inches; stock track baseline now 103% plus 2.5 inches.
1:51.665Danny Steyn · fastest of 42 · top 5 within 1.7s-0.982s (-0.87%)
2:02.711Joe Moser · fastest of 37 · top 5 within 3.2s+10.122s (+8.99%)
131.8Max Gee
1:50.427Drew Cattell · fastest of 31 · top 5 within 1.9s+5.207s (+4.95%)
1:50.606Gregory Eaton · fastest of 28 · top 5 within 1.7s-0.901s (-0.81%)
153.8James Jost
-12.105squal -1.238s
90.1%qual 98.9%
1:54.397Stephen Blethen · fastest of 47 · top 5 within 0.9s-2.169s (-1.86%)
1:55.929John Heinricy · fastest of 46 · top 5 within 1.0s-0.994s (-0.85%)
127.3Alexander Schefer
-6.782squal +2.732s
94.5%qual 102.4%
1:51.082Craig Chima · fastest of 39 · top 5 within 1.2s-1.009s (-0.90%)
1:59.933Cliff Ira · fastest of 33 · top 5 within 5.4s+6.926s (+6.13%)
131.8Cliff Ira
-2.778squal -0.583s
97.7%qual 99.5%
70 rule changes (STL: 15, AS: 14, T4: 20, FP: 21)20 cars added · 15 weight · 6 engine · 4 induction · 3 tyres & wheels · 2 aero · 2 suspension & brakes · 11 wording · 7 other · STL Mazda Spec MX-5 removes redundant specification line referencing 2014 regulations. · EP Honda S2000 now allows F22c engine in 1997cc and 2157cc displacements with revised weight brackets and specifications. · EP Nissan 240-SX S13/S14 weight drops to 2400 lbs base, 2460 turbo, 2520 supercharged; comp ratio raised to 12.0:1, valve lift to 0.500 inch. · EP Lotus/Caterham 7 America fuel injection permitted; IT preparation engine limitation removed. · Plymouth Arrow 76–80 classified in HP Prep at 1800–1890 lbs with 1598 cc iron-block OHV four-cylinder. · BMW 318i/is E30 (84-85) reclassified from FP to HP at 2200–2310 lbs, SOHC 1797cc, fuel injection, 11.0:1 compression, .425" valve lift limit. · FP Fiat X1/9 1300 loses 50 lbs to 1665; X1/9 Bertone loses 50 lbs to 1765. · Daimler SP 250 classified in EP with 2165 lbs minimum weight, 2548 cc eight-cylinder OHV engine, SU or Stromberg carburetors. · AS Cadillac CTS-V 6.0L LS6 removes 295-tire 50 lb penalty. · AS consolidates seven SN95 Mustang '94-'04 spec lines into three unified lines by model year and engine. · AS Camaro/Firebird LT1 and LS1 transmission changed to TUET1 6362; Mustang GT 4.6L/5spd to TUKT16901, loses 300 lbs. · AS Camaro & Firebird and Mustang GT gear ratio specifications restored with alternate sets permitted. · AS Camaro, Firebird, Mustang, and Capri all gain 50 lbs minimum weight across seven model year variants. · Porsche 924 Level 1 Prep moved from EP to FP classification. · EP, FP, HP clarify percentage weight penalties sum before applying to base weight, round to nearest pound. · STL Volkswagen 2.0L TFSI 1984 cc engine permitted without turbocharger, meeting all other STL specs. · T3 Honda Civic Type-R 2020+ allowed brake rotor #45251-TGH-A01 with 25 lb penalty. · 84-87 Mazda 626 reclassified from FP to HP with 2300–2415 lb weight, 1998cc SOHC engine, two 32mm carburetors. · FP Fiat X1/9 and Bertone 1300 brake rotors now 257 x 12 mm, 10.1 inch diameter, 0.407 inch thickness. · STL Pontiac Solstice/Saturn Sky allowed 4 inch ride height. · STL Mazda B5 DOHC added to class; must meet all STL regulations. · STL Honda B16A (JDM) restrictor reduced from 54mm to 53mm. · Mazda 3 S 04-08 classified in EP at 2350 lbs minimum, 2.26L DOHC four-cylinder, fuel injected with 55mm throttle body, comp ratio 12.0:1 max, valve lift 0.500" max. · FP Volkswagen Golf and Jetta III and IV intake valves increase to 40.0 mm, exhaust to 33.0 mm. · ST oil coolers and filters now explicitly listed as addable or substitutable parts in vents and breathers section. · T2-T4 clutch discs and pressure plates must be at least 95% of factory OEM weight, bolted to unmodified stock flywheel. · AS Mustang 4.6L 5spd gains cold air intake freedom; 5.0L 6spd now requires 56mm flat plate restrictor. · AS CTS-V 5.7L LS6 and 6.0L LS2 may use Driveshaft Shop P/N GMCTSV2-C carbon fiber driveshaft. · AS Chevrolet Camaro SS V8 6.2L Restricted Prep model years extended from 10–13 to 10–15. · STL GM Ecotec LNF now permits any Ecotec engine family with 55mm flat plate restrictor. · ST 90-05 Mazda Miata allowed alternate front wheel hub Mazda Motorsports Development Part #0000-04-5HUB-S1. · ST cars may now relocate ABS actuation hardware and wiring anywhere in the engine compartment. · STL rear wing trailing edge may be mounted no further rearward than the center of the rearmost part approved bodywork. · STL alternate transmissions now allow OEM gear sets and input shaft modifications for fitment. · Toyota Supra 2020- added to T2 with 2998 cc engine, 3450 lbs minimum weight, 19×10 wheels, 295 tyres. · AS Ford Mustang GT 5.0L 15-17 Restricted added to Spec Line with 3600 lbs minimum weight, 55mm restrictor, 18×10 wheels, 295 tires. · AS underhood bracing on stock hoods, trunks, and rear decks may be modified or removed. · AS Cadillac CTS-V 04-07 with 295 tire drops to 3450 lbs; Camaro SS V8 10-13 and Challenger 08-20 specs removed. · AS Camaro & Firebird (93-02) and Mustang GT (05-14) specifications restored with weight minimums 3250–3500 and 3350–3600 lbs respectively. · EP Austin-Healey 3000 gains option to use TR-6 front calipers and discs as alternate. · FP Volkswagen Golf 1.8, Jetta, Rabbit and Scirocco gain 50 lb weight breaks, minimum weights to 1900–1733 lbs. · STL RWD strut-front cars lose 2.5% weight penalty, others lose 3% penalty for FWD parity. · STL Honda F20C drops 2% weight penalty, minimum weight reduced. · STL Honda B16/B17/B18C1 restrictor reduced to 53mm, B18C variants and Mazda MZR to 52mm. · T2 BMW M2 CS Cup 2020+ classified at 2979 cc, 3625 lbs, 295 tires, 10.5×18 wheels, 380/390 mm brakes. · T4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.55 final drive, plus 25 lb penalty. · T3 Scion FR-S/Toyota 86 and Subaru BRZ capped to 2021 model year; T4 models capped to 2021. · AS Dodge Challenger gains 6.1L and 6.4L V8 options; 5.7L weight rises to 3500 lbs on 295 tyres, 3600 on 315 tyres; compression to 10.9:1 max. · AS Camaro & Firebird (93-02) and Ford Mustang Coupe GT (05-14) spec lines consolidated; Camaro/Firebird now allows both LT1 and LS1 engines; Mustang now allows both 4.6L 3-valve and 5.0L 4-valve engines with restrictor. · FP Mk2 Golf and Jetta 1.8 lose 50 lbs to 1900; HP Jetta GLI engine code removed. · EP, FP, HP Level 1 and Level 2 induction systems: carburettor jets, needles, metering rods allowed; throttle body porting permitted; wording clarified. · EP Nissan Datsun SRL 311U Roadster minimum weight reduced 75 lbs to 1925. · EP Triumph TR8 78-81 minimum weight drops to 2500 lbs. · Honda Civic EX 96-00 classified FP2 at 1975 lbs, SOHC 1590cc, fuel injection, 56mm throttle body, comp ratio 12.0:1 max, valve lift 0.450" max. · FP adds FAJS to permitted Weber-type and auto-type carburetor substitutes in two sections. · ST aero devices and reference areas must include end plates, exclude fasteners under 1/2" protrusion. · T3 Alfa Romeo 4C Launch Edition variant now allowed.showhide
STL Request to clean up Spec MX-5 Redundancy #31069wordingwordingSTL Mazda Spec MX-5 removes redundant specification line referencing 2014 regulations.
FP Request to Allow F22c Engine for 2000-2003 Honda S2000 #30548cars addedaddedEP Honda S2000 now allows F22c engine in 1997cc and 2157cc displacements with revised weight brackets and specifications.
FP Request a review of the S14 240SX in EP. #30873weight -200 lbsfaster · weightEP Nissan 240-SX S13/S14 weight drops to 2400 lbs base, 2460 turbo, 2520 supercharged; comp ratio raised to 12.0:1, valve lift to 0.500 inch.
FP Lotus/Caterham 7 America Request #30392wordingwordingEP Lotus/Caterham 7 America fuel injection permitted; IT preparation engine limitation removed.
FP Request to classify ITC Plymouth Arrow #30588cars addedaddedPlymouth Arrow 76–80 classified in HP Prep at 1800–1890 lbs with 1598 cc iron-block OHV four-cylinder.
FP Reclassification of the 1984/85 BMW 318i from FP to HP #30661cars addedaddedBMW 318i/is E30 (84-85) reclassified from FP to HP at 2200–2310 lbs, SOHC 1797cc, fuel injection, 11.0:1 compression, .425" valve lift limit.
FP Fiat x1/9 Competition Adjustments #30711weight -50 lbsfaster · weightFP Fiat X1/9 1300 loses 50 lbs to 1665; X1/9 Bertone loses 50 lbs to 1765.
FP Reclassify Daimler SP 250 #30721cars addedaddedDaimler SP 250 classified in EP with 2165 lbs minimum weight, 2548 cc eight-cylinder OHV engine, SU or Stromberg carburetors.
T4 Wrong Part Number on 320i Spec Line #30645wording
AS Request CTS-V Spec Line Error Correction #30242weightfaster · weightAS Cadillac CTS-V 6.0L LS6 removes 295-tire 50 lb penalty.
AS Request to consolidate SN95 Mustang '94-'04 Mustang spec lines #30428wordingwordingAS consolidates seven SN95 Mustang '94-'04 spec lines into three unified lines by model year and engine.
AS American Sedan Transmission Rule Change Request #30595enginefaster · engineAS Camaro/Firebird LT1 and LS1 transmission changed to TUET1 6362; Mustang GT 4.6L/5spd to TUKT16901, loses 300 lbs.
AS Correction to specifications inadvertently deleted #30691wordingwordingAS Camaro & Firebird and Mustang GT gear ratio specifications restored with alternate sets permitted.
AS weight adjustments #30700weight +50 lbsslower · weightAS Camaro, Firebird, Mustang, and Capri all gain 50 lbs minimum weight across seven model year variants.
FP Move Porsche 924 in Level 1 Prep From EP to FP #30135cars addedaddedPorsche 924 Level 1 Prep moved from EP to FP classification.
FP Clarify Application of Percentage Based Weight Penalties #30669wordingwordingEP, FP, HP clarify percentage weight penalties sum before applying to base weight, round to nearest pound.
STL VW Engine Request #30625engineadded · engineSTL Volkswagen 2.0L TFSI 1984 cc engine permitted without turbocharger, meeting all other STL specs.
T4 Civic Type R Brake Rotors #29817weightslower · weightT3 Honda Civic Type-R 2020+ allowed brake rotor #45251-TGH-A01 with 25 lb penalty.
FP Change Classification of 84-87 Mazda 626 from FP to HP #30350cars addedadded84-87 Mazda 626 reclassified from FP to HP with 2300–2415 lb weight, 1998cc SOHC engine, two 32mm carburetors.
FP Fiat X1/9 brake rotors #30423otherotherFP Fiat X1/9 and Bertone 1300 brake rotors now 257 x 12 mm, 10.1 inch diameter, 0.407 inch thickness.
FP Please Classify Mazda3 in FP #30165cars addedaddedMazda 3 S 04-08 classified in EP at 2350 lbs minimum, 2.26L DOHC four-cylinder, fuel injected with 55mm throttle body, comp ratio 12.0:1 max, valve lift 0.500" max.
FP Golf MkIII Valve Size Request #30268enginefaster · engineFP Volkswagen Golf and Jetta III and IV intake valves increase to 40.0 mm, exhaust to 33.0 mm.
STL ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wordingwordingST oil coolers and filters now explicitly listed as addable or substitutable parts in vents and breathers section.
T4 Request consistency review in GCR #30263wordingwordingT2-T4 clutch discs and pressure plates must be at least 95% of factory OEM weight, bolted to unmodified stock flywheel.
AS AS Mustang LP 4.6 3V Classification Transmission Request #29886enginefaster · engineAS Mustang 4.6L 5spd gains cold air intake freedom; 5.0L 6spd now requires 56mm flat plate restrictor.
AS Request CF driveshaft on CTS-V for durability improvement #30117otheraddedAS CTS-V 5.7L LS6 and 6.0L LS2 may use Driveshaft Shop P/N GMCTSV2-C carbon fiber driveshaft.
AS Adjustment to model years of 5th generation RP Camaro #30348cars addedaddedAS Chevrolet Camaro SS V8 6.2L Restricted Prep model years extended from 10–13 to 10–15.
STL GM Ecotec engines in STL #30247engineadded · engineSTL GM Ecotec LNF now permits any Ecotec engine family with 55mm flat plate restrictor.
STL Super Touring Alternate Miata Hubs #30345cars addedaddedST 90-05 Mazda Miata allowed alternate front wheel hub Mazda Motorsports Development Part #0000-04-5HUB-S1.
STL Brake Component Relocation #29990suspension & brakessuspension & brakesST cars may now relocate ABS actuation hardware and wiring anywhere in the engine compartment.
STL Super Touring Wing Clarification #30111aeroaeroSTL rear wing trailing edge may be mounted no further rearward than the center of the rearmost part approved bodywork.
STL Transmission Options #30118otheraddedSTL alternate transmissions now allow OEM gear sets and input shaft modifications for fitment.
T4 2021 Toyota Supra #29567cars addedaddedToyota Supra 2020- added to T2 with 2998 cc engine, 3450 lbs minimum weight, 19×10 wheels, 295 tyres.
T4 Change part numbers on BRZ, FRS lines in T4 #30104wording
T4 T4 Mustang Axle Ratio and Wheels #30149tyres & wheels
AS Request for 2015 -2017 Ford Mustang Spec Line #29514cars addedaddedAS Ford Mustang GT 5.0L 15-17 Restricted added to Spec Line with 3600 lbs minimum weight, 55mm restrictor, 18×10 wheels, 295 tires.
AS Request Trunk lid / Rear Hatch clarification #29591wordingwordingAS underhood bracing on stock hoods, trunks, and rear decks may be modified or removed.
AS Common Weight for CTS-V Tire #29759weightfaster · weightAS Cadillac CTS-V 04-07 with 295 tire drops to 3450 lbs; Camaro SS V8 10-13 and Challenger 08-20 specs removed.
AS Correction to specifications inadvertently deleted #30041cars addedaddedAS Camaro & Firebird (93-02) and Mustang GT (05-14) specifications restored with weight minimums 3250–3500 and 3350–3600 lbs respectively.
FP Alternate Front Brake Rotors and Calipers for EP AH 3000 #29893otherotherEP Austin-Healey 3000 gains option to use TR-6 front calipers and discs as alternate.
FP Request VW weight break #29963weight -50 lbsfaster · weightFP Volkswagen Golf 1.8, Jetta, Rabbit and Scirocco gain 50 lb weight breaks, minimum weights to 1900–1733 lbs.
STL Request for FWD and RWD Parity #29728weightfaster · weightSTL RWD strut-front cars lose 2.5% weight penalty, others lose 3% penalty for FWD parity.
STL Request for FWD and RWD Parity #30023inductionslower · inductionSTL Honda B16/B17/B18C1 restrictor reduced to 53mm, B18C variants and Mazda MZR to 52mm.
T4 Request to Classify BMW M2 CS #29523cars addedaddedT2 BMW M2 CS Cup 2020+ classified at 2979 cc, 3625 lbs, 295 tires, 10.5×18 wheels, 380/390 mm brakes.
T4 Allow the SpecMX-5 Update Kit Into Touring 4 for the MX-5 #29681other
T4 Request Mustang 8.8†rear axle replacement #29860cars addedaddedT4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.55 final drive, plus 25 lb penalty.
T4 Cap year range on all 86s #29908wordingwordingT3 Scion FR-S/Toyota 86 and Subaru BRZ capped to 2021 model year; T4 models capped to 2021.
AS Request Additional Engine Options for Dodge Challenger Spec Line #29543cars addedaddedAS Dodge Challenger gains 6.1L and 6.4L V8 options; 5.7L weight rises to 3500 lbs on 295 tyres, 3600 on 315 tyres; compression to 10.9:1 max.
AS Rule simplification spec line communization #29824cars addedcars addedAS Camaro & Firebird (93-02) and Ford Mustang Coupe GT (05-14) spec lines consolidated; Camaro/Firebird now allows both LT1 and LS1 engines; Mustang now allows both 4.6L 3-valve and 5.0L 4-valve engines with restrictor.
FP Mk2 VW Consistency and Cleanup of FP and HP Spec Lines #29195weight -50 lbsfaster · weightFP Mk2 Golf and Jetta 1.8 lose 50 lbs to 1900; HP Jetta GLI engine code removed.
FP Correct Wording for Level 1 and Level 2 Induction Systems #29406inductionfaster · inductionEP, FP, HP Level 1 and Level 2 induction systems: carburettor jets, needles, metering rods allowed; throttle body porting permitted; wording clarified.
FP EP TR8 Adjustment #29512weight -100 lbsfaster · weightEP Triumph TR8 78-81 minimum weight drops to 2500 lbs.
FP Request to Classify 1996-2000 Honda Civic EX #29515cars addedaddedHonda Civic EX 96-00 classified FP2 at 1975 lbs, SOHC 1590cc, fuel injection, 56mm throttle body, comp ratio 12.0:1 max, valve lift 0.450" max.
FP FAJS Carburetor #29576cars addedaddedFP adds FAJS to permitted Weber-type and auto-type carburetor substitutes in two sections.
STL Request clarification on wing measurement #29640aeroaeroST aero devices and reference areas must include end plates, exclude fasteners under 1/2" protrusion.
2:31.420Danny Steyn · fastest of 33 · top 5 within 3.1s
2:32.115Joe Moser · fastest of 30 · top 5 within 1.5s
132.9Darin Treakle
2:27.045Gregory Eaton · fastest of 18 · top 5 within 0.6s
2:27.668Gregory Eaton · fastest of 15 · top 5 within 1.5s
149.2Gregory Eaton
-4.447squal -4.375s
97.1%qual 97.1%
2:37.403John Heinricy · fastest of 20 · top 5 within 2.5s
2:37.881Chi Ho · fastest of 19 · top 5 within 1.6s
130.2Chi Ho
+5.766squal +5.983s
103.8%qual 104.0%
2:31.414Ethan Shippert · fastest of 23 · top 5 within 2.2s
2:34.033Kevin Ruck · fastest of 21 · top 5 within 2.3s
133.2Sam Henry
+1.918squal -0.006s
101.3%qual 100.0%
71 rule changes (STL: 11, AS: 16, T4: 25, FP: 19)19 cars added · 10 engine · 6 weight · 5 suspension & brakes · 2 aero · 2 tyres & wheels · 1 induction · 20 wording · 6 other · HP 84-87 Toyota Corolla wheel diameter increases from 13 to 15 inches. · AS Dodge Challenger 5.7L V8 now requires iron block instead of aluminum, compression to 10.5:1 max, intake valve 12.7 mm, exhaust 12.3 mm, intake timing 188 degrees, exhaust timing 205 degrees. · AS Dodge Challenger 08-14 rear spoiler: 1GL20RXF replaced with 1GL20TZZAB; 82211606 still permitted. · EP BMW Z3 2.5L cylinder head casting 1738400 permitted with iron block castings 1748933 or 1738566. · STL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis percentage additions, subtractions, and fixed pounds. · STL STU rear wing Gurney flap terminology clarified from wicker to Gurney flap in mounting and chord rules. · AS class pursuing specified list of eligible tires; list details unclear from text provided. · AS class tire eligibility list under development; no specifications changed yet. · AS Coyote Mustang restrictor plate under review for 2021; no change effective yet. · AS Restricted Prep 4.6 3V now permits conversion to 2 valve configuration. · AS Ford Mustang Coupe GT 4.6L 3V Restricted Prep now permits Ford Performance camshaft kit P/N M-6550-3V. · 2010-2014 Camaro remains classified in AS; no specification changes. · AS class cylinder head supplier discontinuation; replacement option pending for 2021 season. · AS Mustang, Capri, Camaro, and Firebird maximum brake rotor diameter increased from 12.2 to 13.1 inches. · unclear · Porsche 911 S 67-68 classified in EP at 1800–1890 lbs, 1991cc opposed 6-cylinder SOHC with 36mm carburetors. · FP Mazda 626 84-87 carburetor spec clarified to two auto-type sidedraft 32mm choke or fuel injection. · GT3 and STU add Borg-Warner EFR6258 turbocharger to approved turbo lists. · Request to add vehicle to T2, T3, T4 roster; refer to letter #27663 in June 2020 Fastrack for decision. · EP BMW 2.8L, 328i E36/E46, and 325i E36 now require iron blocks only; 325i E46 aluminum block removed. · FP Volkswagen Scirocco E&O adds four engine variants with weights 1520–1853 lbs and displacements 1471–1780 cc. · STL adds Mazda MX-5 Global Cup 16-18 at 2450 lbs minimum and 2019 at 2550 lbs minimum. · STL Mazda MX-5 Club 06-15 allowed header part number 0000-06-5407-NC. · STL Acura/Honda B18 and B18C engines: restrictor sizes swapped, B18C1 removed from allowed variants. · 2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine, 17-inch wheels, 245 tyres, EIBACH PN# 2563.140 springs allowed. · FP Pre: 1990–1994 Mazda Protégé classified at 2150–2258 lbs, 1839cc DOHC, fuel injection, 11.0:1 compression, .450" valve lift limit. · HP Mini Cooper 02-06 and 07-13 convertible model years corrected to 05-08 and 09-15 respectively. · STL Honda B18 loses 53mm restrictor requirement; B18C1 added with 54mm restrictor, B18C1 removed from other variants. · T3 BMW Z3 M & Coupe 98-99 minimum weight reduced to 3150 lbs. · EP Caterham 7 America engine limited to IT prep with specific sections, comp ratio 10.0:1, valve lift .380 inch. · 1989-90 Nissan 240-SX SOHC added to FP Pre L2 at 2400–2520 lbs, 2389 cc, fuel injection, 11.0:1 compression, .450" valve lift limit. · STU GM Ecotech LNF now permitted without turbo, with LE5 head and intake manifold, meeting STL specs. · STL Mazda MZR restrictor reduced from 54 mm to 53 mm. · STL Mazda MZR restrictor reduces from 55 mm to 53 mm. · FP Volkswagen Jetta, Rabbit, Scirocco reclassified with weights 1520–1853 lbs, intake valves 40.0 mm, exhaust 33.0 mm, throttle 35/52 mm. · HP Datsun 510 allows 40 DCOE carburetor option alongside existing 40 DCNF and 36mm DCNVH; auto side drafts moved to penalty structure. · Porsche 914-4 2.0L classified in FP Prep 2 at 2030–2132 lbs with 1968cc OHV engine, Solex/Weber/Dellorto carbs or fuel injection, 11.0:1 compression limit, .450" valve lift limit. · FP Ford Fiesta 78-80 minimum weight reduced 130 lbs, to 1660. · STL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL to notes. · AS rear trailing arms may be replaced with tubular arms maintaining stock length and axle location purpose only. · AS Ford and GM full prep cars get increased weight reduction from 150 to 200 lbs. · 05-10 Ford Mustang Coupe GT 4.6L OHC classified AS with 3200 lbs minimum weight, HR cam permitted. · 10-15 Camaro Full Prep classified AS with 3400 lbs base weight, 3700 lbs over 313 CID, specific head castings and Edelbrock heads permitted. · HP Datsun 1200 carburetor option changes from 26mm to 30mm choke(s) in 40 DCN, DCNF, IDF. · Pontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18x9.5, Sky weight drops to 3200 lbs. · Mazda RX-8 Base/R3/Sport/GT (04-12) classified in T3 effective 2020-02-01. · Mazda Miata models EP and FP throttle body specified 55mm, brake rotor thickness figures removed. · FP Mazda Protégé ES 2001–2003 newly classified at 2350–2468 lbs with 1991 cc DOHC four-cylinder, fuel injection, 11.0:1 compression, .450 in. valve lift limit. · T2 must have fire system installed; T3 and T4 may have one per GCR 9.3. · T3 Ford Mustang EcoBoost gains three transmission gear ratio options. · T3 and T4 Mazda RX-8 Base/R3 (04-12) reclassified to include Sport and GT variants. · Toyota 86 GT variant (2017–) added to T3 and T4 spec lines. · FP and HP: 1988–91 Honda Civic and CRX track widths corrected to 61.3 / 61.7 inches across multiple levels. · EP, FP, HP cylinder head rules reorganized for clarity; no performance change.showhide
FP 84-87 Toyota Corolla HP Wheel Diameter Allowance Proposal E&O #29458otherfasterHP 84-87 Toyota Corolla wheel diameter increases from 13 to 15 inches.
AS Dodge Challenger AS Spec Line Clarification #28698engineslower · engineAS Dodge Challenger 5.7L V8 now requires iron block instead of aluminum, compression to 10.5:1 max, intake valve 12.7 mm, exhaust 12.3 mm, intake timing 188 degrees, exhaust timing 205 degrees.
AS Dodge Challenger AS Spec Line Clarification #2 #28699aeroaeroAS Dodge Challenger 08-14 rear spoiler: 1GL20RXF replaced with 1GL20TZZAB; 82211606 still permitted.
FP EP BMW Z3 Rule Clarification #28998wordingwordingEP BMW Z3 2.5L cylinder head casting 1738400 permitted with iron block castings 1748933 or 1738566.
STL Minimum Weight Determination #27695wordingwordingSTL and STU clarify weight adjustment calculation order: engine adjustments first, then chassis percentage additions, subtractions, and fixed pounds.
STL ST Gurney flap Wicker clarification #29012wordingwordingSTL STU rear wing Gurney flap terminology clarified from wicker to Gurney flap in mounting and chord rules.
T4 Scion FRS Solo Spec Coupe Gear Ratio #29021other
AS Support for R-Type Specification Tires #27450wordingunclearAS class pursuing specified list of eligible tires; list details unclear from text provided.
AS Spec Tire Request #27519wordingunclearAS class tire eligibility list under development; no specifications changed yet.
AS Restrictor Plate Change for RP 2011+ Mustang with Coyote Engine #27675wordingunclearAS Coyote Mustang restrictor plate under review for 2021; no change effective yet.
AS 2005-2009 Restricted Prep 4.6 3V #27908engineadded · engineAS Restricted Prep 4.6 3V now permits conversion to 2 valve configuration.
AS Request for 2005-2009 Restricted Prep 4.6 3V Parts #27909engineadded · engineAS Ford Mustang Coupe GT 4.6L 3V Restricted Prep now permits Ford Performance camshaft kit P/N M-6550-3V.
AS Request for Full Preparation Classification for 2010-2014 Camaro #28030wordingunclear2010-2014 Camaro remains classified in AS; no specification changes.
AS Cylinder Heads #28696wordingunclearAS class cylinder head supplier discontinuation; replacement option pending for 2021 season.
AS Request for Max Rotor Diameter Change #28748otherfasterAS Mustang, Capri, Camaro, and Firebird maximum brake rotor diameter increased from 12.2 to 13.1 inches.
AS Request increase rotor diameter #28797wordingunclearunclear
FP Request to Classify Porsche 911 2.0L #28456cars addedaddedPorsche 911 S 67-68 classified in EP at 1800–1890 lbs, 1991cc opposed 6-cylinder SOHC with 36mm carburetors.
FP Request to change to Carburetor Spec Line 84-87 Mazda 626 #28926wordingwordingFP Mazda 626 84-87 carburetor spec clarified to two auto-type sidedraft 32mm choke or fuel injection.
STL Request for Addition to GT3 Approved Turbo List #27576cars addedaddedGT3 and STU add Borg-Warner EFR6258 turbocharger to approved turbo lists.
T4 Request to Add a Vehicle to the Roster (contd.) #27698wordingunclearRequest to add vehicle to T2, T3, T4 roster; refer to letter #27663 in June 2020 Fastrack for decision.
FP BMW Cylinder Head Casting and Part Numbers #28708engineslower · engineEP BMW 2.8L, 328i E36/E46, and 325i E36 now require iron blocks only; 325i E46 aluminum block removed.
FP Correct Scirocco Spec line E&O #28892cars addedaddedFP Volkswagen Scirocco E&O adds four engine variants with weights 1520–1853 lbs and displacements 1471–1780 cc.
STL Request to add 2016-2019 GMX-5 Spec line #28604cars addedaddedSTL adds Mazda MX-5 Global Cup 16-18 at 2450 lbs minimum and 2019 at 2550 lbs minimum.
STL Request to update PN for MX-5 #28622cars addedaddedSTL Mazda MX-5 Club 06-15 allowed header part number 0000-06-5407-NC.
STL Correction - Clarification Honda/Acura B18B engine Letter # 26209 #28873wordingwordingSTL Acura/Honda B18 and B18C engines: restrictor sizes swapped, B18C1 removed from allowed variants.
T4 Request to Classify 2004 Mercedes Benz 320 CLK #27663cars addedadded2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine, 17-inch wheels, 245 tyres, EIBACH PN# 2563.140 springs allowed.
AS weight adjustments for 2020 season #28785weight -50 lbs
FP Error in Mini Cooper Spec Line #28713wordingwordingHP Mini Cooper 02-06 and 07-13 convertible model years corrected to 05-08 and 09-15 respectively.
STL STL Honda B18 restrictor changes #28794enginefaster · engineSTL Honda B18 loses 53mm restrictor requirement; B18C1 added with 54mm restrictor, B18C1 removed from other variants.
T4 Request to change allowed header part # for T4 06-15 Miata #28223wording
T4 Z3M Roadster Weight #28437weightfaster · weightT3 BMW Z3 M & Coupe 98-99 minimum weight reduced to 3150 lbs.
FP Caterham 7 Spec Line #28498wordingwordingEP Caterham 7 America engine limited to IT prep with specific sections, comp ratio 10.0:1, valve lift .380 inch.
FP Request to classify SOHC 1989-90 240SX in F prod L2 #28553cars addedadded1989-90 Nissan 240-SX SOHC added to FP Pre L2 at 2400–2520 lbs, 2389 cc, fuel injection, 11.0:1 compression, .450" valve lift limit.
STL Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0 #27884engineadded · engineSTU GM Ecotech LNF now permitted without turbo, with LE5 head and intake manifold, meeting STL specs.
STL Acura/Honda B18C engine chart. Reduce the current 54 mm flat plat #28663engineslower · engineSTL Mazda MZR restrictor reduced from 54 mm to 53 mm.
STL Mazda MZR engine chart. Reduce the current 55 mm flat plate to 53 #28664engineslower · engineSTL Mazda MZR restrictor reduces from 55 mm to 53 mm.
FP VW Weight and Valve Size Request #27886wordingwordingFP Volkswagen Jetta, Rabbit, Scirocco reclassified with weights 1520–1853 lbs, intake valves 40.0 mm, exhaust 33.0 mm, throttle 35/52 mm.
FP Request to allow 40 DCOE carb for the Datsun 510 #28195engineadded · engineHP Datsun 510 allows 40 DCOE carburetor option alongside existing 40 DCNF and 36mm DCNVH; auto side drafts moved to penalty structure.
FP Request to classify Porsche 914 2L in LPrep FProd #28231cars addedaddedPorsche 914-4 2.0L classified in FP Prep 2 at 2030–2132 lbs with 1968cc OHV engine, Solex/Weber/Dellorto carbs or fuel injection, 11.0:1 compression limit, .450" valve lift limit.
FP Request Ford Fiesta Weight Adjustment #28336weightfaster · weightFP Ford Fiesta 78-80 minimum weight reduced 130 lbs, to 1660.
STL Request to add wheel part numbers #28342cars addedaddedSTL Mazda Spec MX5 Challenge adds approved wheel part numbers 0000-04-5706-GM, 0000-04-5706-SL to notes.
T4 Request for 12-13 and 14-15 Honda Civic Springs #27848suspension & brakes
T4 Request to Clarify T4 05-10 Mustang Spring Allowance #27899suspension & brakes
AS Rear Trailing Arms #28007suspension & brakesadded · suspension & brakesAS rear trailing arms may be replaced with tubular arms maintaining stock length and axle location purpose only.
AS Weight reduction for cars running iron heads #28010weightfaster · weightAS Ford and GM full prep cars get increased weight reduction from 150 to 200 lbs.
AS 05-10 Mustang with HR cam classification #28226cars addedadded05-10 Ford Mustang Coupe GT 4.6L OHC classified AS with 3200 lbs minimum weight, HR cam permitted.
AS 10-15 Camaro Full Prep classification #28227cars addedadded10-15 Camaro Full Prep classified AS with 3400 lbs base weight, 3700 lbs over 313 CID, specific head castings and Edelbrock heads permitted.
FP Request for Help for Datsun 1200 #27934inductionfaster · inductionHP Datsun 1200 carburetor option changes from 26mm to 30mm choke(s) in 40 DCN, DCNF, IDF.
T4 Request to Allow Brake Upgrade on T4 Mustang #27329suspension & brakes
T4 Please Switch the Solstice GXP as Specified in T2, to T3 #27413cars added -50 lbsfaster · cars addedPontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18x9.5, Sky weight drops to 3200 lbs.
T4 Request to Classify all Mazda RX8 Models in T3/T4 #27606cars addedaddedMazda RX-8 Base/R3/Sport/GT (04-12) classified in T3 effective 2020-02-01.
FP Request to List Mazda Miata Throttle Body Size #27907wordingwordingMazda Miata models EP and FP throttle body specified 55mm, brake rotor thickness figures removed.
FP Request to Classify 2001-2003 Mazda Protege ES in FP #27922cars addedaddedFP Mazda Protégé ES 2001–2003 newly classified at 2350–2468 lbs with 1991 cc DOHC four-cylinder, fuel injection, 11.0:1 compression, .450 in. valve lift limit.
T4 Clarification of On-Board Fire System for T2 #27183wordingwordingT2 must have fire system installed; T3 and T4 may have one per GCR 9.3.
T4 Mustang Ecoboost and GT Transmission #27439cars addedaddedT3 Ford Mustang EcoBoost gains three transmission gear ratio options.
T4 BRZ/FRS/86 Tire Size in T4 #27660tyres & wheels
T4 T4 RX8 Classification Error #27902cars addedaddedT3 and T4 Mazda RX-8 Base/R3 (04-12) reclassified to include Sport and GT variants.
T4 Request to add Toyota 86 GT to Spec Line #27910cars addedaddedToyota 86 GT variant (2017–) added to T3 and T4 spec lines.
FP Request to Correct Track of 1988-91 Honda Civic #27487otherotherFP and HP: 1988–91 Honda Civic and CRX track widths corrected to 61.3 / 61.7 inches across multiple levels.
FP Re-organize Prep2 Cylinder Head Rules for Clarity & Consistency #27661wordingwordingEP, FP, HP cylinder head rules reorganized for clarity; no performance change.
2:07.203Danny Steyn · fastest of 36 · top 5 within 1.8s
2:07.273Cliff Ira · fastest of 35 · top 5 within 1.4s
134.8Cliff Ira
2:02.938Gregory Eaton · fastest of 17 · top 5 within 0.8s
2:03.900James Jost · fastest of 16 · top 5 within 2.1s
153.9James Jost
-3.373squal -4.265s
97.3%qual 96.6%
2:11.257John Heinricy · fastest of 25 · top 5 within 0.2s
2:10.959Nick Leverone · fastest of 25 · top 5 within 0.6s
128.9Tommy Boileau
+3.686squal +4.054s
102.9%qual 103.2%
2:07.436Eric Prill · fastest of 19 · top 5 within 0.6s
2:08.076Eric Prill · fastest of 18 · top 5 within 0.8s
131.4Ken Kannard
+0.803squal +0.233s
100.6%qual 100.2%
39 rule changes (STL: 11, AS: 4, T4: 15, FP: 9)10 cars added · 5 engine · 4 weight · 3 suspension & brakes · 2 aero · 2 induction · 11 wording · 2 other · AS Spec Mustang (SMG) added as Restricted Prep class. · STL adds Mazda Spec MX-5 Challenge, 2000cc displacement, 2500 lb minimum weight, with mandatory Roush, Penske, Eibach, and other specified components. · FP and HP Austin-Healey Sprite Mk I / MG Midget may replace rear bodywork aft of cockpit with alternate material stock-appearing components. · EP Mazda MX-5 Global Cup classification updated to include 2019 model year. · Production classes: suspension rule clarified to specify spindles, hubs, bushings, bearings, and ball joints unrestricted. · Production carburetor and fuel injection rules clarified: permitted optional carburetors listed, Weber and auto-type substitutions specified, fuel injection throttle body and butterfly dimensions detailed, intake manifold port extension pr… · EP, FP, HP carburetors: jets, needles, metering rods, needle valves unrestricted; choke parts removable; stock or optional Weber 40 DCN permitted; Weber types, auto types listed. · T2, T3, T4 spare tire and cover removal wording clarified; removable covers now explicitly allowable to remove. · AS class ride height minimum clarified: five inches measured at rocker panel, excluding seams and stock effects. · EP Mazda MX-5/Miata model years expand from 1999-2002 to 1999-2005. · STU allows alternate intake manifolds on case-by-case basis; stock throttle device and manifold otherwise required. · AS Ford Mustang 79-93 non-Cobra drops 100 lbs to 3150; over 313 CID Cobra drops 100 lbs to 3450. · STL Acura/Honda B18 except C engine restrictor increased from 53mm to 54mm flat plate. · STL and STU ride height measurement clarified: lowest rocker panel point without driver, excluding pinch weld. · EP, FP, HP: clarified that tapered holes in ball joints can be reamed for bolt conversion, and wheel bearings and hubs unrestricted on all axles. · EP open cars may now use aftermarket hardtops if OEM-appearance and non-carbon-fiber; specific model allowances removed as redundant. · FP Dodge Daytona/Chrysler Laser 84-85 added at 2100 lbs; Shelby Charger/Omni 024 83-84 weight cut to 2100 lbs. · STL adds VW 1.8L R4 20VT 1781 cc, 1781 minimum weight, naturally aspirated only. · STL Mazda Renesis minimum weight reduced to 2700 lbs. · STL Mazda MX-5 Cup brake pad compound now open. · STL adds Acura/Honda B18C1 GSR with 1797cc displacement, 54mm flat plate restrictor required, porting outside 1" allowance prohibited. · STL Mazda 12 and 13B now permit port matching; porting ban removed. · T4 and T3 Mazda MX-5 hardtop rules clarified: any OEM or aftermarket top permitted if retaining OEM silhouette; specific part numbers listed. · T2, T3, T4 now allow any thermostat serving original equipment intent only. · T3 and T4 Mazda MX-5 Miata eligibility capped at 2016–2018 model years. · AS adds Spec Mustang SMG classification with 107.1 wheelbase, 3.73 gears, 355mm front and 300mm rear brakes. · STL B17 now requires 54mm flat plate restrictor; B18C Type R variants move to 54mm restrictor, weight chart baseline. · STL Mazda Miata removes maximum displacement limit; minimum weight corrected to unspecified figure. · T4 Celica GT wheelbase 2600 and 15x7 wheels added; Forte years narrowed; Fiesta ST starts 2014; Fiat 124 years 16-18 added; battery rule clarified. · T1–T4 spec car classifications clarified with permitted parts, rule conformance versions, and exclusions of other touring modifications. · T2–T4 subframe bushings now permitted to be replaced with non-spherical bushings of any material.showhide
AS Request to add SMG to 9.1.6.B.1 AS Intent #27140cars addedaddedAS Spec Mustang (SMG) added as Restricted Prep class.
STL Request to Classify Spec MX-5 Challenge in STL #27399cars addedaddedSTL adds Mazda Spec MX-5 Challenge, 2000cc displacement, 2500 lb minimum weight, with mandatory Roush, Penske, Eibach, and other specified components.
FP Request bodywork for Austin Healey Bugeye Sprite MK1 #27106aeroadded · aeroFP and HP Austin-Healey Sprite Mk I / MG Midget may replace rear bodywork aft of cockpit with alternate material stock-appearing components.
FP Request to classify the GMX5 2019 #27263cars addedaddedEP Mazda MX-5 Global Cup classification updated to include 2019 model year.
FP level one susp. component rule #27270wordingwordingProduction classes: suspension rule clarified to specify spindles, hubs, bushings, bearings, and ball joints unrestricted.
FP Clarification of Carb Rules - Prep 1 #27300wordingwordingProduction carburetor and fuel injection rules clarified: permitted optional carburetors listed, Weber and auto-type substitutions specified, fuel injection throttle body and butterfly dimensions detailed, intake manifold port extension pr…
FP Clarification of Carb Rules - Prep 2 #27301inductioninductionEP, FP, HP carburetors: jets, needles, metering rods, needle valves unrestricted; choke parts removable; stock or optional Weber 40 DCN permitted; Weber types, auto types listed.
T4 Request spare tire/wheel clarification #27012wordingfasterT2, T3, T4 spare tire and cover removal wording clarified; removable covers now explicitly allowable to remove.
AS Request Ride Height Clarification #26598wordingwordingAS class ride height minimum clarified: five inches measured at rocker panel, excluding seams and stock effects.
FP Request Miata Eligibility - 2003 #27121cars addedaddedEP Mazda MX-5/Miata model years expand from 1999-2002 to 1999-2005.
STL Request clarification for manifold and throttle in STU #27004wordingwordingSTU allows alternate intake manifolds on case-by-case basis; stock throttle device and manifold otherwise required.
AS Request to Revert to 2017 Weights #25885weightfaster · weightAS Ford Mustang 79-93 non-Cobra drops 100 lbs to 3150; over 313 CID Cobra drops 100 lbs to 3450.
STL Request Restrictor Plate correction #26779enginefaster · engineSTL Acura/Honda B18 except C engine restrictor increased from 53mm to 54mm flat plate.
T4 Request to allow piggy back ECU on 2000 Mazda Protégé #26085engine
T4 Request helper spring as optional #26678suspension & brakes
STL Request Ride Height Clarification #26597wordingwordingSTL and STU ride height measurement clarified: lowest rocker panel point without driver, excluding pinch weld.
FP Rollcenter Correction Clarification #25873wordingaddedEP, FP, HP: clarified that tapered holes in ball joints can be reamed for bolt conversion, and wheel bearings and hubs unrestricted on all axles.
FP Hardtops #26476aeroadded · aeroEP open cars may now use aftermarket hardtops if OEM-appearance and non-carbon-fiber; specific model allowances removed as redundant.
T4 Request to classify 2000 - 2001 BMW 323 #25096cars added
FP Request Classification of Dodge Daytona in F Production #26259weight -150 lbsfaster · weightFP Dodge Daytona/Chrysler Laser 84-85 added at 2100 lbs; Shelby Charger/Omni 024 83-84 weight cut to 2100 lbs.
STL Request to reduce weight of RX8 with Renesis rotary #25781weight -100 lbsfaster · weightSTL Mazda Renesis minimum weight reduced to 2700 lbs.
STL Request for Open Brake Pads On Mazda MX-5 Cup NC #25821otheraddedSTL Mazda MX-5 Cup brake pad compound now open.
STL Request to clarify B18C1 GSR Honda B motor table #26209cars addedaddedSTL adds Acura/Honda B18C1 GSR with 1797cc displacement, 54mm flat plate restrictor required, porting outside 1" allowance prohibited.
STL Port Matching #26415enginefaster · engineSTL Mazda 12 and 13B now permit port matching; porting ban removed.
T4 Correct Mazda MX-5 Hard Top Notes #26137wordingwordingT4 and T3 Mazda MX-5 hardtop rules clarified: any OEM or aftermarket top permitted if retaining OEM silhouette; specific part numbers listed.
T4 Consider opening class rules to allow any thermostat #26187engineadded · engineT2, T3, T4 now allow any thermostat serving original equipment intent only.
T4 Cap 2016 Mazda Miata year at 2018 #26388cars addedremoved · cars addedT3 and T4 Mazda MX-5 Miata eligibility capped at 2016–2018 model years.
AS SMG Mustang eligibility in American sedan #26224cars addedaddedAS adds Spec Mustang SMG classification with 107.1 wheelbase, 3.73 gears, 355mm front and 300mm rear brakes.
T4 2012-2015 Honda Civic Si Performance Request #26129suspension & brakes
STL Request to equalize FPR Reduction on all B-Series Vtec Engines #24746enginefaster · engineSTL B17 now requires 54mm flat plate restrictor; B18C Type R variants move to 54mm restrictor, weight chart baseline.
STL Request E&O for Mazda Miata Spec Line #25955otherunclearSTL Mazda Miata removes maximum displacement limit; minimum weight corrected to unspecified figure.
T4 Errors, Omissions, and Updates (Various) #22414wordingwordingT4 Celica GT wheelbase 2600 and 15x7 wheels added; Forte years narrowed; Fiesta ST starts 2014; Fiat 124 years 16-18 added; battery rule clarified.
T4 Request for Adjustments to fiat 124 specline #25371induction
T4 Add Clarification to Spec Car Classifications Vehicle Spec #25774wordingwordingT1–T4 spec car classifications clarified with permitted parts, rule conformance versions, and exclusions of other touring modifications.
T4 Clarify Subframe Bushings Permitted for T2-T4 #25800suspension & brakesadded · suspension & brakesT2–T4 subframe bushings now permitted to be replaced with non-spherical bushings of any material.
T4 Consider Solo SSC cross over classification into T4 #25802cars added
Every event the class ran, at any track, oldest to newest on the chart and newest first in the table. Each point is the class's best lap as a share of STL's best on the same day: the weather, the track and its configuration cancel out, so one figure compares across tracks and years where lap times cannot. It still moves when the yardstick's own balance changes or its field thins, and an event the yardstick did not run has no point. A best from fewer than three cars is greyed. The rule changes that took effect between two events are folded between their rows.