This track has been raced on 3 configurations (The Circuit, 2.57 mi; 2.92 mi; 3.02 mi). Laps on different configurations are not comparable, so only events on the 2.57 mile layout are shown; switch above to see the others.
One row per driver and car (a driver who changed cars has a row for each). Each cell is that driver's best in that car across the selected events, with the session it was set in. Best 5-lap stint is the mean of the driver's quickest five consecutive race laps, and consistency is how far their median race lap sat behind their best in that race (small is a driver who does it every lap); both come from the race with the best stint. The fastest in each column is purple, and a car whose best lap is more than 115% of the fastest in its class is greyed (marked ">115%" beside the driver) and left out of the colour scale. Click a column to sort, a row to highlight it.
Theoretical lap is the sum of the best sectors, whichever laps they came from, and never slower than the best lap (where a car's fastest laps were recorded without sector times, its best lap is used). The 115% mark is about the car's best lap only: a car whose best lap is within 115% of the fastest in its class is never marked. Greyed sectors with no theoretical lap mean the sector times on file do not add up to a believable lap. Letters refer to the events above; Q is qualifying, R a race.
Sectors
S1 SF → IM1 0.65 mi
S2 IM1 → IM2 0.75 mi
S3 IM2 → SF 1.17 mi
Spd In → Out 0.03 mi
Sectors are numbered in lap order from start/finish, whatever each event's timing called them; the loop names are SCCA timing's.
By car
Car
Class
Drivers
Lap
Qual
Race
Trap
S1
S2
S3
MG Midget
HP
4
1:40.295Bill Okell
2:04.965Brian Linn
2:03.082Lee Fleming
126.2Lee Fleming
27.543Bill Okell
28.857Bill Okell
43.861Bill Okell
Mazda RX-3
STU
1
1:50.913Tony Rivera
1:50.913Tony Rivera
1:52.737Tony Rivera
135.2Tony Rivera
30.415Tony Rivera
32.456Tony Rivera
47.999Tony Rivera
Mazda Miata
STU/T4
3
1:51.602Whitfield Gregg
2:02.264Whitfield Gregg
2:01.538Whitfield Gregg
128.1Kristina Etherington
30.652Whitfield Gregg
32.263Whitfield Gregg
48.687Whitfield Gregg
BMW M3
STU
1
1:52.380Wilson Powell
1:55.401Wilson Powell
1:53.843Wilson Powell
102.6Wilson Powell
30.577Wilson Powell
32.372Wilson Powell
49.215Wilson Powell
Honda S2000
STU
1
1:53.640Rylan Hazelton
1:55.834Rylan Hazelton
1:53.640Rylan Hazelton
134.8Rylan Hazelton
30.582Rylan Hazelton
32.779Rylan Hazelton
49.779Rylan Hazelton
BMW 330
STU
1
1:56.492Sean Lovett
1:56.492Sean Lovett
1:57.049Sean Lovett
133.7Sean Lovett
31.816Sean Lovett
33.669Sean Lovett
50.941Sean Lovett
Mazda MX-5
STU/T4
2
1:58.339Oscar Jackson
1:58.339Oscar Jackson
1:59.707Oscar Jackson
125.9Dale Shoemaker
32.339Oscar Jackson
34.071Oscar Jackson
51.874Oscar Jackson
Nissan 300ZX
STU
1
1:59.183James Slechta
1:59.183James Slechta
2:00.458James Slechta
132.0James Slechta
32.882James Slechta
34.528James Slechta
51.773James Slechta
Mazda RX-7
STU
1
2:00.248Michael Lewis
2:00.248Michael Lewis
130.4Michael Lewis
32.729Michael Lewis
34.570Michael Lewis
52.880Michael Lewis
Toyota FRS
T4
1
2:01.157Izzy Sanchez
2:01.678Izzy Sanchez
2:01.157Izzy Sanchez
135.5Izzy Sanchez
32.955Izzy Sanchez
34.751Izzy Sanchez
52.742Izzy Sanchez
Scion FR-S
T4
1
2:01.843Tony Kiratsous
2:01.843Tony Kiratsous
2:03.865Tony Kiratsous
133.6Tony Kiratsous
32.895Tony Kiratsous
34.958Tony Kiratsous
53.933Tony Kiratsous
Porsche Boxster
T4
1
2:05.833Lynne Griffiths
2:05.833Lynne Griffiths
2:07.226Lynne Griffiths
122.0Lynne Griffiths
33.699Lynne Griffiths
36.036Lynne Griffiths
55.879Lynne Griffiths
Mazda RX-8
T4
1
2:05.858Steven Kiratsous
2:06.604Steven Kiratsous
2:05.858Steven Kiratsous
105.7Steven Kiratsous
33.416Steven Kiratsous
35.585Steven Kiratsous
55.885Steven Kiratsous
Toyota Yaris
HP
1
2:08.224Bobby Beyer
2:10.927Bobby Beyer
2:08.224Bobby Beyer
92.3Bobby Beyer
34.660Bobby Beyer
37.206Bobby Beyer
56.144Bobby Beyer
Mini Cooper
HP
1
2:09.238Tom Tuttle
2:11.042Tom Tuttle
2:09.238Tom Tuttle
99.0Tom Tuttle
34.631Tom Tuttle
37.306Tom Tuttle
56.479Tom Tuttle
The best any driver of each car managed across the selected events, with who set it. Spellings and model years of the same car are grouped; click a row marked ▸ to see each version. Grouping is worked out from the names, so tell us if two cars are wrongly merged or split.
Rule changes between these events
Cal Club 2023 → Cal Club 2024 2023-02-24 to 2024-02-23
STU E&O STU NA Weight Chart.
#33737 from Eric Heinrich · Rule change · TB 23-03 (2023-03 Fastrack)
fasterSTU minimum weight chart updated: 2450cc to 2595lbs, 2600cc to 2710lbs.
neutralSTU Mazda BP5A classified at 1839 cc maximum displacement, 2023-04-01.
In STU Spec lines, classify Mazda BP5A as follows: STU Maximum Displacement (cc's) Minimum Weight Notes Mazda BP5A 1839 Chart May use engine in its entirety or specific components from the engine.
T4 T4 Mustang Brakes/Swaybar
#34036 from Scotty B White · Rule change · TB 23-04 (2023-04 Fastrack)
fasterT4 Mustang rear sway bar increases from 22mm to 28mm permitted.
In T4 Spec Lines, Ford Mustang (2005-2010), change Notes as follows: "Any sway bar up to F: 35mm and R: 22mm 28mm permitted."
fasterT4 Mini Cooper S all years now run 17-inch wheels, up from 16, with wider rims to 8 inches.
In T4 Spec Lines, Mini Cooper S (02-04), change as follows: Wheel Size: "16 x 7 17 x 8" Add to Notes: "Wheels conforming to B-spec rules are permitted." In T4 Spec Lines, Mini Cooper S (05-06), change as follows: Wheel Size: "16 x 7 17 x 8" Add to Notes: "Wheels conforming to B-spec rules are permitted." In T4 Spec Lines, Mini Cooper S (07-13), change as follows: Wheel Size: "17 x 7 8"
slowerT4 Volkswagen Rabbit 2.5 (06-09) consolidates 06-07 and 08-09 models; Integrated Engineering intake allowed with 25lb penalty.
In T4 Spec Lines, delete Volkswagen Rabbit 2.5 (06-07) in its entirety and change Volkswagen Rabbit 2.5 (08-09) as follows: "Volkswagen Rabbit 2.5 (08 06-09)" Add to Notes: "Integrated Engineering intake IEIMVB1-BK allowed with 25lb penalty."
T4 96-01 Audi a4 2.8 Spring Rate
#34217 from Michael Gordhamer · Rule change · TB 23-06 (2023-05 Fastrack)
fasterT4 Audi A4 2.8 V6 wheels grow to 17x8, tyres to 245, springs now 800lb with 32mm sway bars.
In T4 Spec Lines, Audi A4 V-6 (96-01) / Volkswagen Passat 2.8 V6 (96-05), change as follows: Wheel Size: "16 x 7 17 x 8" Tire Size: "225 245" Notes: "The following items must remain stock: shock/struts (including mounts), original wheels, and transmission differential - unless specified below. 800lb springs allowed. Front and rear sway bars permitted 32mm max."
neutralFord Fiesta HP and Chevrolet Sonic FP model year ranges extended from 2016 to 2019.
In HP, adjust model years of the "Ford Fiesta (11-16)" spec line as follows: "Ford Fiesta (11-16 9)" In FP, adjust model years of the "Chevrolet Sonic (12-16)" spec line as follows: "Chevrolet Sonic (12-16 9)"
HP ITC to FP?
#34286 from David Snow · Rule change · TB 23-06 (2023-07 Fastrack)
neutralHP Volkswagen Rabbit Cabriolet 1780 removed; Rabbit 1588 and 1715 reclassified with engine sizes and year ranges specified.
In HP Spec Lines, Volkswagen Rabbit Cabriolet 1780, delete in its entirely: In HP, Spec Lines, Volkswagen Rabbit, change Title as follows: “Volkswagen Rabbit 1588 (includes Cabriolet / convertible)” “Volkswagen Rabbit 1715 (81-84) (excl. conv.)” “Volkswagen Rabbit GTI 1780 (83-84)”
fasterT4 Mini Cooper S R53 loses 50 lbs, to 2700 for both 02-04 and 05-06 model years.
In T4 Spec Lines, Mini Cooper S (02-04), change Weight as follows: "2750 2700" In T4 Spec Lines, Mini Cooper S (05-06), change Weight as follows: "2750 2700"
HP Correct Intake Valve Size on 1500cc Midget/Spitfire
#34419 from Production Committee · Rule change · TB 23-06 (2023-05 Fastrack)
neutralFP and HP Sprite, Midget, and Spitfire 1500 intake valve size corrected to 36.6/(1.44).
In FP Spec Lines, Austin-Healey Sprite Mk. I, II,III, IV MG Midget Mk I,II, III, IV & 1500, change Intake Valve Size as follows: "(I) 36.65.3/(1.44)" In FP Spec Lines, Triumph Spitfire Mk. IV & 1500, change Intake Valve Size as follows: "(I) 36.65.5/(1.440)" In HP Spec Lines, Triumph Spitfire 1500, change Intake Valve Size as follows: "(I) 36.65.5/(1.440)" In HP Spec Lines, Triumph Spitfire Mk. III & IV 1500, change Intake Valve Size as follows: "(I) 36.65.5/(1.440)"
STU 2022 Toyota GR Cup for STU
#34449 from Club Racing Board · Rule change · TB 23-06 (2023-05 Fastrack)
neutralToyota GR Cup and GR86 Cup (2022-) newly classified in STU at 2700 lbs with 2387 cc engine.
In STU Spec Lines, Toyota GR Cup (2022-), classify as follows:
A specification table follows in the original; it is not shown here.
T4 Rules Clarification for Mazda RX8 Spec Line
#34395 from Colin Koehler · Rule change · TB 23-08 (2023-08 Fastrack)
neutralT3 Mazda RX-8 removes transmission/final drive pairing requirement; T4 removes same requirement, adds Mazdaspeed radiator and coil spring kit.
In T3 Spec Lines, Mazda RX-8 Base/R3/Sport/ GT (04-12), change notes as follows: "Use of 2009 R3 transmission is permitted with alternate gear ratios as listed. R3 transmission must be paired with the listed alternate final drive. Front sway bar permitted 32mm MAX rear sway bar 19 MAX, Front springs max 750, 500 rear. Cold air intake permitted. Header permitted. Aftermarket flywheel and single disc clutch permitted with no weight penalty." In T4 Spec Lines, Mazda RX-8 Base/R3/Sport/ GT (04-12), change notes as follows: "Mazdaspeed radiator #0000-01-8501 allowed. Use of 2009 R3 transmission is permitted with alternate gear ratios as listed. R3 transmission must be paired with the listed alternate final drive. Mazdaspeed coil spring kit #QSEA-34-01Z allowed. 60mm flat plate restrictor required. OE Rear spoiler allowed #F151-V4-920F. OE front air dam allowed #F151-V4-900f-BB. Springs Allowed:
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(F) Mazda Motorsports- 0000- 04-9700-08 or Eibach- 0800.250.0700 (R) Mazda Motorsports- 0000-04-9400-07 or Eibach 0700.250.0400, and helper 0000-04-9926 allowed. Alternate sway bars allowed max 32mm (f) 19mm (r)."
T4 rule book corrections
#34437 from Chi Ho · Rule change · TB 23-08 (2023-08 Fastrack)
fasterT3 BMW 320i (14-15) gains aftermarket intercooler permission; T4 loses it.
In T3 Spec Lines, BMW 320i (14-15), add to Notes the following: "Aftermarket intercooler permitted." In T4 Spec Lines, BMW 320i (14-15), remove from Notes the following: "Aftermarket intercooler permitted."
T4 Ride Height Correction for the T3 Solstice.
#34615 from Joe Aquilante · Rule change · TB 23-08 (2023-08 Fastrack)
neutralT3 Pontiac Solstice GXP minimum ride height set to 3 inches.
In T2 Spec Lines, Pontiac Solstice GXP Coupe / Convertible (07-09), add to Notes the following: "Minimum ride height is 3 inches." In T3 Spec Lines, Pontiac Solstice GXP Coupe / Convertible (07-09), add to Notes the following: "Minimum ride height is 3 inches."
T4 Inclusion of similar car. (CLK 320)
#34626 from Patrick Morgan · Rule change · TB 23-09 (2023-09 Fastrack)
neutralT4 Mercedes Benz CLK 320 Coupe model years expand to 2000-2007, C320 Sedan added.
In T4 Spec Lines, Mercedes Benz CLK 320 Coupe (2004), change as follows: "Mercedes Benz CLK 320 Coupe, C320 Sedan (2004 2000-2007)
HP Larger chokes
#34681 from Brian Downey · Rule change · TB 23-09 (2023-09 Fastrack)
In HP Spec Line, Nissan/Datsun PL510, change Carburetor. No. & Type as follows: "(1) 40 DCN, DCNF w/ 32 4mm choke(s), . or (1) 36mm DCNVH. (2) auto type side draft(s) w/ 32 4mm choke(s) on I.R. manifold @ 90lbs penalty."
HP Porsche 944/924S Rule Change Request
#35002 from Adam Achepohl · Rule change · TB 23-12 (2023-12 Fastrack)
neutralEP Porsche 944/924S combines 2.5L and 2.7L variants with new weights: 2250–2415 lbs depending on engine and year.
In EP Spec Lines, delete the Porsche 944/924S 2.5L (2V) (83-88) spec line entirely, and create a new spec line for Porsche 944/924S 2.5L(2V) 2.7L(2V) (83-89) as follows:
A specification table follows in the original; it is not shown here.
HP FP and HP Toyota Corolla
#35030 from Keith Church · Rule change · TB 23-12 (2023-12 Fastrack)
fasterFP Toyota Corolla 2TC loses 43 lbs to 1810; HP Corolla loses 50–52 lbs to 1910–2006.
In FP Spec Lines, Toyota Corolla 2TC (71-74), change weight as follows: "1853 1810" In HP Spec Lines, Toyota Corolla (71-74), change weight as follows: “1960 1910 * 2009 1958 ** 2058 2006”
HP Weight Reduction for Mazda 626
#35031 from David Reiter · Rule change · TB 23-12 (2023-12 Fastrack)
fasterHP Mazda 626 84-87 weight reduced to 2200 lbs, 2255 lbs, and 2310 lbs across three configurations.
In HP Spec Lines, Mazda 626 (84-87), change weight as follows: "2300 2200 *2358 2255 **2415 2310"
HP Triumph GT6 Adjustments
#35054 from ANTHONY PARKER · Rule change · TB 23-12 (2023-12 Fastrack)
fasterEP Triumph GT6 minimum weight reduced to 1800 lbs.
In EP Spec Lines, Triumph GT6, change weight as follows: "1830 1800"
HP Request to Adjust Weight of 1988-1991 CRX/Civic
fasterHP Honda CRX 1.5 (88-91) weight reduced to 2175 lbs, 2229 lbs, and 2284 lbs across three spec lines.
In HP Spec Lines, Honda CRX 1.5 (88-91), change weight as follows: "2245 2175 *2301 2229 **2357 2284"
T4 Mazda MX-5 ND1 Spec Line Request
#34232 from Josh Smith · Rule change · TB 24-01 (2024-01 Fastrack)
slowerT4 Mazda MX-5 ND1 minimum weight increases 50 lbs to 2700; suspension springs now allow up to 500 lb front, 300 lb rear.
In T4 Spec Lines, Mazda MX-5 Miata/Club/ RF (16-18), change as follows: Weight: "2650 2700" Notes: "Factory bolt-in roll bar/ cross member may be removed to facilitate roll cage installation. The following item(s) must remain stock: transmission differential unless specified below. Retractable hardtop option permitted but must be disabled from moving action and positively fastened. Any OEM or aftermarket hardtop is permitted that retains the OEM roof silhouette, including Mazda hardtop part #0000-07-5902-ND and part #0000-07-5901 (discontinued DG Motorsports). 29mm (f) 16mm (r) sway bars allowed. Suspension package permitted with a 100 lbs. weight increase that includes the following parts: front springs #0000-04-9700-08, rear springs #0000-04-9400-07, helper springs #0000-04-HLPR-EB (optional). Up to 500lb front and 300lb rear
#35038 from Luis Goncalves · Rule change · TB 24-01 (2024-01 Fastrack)
neutralT4 BRZ/FRS/86 spring allowance clarified: 225 lb front and 300 lb rear springs permitted; non-OEM LSD allowed with +50 lbs penalty.
In T4 Spec Lines, Scion FR-S/10 series (13-16), change Notes as follows: "Eibach 82105.320, 4.10582 and SPC 67660 allowed. Eibach 82105.320 sway bar kit allowed. Eibach 4.10582 springs or 225 lb (f) and 300 lb (r) springs allowed. SPC 67660 allowed. Front strut tower brace allowed. Raceseng, part # raceseng-ft86-r-shock-top permitted. Non-OEM limited slip differential allowed with +50 lbs. weight penalty. 55mm flat plate restrictor required. Only 17” wheels permitted." In T4 Spec Lines, Subaru BRZ/ BRZ Limited (13-16), change Notes as follows: "Eibach 82105.320, 4.10582 and SPC 67660 allowed. Eibach 82105.320 sway bar kit allowed. Eibach 4.10582 springs or 225 lb (f) and 300 lb (r) springs allowed. SPC 67660 allowed. Front strut tower brace allowed. Raceseng, part # raceseng-ft86-r-shock-top
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permitted. Non-OEM limited slip differential allowed with +50 lbs. weight penalty. 55mm flat plate restrictor required. Only 17” wheels permitted." In T4 Spec Lines, Subaru BRZ (17-21), change Notes as follows: "Eibach 82105.320, 4.10582 and SPC 67660 allowed. Eibach 82105.320 sway bar kit allowed. Eibach 4.10582 springs or 225 lb (f) and 300 lb (r) springs allowed. SPC 67660 allowed. Front strut tower brace allowed. Raceseng, part # raceseng-ft86-r-shock-top permitted. Non-OEM limited slip differential allowed with +50 lbs. weight penalty. 55mm flat plate restrictor required. Only 17” wheels permitted." In T4 Spec Lines, Toyota 86, GT (17-21), change Notes as follows: "Eibach 82105.320, 4.10582 and SPC 67660 allowed. Eibach 82105.320 sway bar kit allowed. Eibach 4.10582 springs or 225 lb (f) and 300 lb (r) springs allowed. SPC 67660 allowed. Front strut tower brace allowed. Raceseng, part # raceseng-ft86-r-shock-top permitted. Non-OEM limited slip differential allowed with +50 lbs. weight penalty. 55mm flat plate restrictor required. Only 17” wheels permitted."
HP Request to Review Z3 2.5 Spec Line
#35073 from Tim Schreyer · Rule change · TB 24-01 (2024-01 Fastrack)
slowerEP BMW Z3 2.5L weight increases to 2500 lbs, 2563 lbs with turbo, 2625 lbs with supercharger.
In EP spec line, BMW Z3 2.5L, change weight as follows: "2450 2500 *2511 2563 **2573 2625"
HP Parity in HP
#35138 from Kendall Jones · Rule change · TB 24-01 (2024-01 Fastrack)
fasterHP Sprite/Midget Mk I–IV, Mk 1500 compression ratio raised to 12.0:1 at Prep Level 1/2.
In HP Spec Line, Austin-Healey Sprite Mk I, II, III, IV / MG Midget Mk I, II, III, IV & 1500, Prep Level 1/2, change Notes section as follows: "Compression ratio limited to 11 12.0:1"
T4 TSX Allowance
#35219 from Oscar Jackson · Rule change · TB 24-01 (2024-01 Fastrack)
fasterT4 Acura TSX 2004-2008 now allows header.
In T4 Spec Lines, Acura TSX (2004-2008), add to Notes the following: "Header allowed."
HP Spitfire classification
#35224 from Michael Walz · Rule change · TB 24-01 (2024-01 Fastrack)
unclearHP Triumph Spitfire 1500 valve spec changes from 36.6/5.5/(1.44/0) to 36.6/(1.44).
In HP spec line, Triumph Spitfire 1500, make the following change to the Valves column: "(I) 36.65.5/(1.440)"
T4 Requested Update of Model Years of 370Z
#35231 from Richard Kulach · Rule change · TB 24-01 (2024-01 Fastrack)
neutralT3 Nissan 370Z model years expanded to include NISMO Edition through 2022.
In T3 Spec Lines, Nissan 370Z (09-16) / 370Z NISMO Edition (09-13), change model as follows: "Nissan 370Z (09-16) / 370Z NISMO Edition (09-13) ,incl. Nismo (2009-2022)"
HP Miata Alternate Head
#35253 from Don Tucker · Rule change · TB 24-01 (2024-01 Fastrack)
fasterEP Mazda MX-5 1.8L 1990-97 minimum weight drops to 2150 lbs; 1994-97 variants to 2000, 2050, 2100 lbs respectively.
In EP Spec Lines, Mazda MX-5 /Miata 1.8L (90-97), change weight as follows: "2200 2150" Mazda MX-5 /Miata (94-97) "2035 2000 *2086 2050 **2137 2100"
HP Triumph GT6 Adjustments
#35255 from Anthony Parker · Rule change · TB 24-01 (2024-01 Fastrack)
In EP spec line, Triumph GT6, make the following change in the Notes section: "Two (2) 1.75” auto-type carburetors @ 1970 40 lbs. Three (3) Weber 40 DCOE on IR manifold with 28mm chokes @ 1990 lbs. Laycock overdrive, May use 5 speed gearbox w/o overdrive. Three (3) Weber 40mm DCOE w/28mm venturi on individual runner manifold @ 2020 lb."
HP Honda S2000 throttle body
#35272 from Aaron Johnson · Rule change · TB 24-01 (2024-01 Fastrack)
fasterEP Honda S2000 fuel injected throttle body inside diameter increases from 62mm to 64mm.
In EP spec line, Honda S2000, make the following changes to its spec line: Fuel Injected Equipped Throttle Body Inside Diameter: "62 64" Notes: "Comp. Ratio limited to 12.0:1. Valve lift limited to .500”. An adaptor plate can be used to mount the 62mm throttle body from '00-05 to the '06-09 intake manifold. The adaptor plate can be no more than 1.25" thick, and its bore must not exceed the "Fuel Injected Equipped Throttle Body Inside Diameter" maximum spec of 64mm."
HP Front Header/Nose Panel Alternate Material For 84-87 CRX
neutralHP Honda CRX/Si 84-87 front header/nose panel may use alternate material if appearance remains stock.
In HP Spec Lines, Honda CRX/Si (84-87), in Notes, make the following change: "Compression ratio limited to 11.0:1, Valve lift limited to .390”. The front header/nose body panel can be replaced by a replica which may be constructed of an alternate material provided its appearance remains stock."
HP Correction within Triumph TR8 Spec Line
#35315 from Production Committee · Rule change · TB 24-01 (2024-01 Fastrack)
neutralEP Triumph TR8 dry sump allowance moved from carburetor line to notes section.
In EP spec line, Triumph TR8 (78-81), move the "Dry sump allowed" wording to the appropriate location as follows: Carburetor. No. & Type: “Zenith Stromberg carbs or fuel injection. Dry sump is allowed.” Notes: “Comp. Ratio limited to 12.0:1, Valve lift limited to .500”. Dry sump is allowed.”
HP Correction to EP 924S/944 Spec Line
#35317 from Production Committee · Rule change · TB 24-01 (2024-01 Fastrack)
neutralEP Porsche 944/924S 2.5L and 2.7L weight minimums corrected: 2479cc to 2306/2363 lbs, 2681cc to 2358/2415 lbs.
In EP spec line, Porsche 944/924S 2.5L (2V) / 2.7L (2V) (83-89), change Weight as follows:
A specification table follows in the original; it is not shown here.
HP Review Classification of HP Mazda 2
#35318 from Production Committee · Rule change · TB 24-01 (2024-01 Fastrack)
In HP spec line, Mazda 2 (11-14), make the following weight changes: "1920 1995 *1968 2045 **2016 2095"
STU ST Electric-Assisted Steering Systems
#35066 from Jose Osiris Pena · Rule change · TB 24-02 (2024-01 Fastrack)
neutralSTL and STU power steering rules clarified to permit electric-assisted and hydraulic-assisted steering systems.
In GCR, Section 9.1.4.M.16., change as follows: "Power steering may be modified in any of the following ways: a. disconnected , pump, belt, pulley, and hoses may be removed. Hoses may also be looped. Steering rack or box may be modified internally to work without pump. b. an OEM manual steering rack for that model may be fitted c. an electric power steering pump may be fitted d. an OEM electric-assisted steering system may be used or any column mounted electric steering assist may be used e. an OEM hydraulic-assisted steering system may be used"
T4 More Car Lightening Stuff
#35319 from Scotty B White · Rule change · TB 24-02 (2024-02 Fastrack)
In GCR, Section 9.1.9.2.D.1.g.3., change as follows: "Batteries may be replaced provided the replacement is capable of starting the car. Batteries may not be relocated unless noted on the spec line. Batteries must be adequately secured. Battery labeling must conform to 9.3.35.D. with those of an alternate manufacturer, provided they are of similar amp-hour capacity, size and within 10% of OEM weight."
neutralT4 Mazda MX-5 Miata/Club (16-18) and (19-21) permitted to replace 3rd and 4th gears with specific parts.
In T4 Spec Lines, Mazda MX-5 Miata/Club (16-18), add to Notes the following: "3rd and 4th gear may be replaced with the following parts- (0000-02-5803-02, 0000-02-5803-01, 0000-02-5804- 02, 0000-02-5804-01)." In T4 Spec Lines, Mazda MX5 Miata/Club/ RF (19-21), add to Notes the following: "3rd and 4th gear may be replaced with the following parts- (0000-02-5803-02, 0000-02-5803-01, 0000-02-5804- 02, 0000-02-5804-01)."
Applies to Mazda MX-5 on this page: Oscar Jackson
Applies to Mazda Miata on this page: Kristina Etherington, Kayla Etherington
neutralT4 now permits C-Spec cars to compete alongside B-Spec cars.
In GCR, Section 9.1.9.2., change as follows: "Touring car eligibility: Cars are eligible for the class they are listed with a specification line and with the specific allowances permitted. In addition, T2-T4 cars may race one class up in touring classes above their specification line class as long as they are a legal T2-T4 car and conform to their specification line allowances as classified. Cars conforming to C-Spec rules are permitted to compete in Touring 4."
neutralT2-T4 spec lines for 46 cars expire 12/31/24; appeal required to continue.
In T2-T4 Spec Lines, add **This Spec line will expire 12/31/24, Please submit to appeal** to Notes to the following Spec Lines: T2: Acura TL SHAWD (10-13) Audi S4 (12-14) Audi S5 (13-14) Audi TT RS (2018-) Cadillac ATS-V (16-17)
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Cadillac CTS-V (06-07) Chevrolet Camaro SS (98-02) Honda Civic (2017-) Saturn Sky / Convertible (07-09) Subaru Impreza WRX STi (03-07) Subaru Impreza WRX STi (08-11) T3: Audi S4 (10-11) Audi S4 (12-14) Audi TTS Coupe (10-11) Cadillac ATS (2015) Chevrolet Cobalt (05-07) Dodge SRT-4 (03-05) Ford Fiesta ST (2014-) Hyundai Genesis Coupe (2010-) Hyundai Veloster Turbo (18-21) Mazda RX-8 Base/R3/Sport/ GT (04-12) Mini Cooper S (2016-) Subaru WRX (02-05) Toyota Camry (11-15) T4: Acura Integra GS-R VTEC (3 or 4 door) (94-01) Audi A4 V-6 (96-01) / Volkswagen Passat 2.8 V6 (96-05) BMW 320i (14-15) Chevrolet Cobalt SS, Sport Coupe (06-10) Chevrolet Sonic RS (2011-) Chrysler/Dodge Neon ACR SOHC (4 door) (01-02) Dodge Dart (14-15) Dodge/Plymouth Neon ACR SOHC/DOHC (2/4 door) (95-99) Fiat 500 Abarth (12-14) Ford Focus SVT (02-04) Ford Focus ZX4 ST (05-06) Ford Focus (08-11) Ford Mustang V-6 (01-04) Honda Accord LX & EX (03-07) Honda Accord LX-S/EX/EX-L (08-12) Honda Civic Coupe Si (99-00) Honda Civic SI (02-03) Hyundai Elantra GLS (11-12) Hyundai Tiburon V-6 (03-08) Hyundai Veloster Turbo/ R-Spec (14-15) Kia Forte Koup and Sedan LX/EX (10-13) Kia Forte Koup and Sedan SX (10-13) Kia Forte Koup (14-15) Mazda Protégé ES (2000) Mazda Protégé 5 (02-03)
neutralSTU Mini Cooper S SC: alternate LEAP OMICRON hood scoop LEP-OMICRON3 permitted.
In STU Spec Lines, Mini Cooper S SC with Minimum Weight 1900 and 2100, add to Notes: "Alternate LEAP OMICRON hood scoop part # LEP-OMICRON3 is permitted."
In HP Spec Lines, delete the following redundant spec lines in their entirety: Spec line #10 - VW Rabbit Cabriolet 1780 Spec line #3 - VW Scirocco 1588 Spec line #4 - VW Scirocco 1780 (8-valve) (83-88) Spec line #5 - VW Scirocco 1588
neutralT4 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.
In T4 Spec Lines, Mazda RX-8 Base/R3/Sport/ GT (04-12), change Notes as follows: "Mazdaspeed radiator #0000-01-8501 allowed. Mazdaspeed coil spring kit #QSEA-34-01Z allowed. OE Rear spoiler allowed #F151-V4-920F. OE front air dam allowed #F151-V4-900f-BB. Springs allowed 700lb (f) max, 400(r) max. Oil metering pump may be bypassed. Alternate sway bars allowed max 32mm (f) 19mm (r)."
T4 Allow T4 and T3 RX8 to Disable/Remove Factory Oil Inj.
#35761 from David Mead · Rule change · TB 24-05 (2024-05 Fastrack)
unclearT3 and T4 Mazda RX-8 may remove or disable factory oil injection system.
In T3 Spec Lines, Mazda RX-8 Base/R3/Sport/ GT (04-12), add to Notes as follows: "OEM oil injection system may be removed or disabled." In T4 Spec Lines, Mazda RX-8 Base/R3/Sport/ GT (04-12), add to Notes as follows: "OEM oil injection system may be removed or disabled."
T4 2023 ND2 Miata Classification and Allowances
#35837 from Coyote Black · Rule change · TB 24-05 (2024-05 Fastrack)
slowerT4 Mazda MX5 Miata/Club/RF year range extended to 2024, suspension package permitted with 100 lbs weight increase.
In T4 Spec Lines, Mazda MX5 Miata/Club/ RF (19-21), change Year as follows: "(19-21 24)" In T4 Spec Lines, Mazda MX5 Miata/Club/ RF (19-21), add to Notes as follows: "Suspension package permitted with a 100 lbs. weight increase that includes the following parts: front springs #0000-04-9700- 08, springs up to 500lb front and 300lb rear allowed. Mazda tower brace 0000-04-5626 allowed."
T4 Errors and Omissions for 06-09 VW Rabbit Rotor
#35851 from Andrew Burke · Rule change · TB 24-05 (2024-05 Fastrack)
fasterT4 Volkswagen Rabbit 2.5 (06-09) front brakes increase from 228 to 288 vented disc.
neutralHP Honda CRX/Si 84-87 plastic panels can be replaced with replica alternate material if stock appearance maintained.
In HP spec line "Honda CRX/Si (84-87)", make the following change to the Notes section: "The plastic OE front header/nose body panel, lower rocker side-skirt, and lower door cap panel can be replaced by a replica, which may be constructed of an alternate material, provided its appearance remains stock."
T4 Driveshafts
#35916 from Scotty B White · Rule change · TB 24-05 (2024-05 Fastrack)
slowerT2, T3, T4 driveshafts may use alternative materials or one-piece units; non-OEM adds 25 lbs.
In GCR Section 9.1.9.2.D.4.b., add the following: "6. T2-T3- Driveshafts may be replaced with alternative materials ie. carbon fiber, aluminum, steel. Two-piece driveshafts may be replaced with one-piece units. If non-OEM driveshaft is used, add 25 lbs."
fasterT4 Mazda MX-5 Miata/Club 16-18 removes differential stock requirement, allows up to 500lb front and 300lb rear springs.
In T4 Spec Lines, Mazda MX-5 Miata/Club (16-18), change Notes as follows: "Factory bolt-in roll bar/ cross member may be removed to facilitate roll cage installation. The following item(s) must remain stock: transmission differential unless specified below. Retractable hardtop option permitted but must be disabled from moving action and positively fastened. Any OEM or aftermarket hardtop is permitted that retains the OEM roof silhouette, including Mazda hardtop part #0000-07-5902-ND and part #0000-07-5901 (discontinued DG Motorsports). 29mm (f) 16mm (r) sway bars allowed. Suspension package permitted with a 100 lbs. weight increase that includes the following parts: front springs #0000- 04-9700-08, rear springs #0000-04-9400-07, helper springs #0000-04-HLPR-EB (optional). Up to 500lb front and 300lb rear springs allowed. Mazda Motorsports Header part #0000-06-5410 allowed. Mazda tower brace 0000-04-5626 allowed."
Applies to Mazda MX-5 on this page: Oscar Jackson
Applies to Mazda Miata on this page: Kristina Etherington, Kayla Etherington
fasterT4 Mini Cooper S 02-04 and 05-06 now allow Milltek exhaust manifold #SSXM459 and 25mm rear sway bar.
T4 Spec Lines, Mini Cooper S (02-04), add to Notes the following: "Milltek exhaust manifold #SSXM459 allowed. 25mm rear sway bar allowed." T4 Spec Lines, Mini Cooper S (05-06), add to Notes the following: "Milltek exhaust manifold #SSXM459 allowed. 25mm rear sway bar allowed."
HP Clean-up Multiple EP RX-8 Spec Lines In EP
#36156 from Production Committee · Rule change · TB 24-06 (2024-06 Fastrack)
neutralEP Mazda RX-8 (04-11) alternate spec line removed; one primary line remains.
Spec Lines, make the following changes to the two Mazda RX-8 spec lines. Remove spec line entirely: Mazda RX-8 (04-11) Remove the wording "alternate": Mazda RX-8 (04-11)(alternate) Spec Mazda (SM/SMX) None.
T4 Mustang T2/T3
#35877 from Scotty B White · Rule change · TB 24-07 (2024-07 Fastrack)
unclearFord Mustang GT 5.0L and V6 now permit Track/Performance Package parts in T2 and T3.
In T2 Spec Lines, Ford Mustang GT 5.0L (15-17), add to Notes as follows: "Track/Performance Package parts permitted." In T2 Spec Lines, Ford Mustang GT 5.0L (2018-), add to Notes as follows: "Track/Performance Package parts permitted." In T3 Spec Lines, Ford Mustang V6 (15-17), change Notes as follows: "Track/Performance package allowed."
T4 Homologation of car to T4
#36030 from Patrick E Morgan · Rule change · TB 24-07 (2024-07 Fastrack)
neutralMercedes C300 4Matic 2008-2011 homologated to T4 at 3,725 lbs with 18x8.5 wheels, 245 max tires, 3.27 final drive.
In T4 Spec Lines, Mercedes C300 4Matic (2008-2011), classify as follows:
A specification table follows in the original; it is not shown here.
T4 T2-T4 Driveshaft Mistake...?
#36050 from Scotty B White · Rule change · TB 24-07 (2024-07 Fastrack)
fasterT2-T4 Ford Mustangs: remove 25 lbs penalty for non-OEM driveshaft, clarify alternate driveshaft allowances.
In GCR Section 9.1.9.2.D.4.b.6., remove as follows: "If non-OEM driveshaft is used, add 25 lbs." In T2 Spec Lines, Ford Mustang V6 (11-14), change Notes as follows: "Driveshaft from Alternate metallic driveshaft is allowed." In T2 Spec Lines, Ford Mustang Boss 302 (12-13), change Notes as follows: "Alternate metallic driveshaft is allowed." In T2 Spec Lines, Ford Mustang GT 5.0L (11-14)ki, change Notes as follows: "Alternate metallic driveshaft is allowed."
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In T2 Spec Lines, Ford Mustang GT 5.0L (15-17), change Notes as follows: "Alternate metallic driveshaft is allowed." In T2 Spec Lines, Ford Mustang GT 5.0L (2018-), change Notes as follows: "Alternate metallic driveshaft is allowed." In T2 Spec Lines, Ford Mustang Coupe GT & Shelby GT 4.6L (05-10), change Notes as follows: 'An Aluminum driveshaft is allowed." "Alternate metallic driveshaft is allowed." In T3 Spec Lines, Ford Mustang Coupe GT & Shelby GT 4.6L & Cal. Special (05-10), change Notes as follows: "An Aluminum driveshaft is allowed." "Alternate metallic driveshaft is allowed." In T3 Spec Lines, Ford Mustang V6 (11-14), change Notes as follows: "Driveshaft from Alternate metallic driveshaft is allowed."
T4 MINI Cooper S Spec Lines Corrections.
#36086 from David Oliveira · Rule change · TB 24-07 (2024-07 Fastrack)
neutralT4 Mini Cooper S (02-04) deleted; (05-06) model year corrected to R53; (07-13) R56 simplified specs; (2014-2023) added with spring rates.
In T4 Spec Lines, Mini Cooper S (02-04), delete spec line in its entirety. In T4 Spec Lines, Mini Cooper S (05-06), change Model as follows: "Mini Cooper S R53 (0205-06)" In T4 Spec Lines, Mini Cooper S (07-13), change Model and Notes as follows: "Mini Cooper S R56 (07-13)" Notes: "The following items must remain stock: shock/struts (including mounts), original wheels, and transmission differential - unless specified below. Convertible model not allowed. Factory optional limited slip differential allowed. JCW struts (F) 31 31 6 768 410 (R)33 52 6 768 412, springs (F)31 33 6 768 415 (R)33 53 6 768 418. May de-camber
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wheels by the use of slotted adjusters at the top of the strut mounting plates. They shall be located on the existing chassis structure, utilizing the manufacturers original bolt holes and may not serve as reinforcement for that structure. Any spring up to a maximum spring rate of 500 lbs. front and 800 lbs. rear may be used. Wheels conforming to B-spec rules are permitted." In T4 Spec Lines, Mini Cooper S (2016-), change Model and add to Notes as follows: "Mini Cooper S (20142016-2023)" Notes: "Convertible model not allowed. Any spring up to a maximum spring rate of 500lbs. front and 800lbs. rear may be used."
T4 Allow Removal of Sound Tubes
#36130 from Coyote Black · Rule change · TB 24-07 (2024-07 Fastrack)
fasterT4 OEM intake chambers, resonators and acoustic devices may be removed if ports sealed and before restrictor.
In GCR Section 9.1.9.2.D.1.b., add the following: "2. OEM intake- Chambers, resonators and acoustic devices may be removed, provided; that their ports are located prior to any required restrictor, their ports are completely sealed, and that the part serves no other purpose."
T4 B8/8.5 Audi S4 T3 and T2
#36195 from Brian Leib · Rule change · TB 24-07 (2024-07 Fastrack)
neutralAudi S4 (2000-2002) moves to T3 with 3400 lbs minimum weight, 38mm turbo inlet restrictor required.
In T3 Spec Lines, Classify Audi S4 (2000-2002) as follows and allow the T2 spec line to expire.
A specification table follows in the original; it is not shown here.
fasterT4 Chevrolet Camaro V-6 (96-02) weight reduced from 3250 lbs to 3150 lbs.
In T4 Spec Lines, Chevrolet Camaro V-6 (96-02), change weight as follows: "3250 3150"
STU RWD Turbo Disadvantage
#36255 from David Fiorelli · Rule change · TB 24-08 (2024-08 Fastrack)
fasterSTU RWD turbo cars no longer required to reduce restrictor by 1 mm from table.
In GCR, Section 9.1.4.1.H.3 - Inlet Restrictor (mm) Minimum Weight (lbs) table, change as follows: "RWD cars must reduce restrictor 1 mm from this table"
fasterHP Sprite and Midget 1275cc and 1098cc Level 2 compression ratio raised to 12.0:1.
In HP Spec Lines, Austin-Healey Sprite MkI, II, III, IV MG Midget (ALL) - Level 2 - 1275cc, change Notes as follows: "(Effective 11/1/2024) Compression ratio limited to 11 12.0:1" In HP Spec Lines, Austin-Healey Sprite MkI, II, III, IV MG Midget (ALL) - Level 2 - 1098cc, change Notes as follows: "(Effective 11/1/2024) Compression ratio limited to 11 12.0:1"
HP Request for Classification of 1989-1994 Suzuki Swift GT 16V Twin
slowerSTU Mini Cooper S SC 1900 restricts to 2.565 diameter pulley; 2100 allows 2.285 diameter pulley.
In STU Spec Lines, Mini Cooper S SC, add to notes: 1900: "Stock supercharger pulley. 2.565 diameter." 2100: "JCW Pulley permitted. May run a 2.285 diameter pulley."
neutralT4 Honda Civic Si 06-11 permitted to use LSD per category rules.
In T4 Spec Lines, Honda Civic Si (06-11), add to Notes the following: "LSD is permitted according to category rules."
T4 Redundant Verbiage Regarding Mustang Spec Lines for Driveshaft
#36484 from David Mead · Rule change · TB 24-12 (2024-12 Fastrack)
neutralT2 and T3 Mustang spec lines remove redundant driveshaft alternate/aluminum allowance wording.
In T2 Spec Lines, change Notes as follows: Ford Mustang V6 (11-14): "Alternate driveshaft is allowed." Ford Mustang Boss 302 (12-13): "Alternate driveshaft is allowed." Ford Mustang GT 5.0L (11-14): "Alternate driveshaft is allowed." Ford Mustang GT 5.0L (15-17): "Alternate driveshaft is allowed." Ford Mustang GT 5.0L (2018-): "Alternate driveshaft is allowed. Springs up to 800#/in front and rear permitted. Alternate metallic driveshaft permitted." Ford Mustang Coupe GT & Shelby GT 4.6L (05-10): "Alternate driveshaft is allowed."
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In T3 Spec Lines, change Notes as follows: Ford Mustang Coupe GT & Shelby GT 4.6L & Cal. Special (05-10): "Alternate driveshaft is allowed." Ford Mustang V6 (11-14): "Alternate driveshaft is allowed." Ford Mustang V6 (05-10): "An Aluminum driveshaft is allowed."
fasterT4 Mini Cooper S R53 now allows Alta 15% Pulley #AMPENG20X.
In T4 Spec Lines, Mini Cooper S R53 (02-06), add to Notes as follows: "Alta 15% Pulley #AMPENG20X allowed."
T4 Allowable Wheel Offset
#36855 from Robert Maples · Rule change · TB 24-12 (2024-12 Fastrack)
neutralT4 removes restriction on aftermarket wheel weight minimum of 15 lbs.
In GCR Section 9.1.9.2.D.7. Wheels and Tires, change as follows: "a. Wheels 1. Any type wheel suitable for competition may be used, provided: a. Any wheel not exceeding the specified diameter and rim width on the vehicle’s specification line may be used. Each wheel, measured without weights, must weigh at least 15 lbs. b. Wheels are permitted any offset provided the tire tread (that portion of the tire that contacts the ground) does not protrude beyond the fender opening when viewed from 9.1.9.2.Touring (T2-T4) Category Specifications GCR - 660 the top perpendicular to the ground, unless specified differently on the individual spec line for that car. To determine compliance the vehicle should be
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rolled through a powdered substance, as raced with driver, in order to indicate the tire tread contact patch under static conditions. When a maximum tire size is listed on a vehicle’s specification line, aspect ratio is open and any tire may be used that does not exceed the stated maximum section width. c. Cars equipped with lug bolts may convert to wheel studs and lug nuts. d. Wheel studs may be replaced with longer studs as necessary to fit optional wheels. Wheel spacers may be used for purposes of adjusting track. e-T4 only: (unless specified on spec line) Any aftermarket wheel with a minimum weight of 15 lbs allowed."
neutralT2, T3, T4 fuel cell installations may remove charcoal canisters, emissions valves, and sensors.
In GCR, Section 9.1.9.2.D.1.c. add the following: "5. Removal of ancillary fuel tank equipment charcoal canisters, emissions valves, and sensors allowed for OEM or aftermarket fuel cell installations."
neutralT2, T3, T4 brake component wording clarified: 2-piece rotors allowed in T2 within 5% OE diameter, T3 within 2% OEM diameter.
In GCR, Section, 9.1.9.2.D.6. Brakes, change as follows: "a. Components 1. The make and material of brake pads and linings may be changed. 2. Brake fluid may be substituted with any brake fluid. 3. Brake rotor dust shields may be removed or replaced to accommodate brake ducts. 4. Flexible rubber brake lines may be replaced with Teflon lined, metal braided hoses. 5. Any brake ducts are permitted, but they must serve no other purpose. Fender liners may be modified solely for routing and attachment of brake ducts. Duct intake openings may be created by the opening of 2 sections up to 14.5 square inches each in
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the front fascia. The stock headlamp location is not permitted for brake ducting. Two alternative duct openings may be created by the removal of the fog lights or 2 sections up to 14.5 square inches each of stock false grills originally located in the front fascia. 6. Stock replacement brake rotors may be obtained from sources other than the manufacturer provided they are the exact equivalent of the stock rotors. In T2 only - 2-piece rotors with ferrous metal rotor disks and aluminum hats are allowed, must be within 5% of OE diameter. In T3 only - 2-piece front rotors with ferrous metal rotor disks and aluminum hats are allowed, must be within 2% of OEM diameter. Drilled and slotted rotors are permitted. 7. Parking brakes, mechanisms, and actuating components may be removed. 8. Brake vacuum reservoirs sized 0.50 gallons or smaller are permitted. The port or fitting at the vacuum source may not be modified, enlarged or relocated. The vacuum reservoir and brake booster must be a closed system."
neutralT2, T3, T4 fuel cell cars may remove charcoal canisters, emissions valves, and sensors.
In GCR, Section, 9.1.9.2.D.1.c., add the following: "5. Removal of ancillary fuel tank equipment; charcoal canisters, emissions valves, and sensors allowed for OEM or aftermarket fuel cell installations."
STU Request to Remove Miata Hubs from General category
#37138 from Christopher Childs · Rule change · TB 24-12 (2024-12 Fastrack)
neutralSTL/STU: 90-05 Mazda Miata alternate front wheel hubs moved from General to specific part approval.
In GCR, Section 9.1.4.M.18., change as follows: "18. Allow alternate front wheel front hubs, Mazda Motorsports Development Part #0000-04-5HUB-S1, for the 90-05 Mazda Miata: Mazda Motorsports Development Part #0000-04-5HUB-S1."
#37140 from Chris Braunlich · Rule change · TB 24-12 (2024-12 Fastrack)
neutralT3 and T4 Mazda RX-8 and MX-5 permit transmission kit #0000-02-5700.
In T4 Spec Lines, add the following to Notes: Mazda RX-8 Base/R3/Sport/ GT (04-12): "Transmission kit # 0000-02-5700 permitted. Mazda MX-5 / Club Model (06-15): "Transmission kit # 0000-02-5700 permitted." In T3 Spec Lines, add the following to Notes: Mazda MX-5 / Club Model (06-15): "Transmission kit # 0000-02-5700 permitted." Mazda RX-8 Base/R3/Sport/ GT (04-12): "Transmission kit # 0000-02-5700 permitted."
STU BMW N54/N55 Engine Allowance
#37146 from Martin Sarukhanyan · Rule change · TB 24-12 (2024-12 Fastrack)
slowerSTU BMW N54/N55 turbo inlet restrictors now required per GCR definition; turbo swapping prohibited.
"Turbo inlet restrictors designed per GCR Appendix F Technical Glossary definition of “Turbo Inlet Restrictor” may be required; see table 9.1.4.1.H.h.2 3. Swapping of turbochargers between engine makes and models is prohibited. Supercharged cars may be approved on a case-by-case basis; twin turbo engines are allowed on a case-by-case basis only. Contact the Road Racing Technical Office for details. Twin turbo engines may be converted to single turbo using one of the allowed alternate turbos (see 9.1.4.1.H.3 2). Aftermarket turbocharger and supercharger kits will be allowed on a case-by-case basis.
T4 Move Spec Boxster to T4
#37158 from Rob Piekarczyk · Rule change · TB 24-12 (2024-12 Fastrack)
neutralPorsche Spec Boxster moves to T4, minimum weight 2750 lbs, requires 3 Super Tour events before Runoffs eligibility.
In T4 Spec Lines, classify Porsche Spec Boxster, as follows:
A specification table follows in the original; it is not shown here.
Applies to Porsche Boxster on this page: Lynne Griffiths
HP MINI Cooper Spec Line Correction - Rear Brake Rotor Diameter
#37176 from Robert Bax · Rule change · TB 24-12 (2024-12 Fastrack)
neutralHP Mini Cooper 02-06 rear brake rotor increases from 239/9.4 mm/in to 259/10.2.
In HP Spec Lines, Mini Cooper (02-06), change Brakes Std.mm/(in.) as follows: "(F) 276/(10.9) Vented Disc (R) 239/(9.4) 259/(10.2) Solid Disc"
Applies to Mini Cooper on this page: Tom Tuttle
T4 3.7 Mustangs to T4
#37188 from Scotty B White · Rule change · TB 24-12 (2024-12 Fastrack)
neutralFord Mustang V6 (05-14) newly classified to T4 with 50mm restrictor, 3400 lbs minimum weight.
In T4 Spec Lines, classify Ford Mustang V6 (05-14), as follows:
A specification table follows in the original; it is not shown here.
T4 BMW 320i Spec Line
#37204 from chi ho · Rule change · TB 24-12 (2024-12 Fastrack)
neutralT4 BMW 320i 14-15 Spec Line expires 12/31/24 removed; Turner Motorsports intercooler #024703TMS02 allowed.
In T4 Spec Lines, BMW 320i (14-15), change Notes as follows: "**This Spec line will expire 12/31/24, Please submit to appeal** Turner Motorsports intercooler #024703TMS02 allowed."
T4 MX5 2006-2015 NC Help
#37221 from Richard Mooney · Rule change · TB 24-12 (2024-12 Fastrack)
unclearUnable to summarize: rule changes specified in letter #37281, not provided.
Thank you for your letter. Please see changes in letter #37281 in current Fastrack.
T4 Classification for a 2005 Cadillac CTS 3.6 liter 6 speed manual
fasterT4 Honda Civic Si 06-11 minimum weight drops 50 lbs to 2900, restrictor clarified.
In T4 Spec Lines, Honda Civic Si (06-11), change as follows: Required Restrictor: "55mm flat plate restrictor required." Min Weight: "2950 2900" Notes: "The following items must remain stock: transmission differential - unless specified below. 55mm flat plate restrictor required. LSD IS PERMITTED ACCORDING TO CATEGORY RULES"
neutralT4 NC MX-5 06-15 removes SM5 suspension allowance, clarifies Mazda Motorsports LSD part number, adds weight penalty for other LSDs.
In T4 Spec Lines, Mazda MX-5 / Club Model (06-15), change Notes as follows: "Factory bolt-in roll bar/cross member may be removed to facilitate roll cage installation. MSR option permitted. Suspension package permitted with a 100 lbs. weight increase that includes the following parts: front spring mount PT#-0000-04-5259, front springs #0000-04-9700-08, rear spring mount PT#-0000-04-5258, rear springs #0000-04-9400-07, helper springs #0000-04-HLPR- EB (optional), Swaybar kit – PT#-0000-04-5306-EB that includes (front sway bar kit PT#0000-04- 5306-FT, rear sway bar kit PT#- 0000-04-5306-RR), offset front camber bushing PT#-0000-04- 5407-NC. Mazda Motorsports cold air intake part #0000-06-5150- KT allowed. Mazda Motorsport RX8 rear Hub Conversion kit part number 0000-04-5811-KT allowed, RX8 front hubs PT# F189-33- 04X allowed. The SM5 suspension (only) is allowed with a 100 lbs. weight increase. Allow Mazda header part numbers 0000-06-
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5407 or 0000-06-5407-NC. Any OEM or aftermarket hardtop is permitted that retains the OEM roof silhouette, including Mazda hardtop and part #0000-07-5901- CC. Aftermarket power steering reservoir is allowed. Mazda Transmission kit part # 0000-02- 5700. Mazda Motorsports LSD #3265 5 0000-02-5564 permitted without penalty. Any other non-OEM limited slip differential allowed with +50 lbs. weight penalty. Front spoiler permitted (NF51-V4-900F)."
Applies to Mazda MX-5 on this page: Oscar Jackson
T4 ND MX-5 wheel allowance
#37279 from Josh Smith · Rule change · TB 24-12 (2024-12 Fastrack)
unclearT4 Mazda MX-5 Miata/Club (16-18) wheel size changes to 17 x 7.5 inches.
In T4 Spec Lines, Mazda MX-5 Miata/Club (16-18), change Wheel Size as follows: "17 x 7.5"
Applies to Mazda MX-5 on this page: Oscar Jackson
Applies to Mazda Miata on this page: Kristina Etherington, Kayla Etherington
In T2, Effective 1/1/2025, delete for following Spec Lines in their entirety: "Acura TL SHAWD (10-13) Audi S4 (12-14) Audi S5 (13-14) Audi TT RS (2018-) Cadillac ATS-V (16-17) Cadillac CTS-V (06-07) Chevrolet Camaro SS (98-02)
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Honda Civic Type-R (2017-) Saturn Sky / Convertible (07-09)" In T3, Effective 1/1/2025, delete for following Spec Lines in their entirety: "Audi TTS Coupe (10-11) Cadillac ATS (2015) Chevrolet Cobalt (05-07) Dodge SRT-4 (03-05) Ford Fiesta ST (2014-) Hyundai Genesis Coupe (2010-) Hyundai Veloster Turbo (18-21) Mini Cooper S (2016-) Toyota Camry (11-15)" In T4, Effective 1/1/2025, delete for following Spec Lines in their entirety: "Acura Integra GS-R VTEC (3 or 4 door) (94-01) Audi A4 V-6 (96-01) / Volkswagen Passat 2.8 V6 (96-05) Chevrolet Cobalt SS, Sport Coupe (06-10) Chevrolet Sonic RS (2011-) Chrysler/Dodge Neon ACR SOHC (4 door) (01-02) Dodge Dart (14-15) Dodge/Plymouth Neon ACR SOHC/DOHC (2/4 door) (95-99) Fiat 500 Abarth (12-14) Ford Focus SVT (02.5-04) Ford Focus ZX4 ST (05-06) Ford Focus (08-11) Ford Mustang V-6 (01-04) Honda Accord LX & EX (03-07) Honda Accord LX-S/EX/EX-L (08-12) Honda Civic Coupe Si (99-00) Honda Civic SI (02-03) Hyundai Elantra GLS (11-12) Hyundai Tiburon V-6 (03-08) Hyundai Veloster Turbo/ R-Spec (14-15) Kia Forte Koup and Sedan LX/EX (10-13) Kia Forte Koup and Sedan SX (10-13 Kia Forte Koup (14-15) Mazda Protégé ES (2000) Mazda Protégé 5 (02-03) Mazda6 s (03-07) Mitsubishi Eclipse GT (00-05) Nissan Sentra SER (02-03) Pontiac Firebird V-6 (96-02) Scion tC (03-07) Subaru Impreza (non-turbo) (04-06) Toyota Celica GT (00-05) Toyota Celica GTS/GT (00-05) Volkswagen Golf TDI (2010) Volkswagen Passat (12-14) Volkswgen Passat TDI (12-14) Volkswgen Passat 1.8T (2014-)"
HP Request to Update 1988-1991 Civic to Match 1988-1991 CRX
fasterHP Honda Civic 1.5 88-91 weight reduced to 2175 lbs base, 2229 lbs with one asterisk, 2284 lbs with two asterisks.
In HP SPEC LINES, Honda Civic 1.5 (88-91), change Weight as follows: "2245 2175 *2301 2229 **2357 2284"
STU Merger GT3 to STU
#37486 from Club Racing Board · Rule change · TB 25-01 (2025-01 Fastrack)
neutralSTU-GT3 reclassified as STU-GT3U effective January 1, 2026.
In STU, Table C, change STU-GT3 charge as follows: "(Effective January 1, 2026) TABLE C: STU-GT3U"
STU GT3 TCR Tire allowance
#37494 from Club Racing Board · Rule change · TB 25-01 (2025-01 Fastrack)
slowerSTU GT3 TCR gains 275-width tire option with 100 lb weight penalty, but not in A compound.
In STU, Table C, GT3 TCR, add to Notes the following: "May run DOT approved tire with maximum section width of 275 with 100 pound weight adder. May not run A compound with 275."
neutralT4 Ford Mustang V6 (05-14) final drive set to 3.45, GT/CS front bumper cover permitted with front fascia.
In T4 Spec Lines, Ford Mustang V6 (05-14), change as follows: Final drive: "3.45" Notes: "GT/CS front bumper cover #AR3Z-17D957-BA, allowed if used with front fascia."
T4 Request to Classify Club Spec in Appropriate Touring Classes
#37523 from Andrew Benagh · Rule change · TB 25-02 (2025-02 Fastrack)
neutralFord SCCA Club Spec Mustang classified T3 at 3350 lbs with driver; Mazda SCCA Club Spec MX-5 classified T4 at 2500 lbs with driver.
In T3 Spec Lines, classify Ford SCCA Club Spec Mustang (CSM) as follows:
A specification table follows in the original; it is not shown here.
In EP Spec Lines, add to Notes as follows: BMW Z3 2.5LL "(Effective 2/21/2025) 52mm Flat Plate Intake Restrictor is required." BMW Z3 2.8L (97-00): "(Effective 2/21/2025) 55mm Flat Plate Intake Restrictor is required." BMW 328i/is E36 (96-99): "(Effective 2/21/2025) 58mm Flat Plate Intake Restrictor is required." BMW 328i/ci E46 (01-06): "(Effective 2/21/2025) 58mm Flat Plate Intake Restrictor is required." BMW 325i/is E46 (01-06): "(Effective 2/21/2025) 56mm Flat Plate Intake Restrictor is required." BMW 325i/is E-36 (92-95): "(Effective 2/21/2025) 56mm Flat Plate Intake Restrictor is required." BMW 325is M-Technic (1994): "(Effective 2/21/2025) 56mm Flat Plate Intake Restrictor is required."
Cal Club 2025 → Cal Club 2026 2025-02-22 to 2026-02-21
HP Request Competition Adjustment to BMW Z3 2.5L
#37120 from Tim Schreyer · Rule change · TB 25-01 (2025-01 Fastrack)
slowerEP BMW Z3 and 3-series models get smaller intake restrictors: Z3 2.5L to 52mm, Z3 2.8L to 55mm, 328i to 58mm, 325i to 56mm.
In EP Spec Lines, change Notes as follows: BMW Z3 2.5LL "(Effective 3/1/2025) 56mm 52mm Flat Plate Intake Restrictor is required." BMW Z3 2.8L (97-00): "(Effective 3/1/2025) 59mm 55mm Flat Plate Intake Restrictor is required." BMW 328i/is E36 (96-99): "(Effective 3/1/2025) 62mm 58mm Flat Plate Intake Restrictor is required." BMW 328i/ci E46 (01-06): "(Effective 3/1/2025) 62mm 58mm Flat Plate Intake Restrictor is required." BMW 325i/is E46 (01-06): "(Effective 3/1/2025) 60mm 56mm Flat Plate Intake Restrictor is required." BMW 325i/is E-36 (92-95): "(Effective 3/1/2025) 60mm 56mm Flat Plate Intake Restrictor is required." BMW 325is M-Technic (1994): "(Effective 3/1/2025) 60mm 56mm Flat Plate Intake Restrictor is required."
HP Interpretation of Production Rules on Mirrors
#37235 from Lawrence Slivinski · Rule change · TB 25-03 (2025-03 Fastrack)
neutralEP, FP, HP: interior or exterior mirrors meeting rule 9.3.36 now permitted.
In GCR, add new rule as Section 9.1.5.E.10.f: "Any interior or exterior mirror(s) that meets rule 9.3.36 may be used."
STU BMW N54/N55 Engine Allowance Follow Up
#37447 from Martin Sarukhanyan · Rule change · TB 25-03 (2025-03 Fastrack)
neutralSTU BMW N54/N55 3.0L classified at Chart +3% minimum weight; N54 twin turbo not allowed.
In STU Spec Lines, Table A, classify BMW N54/N55 as follows: STU Maximum Displacement (cc's) Minimum Weight Notes BMW N54/N55 3.0 Chart +3% (DI) Short blocks, heads, and intakes may be freely swapped within these engine designations. N54 twin turbo not allowed
HP HP Class Adjustments
#37459 from Production Committee · Rule change · TB 25-01 (2025-01 Fastrack)
slowerHP Mazda 2 11-14 base weight up 50 lbs to 2045; all VW 80s models up 50 lbs to 2150 base.
#37466 from Michael Unger · Rule change · TB 25-03 (2025-03 Fastrack)
fasterEP Honda S2000 1997cc base loses 75 lbs to 2375; 2157cc base loses 60 lbs to 2450.
In EP, Spec Lines make the following weight changes:
A specification table follows in the original; it is not shown here.
HP Mazda 1999 Miata 1.8L
#37488 from Joe Carr · Rule change · TB 25-03 (2025-03 Fastrack)
fasterEP Mazda MX-5/Miata 99-05 minimum weight drops to 2100 lbs, 2153 lbs with power adder, 2205 lbs with two adders.
In EP Spec Lines, make the following weight change: Mazda MX-5 /Miata (99-05): "2150 2100 *2204 2153 **2258 2205"
HP MINI Cooper (07-13) Spec Line Correction: Errors and Omissions
#37560 from Robert Bax · Rule change · TB 25-03 (2025-03 Fastrack)
slowerHP Mini Cooper 07-13 engine corrected to DOHC; valve lift limit reduced to 0.390 inches.
In HP Spec Lines, Mini Cooper (07-13) (includes 09-15 convertible and 12-15 Coupe), change as follows: Engine Type: "4 Cyl SOHC DOHC" Notes: "Compression ratio limited to 11.0:1, Valve lift limited to .450”.390"."
Applies to Mini Cooper on this page: Tom Tuttle
STU STU Mini Cooper pulley size clarification re: letter #36980
fasterHP Ford Festiva 88-93 minimum weight drops to 1600 lbs, variants to 1640 and 1680 lbs; compression ratio raised to 11.0:1.
In HP Spec Lines "Ford Festiva (88-93)" change as follows: Weight: "1700 1600 *1743 1640 **1785 1680" Notes: "Compression ratio limited to 10.5 11.0:1. Valve lift limited to .450”."
STU Wheel Size Inconsistency
#38018 from David Fiorelli · Rule change · TB 25-05 (2025-05 Fastrack)
neutralSTU wheel width rules clarified: cars ≤2,850 lbs max 8 inches, cars >2,850 lbs max 9 inches.
In GCR, Section 9.1.4.1.F.1., change as follows: "Wheels may not exceed 18 inches in diameter. or 8.0 inches in width for vehicles 2950 lbs. and under minimum allowed race weight. Vehicles over 2850 minimum allowed race weight may use a 9 inch wide wheel. Cars equal to or less than 2,850 lbs. minimum allowed race weight may not use wheels wider than 8 inches. Cars greater than 2,850 lbs. minimum allowed race weight may not use wheels wider than 9 inches."
T4 Correct Ring and Pinion Ratio to T3, Sorry I Mean T4 3.7 V6 Stang
#38041 from David Mead · Rule change · TB 25-05 (2025-05 Fastrack)
neutralT4 Ford Mustang V6 05-14 allows GT 8.8 rear axle or 7.5 axle with 3.45:1 ratio.
In T4 Spec Lines, Ford Mustang V6 (05-14), add to Notes the following: "GT 8.8 rear axle assembly allowed. 3.45 or 3.55 final drive ratio allowed. 7.5 rear axle assembly with 3.45:1 final drive allowed."
T4 T4 Mustang
#38058 from Scotty B White · Rule change · TB 25-05 (2025-05 Fastrack)
neutralT4 Ford Mustang V6 05-14 now permits OEM style rear deck spoiler similar to Laguna/CS packages.
In T4 Spec Lines, Ford Mustang V6 (05-14), add to Notes as follows: "OEM style rear deck spoiler similar to Laguna/CS packages permitted.”
STU Table C: STU-GT3U Clarification
#38268 from Club Racing Board · Rule change · TB 25-05 (2025-05 Fastrack)
fasterSTU Spec Line GT3U minimum weight reduced from plus 250 to plus 225 pounds; wheel and tire options clarified with weight adjustments.
In STU Spec Line, Table C: STU-GT3U, change as follows: Minimum Weight: “Current GT3 race weight plus 250 225 pounds” Notes: "DOT approved tire with maximum section width of 245. GT3 cars base wheel is a maximum of 15”x9”. 18”x9” wheels allowd with a 3% weight addition. GT3 cars utilizing 15”x7” wheels are limited to a maximum section width of 225 with a 25 pound weight reduction" "All GT3U (Majors and Runoffs) cars using up to 15"x7" wheels limited to 225 section width tires shall run at current GT3 race weight plus 225lbs. All Gt3U cars shall run a DOT approved tire with a maximum section width of 245. GT3U cars are allowed optional 15"x9" wheels with a 1.5% weight addition or up to 18"x9" wheels with a 3.0% weight addition to the total weight
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including the 225 lbs."
T4 T4 Mustang
#38059 from Scotty B White · Rule change · TB 25-06 (2025-06 Fastrack)
fasterT4 Ford Mustang V6 05-14 weight drops from 3400 to 3300 lbs.
In T4 Spec Lines, Ford Mustang V6 (05-14), change as follows: Final Drive: "3.45 or 3.31" "Weight: "3400 3300"
T4 SSC tire allowance
#38216 from Benjamin Bunk · Rule change · TB 25-06 (2025-06 Fastrack)
neutralT4 Scion FR-S and Subaru BRZ Solo Spec allow any 200TW 225/45/17 or 215/45/17 DOT tire.
In T4 Spec Lines, Scion FR-S Solo Spec Coupe (13-16), change Notes as follows: "Any 200TW 225/45/17 or 215/45/17 DOT tire permitted." In T4 Spec Lines, Subaru BRZ Solo® Spec Coupe (13-16), change Notes as follows: "Any 200TW 225/45/17 or 215/45/17 DOT tire permitted."
Applies to Scion FR-S on this page: Tony Kiratsous
HP Base Weight Adjustment for H-Production X1/9 Spec Lines
#38255 from Matthew Brannon · Rule change · TB 25-06 (2025-06 Fastrack)
fasterHP Fiat X-1/9 base weights reduced 50–53 lbs across 1300 and 1500 spec lines.
In HP Spec Lines, change Weight as follows: Fiat X-1/9 & Bertone1500: “1790 1740 *1835 1784 **1880 1827” Fiat X-1/9 1300: “1650 1600 *1691 1640 **1733 1680” Fiat X-1/9 1300: “2060 2010” Fiat X-1/9 1500: “1950 1900”
STU 2.8-3.2L N/A Engine Allowances
#38007 from Ben Slechta · Rule change · TB 25-07 (2025-07 Fastrack)
unclearSTU 2.8-3.2L N/A engines now allow 245 max tire width; over 3150 lbs may run 275 with 2% weight penalty.
In GCR, Section 9.1.4.G.1, add the following: "A maximum section width of 245 is permitted. Cars over 3150 lbs. may run a 275 tire with a 2% weight adder."
STU 2006-2015 Mazda Miata Intake Manifold
#38422 from German Candelario Candelario · Rule change · TB 25-07 (2025-07 Fastrack)
neutralSTU Mazda MZR may use Goodwin 61-2510 or Gato Performance 31972 intake manifold.
In STU, Table A, Mazda MZR (LF, L3, L5), change Notes as follows: "May use Goodwin Part # 61-2510 or Gato Performance Part #31972 Intake manifold . "
neutralT4 now permits B-Spec and C-Spec cars to compete in the class.
In GCR, Section 9.1.9.2, Touring car eligibility, change as follows: "Touring car eligibility: Cars are eligible for the class they are listed with a specification line and with the specific allowances permitted. In addition T2-T4 cars may race one class up in touring classes above their specification line class as long as they are a legal T2-T4 car and conform to their specification line allowances as classified. Cars conforming to B-Spec or C-Spec rules are permitted to compete in Touring 4."
STU Requesting Approval of the JDM Honda h23a
#38489 from Eric Fiest · Rule change · TB 25-07 (2025-07 Fastrack)
neutralSTU Honda JDM H23a added, 2259cc displacement, minimum weight per Chart, must meet ST engine regulations.
In STU, Table B, classify Honda JDM H23a as follows: STU Maximum Displacement (cc's) Minimum Weight Notes Honda JDM H23a 2259 Chart Must meet all ST engine regulations.
slowerEP BMW Z4 03-05 restricted to 52mm flat plate intake restrictor.
In EP Spec Lines, BMW Z4 (03-05), add to Notes the following: “52mm Flat Plate Intake Restrictor.”
HP EP Fiat 124 Spider Competition Adjustment Request
#38498 from John Baucom · Rule change · TB 25-07 (2025-07 Fastrack)
fasterEP Fiat 124 Spider 1600 & 2000 weight drops 50 lbs to 2000; carburetors gain 2mm chokes to 36mm.
In EP Spec Lines, Fiat 124 Sport Spider 1600 & 124 Spider 2000, change as follows: Weight: "2050 2000" Carburetor No. & Type: "(2) Weber 40 IDF-40IFI, (2) Solex C40P116, 34 36mm choke(s) req’d, (2) Weber 45DCOE w/ 34 36 mm choke(s) on I.R. manifold or fuel injection."
T4 Incorrect Touring Heading
#38451 from Terry Hanushek · Rule change · TB 25-08 (2025-08 Fastrack)
neutralT2, T3, T4 Spec Lines table header changed from T2 to ET.
In T2-T4 Spec Lines, change Table Header as follows: "T2 ET"
STU STU-TCR Adjustments
#38723 from Club Racing Board · Rule change · TB 25-08 (2025-08 Fastrack)
slowerSTU-TCR tire width increases to 275 with weight adder raised from 100 to 150 pounds.
In STU Spec Lines, Table C: STU-GT3U, GT3-TCR, change as follows: Remove the current TCR spec line and add the TCR spec lines from GT3 that are being removed, adding the below to the notes. "DOT approved tire with maximum section width of 245. May run DOT approved tire with maximum section width of 275 with 100 150 pound weight adder. May not run A-compound with 275. STU-TCR spitters and side valance must comply with 9.1.4.D.3.f. STU-TCR chassis ride height must comply with 9.1.4.1.A.1."
STU Lotus Weight Reduction
#38772 from Club Racing Board · Rule change · TB 25-08 (2025-08 Fastrack)
fasterSTL/STU Lotus weight reduced: Evora GT4 to 2700 lbs, Elise Cup R to 2250 lbs, Elise/Exige SC to 2450-2550 lbs.
In 9.1.2. GT2/ST Spec Lines, Lotus Evora GT4, change Weight as follows: "2750 2700" In STU Table B: Alternate Vehicle and Engine Allowances, change Weight as follows: Lotus Elise Cup R: "2300 2250" Lotus Elise SC/ Lotus Exige SC: "2300 2550 2500 2450"
STU Lotus Weight Reduction E&O
#38919 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)
fasterSTU Lotus Elise SC and Exige SC weight reduced from 2450 to 2250 lbs.
In STU Table B: Alternate Vehicle and Engine Allowances, change Weight as follows: Lotus Elise SC/ Lotus Exige SC: "2450 2250"
HP HP Plymouth Arrow spec omission
#38995 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)
neutralHP Plymouth Arrow transmission max speeds clarified to 4 or 5.
In HP Spec Lines, Plymouth Arrow (76-80), add the following wording to Trans. Speeds(max): "4 or 5"
HP Add Wheel Diameter to Appendix G
#39008 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)
neutralEP, FP, HP wheel diameter added to Appendix G as absolute maximum specification.
In Appendix G.2.3, change as follows: "Rim width and diameter are is absolute maximums."
HP Add TB ID tolerance to general Prod rules
#39009 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)
neutralEP, FP, HP throttle body inside dimensions must remain stock with +/-.25mm tolerance; butterfly dimensions stock in FP, HP only.
In GCR, Section 9.1.5.E., change as follows: 9.1.5.E.1.b.4: "The inside dimensions of the throttle body casting/housing (as measured at the throttle butterfly) must remain stock (tolerance of +/-.25mm), but the throttle body can otherwise be ported and polished." 9.1.5.E.2.b.4: "The inside dimensions of the throttle body casting/housing and all dimensions of the throttle butterfly must remain stock (tolerance of +/-.25mm)."
STU Non-Homologated Engine Swaps - Specifically K24A2 w/ Honda CRZ
#38746 from William Rori · Rule change · TB 25-09 (2025-09 Fastrack)
slowerSTU Honda K24 engine swap weight increases by 2% effective November 1, 2025.
In STU Spec Lines, Table B: Alternate Vehicle and Engine Allowances, Honda K24, change Weight as follows: "(Effective 11/1/2025) Chart + 2%"
HP Please Lower Weight of 280Z
#38871 from Matthew Miller · Rule change · TB 25-09 (2025-09 Fastrack)
fasterEP Nissan 280Z minimum weight reduced from 2560 to 2400 lbs.
In EP Spec Lines, Nissan 280Z, change Weight (lbs) as follows: "(Effective 11/1/2025) 2560 2400 *2624 2460 **2688 2520"
HP Miata Weight Adjustment Follow Up
#38949 from Don Tucker · Rule change · TB 25-10 (2025-10 Fastrack)
fasterEP Mazda MX-5 1.8L 90-97 weight reduced to 2125 lbs from 2150 lbs.
In EP Spec Lines, Mazda MX-5 / Miata 1.8L (90-97), Effective 11/1/2025 make the following weight change: "2150 2125"
unclearT4 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.
In T4 Spec Lines, Mini Cooper S R53 (02-06), change Gear Ratios as follows: "12.79, 7.79, 5.65, 4.62, 3.83, 3.13 or overall- 11.42, 7.18, 5.39, 4.40, 3.65, 2.96"
HP Weight Break for 1098 Midget / Sprite
#38970 from Kendall Jones · Rule change · TB 25-10 (2025-10 Fastrack)
In HP Spec Lines, Austin-Healey Sprite/Midget 1098cc, Effective 11/1/2025make the following weight change: "1630 1550"
T4 Reinstatement of the 2005-2010 Cobalt into T4
#38987 from Tim Little · Rule change · TB 25-11 (2025-11 Fastrack)
neutralChevrolet Cobalt SS Sport Coupe 06-10 reinstated to T4 with 2384cc engine, 2628 restrictor, 2700 lbs minimum weight.
In T4 Spec Lines, classify Chevrolet Cobalt SS, Sport Coupe (06-10) as follows:
A specification table follows in the original; it is not shown here.
HP HP Volvo 142 spec omission
#38994 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)
slowerHP Volvo 142/142E gains compression ratio limit 12.0:1 and valve lift limit .425".
In HP Spec Lines, Volvo 142/142E P-1800 Engine, Effective 11/1/2025 add the following wording to Notes: "Comp. Ratio limited to 12.0:1. Valve lift limited to .425”."
HP HP Mini DOHC 1.6
#38996 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)
slowerHP Mini Cooper 07-15 valve lift reduced to .390", from .450".
In HP Spec Lines, Mini Cooper (07-13) (includes 09-15 convertible and 12-15 Coupe), Effective 11/1/2025 make the following changes to the Notes: "Compression ratio limited to 11.0:1, Valve lift limited to .450”.390"."
HP Add to Rabbit description
#39019 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)
neutralFP and HP Volkswagen Rabbit descriptions updated: Convertible changed to Cabriolet in FP; Cabriolet added to three HP engine variants.
In FP Spec Lines, make the following spec line correction: "Volkswagen Rabbit (Includes Convertible Cabriolet)" In HP Spec Lines, make the following spec line correction: "Volkswagen Rabbit 1588 (Includes Cabriolet)" "Volkswagen Rabbit 1715 (Includes Cabriolet)" "Volkswagen Rabbit 1780 (Includes Cabriolet)"
HP Clean-up 9.1.5.E.7e
#39025 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)
neutralEP, FP, HP: rear drum brake to disc conversion clarified; rotors solid, diameter limited to largest front rotor permitted.
In GCR, Section 9.1.5.E.7., change as follows: "e. Cars fitted with rear drum brakes, can convert to rear disc brakes without penalty. Note that the “Brakes Std.” and “Brakes Alt.” listings on a vehicle’s spec line do not prohibit a car that was fitted with rear drum brakes stock, from converting to rear disc brakes under this rule. When converting from rear drum brakes to rear disc brakes: 1. Rear brake rotors must be solid and can be no larger in diameter than the largest permitted front brake rotor, as defined on the vehicle’s spec line. 2. Rear calipers and mounting brackets are unrestricted but must be made of a ferrous or aluminum material. The standard and alternate brake listings on a vehicle’s specification line, does not prohibit a car that was fitted with rear drum brakes as stock
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from converting to rear disc brakes under this rule. 3. The “Brakes Std.” and “Brakes Alt.” listings on a vehicle’s spec line do not prohibit a car that was fitted with rear drum brakes as stock from converting to rear disc brakes under this rule."
T4 Request to Classify Mercedes C230K
#39080 from Patrick Morgan · Rule change · TB 25-11 (2025-11 Fastrack)
neutralMercedes C230 Kompressor 2002-2005 classified in T4 at 3240 lbs with 17-inch wheels and 300/290 mm brakes.
In T4 Spec Lines, classify Mercedes C230 Kompressor (2002-2005) as follows:
A specification table follows in the original; it is not shown here.
HP Add TB size to Ford Mustang (94-98) Spec Line
#39130 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)
neutralEP Ford Mustang (94-98) fuel injected throttle body inside diameter specified at 60.
In EP Spec Lines, Ford Mustang (94-98) add the following to the Fuel Injected Equipped Throttle Body Inside Diameter column: "60"
T4 ND Gearset Request for T4
#39166 from Josh Smith · Rule change · TB 25-11 (2025-11 Fastrack)
neutralT3 and T4 Mazda MX-5 Miata models add approved gear kit PT#-0000-02-6100 to notes.
In T4 Spec Lines, Mazda MX5 Miata/Club/ RF (19-24), add to Notes the following: "Gear kit Kit PT#- 0000-02-6100." In T4 Spec Lines, Mazda MX-5 Miata/Club (16-18), add to Notes the following: "Gear kit Kit PT#- 0000-02-6100." In T3 Spec Lines, Mazda MX-5 Miata (16-18), add to Notes the following: "Gear kit Kit PT#- 0000-02-6100." In T3 Spec Lines, Mazda MX-5 Global Cup Miata (2016-2021) ND1, ND, add to Notes the following: "Gear kit Kit PT#- 0000-02-6100."
Applies to Mazda MX-5 on this page: Oscar Jackson
Applies to Mazda Miata on this page: Kristina Etherington, Kayla Etherington
T4 E&O wheel size on ND
#39168 from Josh Smith · Rule change · TB 25-11 (2025-11 Fastrack)
unclearT4 Mazda MX-5 Miata/Club 16-18 wheel size changed to 17 x 7.5 inches.
In T4 Spec Lines, Mazda MX-5 Miata/Club (16-18), change Wheel Size (in.) as follows: "17 x 7.5"
Applies to Mazda MX-5 on this page: Oscar Jackson
Applies to Mazda Miata on this page: Kristina Etherington, Kayla Etherington
T4 ND Spec Lines Wrong PT#'s
#39170 from Josh Smith · Rule change · TB 25-11 (2025-11 Fastrack)
neutralT4 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.
In T4 Spec Lines, Mazda MX5 Miata/Club/ RF (19-24), change Notes as follows: "Factory bolt-in roll bar/ cross member may be removed to facilitate roll cage installation. The following item(s) must remain stock: transmission differential unless specified below. Retractable hardtop option permitted but must be disabled from moving action and positively fastened. Any OEM or aftermarket hardtop is permitted that retains the OEM roof silhouette, including Mazda hardtop part #0000-07-5902-ND and part #0000-07-5901 (discontinued DG Motorsports). 29mm (f) 16mm (r) sway bars allowed. 3rd and 4th gear may be replaced with the following parts- (0000-02-5803-02, 0000-02-5803-01, 0000-02-5804-02, 0000-02-5804-01). Suspension package permitted with a 100 lbs. weight increase that includes the following parts: front springs #0000-04-9700-08, springs up to 500lb front and 300lb rear allowed. Mazda tower brace 0000-04-5626 allowed. Mazda header
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0000-06-5410 allowed." In T4 Spec Lines, Mazda MX-5 Miata/Club (16-18), change Notes as follows: "Factory bolt-in roll bar/ cross member may be removed to facilitate roll cage installation. Retractable hardtop option permitted but must be disabled from moving action and positively fastened. Any OEM or aftermarket hardtop is permitted that retains the OEM roof silhouette, including Mazda hardtop part #0000-07-5902-ND and part #0000-07-5901 (discontinued DG Motorsports). 29mm (f) 16mm (r) sway bars allowed. Up to 500lb front and 300lb rear springs allowed. Mazda Motorsports Header part #0000-06-5410 allowed. Mazda tower brace 0000-04-5626 allowed. 3rd and 4th gear may be replaced with the following parts- (0000-02-5803-02, 0000-02-5803-01, 0000-02-5804-02, 0000-02-5." In T3 Spec Lines, Mazda MX-5 Miata (16-18), change Notes as follows: "Factory bolt-in roll bar/ cross member may be removed to facilitate roll cage installation. Header permitted. Cold air intake permitted. Front strut brace permitted. Front and rear sway bars permitted up to 35mm, Springs 800 front and 800 Rear max permitted. Any OEM or aftermarket hardtop permitted that retains the OEM roof silhouette including Mazda hardtop part #0000-07-5902- ND and part #0000-07-5901 (discontinued DG Motorsports top). If a hardtop is used, latches shall be replaced with positive fasteners. Retractable hardtop option permitted but must be disabled from moving action and positively fastened. In T3 Spec Lines, Mazda MX-5 Global Cup Miata (2016-2021) ND1, ND, change Notes as follows: "Shoulder harness installation must conform to FIA mounting specifications that are approved for this vehicle per section 6.2 FIA article 253, safety equipment. Must meet all ND2 MX-5 Global Cup rules. Any OEM or aftermarket hardtop is permitted that retains the OEM roof silhouette, including Mazda hardtop Mazda hardtop part #0000-07-5902-ND and #0000-07-5902-ND part #0000- 07-5901 (discontinued DG Motorsports). If a hardtop is used, latches shall be replaced with positive fasteners. OBD2 requirement does not apply. Ballast box may be removed. ND2s with sequential gearbox allowed +100 lbs.
Applies to Mazda MX-5 on this page: Oscar Jackson
Applies to Mazda Miata on this page: Kristina Etherington, Kayla Etherington
T4 Touring 4 Post-Runoffs BOP Adjustments and Changes
In T4 Spec Lines, Acura RSX/ RSX Type-S (02-06), change Restrictor as follows: "55mm FPR" In T4 Spec Lines, Acura TSX (2004-2008), change Restrictor as follows: "47mm FPR 52mm FPR" In T4 Spec Lines, BMW Z4 2.5L (03-05) , change Weight as follows: "3050 2950" In T4 Spec, BMW 320i (14-15), remove this spec line in its entirety. In T4 Spec Lines, BMW 323 (98-00), change as follows:
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Tire size: "225 245" Weight: "3250 3150" In T4 Spec Lines, Ford Mustang V6 (05-14), change as follows: Restrictor: "50mm 43mm" Weight: "3300 3400" In T4 Spec Lines, Honda Civic Si (06-11), change Restrictor as follows: "55mm" In T4 Spec Lines, Honda Civic Si (12-15), change as follows: Restrictor: "47mm 52mm Notes: "Transmission and Differential must be stock." In T4 Spec Lines, Mazda MX-5 / Club Model (06-15), change as follows: Weight: "2550 2500" Notes: "Factory bolt-in roll bar/cross member may be removed to facilitate roll cage installation. MSR option permitted. Suspension package permitted with a 100 lbs. weight increase that includes the following parts: front spring mount PT#-0000- 04-5259, front springs #0000-04-9700-08, rear spring mount PT#-0000-04-5258, rear springs #0000- 04-9400-07, helper springs #0000-04-HLPR-EB (optional), Swaybar kit – PT#-0000-04-5306-EB that includes (front sway bar kit PT#0000-04-5306-FT, rear sway bar kit PT#-0000-04-5306-RR), offset front camber bushing PT#- 0000-04-5407-NC. Mazda Motorsports cold air intake part #0000-06-5150-KT allowed. Mazda Motorsport RX8 rear Hub Conversion kit part number 0000-04-5811-KT allowed, RX8 front hubs PT# F189-33-04X allowed. Allow Mazda header part numbers 0000-06-5407 or 0000-06-5407-NC. Any OEM or aftermarket hardtop is permitted that retains the OEM roof silhouette, including Mazda hardtop and part #0000-07-5901-CC. Aftermarket power steering reservoir is allowed. Mazda Transmission kit part # 0000-02-5700. Mazda Motorsports LSD #32655 permitted without penalty. Any other non-OEM limited slip differential allowed with +50 lbs. weight penalty. Front spoiler permitted (NF51-V4-900F). Transmission kit # 0000-02-57 In T4 Spec Lines, Pontiac Solstice / Saturn Sky (06-09), change as follows: Weight: "2800 2700" Brakes: "(F) 296 315 Vented Disc max (R) 278 Solid Disc" Notes: "GM calipers #22720705, and #25900764 permitted" In T4 Spec Lines, Scion FRS/10 series (13-16), change Weight as follows: "2925 2875" In T4 Spec Lines, Subaru BRZ/ BRZ Limited (13-16), change Weight as follows: "2925 2875" In T4 Spec Lines, Subaru BRZ (17-21), change Weight as follows: "3000 2950" In T4 Spec Lines, Toyota 86, GT (17-21), change Weight as follows: "3000 2950" SCCA Runoffs
Applies to Mazda MX-5 on this page: Oscar Jackson
STU Turbo Inlet Restrictor Table
#38961 from John Weisberg · Rule change · TB 25-12 (2025-12 Fastrack)
slowerSTU 36mm restrictor allows 2830 lbs (up 10 lbs from 2820); 37mm allows 2980 lbs (down 5 lbs from 2985).
In GCR, Section 9.1.4.H.3, change chart as follows:
A specification table follows in the original; it is not shown here.
STU 275 Tire Rule
#38983 from Peter Federlin · Rule change · TB 25-12 (2025-12 Fastrack)
slowerSTU cars over 3150 lbs lose 275-tire option with 2% weight adder.
In GCR, Section 9.1.4.G.1., change as follows: "A maximum section width of 245 is permitted. Cars over 3150 lbs. may run a 275 tire with a 2% weight adder."
HP Request to Re-Classsify Datsun SPL-311 to HP from FP
#39116 from Robert Heatwole · Rule change · TB 25-12 (2025-12 Fastrack)
neutralDatsun SPL-311 newly classified to HP at 2050 lbs with 1595cc OHV iron engine and specified carburetors.
In HP Spec Lines, classify Nissan/Datsun SPL 311 as follows:
A specification table follows in the original; it is not shown here.
HP TR2 Notes E&O
#39180 from Anthony Parker · Rule change · TB 25-12 (2025-12 Fastrack)
unclearEP Triumph TR2-TR4A allows 5-speed gearbox without overdrive; removes Weber carb and weight specification.
In EP Spec Lines, Triumph TR2, 3, 3A, 4, 4A, TR4, TR4A, IRS, make the following change to the Notes: "Front apron assembly may be made of alternate material. Three (3) Weber 40 DCOE on IR manifold with 28mm chokes @ 1990 lbs. Laycock overdrive, may use 5 speed gearbox without overdrive."
HP Balance of Power
#39187 from Jim Simaras · Rule change · TB 25-12 (2025-12 Fastrack)
slowerEP BMW Z3 2.5L restrictor reduced 52mm to 50mm, weight increased to 2550 lbs base; five other BMW models get smaller restrictors.
In EP Spec Lines, make the following changes to Restrictors: BMW Z3 2.5L: "52mm 50mm Flat Plate Intake Restrictor" BMW Z3 2.8L (97-00): "55mm 53mm Flat Plate Intake Restrictor" BMW 328i/is E36 (96-99): "58mm 55mm Flat Plate Intake Restrictor" BMW 328i/ci E46 (01-06): "58mm 55mm Flat Plate Intake Restrictor" BMW 325i/is (E46) (01-06): "56mm 53mm Flat Plate Intake Restrictor" BMW 325is M-Technic (1994): "56mm 53mm Flat Plate Intake Restrictor" BMW 325i/is E-36 (92-95): "56mm 53mm Flat Plate Intake Restrictor"
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In EP Spec Lines, BMW Z3 2.5L, change Weight as follows: "2500 2550 *2563 2614 **2625 2678"
HP Alternative BOP Request for 84-87 Honda CRX/Civic
#39223 from Bill Lamkin · Rule change · TB 25-12 (2025-12 Fastrack)
fasterHP Honda Civic and CRX models get wider 13-inch wheels: 6 to 7 inches.
In HP Spec Lines, change Wheels as follows: Honda Civic: "13 x 6 7" Honda Civic DX (92-95): "13 x 6 7" Honda Civic/Si (84-87): "13 x 6 7" Honda Civic 1.5 (88-91): "13 x 6 7" Honda CRX/Si (84-87): "13 x 6 7" Honda CRX 1.5(88-91): "13 x 67"
neutralT2, T3, T4 cars may relocate under-dash electronics and fuse boxes for access after roll cage installation.
In GCR, Section 9.1.9.2.D.9.d, add the following: "8. Under-dash electronics including computers, modules and fuse boxes may be relocated so they can be easily accessed after roll cage installation."
HP E/O: Improve Consistency of the Spec Lines
#39500 from Robert Bax · Rule change · TB 26-01 (2026-01 Fastrack)
unclearHP Toyota MR-2 1.6L (85-89) compression ratio set to 11.0:1.
In HP Spec Line, Toyota MR-2 1.6L (85-89), change Comp. Ratio as follows: "11.0:1"
T4 Clarify T4 Brake Rotor Allowance
#39503 from David Mead · Rule change · TB 26-01 (2026-01 Fastrack)
neutralT4 Performance now permits 1-piece alternative rotors matching spec line sizes; alternate brake kits allowed same.
In GCR, Section 9.1.9.2.D.6.a.6., change as follows: "In T2-Performance alternative rotors, including 2 piece rotors are permitted. Rotors must be within 5% of OE diameter or a maximum diameter of 360mm. In T3- Performance alternative rotors, including 2 piece rotors are permitted with a maximum diameter of 360mm. T4- Performance alternative 1-piece rotors are permitted but rotors must meet the sizes listed in the spec line. Spec lines showing alternate brake kits are also permitted to use 1-piece performance alternative rotors of the same size."
STU Request for Permission on Aftermarket Turbo Kit and Intake
#39529 from John Grim · Rule change · TB 26-01 (2026-01 Fastrack)
fasterSTU Mazda MZR (LF, L3, L5) Turbo classified; Jack Spania Racing 70 mm intake manifold and Fab9 Tuning bottom-mount turbo kit approved.
In STU Spec Lines, Table A: Alternate Vehicle and Engine Allowances, Mazda MZR (LF, L3, L5), change Notes as follows: "Short blocks, heads, and intakes may be freely swapped within these engine designations. May use Goodwin Part # 61- 2510 or, Gato Performance Part #31972 or Jack Spania Racing 70 mm sheet-metal aluminum Intake manifold. Must use stock throttle body or Acura part number 16400-PND-A17." In STU Spec Lines, Table A: Alternate Vehicle and Engine Allowances, classify Mazda MZR (LF, L3, L5) Turbo as follows: STU Maximum Displacement (cc's) Minimum Weight Notes Mazda MZR (LF, L3, L5) Turbo
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Varies Chart Short blocks, heads, and intakes may be freely swapped within these engine designations. May use Jack Spania Racing 70 mm sheet-metal aluminum Intake manifold. Must use stock throttle body or Acura part number 16400-PND- A17. Fab9 Tuning bottom-mount turbo kit approved with one of the STU approved Turbos.
HP Request to Reclassify BMW 2002 Into H Production
#39567 from Jonathan Kinberg · Rule change · TB 26-01 (2026-01 Fastrack)
neutralBMW 2002 newly classified to H Production at 2350 lbs with 1990cc iron block, 40 DCNF carburetor, 11.0:1 compression.
In HP Spec Lines, classify BMW 2002, as follows:
A specification table follows in the original; it is not shown here.
T4 T4 and T3 Feedback
#39230 from Tim Myers · Rule change · TB 26-02 (2026-02 Fastrack)
neutralFord Mustang V6 (05-14) removed from T4 Spec Lines.
In T4 Spec Lines, remove Ford Mustang V6 (05-14) in its entirety.
T4 T4 Mustang 4.0
#39489 from Scotty B White · Rule change · TB 26-02 (2026-02 Fastrack)
fasterT4 Mustang 4.0 V6 tire size increases from 245 to 255.
In T4 Spec Lines, Ford Mustang V6 (05-10), change as follows: Tire: "245 255" Notes: "ABS (option code 552) allowed. FR3 Handling Pack #M-2007-FR3V6 allowed (kit does not need to be run in its entirety). The kit includes: Dampers M-18000-A, Lowering Springs M-5300-N, Sway Bars M- 5490-C, Strut Tower Brace M-20201-F. Ford Positraction LSD part #M-4204-C75 is allowed. Any springs max F: 500 and R: 400 permitted. Any sway bar up to F: 35mm and R: 28mm permitted. Aftermarket Shocks conforming to T4 rules allowed. Panhard bar, part # BAR-M-4264-A permitted, or any pan hard bar permitted must be set at same length as a stock bar, center mounting hole to center mounting hole +/- 0.25 inch. An alternative steel drive shaft is permitted; this drive shaft is otherwise unrestricted, but no modifications to other components
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are permitted to facilitate its installation. An Aluminum driveshaft is allowed. Any LSD permitted. Ford brake kit M-2300-D allowed. Aftermarket header allowed. GT 8.8 rear axle assembly allowed. 3.45 or 3.55 Alternate final drive ratio allowed. 7.5 rear axle assembly with 3.45:1 final drive allowed. Cold Air Intake allowed. Koni part numbers 8741-1494SPORT (front) and 8241-1240SPORT (rear). Spec clutch #SF661 and flywheel #SF66A permitted. 14” Brembo Brake Kit#M-2300-S permitted."
HP Triumph Spitfire 1296cc Compression Ratio Increase to 12:1
#39589 from Neil Verity · Rule change · TB 26-02 (2026-02 Fastrack)
fasterHP Triumph Spitfire 1296cc compression ratio increases from 11.0 to 12.0:1.
In HP Spec Lines, make the following spec line changes: Triumph Spitfire: Carburetion "Valves: (I) 33.0/(1.30) (E) 29.7/(1.17) Comp. ratio 11.0 12.0:1, Valve lift .450” Trans. Speeds: 4" Triumph Spitfire Mk. III & IV 1500: Carburetion
#39607 from David Mead · Rule change · TB 26-02 (2026-02 Fastrack)
fasterT2-T4 adjustable toe links now allow performance alternative bushings and spherical bearings, previously prohibited except in specified examples.
In GCR, Section 9.1.9.D.5.a.1., change as follows: "T2-T4: A maximum of 3.5 degrees of negative camber is allowed on front and rear suspensions. Spec line part(s) may not be modified to increase caster and camber. Strut suspensions may adjust camber and caster by the use of eccentric bushings, eccentric bolts (crash bolts) at the strut-to-spindle, and/or by use of slotted adjustment plates at the top of the strut mounting plate. If upper strut slotted adjustment plates are used, they shall be located on existing chassis structure, utilizing the unmodified manufacturer’s original bolt holes and may not serve as reinforcement for that structure. Slotted adjustment plates (strut camber plates) may incorporate a single spherical bearing (spherical bushing) and a ball thrust bearing per strut tower. On other forms of suspension, camber and caster adjustment may be achieved by the use of shims and/or eccentric
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bushings. Adjustable toe links with spherical bearings are permitted and may serve no purpose other than adjusting toe angle. Adjustable toe links are permitted. They are allowed to have performance alternative bushings and spherical bearings. They may serve no purpose other than adjusting toe angle. Spherical bearings/bushings are not permitted in T2-T4 except for the specific examples listed in the class rules or vehicle spec line."
What the rules allowed changed as listed; this does not say what any particular car ran.