This track has been raced on 4 configurations (The Circuit, 2.57 mi; 2.92 mi; 1.83 mi; 3.02 mi). Laps on different configurations are not comparable, so only events on the 2.57 mile layout are shown; switch above to see the others.
One row per driver and car (a driver who changed cars has a row for each). Each cell is that driver's best in that car across the selected events, with the session it was set in. Best 5-lap stint is the mean of the driver's quickest five consecutive race laps, and consistency is how far their median race lap sat behind their best in that race (small is a driver who does it every lap); both come from the race with the best stint. The fastest in each column is purple, and a car whose best lap is more than 115% of the fastest in its class is greyed (marked ">115%" beside the driver) and left out of the colour scale. Click a column to sort, a row to highlight it.
Theoretical lap is the sum of the best sectors, whichever laps they came from, and never slower than the best lap (where a car's fastest laps were recorded without sector times, its best lap is used). The 115% mark is about the car's best lap only: a car whose best lap is within 115% of the fastest in its class is never marked. Greyed sectors with no theoretical lap mean the sector times on file do not add up to a believable lap. Letters refer to the events above; Q is qualifying, R a race.
Sectors
S1 SF → IM1 0.65 mi
S2 IM1 → IM2 0.75 mi
S3 IM2 → SF 1.17 mi
Spd In → Out 0.03 mi
Sectors are numbered in lap order from start/finish, whatever each event's timing called them; the loop names are SCCA timing's.
By car
Car
Class
Drivers
Lap
Qual
Race
Trap
S1
S2
S3
Swift Db6
FF
2
1:49.259Edward Erlandson
1:55.247Johnnie Crean
1:54.993Johnnie Crean
124.5Johnnie Crean
31.358Johnnie Crean
32.841Johnnie Crean
47.766Edward Erlandson
SWIFT DB-6 Honda
FF
1
1:49.259Edward Erlandson
47.766Edward Erlandson
Swift Db6
FF
1
1:54.993Johnnie Crean
1:55.247Johnnie Crean
1:54.993Johnnie Crean
124.5Johnnie Crean
31.358Johnnie Crean
32.841Johnnie Crean
50.291Johnnie Crean
Piper DL7-Honda
FF
1
1:51.118Eric Poulsen
1:52.044Eric Poulsen
1:51.118Eric Poulsen
114.7Eric Poulsen
30.276Eric Poulsen
31.650Eric Poulsen
48.818Eric Poulsen
Mazda Miata
EP/SMX
7
1:52.034Joe Carr
1:57.853Wesley Mollno
1:58.294Christian Hoagland
131.6Joe Carr
31.719Joe Carr
32.405Joe Carr
49.966Joe Carr
Mazda Miata
EP/SMX
2
1:52.034Joe Carr
1:57.885Christian Hoagland
1:58.294Christian Hoagland
131.6Joe Carr
31.719Joe Carr
32.405Joe Carr
49.966Joe Carr
Mazda Miata (2006)
SMX
2
1:57.853Wesley Mollno
1:57.853Wesley Mollno
1:59.001Wesley Mollno
112.1Wesley Mollno
32.080Wesley Mollno
34.047Wesley Mollno
51.618Wesley Mollno
Mazda Miata (2007)
SMX
2
1:58.557Jon Davies
1:58.557Jon Davies
1:59.608Jon Davies
112.1Patrick Drinkwine
32.013Jon Davies
34.268Patrick Drinkwine
51.616Jon Davies
Mazda Miata (2012)
SMX
1
1:59.056Emy Kissick
1:59.056Emy Kissick
2:00.430Emy Kissick
106.6Emy Kissick
32.502Emy Kissick
34.381Emy Kissick
52.026Emy Kissick
Mazda MX-5
EP/SMX
22
1:53.088Glen McCready
1:53.088Glen McCready
1:53.487Glen McCready
141.6Joey Andrews
30.761Glen McCready
32.765Glen McCready
49.458Glen McCready
Mazda MX-5
EP/SMX
3
1:53.088Glen McCready
1:53.088Glen McCready
1:53.487Glen McCready
125.6Glen McCready
30.761Glen McCready
32.765Glen McCready
49.458Glen McCready
Mazda MX-5 (2006)
SMX
8
1:56.431Ethan Lampe
1:56.431Ethan Lampe
1:57.417Ethan Lampe
141.6Joey Andrews
31.777Ethan Lampe
33.620Ethan Lampe
50.974Ethan Lampe
Mazda MX-5 (2013)
SMX
1
1:56.503Lincoln Larson
1:56.503Lincoln Larson
1:59.141Lincoln Larson
132.0Lincoln Larson
31.834Lincoln Larson
33.724Lincoln Larson
51.178Lincoln Larson
Mazda MX-5 (2012)
SMX
2
1:57.010Emy Kissick
1:57.010Emy Kissick
1:58.594Emy Kissick
133.6Emy Kissick
32.035Emy Kissick
33.863Gavin Wardle
51.449Emy Kissick
Mazda MX-5 (2008)
SMX
3
1:57.195Christian Hoagland
1:57.195Christian Hoagland
1:58.021Christian Hoagland
136.1Christian Hoagland
31.987Christian Hoagland
33.812Aidan Shimbashi
51.037Christian Hoagland
Mazda MX-5 (2010)
SMX
2
1:58.391Bryce Johnson
1:58.391Bryce Johnson
1:59.447Bryce Johnson
134.6Bryce Johnson
32.172Thomas Bellemin
34.074Thomas Bellemin
51.811Bryce Johnson
Mazda MX-5 (2007)
SMX
1
1:59.575Andy Chittum
1:59.575Andy Chittum
2:00.160Andy Chittum
132.0Andy Chittum
32.538Andy Chittum
34.495Andy Chittum
52.307Andy Chittum
Mazda MX5 (2010)
SMX
1
2:00.055Michael Travers
2:00.568Michael Travers
2:00.055Michael Travers
115.3Michael Travers
32.815Michael Travers
34.508Michael Travers
52.561Michael Travers
Mazda MX-5 (2015)
SMX
1
2:00.330Adrian Comstock
2:00.330Adrian Comstock
2:00.678Adrian Comstock
132.0Adrian Comstock
32.913Adrian Comstock
34.721Adrian Comstock
52.548Adrian Comstock
SWIFT DB-
FF
1
1:53.098Edward Erlandson
1:53.098Edward Erlandson
1:54.741Edward Erlandson
133.7Edward Erlandson
30.951Edward Erlandson
32.299Edward Erlandson
49.791Edward Erlandson
Mazda RX-7
EP
2
1:56.468Kurt Frietzsche
1:56.468Kurt Frietzsche
1:56.573Kurt Frietzsche
120.7Kurt Frietzsche
31.324Kurt Frietzsche
33.891Brandon Droese
50.204Kurt Frietzsche
BMW E30
EP
1
2:00.712Sean Lovett
2:00.712Sean Lovett
2:01.864Sean Lovett
127.6Sean Lovett
32.761Sean Lovett
34.806Sean Lovett
53.058Sean Lovett
Porsche Boxster
EP
1
2:01.940William Robinson
2:01.940William Robinson
2:02.887William Robinson
130.6William Robinson
32.969William Robinson
35.257William Robinson
53.408William Robinson
The best any driver of each car managed across the selected events, with who set it. Spellings and model years of the same car are grouped; click a row marked ▸ to see each version. Grouping is worked out from the names, so tell us if two cars are wrongly merged or split.
Rule changes between these events
Cal Club 2023 → Cal Club 2024 2023-02-24 to 2024-02-23
FF Add Fast Forward Part Numbers for Honda Fit Engine
#33752 from Formula/Sports Racing Committee · Rule change · TB 23-03 (2023-03 Fastrack)
neutralFF Honda Fit engine adds Fast Forward part number alternatives for intake, exhaust, oil system, and scavenge pump components.
In FC/FF, GCR section 9.1.1.B.14.a.6, change as follows: "For all Honda part numbers in these specifications, superc seding part numbers are considered equivalent. In FC/FF, GCR section 9.1.1.B.14.f.5, change as follows: "Cylinder head breather restrictor must be used as supplied by HPD or Fast Forward, unmodified.: HPD PN: 15262-F21S-A200; Fast Forward PN: FF200-503." In FC/FF, GCR section 9.1.1.B.14.k.2, change as follows: "The upper manifold, air box and throttle body assembly must be used as delivered from Honda, HPD, or Fast Forward as noted below."
Show 35 more lines
In FC/FF, GCR section 9.1.1.B.14.k.2, insert as follows: "a. Intake manifold: HPD PN: 17210-F21S-A210; Fast Forward PN: FF200-201. b. Throttle body: Honda Fit: PN: 16400ZZ5024; HPD PN: 16400ZZ5024; Fast Forward PN: FF200-104. c. Throttle lever: HPD PN: 17330-F21S-A210; Fast Forward PN: FF200-101." In FC/FF, GCR section 9.1.1.B.14.k.3, change as follows: "All gaskets and sensors utilized on the inlet manifold from head to throttle body must be Honda Fit OEM, or HPD supplied or Fast Forward as noted below. a. Gasket In. manifold: HPD PN: 17105-RB0-004, Honda Fit OEM. b. Gasket, EGR chamber cover: HPD PN: 17146-RB0-004, Honda Fit OEM. c. Gasket In. port: HPD PN: 17115-RB0-007, Honda Fit OEM. d. Gasket, restrictor: HPD PN: 17399-F21S-A200, (2 required) HPD; Fast Forward PN: FF200-109. Two required." In FC/FF, GCR section 9.1.1.B.14.k.5, change as follows: "The Honda Fit engine is required to have an HPD supplied air inlet restrictor supplied by HPD or Fast Forward: HPD PN: 17344- F21S-A201; Fast Forward PN: FF200-110, with internal diameter of 30.5mm and thickness of 3.175mm (0.125 inches) correctly installed within the intake system." In FC/FF, GCR section 9.1.1.B.14.m.1, change as follows: "The exhaust manifold must be as supplied by HPD or Fast Forward:, HPD part # PN: 18150-F21S-A200 or # PN: 1818 50-F21S-B200; Fast Forward PN: FF500-001 or PN: FF500-002." In FC/FF, GCR section 9.1.1.B.14.n.1, change as follows: "The oil pan, baffle plate, and scavenge pump filter fittings must be as supplied by HP or Fast Forward as noted below. No modifications are permitted. a. Oil pan: HPD PN: 11200-F21S-A210 or PN: 11200-F21S-C240; Fast Forward PN: FF100-201A or PN: FF100-201B. b. Oil pan baffle plate: HPD PN: 11221-F21S-A210; Fast Forward PN: FF100-202. c. Oil scavenge pump filter fittings (2 required): HPD PN: 15180-F21S-A210; Fast Forward PN: FF100-204." In FC/FF, GCR section 9.1.1.B.14.n.3, change as follows: "The scavenge pump and internal scavenge pump parts must be as supplied from HPD or Fast Forward as noted below." In FC/FF, GCR section 9.1.1.B.14.n.3, change as follows: "b. Rotor outside diameter: HPD 44.400mm (1.748 inches):; Fast Forward 40.640mm (1.600 inches). c. Scavenge pump rotor set: HPD PN: 15450-F21S-A20; Fast Forward PN: FF100-110. d. Oil pump: HPD PN: 15100-F21S-A200; Fast Forward PN: FF100-100A. e. Scavenge pump cartridge: 15111-F21S-A21; Fast Forward PN: FF100-127. f. Scavenge pump port A: HPD PN: 15137-F21S-A20; Fast Forward PN: FF100-101. g. Scavenge pump port B: HPD PN: 15139-F21S-A20; Fast Forward PN: FF100-102. h. Scavenge pump shaft: HPD PN: 15510-F21S-A20; Fast Forward PN: FF100-103. i. Scavenge pump front cover: HPD PN: 15070-F21S-A21; Fast Forward PN: FF100-104."
EP Investigate Parity of Z3
#33343 from Tim Schreyer · Rule change · TB 23-01 (2023-01 Fastrack)
slowerEP BMW Z3 2.5L intake restrictor reduced from 58mm to 56mm flat plate.
Effective 4/1/2023 In EP Spec Line BMW Z3 2.5L, change Notes as follows: "58 56mm Flat Plate Intake Restrictor is required with both stock or alternate throttle body."
fasterEP Porsche 914-6 2.0L intake valves increase to 2.0 mm, exhaust valves corrected to 38.0 mm.
In EP Spec Lines, Porsche 914 - 6 2.0L, change Valves IN & EX mm/(in.) as follows: "(I) 41.9 2.0/(1.65) (E) 38.1 0/(1.50)"
EP Correct Intake Valve Size on 1500cc Midget/Spitfire
#34419 from Production Committee · Rule change · TB 23-06 (2023-05 Fastrack)
neutralFP and HP Sprite, Midget, and Spitfire 1500 intake valve size corrected to 36.6/(1.44).
In FP Spec Lines, Austin-Healey Sprite Mk. I, II,III, IV MG Midget Mk I,II, III, IV & 1500, change Intake Valve Size as follows: "(I) 36.65.3/(1.44)" In FP Spec Lines, Triumph Spitfire Mk. IV & 1500, change Intake Valve Size as follows: "(I) 36.65.5/(1.440)" In HP Spec Lines, Triumph Spitfire 1500, change Intake Valve Size as follows: "(I) 36.65.5/(1.440)" In HP Spec Lines, Triumph Spitfire Mk. III & IV 1500, change Intake Valve Size as follows: "(I) 36.65.5/(1.440)"
EP Hub Note Clean Up In EP TR8 Spec Line
#34649 from Jeff young · Rule change · TB 23-09 (2023-09 Fastrack)
neutralEP Triumph TR8 78-81 removes alternate front hub allowance note; stock hubs now required.
In the EP Spec Lines, Triumph TR8 (78-81), remove the following wording from Notes: "Alternate front hubs are allowed provided they are of the same external dimensions as stock and weigh no less than the stock hubs."
EP Triumph GT6 Adjustments
#34662 from ANTHONY PARKER · Rule change · TB 23-09 (2023-09 Fastrack)
unclearEP Triumph GT6 carburetors change from SU or Stromberg to 1.5" Auto-type.
In EP Spec Lines, Triumph GT6, change Carburetor. No. & Type as follows: "(2) 1.5” SU or Stromberg Auto-type carburetor(s)"
EP Triumph GT6 Adjustments: Brakes
#34663 from ANTHONY PARKER · Rule change · TB 23-09 (2023-09 Fastrack)
neutralEP Triumph GT6 brakes may now use TR-6 standard or alternate calipers and discs.
In EP Spec Lines, Triumph GT6, add the following to Brakes Alt.: mm/(in.): "(F) Calipers & discs from TR-6 (std. or alt)"
EP Porsche 944/924S Rule Change Request
#35002 from Adam Achepohl · Rule change · TB 23-12 (2023-12 Fastrack)
neutralEP Porsche 944/924S combines 2.5L and 2.7L variants with new weights: 2250–2415 lbs depending on engine and year.
In EP Spec Lines, delete the Porsche 944/924S 2.5L (2V) (83-88) spec line entirely, and create a new spec line for Porsche 944/924S 2.5L(2V) 2.7L(2V) (83-89) as follows:
A specification table follows in the original; it is not shown here.
EP Triumph GT6 Adjustments
#35054 from ANTHONY PARKER · Rule change · TB 23-12 (2023-12 Fastrack)
fasterEP Triumph GT6 minimum weight reduced to 1800 lbs.
In EP Spec Lines, Triumph GT6, change weight as follows: "1830 1800"
EP Request to Review Z3 2.5 Spec Line
#35073 from Tim Schreyer · Rule change · TB 24-01 (2024-01 Fastrack)
slowerEP BMW Z3 2.5L weight increases to 2500 lbs, 2563 lbs with turbo, 2625 lbs with supercharger.
In EP spec line, BMW Z3 2.5L, change weight as follows: "2450 2500 *2511 2563 **2573 2625"
EP Miata Alternate Head
#35253 from Don Tucker · Rule change · TB 24-01 (2024-01 Fastrack)
fasterEP Mazda MX-5 1.8L 1990-97 minimum weight drops to 2150 lbs; 1994-97 variants to 2000, 2050, 2100 lbs respectively.
In EP Spec Lines, Mazda MX-5 /Miata 1.8L (90-97), change weight as follows: "2200 2150" Mazda MX-5 /Miata (94-97) "2035 2000 *2086 2050 **2137 2100"
Applies to Mazda Miata on this page: Joe Carr
Applies to Mazda MX-5 on this page: Glen McCready, Whitfield Gregg
EP Triumph GT6 Adjustments
#35255 from Anthony Parker · Rule change · TB 24-01 (2024-01 Fastrack)
In EP spec line, Triumph GT6, make the following change in the Notes section: "Two (2) 1.75” auto-type carburetors @ 1970 40 lbs. Three (3) Weber 40 DCOE on IR manifold with 28mm chokes @ 1990 lbs. Laycock overdrive, May use 5 speed gearbox w/o overdrive. Three (3) Weber 40mm DCOE w/28mm venturi on individual runner manifold @ 2020 lb."
EP Honda S2000 throttle body
#35272 from Aaron Johnson · Rule change · TB 24-01 (2024-01 Fastrack)
fasterEP Honda S2000 fuel injected throttle body inside diameter increases from 62mm to 64mm.
In EP spec line, Honda S2000, make the following changes to its spec line: Fuel Injected Equipped Throttle Body Inside Diameter: "62 64" Notes: "Comp. Ratio limited to 12.0:1. Valve lift limited to .500”. An adaptor plate can be used to mount the 62mm throttle body from '00-05 to the '06-09 intake manifold. The adaptor plate can be no more than 1.25" thick, and its bore must not exceed the "Fuel Injected Equipped Throttle Body Inside Diameter" maximum spec of 64mm."
neutralFF Honda Fit gains Fast Forward FF800-100 oversize piston ring pack option.
In FF, GCR section 9.1.1.B.14.e.3.a, add the following: "The standard ring pack, PN 13011-RB1-004 (Riken) or 13011-RB1-006 (Nippon), or the oversize ring pack, PN 13021-RB7-Z01 (Riken), or 13021-RB7-Z02 (Nippon), or FF800-100 (Fast Forward), may be used."
EP Correction within Triumph TR8 Spec Line
#35315 from Production Committee · Rule change · TB 24-01 (2024-01 Fastrack)
neutralEP Triumph TR8 dry sump allowance moved from carburetor line to notes section.
In EP spec line, Triumph TR8 (78-81), move the "Dry sump allowed" wording to the appropriate location as follows: Carburetor. No. & Type: “Zenith Stromberg carbs or fuel injection. Dry sump is allowed.” Notes: “Comp. Ratio limited to 12.0:1, Valve lift limited to .500”. Dry sump is allowed.”
EP Correction to EP 924S/944 Spec Line
#35317 from Production Committee · Rule change · TB 24-01 (2024-01 Fastrack)
neutralEP Porsche 944/924S 2.5L and 2.7L weight minimums corrected: 2479cc to 2306/2363 lbs, 2681cc to 2358/2415 lbs.
In EP spec line, Porsche 944/924S 2.5L (2V) / 2.7L (2V) (83-89), change Weight as follows:
A specification table follows in the original; it is not shown here.
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
neutralNissan 300ZX 84-89 classified to EP at 2550 lbs minimum, 2960cc 6-cyl SOHC, fuel injection, 12.0:1 compression limit, 0.500" valve lift limit.
In EP Spec Lines, classify Nissan 300ZX (84-89), as follows:
A specification table follows in the original; it is not shown here.
EP RX7 1993 and Up Request In EP Spec Lines, classify
#36031 from Edward Zabinski · Rule change · TB 24-06 (2024-06 Fastrack)
neutralMazda RX-7 92-97 newly classified EP Prep Level 2 at 2200–2310 lbs with 13B 6-port rotary engine.
Mazda RX-7 (92-97) as follows:
A specification table follows in the original; it is not shown here.
EP Clean-up Multiple EP RX-8 Spec Lines In EP
#36156 from Production Committee · Rule change · TB 24-06 (2024-06 Fastrack)
neutralEP Mazda RX-8 (04-11) alternate spec line removed; one primary line remains.
Spec Lines, make the following changes to the two Mazda RX-8 spec lines. Remove spec line entirely: Mazda RX-8 (04-11) Remove the wording "alternate": Mazda RX-8 (04-11)(alternate) Spec Mazda (SM/SMX) None.
neutralHP Volkswagen Golf and Jetta 85-92 track correction: front 1537mm (60.5in), rear 1529mm (60.2in).
In HP Spec Lines, change Track (F/R)mm/(in.) as follows: Volkswagen Golf (GTI, GT, GL) (85-92): "2 1537/1529 (60.5/60.2)" Volkswagen Jetta (GLI, GL) (85-92): "2 1537/1529 (60.5/60.2)"
SMX SMX Camera Rule Correction
#36496 from Paul Gauzens · Rule change · TB 24-09 (2024-09 Fastrack)
neutralSMX Spec MX-5 camera requirement wording changed; non-functioning recorder now grounds for penalty or disqualification.
In GCR, Section 9.1.7.1.D.21., change as follows: "Cars running in Spec MX-5 must have a functioning video recorder/camera during all qualifying and race sessions as described in 9.3.11. Upon request by an SCCA official, competitors must provide their video recording/data, which may be used by the SCCA for any purpose including but not limited to rule enforcement and marketing. Failure to comply with a video request from an official, or having a non-functioning video recorder/camera may will be grounds for penalty or disqualification."
neutralSMX Spec MX-5 must run latest AIM Data Logger Spec MX-5 ECU Protocol; wording clarification for technical compliance.
In GCR, Section 9.1.7.1.D.20., add the following: “e. All cars must run the latest AIM Data Logger Spec MX-5 ECU Protocol.” These specifications are part of the SCCA GCR and all automobiles shall conform to GCR Section 9. A. PURPOSE AND INTENT Spec MX-5 (SMX) is based on four pillars: affordability, reliability, tech-ability, and fun to drive, the (SMX) Spec MX-5 car provides the membership with the opportunity to compete in similarly prepared, low cost, 2006-2015 production-based MX- 5 car with limited modifications, intended to help deliver the most fair and competitive racing competition in SCCA Road
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Racing B. CLASSIFIED CARS AND WEIGHTS 2006-2015 production-based MX-5 Cars are to be weighed with the driver and required ballast. C. AUTHORIZED MODIFICATIONS Only the left-hand drive, North American-version of the 2006-2015 Mazda MX-5 convertible & power retractable hardtop (PRHT) are eligible. The original OE vehicle identification number (VIN) stamped on the firewall must correspond with the model year automobile as classified. VIN plates or stampings must remain in place, with the firewall VIN taking precedence. A Mazda Factory Shop Manual for the specific make, model, and year of automobile is required to be in the possession of each entrant. The manual may be in the form of printed material, microfiche, CDs, DVDs, and/ or Internet access to manufacturer sponsored web-based databases that is readily accessible at time of inspection. The manual is intended to aid scrutineers in identifying parts and the configuration of the automobile. The items outlined in this VTS document represent the only modifications and safety items permitted and/or required on Spec MX-5 vehicles other than safety items as required in SCCA’s current GCR Section 9. Parts and components may not perform an unauthorized function (i.e. Modifications must be stated as authorized or cannot be done). If the Mazda Factory Manual or these rules provide only a partial specification or no specification at all, the Mazda parts may not be modified beyond what is permitted in these rules. Compliance will be determined by comparison to new or like parts and/or the parts compliance measurement listing delivered by Mazda. Other approved parts with only a partial specification or no specification available in these rules may not be modified. Assembly, rebuild, and refurbishment procedures, and all associated dimensions must adhere to the published factory service procedures, except as otherwise stated in these rules. No components may be added or omitted from those specified by the published factory service procedures. All components must be comply with stated standard dimensions. It is permitted to use industry standard procedures to repair damaged components. The use of any painting, coating, plating, metal treatment process or impregnating substance (e.g., anti- friction, thermal barrier, oil shedding coatings, chrome, anodizing, REM, isotropic finishing, etc.) to any internal engine surface, internal axle components, internal transmission or differential surface, internal or external surfaces of the intake manifold, exhaust manifold or down tube, is prohibited. D. VEHICLE TECHNICAL SPECIFICATIONS (VTS) 1. Vehicle Weight a. The minimum vehicle weight with driver is 2,525.0 lb. 2. Ballast If ballast is required to meet the required minimum weight, it must be added as follows: a. A ballast base plate must be securely mounted using the factory OE passenger seat mounting bolt holes and bolts. Any number of additional segments of ballast may be attached to the base plate. b. Each segment of ballast must be fastened to the base plate with a minimum of two (2) one-half (1/2) inch bolts/studs and positive lock nuts of SAE Grade 5/ Metric 8.8 or better and must utilize large diameter, load distributing washers. In lieu of positive lock nuts it is permitted to positively thread the additional segments of weight into the base plate. c. Holes are not permitted to be drilled in the floor pan to mount ballast. 3. Chassis a. Towing eyes per SCCA’s current GCR Section 9.3 are required. There must be an arrow that strongly contrasts with the vehicle paint scheme pointing to each tow eyestrap. 9.1.7.1 SPEC MX-5 (SMX) b. All cars must use the front subframe PT# - NE51-34-800C c. All cars must use the rear subframe PT# - NE51-28-800B. d. OE strut tower brace is required; it is comprised of three (3) components; see Table 1 for part numbers. e. An engine to fender brace located on the passenger side of the engine bay may be used if mounted in such a way that it does not foul brake lines, fuel lines, or other systems that would interfere with the safe operation of the vehicle under race conditions – see Table 1 for allowed modifications. (Mazda Motorsports PT# 0000-07-5600) f. Disabling or removing of the door locking mechanism must be performed. g. To facilitate frequent lifting of the vehicle, a 3/4” boxed tube not to exceed 12” long may be added under the rocker panel inboard of the factory pinch weld flange on each side of the vehicle. h. Convertible tops/power retractable hard tops (PRHT) and attaching hardware must be completely removed. i. All chassis, structural, and electrical repairs, if performed, must be in conformity with factory procedures, specifications, and dimensions. Unless specifically authorized by the manufacturer for repair or permitted by these rules, no reinforcement (e.g., seam welding, material addition, etc.) is permitted. j. Removal of excess wiring is permitted provided it serves no other purpose and does not splice or interrupt the OE harnesses. Removal of the following systems is permitted: audio equip- ment; power seats; airbag/supplemental restraint systems components; heated seats; interior lighting; power windows; and power door locks. (No additional wiring may be added except as permitted in other sections - e.g., Section 16: Electrical Equipment.) Table 1: Strut Tower Brace Parts Description Mazda Part # Right Side of Strut Tower Brace NE57-56-48X Left Side of Strut Tower Brace NE57-56-49X Center Section of Strut Tower Brace NE57-56-48ZA k. A hole is permitted to be drilled in part #’s NE57-56-48X and NE57-56-49X to allow for access to the shock adjuster screw is permitted (it is recommended that the hole not be larger than 15mm); NE57-56-48X may be modified in order to allow room for the engine passenger side engine brace; no other modifications or other braces are permitted. l. MX-5 donor chassis with originally equipped with 16” OE wheels require installation of OE strut tower brace (part # NE57-56-35XA). m. To facilitate engine bay air flow for cooling purposes it is permitted to remove the section outlined below in red from OE PT# NE57-56- 35XA. Block-off plates must be installed at the fresh air vent for the HVAC module at the firewall under the cowl to isolate driver compart- ment from engine compartment. (FIREWALL BLOCKOFF PLATE 0000-07-5832) No additional modifications are permitted. 4. Body a. Interior and exterior door handles are required to remain operable. Alternate interior door handles or cord/strap are permitted. b. The driver’s and passenger’s side inner door structural panel may be removed to fit the cage. c. The stock side impact/anti-intrusion beam must not be modified or removed. d. Door locking mechanisms must be disabled or removed. e. A minimum of two (2) of the brake lights must be in working order per the current GCR Section 9.1. f. The two (2) OE unmodified, external mirrors for the correct the Mazda MX-5 (left and right) are required; they must be mounted in stock location and may not be modified. g. OE interior rearview mirror or an aftermarket rearview mirror must be used. h. 2006-2015 MX-5 bodywork may be updated or backdated, OE body parts only. (This includes Mazda OE accessory body parts such as trunk lid spoiler, side skirts, front air dam.) i. Mazda Motorsports’ fiberglass headlamp replacements may be used; (See table 2) no modifications or substitutions are permitted; exceptions: painting, covering, and wrapping. Table 2: Headlamp Replacement Covers Model Year Mazda Part # Description 2006-2008 0000-07-5818-LT Left Side 2006-2008 0000-07-5818-RT Right Side 2009-2015 0000-07-5819-LT Left Side 2009-2015 0000-07-5819-RT Right Side j. Lexan windshield may be used in place of the stock windshield. (Mazda Motorsports PT# - 0000-07-5101-5S) k. Windshield clips per current GCR Section 9.3 windshield clips are recommended. l. Hood and trunk pins or clips are permitted. Factory hood and trunk latches must remain intact and operational and may not be removed, disabled or altered. m. Front under hood weather strip must remain intact PT#- NE51-56-750 n. Rear under hood weather strip must remain intact PT#- NE51-56-760 o. Modification of release cables is permitted to facilitate external pull/opening straps/pulls/cords. p. A radiator screen of 0.125” minimum stainless-steel mesh may be added in front of the radiator. 1. The screen must be a single layer and must be installed to the bumper cover and or grill and be contained entirely within the bodywork of the vehicle. 2. Tape may be applied to the mesh screen. 3. The OE grill must remain intact. q. It is allowed to apply roll bar padding to the crash support bar (52-070) located behind the front bumper to prevent damage to the bumper. r. Front and rear fender lips may be rolled to prevent tire damage. s. Front OE fender liners must be intact and unmodified, except for what is allowed in section 13. J regarding brake ducts. Repairs due to on-track damage is allowed so long as it serves no other purpose. t. OE fog lights lens/glass must be removed. This will allow for the installation of brake duct kit (Mazda Motorsports’ part # 0000-03- 5301-NC.) The remaining opening from the fog light lens must either be blocked, or a connection must be made from the fog lamp opening/hole in the bumper fascia to a brake duct attached to the hub. u. Side marker lenses may be removed, and holes may be covered. v. OE hard top or the unmodified Mazda Motorsports hard top (part # 0000-07-5901-CC) are permitted. w. PRHT chassis cars must trim the finish panel with the 3rd brake light to fit one of the approved hard tops. 1. Hhardtops may be painted or wrapped. 2. OE hard top latches must be removed and replaced with positive fasteners. 3. The front of the hard top may attach to the upper windshield bar of the roll cage. 4. It is permitted to run one single piece of racer tape to cover the leading edge of the after- market hard top where it meets the factory windshield frame. 5. Openings beneath the hard top seal to the body are not permitted. The hard top must be securely mounted to the body of the vehicle and perform no other purpose. 6. Body repair must be performed to maintain stock body contours, lips, profiles, etc. body repair modification must not increase clearance. x. To improve driver’s exit through the window area, the driver and passenger vent window and vent window supporting frame may be removed as an assembly. 1. Vent windows may be modified to accept fresh air ducting. y. OE radio antennas may be removed. Antennas for two-way radios may be added. z. Insulation & undercoating may be removed. aa. All cars must run with both the front door windows fully open (i.e. fully down). 5. Cockpit / Trunk a. All interior trim components such as carpets, seats, cargo bins, seat belts, floor mat, firewall insu- lation/blanket, sound deadener patches, undercoating, radio systems, speakers, dome lights, grab handles, sun visors and their insulating and attaching materials, must be removed. Other than to provide for the installation of required safety equipment or other authorized modifications, no other driver/passenger compartment alterations or gutting are permitted. b. It is permitted to install a radio replacement panel. c. The outer edges of the dashboard may be cut the minimum amount required to install the roll cage. d. Air bag systems must be disarmed and must be removed. e. It is permitted to remove all components of the cruise control system. f. The top portion of the door panels containing the door latch release handle must remain intact. g. The lower portion of the door panels must be removed for installation of the roll cage. Gutting of the door may not go outside of the factory seal. h. The door window glass and window operating mechanisms must be removed. i. The OE dashboard and its attaching hardware and brackets must be retained. j. For installation of required safety equipment, however, it is permitted to modify the OE dash bar, so long as it is outboard of the first dash support brackets (illustration below). Modification of the first dash support brackets, nor inboard from them, is not permitted. The OE dash bar must be securely mounted. k. The HVAC control module located under the dash may be removed together with the following: blower motor, evaporator core, heater core and associated ducting. Once removed it is permitted to block the blower inlet passage on the firewall. l. All openings between the driver/passenger compartment and the trunk / gas tank area that include the filler tube & fuel tank vent must be filled completely with a metal bulkhead that is securely mounted (E.G. nuts/bolts, nut-serts, rivets). This shall close the entire trunk from the driver/ passenger compartment and comply with current GCR Section 9.3. m. Mazda Motorsports’ finish panel trim kit (part # 0000-07-5822) may be used to create the required bulkhead above n. It is permitted to remove the driver’s side factory seat mounts, but not the floor pan. o. It is permitted to remove the horn and all associated horn related components. p. OE driver’s seat must be replaced with a one-piece bucket-type race seat per current GCR Section 9.3. q. The passenger seat must be removed. r. Any steering wheel except wood rimmed types may be used. s. Any shift knob may be used. t. The air conditioning equipment located in the engine compartment (AC compressor assembly, associated lines/dryer and the condenser) must be removed. u. Alternate gauges and instruments may be added. The original instrument cluster must remain connected and functional However, it may be relocated to allow the mounting of an aftermarket dash such as an AiM. The wiring to relocate the dash may not be cut or extended, it may only be re-routed. The remainder of the dashboard or panel must remain intact. v. Modifications may be made to the foot pedals to improve the comfort and accessibility to the driver; relocation of mounting points is not permitted. 1. Dead pedal/footrest and heel stop may be added. w. Instrument clusters must be unmodified OE parts . x. Two-way radios may be used. y. Alternate means of windshield defrosting is permitted 6. Engine Modifications 6.1. General a. No modifications to the engine are permitted, except where specifically authorized within these rules. This includes but is not limited to: all fuel injection and engine management components, as well as electrical, cooling, and lubrication systems. b. All systems, unless otherwise stated, are subject to test procedures and must conform to OE specifications as stated in the Mazda Factory Service Manual. c. Permitted engine maintenance includes the replacement, but not modification, of external engine and engine systems parts. 1. No balancing, blue printing, lightening, polishing or other modification of moving parts of the engine is permitted. 2. All parts in the engine must be OE parts unless specified in this rule set. 3. For all Mazda part numbers in these specifications, superseding part numbers are consid- ered equivalent. d. Compression ratio for 2.0L engines must be 11.00:1; calculated using the official Spec MX-5 calculator. 6.2. Engine Block a. The engine block may be decked or milled to achieve the class specified compression ratio. Honing of cylinders is permitted to accommodate piston clearance so long as a maximum standard diameter is not exceeded shown in Table 3. b. The cylinders may be bored to accommodate piston clearance requirements so long as maximum permitted overbore diameter is not exceeded shown in Table 3 below. Table 3: Piston Sizes Piston Part # Bore Diameter Max Standard 0000-01-5310 87.6046mm (3.449”) Allowed Overbore (.020) 0000-01-5310-OS 88.1126mm (3.469”) c. It is not permitted to overbore a single cylinder; all cylinders must be bored equally. d. Sleeving of cylinders is not permitted. 6.3. Crankshaft a. OE Mazda MZR 2.0L (2009-2015) manual transmission crankshaft (part # LF9G-11-301) must be used with no modifications except for machining or polishing polishing and/or machining of the bearing surfaces to allow the use of main and rod bearings as permitted in Table 4 below. Table 4: Crankshaft Measurements easurement iameter Diameter b. OE crankshaft (Mazda part # LF9G-11-301) must weigh a minimum of 31.75lb. c. Maximum permitted stroke is as follows: 3.27” / 83.1mm d. Shot peening is prohibited. e. Bearings 1. Main and rod bearings must not be modified; coatings are not permitted. 2. OE bearings are permitted. 3. The only bearing sizes permitted other than OE are listed in see Table 5. Sizes Bearing Type Minimum Bearing Width Minimum Bearing Thickness Minimum Bearing Weight Part # Main Bearings (Standard H) .630” 0.097” N/A 0000-01-5215-MB Main Bearing (Standard HX) .630” 0.097” N/A 0000-01-5216-MB Rod Bearings (Standard H) .630” 0.057” 28g 0000-01-5213-RB Rod Bearing (Standard HX) .630” 0.057” 28g 0000-01-5214-RB f. The crank trigger must not be modified; it must be installed per the Mazda Factory Service Manual. g. OE crank pulley/balancer (Mazda part # LF94-11-400) must not be modified and must be installed per the Mazda Factory Service Manual. h. Knife edging of the crankshaft is not permitted. i. Modifications to the crankshaft counterweights are not permitted. j. Coatings, REM or metal treatments of any kind are not permitted. k. Alternate shifter bushing located at the bottom of the shift lever is allowed. 6.4. Connecting Rods a. OE Mazda MX-5 (2009-2015) manual transmission unmodified connecting rods (part # LF9G- 11-210) must be used. Connecting rod weight with cap and bolts must not be less than 530 grams. 6.5. Pistons a. Mazda Motorsports’ competition pistons (standard bore part # 0000-01-5310; oversized part # 0000-01-5310 OS) are required; no modification is permitted. b. The minimum weight of the piston, less wrist pin and hardware, must not be lighter than 290 grams. c. Mazda Motorsports’ competition wrist pin (part # 0000-01-5310-PN) must be used. d. The minimum weight of the wrist pin must not be lighter than 80 grams. e. Modification of the piston ring end gap width is permitted. 6.6. Cylinder Head a. Mazda Motorsports’ competition cylinder head (part # 0000-01-5300) must be used; no modi- fications to the cylinder head are permitted outside of the gasket face surface outlined below in Table 6. b. Intake runner CC volume is 182cc +/- 1cc. c. Exhaust runner CC volume is 114cc +/- 1cc. d. Combustion chamber volume may not be below 41cc. e. The gasket face of the cylinder head may be resurfaced provided the maximum allowed compression ratio is not exceeded. I. Surfacing of the head gasket surfaced must be in a flat plane. II. Cylinder head gasket surface distortion may not exceed .010mm or 0.004”. f. The minimum height of the cylinder head as measured must be at least (TBA) g. The following head gaskets in Table 6 below are permitted; no other gaskets may be used. Table 6: Head Gasket Measurements Description Thickness Mazda Part # OE Gasket 0.017” approximate crush depth L3G2-10-271A Competition Gasket 0.55mm (0.021”) 0000-01-5319-21 Competition Gasket 0.75mm (0.030”) 0000-01-5319-30 Competition Gasket 1.0mm (0.040”) 0000-01-5319-40 Competition Gasket 1.3mm (0.051”) 0000-01-5319-51 6.7. Camshaft and Camshaft Timing a. Camshafts must not be modified; see Table 7 for OE camshaft part numbers. Table 7: Camshaft part numbers Description Mazda Part # Intake Cam L3E3-12-420 Exhaust Cam L309-12-441B b. Camshaft and crankshaft sprockets must not be modified; see Table 8 for part numbers. shaft Sprocket Part #s t # 4X0C 425 c. Cam timing must not be altered; chain must be installed as stated in the Mazda Factory Service Manual. d. OE timing chain (Mazda part # LF7A-12-201) is required; no modification is permitted. e. OE timing chain components must be used; see Table 9 for Mazda part numbers. Table 9: Timing Chain Guide Part #s Description Mazda Part # Fixed Guide LF01-12-614 Tensioner Guide LF01-12-671 6.8. Valves a. OE valves must not be modified (including reshaping); see Table 10 for Mazda part numbers. le 10: Valve Part #s b. Valve location or angle must not be moved. c. Valve guides may not be replaced. d. Valve job measurements must be as follows: 1. Intake 35 top 45 seat 65 bottom 77 bottom seating angle width is 1.0mm 2. Exhaust 40 top 45 seating to radius seating angle width 1.2 mm. 3. Valve stem installed height must be per the Mazda Factory Service Manual. 4. Valve stem seals must be OE. 6.9. Valve Springs a. Mazda Motorsports’ competition valve springs (part # 0000-01-5319-SP) are required. 6.10. Intake Manifold a. OE intake manifold (Mazda part # LF9G-13-130B) is required; no modification is permitted (e.g., no material may be added or removed; no painting or coating on the exterior or interior permitted). b. All air entering the engine must pass through the throttle body and metered by the mass airflow sensor. c. Removal of these factory EGR components is permitted: Valve, crossover pipe, coolant lines (EGR DELETE KIT 0000-06-5447) d. If factory EGR components are removed, the following ports must be blocked: 1. Intake manifold cross over pipe port. 2. Cylinder head cross over pipe port. 3. EGR valve port on back of cylinder head. 6.11. Intake System a. Cars must replace OE air box with the Mazda competition cold air intake kit (part # 0000-06- 5150-KT); no modification (e.g., ducting or baffling of air, venturi cones) to the cold air intake kit is permitted. b. No alteration to the intake tube length, diameter, or shape is permitted. c. The air filter supplied in the Mazda Motorsports competition cold air intake kit may be refreshed with the Mazda Motorsports’ competition air filter (part # 0000-06-5204). 6.12. Fuel System a. Fuel must comply with SCCA GCR section 9.3.25 b. OE fuel pump (Mazda part # LFG1-13-350) is required; no modification is permitted. c. It is permitted to remove the unleaded fuel restrictor from the filler neck. (GCR 9.3.26) d. Mazda Motorsports’ competition fuel rail that includes fuel pressure gauge, and fuel sampling test port and hose kit (part # 0000-06-5207) is optional. 1. Fuel pressure sensor integrated into the required AIM data acquisition system is required. It must be operational and able to be viewed when pulling a competitor on track data. 2. The addition of a switch or jumper located in the under-hood fuse box is allowed to acti- vate the fuel pump. This modification may serve no other purpose. 3. One operational fuel sample test port is required. Fuel sample test ports shall be made from dry break fuel rated quick disconnects. No other style of fuel sample test port is allowed (e.g., Schrader valves). 4. No other modifications permitted. e. OE fuel pressure regulator (Mazda part # LFB6-13-280) is required. 1. Vehicle must run between 54 and 63 PSI of fuel pressure. f. OE injectors (Mazda part # L3G5-13-250) are required; no modification is permitted. 1. Flow rates for the injectors must fall within the factory tolerance of 204-216ml (204-216 cc, 12.5-13.1 cu in/minute). 6.13. Lubrication System a. OE engine oil filter is required; no substitutions permitted. b. OE oil pump PT# L310-14-100J is required and no modifications are permitted. c. Mazda Motorsports’ competition oil cooler adaptor kit with lines (part # 0000-01-5100KT) is required; no modification is permitted. d. Oil pressure sensor integrated into the required AIM data acquisition system is required. It must be operational and able to be viewed when pulling a competitor on track data. e. Oil and lubricants are unrestricted. 6.14. Engine Control Unit (ECU) a. Reference penalties for non-compliance of the Spec ECU flash in Section 21 below. Modifica- tion or attempted modification of the Spec ECU flash will result in a 12-month suspension from competition and $1,000.00 fine. b. Mazda Motorsports’ competition ECU (part # 0000-01-5379) is required; serial number must be visible; external or internal modification is not permitted. c. ECU calibrations and inputs must not be modified. d. OE engine electrical harness (part # NH18-67-020A) is required; no modification is permitted. e. OBDII diagnostics port must be operational in all cars. 1. The check engine light must be operational and perform the function test at start up. 2. The OBDII port must be available at all times (including during the race) for tech officials to install test equipment as necessary. 3. If a competitor uses the OBDII port to power any type of data acquisition system, he/she would be responsible for providing the splitter cable to plug in both units or unplug the data acquisition system. f. Instrument panel clusters must be operational and unmodified OE parts. g. Temporary data acquisition devices may be installed by the sanctioning body for technical compliance. h. Removal of Mazda ECU insulator PT# LFG1-13-3C1 is permitted (diagram below) 6.15. Miscellaneous a. The factory air conditioning system and all associated lines, compressor, condenser and evap- orator must be removed. 1. Once the AC compressor is removed, the OE AC pulley delete kit (Mazda part # LF17-15- 940E) is required. b. Serpentine belt Gates PT# 6PK-2170 or same size equivalent is required. 7. Exhaust a. OE exhaust manifold and OE heat shield must be replaced with Mazda Motorsports’ competi- tion part # 0000-06-5407-NC; no modification is permitted (e.g., internal or external wraps, coatings, paints, metal treatments, thermal barriers etc.). b. OE exhaust system must be replaced with Mazda Motorsports’ competition part # 0000-06- 5427-NC; no modification is permitted (e.g., internal or external wraps, coatings, paints, metal surface treatment, thermal barriers etc.). c. The forward oxygen (O2) sensor (OE Lambda Sensor) must remain in the factory location and in full working order. Mazda Motorsports’ competition O2 sensor installation kit wiring extender (part # 0000-10-5320) is permitted. d. The secondary post catalytic oxygen (O2) sensor must be removed. e. Heat shielding 1. OE heat shield protecting ABS unit from header may not be removed or modified. 2. OE muffler heat shield may not be removed or modified. 3. It is permitted to wrap the exhaust pipe from the mid connection flange to the muffler. (see red arrows in picture below) 4. Use of heat shielding material on transmission tunnel to replace OE heat shielding is permitted. OE heat shielding must be removed from transmission tunnel. (see diagram below) 8. Cooling System (cooling system checklist) a. Mazda Motorsports’ competition radiator and oil cooler assembly (part # 0000-01-5504-CR) is required (e.g., OE is not permitted). b. The radiator using the OE mounting brackets must be installed in its original location. c. The oil cooler may not be moved or altered from the pre-assembled mounting location. d. Radiator ducting may be placed on each side of the radiator tanks and the undertray to force air through the radiator fins. The gap between the top and sides of the radiator may be sealed but shall not perform any other function. e. The unmodified OE cooling fan must be maintained in full working order and mounted in the stock location. Axillary control of the radiator cooling fan may be added to activate the fan independent of the ECU, OE control of the fan must remain intact. f. Thermostats may be modified, removed or replaced. g. The OE water pump (Mazda part # 1F70-15-100) is required; no modification is permitted. h. The OE water pump pulley (Mazda part # L327-15-131) is required; no modification is permitted. i. Engine cooling system hoses and clamps may be substituted. j. The heater core may be removed along with HVAC evaporator core including all associated hard pipes and hoses. This is to include OE water to oil cooler lines as well as throttle body coolant lines. (Rear coolant pipe 0000-01-5514, bottom coolant pipe 0000- 01-5515) k. The OE engine coolant expansion tank may be replaced with any aftermarket part but and must not serve another purpose. 9. Clutch, Pressure Plate and Flywheel a. Vehicle may use any combination of the options listed in Table 11 below. Table 11: Clutch Component Part Numbers Description Mazda Part # Mazda Factory Clutch Disc LF05-16-460A ACT Sprung Clutch Disc 0000-02-5420-AC ACT Pressure Plate 0000-02-5405-AC ACT Clutch and PP Kit 0000-02-5004-G6 Mazda Factory Pressure Plate LF04-16-410A b. The unmodified pressure plate must be bolted directly to the stock, unmodified flywheel. c. OE flywheel (Mazda part # LF9G-11-500) is required. Factory Service Manual resurfacing specification is permitted; no other modification is permitted. d. Alternate clutch lines are permitted but must not serve another purpose. e. Clutch components must adhere to the minimum weights listed in Table 12 below: Table 12: Clutch Component Part Numbers Description Minimum Weight (lb.) Clutch disc 3.5 Pressure Plate 9.4 Flywheel 15.80 10. Transmission a. OE 2006-2015 6-speed gearbox and 4.10 final drive ratio are required. b. No modification of the internal parts and ratios are permitted except the installation of the unmodified parts contained in the Mazda Motorsports MX-5 transmission upgrade kit (part # 0000-02-5700). c. Mazda Motorsports Competition gear set 0000-02-6000 is allowed. Gear ratios are as follows: 1st - 3.82; 2nd - 2.26; 3rd - 1.64; 4th - 1.18; 5th - 1.00; 6th - 0.83/0.79. There are two (2) production 6th gears; either one is permitted. d. Alternate shift knobs are permitted. e. Nomex or aftermarket fireproof shift boots are permitted. Removal of the factory rubber shift boot is not permitted. f. No treating, coating, polishing or modification of any transmission or components are permitted. g. Fluids and/or lubricants may be substituted with any lubricant. h. Updating or backdating of transmissions from 2006–2015 is permitted; unmodified OE shifters must be retained. The use of short throw shifters is prohibited. i. An single inspection hole (not to exceed 1.5” in diameter) in the bottom of the bell housing is permitted for the sole purpose of technical inspection of the flywheel. It is permitted to plug or tape over theat hole. j. Transmission cooler(s) are permitted. 11. Differential a. Only the Following differentials are allowed. 1. Mazda Motorsports, unmodified, Torsen limited slip differential – 0000-02-5564 2. OE, unmodified, limited slip differential - Mazda part # MS03-27-200B 3. OE, unmodified, open differential are permitted. b. RX-8 differential mounting bracket (Mazda part # F151-39-730B) is permitted. c. Mazda Comp diff bushings 0000-04-5510 is permitted (MX-5 diff mount) d. Polishing, metal treatment or coating of differential or axle components are not permitted. e. Removal of metal/rubber isolator on the pinion flange is permitted. f. Differential cooler(s) are permitted. 12. Suspension and Steering: Suspension Modifications are limited to the addition of the Mazda Motorsports Spec MX-5 kit; details are as follows (including all modifications permitted): a. OE control arms are required; no modification is permitted. b. Mazda Motorsports’ TSB MX-5-002 must be followed re: the rear shock thread protector found in the “Spec MX-5: Four Pillars” page on MazdaMotorsports.com. The thread protector must measure 1.250”. (The TSB will not be applicable to the supply from Mazda Motorsports received after 7.15.2020 as they will have the updated thread protector.) c. Anti-roll bar links may be replaced with Mazda part # 0000-04-5597-KT 1. Cockpit adjustability is not permitted. d. Mazda Motorsports’ competition sway bars are required, mounting guidelines: 1. Metal shims up to 1/8” total thickness are permitted between each anti-roll bar mount shackle and the stock mounting point on the chassis. 2. One end of the sway bar(s) may be disconnected as a suspension tuning aid. 3. The bar must remain in place and be solidly attached to the suspension on one end. 4. Sway bar end links must be installed on the unmodified stock attachment points. e. Camber, caster, and toe are unrestricted within the limits of the unmodified factory adjust- ments in conjunction with Mazda Motorsports front offset bushing (part # 000-04-5407-NC). f. Minimum ride height is unrestricted. g. Nuts & bolts may be replaced by similar items performing the same fastening function(s). h. Relocation or reinforcement of any suspension parts or mounting points is not permitted, with the following exceptions: 1. Addition of spacers or washers on a horizontal plane is permitted at the rear lower shock mount to the spindle per the shock installation instructions. 2. Updating to RX-8 rear toe link and rear trailing arm is permitted. See Table 13 below. Table 13: Permitted RX-8 Trailing Arm and Toe Link Part #s Description Mazda Part # RX-8 Trailing Arm F189-28-200A RX-8 Toe Link F189-28-45XA i. OE power steering pump with pulley (Mazda part # NE51-32-650D) is required; Mazda Motor- sports Power steering flow restrictor PT#- 0000-04-5532 is permitted; no other modification is permitted. j. OE power steering rack (Mazda part #: NE51-32-110C) is required; no modification or reloca- tion is permitted. k. Factory power steering reservoir may be replaced. l. Wheel center caps must be removed. m. All chassis, structural and electrical repairs must follow factory procedures, specifications, and dimensions as described in the applicable service manual. Reinforcement (e.g., seam welding, material addition, etc.) is not permitted. n. Steering lock mechanisms must be removed. o. The distance from the outside of the wheel rim to outside of the opposing wheel rim for both the front and rear of the vehicle must not exceed 69.5”. I. The distance Measurement is obtained by measuring the distance between the wheel lips by going through the wheel spokes at the bottom of the wheel at its widest point via tape measure. (Measure the outside wheel lip of one wheel to outside wheel lip of the other wheel on same axle.) p. Mazda Motorsports’ competition rear toe link (part # 0000-04-5426) is permitted; no modification is permitted. q. Mazda Motorsport’s Spec MX-5 Suspension Kit includes the items set forth in Items in Table 14. seen below are components within this kit. No substitutions or modifications of parts are permitted. The unmodified kits must be used in their entirety, except as specified. Table 14: Spec MX-5 Suspension Kit (All parts are required; no modification is permitted.) Description Location Mazda Part # Shocks Front 0000-04-5291-SA Rear 0000-04-5292-SA Springs Front 0000-04-9700-08 Rear 0000-04-9400-07 Helper Springs Front/Rear 0000-04-9926 Front Penske Mount Kit Front 0000-04-5359 Rear Penske Mount Kit Rear 0000-04-5358 Sway Bar Kit Front and Rear 0000-04-5306-EB Offset Bushings Front 0000-04-5407-NC 13. Hubs a. OE RX-8 front hub (Mazda part # F189-33-04X) may be substituted in place of the OE Miata 2006-2015 front hub. b. Mazda Motorsports’ competition RX-8 rear hub upgrade kit (part # 0000-04-5811-KT) may be substituted in place of the OE MX- 5 rear hubs; this unmodified kit must be used in its entirety. c. OE RX-8 rear uprights, bearings, hubs, and hybrid axel may be used in place of OE MX-5 parts. 14. Brakes a. OE brake rotors must be used and adhere to the specifications below in Table 15. Table 15: Brake Rotor Dimensions Location Diameter Notes Front 290mm (11.4”) Vented Rear 280mm (11.0”) Solid Front backing plates/dirt shields may be removed. (see see red arrow in diagram below) b. Rear backing plates/dirt shields may be removed. (see red arrow in diagram below) c. Brake lines may be replaced with competition braided steel lines; option: Mazda Motorsports’ part # 0000-03-5212. d. The Factory ABS system must remain intact, unmodified, and in full working order. e. Brake slider pin may be used in either/both front location B25D-33-694. (This prevents a stuck sliding caliper due to the rubber grommet) f. Parking brake mechanisms and actuating components may be removed. g. Brake fluid is unrestricted. h. Mazda Motorsports’ competition brake duct kit (part # 0000-03-5301) is permitted. i. The forward vertical inner fender panels may be modified to fit the brake kit hose to the fog light openings but may not be modified to serve any additional purpose. j. Mazda Motorsports’ competition brake pads are required; see eligible brake pad compounds in Table 16. No other brake pads are permitted. Table 16: Brake Pad part numbers Pad Style Mazda Part # Notes Front Pad 0000-03-5104-SP RST-3 compound Rear Pad 0000-03-5116-29 RSL-29 compound 15. Wheels The following unmodified wheel options below in Table 17 are permitted for use. Table 17: WHEELS Description Color Mazda Part # 17x7” OE Wheel Gun Metallic 99656-47070 17x7” OE Wheel Silver 99656-77070 Mazda Motorsports’ Competition MX-5 Wheel Gun Metallic 0000-04-5706-GM Mazda Motorsports’ Competition MX-5 Wheel Silver 0000-04-5706-SL a. Wheels may be painted. b. Aftermarket (any) wheel studs and lug nuts are permitted., provided that a minimum of two he threads must protrude beyond the lug nut with the wheel installed with a minimum of two (2) full threads showing; Wheel studs may not be gun drilled. c. Wheel spacers are not permitted. 16. Tires a. Dry tires: Toyo RR P235/40/ZR17 b. Wet tires: Toyo RA1 P235/40/ZR17. 17. Electrical Equipment a. OE ignition coils (Mazda part # L3G2-18-100B) are required; no modification is permitted. b. Mazda’s competition spark plugs (part # 0000-10-R7IX-11) are required; no modification is permitted. c. The crankshaft position sensor and crankshaft pulley relationship must be as specified in the 2006- 2015 MX-5 Factory Service Manual. d. One of the two OE alternators (Mazda part # LF9H-18-300R-OA, L3P9-18-300D) is required; no modification is permitted. e. The alternator must not be externally regulated or disabled in any way other than by the OE production ECU/wiring circuit and master kill switch. f. The electronic control module (ECM) control circuit for alternator charging must be OE - unmodified and operational. g. One of the two OE alternator drive pulley part # AJ51-18-W10 (60mm), Part# L813-18- W11(55mm) is required; no modification is permitted. h. All sensors related to engine operating parameters must be used and must be stock, unmodi- fied Mazda parts for the correct year of the vehicle on which they are installed. i. Any and all sensors and their respective locations, mounts, and wiring harness leads may not be altered except as elsewhere in this rule set. e Spec-MX-5 rules. j. Any sensors required for non-OE gauges must be in addition to the Mazda sensors. k. All alternate gauge and sensors must have independent wiring. Splicing, tapping, or altering of the factory engine wiring harnesses is prohibited with the exception of adding an aftermarket tachom- eter/shift light as follows: 1. It is permitted to splice into the yellow wire with the black stripe (pin 2BA - Ignition Coil 1 control circuit) in the engine harness to obtain the tachometer signal for an aftermarket tachometer or shift light. 2. Splicing must be done within 5” of the ECU. l. Data acquisition’s sensor(s) may be added, provided they do not require splicing or alteration to the factory engine wiring harness. m. Batteries 1. Batteries may be replaced with those of an alternate manufacturer, provided they are of similar amp-hour capacity, and size, including lead acid or AGM.; lLithium batteries are not permitted. 2. Batteries must weigh no less than 18.0lb and no more than 35.0lb 3. Additional battery hold-down devices are recommended. 4. Battery MUST be moved from the original location to the passenger side in the upper trunk area in front of the tail lamp. This will require the use of a bulkhead that separates the driver / passenger compartment completely from the trunk and the battery location. See section 5.I for reference. 18. Roll Cage a. Roll cage must adhere to SCCA’s current GCR Section 9.4 for Touring 4 cars; with the following exceptions: 1. One tube not to exceed 1.75” in diameter may be added which extends from the door bars to the rocker panel on each side. The landing plate for this tube can be no longer than 5” in length. The landing plates must be centered between the front and rear landing plates for the lower NASCAR or X brace bar. 2. Main hoop mounting plates may be on multiple planes; however, they must not be greater than 19” on any side. b. Playboy MX-5 Cup car cages manufactured by Racing Cages, Inc. with the official serial number plate on the main hoop are allowed to retain the lower door bar and two 3” attachment points to the rocker panel on both the driver’s side and passenger side. No additional seam welding or lengthening of the original attachment points is allowed. 19. Safety a. An electrical master (“kill”) switch is required. See current GCR Section 9.3 Master Switch. b. Vehicle must be equipped with a driver’s restraint system meeting the specifications of current GCR Section 9.3 Drivers Restraint System. c. Installation of a fire extinguisher or fire system is required. See current GCR 9.3 Fire System. d. Vehicle must have a driver’s side window safety net complying with current GCR Section 9.3 Window Safety Nets. Nets must be mounted to provide protection in the event the driver’s door opens. 20. Data Acquisition 1 A technical evaluation process for cars is available from the Series. Part of this process is the required download of AiM Data files after each timed session (Qualifying 1 & 2, Races 1 & 2). Within 30 minutes of each timed session end, all Series Competitors MUST send the AiM Data file (.XRK) for all timed laps of that session to the secure email address (data@specmx-5.com), where data will be reviewed by AiM directly. Failure to adhere to this guideline from the Series, or having non- functioning data, may be grounds for penalty or disqualification by the Series. a. Vehicle must be equipped with current generation AiM data acquisition system (configurable in Race Studio 3) that can provide on track data to AiM race studio 3. The data acquisition system may only read the OBDII/ECU data stream. It is not permitted to alter/manipulate data to and from the ECU. The AiM system may be utilized to trigger a switch I.E., cooling fans or diff cooler pumps but must be wired via a separate analog circuit. Refer to Section 17: Electrical Equipment above for installation requirements. b. The connection at the OBDII port for the AiM system may be made in either one of two ways: 1. Through a dedicated OBDII AiM adaptor. 2. By direct wiring to the back of the OBDII port within 3” of the ODBII connector. c. Fuel pressure datalogging is required. d. Oil pressure datalogging is required. e. All cars must run the latest AIM Data Logger Spec MX-5 ECU Protocol 21. Mandatory Video Camera Cars running in Spec MX-5 must have a functioning video recorder/camera during all qualifying and race sessions as described in 9.3.11. Upon request by an SCCA official, competitors must provide their video recording/data, which may be used by the SCCA for any purpose including but not limited to rule enforcement and marketing. Failure to comply with a video request from an official, or having a non-functioning video recorder/camera may will be grounds for penalty or disqualification. 22. Parts Confiscation a. Tech officials may confiscate competitors’ parts for the purpose of verification of tech compliance. 23. Penalties Clarification – Non-Compliant Parts Level Infraction Penalty 1 Non-compliant modification to any of the spec parts, engine components, ECU/Elec- tronics or modification to the chassis. May suspend the driver (i.e. suspend) of the non- compliant Spec MX-5 from competing in SCCA events for the 12 months following the suspension. A level 1 infraction carries a $1,000 fine. 2 Non-compliant modification to the suspen- sion or drivetrain outside of level one infrac- tions: engine, fuel system, charging system, exhaust, and intake system. May suspend the driver (i.e. suspend) of the non- compliant Spec MX-5 from competing in SCCA events for the 6 months following the suspension. A level 2 infraction carries a $500 fine. 3 Use of an unauthorized or non-compliant part, engine component, ECU/Electronics or chassis or chassis part. May suspend the driver (i.e. suspend) of the non- compliant Spec MX-5 from competing in SCCA events for the 12 months following the suspension. A level 3 infraction carries a $1,000 fine 4 Non-compliance (non-modification such as incorrect part)Use of an unauthorized or non- compliant for any of the suspension or drive- train part or component outside of level one infractions: engine, fuel system, charging system, exhaust, and intake system. May suspend the driver (i.e. suspend) of the non- compliant Spec MX-5 from competing in SCCA events for the 6 months following the suspension. A level 4 infraction carries a $500 fine
neutralSM and SMX shifter bushing rules clarified: alternate bushing at shift lever bottom now allowed.
In section 9.1.7.1.D.6.3., add the following: "k. Alternate shifter bushing located at the bottom of the shift lever is allowed."
FF Update to FF EGR Blanking Plate Rule
#36633 from Matt Boian · Rule change · TB 24-10 (2024-10 Fastrack)
neutralFF VTEC activation valve must function; EGR blanking plate rule clarified with Fast Forward part numbers.
In FF, GCR section 9.1.1.B.14.r.1, change as follows: "All emission control devices must be removed and blocked off by the blanking plate provided by HPD or Fast Forward as noted below, except for the VTEC activation valve. The VTEC activation valve must be retained; and it must be functioning. No modifications are permitted. a. EGR Plate: Fast Forward PN: FF200-301. b. EGR Port Cover: Fast Forward PN: FF200-302."
fasterHP Sprite and Midget 1275cc and 1098cc Level 2 compression ratio raised to 12.0:1.
In HP Spec Lines, Austin-Healey Sprite MkI, II, III, IV MG Midget (ALL) - Level 2 - 1275cc, change Notes as follows: "(Effective 11/1/2024) Compression ratio limited to 11 12.0:1" In HP Spec Lines, Austin-Healey Sprite MkI, II, III, IV MG Midget (ALL) - Level 2 - 1098cc, change Notes as follows: "(Effective 11/1/2024) Compression ratio limited to 11 12.0:1"
FF Change FF/FC Weight with Sequential Gearbox
#36651 from Robert Wright · Rule change · TB 24-11 (2024-11 Fastrack)
fasterFF and FC cars with sequential gearbox must add 10 lbs. to minimum weight, down from 25 lbs.
In FF, GCR section 9.1.1.B.20.A.3, change as follows: "Cars running with a sequentially shifted gear box shall must add 25 10 lbs. to minimum weight." In FC, GCR section 9.1.1.B.20.B.4, change as follows: "Cars running with a sequentially shifted gear box shall must add 25 10 lbs. to minimum weight."
EP NA Miata Track Width Correction
#36902 from Production Committee · Rule change · TB 24-11 (2024-11 Fastrack)
neutralEP Mazda Miata front and rear track widths increased to 1516/1534 mm (59.7/60.4 in.) across all generations.
#37064 from Formula/Sports Racing Committee · Rule change · TB 24-11 (2024-11 Fastrack)
neutralFF Honda Fit allows Fast Forward 0.25mm oversize pistons PN FF800-110 as alternative; piston diameter spec clarified to 2.8835 inches.
In FF, GCR section 9.1.1.B.14.e.1, change as follows: "Honda Fit OEM standard size pistons, PN: 13010-RB1-000, or Honda Fit OEM 0.25mm oversize pistons, PN: 13020-RB7-Z00, or Fast Forward 0.25mm oversize pistons, PN: FF800-110, may be used." In GCR section 9.1.1.B.14.e.2, change as follows: "a. Maximum standard piston diameter, measured at a point 16mm from the bottom of the skirt: 73.240mm (2.8834 2.8835 inches). b. Centerline of wrist pin to crown maximum: 26.21mm (1.032 inches). c. Maximum overall height from skirt to crown edge: 47.80mm (1.882 inches).
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d. Minimum weight: 198.0 grams (6.984 ounces). e. Minimum weight of piston pin: 66 grams (2.25 ounces). f. Combined minimum weight of piston, piston pin and connecting rod: 543.5 grams (18.85 ounces). g. Combined minimum weight of piston, wrist pin, and circlips: 267 grams (9.418 ounces). h. Centerline of wrist pin to crown edge: 26.289mm (1.035 inches). i. Ring groove widths: Top ring groove: 1.003mm (0.0395 inches). Middle ring groove: 1.016mm (0.0400 inches). Oil ring groove: 1.981mm (0.0780 inches). j. Ring groove distance from wrist pin center to bottom of groove: Top ring groove: 19.63mm (0.7730 inches). Middle ring groove: 15.29mm (0.6020 inches). Oil ring groove: 10.91mm (0.4295 inches)."
neutralSMX allows OE instrument cluster relocation for aftermarket dash mounting, with wiring re-routed only; alternate gauges now permitted.
In GCR, Section 9.1.7.D.5.u-w, change as follows: "u. Alternate guages and instuments may be added. The original OE instrument cluster must remain unmodified, connected and functional. However, it may be relocated to allow the mounting of an aftermarket dash such as an AIM. The wiring to relocated the dash may not be cut or extended, it may only be re-routed. The remainder of teh dashboard or panel must remain intact. v. Alternate gauges and instuments may be added. w. Modifications may be made to the foot pedals to improve the comfort and accessibility to the driver; relocation of mounting points is not permitted. 1. Dead pedal/footrest and heel stop may be added.
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w. Instrument clusters must be unmodified parts."
EP Triumph GT6 Adjustments
#37112 from Anthony Parker · Rule change · TB 24-12 (2024-12 Fastrack)
slowerEP Triumph GT6 switches to three Weber 40 DCOE carbs with 28mm chokes, weight rises 50 lbs to 1990.
In EP Spec Lines, make the following changes in the "Triumph GT6" spec line: Carburetor No. & Type: (2): "1.5” 1.75" Auto-type carburetor(s)" Notes: "Two (2) 1.75” auto-type carburetors @ 1940 lbs. Three (3) Weber 40 DCOE on IR manifold with 28mm chokes @ 1990 lbs. Laycock overdrive, May use 5 speed gearbox w/o overdrive."
EP Request to Reduce Weight of BMW 325i/is E30 (84-91) Spec Line
#37119 from Tim Schreyer · Rule change · TB 25-01 (2025-01 Fastrack)
fasterEP BMW 325i/is E30 (84-91) weight reduced 50–52 lbs across three spec lines to 2150, 2204, 2258.
In EP SPEC LINES, BMW 325i/is (E30) (84-91), change Weight as follows: "2200 2150 *2255 2204 **2310 2258"
In EP Spec Lines, add to Notes as follows: BMW Z3 2.5LL "(Effective 2/21/2025) 52mm Flat Plate Intake Restrictor is required." BMW Z3 2.8L (97-00): "(Effective 2/21/2025) 55mm Flat Plate Intake Restrictor is required." BMW 328i/is E36 (96-99): "(Effective 2/21/2025) 58mm Flat Plate Intake Restrictor is required." BMW 328i/ci E46 (01-06): "(Effective 2/21/2025) 58mm Flat Plate Intake Restrictor is required." BMW 325i/is E46 (01-06): "(Effective 2/21/2025) 56mm Flat Plate Intake Restrictor is required." BMW 325i/is E-36 (92-95): "(Effective 2/21/2025) 56mm Flat Plate Intake Restrictor is required." BMW 325is M-Technic (1994): "(Effective 2/21/2025) 56mm Flat Plate Intake Restrictor is required."
Cal Club 2025 → Cal Club 2026 2025-02-22 to 2026-02-21
EP Request Competition Adjustment to BMW Z3 2.5L
#37120 from Tim Schreyer · Rule change · TB 25-01 (2025-01 Fastrack)
slowerEP BMW Z3 and 3-series models get smaller intake restrictors: Z3 2.5L to 52mm, Z3 2.8L to 55mm, 328i to 58mm, 325i to 56mm.
In EP Spec Lines, change Notes as follows: BMW Z3 2.5LL "(Effective 3/1/2025) 56mm 52mm Flat Plate Intake Restrictor is required." BMW Z3 2.8L (97-00): "(Effective 3/1/2025) 59mm 55mm Flat Plate Intake Restrictor is required." BMW 328i/is E36 (96-99): "(Effective 3/1/2025) 62mm 58mm Flat Plate Intake Restrictor is required." BMW 328i/ci E46 (01-06): "(Effective 3/1/2025) 62mm 58mm Flat Plate Intake Restrictor is required." BMW 325i/is E46 (01-06): "(Effective 3/1/2025) 60mm 56mm Flat Plate Intake Restrictor is required." BMW 325i/is E-36 (92-95): "(Effective 3/1/2025) 60mm 56mm Flat Plate Intake Restrictor is required." BMW 325is M-Technic (1994): "(Effective 3/1/2025) 60mm 56mm Flat Plate Intake Restrictor is required."
EP Interpretation of Production Rules on Mirrors
#37235 from Lawrence Slivinski · Rule change · TB 25-03 (2025-03 Fastrack)
neutralEP, FP, HP: interior or exterior mirrors meeting rule 9.3.36 now permitted.
In GCR, add new rule as Section 9.1.5.E.10.f: "Any interior or exterior mirror(s) that meets rule 9.3.36 may be used."
EP Weight Reduction for Honda S2000
#37466 from Michael Unger · Rule change · TB 25-03 (2025-03 Fastrack)
fasterEP Honda S2000 1997cc base loses 75 lbs to 2375; 2157cc base loses 60 lbs to 2450.
In EP, Spec Lines make the following weight changes:
A specification table follows in the original; it is not shown here.
EP Mazda 1999 Miata 1.8L
#37488 from Joe Carr · Rule change · TB 25-03 (2025-03 Fastrack)
fasterEP Mazda MX-5/Miata 99-05 minimum weight drops to 2100 lbs, 2153 lbs with power adder, 2205 lbs with two adders.
In EP Spec Lines, make the following weight change: Mazda MX-5 /Miata (99-05): "2150 2100 *2204 2153 **2258 2205"
FF Formula F Proposal to Invite Older Cars Via a Tire Rule Change
#37802 from Anthony Stefanelli · Rule change · TB 25-03 (2025-03 Fastrack)
fasterFF allows older cars with rocker arm or outboard suspension to use bias ply slicks or VFF tires instead of radials.
In FF, GCR section 9.1.1.B.10.e, change as follows: "Formula F shall be limited to the following tires (front tires may not be used as rears): Dries: Front - Hoosier R60A Radial 43322 or F1600 Radial 43321 185/60R13 Rear - Hoosier R60A Radial 43327 or F1600 Radial 43326 205/60R13 Wets: Front - Hoosier Wet or W3 Radial 44421 185/60R13 Rear - Hoosier Wet or W3 Radial 44426 205/60R13
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Alternatively, Formula F cars with rocker arm suspension (e.g., Swift DB1, 1987-90 Reynard) and/or outboard suspension on at least one chassis end may use the following tires: Dries: Front - Hoosier H43130 R60A 20.0 x 6.0-13 or H43164 R60A 20.5 x 7.0-13 bias ply slick Rear – Hoosier H43307 R60A 22.5 x 7.2-13 bias ply slick Wets: Radial wets listed above or Front - Hoosier 44165 135/545-13 VFF Rear - Hoosier 44170 165/580-13 VFF Front tires may not be used as rears, and tires may not be mixed, i.e., radial tires may not be mixed with bias ply slick tires, bias ply slick tires may not be mixed with VFF tires, and radial tires may not be mixed with VFF tires."
EP Request for Classification of Chevrolet Spark
#37755 from Kristian Smith · Rule change · TB 25-04 (2025-04 Fastrack)
neutralChevrolet Spark 16-22 classified HP Pre at 1850 lbs minimum weight, fuel injected, 1399 cc.
In HP Spec Lines, classify the Chevrolet Spark (16-22):
A specification table follows in the original; it is not shown here.
EP Request to Lower Ford Festiva Minimum Weight to 1600 LBS
fasterHP Ford Festiva 88-93 minimum weight drops to 1600 lbs, variants to 1640 and 1680 lbs; compression ratio raised to 11.0:1.
In HP Spec Lines "Ford Festiva (88-93)" change as follows: Weight: "1700 1600 *1743 1640 **1785 1680" Notes: "Compression ratio limited to 10.5 11.0:1. Valve lift limited to .450”."
neutralSMX Toyo RR P235/40/ZR17 tire rules clarified: one set per weekend, marking after first session, damage replacement procedures revised.
In GCR, Section 9.1.7.1.D.16.c., change as follows: "1. Cars in SMX are limited to running 1 (one) new (sticker) set, used tires or any of those combinations, of class specified Toyo tires (Toyo RR P235/40/ZR17) per regular season Hoosier Super Tour event weekend during qualifying and races (not including any test day sessions). Before the first dry qualifying or race (if rain in qualifying) session competitors will supply four Toyo RR P235/40/ZR17 tires for marking to use during the entire weekend. Class specified rain tires will not be marked. SMX cars are limited to one set of Toyo RR P235/40/ZR17 per Hoosier Super Tour event weekend for all dry qualifying and race sessions. This limitation does not include testing or practice sessions. Approved rain tires will not be required to be marked. 2. A mandatory impound for all SMX competitors is required after the first dry qualifying or race (if rain in qualifying) session. It
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is the competitor’s responsibility to ensure their tires are marked prior to going on track for the next session. A mandatory impound for all SMX competitors will occur after the first dry qualifying or race session. All tires will be marked for the remainder of the race weekend. It is the competitor’s responsibility to report to impound and ensure their tires are marked prior to leaving impound. 3. If a competitor damages a tire or wheel, and there is a safety concern, the competitor must find the Hoosier Super Tour Series Tech Chief or SMX CCC, if assigned, for inspection. At the direction of the Hoosier Super Tour Series Tech Chief or SMX CCC, the compet- itor will be allowed to substitute alternate used tire(s) to replace the damaged tire(s). New tires are not an option as a replacement tire for a damaged tire. If a competitor damages a tire or wheel and there is a safety concern, the competitor must find the Hooseir Super Tour Series Tech Chief or SMX CCC, if assigned, for inspection. At the discretion of the Hoosier Super Tour Series Tech Chief of SMX CCC the competitor may be allowed to substitute alternate used tires(s) to replace the damaged tire(s). New tires are not an option as a replacement tire for a damaged tire."
SMX SMX Data Submission Timeframe
#38039 from Jason Fichter · Rule change · TB 25-05 (2025-05 Fastrack)
neutralSMX data submission deadline extended from 30 to 60 minutes after each timed session.
RM 25-04 Please update the data acquisition timeframe in GCR section 9.1.7.1.D.20 "20. Data Acquisition 1. A technical evaluation process for cars is available. Part of this process is the required download of AiM Data files after each timed session (Qualifying 1 & 2, Races 1 & 2). Within 30 60 minutes of each timed session end, all competitors MUST send the AiM Data file (.XRK) for all timed laps of that session to the secure email address (data@specmx-5.com), where data will be reviewed by AiM directly. Failure to adhere to this guideline, or having non-functioning data, may be grounds for penalty or disqualification."
FF Page 228, FF tire rule 9.1.1.10.e
#38251 from Anthony Stefanelli · Rule change · TB 25-05 (2025-05 Fastrack)
neutralFF adds rocker arm and outboard suspension cars optional bias ply and VFF tires; removes front-as-rear rule, adds mixing restrictions.
In FF, GCR section 9.1.1.B.10.e, change as follows: "Formula F shall be limited to the following tires (front tires may not be used as rears): Dries: Front - Hoosier R60A Radial 43322 or F1600 Radial 43321 185/60R13 Rear - Hoosier R60A Radial 43327 or F1600 Radial 43326 205/60R13 Wets: Front - Hoosier Wet or W3 Radial 44421 185/60R13 Rear - Hoosier Wet or W3 Radial 44426 205/60R13
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Alternatively, Formula F cars with rocker arm suspension (e.g., Swift DB1, 1987-90 Reynard) and/or outboard suspension on at least one chassis end may use the following tires: Dries: Front - Hoosier H43130 R60A 20.0 x 6.0-13 or H43164 R60A 20.5 x 7.0-13 bias ply slick or Hoosier 44165 135/545-13 VFF Rear – Hoosier H43307 R60A 22.5 x 7.2-13 bias ply slick or Hoosier 44170 165/580-13 VFF Wets: Radial wets or VFF tires listed above or Front - Hoosier 44165 135/545-13 VFF Rear - Hoosier 44170 165/580-13 VFF Front tires may not be used as rears, and tires may not be mixed, i.e., radial tires may not be mixed with bias ply slick tires, bias ply slick tires may not be mixed with VFF tires, and radial tires may not be mixed with VFF tires."
neutralSMX drivers must submit data acquisition files on time or face suspension and $250 fine.
In GCR, Section 9.1.7.1.23 add new level 5 infraction as follows: Level: "5" Infraction: "Failure to successfully submit (received by data@specmx-5.com) data acquisition file to data@specmx-5 per the timeframes outlined in GCR section 9.1.7.1.20." Penalty: "May suspend the driver (i.e. suspend) of the Spec MX-5 that failed to submit data on time or at all from competing in SCCA events for the 3 months following the suspension. A level 5 infraction may carry a $250.00 fine."
EP Base Weight Adjustment for H-Production X1/9 Spec Lines
#38255 from Matthew Brannon · Rule change · TB 25-06 (2025-06 Fastrack)
fasterHP Fiat X-1/9 base weights reduced 50–53 lbs across 1300 and 1500 spec lines.
In HP Spec Lines, change Weight as follows: Fiat X-1/9 & Bertone1500: “1790 1740 *1835 1784 **1880 1827” Fiat X-1/9 1300: “1650 1600 *1691 1640 **1733 1680” Fiat X-1/9 1300: “2060 2010” Fiat X-1/9 1500: “1950 1900”
SMX Committee) SMX Penaly Clarification updated language
neutralSMX penalty language clarified: level 1 and 3 infractions may carry $1,000 fine; level 2 and 4 may carry $500 fine.
In GCR, Section 9.1.7.1.23. change as follows: Rename as follows: "Penalties Clarification – Non-Compliant Parts SMX Penalty Guidelines" Change the Penalty language for level 1 to the following: "A level 1 infraction carries may carry a $1,000 fine." Change the penalty language for level 2 to the following: "A level 2 infraction carries may carry a $500 fine." Change the penalty language for level 3 to the following: "A level 3 infraction carries may carry a $1,000 fine." Change the penalty language for level 4 to the following: "A level 4 infraction carries may carry a $500 fine."
slowerEP BMW Z4 03-05 restricted to 52mm flat plate intake restrictor.
In EP Spec Lines, BMW Z4 (03-05), add to Notes the following: “52mm Flat Plate Intake Restrictor.”
EP EP Fiat 124 Spider Competition Adjustment Request
#38498 from John Baucom · Rule change · TB 25-07 (2025-07 Fastrack)
fasterEP Fiat 124 Spider 1600 & 2000 weight drops 50 lbs to 2000; carburetors gain 2mm chokes to 36mm.
In EP Spec Lines, Fiat 124 Sport Spider 1600 & 124 Spider 2000, change as follows: Weight: "2050 2000" Carburetor No. & Type: "(2) Weber 40 IDF-40IFI, (2) Solex C40P116, 34 36mm choke(s) req’d, (2) Weber 45DCOE w/ 34 36 mm choke(s) on I.R. manifold or fuel injection."
EP HP Plymouth Arrow spec omission
#38995 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)
neutralHP Plymouth Arrow transmission max speeds clarified to 4 or 5.
In HP Spec Lines, Plymouth Arrow (76-80), add the following wording to Trans. Speeds(max): "4 or 5"
EP Add Wheel Diameter to Appendix G
#39008 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)
neutralEP, FP, HP wheel diameter added to Appendix G as absolute maximum specification.
In Appendix G.2.3, change as follows: "Rim width and diameter are is absolute maximums."
EP Add TB ID tolerance to general Prod rules
#39009 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)
neutralEP, FP, HP throttle body inside dimensions must remain stock with +/-.25mm tolerance; butterfly dimensions stock in FP, HP only.
In GCR, Section 9.1.5.E., change as follows: 9.1.5.E.1.b.4: "The inside dimensions of the throttle body casting/housing (as measured at the throttle butterfly) must remain stock (tolerance of +/-.25mm), but the throttle body can otherwise be ported and polished." 9.1.5.E.2.b.4: "The inside dimensions of the throttle body casting/housing and all dimensions of the throttle butterfly must remain stock (tolerance of +/-.25mm)."
EP Please Lower Weight of 280Z
#38871 from Matthew Miller · Rule change · TB 25-09 (2025-09 Fastrack)
fasterEP Nissan 280Z minimum weight reduced from 2560 to 2400 lbs.
In EP Spec Lines, Nissan 280Z, change Weight (lbs) as follows: "(Effective 11/1/2025) 2560 2400 *2624 2460 **2688 2520"
EP Miata Weight Adjustment Follow Up
#38949 from Don Tucker · Rule change · TB 25-10 (2025-10 Fastrack)
fasterEP Mazda MX-5 1.8L 90-97 weight reduced to 2125 lbs from 2150 lbs.
In EP Spec Lines, Mazda MX-5 / Miata 1.8L (90-97), Effective 11/1/2025 make the following weight change: "2150 2125"
EP Weight Break for 1098 Midget / Sprite
#38970 from Kendall Jones · Rule change · TB 25-10 (2025-10 Fastrack)
In HP Spec Lines, Austin-Healey Sprite/Midget 1098cc, Effective 11/1/2025make the following weight change: "1630 1550"
EP HP Volvo 142 spec omission
#38994 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)
slowerHP Volvo 142/142E gains compression ratio limit 12.0:1 and valve lift limit .425".
In HP Spec Lines, Volvo 142/142E P-1800 Engine, Effective 11/1/2025 add the following wording to Notes: "Comp. Ratio limited to 12.0:1. Valve lift limited to .425”."
EP HP Mini DOHC 1.6
#38996 from Production Committee · Rule change · TB 25-10 (2025-10 Fastrack)
slowerHP Mini Cooper 07-15 valve lift reduced to .390", from .450".
In HP Spec Lines, Mini Cooper (07-13) (includes 09-15 convertible and 12-15 Coupe), Effective 11/1/2025 make the following changes to the Notes: "Compression ratio limited to 11.0:1, Valve lift limited to .450”.390"."
EP Add to Rabbit description
#39019 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)
neutralFP and HP Volkswagen Rabbit descriptions updated: Convertible changed to Cabriolet in FP; Cabriolet added to three HP engine variants.
In FP Spec Lines, make the following spec line correction: "Volkswagen Rabbit (Includes Convertible Cabriolet)" In HP Spec Lines, make the following spec line correction: "Volkswagen Rabbit 1588 (Includes Cabriolet)" "Volkswagen Rabbit 1715 (Includes Cabriolet)" "Volkswagen Rabbit 1780 (Includes Cabriolet)"
EP Clean-up 9.1.5.E.7e
#39025 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)
neutralEP, FP, HP: rear drum brake to disc conversion clarified; rotors solid, diameter limited to largest front rotor permitted.
In GCR, Section 9.1.5.E.7., change as follows: "e. Cars fitted with rear drum brakes, can convert to rear disc brakes without penalty. Note that the “Brakes Std.” and “Brakes Alt.” listings on a vehicle’s spec line do not prohibit a car that was fitted with rear drum brakes stock, from converting to rear disc brakes under this rule. When converting from rear drum brakes to rear disc brakes: 1. Rear brake rotors must be solid and can be no larger in diameter than the largest permitted front brake rotor, as defined on the vehicle’s spec line. 2. Rear calipers and mounting brackets are unrestricted but must be made of a ferrous or aluminum material. The standard and alternate brake listings on a vehicle’s specification line, does not prohibit a car that was fitted with rear drum brakes as stock
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from converting to rear disc brakes under this rule. 3. The “Brakes Std.” and “Brakes Alt.” listings on a vehicle’s spec line do not prohibit a car that was fitted with rear drum brakes as stock from converting to rear disc brakes under this rule."
EP Add TB size to Ford Mustang (94-98) Spec Line
#39130 from Production Committee · Rule change · TB 25-11 (2025-11 Fastrack)
neutralEP Ford Mustang (94-98) fuel injected throttle body inside diameter specified at 60.
In EP Spec Lines, Ford Mustang (94-98) add the following to the Fuel Injected Equipped Throttle Body Inside Diameter column: "60"
EP TR2 Notes E&O
#39180 from Anthony Parker · Rule change · TB 25-12 (2025-12 Fastrack)
unclearEP Triumph TR2-TR4A allows 5-speed gearbox without overdrive; removes Weber carb and weight specification.
In EP Spec Lines, Triumph TR2, 3, 3A, 4, 4A, TR4, TR4A, IRS, make the following change to the Notes: "Front apron assembly may be made of alternate material. Three (3) Weber 40 DCOE on IR manifold with 28mm chokes @ 1990 lbs. Laycock overdrive, may use 5 speed gearbox without overdrive."
EP Balance of Power
#39187 from Jim Simaras · Rule change · TB 25-12 (2025-12 Fastrack)
slowerEP BMW Z3 2.5L restrictor reduced 52mm to 50mm, weight increased to 2550 lbs base; five other BMW models get smaller restrictors.
In EP Spec Lines, make the following changes to Restrictors: BMW Z3 2.5L: "52mm 50mm Flat Plate Intake Restrictor" BMW Z3 2.8L (97-00): "55mm 53mm Flat Plate Intake Restrictor" BMW 328i/is E36 (96-99): "58mm 55mm Flat Plate Intake Restrictor" BMW 328i/ci E46 (01-06): "58mm 55mm Flat Plate Intake Restrictor" BMW 325i/is (E46) (01-06): "56mm 53mm Flat Plate Intake Restrictor" BMW 325is M-Technic (1994): "56mm 53mm Flat Plate Intake Restrictor" BMW 325i/is E-36 (92-95): "56mm 53mm Flat Plate Intake Restrictor"
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In EP Spec Lines, BMW Z3 2.5L, change Weight as follows: "2500 2550 *2563 2614 **2625 2678"
FF Formula F Alternative Tire Rule Proposed Clarifications
#39281 from Jay Messenger · Rule change · TB 26-01 (2026-01 Fastrack)
neutralFF clarifies alternative tire eligibility for cars homologated 1989 or earlier with rocker arm or outboard suspension on all four corners.
In FF, GCR section 9.1.1.B.10.e, change as follows: "Alternatively, Formula F cars with rocker arm suspension (e.g., 1987-90 Reynard, Swift DB1,) and/or outboard suspension on at least one chassis end homologated in 1989 or earlier with any combination of rocker arm or outboard suspension on all four corners (e.g., 1987 – 1990 Reynard, Swift DB1) may use the following alternative tires. Note: This rule is intended to allow older cars with the described suspension design to use the alternative tires. It is not to be exploited by modifying cars with push-rods or pull-rods to meet the above requirements or by modifying either end of older cars to push- or pull-rod suspension to be eligible to run the alternative tires. Cars that were homologated in 1989 or earlier with push- or pull-rod suspension on no more than two corners may seek approval to run the alternative tire by utilizing the compliance process outlined in GCR section 8.1.4."
EP Request to Update E30 BMW Throttle Body Diameter Verbiage
#39363 from Tim Schreyer · Rule change · TB 26-01 (2026-01 Fastrack)
neutralEP BMW 325i/is E30 throttle body specified as 60mm in fuel injection notes.
In EP Spec Line BMW 325i/is E30 (84-91), change Drivetrain Notes as follows: "Fuel Injection, TB: 60mm"
What the rules allowed changed as listed; this does not say what any particular car ran.