wordingMultiple classes standardize spelling: 'drive train' and 'Power Train' become 'drivetrain' and 'Powertrain' throughout rules.
As printed in Fastrack
In Appendix F. Technical Glossary, change as follows: Drive Shaft: "drive train drivetrain" Gear: "drive train drivetrain" Hand Brake: "drive train drivetrain" Power Train: "Power Train Powertrain – Consists of the combination of an internal combustion Engine and Drive Train Drivetrain components." Pressure Plate: "drive train drivetrain" Sub-frame/Cross Member: "drive train drivetrain"
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Universal Joint: "drive train drivetrain" In FORMULA VEE PREPARATION RULES, GCR section 9.1.1.C.1.B, change as follows: "No component of the engine, power train powertrain" In FORMULA FIRST PREPARATION RULES, GCR section 9.1.1.H.1.2, change as follows: "No component of the engine, power train powertrain" In FORMULA ENTERPRISES (FE) SPECIFICATIONS, GCR section 9.1.1.I.2.T.d, change as follows: "drive train drivetrain" In FORMULA ENTERPRISES (FE) SPECIFICATIONS, GCR section 9.1.1.I.2.T.e, change as follows: "drive train drivetrain" In FORMULA ENTERPRISES (FE) SPECIFICATIONS, GCR section 9.1.1.I.2.U, change as follows: "Drive Train Drivetrain" In FORMULA ENTERPRISES (FE) SPECIFICATIONS, GCR section 9.1.1.I.2.U.b, change as follows: "drive train drivetrain" In FORMULA ENTERPRISES (FE) SPECIFICATIONS, GCR section 9.1.1.I.2.U.f, change as follows: "drive train drivetrain" In Grand Touring Category Specifications, GCR section 9.1.2.F.7.a.3, change as follows: "drive train drivetrain" In Grand Touring Category Specifications, GCR section 9.1.2.F.7.e, change as follows: "Drive Train Drivetrain" In Grand Touring Category Specifications, GCR section 9.1.2.F.7.e.4, change as follows: "drive train drivetrain" In Grand Touring Category Specifications, GCR section 9.1.2.F.7.e.5, change as follows: "drive train drivetrain" In GTL Spec lines, Engines - FIAT, 1500 Limited Prep (Engine & Chassis), change notes as follows: "Drive train Drivetrain" In Production Category, GCR section 9.1.5.C.1, change as follows: "drive train drivetrain" In Production Category, GCR section 9.1.5.E.1, change as follows: "Drive Train Drivetrain" In Production Category, GCR section 9.1.5.E.1.a, change as follows: "Drive Train Drivetrain" In Production Category, GCR section 9.1.5.E.1.a.1, change as follows: "Stock and permitted alternate components of the drive train drivetrain can be modified by any mechanical or chemical means. Modification of a drive train drivetrain" In Production Category, GCR section 9.1.5.E.1.a.3, change as follows: "drive train drivetrain" In Production Category, GCR section 9.1.5.E.1.o.6, change as follows: "drive train drivetrain" In Production Category, GCR section 9.1.5.E.2, change as follows: "Drive Train Drivetrain" In Production Category, GCR section 9.1.5.E.2.a, change as follows: "Drive train Drivetrain" In Production Category, GCR section 9.1.5.E.2.a.1, change as follows: "Stock and permitted alternate components of the drive train drivetrain can be modified by any mechanical or chemical means. Modification of a drive train drivetrain" In Production Category, GCR section 9.1.5.E.2.a.3, change as follows: "drive train drivetrain" In Production Category, GCR section 9.1.5.E.2.o.6, change as follows: "drive train drivetrain" In Production Category, GCR section 9.1.5.E.3, change as follows: "Drive Train Drivetrain" In HP, Fiat X-1/9 1500 spec line, change Notes as follows: "Drive train Drivetrain" In SPORTS RACING CATEGORY, GCR Section 9.1.8.1, change as follows: "Effective 1/1/97, those cars formerly known as Sports Renault and/or Spec Racers or any variants of this chassis/drive train drivetrain/bodywork combination will not be allowed to compete in ASR in any SCCA sanctioned event."
Correct Fiat X1/9 level 1 brakes to reflect FP line
unclearFP and HP Fiat X-1/9 1300 Level 1 now permit intake manifolds 128BS and 128AS.
As printed in Fastrack
In FP spec lines, Fiat X-1/9 & Bertone 1300 (Prep. Level 1), add the following wording to the Drivetrain Notes section: "Intake manifold part numbers 128BS and 128AS are permitted." In HP spec lines,Fiat X-1/9 1300" (Prep Level 1), add the following wording to the Drivetrain Notes section: "Intake manifold part numbers 128BS and 128AS are permitted."
inductionHP Sprite/Midget 1275 allows MG-B alternate intake manifold with 1.5" SU carbs; balance tube shortening and flange modification permitted.
As printed in Fastrack
In HP Spec Lines, Austin-Healey Sprite Mk I, II, III, IV MG Midget Mk I, II, III, IV & 1500, change Drivetrain Notes as follows: "(2) 1.25” SU w/ no modifications (2) 1.5” SU w/ no modifications (on alternate manifold) Valves: (I) 33.0/(1.30) (E) 29.5/(1.16) Comp. ratio 12.0:1, Valve lift .450” Trans. Speeds: 4 Drivetrain Level 2 preparation only. Listed spec line weight does not change with alternate or stock transmission.
A specification table follows in the original; it is not shown here.
fasterHP Honda Civic DX/LX (92-95) wheels widen to 15x7, weight drops to 2350 lbs.
As printed in Fastrack
In HP, make the following changes to the "Honda Civic DX (92-95)" spec line: Spec Line Name: "Honda Civic DX/LX (92-95)" Wheels: "13x7 15x7" Wheelbase: "2/ 4 door: 2621/(103.2) 2/3 door: 2573/(101.3)" Weight: "2420 2350"
fasterHP Austin-Healey Sprite and MG Midget 1275 permitted to use 1.5" SU carbs on alternate manifold with narrowed balance tube.
As printed in Fastrack
In HP Spec Lines, Austin-Healey Sprite Mk I, II, III, IV MG Midget Mk I, II, III, IV & 1500, change Drivetrain Notes as follows: "(2) 1.25” SU w/ no modifications (2) 1.5” SU w/ no modifications (on alternate manifold) Valves: (I) 33.0/(1.30) (E) 29.5/(1.16) Comp. ratio 12.0:1, Valve lift .450” Trans. Speeds: 4 Drivetrain Level 2 preparation only. Listed spec line weight does not change with alternate or stock transmission.
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Alternate intake manifold, with narrowed balance tube to fit 1275cc head, permitted with use of 1.5” SU carbs (original P/N’s 12H708, 12H1398, 12H2568)." In HP Spec Lines, Austin-Healey Sprite Mk I, II, III, IV MG Midget (ALL), change Drivetrain Notes as follows: "(2) 1.25” SU w/ no modifications (2) 1.5” SU w/ no modifications (on alternate manifold) Valves: (I) 33.0/(1.30) (E) 29.5/(1.16) Comp. ratio 12.0:1, Valve lift .450” Trans. Speeds: 4 Alternate intake manifold, with narrowed balance tube to fit 1275cc head, permitted with use of 1.5” SU carbs (original P/N’s 12H708, 12H1398, 12H2568)."
wordingHP class mid and rear engine cars may add single inlet and outlet holes for oil cooler ducting in front bodywork.
As printed in Fastrack
In GCR, Section 9.1.5.E.6.g.4, add the following: "On mid and rear engine cars, a single inlet hole may be cut in the front bodywork and a single outlet hole may be cut in the front trunk floor or a wheel well, for the sole purpose of ducting air to a single engine oil cooler. The size of these holes may be no larger than the area of the oil cooler itself."
fasterHP Triumph Spitfire 1296cc compression ratio increases from 11.0 to 12.0:1.
As printed in Fastrack
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
unclearEP Triumph TR2-TR4A allows 5-speed gearbox without overdrive; removes Weber carb and weight specification.
As printed in 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."
slowerHP Volvo 142/142E gains compression ratio limit 12.0:1 and valve lift limit .425".
As printed in 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”."
slowerHP Mini Cooper 07-15 valve lift reduced to .390", from .450".
As printed in 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"."
wordingFP and HP Volkswagen Rabbit descriptions updated: Convertible changed to Cabriolet in FP; Cabriolet added to three HP engine variants.
As printed in 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)"
wordingEP, FP, HP: rear drum brake to disc conversion clarified; rotors solid, diameter limited to largest front rotor permitted.
As printed in 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
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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."
wordingEP, FP, HP throttle body inside dimensions must remain stock with +/-.25mm tolerance; butterfly dimensions stock in FP, HP only.
As printed in 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)."
fasterHP Ford Festiva 88-93 minimum weight drops to 1600 lbs, variants to 1640 and 1680 lbs; compression ratio raised to 11.0:1.
As printed in 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”."
slowerHP Mini Cooper 07-13 engine corrected to DOHC; valve lift limit reduced to 0.390 inches.
As printed in Fastrack
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"."
fasterHP Sprite and Midget 1275cc and 1098cc Level 2 compression ratio raised to 12.0:1.
As printed in 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"
Request for Classification of 1989-1994 Suzuki Swift GT 16V Twin
wordingEP Mazda RX-8 (04-11) alternate spec line removed; one primary line remains.
As printed in 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.
wordingHP Honda CRX/Si 84-87 plastic panels can be replaced with replica alternate material if stock appearance maintained.
As printed in Fastrack
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."
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
fasterHP Sprite/Midget Mk I–IV, Mk 1500 compression ratio raised to 12.0:1 at Prep Level 1/2.
As printed in Fastrack
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"
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."
fasterEP Honda S2000 fuel injected throttle body inside diameter increases from 62mm to 64mm.
As printed in Fastrack
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."
Front Header/Nose Panel Alternate Material For 84-87 CRX
wordingHP Honda CRX/Si 84-87 front header/nose panel may use alternate material if appearance remains stock.
As printed in Fastrack
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."
wordingEP Triumph TR8 dry sump allowance moved from carburetor line to notes section.
As printed in Fastrack
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.”
cars addedEP Porsche 944/924S combines 2.5L and 2.7L variants with new weights: 2250–2415 lbs depending on engine and year.
As printed in Fastrack
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.
fasterFP Toyota Corolla 2TC loses 43 lbs to 1810; HP Corolla loses 50–52 lbs to 1910–2006.
As printed in Fastrack
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”
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."
Correct Intake Valve Size on 1500cc Midget/Spitfire
wordingFP and HP Sprite, Midget, and Spitfire 1500 intake valve size corrected to 36.6/(1.44).
As printed in Fastrack
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)"
wordingFord Fiesta HP and Chevrolet Sonic FP model year ranges extended from 2016 to 2019.
As printed in Fastrack
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)"
wordingEP, FP, HP cylinder head ports limited to 1 inch maximum depth matching from mating surface.
As printed in Fastrack
In Production Category Specifications, GCR section 9.1.5.E.2.e.5., change as follows: "Cylinder head ports may be matched to the intake and exhaust manifolds to a depth of no more than 1 inch from the port mating surface."
unclearEP Mazda RX-7 12A/13B gains fuel injection option on dual-y manifold with 42mm choke(s).
As printed in Fastrack
Effective November 1, 2022, in EP Spec Lines, change Carburetor. No. & Type as follows: Mazda RX-7 (12A/13B) (79-85): "12A: (1) Nikki 4 bbl carburetor w/ primary choke(s) bored to match secondary choke(s) on a stock manifold or (1) Auto-type 2 bbl w/42mm choke(s) on a “dual-y” manifold. 13B: (1) Auto-type 2 bbl w/ 42mm choke(s) on a “dual-y” manifold, (1) 2 bbl fuel injected throttle body w/ 42mm choke(s) on a “dual-y” manifold, or stock 13B fuel injection." Mazda RX-7 (13B) (86-91): "(1) Auto-type 2 bbl w/ 42mm choke(s) on a “dual-y” manifold, (1) 2 bbl fuel injected throttle body w/ 42mm choke(s) on a “dual- y” manifold, or stock 13B fuel injection."
Request for Corrado Stroke & Displacement Correction
wordingEP Subaru BRZ and Toyota 86/Scion FR-S model year ranges updated to 13-20.
As printed in Fastrack
In EP Spec Lines, Subaru BRZ (2013), change title changes: "Subaru BRZ (13 - 20)" In EP Spec Lines, Toyota Scion FR-S (2013), change title changes: "Toyota 86 / Scion FR-S (13 - 20)"
slowerEP Mazda MX-5 Global Cup 16-22 minimum weight set to 2400 lbs; sequential gearbox allowed with +150 lbs penalty.
As printed in Fastrack
Effective 05/01/2022 In EP Spec Lines, Mazda MX-5 Global Cup (16-22), change as follows: Weight (lbs): "see notes 2400" Notes: "Car preparation is limited to what is permitted by the MX-5 Global Cup rules, and the car must meet all MX-5 Global Cup rules except as otherwise indicated within this spec line. Competitors must have the current MX-5 Global Cup rules in their possession and present them upon request. Sequential gearbox is allowed with +150lbs."
fasterEP/FP/HP open cars may now use carbon fiber hardtops if they retain OEM appearance in all exterior profiles.
As printed in Fastrack
In Production Category Specifications, GCR Section 9.1.5.E.9.a.12 change as follows: "Open cars must remove convertible soft tops and all attaching bracketry and hardware. If the stock windshield is retained, OEM and aftermarket hardtops are allowed. Aftermarket hardtops must retain OEM appearance in all exterior profiles, and carbon fiber construction is not allowed. Any hardtop must be attached by positive fasteners."
In EP Spec Lines, Mazda RX-8 (04-11) (alternate), make the following changes to Carburetor. No. & Type: "Renesis: Fuel Injection. 13B: d (1) Auto-type 2 bbl carb w/ 42mm choke(s) on a “dual-y” manifold, (1) 2 bbl fuel injected throttle body w/ 42mm choke(s) on a “dual-y” manifold, or stock 13B fuel injection."
wordingEP and FP Production clarifies idle control valve rules: stock devices allowed original, removed with blocked ports, or mechanical replaced with electronic stock type.
As printed in Fastrack
In Production, GCR Section 9.1.5.E.1.b.9, add the following: "Stock/original idle control devices can be utilized in their original, unmodified location and condition, or completely removed and any resulting openings blocked off. A mechanical stock/original idle control device can be replaced with an electronic stock/original type of idle control device, with the original mechanical idle ports in the throttle body blocked off." In Production, GCR Section 9.1.5.E.2.b.9, add the following: "Stock/original idle control devices can be utilized in their original, unmodified location and condition, or completely removed and any resulting openings blocked off. A mechanical stock/original idle control device can be replaced with an electronic stock/original type of idle control device, with the original mechanical idle ports in the throttle body blocked off."
slowerEP BMW Z3 2.5L intake restrictor reduced from 59mm to 58mm flat plate.
As printed in Fastrack
Effective 3/1/2022 In EP, make changes to BMW spec lines as follows: BMW Z3 2.5L - 59 58mm Flat Plate Intake Restrictor is required with both stock or alternate throttle body. BMW 328i/is E36 (96-99) - 62mm Flat Plate Intake Restrictor is required. BMW 328i/ci E46 (01-06) - 62mm Flat Plate Intake Restrictor is required. BMW 325i/is E46 (01-06) - 60mm Flat Plate Intake Restrictor is required. BMW 325i/is E36 (92-95) - 60mm Flat Plate Intake Restrictor is required. BMW 325is M-Technic (1994) - 60mm Flat Plate Intake Restrictor is required.
fasterFord Mustang 99-03 classified to EP at 2700/2768/2835 lbs; 94-98 Mustang weight reduced to 2550/2614/2678 lbs.
As printed in Fastrack
In EP Spec Lines, Ford Mustang (94-98), change weight as follows: "2700 2550 *2768 2614 **2835 2678" In EP Spec Lines, classify Ford Mustang (99-03) as follows:
A specification table follows in the original; it is not shown here.
tyres & wheelsEP, FP, HP Improved Touring cars may use any DOT-approved tire per section 9.3.45 in Production class.
As printed in Fastrack
In Production, GCR Section 9.1.5.B.5, change as follows: "Any Improved Touring car meeting all the requirements of ITCS 9.1.3 may compete in the Production class in which the same make, model and engine displacement car is classified. For Improved Touring cars competing in Production, the level of preparation and modifications will be as determined by ITCS 9.1.3 and not by PCS 9.1.5, however any DOT approved tire as defined by 9.3.45 is allowed."
wordingEP, FP, HP classes allow stock/original idle control devices unmodified or completely removed with openings blocked.
As printed in Fastrack
In GCR, Section 9.1.5.E.1.b.1., change as follows: “All inducted air must pass through the venturi(s) of the car’s carburetor(s), except that which passes through a stock/original idle control device.“ In GCR, Section 9.1.5.E.1.b.4., change as follows: “Fuel injection: All inducted air must pass through the throttle body and be subject to control by the throttle butterfly), except that which passes through a stock/original idle control device.“ In GCR, Section 9.1.5.E.1.b., add the following: ”9. Stock/original idle control devices can be utilized in their original, unmodified location and condition, or completely removed
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and any resulting openings blocked off. “ In GCR, Section 9.1.5.E.2.b.1., change as follows: “All inducted air must pass through the venturi(s) of the cars carburetor(s), except that which passes through a stock/original idle control device. “ In GCR, Section 9.1.5.E.2.b.4., change as follows: “Fuel Injection: All inducted air must pass through the throttle body and be subject to control by the throttle butterfly), except that which passes through a stock/original idle control device. “ In GCR, Section 9.1.5.E.2.b., add the following: “9. Stock/original idle control devices can be utilized in their original, unmodified location and condition, or completely removed and any resulting openings blocked off. “
Incorrect Valve Size Changes in Jan 2022 GCR for FIAT X1/9
wordingEP, FP, HP front-wheel-drive cars may alter body and suspension to install alternate transmission, transaxle, and axle shaft.
As printed in Fastrack
In Production, GCR sections 9.1.5.E.1.n.4. and 9.1.5.E.2.n.4. change as follows: "For rear wheel drive cars, the transmission tunnel and tunnel cover can be altered to allow the installation of an alternate transmission and/or driveshaft. For front wheel drive cars, the body, unibody, frame, suspension crossmembers/subframes and their components may be altered to the extent required to allow the installation of an alternate transmission, transaxle and/or driveshaft axle shaft."
Weight Adjustment To Fiat X1/9 Spec Lines, H-Production
fasterHP Fiat X1/9 1500 loses 50 lbs to 1950; 1300 loses 45–47 lbs; Bertone 1500 loses 50–52 lbs.
As printed in Fastrack
In HP Spec Lines, make the following changes to Weight: Fiat X-1/9 & Bertone 1500 (Level 2): "1840 1790 *1886 1835 **1932 1880" Fiat X-1/9 1300 (Level 2): "1695 1650 *1737 1691 **1780 1733" Fiat X-1/9 1300 (Level 1): "2115 2060" Fiat X-1/9 1500 (Level 1/2): "2000 1950"
wordingEP BMW Z3 2.5L allows alternate throttle body from 92-95 325i with Turner adapter; head casting 1738400 permitted with specific blocks.
As printed in Fastrack
In EP Spec Lines, BMW Z3 2.5L, change Notes as follows: "Comp. Ratio Limited to 12.0:1, Valve lift limited to .500”. To replace stock drive-by-wire throttle body, a Alternate throttle body from BMW 92-95 325i (part #13541748105) is permitted only with Turner Motorsports adapter plate (part #TEN9990850) is permitted. Cylinder head casting number 1738400 permitted with use of the allowed iron block (casting number 1748933 or 1738566)."
slowerEP Porsche 944S2 89-91 requires 56mm flat plate intake restrictor; comp ratio max 12.0:1, valve lift max 0.500".
As printed in Fastrack
In EP Spec Lines, Porsche 944S2 (89-91), change Notes as follows: "Comp. Ratio limited to 12.0:1, Valve lift limited to .500”, Dry sump is allowed. 56mm Flat Plate Intake Restrictor is required. In order to facilitate the installation of the FPR, additional spacers/plates may be added to convert the mating area of the throttle body and the intake manifold into a flat surface. These pieces must maintain the stock 60mm throttle body bore, the FPR must be a separate piece that can be independently removed and measured, and the total thickness of all pieces (including the FPR) cannot add up to more than 1” in thickness. Can use the stock fuel tank if stock rear bumper and bumper support structure retained."
Classing Clarification for 1986 Toyota Corolla FX16
wordingHP Toyota MR-2 1.6L (85-89) track corrected to 15.47 inches front and rear.
As printed in Fastrack
In the HP "Toyota MR-2 1.6L (85-89)" spec line, please correct the Track column as follows: "1532 47 / 1532 47" In GCR, Section 9.1.5.C.4, please change as follows: "Track specifications will be set at 103% of the car’s stock track, plus 2.5 inches."
Request to Allow F22c Engine for 2000-2003 Honda S2000
unclearEP Lotus/Caterham 7 America carburetor changed from IT fuel injection prep to fuel injection.
As printed in Fastrack
In EP Spec Lines, Lotus / Caterham 7 America, change as follows: Carburetor No. & Type: "IT fuel injection prep Fuel injection" Notes: "Engine is limited to IT preparation except modifications permitted in sections 9.1.5.E.2.e, 9.1.5.E.2.f, and 9.1.5.E.2.h."
slowerEP, FP, HP clarifies percentage weight penalties sum first, then apply to base weight, rounding to nearest pound.
As printed in Fastrack
In GCR, Section 9.1.5.C. add as follows: "5. For percentage-based weight penalties, all applicable percentage values shall be summed first, and then applied to the vehicle’s minimum specified base weight, as listed in the PCS. The minimum vehicle weight shall be rounded to the nearest pound. For example, a car with a 1950lbs minimum specified base weight, that’s running a non-stock gear-engagement transmission and non-stock brake rotors and/or calipers, would calculate its minimum weight as follows: 5% transmission penalty + 2% brakes penalty = 7% total penalty 7% total penalty * 1950 lbs base weight = 2086.5 lbs 2086.5 lbs rounded to nearest pound = 2087 lbs minimum weight"
Correct Induction Error on new HP Mazda 626 Spec Line
unclearHP Mazda 626 (84-87) induction changed from dual 32mm sidedraft carbs to carburation or fuel injection.
As printed in Fastrack
In HP Spec Line, Mazda 626 (84-87), change Carb. No. & Type as follows: "(2) Auto-type sidedraft w/32mm choke(s) on I.R. manifold, of Carburation or fuel injection."
cars addedHP Mini Cooper classification expands to include 12-15 Coupe model in existing spec line.
As printed in Fastrack
In HP Spec Lines, Mini Cooper (07-13) (includes 09-15 convertible), change as follows: "Mini Cooper (07-13) (includes 09-15 convertible and 12-15 Coupe)"
Request clarification on VW 1.8 Rabbit GTI Spec Line
suspension & brakesEP Austin-Healey 3000 Mk. I, II, III now allows TR-6 front calipers and discs as alternate.
As printed in Fastrack
In EP, Spec Lines, Austin-Healey 3000 Mk. I, II, III, add to Brakes Alt.: mm/(in.) as follows: "Rear Disc: #H82462 Front calipers & discs from TR-6 (std. or alt)"
Mk2 VW Consistency and Cleanup of FP and HP Spec Lines
wordingEP, FP, HP Level 1 and Level 2 induction systems: clarified carburetor and fuel injection rules, jets/needles/rods unrestricted in Level 2.
As printed in Fastrack
In Production, GCR section 9.1.5.E.1.b.1, make changes as follows: "All inducted air must pass through the venturi(s) of the car’s carburetor(s). Any carburetor(s) with restricted venturi(s) must retain such venturi(s) in the original location within the carburetor. The throttle plate, shaft location, and bore diameter (as measured at the throttle plate) shall remain as specified. Carburetor jets, jet needles, metering rods and needle valves are unrestricted. Choke mechanisms, plates, rods, and actuating cables, wires, or hoses can be removed. The number and type of carburetors must not be changed from stock, unless otherwise specified by the vehicles spec line. In all other regards, standard and approved optional carburetor(s) are unrestricted. All single carbureted cars may fit a permitted optional carburetor. Where the use of one (1) 40 DCN, DCNF, IDF carburetor is
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specified, a permitted optional carburetor may be substituted. Permitted optional carburetors are:" In GCR section 9.1.5.E.1.b.4, make changes as follows: "Fuel injection: All inducted air must pass through the throttle body and be subject to control by the throttle butterfly. The stock throttle body casting/housing must be retained. The inside dimensions of the throttle body casting/housing (as measured at the throttle butterfly) and all dimensions of the throttle butterfly must remain stock, but . T the throttle body can otherwise be ported and polished. The dimensions of the throttle butterfly must remain stock. The throttle butterfly shaft shall not be relocated. The outside diameter of the portion of the throttle butterfly shaft located in the throttle body bore must be no smaller than stock. The contour of the interface between the throttle butterfly shaft and the butterfly must remain stock. The throttle butterfly and any throttle butterfly to shaft screws/bolts can be attached to the throttle butterfly shaft by any means including welding or brazing. Holes or slots can be created in the throttle butterfly for purposes of idle adjustment only. The number of injectors must remain stock. The mounting position and the injection point must be stock. Electronic fuel injection may be substituted for the stock type of fuel injection. In all other respects the fuel injection system is unrestricted." In GCR section 9.1.5.E.2.b.1, make changes as follows: "All inducted air must pass through the venturi(s) of the car’s carburetor(s). Carburetor jets, jet needles, metering rods and needle valves are unrestricted. Choke mechanisms, plates, rods, and actuating cables, wires, or hoses can be removed. The number and type of carburetors must not be changed from stock, unless otherwise specified by the vehicles spec line. In all other regards, standard and approved optional carburetor(s) must not be modified. All single carbureted cars may fit a permitted optional carburetor. Where the use of one (1) 40 DCN, DCNF, IDF carburetor is specified, a permitted optional carburetor may be substituted. Permitted optional carburetors are:"
wordingEP BMW Z3 2.5L iron block casting 1738566-C designation removed, wording clarification only.
As printed in Fastrack
In EP, BMW Z3 2.5L, make changes to the spec line as follows: "Cylinder head casting number 1738400 permitted with use of the allowed iron block (casting number 1748933 or 1738566-C).
Thank you for your letter, but this request is not recommended at this time. The vehicle in question is proven to be competitive as classed, it never came from the factory with a carburetor, and the stock fuel injection components are not difficult or expensive to obtain, so there is no justifiable reason to add this allowance to this vehicle's spec line.
slowerEP BMW 2.8L, 328i E36/E46, and 325i E36 blocks now iron only; 325i E46 aluminum only.
As printed in Fastrack
In EP, correct the following spec lines as shown: BMW Z3 2.5L, add to "Notes" section: "Cylinder head casting number 1738400 permitted with use of the allowed iron block (casting number 1748933-C)." BMW Z3 2.8L (97-00), modify "Block Mat'l" section: "Alum or Iron" BMW 328i/is E36 (96-99), modify "Block Mat'l" section: "Alum or Iron"
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BMW 328i/ci E46 (01-06), modify "Block Mat'l" section: "Alum or Iron" BMW 325i/is E46 (01-06), modify "Block Mat'l" section: "Alum or Iron" BMW 325i/is E36 (92-95), modify "Block Mat'l" section: "Alum or Iron"
wordingHP Mini Cooper model year ranges for convertibles revised: 02-06 now includes 05-08, 07-13 now includes 09-15.
As printed in Fastrack
In HP Spec Lines, change as follows: "Mini Cooper (includes convertible) (02-06) (includes 05-08 convertible)" In HP Spec Lines, change as follows: "Mini Cooper (includes convertible) (07-13) (includes 09-15 convertible)"
wordingEP Caterham 7 Spec Line removes redundant suspension note, clarifies engine prep limits and comp ratio to 10.0:1.
As printed in Fastrack
In EP, modify the "Notes" section of the "Lotus/Caterham 7 America" spec line as follows: "Level 2 suspension preparation. Engine is limited to IT preparation except modifications permitted in sections 9.1.5.E.2.e., 9.1.5.E.2.f, and 9.1.5.E.2.h. and f. Comp. Ratio limited to 10.0: 1, Valve lift limited to .380”." Note that the "Level 2 suspension preparation" limitation is already mandated by the fact that this is a "Prep Level 2" classified vehicle. Removal of that wording from the "Notes" section is purely due to redundancy, and not to change the allowed preparation.
wordingHP Volkswagen Rabbit and Scirocco 1588 remove 32mm choke requirement, clarify carburetor options and weight penalties.
As printed in Fastrack
In HP, Volkswagen Rabbit 1588 (includes Cabriolet /convertible), spec lines, change Carburetor. No & Type as follows: "(1) 40 DCN, DCNF w/ 32mm choke(s), or fuel injection. 32mm choke(s) req'd. (2) auto type side draft(s) w/ 32mm chokes at 90lbs penalty." In HP, Volkswagen Rabbit 1588 (includes Cabriolet /convertible), spec lines change Notes, as follows: "Compression ratio limited to 11.5:1, Valve lift limited to .450”. (2) auto type side draft carburetors with 32mm chokes permitted at weights of 1875/* 1922/** 1969. Mk2 VW front spindles, hubs and bearings are permitted."
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In HP, Volkswagen Scirocco 1588, spec lines, change Carburetor. No & Type as follows: "(1) 40 DCN, DCNF w/ 32mm choke(s), or fuel injection. 32mm choke(s) req'd. (2) auto type side draft(s) w/ 32mm chokes at 90lbs penalty." In HP, Volkswagen Scirocco 1588), spec lines, change Notes as follows: "Compression ratio limited to 11.5:1, Valve lift limited to .450”. (2) auto type side draft carburetors with 32mm chokes permitted at weights of 1875/* 1922/** 1969. Mk2 VW front spindles, hubs and bearings are permitted."
Request to Classify 2007 - 2013 Mini Cooper Convertible
cars addedHP Mini Cooper Convertible (07-13) newly classified; (05-08) convertible spec consolidated into main listing.
As printed in Fastrack
In HP, Mini Cooper (02-06), changes as follows: "(includes convertible)" In HP, Mini Cooper (07-13), changes as follows: "(includes convertible)" In HP, Mini Cooper (05-08), delete the spec as follows: "Mini Cooper Convertible (05-08)"
Allow HP Datsun 510 Under Level 2 to Utilize Datsun Z Brakes
In HP, Nissan/Datsun PL510, make changes to the spec line as follows: Brakes: "Factory Spec @ all 4 wheels. (F) 9.1 Disc (R) 9.0 Drum" Brakes Alt: "Nissan/Datsun 240Z/260Z/280Z front rotors and calipers and rear aluminum drums are permitted." Notes: "Compression ratio limited to 12.0:1, Valve lift limited to .450”. (2) auto type side drafts w/ 32mm choke(s) on I.R. manifold allowed @ 2050 (*2101 **2153). Nissan/Datsun 240Z/260Z/280Z front rotors
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and calipers and rear aluminum drums are permitted."
In HP, Nissan/Datsun PL510, make changes to the spec line as follows: Carburetor No & Type: "(1) 40 DCN or, DCNF w/ 32mm choke(s),. 32mm choke(s) req'd, or (1) 36mm DCNVH. (2) auto type side draft(s) w/ 32mm choke(s) on I.R. manifold @ 90lbs penalty." Notes: "Compression ratio limited to 12.0:1, Valve lift limited to .450”. (2) auto type side drafts w/ 32mm choke(s) on I.R. manifold allowed @ 2050 (*2101 **2153). Nissan/Datsun 240Z/260Z/280Z front rotors and calipers and rear aluminum drums are permitted."
fasterHP Datsun 1200 carburetor choke size increases from 26mm to 30mm.
As printed in Fastrack
In HP Spec Lines, Nissan/Datsun 1200, make changes as follows in Carburetor No. & Type: "(1) 40 DCN, DCNF, IDF, 26mm choke(s) req’d. w/ 30mm choke(s), (2) auto type side draft w/ 30mm choke(s) on I.R. manifold."
wordingHP Mazda2 updates to 11-14, Honda Fit to 15-19, Mini Cooper to 07-13.
As printed in Fastrack
In HP, Mazda2 (07-11), make change as follows: (07-11) (11-14)" In HP, Honda Fit (2015), make change as follows: (2015) (15-19)" In HP, Mini Cooper (07-11), make change as follows: (07-11) (07-13)"
wordingHP Porsche 914-4 1.8L now allows 2-stage dry sump if cam-driven and OEM-located.
As printed in Fastrack
In HP, Porsche 914-4 (1.8L), add to notes as follows: "A 2-stage dry sump is allowed, but it must be cam-driven only and mounted in the same location as the OEM oil pump."
Please Allow Alternate Rear Axle Housing for RWD Toyota Corolla
wordingFP and EP Mazda Miata models standardized to 55mm throttle body diameter; brake spec clarified.
As printed in Fastrack
In FP, Mazda Miata 1.6L (90-97), make changes as follows: Brakes Std.: "Factory spec @ all 4 wheels (F) 235 x 18 Vented Disc (R) 231 x 9 Solid Disc" Throttle body Diameter: "stock throttle body I.D. 55mm" In EP, Mazda MX-5/Miata 1.6L (-1993), make changes as follows: Brakes Std.: "(F) 235 (9.3) x 18 Vented Disc (R) 231 (9.1) x 9 Solid Disc"
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Throttle body Diameter: "stock throttle body I.D. 55mm" In EP, Mazda MX-5/Miata 1.8L (90-97), make changes as follows: Brakes Std.: "(F) 235 ( 9.3) x 18 Vented Disc (R) 231 (9.1) x 9 Solid Disc" Throttle body Diameter: "stock throttle body I.D. 55mm" In EP, Mazda MX-5/Miata (94-97), make changes as follows: Brakes Std.: "(F) 235 x 18 Vented Disc (R) 231 x 9 Solid Disc" Throttle body Diameter: "stock throttle body I.D. 55mm" In EP, Mazda MX-5/Miata (99-03), make changes as follows: Brakes Std.: "(F) 235 (9.3) x 18 Vented Disc (R) 231 (9.1) x 9 Solid Disc" Throttle body Diameter: "stock throttle body I.D. 55mm"
HP VW Rabbit Convertible 1.6L #1922 and 32mm chokes
wordingEP, FP, HP cylinder head rules reorganized for clarity; no performance change.
As printed in Fastrack
In Production, GCR section 9.1.5.E.2.e, delete section and replace as follows: e. The Cylinder Head can only be modified: 1. To install an alternate camshaft, and/or adjustable cam gears. 2. To port match on the port mating surface to a depth of no more than one inch. 3. To facilitate the installation of permitted alternate components, provided the modification serves no other function. 4. To achieve the maximum specified compression ratio by the machining of the deck surface. 5. To completely plug the holes resulting from the removal of EGR valves and air nozzles. The plugs must
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serve no other purpose. 6. To completely plug the stock fuel injection ports in the cylinder head, if the stock fuel injection is removed and carburetors are utilized. The plugs must serve no other purpose. 7. To utilize O-rings to replace or supplement a cylinder head gasket. 8. To fit valve seats. Valve seats are unrestricted. Valve seat angles are unrestricted. The valve seat insert can be no taller than one half inch. "e. Cylinder Head 1. The cylinder head may be modified to allow installation of permitted alternate components, provided the modification serves no other purpose. 2. Valve seats and valve seat angles are unrestricted. The valve seat may be no taller that one half inch. 3. The cylinder head deck surface may be machined to achieve the specified compression ratio and to allow the installation of o-rings to replace or supplement the cylinder head gasket. 4. Holes resulting from the removal of EGR valves, air nozzles and fuel injectors (if the stock fuel injection system is removed and carburetors substituted) may be plugged, provided the plugs serve no other purpose. 5. Cylinder head ports may be matched to the intake manifold to a depth of no more than 1 inch from the port mating surface."
Request bodywork for Austin Healey Bugeye Sprite MK1
wordingFP and HP Austin-Healey Sprite Mk I and MG Midget variants may replace rear bodywork aft of cockpit with stock-appearing alternate material components.
As printed in Fastrack
In FP, Austin-Healey Sprite Mk I, II, III, IV / MG Midget Mk I, II, III, IV, & 1500, add to the notes as follows: "Sprite Mk I only may replace exterior rear body work, aft of the cockpit and rearmost door opening, with stock appearing components of an alternate material." In HP, Austin-Healey Sprite Mk I, II, III, IV / MG Midget Mk I, II, III, IV, Prep 1, 948cc, add to the notes as follows: "Sprite Mk I only may replace exterior rear body work, aft of the cockpit and rearmost door opening, with stock appearing components of an alternate material." In HP, Austin-Healey Sprite Mk I, II, III, IV / MG Midget Mk I, II, III, IV, & 1500, Prep 1/2, 1275cc, add to
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the notes as follows: "Sprite Mk I only may replace exterior rear body work, aft of the cockpit and rearmost door opening, with stock appearing components of an alternate material." In HP, Austin-Healey Sprite Mk I, II, III, IV / MG Midget (ALL), Prep 2, 1275cc, add to the notes as follows: "Sprite Mk I only may replace exterior rear body work, aft of the cockpit and rearmost door opening, with stock appearing components of an alternate material." In HP, Austin-Healey Sprite Mk I, II, III, IV / MG Midget (ALL), Prep 2, 1098cc, add to the notes as follows: "Sprite Mk I only may replace exterior rear body work, aft of the cockpit and rearmost door opening, with stock appearing components of an alternate material." In HP, Austin-Healey Sprite Mk I, II, III, IV / MG Midget Mk I, II, III, IV, & 1500, Prep1, 1098cc, add to the notes as follows: "Sprite Mk I only may replace exterior rear body work, aft of the cockpit and rearmost door opening, with stock appearing components of an alternate material."
wordingProduction carb rules clarified: carburetor options, fuel injection throttle body dimensions, and intake manifold restrictions reorganised and refined.
As printed in Fastrack
In Production, GCR section 9.1.5.E.1.b., make changes as follows: 9.1.5.E.1.b – Drive Train Level 1, Induction System “1. All inducted air must pass through the venturi(s) of the car’s carburetor(s). Carburetor jets, jet needles, metering rods and needle valves are unrestricted. Choke mechanisms, plates, rods, and actuating cables, wires, or hoses can be removed. The number of carburetors must not be changed from stock, unless otherwise specified by the vehicles spec line. All single carbureted cars may fit a permitted optional carburetor. On cars w Where the use of one (1) 40 DCN, DCNF, IDF carburetor is required specified, a permitted optional carburetor may be substituted. Permitted optional carburetors are: can fit
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one (1) of the following permitted optional carburetors: 1. Weber 32 DGV/DGAV/DGEV 2. Weber 32/36 DGV/DGAV/DGEV 3. Weber 32/36 DFV/DFAV/DFEV 4. Weber 34 DAT/DATR/DATRA/DMTR 5. Holley-Weber 5200. Carburetor jets, jet needles, metering rods and needle valves are unrestricted. Choke mechanisms, plates, rods, and actuating cables, wires, or hoses can be removed. Where Weber carburetors are specified, Weber type carburetors can be substituted. The following are p Permitted Weber type carburetors are:
A specification table follows in the original; it is not shown here.
wordingEP, FP, HP carburetors clarified: jets, needles, metering rods, needle valves unrestricted; choke parts removable; permitted optional carburetors listed.
As printed in Fastrack
In Production GCR section 9.1.5.E.2.b.1., make changes as follows: 9.1.5.E.2.b.1., – Drive Train Level 2, Induction System “All inducted air must pass through the venturi(s) of the car’s carburetor(s). Carburetor jets, jet needles, metering rods and needle valves are unrestricted. Choke mechanisms, plates, rods, and actuating cables, wires, or hoses can be removed. The number of carburetors must not be changed from stock, unless otherwise specified by the vehicles spec line. All single carbureted cars may fit a permitted optional carburetor. Where the use of one (1) 40 DCN, DCNF, IDF carburetor is specified, a permitted optional carburetor may be substituted. Permitted optional carburetors are:
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1. Weber 32 DGV/DGAV/DGEV 2. Weber 32/36 DGV/DGAV/DGEV 3. Weber 32/36 DFV/DFAV/DFEV 4. Weber 34 DAT/DATR/DATRA/DMTR 5. Holley-Weber 5200. The stock or permitted alternate carburetor must not be modified. Carburetor jets, jet needles, metering rods and needle valves are unrestricted. Choke mechanisms, plates, rods, and actuating cables, wires, or hoses can be removed. The number of carburetors must not be changed from stock. Where Weber carburetors are specified, a permitted Weber type carburetor can be substituted. Permitted Weber type carburetors are:
A specification table follows in the original; it is not shown here.
fasterEP, FP, HP clarified: tapered holes in ball joints now allowed for bolt conversion; wheel bearings and hubs unrestricted at any wheel.
As printed in Fastrack
Note from CRB: 9.1.5.E.5.b.2 in “Suspension and Steering Level 2: Suspension Components” states that “Suspension control arms, bushings, bearings, and ball joints are unrestricted.” However, allowance to ream out ANY tapered hole from a stock ball joint does not exist, unless being done to a specifically unrestricted component, like a suspension control arm. This is not the intent to restrict in that manner, and should be clarified: In GCR section 9.1.5.E.5.b.2, add wording as follows: “Suspension bushings, bearings, and ball joints are unrestricted. Tapered holes can be drilled or reamed, to allow a bolt to be used in place of a ball joint.”
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Note from CRB 9.1.5.E.2.o.5 in “Final Drive” states that “Axle shafts, bearings, bearing carriers, hubs, and universal joints/CV joints are unrestricted.” Therefore any of those items, all of which are defined in the GCR, that are part of the final drivetrain system of the vehicle, are indeed unrestricted. However, this rule would not apply to a non-driven axle, as it is not part of the drivetrain. It is agreed that allowing unrestricted bearings and hubs should not be limited to only the driven axle, and it should be applied to both axles/at any wheel: In GCR section 9.1.5.E.5.b. add wording as follows: “6. Wheel bearings and hubs are unrestricted.”
wordingEP open cars may now use aftermarket hardtops if they retain OEM appearance; specific model hardtop allowances removed.
As printed in Fastrack
In GCR section 9.1.5.E.9.a.12, remove wording as follows: “Open cars must remove convertible soft tops, and attaching bracketry and fasteners. Open cars retaining the stock windshield may retain the stock removable hardtop if attached to the car by positive fasteners. Open cars must remove convertible soft tops and all attaching bracketry and hardware. If the stock windshield is retained, OEM and aftermarket hardtops are allowed. Aftermarket hardtops must retain OEM appearance in all exterior profiles, and carbon fiber construction is not allowed. Any hardtop must be attached by positive fasteners.” In EP, remove wording from spec line notes as follows:
In HP, Toyota Yaris (06-11), Toyota Yaris Sedan (07-12), Toyota Yaris (12-18), add weight to the spec line as follows: “1970 2100 *2019 2153 **2069 2205”
Request to Allow 2011+ Fiesta to Change Bolt Pattern on Wheels
wordingHP Ford Fiesta years corrected to 11-16; Mazda hubs D651-33-06 front and D651-26-15XE rear allowed.
As printed in Fastrack
In HP, Ford Fiesta (11-15), add to the notes and correct the years in the spec line as follows: “Mazda front hub D651-33-06 and rear hub D651-26-15XE allowed.” “(11-15 16)” first page of the spec line “(12-13 11-16)” second page of the spec line
Other letters
Clean-up to Standardize L1 & L2 Rules
#40891 from Production Committee · Recommended to the Board · Minutes (2026-10 Fastrack)
In GCR, Section 9.1.5.E.1.o.5., change as follows: "Axle shafts, bearings, bearing carriers, hubs, and universal joints/CV joints, and differential covers are unrestricted." In GCR, Section 9.1.5.E.1.m.6. change as follows: "Engine mounts of alternate design and/or material can be used, but there can be no change to the engine’s fore, aft or vertical location except as permitted in 9.1.5.E.1.o.6 7. Engine mounts must attach to the engine in their stock location." In GCR, Section 9.1.5.E.1.n.1. change as follows: "The Transmission and its mount(s) areis unrestricted, providing that it is fit in the same basic location as stock. Sequential shifting transmissions are prohibited. Pneumatic, hydraulic or electric actuation of the gear shift mechanism is prohibited."
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In GCR, Section 9.1.5.E.1.o.6. change as follows: "Transverse engine cars can rotate the engine about the crankshaft centerline to align axle shafts/constant velocity joints. On rear engine/rear drive cars the engine/drivetrain can be relocated vertically upward, to a maximum of one inch, to allow alignment of suspension and driveline components. Differential mounts are unrestricted, provided the differential remains in the stock location except as permitted in 9.1.5.E.1.o.7." In GCR, create section 9.1.5.E.1.o.7. as follows: "Transverse engine cars can rotate the engine about the crankshaft centerline to align axle shafts/constant velocity joints. On rear engine/rear drive cars the engine/drivetrain can be relocated vertically upward, to a maximum of one inch, to allow alignment of suspension and driveline components."
After much investigation and discussion into these items, and reflection upon the proceedings that brought them to light, it was determined that a wide variety of vehicles throughout the Production Category have modifications to diff covers, diff mounts, and trans mounts that could potentially be ruled illegal to the rules as they were written. Therefore, the rules addressing these items were heavily scrutinized for both clarity and intent, which then drove the decision to make the changes as published. It is believed that these revisions both clean up multiple "grey areas" and are within reason of the Prep. Level 2 ruleset. The Prod Committee understands that the timing and the optics of the situation are poor, but this doesn't affect the determination that changes to these rules to more accurately represent intent was needed.
Thank you for your request, but it is not recommended. Rules already exist that allow all carbureted cars to adapt a fuel injected throttle body in place of its carb(s), with the same "choke" size. Permitting whole alternate fuel injection systems that were not offered stock on a spec line is not something that is currently being considered.
Allow Unrestricted Mounting of Differential and Transmission
In GCR, Section 9.1.5.E.2.m.6. change as follows: "Engine mounts of alternate design and/or material can be used, but there can be no change to the engine’s fore, aft or vertical location except as permitted in 9.1.5.E.1.o.6 2.o.7. Engine mounts must attach to the engine in their stock location." In GCR, Section 9.1.5.E.2.n.1. change as follows: "The Transmission and its mount(s) areis unrestricted, providing that it is fit in the same basic location as stock. Sequential shifting transmissions are prohibited. Pneumatic, hydraulic or electric actuation of the gear shift mechanism is prohibited." In GCR, Section 9.1.5.E.2.o.6. change as follows: "Transverse engine cars can rotate the engine about the crankshaft centerline to align axle shafts/constant velocity joints. On
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rear engine/rear drive cars the engine/drivetrain can be relocated vertically upward, to a maximum of one inch, to allow alignment of suspension and driveline components. Differential mounts are unrestricted, provided the differential remains in the stock location except as permitted in 9.1.5.E.2.o.7." In GCR, create section 9.1.5.E.2.o.7. as follows: "Transverse engine cars can rotate the engine about the crankshaft centerline to align axle shafts/constant velocity joints. On rear engine/rear drive cars the engine/drivetrain can be relocated vertically upward, to a maximum of one inch, to allow alignment of suspension and driveline components."
Make it Clear that Differential Covers are Unrestricted
In GCR, Section 9.1.5.E.2.o.5., change as follows: "Axle shafts, bearings, bearing carriers, hubs, and universal joints/CV joints, and differential covers are unrestricted."
Dual 1.5 inch SUs (Unmodified) for 1296 Spitfire in HP
This request is not recommended. The Midget and the Spitfire have fundamentally different engines and therefore classification changes associated with one does not automatically qualify the other to receive the same. The 1296cc Spitfire has shown good performance potential as-is, and the ability and balance of both will continue to be monitored.
Allowing a 5-speed transmission for a spec line where only a 4-speed transmission came originally, is not consistent with class philosophy. Therefore, this letter is not recommended.
In section 9.1.5.E.11, make the following modification: "Glass headlight, front parking, side marker and signal light components must be removed. Plastic headlight, front parking, side marker and signal light components can be removed. The headlight bezels/rims must remain in their stock locations but can be replaced by components of an alternate material, provided their appearance remains stock. If the stock headlight, front parking, side marker or signal light lenses/covers are removed the resulting openings must be covered with wire mesh screen or solid panels of the same or a flatter contour than the stock lenses/covers. The openings created by the removal of these items must be covered with screens or panels. These covers must be the same or flatter contour as the stock lenses/covers, and may be attached to or integrated into surrounding bodywork. Headlight bezels/rims must remain in their stock locations but can be
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replaced by components of an alternate material, provided their appearance remains stock." In section 9.1.5.E.11.A, make the following modification: "Retractable or “pop up” headlight assemblies can be run in their open, partially opened, closed position or removed in their entirety. The openings created by the removal of the assembly must be covered with screens or panels. These covers must be the same or flatter contour as the stock assembly in its closed position, and may be attached to or integrated into surrounding bodywork, but need not retain any bezels/rims."
Availability of rebuilt brake calipers and caliper rebuild kits for these cars doesn’t appear to be a major issue when expanding source options beyond RockAuto. Additionally, the current aftermarket brake allowance is specifically for addressing concerns with performance, durability, and parts availability of stock brake components.
This request is not recommended at this time. The letter writer is encouraged to develop to the current specs to fully understand this classifications potential.
Revisions to Transmission Rules Consistent with Spec Line Format
In GCR, Section 9.1.5.E.1.n., change as follows: "5. The "Trans. Speeds" number of transmission speeds l isted in a car’s specification line indicates the maximum is the number of forward gears that may be operable by the driver from the normal seated position (e.g. a 6 speed transmission with 1 forward gear removed/disabled is considered a 5 speed transmission). 6. The "Trans. Speeds" number listed in a car’s specification line indicates the maximum number of forward gears that may be operable by the driver from the normal seated position (e.g. a 6 speed transmission with 1 forward gear removed/disabled is considered a 5 speed transmission)."
We appreciate your perspective and feedback. Please see response to Letter #39223, as it effects this vehicle. The impact of this new change will be monitored before anything additional with be considered, therefore this request is Not Recommended at this time.
Rescind the 50lb weight penalty added to 84-87 Honda Civic/CRX
We appreciate your perspective and feedback. Please see response to Letter #39223, as it effects this vehicle. The impact of this new change will be monitored before anything additional with be considered, therefore this request is Not Recommended at this time.
We appreciate your perspective and feedback. After thorough consideration of the survey responses, input from our tire manufacturers, the current state of wheel size variation and competition balance within each class, potential performance benefits that could be realized by the proposed changes, the ever-increasing costs of racing, and the current environment of Road Racing in general, the PAC has come to the conclusion to NOT make any large, sweeping changes to the current wheel specs at this time. It is evident that this is a sensitive and polarizing subject with no clear answer to what the best direction is for the Production Category, and that is ultimately why this decision is being made. Note that instances where a discrepancy appears to exist versus typical max wheel spec practices may still be considered for adjustment. The PAC wishes to thank all survey participants, as their responses did highlight how varied the opinions are on this subject, as well
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as any other input that was provided to help make this decision.
Thank you for your letter and bringing up this idea. The Prod Advisory Committee would have no problem with considering such a circumstance on a case-by-case basis, but don't see a need or a path forward for creating a sweeping allowance in the Production Ruleset for such a thing. Again though, if someone wanted to make a request to classify a specific turbocharged vehicle into the Production category, but without the turbocharger, that is a discussion that would certainly be had and studied for feasibility.
Thank you for your letter, but this is not recommended currently. Multiple rule changes have occurred in recent years in an attempt to help this classification, by permitting both fuel injection and 12.0:1 compression, and to date no example has been prepped to fully exploit both of these allowanced and then brought out and raced. It is not reasonable to now consider a weight break as well, in addition to these prior changes, when the impact of those changes is still not fully known.
In GCR, Section 9.1.5.E.9.a.11., change as follows: "(Effective 6/1/2025) Glass headlight, front parking, side marker and signal light components must be removed. Plastic headlight, front parking, side marker and signal light components can be removed. The headlight bezels/rims must remain in their stock locations but can be replaced by components of an alternate material, provided their appearance remains stock. If the stock headlight, front parking, side marker or signal light lenses/covers are removed the resulting openings must be covered with wire mesh screen or solid panels of the same or a flatter contour than the stock lenses/covers."
Thank you for your letter, but this requested allowance is not recommended at this time. Several other changes were recently made within HP in an effort to improve the competitive balance, and the results of those changes would like to be monitored. Please continue your efforts to develop and campaign this spec line, so it's performance can also continue to be reviewed against the other vehicles in the class.
The differences in the intake manifold, throttle body, and injectors (both placement and quantity) between the '88-91 CRX DX and Si model's are significant, and a majority of the reasoning for why one is in HP and the other is in FP. Allowing the HP '88-91 CRX DX to run the FP '88-91 CRX Si's IM, TB, & injectors would not only be outside of class philosophy, but it would also result in a significant performance gain for a spec line that is proven to be competitive in HP. This allowance is not recommended.
Thank you for your letter, but changes for this car are not recommended at this time. Collected data indicates that it is very close to the ideal performance realm of HP, and other changes are being made at this time to try and further improve balance within the class.
Thank you for your letter, however additional changes for this car are not recommended at this time. The PAC would like to see more usage of the 12.0:1 compression allowance that was given for the 2024 season, so that additional data of its impact can be gathered, as well as the effect of other changes that are being made within the HP class.
Please Accommodate a Modern Tire Option, 100TW, 200TW
Thank you for your letter, but this is not recommended. Competitors are already allowed to run whatever tire they choose in the Production Category provided it is fitted to a permitted wheel per their spec line. There is zero intention or desire to begin making special weight/competition balance allowances for whatever different tires a competitor may choose to run.
Consolation of GTL and FP; Under 1300cc GTL cars to HP
Thank you for your thoughtful letter however for now there will be no changes until data is collected on the cars that have been impacted by the new rules and specifications.
Thank you for your letter. A Wheel & Tire Survey is being sent out in early September to gather feedback from Production racers on if/how the wheel and tire sizes in the Production Category should be standardized. The results of this survey and any resulting actions that comes from it would like to be realized before any specific vehicle wheel limitations are considered. Please look for this upcoming survey and provide feedback accordingly to your desires.
Thank you for your letter. The Wheel & Tire Survey is currently in the final stages of development and approval. It should be sent out in early September prior to the Runoffs.
Thank you for your letter, but this request is not recommended. Permitting an alternate intake manifold on a Prep Level 2 specification is against class philosophy, and it is not believed that the safety concern that is presented with the stock intake manifold design is valid. It is not uncommon for a throttle body to be located on the same side of the engine as its exhaust manifold and/or fuel lines. Additionally, within the existing rules, intakes (ahead of the throttle body) are unrestricted, so any piping can be shielded/insulated from heat, and fuel lines can be replaced with braided stainless steel lines, so alternate methods do exist within the current rules to address these perceived issues.
Thank you for your letter. The recent allowance for carbureted cars to install fuel injection systems only permitted an alternate method of delivering the same amount of air/fuel, through the same venturi/restrictor size, as parts for older carburetors are becoming increasingly harder to source, while aftermarket fuel injection systems are becoming cheaper and more readily available. Asking for completely alternate transmissions, which increase the number of forward gears, as a performance benefit, is not viewed as comparable.
Clarification of Rule 9.3.26 Fuel Cell Specifications
Thank you for your letter. Without knowing your specific car, as long as it fits the statement of requirements of the first sentence of 9.3.26 your interpretation is correct.
Thank you for your letter, but this change is not recommended. The effect of the recent compression increase that was given to these cars needs to be fully realized before any additional changes will be made to their classifications. Additionally, it should be stated that the carb modification that's being discussed here is against the core of the Limited Prep Prod philosophy.
Thank you for your letter, but allowing a higher quantity of gears beyond what a car came with originally, is not within class philosophy. If the competitive balance of a particular car is in question, then a suggestion should be made for an adjustment that's within the usual philosophy of the Production category.
Thank you for your letter, but no further adjustments are going to be considered for this classification at this time. The effects of recently made changes need to be fully realized first.
Please change the end year for letter #35426 to be 2010.
Thank you for your letter, but this addition is not recommended. The '06-'10 Beetle came with a 2.5L engine, larger brakes, and other cosmetic changes, all of which make it a different car than the '98-'05 and push it beyond the performance scope of HP. It is also not a feasible to specify or restrict which parts from which years of a production run can be used within a spec line. Please note that it is already legal to use identical parts to those that were fitted as Original Equipment even if they were pulled from a car that's not within the model/trim/year limitations of the spec line.
Thank you for your letter. Letter writer was contacted, the topic was discussed, and he understands that the "Track" on a spec line is a MAX value. The configuration he's wanting to run is already legal per the existing rules and Spitfire classifications.
Thank you for your letter but the performance potential of the Neon, with either the SOHC or DOHC engine, does not fit within HP. All of the current HP classifications with 2.0L SOHC engines utilize only 8-valves with restrictive head and intake manifold designs. This is not the case with the Neon which uses modern cross-flow heads with 16-valves, an intake manifold with individual runners, and multi-port fuel injection. These cars (Neon SOHC & DOHC) need to show their potential in FP when actually built to the limits of the Production rules before adjustments to their classifications will be considered.
Thank you for your letter; this change is not recommended. If there's a desire to run the 1.8L crank then Mr. LaManna should consider using the 1.8L engine which is also classified as an option in HP in this chassis and is a well-known, competitive option. As for the weight of the VW (1.7L and 1.6L) the Committee finds it to be appropriate at this time. It is understood that these engines will not have the top-end speed of the 1.8L, but they are also classified at a substantially lighter weight providing other performance attributes. Upon further request by Mr. LaManna (to be submitted through the letter system) the PAC would be open to collecting data on his car during the 2024 season.
Thank you for your letter. This change is not recommended as no additional reasoning has been provided, or data collected, since the last time this was considered. The fact that one classification received an adjustment does not provide justification for adjustment for another.
Look Over the Performance of the VW's and Adjust as Necessary
Thank you for your letter. There is not sufficient evidence to determine that the HP 1.8L VW needs any adjustment at this time. Other changes are also being made within HP that should affect the total competition balance of the class. The need for additional adjustments will continue to be monitored.
Thank you for your letter. An adjustment has been made to the HP 1275cc Sprite/Midget, with "Level 1/2" preparation, in the response to letter #35138 in current Fastrack. No other adjustment will be considered at this time.
Thank you for your letter. An adjustment has been made to the HP 1275cc Sprite/Midget, with "Level 1/2" preparation, in the response to letter #35138 in current Fastrack. No other adjustment will be considered at this time.
BOP adjustments for Austin Healey / MG / BLMI LP1275
Thank you for your letter. An adjustment has been made to the HP 1275cc Sprite/Midget, with "Level 1/2" preparation, in the response to letter #35138 in current Fastrack. No other adjustment will be considered at this time.
Thank you for your letter. An adjustment has been made to the HP 1275cc Sprite/Midget, with "Level 1/2" preparation, in the response to letter #35138 in current Fastrack. No other adjustment will be considered at this time.
Thank you for your letter. An adjustment has been made to the HP 1275cc Sprite/Midget, with "Level 1/2" preparation, in the response to letter #35138 in current Fastrack. No other adjustment will be considered at this time.
Thank you for your letter. An adjustment has been made to the HP 1275cc Sprite/Midget, with "Level 1/2" preparation, in the response to letter #35138 in current Fastrack. No other adjustment will be considered at this time.
Thank you for your letter. An adjustment has been made to the HP 1275cc Sprite/Midget, with "Level 1/2" preparation, in the response to letter #35138 in current Fastrack. No other adjustment will be considered at this time.
Thank you for your letter. An adjustment has been made to the HP 1275cc Sprite/Midget, with "Level 1/2" preparation, in the response to letter #35138 in current Fastrack. No other adjustment will be considered at this time.
Thank you for your letter. An adjustment has been made to the HP 1275cc Sprite/Midget, with "Level 1/2" preparation, in the response to letter #35138 in current Fastrack. No other adjustment will be considered at this time.
MILLER) Addition Induction Capacity for the British Leyland 1275cc
Thank you for your letter. An adjustment has been made to the HP 1275cc Sprite/Midget, with "Level 1/2" preparation, in the response to letter #35138 in current Fastrack. No other adjustment will be considered at this time.
In GCR, Section 9.1.5.E.1.b.2., change as follows: "Stock or permitted alternate sidedraft carburetor(s) can use an adaptor plate and/or a spacer in addition to any stock spacer, between the carburetor(s) and the intake manifold. Material for the adaptor plate and spacer is unrestricted. No adaptor plate or spacer can serve any purpose other than to space out and/or mate the carburetor(s) to the permitted intake manifold. The adapter or spacer cannot create a plenum or change the carburetor(s) orientation. The maximum thickness for the adapter, spacer, stock spacer or combination of all is 1.25”. For the purpose of these rules an Isolator is a spacer. Classifications that have no fuel injection allowance on their spec line may substitute a fuel injected throttle body in place of each of its permitted carb(s). This alternate throttle body must have a Choke with the same diameter of the approved carb(s). A Flat Plate Intake
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Restrictor matching the specified choke dimension may also be used. The fuel injector(s) must be part of the throttle body." In GCR, Section 9.1.5.E.1.b.3., change as follows: "Stock or permitted alternate downdraft carburetor(s) can use an adaptor plate and/or a spacer in addition to any stock spacer, between the carburetor(s) and the intake manifold. Material for the adaptor plate and spacer is unrestricted. No adaptor plate or spacer can serve any purpose other than to space out, or mate the carburetor(s) to the permitted intake manifold. The adapter or spacer cannot change the carburetor(s) orientation. Adaptors and spacers can have a bore larger than the throttle bore of the stock or permitted alternate carburetor(s). The maximum thickness for the adapter, spacer, stock spacer or combination of all is 1.25”. For the purpose of these rules an Isolator is a spacer. Stock carb(s), permitted alternate side-draft carb(s), permitted alternate downdraft carb(s), and permitted alternate fuel injected throttle bodies can use an adaptor plate/spacer to mount to the permitted intake manifold, in addition to any stock spacer. Material for the adaptor plate/spacer is unrestricted. No adaptor plate/spacer can serve any purpose other than to space out and/or mate to the permitted intake manifold. The adapter plate/spacer cannot create a plenum or change the orientation of the mounting. The bore diameter of the adaptor plate/spacer is unrestricted. The maximum thickness for the adapter plate/spacer and any stock spacer (if used) is 1.25”. For the purpose of these rules an Isolator is a Spacer." In GCR, Section 9.1.5.E.2.b.2., change as follows: "Stock or permitted alternate sidedraft carburetor(s) can use an adaptor plate and/or a spacer in addition to any stock spacer, between the carburetor(s) and the intake manifold. Material for the adaptor plate and spacer is unrestricted. No adaptor plate or spacer can serve any purpose other than to space out and/or mate the carburetor(s) to the permitted intake manifold. The adapter or spacer cannot create a plenum or change the carburetor(s) orientation. The maximum thickness for the adapter, spacer, stock spacer or combination of all is 1.25”. For the purpose of these rules an Isolator is a spacer. Classifications that have no fuel injection allowance on their spec line may substitute a fuel injected throttle body in place of each of its permitted carb(s). This alternate throttle body must have a Choke with the same diameter of the approved carb(s). A Flat Plate Intake Restrictor matching the specified choke dimension may also be used. The fuel injector(s) must be part of the throttle body." In GCR, Section 9.1.5.E.2.b.3., change as follows: "Stock or permitted alternate downdraft carburetor(s) can use an adaptor plate and/or a spacer in addition to any stock spacer, between the carburetor(s) and the intake manifold. Material for the adaptor plate and spacer is unrestricted. No adaptor plate or spacer can serve any purpose other than to space out, or mate the carburetor(s) to the permitted intake manifold. The adapter or spacer cannot change the carburetor(s) orientation. Adaptors and spacers can have a bore larger than the throttle bore of the stock or permitted alternate carburetor(s). The maximum thickness for the adapter, spacer, stock spacer or combination of all is 1.25”. For the purpose of these rules an Isolator is a spacer. Stock carb(s), permitted alternate side-draft carb(s), permitted alternate downdraft carb(s), and permitted alternate fuel injected throttle bodies can use an adaptor plate/spacer to mount to the permitted intake manifold, in addition to any stock spacer. Material for the adaptor plate/spacer is unrestricted. No adaptor plate/spacer can serve any purpose other than to space out and/or mate to the permitted intake manifold. The adapter plate/spacer cannot create a plenum or change the orientation of the mounting. The bore diameter of the adaptor plate/spacer is unrestricted. The maximum thickness for the adapter plate/spacer and any stock spacer (if used) is 1.25”. For the purpose of these rules an Isolator is a Spacer."
Thank you for your letter. No changes are being proposed to GCR Section 9.3.26 "Fuel Cell Specification" that will affect Production cars. Per that section, any Production classified vehicle can run a stock fuel tank, provided "the stock fuel tank is located between the axle center lines and within the main chassis structure (i.e., frame rails, etc.)", or is otherwise allowed on its spec line.
Thank you for your letter. It is against class philosophy to allow an engine that never came in a specific chassis. Also note that historically, the VW 1.6L engine has raced successfully and reliably in both Full Prep and Limited Prep build levels.
Thank you for your letter. Please see response to Letter #34010 in current Fastrack.
Remove 9.1.5.E.8.c
#34010 from Production Committee · Recommended to the Board · Minutes (2023-06 Fastrack)
In Production, Section, 9.1.5.E.8.c. remove as follows: "(Effective 01-01-2024) Cars using 13” wheels may run 8 inch wide (max) wheels, but only with Race Tires America American Racer 20.0-8.0-13, bias ply, non-belted tire. Cars using 15” wheels may run 10 inch wide (max) wheels, but only with Race Tires America American Racer 23.5-10.0-15, bias ply, non-belted tire."
Clarification of Production Category Specification 9.1.5.E.9.a.18
9.1.5.E.9.a.18 says the following: "Stock or aftermarket rear spoiler or wing not permitted, unless factory installed for the listed base model or permitted on the car’s spec line." Typically, the "base model" of a vehicle is considered the cheapest variant that was offered by the manufacturer of a particular model, with the least amount of features. The rule specifies that the only rear spoiler or wing that may be fitted is the version that came from the factory installed on the most basic model of a vehicle that fits within its spec line. The vehicle in question is the HP "Ford Fiesta (11-16)". If multiple trim levels of the Ford Fiesta from '11-16 fit within all of the parameters of that spec line (engine, trans, brake, dimensions, etc.), then only the spoiler/wing that was fitted to the most basic of those trim levels would be legal. If that same spoiler/wing is also fitted to higher trim levels, that is redundant information. Also note that if the
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most basic trim level did not come from the factory with an installed spoiler/wing, then none would be permitted. An optional or dealer installed spoiler/wing would also not be permitted.
In Production Category Specifications, GCR Section 9.1.5.E.2.f.1., change as follows: "Camshafts are unrestricted. Any lifters, tappets/cam followers of the same type and diameter as stock are permitted. The interchange of hydraulic and solid lifters is permitted. (Effective 1/1/2024)" In Production Category Specifications, GCR Section 9.1.5.E.2.f.5., change as follows: "Pushrods are unrestricted. Rocker shafts and/or shaft pedestals, when utilized in the stock type system, can be replaced by alternate shafts and/or pedestals and are unrestricted. Valve rocker arms and/or rocker type cam followers are unrestricted, but the rocker ratios and/or follower ratios must be stock. (Effective 1/1/2024)"
Remove 9.1.5.E.8.c
#34010 from Production Committee · Member feedback requested · Minutes (2023-04 Fastrack)
The Production Advisory Committee is seeking member input regarding the possibility of removing rule 9.1.5.E.8.c: "9.1.5.E.8.c - Cars using 13” wheels may run 8 inch wide (max) wheels, but only with Race Tires America American Racer 20.0- 8.0-13, bias ply, non-belted tire. Cars using 15” wheels may run 10 inch wide (max) wheels, but only with Race Tires America American Racer 23.5-10.0-15, bias ply, non-belted tire." The original intent of this rule was to provide a second viable racing tire option to the Production Category when Goodyear stopped production of its bias-ply tires several years ago. At the time, Race Tires America made promises to supply their American Racer asphalt tire in appropriate sizes and road-racing compounds for use in Prod, but was not willing to say that it could be used on a 7" wide tire, which most 13" and 15" wheel applications in Production are limited to. Therefore this
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allowance was made, with the anticipation that Race Tires America would support it, it would become a viable option in the category, and racers would take up this option. Since then, the following has happened: - Goodyear has returned to making bias-ply slick tires, as well as a radial slick tire, for Prod competitors. - The American Racer tire is only produced in the softest compound that Race Tires America offers, which is not intended or viable for the longer circuit-racing events that the SCCA competes in. - The existence of this rule has been used to argue that even further special tire & wheel package allowances should be made, creating confusion regarding the direction and intent of the tire & wheel rules within the Prod category. As of this writing, it is not believed that any current Production racer is actively utilizing this rule, in order to run this tire & wheel package. If there is, and they would like to see this rule continue as-is, please let us know.
Please Revisit Tire and Wheel Width Rule Letter #33728
Thank you for your letter. There is no change to the original response to letter #33728, which requested that vehicles which are specified to run a MAX 13" diameter wheel be allowed to run a 15x7" wheel when using the B-Spec Hankook or SM Hoosier tire. It pointed at rule 9.1.5.E.8.c as justification to why this should be allowed. Rule 9.1.5.E.8.c allows for an increase in wheel WIDTH only, when running a specific America Racer tire. It does not allow for an increase in wheel diameter, versus what is on a vehicles spec line, which is not the same as what's being requested here. Furthermore, its existence alone is not enough of a justifiable reason for the PAC to make further special tire and wheel package allowances, which are outside the scope of the Production Category. If the goal is to just find a cheaper alternative than the radial or bias-ply slick tires that are common in Prod, with competitiveness not being a concern, then a competitor is free to use a DOT race or street tire that fits their MAX
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wheel size, as specified on their vehicles spec line.
Thank you for your letter, but this allowance is not recommended. It is not within class philosophy to make specific tire and wheel package allowances outside of what's on a vehicles spec line, especially if the goal of that package is to be NOT competitive, and then require monitoring to ensure that this is the case. Note that any tire is already legal to run in the Prod category, but the max wheel size limitation on a vehicles spec line must be adhered to.
Headlight and Marker Light Covers, Mounting, and Gaps
Thank you for your letter. It is believed that the rules are adequate as written. It is ultimately the competitor’s responsibility to adhere to them in an appropriate and reasonable manner, and be able to defend the modifications they have made to their car versus the rulebook. It is clearly defined what lights can/must be removed, that the resulting holes left after the removal of these lights must be covered with a screen/panel, and how that screen/panel can be contoured. A reasonable interpretation would be to ensure that the screen/panel closely replicates the shape and location of the light(s) it is replacing, and that the stock shape and profile of the vehicle remains intact. But again, it is ultimately the competitors responsibility to defend the legality of their car versus the rules and how they are written.
Thank you for your letter. Your letter concerning performance of the 70-74 Corolla has been reviewed, but an adjustment cannot be deemed appropriate at this time, without any new information to consider. The Committee requests that 70-74 Corolla racers participate in events, so that this request can be reconsidered with additional on-track performance observed and possible in-vehicle data collected. Please note that thirty (30) days advance notice of participation will help in the coordination necessary to install data boxes.
Thank you for your letter. The need for a positive performance adjustment for the L2 AH/MG/BLMI 1275cc engines has been reviewed, and it is not recommended at this time, as these classifications continue to be competitive at a variety of tracks. It is well understood that the wide variety of different classifications that exist within a Production class will achieve their lap times in different ways, especially across a variety of track styles. If the desire is to just change how these classifications "race" against their competition, and not necessarily their performance potential, then it would be reasonable to assume that any additional horsepower and straight-line ability would come at the expense of an off-setting weight increase. This has not been done before for a LP classification, as the net result is forcing its racers to build new engines with higher compression and lower reliability, and carry around more weight that will further wear
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on consumables, in order to net the same performance potential. The Committee simply does not feel that this is an appropriate measure to ask racers to endure, for the sake of hoping to change how their car produces a lap time.
Allow B-Spec cars to run in Prod & align with 9.1.5.B.5
#33596 from Production Committee · Recommended to the Board · Minutes (2023-01 Fastrack)
In GCR, Production Category, Section 9.1.5.B.5. change as follows: “Any Improved Touring car meeting all the requirements of ITCS 9.1.3 may compete in the Production class in which the same make, model and engine displacement car is classified. For Improved Touring cars competing in Production, the level of preparation and modifications will be as determined by ITCS 9.1.3 and not by PCS 9.1.5, including tire limitations as defined in 9.1.3.D.8.a.2. however any DOT approved tire as defined by 9.3.45 is allowed. This is intended to allow Improved Touring competitors to become more familiar with Production to assist them in determining whether to modify their cars to meet the requirements of PCS 9.1.5 and also to permit Improved Touring competitors to compete in all events open to Production cars.” In GCR, Production Category, Section 9.1.5.B. add the following:
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"6. Any B-Spec car meeting all the requirements of BSCS 9.1.10 may compete in the Production class in which the same make, model and engine displacement car is classified. For B-Spec cars competing in Production, the level of preparation and modifications will be as determined by BSCS 9.1.10 and not by PCS 9.1.5, including tire limitations as defined by 9.1.10.E.7."
Thank you for your letter. A competition adjustment for this car is not recommended at this time. Trap speed data has shown that it is quite reasonable for a variety of tracks, plus track sector data has also shown that it has competitive dynamic prospect as well.
Thank you for your letter. The Porsche 914 has Prep2 classifications in HP with the 1.8L engine and in FP with the 2.0L engine. Neither of these classifications have been attempted, so there is no on-track results or data to include for consideration of adjustments or re-classification. The PAC would like to see these attempted to assist with these considerations, as was the case with the few 2.0L cars that were previously moved from FP to HP.
Thank you for your letter. Adjustments to this vehicle are not recommended at this time. Collected on-vehicle, trap speed, and sector data all shows that the current classification has the potential to be competitive in the class. Since this is a fairly new classification in HP, the PAC would like to see it continue to be developed and campaigned so additional info can be gathered, and its development be monitored.
Thank you for your letter. Rule 9.1.5.E.5.c.5 already states the following: "Suspension pickup/pivot axis points can be reinforced but must remain in the stock location." Adding a shock/strut/tie bar would be considered the reinforcing of stock suspension pickup points, and therefore legal within this rule.
Thank you for your letter. This vehicle has proven to be nationally competitive at its current classification, including multiple Runoffs wins. Any adjustments to it are Not Recommended at this time.
Global MX5 Cup Car Ignores Production Class Philosophy.
Thank you for your letter. The consideration of manifold porting or the use of an alternate non-USDM stock intake manifold for the limited-prep Fiat X1/9's in HP was already considered and responded to via Letter #31602 in the January Fastrack. These cars also received a weight reduction via Letter #31653 in the January Fastrack, and the results of that need to be seen.
Thank you for your letter. An adjustment of this spec line is not recommended at this time. Please continue to develop the car, and an effort will be made to try and get additional data on it.
Thank you for your letter. A response was made to this consideration in the October 2021 Fastrack, via #31071, and there has been no additional reasoning to reconsider.
Consider Disable/Remove Stock Variable Lift/Timing Systems
Thank you for your letter. After inspection of the GCR, it was determined that there's sufficient ability in the current rules for cam shafts, cam gears, rockers, sensors, wiring, and ECU's for stock Variable Lift & Timing systems (VANOS, VTEC, VVT-i, etc.) to be legally disabled or removed within them. This determination is being published as an "FYI".
Thank you for your letter. Moving this Level 1 FP classification down to HP is not recommended. Creating a new Level 2 HP classification for this vehicle could be considered, if requested.
Thank you for your letter. This change is not recommended. Building to the currently specified compression ratio is the responsibility of the engine builder, and it is believed that the car will be competitive as classified, once that is accomplished.
Thank you for your letter. The concerns you bring up are absolutely warranted, but in relation to two new HP classifications that were incorrectly initially published with the wrong carburation specs in the January Preliminary Fastrack (Letter #31665 & #31802). This error was corrected before the final version of the January Fastrack was posted, so the issue has been taken care of, and no further action is needed at this time.
Request for Clarification to Allow Factory Idle Air Control
Thank you for your letter, but this vehicle is not recommended for HP. Its engine is comparable to the other Protege's that are already in FP, and it is believed it would gain too much when built to Prep 2 Prod rules, to fit into HP at a reasonable weight for the class. It could be considered for FP, if requested.
Thank you for your letter. Please see response to letter #31653 in current Fastrack. No other changes to this classification will be made at this time.
Thank you for your letter. Please see response to letter #31653 in current Fastrack. No other changes to these classifications will be made at this time.
Thank you for your letter. This allowance is not recommended. Please note that other adjustments were made to this car in letter #31653 in current Fastrack.
Thank you for your letter, but this is not recommended. Trying to balance the potential of different tires through weight breaks would be a difficult and unrealistic exercise, with constantly moving targets. It would also create an even bigger disparity in how different cars achieve their lap times. Competitors are free to use whatever tires they'd like, but their competitiveness cannot be guaranteed.
Request to move FP Dodge Neon (95-99) SOHC from FP to HP
Thank you for your letter, but this request is not recommended. The Neon engines are modern, 16-valve, cross-flow, over-head- cam engines, unlike the other 2.0L cars that were added to HP earlier in 2021. Its performance capability belongs in FP. Adjustments to the Neon's spec lines in FP could be considered, with on-track results and data to better show their competition potential.
Thank you for your letter. In late 2020 the PAC requested that SCCA's Technical Services go through all of the Production spec lines and standardize how the specs are presented. They should be uniform to what is shown in the column headers, so that where applicable, they are presented in both units, with metric being shown first and English being shown second in parenthesis. This process has now been completed, and the updated formatting will be present in the 2021 December GCR. As this was a lengthy process of manually inputting these values by hand, it is requested that each competitor verify that the content of their spec line still appears to be accurate, and provide feedback if any discrepancies are found.
Thank you for your letter, but this is not recommended, as this classification belongs in HP. Significant variances in weight is something that exists in every non-spec production-based racing category. This change would also not change the group this vehicle would be racing in, or the vehicles it would be racing around. It is the responsibility of every competitor to be aware of their surroundings and their fellow racers, regardless of weight or class differences.
Thank you for your letter. How valve lift is to be measured on all Prep Level 2 cars is already defined in 9.1.5.E.2.f.7: “Where maximum valve lift is specified, valve lift is measured at the valve with zero lash or clearance. There are a few exceptions to this rule, where a spec line specifically allows for valve lift to be "measured as raced - w/ lash". These spec lines are from the original "Limited Prep" classifications that were made, many years ago, and that was the process/ruling at that time. As the "Prep Level 2" ruleset matured, and more waves of cars got classified to it, this measurement method was re-evaluated and changed to the current rule. Previous classifications have since been allowed to "grandfather" their original rules. Just as competition balance is monitored between Prep Level 1 and Prep Level 2 cars, the same is true for
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these original "pseudo-Limited Prep" classifications. Reverting this valve lift measurement process again would not make building these cars any easier, would not balance the performance potential of the field, and just tempt competitors to re-do their cam designs to chase an extra few thousandths of lift. Due to all of that, this request is not recommended.
Thank you for your letter. Specifically listing the allowed body styles in a spec line (i.e. coupe, sedan, convertible) isn't necessary. The competitor would just need to be able to prove that the vehicle/spec line they're choosing to complete with, did indeed ever come from the factory in the body configuration that they're using, if it was ever questioned.
Supports weight reduction for H and F Prod 1600 Corolla
Thank you for your letter. By fitting a vented rotor where a solid rotor existed originally, this would be considered the use of a "non-stock-size brake rotor", and be subject to the 2% "non-stock brakes" weight penalty.
Thank you for your letter. These recent additions to HP have been in FP for years, and despite several attempts at adjustments to improve their classifications, they have remained vastly uncompetitive. They simply cannot achieve a reasonable power-to-weight ratio for FP, given the weight of their chassis', the limitations of their stock engine and induction designs, and the Prep Level 2 rules. Through careful consideration of those limitations and their known performance capabilities within their FP and ITB classifications, and through an addition of weight and a reduction in Prep Level 2 compression and cam allowances as they moved from FP to HP, it is believed that these cars will now fit and race well in the existing realm of HP. As they get built, developed, and raced in HP, their performance will be closely monitored, and adjustments will be made if warranted.
Support for letter #30520, 2.0L ITB/ITC cars in HP
Thank you for your letter. The current classification appears to be reasonable. For further consideration, additional data needs to be provided and analyzed, including more on-track competition against other known classifications.
Thank you for your letter. This allowance is not recommended as requested. The Production Advisory Committee would like to remind all competitors that any IT car can already run in Production to its IT specifications, if a Production spec line already exists for it (rule 9.1.5.B.5). If a Production spec line does not exist, the creation of one just needs to be requested, and it will be done.
Thank you for your letter. The vehicle in question is proven to be competitive as classed, never came with carburation from the factory, and there's no performance or parts availability related case that can be made for why it should be allowed.
Thank you for your letter. With the new "non-stock brake calipers and rotors" allowance, that come with a pre-defined weight penalty, a new "Alt Brakes" package that permits a larger and vented rotor versus stock, is not going to be issued without weight penalty. If the letter writer wishes to run the package as he describes, it could be done with the "non-stock brake calipers and rotors" weight penalty.
Thank you for your letter. All previously existing "Alt Brake" allowances were permitted without a weight penalty. The new non- stock brake and rotor rules DO come with a weight penalty. The car in question in this letter can continue to run its permitted "Alt Brake" package with NO weight penalty, or install some other non-stock caliper and/or rotor package, with a weight penalty. The alternate carb weight adder on this vehicles spec line has nothing to do with its brakes, which again, are allowed without penalty.
#27417 (Jesse Prather) Alternate Brakes for Production
Thank you for your letter. No changes will be made to the new brake allowance rules at this time. As more races happen with cars that are utilizing these new rules, effects to competition balance will be reviewed.
Thank you for your letter. It is not believed that any additional changes need to be made to these rules. They already state that a vehicle must use its standard carburetor or an approved optional carburetor. A competitor must be able to defend that the carb he/she is using is either the stock carb, or an approved optional carb via its spec line or general Prod approved optional carb list. Additionally, further rules exist that define how a stock or optional carb can be adapted to a stock (or permitted) manifold. If for some reason a specific car cannot possibly adapt an approved carb to its approved manifold, within the current rules, addressing that would be a case-by-case basis.
Thank you for your letter, but the weights are correct as written. Although the engine of the 92-95 Civic DX is virtually identical to the 88-91 CRX/Civic 1.5L, the intake and fuel delivery systems are very different. The 88-91 CRX/Civic 1.5L uses a rather small dual-port down-draft throttle body, with two fuel injectors mounted into the side of it. The 92-95 Civic DX uses a true multi-port fuel injection system, with a intake plenum leading to four individual runners, one leading to each individual intake port, and each having its own fuel injector mounted at the head mating surface. In stock form, these differences were good for +10hp and +10tq. The letter writer is encouraged to campaign these vehicle on track, so that additional performance data can be collected.
Thank you for your letter. This change is not recommended. This classification is still relatively new, and its performance potential is still being developed and realized. As more get raced, more data will be collected in terms of lap times, sector times, and on-vehicle dynamics, which will allow the PAC to better monitor its capabilities and consider any future changes that may be needed.
Thank you for your letter. This part would already be considered unrestricted under the GCR definition of a "Hub" and Prod rule 9.1.5.E.b.6: "Hub – A component to which a road wheel is attached, which provides support for the wheel, and has the capability, via attached internal bearings to rotate on a fixed shaft." "9.1.5.E.b.6 - Wheel bearings and hubs are unrestricted." CLUB RACING BOARD MINUTES
Thank you for your letter. This change is not recommended, as the Fiesta never came with this head on it in the US-market. A weight break was also given to this car earlier in 2020, and the PAC would like to see it campaigned more in that new configuration before considering any additional changes.
Thank you for your letter. This change is not recommended. A "Targa-Type Top" is defined in the GCR as being fully removable above the driver's seats, while a "T-Type Top" is defined as having two separate removable sections, but that the roof is otherwise in a fixed position, and removing a fixed position roof is not within class philosophy.
Need balanced representation on Production Car Committee
Thank you for your letter, and interest in this subject matter. The makeup of the Production Advisory Committee is continually changing, but strives to keep a good balance of representation across all of the classes and marques, with both drivers and builders, from up and down the grid.
Thank you for your letter. This change is not recommended. One of the core ideas of Limited Prep is that the type and orientation of a vehicle's suspension design must remain stock. There are several classifications throughout the Prod category with this type of separate shock and spring layout, and how to prepare it to be fully adjustable within the current rules is well within reason.
Thank you for your letter. The CRB does not recommend any changes at this time. A fair amount of data has been collected on front running HP L1/L2 1275cc Spridget's over the past several years, and its performance and lap time potential on a majority of tracks appears to be within the expectations of HP. Its performance will continue to be monitored.
Opposes proposed brake rules change for production
Thank you for your letter. The first line in the proposed changes to the brake rules was specifically designed and worded to protect the continued use of all currently approved brake packages without any weight penalty, as listed in the "Brakes Std." and "Brakes Alt." columns of a vehicle's spec line. So if your vehicle already has an alternate package specified in the "Brakes Alt" column of its spec line, then its continued use would absolutely still be permitted without any weight penalty.
Opposition to Changes to the Brake Rules in Production
Thank you for your letter. The CRB does not recommend any further modifications to the currently proposed changes to the brake rules, but your concerns will be passed along.
Support Letter 27417 Except 6 Piston Front 4 Piston Rear Calipers
Thank you for your letter. The CRB does not recommend expanding the number of pistons on alternate calipers to 6. The responses to the distributed survey were overwhelmingly in favor of limiting caliper piston count to a max of 4. Market research has also shown that quality 4-piston alternate calipers are quite plentiful, while on average the pricing of similar 6-piston calipers increases.
Thank you for your letter. The introduction of ABS into the Production Category was discussed and surveyed at great length, while additional changes to the Brakes section of the rule-book were being considered. However, due to competitor response and feeling to this specific issue, as well as several other changes also being made to the brake rules at the moment, it is not recommended to add ABS into the Production Category at this time.
Request to Allow Modernization of Prod Brake Rules
In Production, GCR section 9.1.5.E.7., Brakes Level 1 and 2, make changes as follows: "a. Stock calipers must be retained. Cars fitted with integral hat brake rotors can convert to a two piece design hat and brake rotor. The alternate design hat must be made of ferrous or aluminum material. Alternate discs can be used, but must be made of ferrous material. Alternate drums can be used, but must be made of a ferrous or aluminum material. Alternate discs and drums must be the stock diameter, width and design. Brake rotors can not be cross drilled or slotted unless fitted as stock. Stock brake calipers and stock-size brake rotors may be used without penalty, as defined in the “Brakes Std.” and “Brakes Alt.” columns of a vehicle’s spec line. b. Any other non-stock brake calipers and/or non-stock-size brake rotors may be used with a penalty of 2% of the base weight.
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1. Non-stock brake calipers must have a max of 4-pistons and the caliper body must be made of ferrous or aluminum material. Calipers must be mounted in the same location and orientation as the stock positioning. Mounting brackets are unrestricted, but must be made of ferrous or aluminum material. Stock caliper mounting tabs may be modified or removed to facilitate caliper installation. In all other regards, non-stock brake calipers are unrestricted. 2. Non-stock-size brake rotors are unrestricted, provided they fit inside the max wheel limitations on a vehicle’s spec line. c. All brake rotors must be made of ferrous material, and can be cross-drilled and/or slotted. A two-piece hat and rotor design may be utilized, but the hat must be made of ferrous or aluminum material. d. Alternate drums can be used, but must be made of ferrous or aluminum material, and be the stock diameter, width, and design. b 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. Rear brake rotors must be solid and made of a ferrous material. Rear brake rotors cannot be cross drilled or slotted. 2. Rear brake rotor hats can be made of a ferrous or aluminum material. 3. 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 from converting to rear disc brakes under this rule. c f. Dual braking systems are required. Any dual brake master cylinder(s) and pedal assembly can be fitted. Pressure equalizing and proportioning valve devices are unrestricted. d g. Servo assists are unrestricted. e h. Drum brake wheel cylinders are unrestricted. f i. Brake pads and brake linings are unrestricted. g j. Brake lines are unrestricted. h k. The hand brake and its operating mechanism can be removed. i l. Brake Ducting Brake air ducts can be fitted. Front duct inlet(s) cannot extend to the side beyond the center-lines of the front wheels, or beyond the forward most part of the front bodywork/air-dam. Rear duct inlet(s) must face forward, cannot extend to the side beyond the center-lines of the rear wheels, or be located more than 24” forward of the rear axle center-line. 1. Brake air ducts can be fitted. 2. The front brake duct inlet(s) must not extend to the side beyond the centerlines of the front wheels, or forward of the forward most part of the front of the body or front air dam. 3. Rear brake duct inlet(s) must face forward, they must be located no more than 24” forward of the rear axle centerline and must not extend to the side beyond the centerlines of the rear wheels. m.4. Backing plates and dust shields are unrestricted."
Thank you for your feedback. The survey results are still being gathered, and its results will be the primary driving force for any changes that may occur.
Alternate Side draft Carburetor Intake Manifold (Prep 2)
Thank you for your letter. 9.1.5.E.2.b.7 is the governing rule for all intake manifold's for all Prep Level 2 vehicles, regardless of if the OEM piece or an allowed alternative is being used, unless otherwise specified on its spec line.
Thank you for your letter. It is believed that this would already be considered legal under the rule 9.1.5.E.1.m.1 and 9.1.5.E.1.m.1: "The use of alternate engine components which are normally expendable and considered replacement parts, such as fasteners, gaskets, seals, bearings, water pumps, etc., is permitted."
Thank you for your letter, but this request is not recommended at this time. No new knowledge has been presented to make performance potential expectations any different than originally believed. This classification has also not been campaigned enough to gather sufficient real world data, nor has it been campaigned at the highest levels and subject to thorough technical checks and investigation.
Request to measure Toyota push rod 2TC engine cam lift as raced
Thank you for your letter. This request is not recommended at this time. Factory valve clearances cannot be taken into account for every classification, nor is it believed that variances of this spec from car to car will have any effect on performance potential or class balance.
Thank you for your letter. The Production Advisory Committee (PAC) is committed to creating, managing, and balancing Production classifications and Production cars. The PAC does agree that every car actively being raced in B-Spec should have an available classification in Production. Effort has been made over the past several months to make the necessary additions to Production so that every make/model that was raced in BS at the 2019 Runoffs, now currently also has a Production classification that it could compete under. If there are any B Spec racers whose vehicle is still not included in Production, and they are interested in competing in Production, they are urged to send in a letter for Production classification. Please note that by running under a Production classification, the competitor
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is expected to compete to the 9.1.5 Production Category rules of the GCR. Please also note the current existence of Production Category rule 9.1.5.B.5, which allows Improved Touring cars (a non-Runoffs eligible category) to compete in the Production class in which the same make and model car is classified, but wholly under the preparation, modification, and classification of their Improved Touring spec line and the Improved Touring rules.
Thank you for your letter. There is not a significant advantage to allowing this, yet there's certainly some unintended consequence that could arise from it. Therefore, this is not recommended.
Thank you for your letter. This is not recommended at this time. There has not been a fully campaigned example of this car ran yet to provide additional data. Also note that the stock specs of its engine are very close to those allowed on its spec line.
Thank you for your letter. This classification is not recommended at this time, as 2.0L is considered too much displacement for HP. The Production Committee would like to see the 914-4 1.8L campaigned in HP, to better gauge the competitiveness of this vehicle.
Thank you for your letter. This allowance is not recommended at this time, because it is outside of the scope of Limited Prep. Also note that pistons are already unrestricted.
Changes for DT L1/L2 Engine Builds Due to Re-Write Omissions
Thank you for your letter. Not recommended as written. To be considered, valid reasoning and supporting evidence would need to be presented as to why the original OEM stock piece is unavailable and/or impossible to find, or is inadequate for racing purposes. Recommended alternate components would need to be presented, and why it/they would solve these problems.
Thank you for your letter. Several factors and seasons of results went into the decision to adjust the Yaris, not just the results of the 2018 Runoffs. The primary factor was a sizable accumulated collection of on-vehicle data from a variety of HP vehicles. A review of data showed the Yaris was strong in every performance category, which ultimately led to the adjustment being made. The PAC is committed to continually use all of the tools at its disposable to seek better parity across all of the Prod classes, which includes how the Yaris performs at its new weight spec.
Thank you for your letter. Additional performance balance adjustments are not recommended in HP at this time. Event results and data are continuously monitored at all styles of tracks, and competitors are encouraged to continue to develop and race their cars, in order to provide additional data points.
Thank you for your letter. The two Toyota Yaris generations have the same drivetrain, brakes, and coefficient of drag, their wheelbase, track, and height dimensions are all within one inch of each other, and both chassis' have been very successfully campaigned. The similarities are so great, that there isn't enough reason to treat their classifications differently.
Thank you for your letter. Per rule 9.1.5.E.9.a.8.C, closed top cars are already allowed to replace their rear glass with polycarbonate material: “Rear, door, vent, and quarter window glass can be replaced with a clear polycarbonate material having a minimum thickness of 3mm.” Allowance of any holes in the rear window is still not recommended.
Thank you for your letter. This change is not recommended at this time. Examples of the 1098cc full-prep engine have been ran in HP in recent years, and have been competitive when ran. However, additional data points are always welcomed, so the letter writer is encouraged to also run and provide more examples of this engine in competition.
Request to allow replacement of rear window glass in closed cars
Thank you for your letter. The Club Racing Board does not recommend this change. Openings in the rear window of closed roof cars could potentially weaken the window or allow exhaust fumes inside the vehicle.
Thank you for your letter. It is the task of the PAC to try and give a wide variety of vehicles the fair chance of being competitive, within the performance envelope of its classes, regardless of when that vehicle was originally built. This suggested class philosophy change would alienate a large number of HP racers, and effectively push them out of the category. The goal will remain to try and include as many vehicles into the performance realm of the Prod classes as reasonable. In HP specifically, newer cars are being classified, and meshing into its typical fields, adding to the sustainability and attractiveness of the class.
Supports Letter # 25426 Allow Drivers Seat Floor Pan