STU + EP + AS at Buttonwillow Raceway Park

2024-03-01 AS Request to Classify 1970-1981 Camaro and Firebird in AS

#33659 from Brandon Vivian · Rule change · TB 24-03 (2024-03 Fastrack)

In AS Spec Lines, classify Chevrolet Camaro, Pontiac Firebird (70-81) Full Prep as follows:
AS Wheelbase Gear Ratios
Std. (or Alt.)
Brakes
(Max)
(in/mm)
Weight (lbs) Notes:

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

2024-03-01 AS Fuel Cell 12

#34194 from Clark Cambern · Rule change · TB 24-03 (2024-03 Fastrack)

In AS Spec Lines, add to Notes as follows:
Cadillac CTS-V (04-07): “Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is taken
from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a safety fuel cell.”
Chevrolet/Pontiac Camaro & Firebird (93-02): “Fuel cells must be located within 24 inches of the standard tank. The 24 inch
measurement is taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with
installation of a safety fuel cell.”
Chevrolet/Pontiac Camaro & Firebird (93-02): “Fuel cells must be located within 24 inches of the standard tank. The 24
inch measurement is taken from the perimeter of the stock and alternative fuel cell. Fuel filler location is unrestricted with

2024-03-01 AS Please Classify the 6th Gen Into AS.

#35448 from Daniel Richardson · Rule change · TB 24-03 (2024-03 Fastrack)

In AS Spec Lines, classify Chevrolet Camaro (16-) Full Prep as follows:
AS
Wheelbase Gear Ratios
Std. (or Alt.)
Brakes
(Max)
(in/mm)
Weight (lbs) Notes:

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

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 EP GCR Correction - Redundant HP Spec Lines

#35623 from Production Committee · Rule change · TB 24-03 (2024-03 Fastrack)

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

2024-03-01 AS spec lines

#35713 from American Sedan Committee · Rule change · TB 24-03 (2024-03 Fastrack)

In AS Spec Lines, classify Ford Mustang GT (05-14) with Restricted prep Engine as follows:
AS
Wheelbase Gear Ratios Std.

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

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2024-04-01 AS Restricted Prep Aftermarket Parts Request

#35682 from Tom Aquilante · Rule change · TB 24-04 (2024-04 Fastrack)

In AS Spec Lines, Chevrolet/Pontiac Camaro & Firebird (93-02), add to Notes the following:
"For the LS1connecting rods Callies p/n CSC6100DS6A2AH, Scat rods p/n 2-1CR6100-944, GM performance rods p/n 12649190."
In AS Spec Lines, Pontiac GTO (04-06), add to Notes the following:
"For the LS1connecting rods Callies p/n CSC6100DS6A2AH, Scat rods p/n 2-1CR6100-944, GM performance rods p/n 12649190."

2024-04-01 AS Allowance of 11

#35824 from American Sedan Committee · Rule change · TB 24-04 (2024-04 Fastrack)

In AS Spec Lines, Cadillac CTS-V (04-07), add to Notes the following:
"11" wide wheels can be used until 3/1/25."
In AS Spec Lines, Chevrolet Camaro SS (V8) (10-15), add to Notes the following:
"11" wide wheels can be used until 3/1/25."
In AS Spec Lines, Dodge Challenger (08-20), add to Notes the following:
"11" wide wheels can be used until 3/1/25."
In AS Spec Lines, Ford Mustang GT 5.0l (15-17), add to Notes the following:
"11" wide wheels can be used until 3/1/25."

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2024-05-01 AS 6th gen Camaro limited prep

#35733 from American Sedan Committee · Rule change · TB 24-05 (2024-05 Fastrack)

In AS Spec Lines, classify Chevrolet Camaro 1LE (2016-) as follows:
AS Wheelbase Gear Ratios Std. (or Alt.)
Brakes
(Max)
(in/mm)
Weight (lbs.) Notes:
Chevrolet
Camaro, 1LE

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

2024-05-01 AS Chevrolet/Pontiac Camaro & Firebird (82-92) 5.7L V8 LS1 Alum BLK

#35825 from Desi Colon · Rule change · TB 24-05 (2024-05 Fastrack)

In AS Spec Lines, classify Chevrolet/Pontiac Camaro & Firebird (82-92) 5.7L V-8 LS1 (Aluminum Block, Aluminum Heads) 2 valves
per cylinder, as follows:
AS Wheelbase Gear Ratios Std.

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

2024-05-01 AS Full Prep Head

#35891 from American Sedan Committee · Rule change · TB 24-05 (2024-05 Fastrack)

In AS Spec Lines, Chevrolet/Pontiac Camaro & Firebird (82-92), add to Notes the following:
"Flo Tek Head part #102-500 are permitted."
In AS Spec Lines, Chevrolet/Pontiac Camaro & Firebird (93-02), add to Notes the following:
"Flo Tek Head part #102-500 are permitted."
In AS Spec Lines, Chevrolet Camaro (10-15), add to Notes the following:
"Flo Tek Head part #102-500 are permitted."
In AS Spec Lines, Ford Mustang Incl. Cobra & Cobra R (79-93) and Mercury Capri (79-86), add to Notes the following:
"Flo Tek Part # 203-500 are permitted."

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2024-06-01 AS Request for Classification of 2018-2023 mustang In

#35764 from Michael Kamalian · Rule change · TB 24-06 (2024-06 Fastrack)

AS Spec Lines, classify Ford Mustang GT 5.0L (2018-) as follows:
AS Wheelbase Gear Ratios

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

2024-06-01 EP NIssan 300ZX Z31 to EP

#35830 from Murphy Nichols · Rule change · TB 24-06 (2024-06 Fastrack)

In EP Spec Lines, classify Nissan 300ZX (84-89), as follows:

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

2024-06-01 EP RX7 1993 and Up Request In EP Spec Lines, classify

#36031 from Edward Zabinski · Rule change · TB 24-06 (2024-06 Fastrack)

Mazda RX-7 (92-97) as follows:

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

2024-06-01 EP Clean-up Multiple EP RX-8 Spec Lines In EP

#36156 from Production Committee · Rule change · TB 24-06 (2024-06 Fastrack)

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.

2024-08-01 EP Errant entry in HP production line item

#36231 from Angus Crome · Rule change · TB 24-08 (2024-08 Fastrack)

In HP Spec Lines, change Track (F/R)mm/(in.) as follows:
Volkswagen Golf (GTI, GT, GL) (85-92): "2 1537/1529 (60.5/60.2)"
Volkswagen Jetta (GLI, GL) (85-92): "2 1537/1529 (60.5/60.2)"

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"

2024-09-01 AS Mustang transmission ratios

#36662 from American Sedan Committee · Rule change · TB 24-09 (2024-09 Fastrack)

In AS Spec Lines, Ford Mustang GT (05-14) with Restricted Prep Engine, add to Notes as follows:
"Alternate transmission Ratios 3.66, 2.43, 1.69, 1.32, 1.00, .68.”
In AS Spec Lines, Ford Mustang GT 5.0L (2018-), add to Notes as follows:
"Alternate transmission Ratios 3.24, 2.10, 1.42, 1.00, 0.81, .062."

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2024-11-01 EP 1275 HP Spridget Level 2 Only

#36518 from Darryl Saylor · Rule change · TB 24-09 (2024-09 Fastrack)

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"

2024-11-01 EP NA Miata Track Width Correction

#36902 from Production Committee · Rule change · TB 24-11 (2024-11 Fastrack)

In EP Spec Lines, Track (F/R) mm/(in.), change as follows:
Mazda MX-5 /Miata 1.6L (-1993) - "1478/1491 (58.2/58.7) 1516/1534 (59.7/60.4)"
Mazda MX-5 /Miata 1.8L (90-97) - "1483/1509 (58.4/59.4) 1516/1534 (59.7/60.4)"
Mazda MX-5 /Miata (94-97) - "1483/1509 (58.4/59.4) 1516/1534 (59.7/60.4)"

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."

2024-12-01 EP Triumph GT6 Adjustments

#37112 from Anthony Parker · Rule change · TB 24-12 (2024-12 Fastrack)

In EP Spec Lines, make the following changes in the "Triumph GT6" spec line:
Carburetor No. & Type: (2): "1.5” 1.75" Auto-type carburetor(s)"
Notes: "Two (2) 1.75” auto-type carburetors @ 1940 lbs. Three (3) Weber 40 DCOE on IR manifold with 28mm chokes @ 1990
lbs. Laycock overdrive, May use 5 speed gearbox w/o overdrive."

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 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.

2025-01-01 AS Increase Coyote Engine Restrictor to 80mm

#36177 from Gregory Eaton · Rule change · TB 25-01 (2025-01 Fastrack)

In AS Spec Lines, add to Notes as follows:
Ford mustang (GT 05-14): "Gen 1- 67mm Gen 2-64mm"
Ford mustang (GT 05-14): "Gen 1- 67mm"
Ford mustang (GT 15-17): "Gen 1- 67mm"
Ford mustang (GT 94-04): "Gen 1- 67mm Gen 2-64mm"
Ford mustang cobra & Cobra R Mercury Capri (79-93) (79-86): "Gen 1- 67mm Gen 2-64mm"

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 AS Performance Pack for 2015+ Mustang

#36867 from Michael Kamalian · Rule change · TB 25-01 (2025-01 Fastrack)

In AS Spec Lines, Ford Mustang Coupe GT (05-14) Restricted Prep., change Notes as follows:
"The 4.6L engine assembly has a weight reduction of 300 lbs. 5.0L/6spd engine/trans: track pack front and rear spoiler allowed."
In AS Spec Lines, Ford Mustang Coupe GT (05-14) with Restricted Prep. engine, change Notes as follows:
"Max. Wheel Size: Dia.18.0 inches. Stock brakes or alternate Ford 14” Brembo Brake (Ford Racing Kit #M-2300-S) and full prep
brake package may be used. Either engine may be used. 1st Generation 5.0l Coyote 11-14 62mm FPR 2nd Generation 5.0l
Coyote 15-17 61mm FPR Cold Air Intake allowed Charge Motion Control Valves can be blocked off and removed for firewall
clearance Allow Cold Air Intake Tremec Magnum transmission may be used P/N- TUKT16901. Full Prep Transmissions rule
package may also be used. Max compression ratio, 11.2:1 track pack front and rear spoiler allowed. Alternate transmission

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2025-01-01 EP Request to Reduce Weight of BMW 325i/is E30 (84-91) Spec Line

#37119 from Tim Schreyer · Rule change · TB 25-01 (2025-01 Fastrack)

In EP SPEC LINES, BMW 325i/is (E30) (84-91), change Weight as follows:
"2200 2150
*2255 2204
**2310 2258"

2025-01-01 AS Gear Ratios

#37131 from Timothy White · Rule change · TB 25-01 (2025-01 Fastrack)

In AS Spec Lines, change Gear Ratios as follows:
Cadillac CTS-V (04-07):
"2.97, 2.07, 1.43,1.00, 0.84,0.56 or 3.01, 2.07, 1.43, 1.0, .84, .57 or 2.20, 1.64,1.28,1.00 or 2.88, 1.91, 1.33, 1.00"
Chevrolet Camaro, Pontiac Firebird (70-81), Full Prep:
"3.42, 2.28, 1.45, 1.00 or 2.95, 1.94, 1.34, 1.00, 0.73 or 3.35, 1.93, 1.29, 1.00, 0.61, or 2.20, 1.64,1.28,1.00 or 2.87,1.89,1.28,1.00"
Chevrolet Camaro, Pontiac Firebird (70-81), Restricted Prep.:
"3.42, 2.28, 1.45, 1.00 or 2.95, 1.94, 1.34, 1.00, 0.73 or 3.35, 1.93, 1.29, 1.00, 0.61, or 2.20, 1.64,1.28,1.00 or 2.87,1.89,1.28,1.00"
Chevrolet/Pontiac Camaro & Firebird (82-92) Full Prep:

2025-01-01 AS ECU specs for LS engine

#37208 from Gary Mathews · Rule change · TB 25-01 (2025-01 Fastrack)

In AS SPEC LINES, Cadillac CTS-V (04-07) Restricted Prep., change Notes as follows:
"Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is taken from the perimeter of the
stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a safety fuel cell. Tremec TR6060
Transmission with 3.0 1, 2.07, 1.43, 1.0, .84, .57 ratios permitted. 11” wide wheels can be used until 3/1/25. Any ECM may be
used."
In AS SPEC LINES, Chevrolet Camaro, Pontiac Firebird (70-81) Restricted Prep ., add to Notes as follows:
"Any ECM may be used."
In AS SPEC LINES, Chevrolet/Pontiac Camaro & Firebird (82-92) 5.7L V-8 LS1, add to Notes as follows:

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."

2025-02-21 EP Effective date for Jan 2025 GCR updates

#37654 from Doug Piner · Rule change · TB 25-02 (2025-02 Fastrack)

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."

2025-03-01 EP Request Competition Adjustment to BMW Z3 2.5L

#37120 from Tim Schreyer · Rule change · TB 25-01 (2025-01 Fastrack)

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."

2025-03-01 EP Interpretation of Production Rules on Mirrors

#37235 from Lawrence Slivinski · Rule change · TB 25-03 (2025-03 Fastrack)

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."

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 EP Weight Reduction for Honda S2000

#37466 from Michael Unger · Rule change · TB 25-03 (2025-03 Fastrack)

In EP, Spec Lines make the following weight changes:

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

2025-03-01 EP Mazda 1999 Miata 1.8L

#37488 from Joe Carr · Rule change · TB 25-03 (2025-03 Fastrack)

In EP Spec Lines, make the following weight change:
Mazda MX-5 /Miata (99-05):
"2150 2100
*2204 2153
**2258 2205"

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 AS Race memo

#37902 from American Sedan Committee · Rule change · TB 25-03 (2025-03 Fastrack)

In AS Spec Lines, change Notes as follows:
Cadillac CTS-V (04-07) Restricted Prep. 6.0L V8 (Aluminum block, Aluminum heads), LS2, 2 valves/cylinder:
"Any ECM maybe used."
Chevrolet Camaro, Pontiac Firebird (70-81) Restricted Prep. 6.2L V8 (Aluminum Block, Aluminum Heads), 2 valves per cylinder:
"Any ECM maybe used."
Chevrolet/Pontiac Camaro & Firebird (82-92)s 5.7L V-8 LS1 (Aluminum Block, Aluminum Heads) 2 valves per cylinder:
"Any ECM maybe used."
Chevrolet/Pontiac Camaro & Firebird (93-02):

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"

2025-04-01 AS Flotek Head Plunge Cut Inconsistencies

#37502 from Pamela Richardson · Rule change · TB 25-04 (2025-04 Fastrack)

In GCR, Section 9.1.6., replace Figure 1 Value Seat Cutting Dimensions with the following:

2025-04-01 AS Notes clean up

#37693 from American Sedan Committee · Rule change · TB 25-04 (2025-04 Fastrack)

In AS Spec Lines, change/add to Notes as follows:
Cadillac CTS-V (04-07):
"Fuel cells must be located within 24 inches of the standard tank. The 24 inch measurement is taken from the perimeter of the
stock and alternative fuel cell. Fuel filler location is unrestricted with installation of a safety fuel cell. Any ECM maybe used. The
Drive Shaft Shop, Axle shaft part #'s 510220/510221 permitted."
Chevrolet Camaro, Pontiac Firebird (70-81) Full Prep:
"Engine built to A/S Build Sheet specifications with the following: Head Casting #s: 14101081, 14014416 Port Volume (Max.): 081
casting: 170.00 cc IN/65.00 EX; 416 Casting 168.00cc IN/60.00 EX with a 250 lb. weight reduction. Edelbrock Cylinder Head Part

2025-04-01 EP Request for Classification of Chevrolet Spark

#37755 from Kristian Smith · Rule change · TB 25-04 (2025-04 Fastrack)

In HP Spec Lines, classify the Chevrolet Spark (16-22):

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

2025-04-01 EP Request to Lower Ford Festiva Minimum Weight to 1600 LBS

#37939 from Doug DeRonne · Rule change · TB 25-04 (2025-04 Fastrack)

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”."

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 AS Errors and Omission

#38055 from American Sedan Committee · Rule change · TB 25-05 (2025-05 Fastrack)

In AS Spec Lines, Ford Mustang GT 5.0l (15-17), Flat Plate Restrictor Size, change as follows:
"67mm 64mm"

2025-05-01 AS Request to Add LS1/LS6 Intakes for 5.3L Truck Engine EnO

#38197 from Jim Clark · Rule change · TB 25-05 (2025-05 Fastrack)

In GCR, Section 9.1.6.F., add the following to Intake Part #’s:
"17113697, 19418185, 89017230, 89017363, 89017364, and 89017365, 12561269 and 88894095"

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 AS Errors and Omissions

#38234 from American Sedan Committee · Rule change · TB 25-06 (2025-06 Fastrack)

In AS Spec Lines, Ford Mustang GT (05-14) with Restricted Prep Engine, add to Gear Ratios the following:
"or 3.66, 2.43, 1.69, 1.32, 1.00, .65"

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2025-06-01 EP Base Weight Adjustment for H-Production X1/9 Spec Lines

#38255 from Matthew Brannon · Rule change · TB 25-06 (2025-06 Fastrack)

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”

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 AS RE: Previous Letter 37695 Update

#38245 from Michael Kamalian · Rule change · TB 25-07 (2025-07 Fastrack)

In AS Spec Lines, Ford Mustang GT 5.0 (2018-), change Weight as follows:
"3600 3525"

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe

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 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.

2025-07-01 EP BMW Z4 update

#38490 from Bryce McGuire · Rule change · TB 25-07 (2025-07 Fastrack)

In EP Spec Lines, BMW Z4 (03-05), add to Notes the following:
“52mm Flat Plate Intake Restrictor.”

2025-07-01 EP EP Fiat 124 Spider Competition Adjustment Request

#38498 from John Baucom · Rule change · TB 25-07 (2025-07 Fastrack)

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."

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"

2025-09-01 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"

2025-10-01 EP HP Plymouth Arrow spec omission

#38995 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)

In HP Spec Lines, Plymouth Arrow (76-80), add the following wording to Trans. Speeds(max):
"4 or 5"

2025-10-01 EP Add Wheel Diameter to Appendix G

#39008 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)

In Appendix G.2.3, change as follows:
"Rim width and diameter are is absolute maximums."

2025-10-01 EP Add TB ID tolerance to general Prod rules

#39009 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)

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)."

2025-11-01 AS Cadillac CTS-V BOP Weight Change

#38640 from Alex Lozano · Rule change · TB 25-09 (2025-09 Fastrack)

In AS Spec Lines, Cadillac CTS-V (04-07) Restricted Prep., change Weight as follows:
"(Effective 11/1/2025) 3450 3400"

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 EP Please Lower Weight of 280Z

#38871 from Matthew Miller · Rule change · TB 25-09 (2025-09 Fastrack)

In EP Spec Lines, Nissan 280Z, change Weight (lbs) as follows:
"(Effective 11/1/2025) 2560 2400
*2624 2460
**2688 2520"

2025-11-01 EP Miata Weight Adjustment Follow Up

#38949 from Don Tucker · Rule change · TB 25-10 (2025-10 Fastrack)

In EP Spec Lines, Mazda MX-5 / Miata 1.8L (90-97), Effective 11/1/2025 make the following weight change:
"2150 2125"

2025-11-01 EP 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"

2025-11-01 EP HP Volvo 142 spec omission

#38994 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)

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”."

2025-11-01 EP HP Mini DOHC 1.6

#38996 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)

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"."

2025-11-01 EP Add to Rabbit description

#39019 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)

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)"

2025-11-01 EP Clean-up 9.1.5.E.7e

#39025 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)

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

2025-11-01 EP Add TB size to Ford Mustang (94-98) Spec Line

#39130 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)

In EP Spec Lines, Ford Mustang (94-98) add the following to the Fuel Injected Equipped Throttle Body Inside Diameter column:
"60"

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 AS 1994 Mustang Spec Line Request

#39104 from Barry Borgschatz, Jr · Rule change · TB 25-12 (2025-12 Fastrack)

In AS Spec Lines, Ford Mustang GT(94-04) with Restricted Prep Engine, add to notes the following:
"Ford Motorsport #M-6250-F303 camshaft is permitted."

Applies to Ford Mustang on this page: Roger Eagleton, Ross Murray, Matt Lituchy, Michael Lowe, Pratt Cole

2025-12-01 EP TR2 Notes E&O

#39180 from Anthony Parker · Rule change · TB 25-12 (2025-12 Fastrack)

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."

2025-12-01 EP Balance of Power

#39187 from Jim Simaras · Rule change · TB 25-12 (2025-12 Fastrack)

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"

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 EP Request to Update E30 BMW Throttle Body Diameter Verbiage

#39363 from Tim Schreyer · Rule change · TB 26-01 (2026-01 Fastrack)

In EP Spec Line BMW 325i/is E30 (84-91), change Drivetrain Notes as follows:
"Fuel Injection, TB: 60mm"

2026-01-01 AS Restrictor Plate Change for Gen 2 Ford Coyote Engine

#39501 from American Sedan Committee · Rule change · TB 26-01 (2026-01 Fastrack)

In AS Spec Lines, change Restrictor as follows:
Ford Mustang Incl. Cobra and Cobra R (79-93) and Mercury Capri (79-86) with Restricted Prep Engine: "64 mm 61 mm"
Ford Mustang GT (94-04) with Restricted Prep Engine: "64 mm 61 mm"
Ford Mustang Coupe GT (05-14) Restricted Prep 5.0L/6 speed 4 valves per cylinder: "64 mm 61 mm"
Ford Mustang GT (05-14) with Restricted Prep Engine: "64 mm 61 mm"
Ford Mustang GT 5.0L (15-17) Restricted Preparation: "64 mm 61 mm"

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 AS Edelbrock manifold (& timing kit) to Chevy LS Spec Lines Request

#39055 from Jason Smith · Rule change · TB 26-01 (2026-01 Fastrack)

In GCR, Section 9.1.6.D.2.h.2., add the following:
"(Effective 2/1/2026) i. Weight based on full preparation chassis choice spec line for GM LM7 5.3L
Carburetor Option:
Must use the full prep 4776 holly carburetor and spacer gasket
Edelbrock Performer RPM 71187 intake manifold
MSD 6014 ignition box
(Edelbrock part # kit 7118)"