Quickest here:T2 1:51.198 Rylan Hazelton, Cal Club 2026 qualifying · T4 1:58.339 Oscar Jackson, Cal Club 2025 qualifying · AS 1:55.849 Roger Eagleton, Cal Club 2025 race
T2T4ASsolid race · dashed qualifying · slower is lower
T2T4ASsolid race · dashed qualifying · each class's best lap as a share of T2's at the same event (the reference class, changeable above); 100% is level, higher is quicker
Event
T2
T4
AS
Qual best
Race best
Trap
Qual best
Race best
Trap
vs T2
% of T2
Qual best
Race best
Trap
vs T2
% of T2
Cal Club 2026 CALCL262026-02-21
1:51.198Rylan Hazelton · fastest of 10 · top 5 within 2.5s-2.867s (-2.51%)
1:51.454Rylan Hazelton · fastest of 10 · top 5 within 3.0s-1.304s (-1.16%)
146.6Patrick Howe+32.2 mph (+28.1%)
2:01.678Izzy Sanchez · fastest of 5 · top 5 within 5.9s+3.339s (+2.82%)
2:01.157Izzy Sanchez · fastest of 5 · top 5 within 7.2s+1.235s (+1.03%)
135.5Izzy Sanchez+27.2 mph (+25.1%)
+9.703squal +10.480s
108.7%qual 109.4%
1:56.812Ross Murray · fastest of 2+0.367s (+0.32%)
1:56.314Ross Murray · fastest of 2+0.465s (+0.40%)
135.2Ross Murray+26.5 mph (+24.4%)
+4.860squal +5.614s
104.4%qual 105.0%
57 rule changes (T2: 27, T4: 19, AS: 11)8 cars added · 8 weight · 6 induction · 6 suspension & brakes · 4 tyres & wheels · 3 engine · 2 aero · 1 removed · 18 wording · 1 other · AS Chevy LS adds Edelbrock Performer RPM 71187 intake manifold with MSD 6014 ignition and 4776 Holly carburetor as spec line option. · BMW 435i (2014-2017) added to T2 with 40mm restrictor, 3400 lbs minimum weight. · Nissan Z including Nismo added to T2 with 38mm restrictor, 3600 lbs base and 3650 lbs Nismo. · T2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously prohibited except in specified examples. · T2-TCR adds Link & Co 03 TCR and MG6 TCR, both 3000 lbs, 90% power, 275 max tire width. · Ford Mustang V6 (05-14) removed from T4 Spec Lines. · T4 Mustang 4.0 V6 tire size increases from 245 to 255. · T2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously prohibited except in specified examples. · AS Ford Mustang Restricted Prep engines lose 3 mm restrictor plate, from 64 mm to 61 mm. · T2, T3, T4 cars may relocate under-dash electronics and fuse boxes for access after roll cage installation. · T2 Cadillac CT4-V Blackwing minimum weight drops 50 lbs to 3750. · T2 C6 Corvette LS2 restrictor increases from 67mm to 80mm FPR. · T2 Dodge Viper SRT10 coupe weight reduced from 3675 lbs to 3650 lbs. · T2 Ford Mustang GT 5.0L 15-23 permits Ford Track/Performance Package aero parts M-16600-FP and M-16601-MPP. · T4 Performance now permits 1-piece alternative rotors matching spec line sizes; alternate brake kits allowed same. · T2, T3, T4 cars may relocate under-dash electronics and fuse boxes for access after roll cage installation. · T4 Performance now permits 1-piece alternative rotors matching spec line sizes; alternate brake kits allowed same. · AS Ford Mustang GT 94-04 Restricted Prep Engine now permits Ford Motorsport M-6250-F303 camshaft. · T2 Ford Mustang Boss 302 restrictor opens 56mm to 63mm; Mustang GT 5.0L 60mm to 65mm. · T2 Chevrolet Camaro SS/1LE (10-15) minimum weight reduced to 3575 lbs. · T2 Ford Mustang Challenge Dark Horse R (2024-) weight increases to 3825 lbs, displacement grows to 5038cc, tire width expands to 315. · Dodge/Plymouth Neon ACR SOHC/DOHC 95-99 newly classified T4 at 2350 lbs minimum weight. · AS Cadillac CTS-V 04-07 Restricted Prep weight reduced 50 lbs to 3400. · T3 and T4 Mazda MX-5 Miata models add approved gear kit PT#-0000-02-6100 to notes. · T4 Mazda MX-5 Miata/Club/RF (19-24) and (16-18) remove discontinued hardtop part #0000-07-5901; T3 MX-5 Miata (16-18) and Global Cup ND (16-21) same. · T2 Spec Corvette to 3200 lbs; Mustang 11-14 restrictor 60→62mm; Mustang 2015-23 tyre 295→315; 996 weights down to 3050/3000 lbs; 997.2 models restrictor 60→65mm, weights reduced 50 lbs. · T2 Spec Corvette rev limit set to 7100 rpm. · T4 Mini Cooper S R53 02-06 gear ratios changed to 12.79, 7.79, 5.65, 4.62, 3.83, 3.13 or 11.42, 7.18, 5.39, 4.40, 3.65, 2.96. · Chevrolet Cobalt SS Sport Coupe 06-10 reinstated to T4 with 2384cc engine, 2628 restrictor, 2700 lbs minimum weight. · Mercedes C230 Kompressor 2002-2005 classified in T4 at 3240 lbs with 17-inch wheels and 300/290 mm brakes. · T3 and T4 Mazda MX-5 Miata models add approved gear kit PT#-0000-02-6100 to notes. · T4 Mazda MX-5 Miata/Club 16-18 wheel size changed to 17 x 7.5 inches. · T4 Mazda MX-5 Miata/Club/RF (19-24) and (16-18) remove discontinued hardtop part #0000-07-5901; T3 MX-5 Miata (16-18) and Global Cup ND (16-21) same. · T2, T3, T4 Spec Lines table header changed from T2 to ET. · BMW M2 CS Cup 2020 must run Red power stick part #8324085, not Purple #8324089. · T2 Chevrolet Corvette C5 Z06 and C6 brake allowances clarified; stock calipers and rotors only for C5, specific sizes for C6. · T2 Chevrolet Corvette C5 LS1 restrictor reduced from 59mm to 58mm FPR. · T2, T3, T4 Spec Lines table header changed from T2 to ET. · AS Ford Mustang GT 5.0 2018- weight reduced from 3600 to 3525 lbs. · T4 now permits B-Spec and C-Spec cars to compete in the class. · AS Ford Mustang GT 05-14 Restricted Prep Engine gains alternative gear ratios: 3.66, 2.43, 1.69, 1.32, 1.00, .65 · T4 Ford Mustang V6 05-14 weight drops from 3400 to 3300 lbs. · T4 Scion FR-S and Subaru BRZ Solo Spec allow any 200TW 225/45/17 or 215/45/17 DOT tire. · AS Ford Mustang GT 5.0L (15-17) flat plate restrictor reduced from 67mm to 64mm. · AS LS1/LS6 5.3L truck engine gains four approved intake part numbers: 12561269, 88894095, 89017363, 89017364. · T2 C6 Corvette LS2 restrictor increases from 63mm to 67mm FPR. · T2 Nissan 370Z max wheel size increases to 19 x 10.5 inches; mid link replacement for true coil overs now permitted. · T2 Cadillac CT4-V Blackwing maximum tire size increases from 295 to 315. · T4 Ford Mustang V6 05-14 allows GT 8.8 rear axle or 7.5 axle with 3.45:1 ratio. · T4 Ford Mustang V6 05-14 now permits OEM style rear deck spoiler similar to Laguna/CS packages. · AS Flotek Head plunge cut dimensions figure updated in GCR Section 9.1.6. · AS class notes cleanup: multiple Camaro, Firebird, CTS-V, Challenger, Mustang specs and fuel cell/ECM/head restrictions removed. · Ford Mustang Challenge Darkhorse R newly classified in T2 with 58 mm restrictor, 3775 lbs minimum weight. · T2 350Z (03-08) removes detailed OEM part numbers and consolidates permitted modifications into simplified allowance list. · AS Spec Lines removes ECM flexibility restriction from five Cadillac and Chevrolet/Pontiac V8 models. · T2 BMW M2 CS Cup requires Red power stick #8324085 instead of Purple #8324089; Corvette C5 Z06 restrictor reduces to 58mm from 59mm.showhide
AS Edelbrock manifold (& timing kit) to Chevy LS Spec Lines Request #39055cars addedcars addedAS Chevy LS adds Edelbrock Performer RPM 71187 intake manifold with MSD 6014 ignition and 4776 Holly carburetor as spec line option.
T2 Request to Add 2014-2017 435i to T2 #38991cars addedcars addedBMW 435i (2014-2017) added to T2 with 40mm restrictor, 3400 lbs minimum weight.
T2 Consideration for Nissan Z & NISMO Z to Touring 2 Class #39296cars addedcars addedNissan Z including Nismo added to T2 with 38mm restrictor, 3600 lbs base and 3650 lbs Nismo.
T2 Allow Alt Bushing Material in Toe Links #39607suspension & brakesfasterT2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously prohibited except in specified examples.
T2 Request for Classification of MG6 TCR in T2-TCR Class #39702cars addedcars addedT2-TCR adds Link & Co 03 TCR and MG6 TCR, both 3000 lbs, 90% power, 275 max tire width.
T4 T4 and T3 Feedback #39230removedremovedFord Mustang V6 (05-14) removed from T4 Spec Lines.
T4 T4 Mustang 4.0 #39489tyres & wheelsfasterT4 Mustang 4.0 V6 tire size increases from 245 to 255.
T4 Allow Alt Bushing Material in Toe Links #39607suspension & brakesfasterT2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously prohibited except in specified examples.
AS Restrictor Plate Change for Gen 2 Ford Coyote Engine #39501inductionslowerAS Ford Mustang Restricted Prep engines lose 3 mm restrictor plate, from 64 mm to 61 mm.
T2 Alternate Placement of Fuse Panel and Electronics Request #39370wordingwordingT2, T3, T4 cars may relocate under-dash electronics and fuse boxes for access after roll cage installation.
T2 Rebalance Blackwing Cadillac T2 for 2026 #39426weight -50 lbsfasterT2 Cadillac CT4-V Blackwing minimum weight drops 50 lbs to 3750.
T2 C6 LS2 Corvette Parity Request #39472inductionfasterT2 C6 Corvette LS2 restrictor increases from 67mm to 80mm FPR.
T2 T2 Tire Sizing #39490weight -25 lbsfasterT2 Dodge Viper SRT10 coupe weight reduced from 3675 lbs to 3650 lbs.
T2 Rear Spoiler for Mustang GT S550 (15-23) #39499aerounclearT2 Ford Mustang GT 5.0L 15-23 permits Ford Track/Performance Package aero parts M-16600-FP and M-16601-MPP.
T2 Clarify T4 Brake Rotor Allowance #39503suspension & brakessuspension & brakesT4 Performance now permits 1-piece alternative rotors matching spec line sizes; alternate brake kits allowed same.
T4 Alternate Placement of Fuse Panel and Electronics Request #39370wordingwordingT2, T3, T4 cars may relocate under-dash electronics and fuse boxes for access after roll cage installation.
T4 Clarify T4 Brake Rotor Allowance #39503suspension & brakessuspension & brakesT4 Performance now permits 1-piece alternative rotors matching spec line sizes; alternate brake kits allowed same.
AS 1994 Mustang Spec Line Request #39104wordingunclearAS Ford Mustang GT 94-04 Restricted Prep Engine now permits Ford Motorsport M-6250-F303 camshaft.
T2 Help the 2011-2014 s197Mustang GT and Boss302 Less Restriction #38523inductionfasterT2 Ford Mustang Boss 302 restrictor opens 56mm to 63mm; Mustang GT 5.0L 60mm to 65mm.
T2 Improving Competitiveness of Gen 5 Camaro SS #39021weight -50 lbsfasterT2 Chevrolet Camaro SS/1LE (10-15) minimum weight reduced to 3575 lbs.
T2 Adjust T2 Darkhorse R #39346weightslowerT2 Ford Mustang Challenge Dark Horse R (2024-) weight increases to 3825 lbs, displacement grows to 5038cc, tire width expands to 315.
AS Cadillac CTS-V BOP Weight Change #38640weight -50 lbsfasterAS Cadillac CTS-V 04-07 Restricted Prep weight reduced 50 lbs to 3400.
T2 ND Gearset Request for T4 #39166wordingwordingT3 and T4 Mazda MX-5 Miata models add approved gear kit PT#-0000-02-6100 to notes.
T2 ND Spec Lines Wrong PT#'s #39170wordingwordingT4 Mazda MX-5 Miata/Club/RF (19-24) and (16-18) remove discontinued hardtop part #0000-07-5901; T3 MX-5 Miata (16-18) and Global Cup ND (16-21) same.
T2 Touring 2 Post-Runoffs BOP Adjustments and Changes #39274weight -50 lbsfasterT2 Spec Corvette to 3200 lbs; Mustang 11-14 restrictor 60→62mm; Mustang 2015-23 tyre 295→315; 996 weights down to 3050/3000 lbs; 997.2 models restrictor 60→65mm, weights reduced 50 lbs.
T2 Adjust rev limit on Spec Corvette in T2 #39282engineslowerT2 Spec Corvette rev limit set to 7100 rpm.
T4 02-06 Mini Cooper Gear Ratios #38966wordingunclearT4 Mini Cooper S R53 02-06 gear ratios changed to 12.79, 7.79, 5.65, 4.62, 3.83, 3.13 or 11.42, 7.18, 5.39, 4.40, 3.65, 2.96.
T4 Reinstatement of the 2005-2010 Cobalt into T4 #38987cars addedcars addedChevrolet Cobalt SS Sport Coupe 06-10 reinstated to T4 with 2384cc engine, 2628 restrictor, 2700 lbs minimum weight.
T4 Request to Classify Mercedes C230K #39080cars addedcars addedMercedes C230 Kompressor 2002-2005 classified in T4 at 3240 lbs with 17-inch wheels and 300/290 mm brakes.
T4 ND Gearset Request for T4 #39166wordingwordingT3 and T4 Mazda MX-5 Miata models add approved gear kit PT#-0000-02-6100 to notes.
T4 E&O wheel size on ND #39168tyres & wheelsunclearT4 Mazda MX-5 Miata/Club 16-18 wheel size changed to 17 x 7.5 inches.
T4 ND Spec Lines Wrong PT#'s #39170wordingwordingT4 Mazda MX-5 Miata/Club/RF (19-24) and (16-18) remove discontinued hardtop part #0000-07-5901; T3 MX-5 Miata (16-18) and Global Cup ND (16-21) same.
T2 Incorrect Touring Heading #38451wordingwordingT2, T3, T4 Spec Lines table header changed from T2 to ET.
T2 Clarifications needed to BMW M2 CS cup line #38536engineunclearBMW M2 CS Cup 2020 must run Red power stick part #8324085, not Purple #8324089.
T2 Fix brake allowance supersessions. #38554suspension & brakesslowerT2 Chevrolet Corvette C5 Z06 and C6 brake allowances clarified; stock calipers and rotors only for C5, specific sizes for C6.
T2 C5 Corvette correction #38782engineslowerT2 Chevrolet Corvette C5 LS1 restrictor reduced from 59mm to 58mm FPR.
T4 Incorrect Touring Heading #38451wordingwordingT2, T3, T4 Spec Lines table header changed from T2 to ET.
AS RE: Previous Letter 37695 Update #38245weight -75 lbsfasterAS Ford Mustang GT 5.0 2018- weight reduced from 3600 to 3525 lbs.
T4 Allow B-Spec cars to run in T4 #38439wordingwordingT4 now permits B-Spec and C-Spec cars to compete in the class.
AS Errors and Omissions #38234wordingwordingAS Ford Mustang GT 05-14 Restricted Prep Engine gains alternative gear ratios: 3.66, 2.43, 1.69, 1.32, 1.00, .65
T4 T4 Mustang #38059weight -100 lbsfasterT4 Ford Mustang V6 05-14 weight drops from 3400 to 3300 lbs.
T4 SSC tire allowance #38216tyres & wheelstyres & wheelsT4 Scion FR-S and Subaru BRZ Solo Spec allow any 200TW 225/45/17 or 215/45/17 DOT tire.
AS Errors and Omission #38055inductionslowerAS Ford Mustang GT 5.0L (15-17) flat plate restrictor reduced from 67mm to 64mm.
AS Request to Add LS1/LS6 Intakes for 5.3L Truck Engine EnO #38197wordingwordingAS LS1/LS6 5.3L truck engine gains four approved intake part numbers: 12561269, 88894095, 89017363, 89017364.
T2 C6 T-2 Corvette 6 Liter Engine Restrictor #37490inductionfasterT2 C6 Corvette LS2 restrictor increases from 63mm to 67mm FPR.
T2 370Z Mid link Replacement for True Coil Overs and OEM Wheel Size #38014suspension & brakesfasterT2 Nissan 370Z max wheel size increases to 19 x 10.5 inches; mid link replacement for true coil overs now permitted.
T2 T2 Cadillac tire #38210tyres & wheelsfasterT2 Cadillac CT4-V Blackwing maximum tire size increases from 295 to 315.
T4 Correct Ring and Pinion Ratio to T3, Sorry I Mean T4 3.7 V6 Stang #38041wordingwordingT4 Ford Mustang V6 05-14 allows GT 8.8 rear axle or 7.5 axle with 3.45:1 ratio.
T4 T4 Mustang #38058aeroaeroT4 Ford Mustang V6 05-14 now permits OEM style rear deck spoiler similar to Laguna/CS packages.
AS Flotek Head Plunge Cut Inconsistencies #37502wordingunclearAS Flotek Head plunge cut dimensions figure updated in GCR Section 9.1.6.
AS Notes clean up #37693wordingwordingAS class notes cleanup: multiple Camaro, Firebird, CTS-V, Challenger, Mustang specs and fuel cell/ECM/head restrictions removed.
T2 Please class the Darkhorse R in T2 #37295cars addedcars addedFord Mustang Challenge Darkhorse R newly classified in T2 with 58 mm restrictor, 3775 lbs minimum weight.
T2 T2 350Z Spec Line Cleanup #37603wordingwordingT2 350Z (03-08) removes detailed OEM part numbers and consolidates permitted modifications into simplified allowance list.
AS Race memo #37902wordingunclearAS Spec Lines removes ECM flexibility restriction from five Cadillac and Chevrolet/Pontiac V8 models.
T2 T2 BOP #37312otherslowerT2 BMW M2 CS Cup requires Red power stick #8324085 instead of Purple #8324089; Corvette C5 Z06 restrictor reduces to 58mm from 59mm.
Cal Club 2025 CALCL252025-02-22
1:54.065Oli Thordarson · fastest of 2
1:52.758Oli Thordarson · fastest of 2
114.4Oli Thordarson
1:58.339Oscar Jackson · fastest of 5 · top 5 within 8.3s
1:59.922Oscar Jackson · fastest of 4 · top 4 within 7.3s
108.4Tony Kiratsous
+7.164squal +4.274s
106.4%qual 103.7%
1:56.445Roger Eagleton · fastest of 3 · top 3 within 4.0s
1:55.849Roger Eagleton · fastest of 4 · top 4 within 5.3s
108.7Roger Eagleton
+3.091squal +2.380s
102.7%qual 102.1%
142 rule changes (T2: 61, T4: 62, AS: 19)23 weight · 21 cars added · 13 suspension & brakes · 11 tyres & wheels · 7 induction · 6 engine · 3 aero · 3 removed · 46 wording · 9 other · T2 Mustang GT 5.0L combines 2015-17 and 2018-23 with different restrictors: 63mm for Gen 2, 60mm for Gen 3. · T2 Chevrolet Camaro 1LE gains 100 lbs to 3600, restrictor increases to 62mm FPR. · T2 BMW M235iR (-2016) now permits oil cooler, radiator per touring rules, and silicone charge pipe. · Ford SCCA Club Spec Mustang classified T3 at 3350 lbs with driver; Mazda SCCA Club Spec MX-5 classified T4 at 2500 lbs with driver. · T4 Ford Mustang V6 (05-14) final drive set to 3.45, GT/CS front bumper cover permitted with front fascia. · Ford SCCA Club Spec Mustang classified T3 at 3350 lbs with driver; Mazda SCCA Club Spec MX-5 classified T4 at 2500 lbs with driver. · AS Ford Mustang Coyote engines increase restrictor to 80mm from 64mm or 67mm. · AS Mustang GT 05-14 4.6L loses 300 lbs; 15-17 and 2018+ models lose 61mm and 60mm restrictors respectively. · AS class gear ratio options specified for multiple American muscle cars, including Cadillac CTS-V, Chevrolet Camaro, Ford Mustang, Dodge Challenger, and Pontiac GTO. · AS LS-engine cars gain ECU freedom; Camaro/Firebird 93-02 LS1 removes fuel cell location restriction. · T2, T3, T4 remove nine, nine, and thirty-six expired spec lines respectively, effective 2025-01-01. · T2 Ford Mustang GT 5.0L (11-14) weight reduced from 3575 to 3525 lbs. · T2 Spec Corvette clarifies braking, tires, cooling, suspension, and Spec+ upgrades; SC-3200, SC+-3300 lbs. · T2, T3, T4 remove nine, nine, and thirty-six expired spec lines respectively, effective 2025-01-01. · T4 2016-2018 Mazda Miata MX-5 minimum weight reduced to 2575 lbs from 2650 lbs. · T2 and T3 Mustang spec lines remove redundant driveshaft alternate/aluminum allowance wording. · T2 Chevrolet Corvette C6 LS3 restrictor increases from 53mm to 56mm flat plate. · T2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors. · T2, T3, T4 brake component wording clarified: 2-piece rotors allowed in T2 within 5% OE diameter, T3 within 2% OEM diameter. · T2, T3, T4 fuel cell cars may remove charcoal canisters, emissions valves, and sensors. · Porsche Spec Boxster moves to T4, minimum weight 2750 lbs, requires 3 Super Tour events before Runoffs eligibility. · T2 Chevrolet Corvette C6 Coupe/Grand Sport wheels widened to 18×11 or 19×13. · T4 BMW 320i 14-15 Spec Line expires 12/31/24 removed; Turner Motorsports intercooler #024703TMS02 allowed. · Cadillac CTS 02-07 3.6L classified in T3. · T2 Corvette C5 Z06 restrictor split by engine: LS1 59mm, LS2 63mm, LS3 56mm FPR. · T2 Chevrolet Corvette Z06 (06-12) Spec Line deleted entirely. · T2 and T3 Mustang spec lines remove redundant driveshaft alternate/aluminum allowance wording. · T4 Mini Cooper S R53 now allows Alta 15% Pulley #AMPENG20X. · T4 removes restriction on aftermarket wheel weight minimum of 15 lbs. · T2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors. · Mazda 3 (19-24) newly classified in T4 at 2850 lbs with 17×8 wheels and 245 tires. · T2, T3, T4 brake component wording clarified: 2-piece rotors allowed in T2 within 5% OE diameter, T3 within 2% OEM diameter. · T2, T3, T4 fuel cell cars may remove charcoal canisters, emissions valves, and sensors. · T3 and T4 Mazda RX-8 and MX-5 permit transmission kit #0000-02-5700. · Porsche Spec Boxster moves to T4, minimum weight 2750 lbs, requires 3 Super Tour events before Runoffs eligibility. · Ford Mustang V6 (05-14) newly classified to T4 with 50mm restrictor, 3400 lbs minimum weight. · T4 BMW 320i 14-15 Spec Line expires 12/31/24 removed; Turner Motorsports intercooler #024703TMS02 allowed. · Unable to summarize: rule changes specified in letter #37281, not provided. · Cadillac CTS 02-07 3.6L classified in T3. · T4 Honda Civic Si 06-11 minimum weight drops 50 lbs to 2900, restrictor clarified. · T4 NC MX-5 06-15 removes SM5 suspension allowance, clarifies Mazda Motorsports LSD part number, adds weight penalty for other LSDs. · T4 Mazda MX-5 Miata/Club (16-18) wheel size changes to 17 x 7.5 inches. · T4 Mazda RX-8 gets 59mm restrictor and 3200 lbs; MX-5 Club drops to 2550 lbs. · T4 Mazda MX5 Miata/Club/RF 19-24 wheel size changes to 17 x 7.5. · T2 Spec Corvette now allows 295 R compound DOT tires as alternative to Nankang NS-2R. · T4 Honda Civic Si 06-11 permitted to use LSD per category rules. · AS Ford Mustang GT models gain alternate transmission ratio options for 2024-09-01. · T2 Corvette C6 LS2 restrictor increases to 63mm; Camaro 1LE weight drops to 3500 lbs, restrictor tightens to 58mm FRP. · T2 Subaru Impreza WRX STi (03-07) and (08-11) expiration notes removed. · T2 Ford Mustang 5.0L gets 100 lb weight reduction with 4-piston Brembo brakes and 355mm rotors; EcoBoost brake note removed. · T4 Chevrolet Camaro V-6 (96-02) weight reduced from 3250 lbs to 3150 lbs. · T4 Mazda MX-5 Miata/Club 16-18 drops 50 lbs to 2650; 19-24 RF drops 50 lbs to 2750. · Ford Mustang GT 5.0L and V6 now permit Track/Performance Package parts in T2 and T3. · T2 Ford Mustang S550 5.0 Gen2/Gen3 gains 100 lbs with stock or Brembo 355mm brakes. · T2-T4 Ford Mustangs: remove 25 lbs penalty for non-OEM driveshaft, clarify alternate driveshaft allowances. · T2 Corvette C5, Camaro SS, Firebird, Solstice GXP, C6 allow four or six piston front calipers. · Audi S4 (2000-2002) moves to T3 with 3400 lbs minimum weight, 38mm turbo inlet restrictor required. · Ford Mustang GT 5.0L and V6 now permit Track/Performance Package parts in T2 and T3. · Mercedes C300 4Matic 2008-2011 homologated to T4 at 3,725 lbs with 18x8.5 wheels, 245 max tires, 3.27 final drive. · T2-T4 Ford Mustangs: remove 25 lbs penalty for non-OEM driveshaft, clarify alternate driveshaft allowances. · T4 Mini Cooper S (02-04) deleted; (05-06) model year corrected to R53; (07-13) R56 simplified specs; (2014-2023) added with spring rates. · T4 OEM intake chambers, resonators and acoustic devices may be removed if ports sealed and before restrictor. · Audi S4 (2000-2002) moves to T3 with 3400 lbs minimum weight, 38mm turbo inlet restrictor required. · AS Ford Mustang GT 5.0L (2018-) classified at 3600 lbs with 60mm restrictor, Brembo BBK permitted. · T4 Mazda MX-5 Club 06-15 now permits OEM front spoiler NF51-V4-900F. · T4 Ford Mustang V6 (05-10) weight reduced 50 lbs to 3225. · T4 Mini Cooper S 02-04 and 05-06 now allow Milltek exhaust manifold #SSXM459 and 25mm rear sway bar. · AS Chevrolet Camaro 1LE (2016-) classified with 3600 lbs minimum weight, 60mm restrictor, 275 tires. · AS Chevrolet/Pontiac Camaro & Firebird 82-92 5.7L LS1 classified at 3200 lbs with 65mm restrictor plate required. · AS Chevrolet Camaro, Firebird, and Ford Mustang models permitted to use Flo Tek cylinder heads. · T3 and T4 Mazda RX-8 may remove or disable factory oil injection system. · T2 BMW M3 01-06 max wheel size increases from 18 x 9 to 18 x 10 inch. · T2, T3, T4 driveshafts may use alternative materials or one-piece units; non-OEM adds 25 lbs. · T3 and T4 Mazda RX-8 may remove or disable factory oil injection system. · T4 Mazda MX5 Miata/Club/RF year range extended to 2024, suspension package permitted with 100 lbs weight increase. · T4 Volkswagen Rabbit 2.5 (06-09) front brakes increase from 228 to 288 vented disc. · T2, T3, T4 driveshafts may use alternative materials or one-piece units; non-OEM adds 25 lbs. · T4 Mazda MX-5 Miata/Club 16-18 removes differential stock requirement, allows up to 500lb front and 300lb rear springs. · AS Camaro/Firebird and GTO LS1 connecting rods approved: Callies CSC6100DS6A2AH, Scat 2-1CR6100-944, GM 12649190. · AS Cadillac CTS-V, Chevrolet Camaro SS, Dodge Challenger, Ford Mustang GT, Pontiac GTO allowed 11" wheels until 3/1/25. · T2 Porsche Cayman S 06-09 allows StopTech ST60/ST40 brake kit with 50 lb penalty. · T4 Mazda RX-8 allows Mazdaspeed radiator, coil spring kit, OE rear spoiler, front air dam, springs to 700 lb front/400 lb rear, oil metering pump bypass, sway bars to 32 mm front/19 mm rear. · Chevrolet Camaro, Pontiac Firebird 70-81 Full Prep classified AS at 3400-3600 lbs with 250 lb weight reduction. · AS class: multiple cars gain fuel cell placement note allowing 24 inches from standard tank, unrestricted filler location. · Chevrolet Camaro 16- Full Prep classified into AS at 3400 lbs with 250 lb weight reduction. · AS adds Ford Mustang GT 05-14 Restricted prep Engine with 62mm FPR, 3400 lbs minimum, 18-inch wheels. · T2-T4 Spec Lines remove wheelbase requirement, replace with Required Restrictor specification. · T2 and T3 Nissan 370Z brake rotors enlarged: front 320x28 to 355x32mm, rear 320x16 to 350x20mm vented. · T2 Mustang GT 5.0L 2018+ now permits BMR rear upper control arm camber links part #UTCA064. · T2-T4 Spec Lines remove wheelbase requirement, replace with Required Restrictor specification. · T4 Mazda RX-8 rear spring opens to any 400lb, was specific part numbers only. · T2 and T3 Nissan 370Z brake rotors enlarged: front 320x28 to 355x32mm, rear 320x16 to 350x20mm vented. · T2 Mustang GT 5.0L 15-17 now permits BMR rear upper control arm camber links part #UTCA064. · T2 Chevrolet Camaro SS, 1LE, Corvette C5/C6, Z06, and Pontiac Firebird, Solstice GXP now allow four or six piston front calipers. · T2 Cadillac CT4-V Blackwing Runoffs qualification requirement removed. · T2, T3, T4 battery replacement wording simplified; OEM weight tolerance requirement removed. · T4 now permits C-Spec cars to compete alongside B-Spec cars. · T2-T4 spec lines for 46 cars expire 12/31/24; appeal required to continue. · T2 Chevrolet Camaro 1LE minimum weight increases to 3575 lbs, restrictor plate widens to 60mm. · T2, T3, T4 battery replacement wording simplified; OEM weight tolerance requirement removed. · T4 Mazda MX-5 Miata/Club (16-18) and (19-21) permitted to replace 3rd and 4th gears with specific parts. · T4 now permits C-Spec cars to compete alongside B-Spec cars. · T2-T4 spec lines for 46 cars expire 12/31/24; appeal required to continue. · T2 Cadillac CT4-V Blackwing rear wheels widen from 18 x 10 to 18 x 11. · T2 BMW M2 CS Cup drops 50 lbs to 3550; M235iR drops 50 lbs to 3300. · T2 Spec Corvette minimum weight drops 175 lbs to 3200, tire rules tighten to Nankang NS-2R only. · T2 Dodge Viper SRT-10 rear tyre narrowed from 345/30 to 335/30. · T2 Ford Mustang GT 5.0L three generations gain 50-75 lbs minimum weight; restrictors increase to 58-60mm. · T2 Chevrolet Camaro 1LE minimum weight drops 50 lbs to 3500, restrictor opens to 58mm flat plate. · T2 C5 Z06 removes restrictor note from weight; C5/C6 Corvettes increase restrictors to 59mm, 63mm LS2, 53mm LS3. · T3 Nissan 370Z model years expanded to include NISMO Edition through 2022. · T4 Mazda MX-5 ND1 minimum weight increases 50 lbs to 2700; suspension springs now allow up to 500 lb front, 300 lb rear. · T4 BRZ/FRS/86 spring allowance clarified: 225 lb front and 300 lb rear springs permitted; non-OEM LSD allowed with +50 lbs penalty. · T4 Acura TSX 2004-2008 now allows header. · T3 Nissan 370Z model years expanded to include NISMO Edition through 2022. · T2 BMW M2 CS Cup 2020- permitted to add hood vents conforming to 9.1.9.2.D.8.a.7. · T4 Mercedes Benz CLK 320 Coupe model years expand to 2000-2007, C320 Sedan added. · AS crate motor part number specified: GM Performance CT400 P/N 19370604 engine assembly for GM vehicles. · AS Spec Lines Ford Mustang GT 5.0L (15-17) max wheel size increases to 19.0 inches. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 now permits SPC-66045 alternate front upper control arms. · AS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front brake caliper adapters for updated or backdated components. · T2 Chevrolet Corvette C6 LS2 restrictor plate increases from 58mm to 60mm flat plate. · T2 Cadillac CT4-V Blackwing permitted to use Radium fuel surge tank behind fireproof bulkhead. · T3 Mazda RX-8 removes transmission/final drive pairing requirement; T4 removes same requirement, adds Mazdaspeed radiator and coil spring kit. · T3 BMW 320i (14-15) gains aftermarket intercooler permission; T4 loses it. · T3 Pontiac Solstice GXP minimum ride height set to 3 inches. · T3 Mazda RX-8 removes transmission/final drive pairing requirement; T4 removes same requirement, adds Mazdaspeed radiator and coil spring kit. · T3 BMW 320i (14-15) gains aftermarket intercooler permission; T4 loses it. · T3 Pontiac Solstice GXP minimum ride height set to 3 inches. · T2 Nissan 370Z allows NISMO suspension alternatives to SPL parts; rear toe arms removed from permitted list. · T4 Mini Cooper S R53 loses 50 lbs, to 2700 for both 02-04 and 05-06 model years. · T2 Porsche Cayman S model year range extended from 06-08 to 06-09. · T4 Mini Cooper S all years now run 17-inch wheels, up from 16, with wider rims to 8 inches. · T4 Volkswagen Rabbit 2.5 (06-09) consolidates 06-07 and 08-09 models; Integrated Engineering intake allowed with 25lb penalty. · T4 Audi A4 2.8 V6 wheels grow to 17x8, tyres to 245, springs now 800lb with 32mm sway bars. · T2 Chevrolet Corvette C5 Z06 restrictor increases from 53mm to 56mm; 58mm option removed. · T2 upper and lower control arm bushings can now use polyurethane, delrin, or alternate synthetic materials. · T2 Cadillac CT4-V Blackwing now permits adjustable sway bar end links. · Acura TSX 2004-2008 newly classified in T4 at 3000 lbs minimum weight with 2354cc engine. · T4 Mustang rear sway bar increases from 22mm to 28mm permitted. · T2 Honda Civic Type-R tire size increases from 275 to 295. · T3 BMW 320I now permitted to use aftermarket intercooler.showhide
T2 Mustang Update backdate #37275inductionunclearT2 Mustang GT 5.0L combines 2015-17 and 2018-23 with different restrictors: 63mm for Gen 2, 60mm for Gen 3.
T2 BOP Adjustment for 2016 - Camaro SS/1LE #37434weight +100 lbsslowerT2 Chevrolet Camaro 1LE gains 100 lbs to 3600, restrictor increases to 62mm FPR.
T2 BMW M235iR TCS CHANGE REQUEST #37470wordingwordingT2 BMW M235iR (-2016) now permits oil cooler, radiator per touring rules, and silicone charge pipe.
T2 Request to Classify Club Spec in Appropriate Touring Classes #37523cars addedcars addedFord SCCA Club Spec Mustang classified T3 at 3350 lbs with driver; Mazda SCCA Club Spec MX-5 classified T4 at 2500 lbs with driver.
T4 Ford Mustang V6 (05-14) #37516wordingwordingT4 Ford Mustang V6 (05-14) final drive set to 3.45, GT/CS front bumper cover permitted with front fascia.
T4 Request to Classify Club Spec in Appropriate Touring Classes #37523cars addedcars addedFord SCCA Club Spec Mustang classified T3 at 3350 lbs with driver; Mazda SCCA Club Spec MX-5 classified T4 at 2500 lbs with driver.
AS Increase Coyote Engine Restrictor to 80mm #36177inductionfasterAS Ford Mustang Coyote engines increase restrictor to 80mm from 64mm or 67mm.
AS Performance Pack for 2015+ Mustang #36867enginefasterAS Mustang GT 05-14 4.6L loses 300 lbs; 15-17 and 2018+ models lose 61mm and 60mm restrictors respectively.
AS Gear Ratios #37131wordingwordingAS class gear ratio options specified for multiple American muscle cars, including Cadillac CTS-V, Chevrolet Camaro, Ford Mustang, Dodge Challenger, and Pontiac GTO.
AS ECU specs for LS engine #37208enginefasterAS LS-engine cars gain ECU freedom; Camaro/Firebird 93-02 LS1 removes fuel cell location restriction.
T2 Remove spec lines that have expired #37269removedremovedT2, T3, T4 remove nine, nine, and thirty-six expired spec lines respectively, effective 2025-01-01.
T2 BoP for the Various Mustangs #37185weight -50 lbsfasterT2 Ford Mustang GT 5.0L (11-14) weight reduced from 3575 to 3525 lbs.
T2 Spec Corvette Line Clarification. #37441wordingwordingT2 Spec Corvette clarifies braking, tires, cooling, suspension, and Spec+ upgrades; SC-3200, SC+-3300 lbs.
T4 Remove spec lines that have expired #37269removedremovedT2, T3, T4 remove nine, nine, and thirty-six expired spec lines respectively, effective 2025-01-01.
T2 Redundant Verbiage Regarding Mustang Spec Lines for Driveshaft #36484wordingwordingT2 and T3 Mustang spec lines remove redundant driveshaft alternate/aluminum allowance wording.
T2 Request Less Restriction for Ls-3 Engined C6 Corvette #36810inductionfasterT2 Chevrolet Corvette C6 LS3 restrictor increases from 53mm to 56mm flat plate.
T2 Fuel Emissions Components #37076wordingwordingT2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors.
T2 fix brake wording #37129wordingwordingT2, T3, T4 brake component wording clarified: 2-piece rotors allowed in T2 within 5% OE diameter, T3 within 2% OEM diameter.
T2 Evaporative emissions systems #37130wordingwordingT2, T3, T4 fuel cell cars may remove charcoal canisters, emissions valves, and sensors.
T2 Move Spec Boxster to T4 #37158cars addedcars addedPorsche Spec Boxster moves to T4, minimum weight 2750 lbs, requires 3 Super Tour events before Runoffs eligibility.
T2 Corvette Wheels #37169tyres & wheelsfasterT2 Chevrolet Corvette C6 Coupe/Grand Sport wheels widened to 18×11 or 19×13.
T2 BMW 320i Spec Line #37204wordingwordingT4 BMW 320i 14-15 Spec Line expires 12/31/24 removed; Turner Motorsports intercooler #024703TMS02 allowed.
T2 Classification for a 2005 Cadillac CTS 3.6 liter 6 speed manual #37224cars addedcars addedCadillac CTS 02-07 3.6L classified in T3.
T2 Please Consider Allowing Update to the C5 Corvette #37298engineunclearT2 Corvette C5 Z06 restrictor split by engine: LS1 59mm, LS2 63mm, LS3 56mm FPR.
T2 Major error in lane, but nobody ran it. #37302removedremovedT2 Chevrolet Corvette Z06 (06-12) Spec Line deleted entirely.
T4 Redundant Verbiage Regarding Mustang Spec Lines for Driveshaft #36484wordingwordingT2 and T3 Mustang spec lines remove redundant driveshaft alternate/aluminum allowance wording.
T4 R53 Mini Cooper S Weight Reduction Request #36612enginefasterT4 Mini Cooper S R53 now allows Alta 15% Pulley #AMPENG20X.
T4 Allowable Wheel Offset #36855wordingwordingT4 removes restriction on aftermarket wheel weight minimum of 15 lbs.
T4 Fuel Emissions Components #37076wordingwordingT2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors.
T4 2019-2024 Mazda 3 for T4 #37077cars addedcars addedMazda 3 (19-24) newly classified in T4 at 2850 lbs with 17×8 wheels and 245 tires.
T4 fix brake wording #37129wordingwordingT2, T3, T4 brake component wording clarified: 2-piece rotors allowed in T2 within 5% OE diameter, T3 within 2% OEM diameter.
T4 Evaporative emissions systems #37130wordingwordingT2, T3, T4 fuel cell cars may remove charcoal canisters, emissions valves, and sensors.
T4 Allow Spec MX5 upgrade kit for 2009-11 RX8 S2 Transmision #37140wordingwordingT3 and T4 Mazda RX-8 and MX-5 permit transmission kit #0000-02-5700.
T4 Move Spec Boxster to T4 #37158cars addedcars addedPorsche Spec Boxster moves to T4, minimum weight 2750 lbs, requires 3 Super Tour events before Runoffs eligibility.
T4 3.7 Mustangs to T4 #37188cars addedcars addedFord Mustang V6 (05-14) newly classified to T4 with 50mm restrictor, 3400 lbs minimum weight.
T4 BMW 320i Spec Line #37204wordingwordingT4 BMW 320i 14-15 Spec Line expires 12/31/24 removed; Turner Motorsports intercooler #024703TMS02 allowed.
T4 MX5 2006-2015 NC Help #37221otherunclearUnable to summarize: rule changes specified in letter #37281, not provided.
T4 Classification for a 2005 Cadillac CTS 3.6 liter 6 speed manual #37224cars addedcars addedCadillac CTS 02-07 3.6L classified in T3.
T4 Civic SI in T4 #37248weight -50 lbsfasterT4 Honda Civic Si 06-11 minimum weight drops 50 lbs to 2900, restrictor clarified.
T4 2006-2015 T4 NC Mx5 spec line #37278wordingwordingT4 NC MX-5 06-15 removes SM5 suspension allowance, clarifies Mazda Motorsports LSD part number, adds weight penalty for other LSDs.
T4 ND MX-5 wheel allowance #37279tyres & wheelsunclearT4 Mazda MX-5 Miata/Club (16-18) wheel size changes to 17 x 7.5 inches.
T4 T4 BOP #37281weight +75 lbsslowerT4 Mazda RX-8 gets 59mm restrictor and 3200 lbs; MX-5 Club drops to 2550 lbs.
T4 Allow 7.5 #37286tyres & wheelstyres & wheelsT4 Mazda MX5 Miata/Club/RF 19-24 wheel size changes to 17 x 7.5.
T2 Spec Corvette Change for T2 #37127tyres & wheelstyres & wheelsT2 Spec Corvette now allows 295 R compound DOT tires as alternative to Nankang NS-2R.
T4 Bop Request 06-11 Honda Civic Si #37013wordingwordingT4 Honda Civic Si 06-11 permitted to use LSD per category rules.
AS Mustang transmission ratios #36662wordingunclearAS Ford Mustang GT models gain alternate transmission ratio options for 2024-09-01.
T2 Errors #36214other -75 lbsunclearT2 Corvette C6 LS2 restrictor increases to 63mm; Camaro 1LE weight drops to 3500 lbs, restrictor tightens to 58mm FRP.
T2 Subaru Appeal #36258wordingwordingT2 Subaru Impreza WRX STi (03-07) and (08-11) expiration notes removed.
T2 S550 Brakes #36571otherfasterT2 Ford Mustang 5.0L gets 100 lb weight reduction with 4-piston Brembo brakes and 355mm rotors; EcoBoost brake note removed.
T4 T4 Camaro V6 weight reduction #36232weightfasterT4 Chevrolet Camaro V-6 (96-02) weight reduced from 3250 lbs to 3150 lbs.
T4 BOP adjustment for ND MX5s #36345weight -50 lbsfasterT4 Mazda MX-5 Miata/Club 16-18 drops 50 lbs to 2650; 19-24 RF drops 50 lbs to 2750.
T2 Mustang T2/T3 #35877wordingunclearFord Mustang GT 5.0L and V6 now permit Track/Performance Package parts in T2 and T3.
T2 S550 Brakes #35926weightslowerT2 Ford Mustang S550 5.0 Gen2/Gen3 gains 100 lbs with stock or Brembo 355mm brakes.
T2 T2-T4 Driveshaft Mistake...? #36050weightfasterT2-T4 Ford Mustangs: remove 25 lbs penalty for non-OEM driveshaft, clarify alternate driveshaft allowances.
T2 request for allowance of 6 piston calipers for T2 C5 corvettes #36126suspension & brakesfasterT2 Corvette C5, Camaro SS, Firebird, Solstice GXP, C6 allow four or six piston front calipers.
T2 B8/8.5 Audi S4 T3 and T2 #36195cars addedcars addedAudi S4 (2000-2002) moves to T3 with 3400 lbs minimum weight, 38mm turbo inlet restrictor required.
T4 Mustang T2/T3 #35877wordingunclearFord Mustang GT 5.0L and V6 now permit Track/Performance Package parts in T2 and T3.
T4 Homologation of car to T4 #36030cars addedcars addedMercedes C300 4Matic 2008-2011 homologated to T4 at 3,725 lbs with 18x8.5 wheels, 245 max tires, 3.27 final drive.
T4 T2-T4 Driveshaft Mistake...? #36050weightfasterT2-T4 Ford Mustangs: remove 25 lbs penalty for non-OEM driveshaft, clarify alternate driveshaft allowances.
T4 MINI Cooper S Spec Lines Corrections. #36086wordingwordingT4 Mini Cooper S (02-04) deleted; (05-06) model year corrected to R53; (07-13) R56 simplified specs; (2014-2023) added with spring rates.
T4 Allow Removal of Sound Tubes #36130inductionfasterT4 OEM intake chambers, resonators and acoustic devices may be removed if ports sealed and before restrictor.
T4 B8/8.5 Audi S4 T3 and T2 #36195cars addedcars addedAudi S4 (2000-2002) moves to T3 with 3400 lbs minimum weight, 38mm turbo inlet restrictor required.
AS Request for Classification of 2018-2023 mustang In #35764cars addedcars addedAS Ford Mustang GT 5.0L (2018-) classified at 3600 lbs with 60mm restrictor, Brembo BBK permitted.
T4 Allow OEM Front Spoiler 06-08 Miata in T4 #35941aerofasterT4 Mazda MX-5 Club 06-15 now permits OEM front spoiler NF51-V4-900F.
T4 T4 Mustang Weight Reduction In T4 Spec #36051weight -50 lbsfasterT4 Ford Mustang V6 (05-10) weight reduced 50 lbs to 3225.
T4 R53 Mini Cooper S spec line request In #36056otherfasterT4 Mini Cooper S 02-04 and 05-06 now allow Milltek exhaust manifold #SSXM459 and 25mm rear sway bar.
AS 6th gen Camaro limited prep #35733cars addedcars addedAS Chevrolet Camaro 1LE (2016-) classified with 3600 lbs minimum weight, 60mm restrictor, 275 tires.
AS Chevrolet/Pontiac Camaro & Firebird (82-92) 5.7L V8 LS1 Alum BLK #35825cars addedcars addedAS Chevrolet/Pontiac Camaro & Firebird 82-92 5.7L LS1 classified at 3200 lbs with 65mm restrictor plate required.
AS Full Prep Head #35891otherotherAS Chevrolet Camaro, Firebird, and Ford Mustang models permitted to use Flo Tek cylinder heads.
T2 Allow T4 and T3 RX8 to Disable/Remove Factory Oil Inj. #35761engineunclearT3 and T4 Mazda RX-8 may remove or disable factory oil injection system.
T2 Competition Adjustment Request/Wheel Size of E46 #35895tyres & wheelsfasterT2 BMW M3 01-06 max wheel size increases from 18 x 9 to 18 x 10 inch.
T2 Driveshafts #35916weightslowerT2, T3, T4 driveshafts may use alternative materials or one-piece units; non-OEM adds 25 lbs.
T4 Allow T4 and T3 RX8 to Disable/Remove Factory Oil Inj. #35761engineunclearT3 and T4 Mazda RX-8 may remove or disable factory oil injection system.
T4 2023 ND2 Miata Classification and Allowances #35837weightslowerT4 Mazda MX5 Miata/Club/RF year range extended to 2024, suspension package permitted with 100 lbs weight increase.
T4 Errors and Omissions for 06-09 VW Rabbit Rotor #35851suspension & brakesfasterT4 Volkswagen Rabbit 2.5 (06-09) front brakes increase from 228 to 288 vented disc.
T4 Driveshafts #35916weightslowerT2, T3, T4 driveshafts may use alternative materials or one-piece units; non-OEM adds 25 lbs.
T4 GCR ERROR - letter not properly applied to GCR #35999suspension & brakesfasterT4 Mazda MX-5 Miata/Club 16-18 removes differential stock requirement, allows up to 500lb front and 300lb rear springs.
AS Restricted Prep Aftermarket Parts Request #35682wordingwordingAS Camaro/Firebird and GTO LS1 connecting rods approved: Callies CSC6100DS6A2AH, Scat 2-1CR6100-944, GM 12649190.
AS Allowance of 11 #35824tyres & wheelsfasterAS Cadillac CTS-V, Chevrolet Camaro SS, Dodge Challenger, Ford Mustang GT, Pontiac GTO allowed 11" wheels until 3/1/25.
T2 Brake Request for 2009 Porsche Cayman #35723suspension & brakesslowerT2 Porsche Cayman S 06-09 allows StopTech ST60/ST40 brake kit with 50 lb penalty.
T4 Corrections to T4 RX8 Spec line #35767wordingwordingT4 Mazda RX-8 allows Mazdaspeed radiator, coil spring kit, OE rear spoiler, front air dam, springs to 700 lb front/400 lb rear, oil metering pump bypass, sway bars to 32 mm front/19 mm rear.
AS Request to Classify 1970-1981 Camaro and Firebird in AS #33659cars addedcars addedChevrolet Camaro, Pontiac Firebird 70-81 Full Prep classified AS at 3400-3600 lbs with 250 lb weight reduction.
AS Fuel Cell 12 #34194wordingwordingAS class: multiple cars gain fuel cell placement note allowing 24 inches from standard tank, unrestricted filler location.
AS Please Classify the 6th Gen Into AS. #35448cars addedcars addedChevrolet Camaro 16- Full Prep classified into AS at 3400 lbs with 250 lb weight reduction.
AS spec lines #35713cars addedcars addedAS adds Ford Mustang GT 05-14 Restricted prep Engine with 62mm FPR, 3400 lbs minimum, 18-inch wheels.
T4 Allow any 400lb rear spring in the RX8 #35433suspension & brakessuspension & brakesT4 Mazda RX-8 rear spring opens to any 400lb, was specific part numbers only.
T4 370Z Brake Rotor Size Correction #35487suspension & brakessuspension & brakesT2 and T3 Nissan 370Z brake rotors enlarged: front 320x28 to 355x32mm, rear 320x16 to 350x20mm vented.
T2 2015+ Mustang Sway Bar and A-Arm Request #35154suspension & brakessuspension & brakesT2 Mustang GT 5.0L 15-17 now permits BMR rear upper control arm camber links part #UTCA064.
T2 Brake Kits #35245otherotherT2 Chevrolet Camaro SS, 1LE, Corvette C5/C6, Z06, and Pontiac Firebird, Solstice GXP now allow four or six piston front calipers.
T2 Runoffs wording on Caddy in T2 #35377wordingwordingT2 Cadillac CT4-V Blackwing Runoffs qualification requirement removed.
T2 More Car Lightening Stuff #35319weightfasterT2, T3, T4 battery replacement wording simplified; OEM weight tolerance requirement removed.
T2 Inclusion of B-C spec cars in T4 #35374cars addedcars addedT4 now permits C-Spec cars to compete alongside B-Spec cars.
T2 T2-T4 Set expiration dates on spec lines #35378wordingwordingT2-T4 spec lines for 46 cars expire 12/31/24; appeal required to continue.
T2 Reply to letter #35161 and #31661 #35384weight +75 lbsslowerT2 Chevrolet Camaro 1LE minimum weight increases to 3575 lbs, restrictor plate widens to 60mm.
T4 More Car Lightening Stuff #35319weightfasterT2, T3, T4 battery replacement wording simplified; OEM weight tolerance requirement removed.
T4 ND Missed Items #35352wordingwordingT4 Mazda MX-5 Miata/Club (16-18) and (19-21) permitted to replace 3rd and 4th gears with specific parts.
T4 Inclusion of B-C spec cars in T4 #35374cars addedcars addedT4 now permits C-Spec cars to compete alongside B-Spec cars.
T4 T2-T4 Set expiration dates on spec lines #35378wordingwordingT2-T4 spec lines for 46 cars expire 12/31/24; appeal required to continue.
T2 Rebalance Blackwing Cadillac T2 #35079tyres & wheelsfasterT2 Cadillac CT4-V Blackwing rear wheels widen from 18 x 10 to 18 x 11.
T2 M2 CS RACING #35130weight -50 lbsfasterT2 BMW M2 CS Cup drops 50 lbs to 3550; M235iR drops 50 lbs to 3300.
T2 Spec Corvette in T2 #35139weight -175 lbsfasterT2 Spec Corvette minimum weight drops 175 lbs to 3200, tire rules tighten to Nankang NS-2R only.
T2 T2 Viper BoP #35155tyres & wheelsslowerT2 Dodge Viper SRT-10 rear tyre narrowed from 345/30 to 335/30.
T2 BOP Adjustment for 5.0L Mustangs #35156weight +75 lbsslowerT2 Ford Mustang GT 5.0L three generations gain 50-75 lbs minimum weight; restrictors increase to 58-60mm.
T2 Take at Look at T-2 BOP #35161weight -50 lbsfasterT2 Chevrolet Camaro 1LE minimum weight drops 50 lbs to 3500, restrictor opens to 58mm flat plate.
T2 C5 Corvette Spec Line Oversight #35169inductionfasterT2 C5 Z06 removes restrictor note from weight; C5/C6 Corvettes increase restrictors to 59mm, 63mm LS2, 53mm LS3.
T2 Requested Update of Model Years of 370Z #35231wordingwordingT3 Nissan 370Z model years expanded to include NISMO Edition through 2022.
T4 Mazda MX-5 ND1 Spec Line Request #34232weight +50 lbsslowerT4 Mazda MX-5 ND1 minimum weight increases 50 lbs to 2700; suspension springs now allow up to 500 lb front, 300 lb rear.
T4 BRZ/FRS/86 Spring Allowance #35038wordingwordingT4 BRZ/FRS/86 spring allowance clarified: 225 lb front and 300 lb rear springs permitted; non-OEM LSD allowed with +50 lbs penalty.
T4 TSX Allowance #35219aerofasterT4 Acura TSX 2004-2008 now allows header.
T4 Requested Update of Model Years of 370Z #35231wordingwordingT3 Nissan 370Z model years expanded to include NISMO Edition through 2022.
T2 M2 CS RACING #35122aeroaeroT2 BMW M2 CS Cup 2020- permitted to add hood vents conforming to 9.1.9.2.D.8.a.7.
T4 Inclusion of similar car. (CLK 320) #34626cars addedcars addedT4 Mercedes Benz CLK 320 Coupe model years expand to 2000-2007, C320 Sedan added.
AS Crate Motor Part Numbers #32944wordingwordingAS crate motor part number specified: GM Performance CT400 P/N 19370604 engine assembly for GM vehicles.
AS Request wheel size change #33007tyres & wheelsfasterAS Spec Lines Ford Mustang GT 5.0L (15-17) max wheel size increases to 19.0 inches.
AS Alternative Upper Front Control Arms for Dodge Challenger #33352wordingwordingAS Dodge Challenger 5.7L/6.1L/6.4L V8 now permits SPC-66045 alternate front upper control arms.
AS Front Brake Caliper Adapters for Dodge Challenger #33353wordingwordingAS Dodge Challenger 5.7L/6.1L/6.4L V8 allows alternate front brake caliper adapters for updated or backdated components.
T2 Corvette LS2 Restrictor Plate Adjustment #34456inductionfasterT2 Chevrolet Corvette C6 LS2 restrictor plate increases from 58mm to 60mm flat plate.
T2 Blacking Cadillac Fuel Capacity #34624wordingwordingT2 Cadillac CT4-V Blackwing permitted to use Radium fuel surge tank behind fireproof bulkhead.
T2 Rules Clarification for Mazda RX8 Spec Line #34395wordingwordingT3 Mazda RX-8 removes transmission/final drive pairing requirement; T4 removes same requirement, adds Mazdaspeed radiator and coil spring kit.
T2 rule book corrections #34437otherfasterT3 BMW 320i (14-15) gains aftermarket intercooler permission; T4 loses it.
T2 Ride Height Correction for the T3 Solstice. #34615wordingwordingT3 Pontiac Solstice GXP minimum ride height set to 3 inches.
T4 Rules Clarification for Mazda RX8 Spec Line #34395wordingwordingT3 Mazda RX-8 removes transmission/final drive pairing requirement; T4 removes same requirement, adds Mazdaspeed radiator and coil spring kit.
T4 rule book corrections #34437otherfasterT3 BMW 320i (14-15) gains aftermarket intercooler permission; T4 loses it.
T4 Ride Height Correction for the T3 Solstice. #34615wordingwordingT3 Pontiac Solstice GXP minimum ride height set to 3 inches.
T2 370Z Obsolete Parts & NISMO Alternatives to SPL Parts #34297wordingwordingT2 Nissan 370Z allows NISMO suspension alternatives to SPL parts; rear toe arms removed from permitted list.
T4 2002-2006 Mini Cooper S R53 Spec Line Request #34336weight -50 lbsfasterT4 Mini Cooper S R53 loses 50 lbs, to 2700 for both 02-04 and 05-06 model years.
T2 2009 Porsche Cayman Classing Request #34147wordingwordingT2 Porsche Cayman S model year range extended from 06-08 to 06-09.
T4 05-06 Mini Wheel Weight #34112tyres & wheelsfasterT4 Mini Cooper S all years now run 17-inch wheels, up from 16, with wider rims to 8 inches.
T4 96-01 Audi a4 2.8 Spring Rate #34217suspension & brakesfasterT4 Audi A4 2.8 V6 wheels grow to 17x8, tyres to 245, springs now 800lb with 32mm sway bars.
T2 C5 Z06 Straight Line Speed #33575inductionslowerT2 Chevrolet Corvette C5 Z06 restrictor increases from 53mm to 56mm; 58mm option removed.
T2 Allowance of any nonmetallic bushing material in T2 #33833suspension & brakessuspension & brakesT2 upper and lower control arm bushings can now use polyurethane, delrin, or alternate synthetic materials.
T2 Allow Adjustable stabilizer bar links #33861suspension & brakessuspension & brakesT2 Cadillac CT4-V Blackwing now permits adjustable sway bar end links.
T4 Request to Classify 2004-2008 Acura TSX in T4 #33590cars addedcars addedAcura TSX 2004-2008 newly classified in T4 at 3000 lbs minimum weight with 2354cc engine.
T4 T4 Mustang Brakes/Swaybar #34036suspension & brakesfasterT4 Mustang rear sway bar increases from 22mm to 28mm permitted.
T2 Honda Civic Type R Tire Size Increase #33672tyres & wheelsfasterT2 Honda Civic Type-R tire size increases from 275 to 295.
T4 BMW 320I intercooler #33762otherfasterT3 BMW 320I now permitted to use aftermarket intercooler.
Cal Club 2023 CALCL232023-02-24
250 earlier rule changes on record, in force before Cal Club 2023 (from 2019)44 weight · 42 cars added · 36 suspension & brakes · 13 tyres & wheels · 10 aero · 7 engine · 7 induction · 82 wording · 9 other · T2 C5 Corvette permitted GM Motorsports T1 suspension package and SpecCorvette SCT-1 swaybars. · T2/T3 Mustang GT 5.0L and V6 (11-14) may remove upper grille fog lights, replace with mesh or screen. · T4 Mazda MX-5 ND2 (19-21) classified: 1998cc, 2309mm wheelbase, 225 max tires, 2800 lbs. · T2/T3 Mustang GT 5.0L and V6 (11-14) may remove upper grille fog lights, replace with mesh or screen. · T4 Mazda MX-5 Club Model 06-15 Mazda Motorsports LSD part number corrected from 32655 to 0000-02-5564. · T2 BMW M235iR weight reduced 50 lbs to 3350, aftermarket shocks now allowed. · T5 class added as regional-only; T5 tyres maximum width 225, minimum aspect ratio 45. · T2-T5 Touring front and rear suspension maximum negative camber changed to 3.5 degrees. · T4 Honda Civic Si 06-11 now permits 32mm sway bars front and rear and 700 pound springs. · T5 class added as regional-only; T5 tyres maximum width 225, minimum aspect ratio 45. · T2-T5 Touring front and rear suspension maximum negative camber changed to 3.5 degrees. · T2 Dodge Viper SRT-10 wheel size 18x11 rear, weight to 3675 lbs, throttle restrictor hole 44mm convertible or 42mm hardtop. · T4 Ford Mustang V6 (05-10) wheels widen to 18x9, front brakes grow to 314mm vented, weight drops to 3275 lbs. · T4 Mazda MX-5 Club (06-15) minimum weight drops 25 lbs to 2600; Mazda LSD #32655 now permitted without penalty. · T3 Subaru BRZ 2022- minimum weight up to 2975 lbs; spring rate to 1000 F/R, brake parts allowed without penalty. · AS allows Hoosier W2 tyre option in addition to R7, R6, WET/H20. · AS Dodge Challenger 08-20 adds two transmission ratio options: 2.97, 2.10, 1.45, 1.00, 0.74, 0.50 or 2.26, 1.58, 1.19, 1.00, 0.77, 0.63. · T4 Mazda3 04-09 now permits Corksport balance shaft delete kit GEN-6-504-10. · AS Cadillac CTS-V 6.0L V8 removes 50 lbs weight penalty for 295 tire size. · T2 BMW M235iR/M240iR: 240iR/Evo package now permitted without 50 lb penalty; Evo package clarified to 75 lbs. · T2 BMW E92 M3 (08-14) permitted to use Fall Line Suspension arms from G8X/F8x/E9x M3, E9x M3/E82 1M. · T4 Hyundai Tiburon V-6 wheel width increases from 7 to 8 inches at 17-inch diameter. · T2-T4 Touring cars with alternative springs may use performance top hats with spherical bearings on shocks and struts. · T2 BMW E92 M3 (08-14) note reference changed from 77 to 78. · Cadillac CT4-V Blackwing (2022+) classified in T2 at 3800 lbs with 94 x 85.6mm engine. · T4 Mazda3 i 2.0L added as spec line with 1999cc displacement and 2425 lbs minimum weight. · T2-T4 Touring cars with alternative springs may use performance top hats with spherical bearings on shocks and struts. · T2-T4 cars model year 2018+ may use non-OEM ECU with 75 lb weight penalty via spec line adjustment. · BMW M2 CS Cup 2020- now permits specific exhaust part #18302459928 and hot country package cooling parts. · 2022+ Cadillac CT4-V Blackwing classified in T2 at 3564cc, 3800 lbs, 18×10/11 wheels, 295 MT tires. · T2-T4 cars model year 2018+ may use non-OEM ECU with 75 lb weight penalty via spec line adjustment. · T4 Nissan Sentra SE-R Spec V 02-06 now permits balance shaft removal kit OQR25-NOBAL. · T4 BMW 323 (98-00) wheelbase increases to 2725 mm, final drive ratio changes to 3.07. · T4 Mazda RX-8 04-12 gains Eibach spring alternatives to Mazda Motorsports springs front and rear. · T4 Mazda3 04-09 tire size increases from 235 to 245. · T4 Ford Mustang V6 05-10 shock part numbers corrected to 8741-1494SPORT front and 8241-1240SPORT rear. · T4 Scion FR-S and Subaru BRZ Solo Spec Coupes updated to 2020 specifications Rev 7/20. · T4 2016–18 Mazda MX-5 Miata/Club gains 100 lbs. for approved suspension package with specific springs. · T2-T4 grill openings may remove non-metallic webbed false sections; 16 square inch limit removed. · T2 Chevrolet Corvette C6 LS2 restrictor increases from 56mm to 58mm. · T2-T4 grill openings may remove non-metallic webbed false sections; 16 square inch limit removed. · T3 Spec Lines Subaru BRZ TS (13-21) added to class specification wording. · T2 BMW Z4M 06-08 weight reduced from 3150 to 3100 lbs. · T4 Mazda MX-5 Club 06-15 allows non-OEM LSD with +50 lbs penalty; removes stock transmission and differential requirements. · T4 2005-2010 Ford Mustang V6 now specifies Koni damper part numbers 8741.1494 front and 8741.1240 rear. · SMG long tube headers: Borla PN 17237 discontinued, Kooks PN 11312000 and American Racing PN MT3-05134300LSNC approved alternatives. · AS Mercury Capri (79-86) removed as individual spec line, merged into Ford Mustang (79-93) spec line. · AS Spec Mustang SMG loses 3.73 gear ratio and 355/300 mm brake specification. · AS Chevrolet, Pontiac, Ford full prep engines now permit alternate cylinder heads with restrictor plate ALL26180 and 1.250 inserts ALL26186 for regional competition. · T2 Dodge Viper SRT-10 loses 50 lbs to 3550; throttle restrictor hole shrinks from 43mm to 41mm. · T2-T4 clarified: grill opening area may increase max 16 sq in for radiator cooling only, retaining factory mesh shape. · T2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted. · T2, T3, T4 clarify that spec lines listing permitted or allowed parts are alternatives to category rules, not replacements. · T2 Spec Mustang model designation changed to Ford Spec Mustang. · T2-T4 clarified: grill opening area may increase max 16 sq in for radiator cooling only, retaining factory mesh shape. · T4 BMW 323 98-00 minimum weight drops to 3250 lbs, 50mm restrictor removed. · T4 Honda Civic Si consolidates 12-13 and 14-15 into single 12-15 spec line with updated suspension allowances. · T2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted. · T2, T3, T4 clarify that spec lines listing permitted or allowed parts are alternatives to category rules, not replacements. · T4 Acura RSX/RSX Type-S 02-06 removes requirement that original wheels must remain stock. · T4 Chevrolet Camaro V-6 (96-02) removes requirement that shock/struts, mounts, and transmission differential remain stock. · T2 BMW M2 CS Cup 2020 rear brake rotor reduced from 390 mm to 380 mm. · Nissan Sentra SE-R Spec V (2007–2012) newly classified in T4 at 3000 lbs minimum weight. · T4 Mazda RX-8 04-12 allows alternate sway bars max 32mm front, 19mm rear; removes 60mm restrictor requirement. · T4 BMW 320i (14-15) now allows GFB T9357 aluminum diverter valve. · T4 Honda Civic FWD gets wider 8-inch wheels, 245 tyres max, and sway bar allowances to 29mm front, 22mm rear. · T4 multiple cars: Volkswagen Rabbit 2.5 (08-09) to 2675 lbs; Mazda MX-5/Club (06-15) to 2625 lbs; RX-8 to 3125 lbs; Honda/Acura/Chevy/Mazda wheel widths 7 to 8 inches. · T4 Volkswagen Passat, Jetta 1.8T adds 2014 model year to eligible years. · BMW M2 (2017+) added to T2 with 2979cc engine, 10.5x18 wheels, 295 tires, 3650 lbs weight. · Porsche 911 997.2 GTS (09-12) classified in T2 at 3400 lbs with 60mm flat plate restrictor required. · T4 Volkswagen Passat, Jetta 1.8T adds 2014 model year to eligible years. · AS Chevrolet/Pontiac Camaro & Firebird 93-02 now allow BMR AA004 or UMI 2310 adjustable front upper control arms. · AS Pontiac GTO 04-06 LS1 to 3300 lbs, LS2 to 3350 lbs on 295 tire. · T2 BMW M2 CS Cup 2020- must run Purple power stick, part #8324089 instead of #TBD. · T2 Porsche 911/997.1 (06-08) now allows alternate Cargraphics CARP97DFIFKR exhaust manifold. · T2 BMW M2 CS Cup 2020- weight increases from 3625 to 3600 lbs; mandatory Purple power stick added. · T4 BMW 320i 14-15 part number corrected from 20121.140 to E10-20-031-01-22. · AS Cadillac CTS-V 6.0L V8 removes 50 lbs tire size penalty, making it lighter. · AS consolidates seven SN95 Mustang spec lines into three: 94-04 including Cobra, 94-95 5.0/5.8, and 96-04 4.6L two/four valve. · AS Camaro/Firebird LT1/LS1 transmission code changes to 6362; Mustang GT 4.6L/5spd changes to 5.0L/6spd with 300 lbs weight reduction. · AS Camaro/Firebird and Mustang GT gear ratio specifications restored with alternate sets permitted. · AS Chevrolet Camaro & Firebird, Ford Mustang variants, Mercury Capri minimum weights increase 50 lbs across all model years. · T3 Honda Civic Type-R 2020+ allows brake rotor 45251-TGH-A01 with 25 lb penalty. · T2 Ford Mustang GT 5.0L 15-17 restrictor grows 55mm to 58mm; 2018- grows 53mm to 55mm. · T2 BMW Z4M 06-08 weight increases from 3100 to 3150 lbs. · T2 BMW E92M3 08-14 weight drops 50 lbs to 3425, intake restrictor reduces 3mm to 77mm. · T3 Honda Civic Type-R 2020+ allows brake rotor 45251-TGH-A01 with 25 lb penalty. · T2 C5 and C6 Corvettes permit specific dry sump kits and minor air dam trimming up to 3.9 cm depth. · T2 Chevrolet Camaro 1LE auto trans gets new gear ratios and 2.77 final drive ratio. · T2 BMW M3 01-06 minimum competition weight drops 100 lbs to 3000. · T2 Chevrolet Camaro SS/1LE model years expanded from 2010–2014 to 2010–2015. · T4 Mini Cooper S (02-04, 05-06) suspension/wheel rules simplified; (07-13) gear ratios changed to 3.31, 2.13, 1.48, 1.14, 0.95, 0.82, final drive to 3.65, brakes to 280 mm. · T4 Ford Mustang V6 05-10 now allows cold air intake. · T2-T4 clutch disc and pressure plate must be at least 95% of factory OEM weight. · Spec Corvette newly classified in T2 at 3375 lbs with 53mm restrictor and 3.75" minimum ride height required. · T2 BMW E92 M3 front and rear springs increased to 1000 lbs/in from 800. · T2 Toyota Supra 2020- spring rates limited to 800# front and 1000# rear maximum. · T2-T4 clutch disc and pressure plate must be at least 95% of factory OEM weight. · AS Mustang 4.6L/5spd loses 300 lbs; 5.0L/6spd gains 56mm restrictor requirement. · AS CTS-V LS6 and LS2 may now use Driveshaft Shop carbon fiber driveshaft for durability. · AS Chevrolet Camaro SS V8 6.2L model years extended from 10-13 to 10-15. · T2 BMW M2 CS Cup 2020- permitted to remove door glass and mechanism. · T4 Ford Mustang V6 05-10 wheels increase from 17 to 18 inches. · T2 BMW M235iR allows 240iR/Evo package with 50 lb penalty, must run DOT tires. · Toyota Supra 2020- newly classified in T2 at 3450 lbs minimum weight with 295 tire and 19-inch wheels. · T2 Honda Civic Type-R gains allowance for PRL cold air intake #PRL PRL-HCR-INT-HVI. · T2 Porsche Carrera S 997.2 (06-08) weight reduced 50 lbs to 3225. · T2 Ford Mustang GT 5.0L (15-17) gear ratios corrected to 3.66, 2.43, 1.69, 1.32, 1.00, 0.65 or 4.17, 2.34, 1.52, 1.14, 0.87, 0.69. · T2 BMW Z4M 06-08 maximum wheel size increases from 18x9 to 18x10 inches. · T2 BMW M2 CS Cup 2020- and M235iR clarify homologation notes for DOT tires and BMW Motorsports components. · Toyota Supra 2020- newly classified in T2 at 3450 lbs minimum weight with 295 tire and 19-inch wheels. · T4 Mazda MX-5 durability rule now applies to T2-T4 instead of T2-T3 only. · T4 Chevrolet Sonic (2011-) spec clarified: 28mm TIR restrictor placement, PCV plug requirement, and allowed suspension parts listed. · T4 Mazda MX-5 06-15 removes front and rear end links from suspension package spec. · T4 BMW Z4 2.5L (03-05) minimum weight reduced from 3100 to 3050 lbs. · T4 2016+ Mazda MX-5 Miata gains allowance for 29mm front and 16mm rear sway bars. · T4 Scion FR-S, Subaru BRZ, and Toyota 86 replace Eibach part 4.10582.880 with 82105.320, 4.10582 and SPC 67660. · T4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.45 or 3.55 ratio at +25 lb penalty. · Ford Mustang GT 5.0L 15-17 Restricted Preparation classified in AS with 55mm flat plate restrictor required. · 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 10-13 275 tire removed; Challenger 08-20 gains 315 tire option at 3600 lbs. · AS Camaro & Firebird (93-02) and Mustang GT (05-14) specifications restored with 200 lb weight reduction for permitted heads. · BMW M2 CS Cup 2020+ classified in T2 at 3625 lbs with 2979cc engine, 10.5x18 wheels, 295 tires. · T2 and T3 Nissan 350Z and 370Z permit 44011-RC350 rear caliper kit and SZ350 rotors. · T4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.55 final drive, adds 25 lb penalty. · T3 and T4 FR-S, 86, and BRZ year ranges capped: T3 at 2021, T4 at 2017-2021. · BMW M2 CS Cup 2020+ classified in T2 at 3625 lbs with 2979cc engine, 10.5x18 wheels, 295 tires. · T3 and T4 Mazda MX-5 06-15 now allow Mazda Transmission kit part # 0000-02-5700. · T4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.55 final drive, adds 25 lb penalty. · T3 and T4 FR-S, 86, and BRZ year ranges capped: T3 at 2021, T4 at 2017-2021. · AS Dodge Challenger 08-20 gains 6.1L and 6.4L V8 options; 5.7L weight rises to 3500 lbs on 295 tyres, 3600 on 315 tyres. · AS Camaro/Firebird (93-02) and Mustang Coupe GT (05-14) consolidated into single specs with 100 lb and 300 lb weight reductions respectively. · T2 BMW E92 M3 (08-14) weight reduced 50 lbs to 3475, with detailed brake, spring, sway bar, and restrictor specs. · T2 Corvette C5 Z06 restrictor sizes increase to 53mm and 58mm; C6 LS2 to 56mm, LS3 to 50mm; Camaro SS/1LE weight drops 75 lbs to 3625; 2016+ Camaro restrictor to 56mm; Mustang GT 11-14 to 58mm, 15-17 to 55mm, 2018+ to 53mm; Viper SRT-10 th… · T3 Alfa Romeo 4C Launch Edition now allowed in Spec Lines. · T3 Alfa Romeo 4C Launch Edition now allowed in Spec Lines. · T2 Ford Mustang GT 5.0L and Ecoboost 2.3 sway bar part numbers added to notes. · T2 brake rotors expand from ferrous metal only to 2-piece ferrous disks with aluminum hats, within 5% OE diameter. · T2 Corvette C-5 Z06 loses 50 lbs to 3425; Camaro SS/1LE loses 50 lbs to 3650; Mustang GT and Boss 302 gain 275 to 295 tyres. · T2 Porsche Cayman S, Spyder (10-12) allows 800#/in front and 1000#/in rear springs, cooler ducting, rotor ducting, and specific Porsche and StopTech brake items. · AS Dodge Challenger 5.7L V8 gets iron block requirement, 10.5:1 compression max, intake valve 12.7 mm, exhaust 12.3 mm, intake duration 188°, exhaust duration 205°. · AS Dodge Challenger 08-14 rear spoiler part number changes from 1GL20RXF to 1GL20TZZAB. · T2 Ford Mustang EcoBoost and GT 5.0L gain three optional gear ratio sets for competition use. · T4 Scion FRS and Subaru BRZ Solo Spec Coupe final drive ratio changed from 4.30 to 4.10. · AS class pursues specified list of eligible tires; details of tire changes not provided in letter. · AS class pursuing specified list of eligible tires; details pending further communication. · No restrictor plate change implemented; 2021 AS Mustang Coyote under evaluation. · AS 2005-2009 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 reclassified to AS; full preparation classification approved effective 2020-07-01. · AS class cylinder head replacement options under review; implementation planned for 2021 season. · AS Mustang, Camaro, Firebird, Capri max brake rotor diameter increases from 12.2 to 13.1 inches. · AS rotor diameter increase approved; see Fastrack letter #28748 for details. · Cannot read: letter references external document #27663 not provided. · T2 Porsche Cayman S, Spyder (10-12) gains brake, suspension, and drivetrain upgrades: StopTech calipers, 800#/in front and 1000#/in rear springs, Porsche control arms, PDK allowed. · T4 Mazda RX-8 04-12 now allows OE rear spoiler #F151-V4-920F and OE front air dam #F151-V4-900f-BB. · T4 2006-2015 Mazda MX-5 Club Model now allows non-stock wheels; transmission, differential, LSD remain stock. · Cannot read: letter references external document #27663 not provided. · 2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine and Eibach PN# 2563.140 springs allowed. · T1 and T2 Corvettes may convert leaf spring suspension to coilover with 800 lb max spring rate allowed. · 2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine and Eibach PN# 2563.140 springs allowed. · AS Chevrolet/Pontiac Camaro & Firebird (82-92) loses 50 lbs, to 3500. · T2 BMW E92 M3 08-14 gains approved AP Racing brake kit part numbers 13.01.10038 front, 13.01.10053 rear. · T2 Chevrolet Corvette C5 Z06 loses 50 lbs with 45mm restrictor, to 3175; 50 lbs with 55mm restrictor, to 3350. · T3 BMW Z3 M & Coupe 1998-1999 weight reduced from 3350 to 3150 lbs. · T4 06-15 Mazda MX-5 now allows header part numbers 0000-06-5407 or 0000-06-5407-NC. · T3 BMW Z3 M & Coupe 1998-1999 weight reduced from 3350 to 3150 lbs. · T2 Porsche 911 997.2 allows GT3 Cup front fascia with 75 lb penalty; OEM rear deck lid and GT3 Cup splitter now required or prohibited. · T2 Ford Mustang GT 5.0L 15-17 transmission gear ratios corrected to two allowed options. · T2 Porsche 911/997 (06-08, 09-12, Carrera S 06-08) aero rules relaxed; 997.2 adds 60mm restrictor and PDK +100lbs option. · T4 Honda Civic Si 12-13 and 14-15 now allow H&R and HPD springs up to 700 pounds with 47mm restrictor. · T4 Ford Mustang V6 05-10 springs now permitted max 500 lbs front and 400 lbs rear. · 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 200 lb weight reduction, up from 150 lb. · 05-10 Ford Mustang Coupe GT 4.6L OHC classified AS with 3200 lbs minimum weight, HR cam restricted prep. · AS 10-15 Chevrolet Camaro Full Prep classified with 3400 lbs base weight, over 313 CID engine 3700 lbs maximum. · Pontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18 x 9.5 inches, Sky weight drops to 3200 lbs. · T2 cars now allowed to use ferrous metal 2-piece brake rotors within 5% of OE diameter. · Mazda RX-8 Base/R3/Sport/GT (04-12) classified in T3 effective 2020-02-01. · T2 Nissan 370Z gains alternative Stoptech brake kit option with 50 lb weight penalty. · T2 Ford Mustang Ecoboost 2.3 loses 100 lbs to 3400, wheels widen to 19 x 11, intercooler TIR increases to 50mm. · T2 Mustang GT5.0L gets 19x11 wheels instead of 18x11, Brembro BBK weight penalty removed. · T4 Ford Mustang V6 05-10 allowed aluminum driveshaft, any LSD, and Ford brake kit M-2300-D. · Pontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18 x 9.5 inches, Sky weight drops to 3200 lbs. · Mazda RX-8 Base/R3/Sport/GT (04-12) classified in T3 effective 2020-02-01. · T4 Mazda3 14-18 gains permitted modifications: springs to 800/1000 lbs, 15 lb wheels, cold air intake, camber plates, 25mm rear bar, mirrors, CorkSport arms, header, specific calipers and rotor. · T4 allows aftermarket OEM coolant expansion tanks with no other functional purpose. · T4 Mazda MX-5 Club Model 06-15 now allows aftermarket power steering reservoir. · T4 Subaru BRZ and Scion FR-S allowed factory installed wings. · T4 now permitted to use any OEM diameter clutch disc and pressure plate, previously T2-T3 only. · Chevrolet Sonic 2011+ added to T4 at 2800 lbs with 1364 cc engine and 225 max tire size. · T4 Mazda MX-5/Miata 1999-2005 minimum weight reduced 50 lbs to 2400. · T2 requires onboard fire system; T3 and T4 may have one per GCR 9.3. · T3 Ford Mustang EcoBoost 2015- gains three transmission gear ratio options. · T2 Chevrolet Camaro SS/1LE (10-14) adds Dailey Engineering dry sump P/N 20-02-0666-ASSY and other approved parts. · T2 Camaro SS 1LE gains approval for half shafts Drive Shaft Shop RA-5424 and RA-5425. · T2 Ford Mustang Boss 302 restrictor 54mm to 56mm; GT 5.0L 11-14 restrictor 52mm to 54mm; GT 5.0L 15-17 restrictor 50mm to 52mm; C5 Z06 weight 3525 to 3475 lbs; C6 weight 3450 to 3400 lbs; Porsche 911 997.2 restrictor 60mm to 57mm. · T2 Chevrolet Camaro 1LE 2016- weight reduced from 3600 to 3550 lbs. · T2 Honda Civic Type-R (2017-) weight reduced from 3050 to 3000 lbs; tire TIR requirement increased from 50mm to 51mm. · Mazda RX-8 Base/R3 (04-12) reclassified in T3 and T4 to include Sport and GT variants. · Toyota 86 GT (2017-) added to T3 and T4 Spec Line. · T2 requires onboard fire system; T3 and T4 may have one per GCR 9.3. · T3 Ford Mustang EcoBoost 2015- gains three transmission gear ratio options. · T4 BRZ, FR-S, and 86 maximum tire size reduced from 245 to 225. · T4 Mazda MX-5 Club Model 06-15 minimum weight cut from 2625 to 2550 lbs. · Mazda RX-8 Base/R3 (04-12) reclassified in T3 and T4 to include Sport and GT variants. · Toyota 86 GT (2017-) added to T3 and T4 Spec Line. · AS Spec Mustang (SMG) added as Restricted Prep class. · T2-T4 spare tire/wheel rules clarified: removable covers can be removed with hardware and bracketry. · T2-T4 spare tire/wheel rules clarified: removable covers can be removed with hardware and bracketry. · T4 Mazda MX-5 Club (06-15) gains suspension package with 100 lbs weight increase, allows RX8 hubs and SM5 suspension, permits non-OEM LSD with 50 lbs penalty. · AS class minimum ride height clarified to 5 inches measured at rocker panel, excluding seams and cladding. · T2 Cadillac CTS-V classification expanded from 06-07 to include 04-05 model years. · T2 Cadillac CTS-V 06-07 allowed to use Hotchkiss sway bars up to 36mm front, 25mm rear. · T2 Cadillac CTS-V 06-07 requires 57mm flat plate restrictor. · T2 Ford Mustang GT 5.0L tire size reduced from 315 to 295. · T4 Toyota MR-2 Spyder 16V DOHC years corrected from 01-05 to 00-07. · AS Ford Mustang (79-93) 313 CID and under loses 100 lbs to 3150; over 313 CID loses 100 lbs to 3450. · T2 2018+ Audi TT RS gains suspension and intercooler allowances: 30mm front sway bar, 28mm rear, 1200lb/in springs, aftermarket intercooler. · T2 Honda Civic Type-R 2017- weight rises 2900 to 3050 lbs, TIR increases 38mm to 50mm. · T4 Mazda Protégé ES 2000 now allows piggyback ECU tuning device; OBD2 requirement waived. · T4 Mazda MX5 Club Model 06-15 allows suspension package with 100 lbs weight increase including helper springs. · T2 Mustang GT anti-roll bars may now be removed or disconnected, previously required as manufactured. · T4 BMW 323 (98-00) newly classified at 3450 lbs with 50mm flat plate restrictor and M52TUB25 engine required. · T1-LP Ford Mustang GT 5.0L 2018+ classified at 3400 lbs with 65mm flat plate restrictor. · T2 Audi TT RS (2018-) newly classified at 3400 lbs minimum weight with 19-inch wheels and 275 tire size. · T2 2017 Civic Type R allows any sway bar front/rear up to 30mm, front springs to 800lb, rear to 2000lb. · T4 Mazda MX-5 Club (06-15) and (2016-), T3 MX-5 Cup and Miata (2016-) hardtop rules clarified; wording changes to permitted parts and specifications. · T2, T3, T4 now allow any thermostat serving only OE intent, previously restricted. · T2 Ford Mustang Boss 302 (12-13) weight drops 50 lbs to 3500. · T2 Corvette C6 Coupe/Grand Sport removes 3.0 degrees MAX front camber restriction. · T2 Pontiac Firebird and Chevrolet Camaro SS (98-02) permitted spring relocation to shock. · T3 and T4 Mazda MX-5 Miata eligibility capped at 2018 model year, effective 2019-03-01. · Ford Mustang GT 5.0L 2018+ classified in T2 at 3600 lbs with 50mm restrictor, 19x11 wheels, 315 tyres. · T4 Mazda MX-5 Club (06-15) and (2016-), T3 MX-5 Cup and Miata (2016-) hardtop rules clarified; wording changes to permitted parts and specifications. · T2, T3, T4 now allow any thermostat serving only OE intent, previously restricted. · T3 and T4 Mazda MX-5 Miata eligibility capped at 2018 model year, effective 2019-03-01. · AS Spec Mustang (SMG) newly classified with 107.1 wheelbase, 3.73 gears, 355mm front brakes, 300mm rear. · T4 Honda Civic Si 2012-2015 permitted sway bars increased to 32mm front and rear. · T4 Ford Fiesta ST years corrected to 14-; T4 Fiat 124/Abarth Edition years added 16-18; battery rule clarified. · T2 Porsche Cayman S/GTS model years expanded from 13-14 to 13-15, now includes GTS variant. · T2 Honda Civic Type-R 2017- allows Cuztom Tuning FG-CIV16-V3-TR-BK alternate grill. · T1-T3 spec cars receive clarifications on permitted modifications, documentation requirements, and rule conformance; no performance changes. · T2-T4 subframe bushings may now be replaced with non-spherical bushings of any material. · T4 Ford Fiesta ST years corrected to 14-; T4 Fiat 124/Abarth Edition years added 16-18; battery rule clarified. · T4 Fiat 124 Abarth Edition restrictor changes from 29mm flat plate to 30mm TIR. · T1-T3 spec cars receive clarifications on permitted modifications, documentation requirements, and rule conformance; no performance changes. · T2-T4 subframe bushings may now be replaced with non-spherical bushings of any material. · Scion FR-S and Subaru BRZ 13-16 Solo Spec Coupes added to T4, both 1998cc, 2570 lbs, 225/45/17 tires.showhide
T4 Mustang OEM Grill Request #33333aeroaeroT2/T3 Mustang GT 5.0L and V6 (11-14) may remove upper grille fog lights, replace with mesh or screen.
T4 Mazda OEM LSD was letter 32655 typo #33666wordingwordingT4 Mazda MX-5 Club Model 06-15 Mazda Motorsports LSD part number corrected from 32655 to 0000-02-5564.
T2 BMW M235iR/M240iR Aftermarket 2WNR Shocks Allowed - Touring 2 #33464weight -50 lbsfasterT2 BMW M235iR weight reduced 50 lbs to 3350, aftermarket shocks now allowed.
T2 Touring (T2-T5) Category #33617cars addedcars addedT5 class added as regional-only; T5 tyres maximum width 225, minimum aspect ratio 45.
T2 ENO 9.1.9.2.D.1.e.1.a. #33651suspension & brakessuspension & brakesT2-T5 Touring front and rear suspension maximum negative camber changed to 3.5 degrees.
T4 Allowable Springs and Sway Bars for 06-11 Civic si Spec Line #33294suspension & brakesfasterT4 Honda Civic Si 06-11 now permits 32mm sway bars front and rear and 700 pound springs.
T4 Touring (T2-T5) Category #33617cars addedcars addedT5 class added as regional-only; T5 tyres maximum width 225, minimum aspect ratio 45.
T4 ENO 9.1.9.2.D.1.e.1.a. #33651suspension & brakessuspension & brakesT2-T5 Touring front and rear suspension maximum negative camber changed to 3.5 degrees.
T2 Heavy Cars #33345weight +125 lbsslowerT2 Dodge Viper SRT-10 wheel size 18x11 rear, weight to 3675 lbs, throttle restrictor hole 44mm convertible or 42mm hardtop.
T4 T4 mustang #32789tyres & wheels -25 lbsfasterT4 Ford Mustang V6 (05-10) wheels widen to 18x9, front brakes grow to 314mm vented, weight drops to 3275 lbs.
T4 Mazda OEM LSD was letter 32655 #32933weight -25 lbsfasterT4 Mazda MX-5 Club (06-15) minimum weight drops 25 lbs to 2600; Mazda LSD #32655 now permitted without penalty.
T4 Another 2022 BRZ/86 T3 request #32945weight +225 lbsslowerT3 Subaru BRZ 2022- minimum weight up to 2975 lbs; spring rate to 1000 F/R, brake parts allowed without penalty.
AS Request to add Hoosier W2 #33031tyres & wheelstyres & wheelsAS allows Hoosier W2 tyre option in addition to R7, R6, WET/H20.
AS correction of Dodge Challenger specification line #33151wordingwordingAS Dodge Challenger 08-20 adds two transmission ratio options: 2.97, 2.10, 1.45, 1.00, 0.74, 0.50 or 2.26, 1.58, 1.19, 1.00, 0.77, 0.63.
AS Request CTS-V Spec Line Error Correction #30242weightfasterAS Cadillac CTS-V 6.0L V8 removes 50 lbs weight penalty for 295 tire size.
T2 BMW M235iR/M240iR Min Weight Clarification #32430wordingfasterT2 BMW M235iR/M240iR: 240iR/Evo package now permitted without 50 lb penalty; Evo package clarified to 75 lbs.
T2 Follow up to Letter 30888 #32477suspension & brakesfasterT2 BMW E92 M3 (08-14) permitted to use Fall Line Suspension arms from G8X/F8x/E9x M3, E9x M3/E82 1M.
T4 Request Wider Wheels for Hyundai Tiburon #32536tyres & wheelsfasterT4 Hyundai Tiburon V-6 wheel width increases from 7 to 8 inches at 17-inch diameter.
T2 Request Alternate Front & Rear Strut/Shock Top Hats #32452suspension & brakessuspension & brakesT2-T4 Touring cars with alternative springs may use performance top hats with spherical bearings on shocks and struts.
T2 Request BoP E92 torque #32456wordingwordingT2 BMW E92 M3 (08-14) note reference changed from 77 to 78.
T2 Classify Cadillac Blackwing #32535cars addedcars addedCadillac CT4-V Blackwing (2022+) classified in T2 at 3800 lbs with 94 x 85.6mm engine.
T4 Request to Add Spec Line for 2004-2009 Mazda3 i 2.0 #32395cars addedcars addedT4 Mazda3 i 2.0L added as spec line with 1999cc displacement and 2425 lbs minimum weight.
T4 Request Alternate Front & Rear Strut/Shock Top Hats #32452suspension & brakessuspension & brakesT2-T4 Touring cars with alternative springs may use performance top hats with spherical bearings on shocks and struts.
T2 Request to Allow the Use of Aftermarket ECU's in Touring #31067weightslowerT2-T4 cars model year 2018+ may use non-OEM ECU with 75 lb weight penalty via spec line adjustment.
T2 BMW M2 CS Cup 2020- Exhaust #32243wordingunclearBMW M2 CS Cup 2020- now permits specific exhaust part #18302459928 and hot country package cooling parts.
T4 Request to Allow the Use of Aftermarket ECU's in Touring #31067weightslowerT2-T4 cars model year 2018+ may use non-OEM ECU with 75 lb weight penalty via spec line adjustment.
T4 Request JWT BSR Kit for 02-06 Nissan Sentra SE-R/Spec V #31685enginefasterT4 Nissan Sentra SE-R Spec V 02-06 now permits balance shaft removal kit OQR25-NOBAL.
T4 Please Confirm Touring 4 (98-00) BMW 323 is E46 generation #31972wordingunclearT4 BMW 323 (98-00) wheelbase increases to 2725 mm, final drive ratio changes to 3.07.
T4 RX-8 Spring Part Numbers (E&O) #32151suspension & brakessuspension & brakesT4 Mazda RX-8 04-12 gains Eibach spring alternatives to Mazda Motorsports springs front and rear.
T4 04-09 Mazda3 Tire Limit Clarification #32249tyres & wheelsfasterT4 Mazda3 04-09 tire size increases from 235 to 245.
T4 Shock Part Number Errors & Omissions #32252wordingwordingT4 Ford Mustang V6 05-10 shock part numbers corrected to 8741-1494SPORT front and 8241-1240SPORT rear.
T4 Update Solo Spec Coupe to latest '20 specs for Road Racing #32262wordingunclearT4 Scion FR-S and Subaru BRZ Solo Spec Coupes updated to 2020 specifications Rev 7/20.
T4 Request 2016 Mazda MX5 springs #32265suspension & brakesslowerT4 2016–18 Mazda MX-5 Miata/Club gains 100 lbs. for approved suspension package with specific springs.
T2 Reply to letter #31486/29879 T2-T4 Grill openings #31935aerofasterT2-T4 grill openings may remove non-metallic webbed false sections; 16 square inch limit removed.
T2 C6 Restrictor Help #31995inductionfasterT2 Chevrolet Corvette C6 LS2 restrictor increases from 56mm to 58mm.
T4 Reply to letter #31486/29879 T2-T4 Grill openings #31935aerofasterT2-T4 grill openings may remove non-metallic webbed false sections; 16 square inch limit removed.
T4 BRZ vs BRZ TS #32022wordingwordingT3 Spec Lines Subaru BRZ TS (13-21) added to class specification wording.
T2 BMW Z4M Adjustment #31885weight -50 lbsfasterT2 BMW Z4M 06-08 weight reduced from 3150 to 3100 lbs.
T4 MX-5 Durability Detailed #31102weightslowerT4 Mazda MX-5 Club 06-15 allows non-OEM LSD with +50 lbs penalty; removes stock transmission and differential requirements.
T4 Request Allowances for 2005 - 2010 Mustang #31624suspension & brakessuspension & brakesT4 2005-2010 Ford Mustang V6 now specifies Koni damper part numbers 8741.1494 front and 8741.1240 rear.
AS Proposed Revisions to SCCA GCR 2021 Appendix M, Part 3 #30295wordingwordingSMG long tube headers: Borla PN 17237 discontinued, Kooks PN 11312000 and American Racing PN MT3-05134300LSNC approved alternatives.
AS specification line consolidation and correction #31846wordingwordingAS Mercury Capri (79-86) removed as individual spec line, merged into Ford Mustang (79-93) spec line.
AS correction of SMG specification line #31847wordingunclearAS Spec Mustang SMG loses 3.73 gear ratio and 355/300 mm brake specification.
AS Alternate cylinder heads for full prep engine builds - Evaluation #31851engineunclearAS Chevrolet, Pontiac, Ford full prep engines now permit alternate cylinder heads with restrictor plate ALL26180 and 1.250 inserts ALL26186 for regional competition.
T2 Touring 2 BOP adjustments for 2022 #31480weight -50 lbsfasterT2 Dodge Viper SRT-10 loses 50 lbs to 3550; throttle restrictor hole shrinks from 43mm to 41mm.
T2 Reply to letter 29879 T2-T4 Grill Openings #31486aerofasterT2-T4 clarified: grill opening area may increase max 16 sq in for radiator cooling only, retaining factory mesh shape.
T2 Request to clarify radiator hoses #31682wordingwordingT2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted.
T2 Clarify Permitted/Allowed #31743wordingwordingT2, T3, T4 clarify that spec lines listing permitted or allowed parts are alternatives to category rules, not replacements.
T2 SMG #31837wordingwordingT2 Spec Mustang model designation changed to Ford Spec Mustang.
T4 Reply to letter 29879 T2-T4 Grill Openings #31486aerofasterT2-T4 clarified: grill opening area may increase max 16 sq in for radiator cooling only, retaining factory mesh shape.
T4 Please Adjust 98-00 BMW 323 Min Weight to Reflect Current Class #31595weight -200 lbsfasterT4 BMW 323 98-00 minimum weight drops to 3250 lbs, 50mm restrictor removed.
T4 Consolidate 12-13 and 14-15 Honda Civic Si spec lines for T4 #31596wordingwordingT4 Honda Civic Si consolidates 12-13 and 14-15 into single 12-15 spec line with updated suspension allowances.
T4 Request to clarify radiator hoses #31682wordingwordingT2, T3, T4 radiator and coolant hoses may be replaced with aftermarket options; coolant temp sensor modification permitted.
T4 Clarify Permitted/Allowed #31743wordingwordingT2, T3, T4 clarify that spec lines listing permitted or allowed parts are alternatives to category rules, not replacements.
T4 Correct RSX wording #31746wordingfasterT4 Acura RSX/RSX Type-S 02-06 removes requirement that original wheels must remain stock.
T4 Camaro #31751suspension & brakesfasterT4 Chevrolet Camaro V-6 (96-02) removes requirement that shock/struts, mounts, and transmission differential remain stock.
T2 Typo for BMW M2 CS Cup 2020 #31173suspension & brakesslowerT2 BMW M2 CS Cup 2020 rear brake rotor reduced from 390 mm to 380 mm.
T4 Nissan Sentra SE-R Spec. V #30958cars addedcars addedNissan Sentra SE-R Spec V (2007–2012) newly classified in T4 at 3000 lbs minimum weight.
T4 Mazda RX-8 Spec Line Suspension Parts #31113suspension & brakesfasterT4 Mazda RX-8 04-12 allows alternate sway bars max 32mm front, 19mm rear; removes 60mm restrictor requirement.
T4 Diverter Valve Plunger Upgrade #31307wordingwordingT4 BMW 320i (14-15) now allows GFB T9357 aluminum diverter valve.
T4 Adjust Honda FWD in T4 to encourage more Drivetrain Diversity #31472tyres & wheelsfasterT4 Honda Civic FWD gets wider 8-inch wheels, 245 tyres max, and sway bar allowances to 29mm front, 22mm rear.
T4 Touring 4 BOP adjustments for 2022 #31482weight -175 lbsslowerT4 multiple cars: Volkswagen Rabbit 2.5 (08-09) to 2675 lbs; Mazda MX-5/Club (06-15) to 2625 lbs; RX-8 to 3125 lbs; Honda/Acura/Chevy/Mazda wheel widths 7 to 8 inches.
T2 Request to Classify 2014 VW Jetta 1.8t TSI #30436cars addedcars addedT4 Volkswagen Passat, Jetta 1.8T adds 2014 model year to eligible years.
T2 Request new car 2017 BMW M2 #30486cars addedcars addedBMW M2 (2017+) added to T2 with 2979cc engine, 10.5x18 wheels, 295 tires, 3650 lbs weight.
T2 Request to Classify Porsche 997.2 GTS in T2 (body not = to C2S) #30686cars addedcars addedPorsche 911 997.2 GTS (09-12) classified in T2 at 3400 lbs with 60mm flat plate restrictor required.
T4 Request to Classify 2014 VW Jetta 1.8t TSI #30436cars addedcars addedT4 Volkswagen Passat, Jetta 1.8T adds 2014 model year to eligible years.
AS Request for adjustable Front Upper Control Arms on 4th Gen F-Body #30457suspension & brakessuspension & brakesAS Chevrolet/Pontiac Camaro & Firebird 93-02 now allow BMR AA004 or UMI 2310 adjustable front upper control arms.
AS Request Pontiac GTO tire size change #30881weightslowerAS Pontiac GTO 04-06 LS1 to 3300 lbs, LS2 to 3350 lbs on 295 tire.
T2 BMW M2 CS Power Stick Part Number #31087wordingwordingT2 BMW M2 CS Cup 2020- must run Purple power stick, part #8324089 instead of #TBD.
T2 997.1 EO #30933wordingwordingT2 Porsche 911/997.1 (06-08) now allows alternate Cargraphics CARP97DFIFKR exhaust manifold.
T2 Request #30406weightfasterT2 BMW M2 CS Cup 2020- weight increases from 3625 to 3600 lbs; mandatory Purple power stick added.
T4 Wrong Part Number on 320i Spec Line #30645wordingwordingT4 BMW 320i 14-15 part number corrected from 20121.140 to E10-20-031-01-22.
AS Request CTS-V Spec Line Error Correction #30242weightfasterAS Cadillac CTS-V 6.0L V8 removes 50 lbs tire size penalty, making it lighter.
AS Request to consolidate SN95 Mustang '94-'04 Mustang spec lines #30428wordingwordingAS consolidates seven SN95 Mustang spec lines into three: 94-04 including Cobra, 94-95 5.0/5.8, and 96-04 4.6L two/four valve.
AS American Sedan Transmission Rule Change Request #30595enginefasterAS Camaro/Firebird LT1/LS1 transmission code changes to 6362; Mustang GT 4.6L/5spd changes to 5.0L/6spd with 300 lbs weight reduction.
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 lbsslowerAS Chevrolet Camaro & Firebird, Ford Mustang variants, Mercury Capri minimum weights increase 50 lbs across all model years.
T2 Civic Type R Brake Rotors #29817weightslowerT3 Honda Civic Type-R 2020+ allows brake rotor 45251-TGH-A01 with 25 lb penalty.
T2 Mustang S550 Parity in T2 #29925inductionfasterT2 Ford Mustang GT 5.0L 15-17 restrictor grows 55mm to 58mm; 2018- grows 53mm to 55mm.
T2 Request BOP on BMW Z4 T2 car #30597weight +50 lbsslowerT2 BMW Z4M 06-08 weight increases from 3100 to 3150 lbs.
T2 E92 #30639weight -50 lbsfasterT2 BMW E92M3 08-14 weight drops 50 lbs to 3425, intake restrictor reduces 3mm to 77mm.
T4 Civic Type R Brake Rotors #29817weightslowerT3 Honda Civic Type-R 2020+ allows brake rotor 45251-TGH-A01 with 25 lb penalty.
T2 C5/6 Corvette in T1, T1-LP and T2 Dry Sump Standardization #29046wordingwordingT2 C5 and C6 Corvettes permit specific dry sump kits and minor air dam trimming up to 3.9 cm depth.
T2 Request for Chevrolet Camaro 1LE (2016-) Auto Trans #29067wordingunclearT2 Chevrolet Camaro 1LE auto trans gets new gear ratios and 2.77 final drive ratio.
T2 Request to add 2015 to Chevrolet Camaro SS/1LE 2010-2014 #29736cars addedcars addedT2 Chevrolet Camaro SS/1LE model years expanded from 2010–2014 to 2010–2015.
T4 Mini Cooper Spec Line Anomalies #30478suspension & brakesunclearT4 Mini Cooper S (02-04, 05-06) suspension/wheel rules simplified; (07-13) gear ratios changed to 3.31, 2.13, 1.48, 1.14, 0.95, 0.82, final drive to 3.65, brakes to 280 mm.
T4 Request CAI Mustang in T4 #30562inductionfasterT4 Ford Mustang V6 05-10 now allows cold air intake.
T2 Request consistency review in GCR #30263wordingslowerT2-T4 clutch disc and pressure plate must be at least 95% of factory OEM weight.
T2 Class Spec Corvette in T2? #30297cars addedcars addedSpec Corvette newly classified in T2 at 3375 lbs with 53mm restrictor and 3.75" minimum ride height required.
T2 E92 BMW Spring Rate Request #30391suspension & brakesfasterT2 BMW E92 M3 front and rear springs increased to 1000 lbs/in from 800.
T2 Please correct recent T2 Spec Line #30401suspension & brakessuspension & brakesT2 Toyota Supra 2020- spring rates limited to 800# front and 1000# rear maximum.
T4 Request consistency review in GCR #30263wordingslowerT2-T4 clutch disc and pressure plate must be at least 95% of factory OEM weight.
AS AS Mustang LP 4.6 3V Classification Transmission Request #29886weightfasterAS Mustang 4.6L/5spd loses 300 lbs; 5.0L/6spd gains 56mm restrictor requirement.
AS Request CF driveshaft on CTS-V for durability improvement #30117otherotherAS CTS-V LS6 and LS2 may now use Driveshaft Shop carbon fiber driveshaft for durability.
AS Adjustment to model years of 5th generation RP Camaro #30348wordingwordingAS Chevrolet Camaro SS V8 6.2L model years extended from 10-13 to 10-15.
T2 Request BMW M2CS door glass removal #30254aerofasterT2 BMW M2 CS Cup 2020- permitted to remove door glass and mechanism.
T4 E & O T4 Mustang Wheels #30245tyres & wheelsfasterT4 Ford Mustang V6 05-10 wheels increase from 17 to 18 inches.
T2 Request Addition of BMW M240iR #29503cars addedslowerT2 BMW M235iR allows 240iR/Evo package with 50 lb penalty, must run DOT tires.
T2 2021 Toyota Supra #29567cars addedcars addedToyota Supra 2020- newly classified in T2 at 3450 lbs minimum weight with 295 tire and 19-inch wheels.
T2 Request Cold Air Intake for Honda Civic Type R #29942wordingwordingT2 Honda Civic Type-R gains allowance for PRL cold air intake #PRL PRL-HCR-INT-HVI.
T2 Adjust T2 spec line that was missed in T2 BOP #30055weight -50 lbsfasterT2 Porsche Carrera S 997.2 (06-08) weight reduced 50 lbs to 3225.
T2 Fix T2 Mustang spec line #30106wordingwordingT2 Ford Mustang GT 5.0L (15-17) gear ratios corrected to 3.66, 2.43, 1.69, 1.32, 1.00, 0.65 or 4.17, 2.34, 1.52, 1.14, 0.87, 0.69.
T2 Z4 Wheel Size #30113tyres & wheelsfasterT2 BMW Z4M 06-08 maximum wheel size increases from 18x9 to 18x10 inches.
T2 Clarify T2 Spec lines #30194wordingwordingT2 BMW M2 CS Cup 2020- and M235iR clarify homologation notes for DOT tires and BMW Motorsports components.
T4 2021 Toyota Supra #29567cars addedcars addedToyota Supra 2020- newly classified in T2 at 3450 lbs minimum weight with 295 tire and 19-inch wheels.
T4 06-15 MX-5 Durability #29781wordingwordingT4 Mazda MX-5 durability rule now applies to T2-T4 instead of T2-T3 only.
T4 Request for Update to T4 Spec Line for Chevrolet Sonic (2011-) #29838wordingwordingT4 Chevrolet Sonic (2011-) spec clarified: 28mm TIR restrictor placement, PCV plug requirement, and allowed suspension parts listed.
T4 NC MX-5 06-15 Part Number updates for 2021 #29921wordingwordingT4 Mazda MX-5 06-15 removes front and rear end links from suspension package spec.
T4 BMW Z4 2.5L (03-05) Spec Line #30037weight -50 lbsfasterT4 BMW Z4 2.5L (03-05) minimum weight reduced from 3100 to 3050 lbs.
T4 Sway Bars for T4 2016+ MX5 Mazda #30063suspension & brakessuspension & brakesT4 2016+ Mazda MX-5 Miata gains allowance for 29mm front and 16mm rear sway bars.
T4 Change part numbers on BRZ, FRS lines in T4 #30104wordingwordingT4 Scion FR-S, Subaru BRZ, and Toyota 86 replace Eibach part 4.10582.880 with 82105.320, 4.10582 and SPC 67660.
T4 T4 Mustang Axle Ratio and Wheels #30149weightslowerT4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.45 or 3.55 ratio at +25 lb penalty.
AS Request for 2015 -2017 Ford Mustang Spec Line #29514cars addedcars addedFord Mustang GT 5.0L 15-17 Restricted Preparation classified in AS with 55mm flat plate restrictor required.
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 #29759weightfasterAS Cadillac CTS-V 04-07 with 295 tire drops to 3450 lbs; Camaro SS V8 10-13 275 tire removed; Challenger 08-20 gains 315 tire option at 3600 lbs.
AS Correction to specifications inadvertently deleted #30041weightfasterAS Camaro & Firebird (93-02) and Mustang GT (05-14) specifications restored with 200 lb weight reduction for permitted heads.
T2 Request to Classify BMW M2 CS #29523cars addedcars addedBMW M2 CS Cup 2020+ classified in T2 at 3625 lbs with 2979cc engine, 10.5x18 wheels, 295 tires.
T2 350Z Rear Caliper Replacement #29710wordingwordingT2 and T3 Nissan 350Z and 370Z permit 44011-RC350 rear caliper kit and SZ350 rotors.
T2 Request Mustang 8.8†rear axle replacement #29860weightslowerT4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.55 final drive, adds 25 lb penalty.
T2 Cap year range on all 86s #29908wordingwordingT3 and T4 FR-S, 86, and BRZ year ranges capped: T3 at 2021, T4 at 2017-2021.
T4 Request to Classify BMW M2 CS #29523cars addedcars addedBMW M2 CS Cup 2020+ classified in T2 at 3625 lbs with 2979cc engine, 10.5x18 wheels, 295 tires.
T4 Allow the SpecMX-5 Update Kit Into Touring 4 for the MX-5 #29681wordingunclearT3 and T4 Mazda MX-5 06-15 now allow Mazda Transmission kit part # 0000-02-5700.
T4 Request Mustang 8.8†rear axle replacement #29860weightslowerT4 Ford Mustang V6 05-10 allows GT 8.8 rear axle with 3.55 final drive, adds 25 lb penalty.
T4 Cap year range on all 86s #29908wordingwordingT3 and T4 FR-S, 86, and BRZ year ranges capped: T3 at 2021, T4 at 2017-2021.
AS Request Additional Engine Options for Dodge Challenger Spec Line #29543engineslowerAS Dodge Challenger 08-20 gains 6.1L and 6.4L V8 options; 5.7L weight rises to 3500 lbs on 295 tyres, 3600 on 315 tyres.
AS Rule simplification spec line communization #29824wordingfasterAS Camaro/Firebird (93-02) and Mustang Coupe GT (05-14) consolidated into single specs with 100 lb and 300 lb weight reductions respectively.
T2 Request to Reevaluate T2 Spec Line for E92 M3 #28266weight -50 lbsfasterT2 BMW E92 M3 (08-14) weight reduced 50 lbs to 3475, with detailed brake, spring, sway bar, and restrictor specs.
T2 Request for Parity Among Vehicles Including S550 Mustang #29486induction -75 lbsfasterT2 Corvette C5 Z06 restrictor sizes increase to 53mm and 58mm; C6 LS2 to 56mm, LS3 to 50mm; Camaro SS/1LE weight drops 75 lbs to 3625; 2016+ Camaro restrictor to 56mm; Mustang GT 11-14 to 58mm, 15-17 to 55mm, 2018+ to 53mm; Viper SRT-10 th…
T2 Alfa Romeo 4C Launch Edition #29531wordingwordingT3 Alfa Romeo 4C Launch Edition now allowed in Spec Lines.
T4 Alfa Romeo 4C Launch Edition #29531wordingwordingT3 Alfa Romeo 4C Launch Edition now allowed in Spec Lines.
T4 Post Runoffs Feedback for T4 #29752tyres & wheels -50 lbs
T2 Request 2018+ mustang swaybar update #28659wordingwordingT2 Ford Mustang GT 5.0L and Ecoboost 2.3 sway bar part numbers added to notes.
T2 Request to Clarify New 2-piece Brake Rotor Rule #29106wordingwordingT2 brake rotors expand from ferrous metal only to 2-piece ferrous disks with aluminum hats, within 5% OE diameter.
T2 please consider BoP for the following cars in T2 #29266weight -50 lbsfasterT2 Corvette C-5 Z06 loses 50 lbs to 3425; Camaro SS/1LE loses 50 lbs to 3650; Mustang GT and Boss 302 gain 275 to 295 tyres.
T2 Request clarification on most recent approval by the Board #29284wordingwordingT2 Porsche Cayman S, Spyder (10-12) allows 800#/in front and 1000#/in rear springs, cooler ducting, rotor ducting, and specific Porsche and StopTech brake items.
AS Dodge Challenger AS Spec Line Clarification #28698engineslowerAS Dodge Challenger 5.7L V8 gets iron block requirement, 10.5:1 compression max, intake valve 12.7 mm, exhaust 12.3 mm, intake duration 188°, exhaust duration 205°.
AS Dodge Challenger AS Spec Line Clarification #2 #28699wordingwordingAS Dodge Challenger 08-14 rear spoiler part number changes from 1GL20RXF to 1GL20TZZAB.
T2 Request to correct GCR for 2018+ FORD Mustang GT & Ecoboost #28803wordingwordingT2 Ford Mustang EcoBoost and GT 5.0L gain three optional gear ratio sets for competition use.
T4 Scion FRS Solo Spec Coupe Gear Ratio #29021otherfasterT4 Scion FRS and Subaru BRZ Solo Spec Coupe final drive ratio changed from 4.30 to 4.10.
AS Support for R-Type Specification Tires #27450tyres & wheelsunclearAS class pursues specified list of eligible tires; details of tire changes not provided in letter.
AS Spec Tire Request #27519tyres & wheelsunclearAS class pursuing specified list of eligible tires; details pending further communication.
AS Restrictor Plate Change for RP 2011+ Mustang with Coyote Engine #27675wordingunclearNo restrictor plate change implemented; 2021 AS Mustang Coyote under evaluation.
AS 2005-2009 Restricted Prep 4.6 3V #27908engineunclearAS 2005-2009 Restricted Prep 4.6 3V now permits conversion to 2 valve configuration.
AS Request for 2005-2009 Restricted Prep 4.6 3V Parts #27909wordingunclearAS 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 #28030cars addedunclear2010-2014 Camaro reclassified to AS; full preparation classification approved effective 2020-07-01.
AS Cylinder Heads #28696wordingunclearAS class cylinder head replacement options under review; implementation planned for 2021 season.
AS Request for Max Rotor Diameter Change #28748suspension & brakesfasterAS Mustang, Camaro, Firebird, Capri max brake rotor diameter increases from 12.2 to 13.1 inches.
AS Request increase rotor diameter #28797suspension & brakessuspension & brakesAS rotor diameter increase approved; see Fastrack letter #28748 for details.
T2 Request to Add a Vehicle to the Roster (contd.) #27698cars addedunclearCannot read: letter references external document #27663 not provided.
T2 Request brake upgrade and electric power steering pump #28946suspension & brakesfasterT2 Porsche Cayman S, Spyder (10-12) gains brake, suspension, and drivetrain upgrades: StopTech calipers, 800#/in front and 1000#/in rear springs, Porsche control arms, PDK allowed.
T4 T4 RX8 bodywork clarification #28941aeroaeroT4 Mazda RX-8 04-12 now allows OE rear spoiler #F151-V4-920F and OE front air dam #F151-V4-900f-BB.
T4 2006-2015 MX-5 Clarification #28942otherfasterT4 2006-2015 Mazda MX-5 Club Model now allows non-stock wheels; transmission, differential, LSD remain stock.
T4 Request to Add a Vehicle to the Roster (contd.) #27698cars addedunclearCannot read: letter references external document #27663 not provided.
T2 Request to Classify 2004 Mercedes Benz 320 CLK #27663cars addedcars added2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine and Eibach PN# 2563.140 springs allowed.
T2 Consider coil spring conversion Corvette in T2 #28824suspension & brakessuspension & brakesT1 and T2 Corvettes may convert leaf spring suspension to coilover with 800 lb max spring rate allowed.
T4 Request to Classify 2004 Mercedes Benz 320 CLK #27663cars addedcars added2004 Mercedes Benz CLK 320 Coupe classified in T4 at 3200 lbs with 3299cc engine and Eibach PN# 2563.140 springs allowed.
AS weight adjustments for 2020 season #28785weight -50 lbsfasterAS Chevrolet/Pontiac Camaro & Firebird (82-92) loses 50 lbs, to 3500.
T2 Please Add the Following BBK to Allowed List for E92 M3 #28421suspension & brakessuspension & brakesT2 BMW E92 M3 08-14 gains approved AP Racing brake kit part numbers 13.01.10038 front, 13.01.10053 rear.
T2 C5 Weight Adjustment #28433weight -50 lbsfasterT2 Chevrolet Corvette C5 Z06 loses 50 lbs with 45mm restrictor, to 3175; 50 lbs with 55mm restrictor, to 3350.
T2 Z3M Roadster Weight #28437weightfasterT3 BMW Z3 M & Coupe 1998-1999 weight reduced from 3350 to 3150 lbs.
T4 Request to change allowed header part # for T4 06-15 Miata #28223wordingwordingT4 06-15 Mazda MX-5 now allows header part numbers 0000-06-5407 or 0000-06-5407-NC.
T4 Z3M Roadster Weight #28437weightfasterT3 BMW Z3 M & Coupe 1998-1999 weight reduced from 3350 to 3150 lbs.
T2 Limit Changes to the 997.2 Porsche #28242aeroslowerT2 Porsche 911 997.2 allows GT3 Cup front fascia with 75 lb penalty; OEM rear deck lid and GT3 Cup splitter now required or prohibited.
T2 Correct T2 Mustang Transmission #28732wordingunclearT2 Ford Mustang GT 5.0L 15-17 transmission gear ratios corrected to two allowed options.
T2 Request to Readjust the T2 Porsches #27746aeroslowerT2 Porsche 911/997 (06-08, 09-12, Carrera S 06-08) aero rules relaxed; 997.2 adds 60mm restrictor and PDK +100lbs option.
T4 Request for 12-13 and 14-15 Honda Civic Springs #27848wordingwordingT4 Honda Civic Si 12-13 and 14-15 now allow H&R and HPD springs up to 700 pounds with 47mm restrictor.
T4 Request to Clarify T4 05-10 Mustang Spring Allowance #27899suspension & brakessuspension & brakesT4 Ford Mustang V6 05-10 springs now permitted max 500 lbs front and 400 lbs rear.
AS Rear Trailing Arms #28007suspension & brakessuspension & 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 #28010weightfasterAS Ford and GM full-prep cars get 200 lb weight reduction, up from 150 lb.
AS 05-10 Mustang with HR cam classification #28226cars addedcars added05-10 Ford Mustang Coupe GT 4.6L OHC classified AS with 3200 lbs minimum weight, HR cam restricted prep.
AS 10-15 Camaro Full Prep classification #28227cars addedcars addedAS 10-15 Chevrolet Camaro Full Prep classified with 3400 lbs base weight, over 313 CID engine 3700 lbs maximum.
T2 Please Switch the Solstice GXP as Specified in T2, to T3 #27413cars added -50 lbsfasterPontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18 x 9.5 inches, Sky weight drops to 3200 lbs.
T2 Request for Two Piece Stop Tech Brake Rotors #27582otherotherT2 cars now allowed to use ferrous metal 2-piece brake rotors within 5% of OE diameter.
T2 Request to Classify all Mazda RX8 Models in T3/T4 #27606cars addedcars addedMazda RX-8 Base/R3/Sport/GT (04-12) classified in T3 effective 2020-02-01.
T2 Request for Alternative Brake Kit on Nissan 370Z #27912suspension & brakesslowerT2 Nissan 370Z gains alternative Stoptech brake kit option with 50 lb weight penalty.
T2 2015- Current Ecoboost Mustang #27971weight -100 lbsfasterT2 Ford Mustang Ecoboost 2.3 loses 100 lbs to 3400, wheels widen to 19 x 11, intercooler TIR increases to 50mm.
T4 Request to Allow Brake Upgrade on T4 Mustang #27329otherotherT4 Ford Mustang V6 05-10 allowed aluminum driveshaft, any LSD, and Ford brake kit M-2300-D.
T4 Please Switch the Solstice GXP as Specified in T2, to T3 #27413cars added -50 lbsfasterPontiac Solstice GXP and Saturn Sky move from T2 to T3; wheels widen to 18 x 9.5 inches, Sky weight drops to 3200 lbs.
T4 Request to Classify all Mazda RX8 Models in T3/T4 #27606cars addedcars addedMazda RX-8 Base/R3/Sport/GT (04-12) classified in T3 effective 2020-02-01.
T4 Request for 2014-2018 Mazda 3 GT Brakes #27659suspension & brakesfasterT4 Mazda3 14-18 gains permitted modifications: springs to 800/1000 lbs, 15 lb wheels, cold air intake, camber plates, 25mm rear bar, mirrors, CorkSport arms, header, specific calipers and rotor.
T4 Request to allow aftermarket OEM coolant expansion tank #27763wordingwordingT4 allows aftermarket OEM coolant expansion tanks with no other functional purpose.
T4 Request to allow aftermarket OEM power steering reservoir #27764wordingwordingT4 Mazda MX-5 Club Model 06-15 now allows aftermarket power steering reservoir.
T4 Request for Factory Installed Wings on Subaru BRZ #27831wordingwordingT4 Subaru BRZ and Scion FR-S allowed factory installed wings.
T4 Request for Replacement Clutches #27892wordingwordingT4 now permitted to use any OEM diameter clutch disc and pressure plate, previously T2-T3 only.
T4 Request to Classify Chevy Sonic 1.4 In T4 #27906cars addedcars addedChevrolet Sonic 2011+ added to T4 at 2800 lbs with 1364 cc engine and 225 max tire size.
T2 Clarification of On-Board Fire System for T2 #27183wordingwordingT2 requires onboard fire system; T3 and T4 may have one per GCR 9.3.
T2 Mustang Ecoboost and GT Transmission #27439otherunclearT3 Ford Mustang EcoBoost 2015- gains three transmission gear ratio options.
T2 Request for Dailey Engineering Dry Sump on 2010 Camaro SS #27514otherotherT2 Chevrolet Camaro SS/1LE (10-14) adds Dailey Engineering dry sump P/N 20-02-0666-ASSY and other approved parts.
T2 Request for Half Shafts - 2014 Camaro SS 1LE #27584otherotherT2 Camaro SS 1LE gains approval for half shafts Drive Shaft Shop RA-5424 and RA-5425.
T2 Request for Parity Among Vehicles #27665induction -50 lbsfasterT2 Ford Mustang Boss 302 restrictor 54mm to 56mm; GT 5.0L 11-14 restrictor 52mm to 54mm; GT 5.0L 15-17 restrictor 50mm to 52mm; C5 Z06 weight 3525 to 3475 lbs; C6 weight 3450 to 3400 lbs; Porsche 911 997.2 restrictor 60mm to 57mm.
T2 Request for 2016-2020 Camaro SS Help #27776weight -50 lbsfasterT2 Chevrolet Camaro 1LE 2016- weight reduced from 3600 to 3550 lbs.
T2 Request for Competitive Adjustments to Honda Civic Type R #27839weight -50 lbsfasterT2 Honda Civic Type-R (2017-) weight reduced from 3050 to 3000 lbs; tire TIR requirement increased from 50mm to 51mm.
T2 T4 RX8 Classification Error #27902wordingwordingMazda RX-8 Base/R3 (04-12) reclassified in T3 and T4 to include Sport and GT variants.
T2 Request to add Toyota 86 GT to Spec Line #27910cars addedcars addedToyota 86 GT (2017-) added to T3 and T4 Spec Line.
T4 Clarification of On-Board Fire System for T2 #27183wordingwordingT2 requires onboard fire system; T3 and T4 may have one per GCR 9.3.
T4 Mustang Ecoboost and GT Transmission #27439otherunclearT3 Ford Mustang EcoBoost 2015- gains three transmission gear ratio options.
T4 BRZ/FRS/86 Tire Size in T4 #27660tyres & wheelsslowerT4 BRZ, FR-S, and 86 maximum tire size reduced from 245 to 225.
T4 NC MX5 2006-2015 Spec Adjustment Request #27739weight -75 lbsfasterT4 Mazda MX-5 Club Model 06-15 minimum weight cut from 2625 to 2550 lbs.
T4 T4 RX8 Classification Error #27902wordingwordingMazda RX-8 Base/R3 (04-12) reclassified in T3 and T4 to include Sport and GT variants.
T4 Request to add Toyota 86 GT to Spec Line #27910cars addedcars addedToyota 86 GT (2017-) added to T3 and T4 Spec Line.
AS Request to add SMG to 9.1.6.B.1 AS Intent #27140cars addedcars addedAS Spec Mustang (SMG) added as Restricted Prep class.
T2 Request spare tire/wheel clarification #27012wordingwordingT2-T4 spare tire/wheel rules clarified: removable covers can be removed with hardware and bracketry.
T4 Request spare tire/wheel clarification #27012wordingwordingT2-T4 spare tire/wheel rules clarified: removable covers can be removed with hardware and bracketry.
T4 Research E&O Mazda MX5 #27112suspension & brakesslowerT4 Mazda MX-5 Club (06-15) gains suspension package with 100 lbs weight increase, allows RX8 hubs and SM5 suspension, permits non-OEM LSD with 50 lbs penalty.
AS Request Ride Height Clarification #26598wordingwordingAS class minimum ride height clarified to 5 inches measured at rocker panel, excluding seams and cladding.
T2 Request to change Cadillac CTS-V years from 06-07 to 04-07 #26842cars addedcars addedT2 Cadillac CTS-V classification expanded from 06-07 to include 04-05 model years.
T2 Request to allow Hotchkiss front / rear sway bars on T2 CTS-V #26845suspension & brakesfasterT2 Cadillac CTS-V 06-07 allowed to use Hotchkiss sway bars up to 36mm front, 25mm rear.
T2 Correct T2 Mustang tire size #27024tyres & wheelsslowerT2 Ford Mustang GT 5.0L tire size reduced from 315 to 295.
T4 MR2 Spyder Year Correction #26936wordingwordingT4 Toyota MR-2 Spyder 16V DOHC years corrected from 01-05 to 00-07.
AS Request to Revert to 2017 Weights #25885weightfasterAS Ford Mustang (79-93) 313 CID and under loses 100 lbs to 3150; over 313 CID loses 100 lbs to 3450.
T2 2018+ Audi TT RS Suspension Allowances #26631suspension & brakesfasterT2 2018+ Audi TT RS gains suspension and intercooler allowances: 30mm front sway bar, 28mm rear, 1200lb/in springs, aftermarket intercooler.
T2 Request BOP adjustment for 2018 Honda Civic Type R-TIR removal #26882weight +150 lbsslowerT2 Honda Civic Type-R 2017- weight rises 2900 to 3050 lbs, TIR increases 38mm to 50mm.
T4 Request to allow piggy back ECU on 2000 Mazda Protégé #26085enginefasterT4 Mazda Protégé ES 2000 now allows piggyback ECU tuning device; OBD2 requirement waived.
T4 Request helper spring as optional #26678suspension & brakesslowerT4 Mazda MX5 Club Model 06-15 allows suspension package with 100 lbs weight increase including helper springs.
T2 Request for Removal of Rear Anti-roll Bar in T2 Mustang GT #26533suspension & brakesfasterT2 Mustang GT anti-roll bars may now be removed or disconnected, previously required as manufactured.
T4 Request to classify 2000 - 2001 BMW 323 #25096cars addedcars addedT4 BMW 323 (98-00) newly classified at 3450 lbs with 50mm flat plate restrictor and M52TUB25 engine required.
T2 Request Mustang GT Limited Prep 2018 Classification #24431cars addedcars addedT1-LP Ford Mustang GT 5.0L 2018+ classified at 3400 lbs with 65mm flat plate restrictor.
T2 Request to Classify 2018 Audi TT RS #25961cars addedcars addedT2 Audi TT RS (2018-) newly classified at 3400 lbs minimum weight with 19-inch wheels and 275 tire size.
T2 Request for Adjustments on 2017+ Civic Type R #25969suspension & brakessuspension & brakesT2 2017 Civic Type R allows any sway bar front/rear up to 30mm, front springs to 800lb, rear to 2000lb.
T2 Correct Mazda MX-5 Hard Top Notes #26137wordingwordingT4 Mazda MX-5 Club (06-15) and (2016-), T3 MX-5 Cup and Miata (2016-) hardtop rules clarified; wording changes to permitted parts and specifications.
T2 Consider opening class rules to allow any thermostat #26187wordingwordingT2, T3, T4 now allow any thermostat serving only OE intent, previously restricted.
T2 Ford Mustang Boss 302 (12-13) - correct weight #26287weight -50 lbsfasterT2 Ford Mustang Boss 302 (12-13) weight drops 50 lbs to 3500.
T2 Request camber correction 005-2013 corvette C6 #26288suspension & brakesfasterT2 Corvette C6 Coupe/Grand Sport removes 3.0 degrees MAX front camber restriction.
T2 Request 98-02 Firebird 98-02 Camaro reloacte rear spring #26291suspension & brakessuspension & brakesT2 Pontiac Firebird and Chevrolet Camaro SS (98-02) permitted spring relocation to shock.
T2 Cap 2016 Mazda Miata year at 2018 #26388wordingwordingT3 and T4 Mazda MX-5 Miata eligibility capped at 2018 model year, effective 2019-03-01.
T2 Class Ford Mustang GT 2018+ (reference letter 24431) #26400cars addedcars addedFord Mustang GT 5.0L 2018+ classified in T2 at 3600 lbs with 50mm restrictor, 19x11 wheels, 315 tyres.
T4 Correct Mazda MX-5 Hard Top Notes #26137wordingwordingT4 Mazda MX-5 Club (06-15) and (2016-), T3 MX-5 Cup and Miata (2016-) hardtop rules clarified; wording changes to permitted parts and specifications.
T4 Consider opening class rules to allow any thermostat #26187wordingwordingT2, T3, T4 now allow any thermostat serving only OE intent, previously restricted.
T4 Cap 2016 Mazda Miata year at 2018 #26388wordingwordingT3 and T4 Mazda MX-5 Miata eligibility capped at 2018 model year, effective 2019-03-01.
AS SMG Mustang eligibility in American sedan #26224cars addedcars addedAS Spec Mustang (SMG) newly classified with 107.1 wheelbase, 3.73 gears, 355mm front brakes, 300mm rear.
T4 2012-2015 Honda Civic Si Performance Request #26129suspension & brakesfasterT4 Honda Civic Si 2012-2015 permitted sway bars increased to 32mm front and rear.
T2 Errors, Omissions, and Updates (Various) #22414wordingwordingT4 Ford Fiesta ST years corrected to 14-; T4 Fiat 124/Abarth Edition years added 16-18; battery rule clarified.
T2 Request to classify 2015 Cayman GTS 3.4L in T2 #25335cars addedcars addedT2 Porsche Cayman S/GTS model years expanded from 13-14 to 13-15, now includes GTS variant.
T2 Request for 2017-2018 Honda Civic Type R - 4 BOP Grill #25513wordingwordingT2 Honda Civic Type-R 2017- allows Cuztom Tuning FG-CIV16-V3-TR-BK alternate grill.
T2 Add Clarification to Spec Car Classifications Vehicle Spec #25774wordingwordingT1-T3 spec cars receive clarifications on permitted modifications, documentation requirements, and rule conformance; no performance changes.
T2 Clarify Subframe Bushings Permitted for T2-T4 #25800wordingwordingT2-T4 subframe bushings may now be replaced with non-spherical bushings of any material.
T4 Errors, Omissions, and Updates (Various) #22414wordingwordingT4 Ford Fiesta ST years corrected to 14-; T4 Fiat 124/Abarth Edition years added 16-18; battery rule clarified.
T4 Request for Adjustments to fiat 124 specline #25371inductionfasterT4 Fiat 124 Abarth Edition restrictor changes from 29mm flat plate to 30mm TIR.
T4 Add Clarification to Spec Car Classifications Vehicle Spec #25774wordingwordingT1-T3 spec cars receive clarifications on permitted modifications, documentation requirements, and rule conformance; no performance changes.
T4 Clarify Subframe Bushings Permitted for T2-T4 #25800wordingwordingT2-T4 subframe bushings may now be replaced with non-spherical bushings of any material.
T4 Consider Solo SSC cross over classification into T4 #25802cars addedcars addedScion FR-S and Subaru BRZ 13-16 Solo Spec Coupes added to T4, both 1998cc, 2570 lbs, 225/45/17 tires.
Best is the class's fastest lap in that event's qualifying or race sessions, with the driver who set it, how many cars set a time that session and how close the top five were; a best from fewer than three cars is greyed. With two or more classes, "vs" is the gap of each class's best to the first class's at the same event. "% of T2" is the class's best as a share of T2's best at the same event (100% is level, less is quicker): weather and track condition move every class together, so this compares across years where the raw times do not. It still breaks when T2's own field changes or one session was wet and another dry. Newest event first. The coloured figure under each value is the change from the previous event that has one (green is quicker, red slower). Whole laps only, so events with different sector layouts still compare. Weather and track condition are not accounted for.