P + T4 + STU at Buttonwillow Raceway Park

2023-03-01 STU E&O STU NA Weight Chart.

#33737 from Eric Heinrich · Rule change · TB 23-03 (2023-03 Fastrack)

In STU, GCR Section 9.1.4.1.H.1. chart, Factory Engine Displacement (cc) Minimum Weight (lbs), change as follows:
"2450 2596 2595"
"2600 2860 2710"

2023-03-01 T4 BMW 320I intercooler

#33762 from Chi Ho · Rule change · TB 23-03 (2023-03 Fastrack)

In T3 Spec Lines, BMW- 320I, add to Notes the following:
"Aftermarket intercooler permitted."

2023-04-01 T4 Request to Classify 2004-2008 Acura TSX in T4

#33590 from William Phee · Rule change · TB 23-04 (2023-04 Fastrack)

In T4 Spec lines, classify Acura TSX (2004-2008) as follows:

A specification table follows in the original; it is not shown here.

2023-04-01 STU Alternate OEM Miata Intake Manifold

#33827 from Brandon Steinhauer · Rule change · TB 23-04 (2023-04 Fastrack)

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.

2023-04-01 T4 T4 Mustang Brakes/Swaybar

#34036 from Scotty B White · Rule change · TB 23-04 (2023-04 Fastrack)

In T4 Spec Lines, Ford Mustang (2005-2010), change Notes as follows:
"Any sway bar up to F: 35mm and R: 22mm 28mm permitted."

2023-06-01 T4 05-06 Mini Wheel Weight

#34112 from Mav Singh · Rule change · TB 23-06 (2023-05 Fastrack)

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"

2023-06-01 T4 06-09 VW Rabbit

#34153 from Cameron Conover · Rule change · TB 23-06 (2023-05 Fastrack)

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."

2023-06-01 T4 96-01 Audi a4 2.8 Spring Rate

#34217 from Michael Gordhamer · Rule change · TB 23-06 (2023-05 Fastrack)

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."

2023-07-01 T4 2002-2006 Mini Cooper S R53 Spec Line Request

#34336 from Aaron Fitzsimmons · Rule change · TB 23-06 (2023-07 Fastrack)

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"

2023-07-01 STU 2022 Toyota GR Cup for STU

#34449 from Club Racing Board · Rule change · TB 23-06 (2023-05 Fastrack)

In STU Spec Lines, Toyota GR Cup (2022-), classify as follows:

A specification table follows in the original; it is not shown here.

2023-08-01 T4 Rules Clarification for Mazda RX8 Spec Line

#34395 from Colin Koehler · Rule change · TB 23-08 (2023-08 Fastrack)

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:

2023-08-01 T4 rule book corrections

#34437 from Chi Ho · Rule change · TB 23-08 (2023-08 Fastrack)

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."

2023-08-01 T4 Ride Height Correction for the T3 Solstice.

#34615 from Joe Aquilante · Rule change · TB 23-08 (2023-08 Fastrack)

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."

2023-09-01 T4 Inclusion of similar car. (CLK 320)

#34626 from Patrick Morgan · Rule change · TB 23-09 (2023-09 Fastrack)

In T4 Spec Lines, Mercedes Benz CLK 320 Coupe (2004), change as follows:
"Mercedes Benz CLK 320 Coupe, C320 Sedan (2004 2000-2007)

2024-01-01 T4 Mazda MX-5 ND1 Spec Line Request

#34232 from Josh Smith · Rule change · TB 24-01 (2024-01 Fastrack)

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

2024-01-01 T4 BRZ/FRS/86 Spring Allowance

#35038 from Luis Goncalves · Rule change · TB 24-01 (2024-01 Fastrack)

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

2024-01-01 T4 TSX Allowance

#35219 from Oscar Jackson · Rule change · TB 24-01 (2024-01 Fastrack)

In T4 Spec Lines, Acura TSX (2004-2008), add to Notes the following:
"Header allowed."

2024-01-01 T4 Requested Update of Model Years of 370Z

#35231 from Richard Kulach · Rule change · TB 24-01 (2024-01 Fastrack)

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)"

2024-02-01 STU ST Electric-Assisted Steering Systems

#35066 from Jose Osiris Pena · Rule change · TB 24-02 (2024-01 Fastrack)

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"

2024-02-01 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."

2024-02-01 T4 ND Missed Items

#35352 from Touring Committee · Rule change · TB 24-02 (2024-02 Fastrack)

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

2024-02-01 T4 Inclusion of B-C spec cars in T4

#35374 from Touring Committee · Rule change · TB 24-02 (2024-02 Fastrack)

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."

2024-02-01 T4 T2-T4 Set expiration dates on spec lines

#35378 from Touring Committee · Rule change · TB 24-02 (2024-02 Fastrack)

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)

2024-03-01 T4 Reorganize Spec Lines

#35375 from Touring Committee · Rule change · TB 24-03 (2024-03 Fastrack)

In T2-T4 Spec Lines, change Spec Line as follows:
"Wheel- base (mm) Required Restrictor"

2024-03-01 T4 Allow any 400lb rear spring in the RX8

#35433 from Raymond Blethen · Rule change · TB 24-03 (2024-03 Fastrack)

In T4 Spec Lines, Mazda RX-8 Base/R3/Sport/ GT (04-12), change Notes as follows:
"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. Springs allowed 700lb (f), 400(r)."

2024-03-01 STU Letter #35397 addendum

#35453 from Aaron Fitzsimmons · Rule change · TB 24-03 (2024-03 Fastrack)

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."

2024-03-01 STU S54 Drysump

#35464 from Macey Urso · Rule change · TB 24-03 (2024-03 Fastrack)

In STU Spec Lines, BMW S54 B32 OEM, add to Notes as follows:
"Dry Sump oiling system permitted."

2024-03-01 T4 370Z Brake Rotor Size Correction

#35487 from Derek Chan · Rule change · TB 24-03 (2024-03 Fastrack)

In T2 Spec Lines, Nissan 370Z (09-17) / 370Z NISMO Edition (09-17), change Brakes (mm) as follows:
"(F)320 x 28 Vented R)320 x 16 Vented : (F) 355x32mm Vented(R) 350x20mm Vented”
In T3 Spec Lines, Nissan 370Z, incl. Nismo (2009-2022), change Brakes (mm) as follows:
"(F)320 x 28 Vented (R)320 x 16 Vented : (F) 355x32mm Vented(R) 350x20mm Vented”

2024-04-01 T4 Corrections to T4 RX8 Spec line

#35767 from Touring Committee · Rule change · TB 24-04 (2024-04 Fastrack)

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)."

2024-05-01 T4 Allow T4 and T3 RX8 to Disable/Remove Factory Oil Inj.

#35761 from David Mead · Rule change · TB 24-05 (2024-05 Fastrack)

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."

2024-05-01 T4 2023 ND2 Miata Classification and Allowances

#35837 from Coyote Black · Rule change · TB 24-05 (2024-05 Fastrack)

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."

2024-05-01 T4 Errors and Omissions for 06-09 VW Rabbit Rotor

#35851 from Andrew Burke · Rule change · TB 24-05 (2024-05 Fastrack)

In T4 Spec Lines, Volkswagen Rabbit 2.5 (06-09), change Brakes as follows:
"(F) 228 288 Vented Disc (R) 260 Solid Disc"

2024-05-01 T4 Driveshafts

#35916 from Scotty B White · Rule change · TB 24-05 (2024-05 Fastrack)

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."

2024-05-01 T4 GCR ERROR - letter not properly applied to GCR

#35999 from Touring Committee · Rule change · TB 24-05 (2024-05 Fastrack)

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

2024-06-01 T4 Allow OEM Front Spoiler 06-08 Miata in T4

#35941 from David Mead · Rule change · TB 24-06 (2024-06 Fastrack)

In T4 Spec Lines, Mazda MX-5 / Club Model (06-15), add to Notes the following: "Front
spoiler permitted (NF51-V4-900F)."

Applies to Mazda MX-5 on this page: Oscar Jackson

2024-06-01 T4 T4 Mustang Weight Reduction In T4 Spec

#36051 from Scotty B White · Rule change · TB 24-06 (2024-06 Fastrack)

Lines, Ford Mustang V6 (05-10), change as follows:
Weight: "3275 3225"
Notes: "14” Brembo Brake Kit#M-2300-S permitted."

2024-06-01 T4 R53 Mini Cooper S spec line request In

#36056 from Manvinder Singh · Rule change · TB 24-06 (2024-06 Fastrack)

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."

2024-07-01 T4 Mustang T2/T3

#35877 from Scotty B White · Rule change · TB 24-07 (2024-07 Fastrack)

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."

2024-07-01 T4 Homologation of car to T4

#36030 from Patrick E Morgan · Rule change · TB 24-07 (2024-07 Fastrack)

In T4 Spec Lines, Mercedes C300 4Matic (2008-2011), classify as follows:

A specification table follows in the original; it is not shown here.

2024-07-01 T4 T2-T4 Driveshaft Mistake...?

#36050 from Scotty B White · Rule change · TB 24-07 (2024-07 Fastrack)

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."

2024-07-01 T4 MINI Cooper S Spec Lines Corrections.

#36086 from David Oliveira · Rule change · TB 24-07 (2024-07 Fastrack)

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

2024-07-01 T4 Allow Removal of Sound Tubes

#36130 from Coyote Black · Rule change · TB 24-07 (2024-07 Fastrack)

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."

2024-07-01 T4 B8/8.5 Audi S4 T3 and T2

#36195 from Brian Leib · Rule change · TB 24-07 (2024-07 Fastrack)

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.

2024-08-01 T4 T4 Camaro V6 weight reduction

#36232 from Ted Warning · Rule change · TB 24-08 (2024-08 Fastrack)

In T4 Spec Lines, Chevrolet Camaro V-6 (96-02), change weight as follows:
"3250 3150"

2024-08-01 STU RWD Turbo Disadvantage

#36255 from David Fiorelli · Rule change · TB 24-08 (2024-08 Fastrack)

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"

2024-08-01 T4 BOP adjustment for ND MX5s

#36345 from Touring Committee · Rule change · TB 24-08 (2024-08 Fastrack)

In T4 Spec Lines, change Weight (lbs) as follows:
Mazda MX-5 Miata/Club (16-18): "2700 2650"
Mazda MX5 Miata/Club/ RF (19-24): "2800 2750"

2024-11-01 STU R53 15% Pulley Request

#36980 from Aaron Fitzsimmons · Rule change · TB 24-11 (2024-11 Fastrack)

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."

2024-11-01 T4 Bop Request 06-11 Honda Civic Si

#37013 from Mathew Milford · Rule change · TB 24-11 (2024-11 Fastrack)

In T4 Spec Lines, Honda Civic Si (06-11), add to Notes the following:
"LSD is permitted according to category rules."

2024-12-01 T4 Redundant Verbiage Regarding Mustang Spec Lines for Driveshaft

#36484 from David Mead · Rule change · TB 24-12 (2024-12 Fastrack)

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."

2024-12-01 T4 R53 Mini Cooper S Weight Reduction Request

#36612 from Manvinder Singh · Rule change · TB 24-12 (2024-12 Fastrack)

In T4 Spec Lines, Mini Cooper S R53 (02-06), add to Notes as follows:
"Alta 15% Pulley #AMPENG20X allowed."

2024-12-01 T4 Allowable Wheel Offset

#36855 from Robert Maples · Rule change · TB 24-12 (2024-12 Fastrack)

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

2024-12-01 T4 Fuel Emissions Components

#37076 from Derrick Ambrose · Rule change · TB 24-12 (2024-12 Fastrack)

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."

2024-12-01 T4 2019-2024 Mazda 3 for T4

#37077 from Derrick Ambrose · Rule change · TB 24-12 (2024-12 Fastrack)

In T4 Spec Lines, classify Mazda 3 (19-24), as follows:

A specification table follows in the original; it is not shown here.

2024-12-01 T4 fix brake wording

#37129 from Touring Committee · Rule change · TB 24-12 (2024-12 Fastrack)

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

2024-12-01 T4 Evaporative emissions systems

#37130 from Touring Committee · Rule change · TB 24-12 (2024-12 Fastrack)

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."

2024-12-01 STU Request to Remove Miata Hubs from General category

#37138 from Christopher Childs · Rule change · TB 24-12 (2024-12 Fastrack)

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."

2024-12-01 T4 Allow Spec MX5 upgrade kit for 2009-11 RX8 S2 Transmision

#37140 from Chris Braunlich · Rule change · TB 24-12 (2024-12 Fastrack)

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."

2024-12-01 STU BMW N54/N55 Engine Allowance

#37146 from Martin Sarukhanyan · Rule change · TB 24-12 (2024-12 Fastrack)

"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.

2024-12-01 T4 Move Spec Boxster to T4

#37158 from Rob Piekarczyk · Rule change · TB 24-12 (2024-12 Fastrack)

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

2024-12-01 T4 3.7 Mustangs to T4

#37188 from Scotty B White · Rule change · TB 24-12 (2024-12 Fastrack)

In T4 Spec Lines, classify Ford Mustang V6 (05-14), as follows:

A specification table follows in the original; it is not shown here.

2024-12-01 T4 BMW 320i Spec Line

#37204 from chi ho · Rule change · TB 24-12 (2024-12 Fastrack)

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."

2024-12-01 T4 MX5 2006-2015 NC Help

#37221 from Richard Mooney · Rule change · TB 24-12 (2024-12 Fastrack)

Thank you for your letter. Please see changes in letter #37281 in current Fastrack.

2024-12-01 T4 Classification for a 2005 Cadillac CTS 3.6 liter 6 speed manual

#37224 from Timothy Nash · Rule change · TB 24-12 (2024-12 Fastrack)

In T3 Spec Lines, classify Cadillac CTS (02-07) as follows:

2024-12-01 T4 Civic SI in T4

#37248 from Touring Committee · Rule change · TB 24-12 (2024-12 Fastrack)

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"

2024-12-01 T4 2006-2015 T4 NC Mx5 spec line

#37278 from Touring Committee · Rule change · TB 24-12 (2024-12 Fastrack)

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-

Applies to Mazda MX-5 on this page: Oscar Jackson

2024-12-01 T4 ND MX-5 wheel allowance

#37279 from Josh Smith · Rule change · TB 24-12 (2024-12 Fastrack)

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

2024-12-01 T4 T4 BOP

#37281 from Touring Committee · Rule change · TB 24-12 (2024-12 Fastrack)

In T4 Spec Lines, Mazda RX-8 Base/R3/Sport/ GT (04-12), change as follows:
Required Restrictor: "60mm 59mm"
Weight: "3125 3200"
In T4 Spec Lines, Mazda MX-5 / Club Model (06-15), change weight as follows:
"2600 2550"

Applies to Mazda MX-5 on this page: Oscar Jackson

2024-12-01 T4 Allow 7.5

#37286 from Touring Committee · Rule change · TB 24-12 (2024-12 Fastrack)

In T4 Spec Lines, Mazda MX5 Miata/Club/ RF (19-24), change Wheel Size as follows:
"17 x 7.5"

2025-01-01 STU Audi 1.8t Wagon STU Table B

#36685 from Mike McLaughlin · Rule change · TB 25-01 (2025-01 Fastrack)

In STU Spec Lines, Table B: Alternate Vehicle and Engine Requirements, delete Audi/VW 1.8 Turbo in its entirety.
In STU Spec Lines, Table B: Alternate Vehicle and Engine Requirements, Porsche 944 w/Max Displacement 1800, change as
follows:
Weight: "3050 Chart"
Notes: "VW/Audi 1.8L 35mm turbo engine permittedinlet restrictor required."

2025-01-01 T4 2016-2018 Mazda Miata MX5

#37085 from Nic Piekarski · Rule change · TB 25-01 (2025-01 Fastrack)

In T4 Spec Lines, Mazda MX-5 Miata/Club (16-18), change Min Weight as follows:
"2650 2575"
In T4 Spec Lines, Mazda MX5 Miata/Club/ RF (19-24), add to Notes the following:
"Mazda header 0000-06-5410 allowed."

Applies to Mazda MX-5 on this page: Oscar Jackson

Applies to Mazda Miata on this page: Kristina Etherington, Kayla Etherington

2025-01-01 T4 Remove spec lines that have expired

#37269 from Touring Committee · Rule change · TB 24-12 (2024-12 Fastrack)

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)

2025-01-01 STU Merger GT3 to STU

#37486 from Club Racing Board · Rule change · TB 25-01 (2025-01 Fastrack)

In STU, Table C, change STU-GT3 charge as follows:
"(Effective January 1, 2026) TABLE C: STU-GT3U"

2025-01-01 STU GT3 TCR Tire allowance

#37494 from Club Racing Board · Rule change · TB 25-01 (2025-01 Fastrack)

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."

2025-02-01 T4 Ford Mustang V6 (05-14)

#37516 from Touring Committee · Rule change · TB 25-02 (2025-02 Fastrack)

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."

2025-02-01 T4 Request to Classify Club Spec in Appropriate Touring Classes

#37523 from Andrew Benagh · Rule change · TB 25-02 (2025-02 Fastrack)

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.

Applies to Mazda MX-5 on this page: Oscar Jackson

2025-02-01 P Correct text in engine table notes

#37606 from Club Racing Board · Rule change · TB 25-02 (2025-02 Fastrack)

In Prototype Engine Table, Spec Line B, change the notes as follows:
"Staudacher cars may run 950 lb min. wt. minimum weight with 38.5mm flat plate intake restrictor."
In Prototype Engine Table, Spec Line D, change the notes as follows:
"No restrictor required at 1150 lb min. wt. minimum weight."

2025-02-01 P Update Prototype class designation

#37653 from Club Racing Board · Rule change · TB 25-02 (2025-02 Fastrack)

In Categories and Classes, GCR section 9.1, change as follows:
"9.1.8. SPORTS RACING CATEGORY CLASSES
A Sports Racing (ASR) Regional Class
Prototype 1 (P1)"
In Homologation Requirements, GCR section 9.2.2, change as follows:
"All Formula, Sports Racing, and P1, and P2 cars must be constructed in strict accordance with the rules and regulations
contained in the current GCR unless specifically excepted."
In Non-Metallic Wheel/Chassis Construction, GCR section 9.3.37, change as follows:

2025-03-01 STU BMW N54/N55 Engine Allowance Follow Up

#37447 from Martin Sarukhanyan · Rule change · TB 25-03 (2025-03 Fastrack)

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

2025-03-01 STU STU Mini Cooper pulley size clarification re: letter #36980

#37717 from Aaron Fitzsimmons · Rule change · TB 25-03 (2025-03 Fastrack)

In STU Spec Lines, Mini Cooper S SC, add to notes:
2100: "May run a 2.285 2.185 diameter pulley."

2025-03-01 STU Question About a Weight Modifier

#37782 from Peter St Pierre · Rule change · TB 25-03 (2025-03 Fastrack)

In STU Spec Lines, Table A, Honda K20C1 Turbo I4, add to Notes the following:
"The 3% DI weight adder does not need to be applied."

2025-03-01 STU Increase Minimum Weight

#37919 from Club Racing Board · Rule change · TB 25-03 (2025-03 Fastrack)

In STU Spec Lines, Table C: STU-GT3U, change Minimum Weight as follows:
"150 250 pounds"

2025-05-01 STU Wheel Size Inconsistency

#38018 from David Fiorelli · Rule change · TB 25-05 (2025-05 Fastrack)

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."

2025-05-01 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)

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."

2025-05-01 T4 T4 Mustang

#38058 from Scotty B White · Rule change · TB 25-05 (2025-05 Fastrack)

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.”

2025-05-01 P Add missing punctuation marks

#38150 from Club Racing Board · Rule change · TB 25-05 (2025-05 Fastrack)

In P Engine Table, Spec Line D notes, add the following:
"No restrictor required at 1150 lbs. minimum weight."
In P Engine Table, Spec Line G notes, add the following:
"Group CN non-composite chassis with Honda K20A-FD2 may use unrestricted individual throttle bodies at 1500 lbs. minimum
weight."
In P Table 1, Beasley B2 spec line notes, add the following:
"Engine must be Mazda 12A rotary with 40.5mm venturi. Car must comply with all other Prototype requirements."
In P Table 1, P2 cars built to 2000cc auto-based specification spec line notes, add the following:

2025-05-01 STU Table C: STU-GT3U Clarification

#38268 from Club Racing Board · Rule change · TB 25-05 (2025-05 Fastrack)

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

2025-06-01 T4 T4 Mustang

#38059 from Scotty B White · Rule change · TB 25-06 (2025-06 Fastrack)

In T4 Spec Lines, Ford Mustang V6 (05-14), change as follows:
Final Drive: "3.45 or 3.31"
"Weight: "3400 3300"

2025-06-01 T4 SSC tire allowance

#38216 from Benjamin Bunk · Rule change · TB 25-06 (2025-06 Fastrack)

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

2025-07-01 STU 2.8-3.2L N/A Engine Allowances

#38007 from Ben Slechta · Rule change · TB 25-07 (2025-07 Fastrack)

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."

2025-07-01 STU 2006-2015 Mazda Miata Intake Manifold

#38422 from German Candelario Candelario · Rule change · TB 25-07 (2025-07 Fastrack)

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 . "

2025-07-01 T4 Allow B-Spec cars to run in T4

#38439 from Derrick Ambrose · Rule change · TB 25-07 (2025-07 Fastrack)

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."

2025-07-01 STU Requesting Approval of the JDM Honda h23a

#38489 from Eric Fiest · Rule change · TB 25-07 (2025-07 Fastrack)

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.

2025-08-01 T4 Incorrect Touring Heading

#38451 from Terry Hanushek · Rule change · TB 25-08 (2025-08 Fastrack)

In T2-T4 Spec Lines, change Table Header as follows:
"T2 ET"

2025-08-01 STU STU-TCR Adjustments

#38723 from Club Racing Board · Rule change · TB 25-08 (2025-08 Fastrack)

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."

2025-08-01 STU Lotus Weight Reduction

#38772 from Club Racing Board · Rule change · TB 25-08 (2025-08 Fastrack)

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"

2025-08-01 P RM 25-05 - Prototype Engine Table A, 2 Cycle Restrictor Change

#38929 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)

Effective 8/1/25 in Prototype Engine Table, Spec Line A, change the restrictor as follows:
"40mm 38mm Restricted Venturi Size"

2025-09-01 P 13B Rotary Engine Rules Change Request

#38856 from Jason Vinkemulder · Rule change · TB 25-09 (2025-09 Fastrack)

Effective 9/1/25 in Prototype Engine Table, Spec Line K, change the restrictor as follows:
"40mm SIR with fuel injection or 41.5mm venturi with carburetor"

2025-09-01 P Add Radical Cup series Radical SR3 spec line to Table 1

#38916 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)

Effective 9/1/25 in Prototype Table 1 (Spec Line Cars), add the following:

2025-09-01 STU Lotus Weight Reduction E&O

#38919 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)

In STU Table B: Alternate Vehicle and Engine Allowances, change Weight as follows:
Lotus Elise SC/ Lotus Exige SC: "2450 2250"

2025-09-01 P Clarify spec line cars language

#38943 from Club Racing Board · Rule change · TB 25-09 (2025-09 Fastrack)

Effective 9/1/25, in Prototype, GCR section 9.1.8.B.K, change as follows:
"P2 cars may compete in either the Prototype class or the P2 class but must participate in the Prototype class to the extent
necessary to qualify for an invitation to the Runoffs in Prototype. P2 cars may be modified to comply with the general Prototype
rules and Prototype Engine Table or may continue to run in P2 specification in the Prototype class as permitted in Table 1 below."
Table 1 (Spec Line Cars)

A specification table follows in the original; it is not shown here.

2025-11-01 STU Non-Homologated Engine Swaps - Specifically K24A2 w/ Honda CRZ

#38746 from William Rori · Rule change · TB 25-09 (2025-09 Fastrack)

In STU Spec Lines, Table B: Alternate Vehicle and Engine Allowances, Honda K24, change Weight as follows:
"(Effective 11/1/2025) Chart + 2%"

2025-11-01 T4 02-06 Mini Cooper Gear Ratios

#38966 from Trenton Kramer · Rule change · TB 25-11 (2025-11 Fastrack)

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"

2025-11-01 T4 Reinstatement of the 2005-2010 Cobalt into T4

#38987 from Tim Little · Rule change · TB 25-11 (2025-11 Fastrack)

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.

2025-11-01 T4 Request to Classify Mercedes C230K

#39080 from Patrick Morgan · Rule change · TB 25-11 (2025-11 Fastrack)

In T4 Spec Lines, classify Mercedes C230 Kompressor (2002-2005) as follows:

A specification table follows in the original; it is not shown here.

2025-11-01 T4 ND Gearset Request for T4

#39166 from Josh Smith · Rule change · TB 25-11 (2025-11 Fastrack)

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

2025-11-01 T4 E&O wheel size on ND

#39168 from Josh Smith · Rule change · TB 25-11 (2025-11 Fastrack)

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

2025-11-01 T4 ND Spec Lines Wrong PT#'s

#39170 from Josh Smith · Rule change · TB 25-11 (2025-11 Fastrack)

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

Applies to Mazda MX-5 on this page: Oscar Jackson

Applies to Mazda Miata on this page: Kristina Etherington, Kayla Etherington

2025-11-01 T4 Touring 4 Post-Runoffs BOP Adjustments and Changes

#39251 from Touring Committee · Rule change · TB 25-11 (2025-11 Fastrack)

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:

Applies to Mazda MX-5 on this page: Oscar Jackson

2025-12-01 STU Turbo Inlet Restrictor Table

#38961 from John Weisberg · Rule change · TB 25-12 (2025-12 Fastrack)

In GCR, Section 9.1.4.H.3, change chart as follows:

A specification table follows in the original; it is not shown here.

2025-12-01 STU 275 Tire Rule

#38983 from Peter Federlin · Rule change · TB 25-12 (2025-12 Fastrack)

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."

2025-12-01 T4 Classing 1995-99 Dodge Neon SOHC

#39285 from Preston Obremski · Rule change · TB 25-12 (2025-12 Fastrack)

In T4 Spec Lines, classify Dodge/Plymouth Neon ACR SOHC/DOHC (2/4 door) (95-99) as follows:

A specification table follows in the original; it is not shown here.

2025-12-01 STU STU Honda Engine weight penalty

#39375 from Super Touring Committee · Rule change · TB 25-12 (2025-12 Fastrack)

In STU Spec Lines, Table B: Alternate Vehicle and Engine Allowances, change Minimum Weight as follows:
Honda K20: "Chart + 2%"
Honda K24: "Chart + 2%"

2026-01-01 T4 Alternate Placement of Fuse Panel and Electronics Request

#39370 from Aaron Stehly · Rule change · TB 26-01 (2026-01 Fastrack)

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."

2026-01-01 P Request to Continue to Allow Carbon Brakes

#39476 from Jeffrey Lederman · Rule change · TB 26-01 (2026-01 Fastrack)

In Prototype, GCR section 9.1.8.B.F.2, change as follows:
"Brake calipers may be ferrous or aluminum alloy. Effective 1/1/2026, carbon-carbon and carbon-ceramic brake rotors are
prohibited and rotors must be ferrous. Brake rotor material is unrestricted."

2026-01-01 T4 Clarify T4 Brake Rotor Allowance

#39503 from David Mead · Rule change · TB 26-01 (2026-01 Fastrack)

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."

2026-01-01 STU Request for Permission on Aftermarket Turbo Kit and Intake

#39529 from John Grim · Rule change · TB 26-01 (2026-01 Fastrack)

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

2026-02-01 T4 T4 and T3 Feedback

#39230 from Tim Myers · Rule change · TB 26-02 (2026-02 Fastrack)

In T4 Spec Lines, remove Ford Mustang V6 (05-14) in its entirety.

2026-02-01 T4 T4 Mustang 4.0

#39489 from Scotty B White · Rule change · TB 26-02 (2026-02 Fastrack)

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

2026-02-01 T4 Allow Alt Bushing Material in Toe Links

#39607 from David Mead · Rule change · TB 26-02 (2026-02 Fastrack)

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