STL at Mid-Ohio Sports Car Course

2019-01-01 STL Request to equalize FPR Reduction on all B-Series Vtec Engines

#24746 from Eric Kutil · Rule change · TB 19-01 (2019-01 Fastrack)

In STL, Table A, Acura/Honda B17, add to the notes as follows:
“54mm flat Plate restrictor required.”
In STL, Table A, Acura/HondaB18C(JDM Type R),B18C5(USDM Type R),B18C6(UK and Euro
Type R),B18C7(Australia Type R), make changes to weight and notes as follows:
“Chart + 2% Chart”
“Effective 03/01/2018, 53 54mm flat plate restrictor required.”

2019-01-01 STL Request E&O for Mazda Miata Spec Line

#25955 from SCCA Staff · Rule change · TB 19-01 (2019-01 Fastrack)

In STL, Mazda Miata, delete the maximum displacement (cc’s) and correct the minimum
weight as follows:

2019-03-01 STL Request to Allow VW 1.8L Engine

#25614 from Cameron Conover · Rule change · TB 19-03 (2019-03 Fastrack)

In STL, classify the VW 20V 1.8 in Table B as follows:
STL Maximum
Displacement (cc’s) Minimum Weight Notes
VW 1.8L R4 20VT 1781 Chart Engine Permitted with turbocharger removed.
Must meet all other STL specifications

2019-03-01 STL Request to reduce weight of RX8 with Renesis rotary

#25781 from DAVID MEAD · Rule change · TB 19-03 (2019-03 Fastrack)

In STL, Mazda Renesis, change the weight as follows:
“2800 2700”

2019-03-01 STL Request for Open Brake Pads On Mazda MX-5 Cup NC

#25821 from Tyler Quance · Rule change · TB 19-03 (2019-03 Fastrack)

In STL, Mazda MX-5 Cup, add to the notes as follows:
“Tires per STL regulations. Brake pad compound are open.”

2019-03-01 STL Request to clarify B18C1 GSR Honda B motor table

#26209 from Mike Taylor · Rule change · TB 19-03 (2019-03 Fastrack)

In STL, add Acura/Honda B18C1 to Table A as follows:
STL Maximum
Displacement (cc’s)
Minimum
Weight Notes
Acura/Honda
B18C1
Acura/Honda

2019-03-01 STL Port Matching

#26415 from Super Touring Committee · Rule change · TB 19-03 (2019-03 Fastrack)

In STL, Mazda 12, table A, strike the wording in the notes as follows:
“No porting or port matching is permitted.”
In STL, Mazda 13B, table A, strike the wording in the notes as follows:
“No porting or port matching is permitted.”

2019-05-01 STL Request Ride Height Clarification

#26597 from SCCA Staff · Rule change · TB 19-05 (2019-05 Fastrack)

In GCR Appendix K.F.5, add as follows:
“Ride height will be measured without driver at the lowest point of the rocker panel, not
including the pinch weld.”
In GCR section 9.1.4.F.5, add as follows:
“Ride height will be measured without driver at the lowest point of the rocker panel, not
including the pinch weld.”

2019-05-31 STL Request Restrictor Plate correction

#26779 from Jose De Miguel · Rule change · TB 19-06 (2019-06 Fastrack)

9.1.4.2 Table A, Acura/Honda B18 (except C engine), make changes to notes as follows:
"53 54mm flat plate restrictor required."

2019-07-01 STL Request clarification for manifold and throttle in STU

#27004 from Jose De Miguel · Rule change · TB 19-07 (2019-07 Fastrack)

In STU, GCR section 9.1.4.1.B.3, make changes as follows:
"All cars shall use the installed engine’s or vehicle's stock air throttling device (e.g.,
throttle body, carburetor) and intake manifold, unless noted otherwise. Alternate intake
manifolds will be permitted on a case-by-case basis."

2019-10-01 STL Request to Classify Spec MX-5 Challenge in STL

#27399 from Josh Smith · Rule change · TB 19-10 (2019-10 Fastrack)

In STL, classify the Mazda Spec MX5 Challenge as follows:

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

2020-03-01 STL Request to add wheel part numbers

#28342 from SCCA Staff · Rule change · TB 20-03 (2020-03 Fastrack)

In STL, Mazda Spec MX5 Challenge, add wheel part numbers to the notes as follows:
"0000-04-5706-GM, 0000-04-5706-SL"

2020-04-01 STL Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0

#27884 from David Mead · Rule change · TB 20-04 (2020-04 Fastrack)

In STU, GM Ecotech LNF Spec Lines, add to Notes as follows:
“LNF Engine Permitted with turbocharger removed. LNF Engine short block with LE5 cylinder head and
intake manifold permitted. Must meet all other STL specifications.”

2020-04-01 STL Acura/Honda B18C engine chart. Reduce the current 54 mm flat plat

#28663 from Club Racing Board · Rule change · TB 20-04 (2020-04 Fastrack)

In STL, Mazda MZR Table A, change the restrictor size in the notes as follows:
"54 53mm"

2020-04-01 STL Mazda MZR engine chart. Reduce the current 55 mm flat plate to 53

#28664 from Club Racing Board · Rule change · TB 20-04 (2020-04 Fastrack)

In STL, Mazda MZR Table A, change the restrictor size in the notes as follows:
"55 53mm"

2020-05-01 STL STL Honda B18 restrictor changes

#28794 from Club Racing Board · Rule change · TB 20-05 (2019-05 Fastrack)

In STL Spec Lines, Honda B18, change as follows:
"53mm flat plate restrictor required."
In STL Spec Lines, change as follows:
"Acura/Honda B18C (JDM Type R), B18C1, B18C5 (USDM Type R), B18C6 (UK and Euro Type R), B18C7
(Australia Type R)"
In STL Spec Lines, Acura/Honda B18C (JDM Type R), B18C5 (USDM Type R), B18C6 (UK and Euro Type R),
B18C7 (Australia Type R), change notes as follows:
"Any porting and or polishing of intake and or exhaust ports outside of the 1” port matching allowance,

2020-06-01 STL Request to add 2016-2019 GMX-5 Spec line

#28604 from Josh Smith · Rule change · TB 20-06 (2020-06 Fastrack)

In STL, classify the Mazda MX-5 Global Cup (16-18) as follows:
STL Maximum
Displacement (cc's) Minimum Weight Notes
Mazda MX-5
Global Cup
(16-18)
2000 2450 Must meet all MX-5 Global Cup
rules. Any OEM or aftermarket

2020-06-01 STL Request to update PN for MX-5

#28622 from SCCA Staff · Rule change · TB 20-06 (2020-06 Fastrack)

In STL, Mazda MX-5 / Club Model (06-15), make changes as follows:
"Allow Mazda header part number 0000-06-5407-NC."

2020-06-01 STL Correction - Clarification Honda/Acura B18B engine Letter # 26209

#28873 from Club Racing Board · Rule change · TB 20-06 (2020-06 Fastrack)

In STL, Table A, Acura/Honda B18 (except C engine) change as follows:
"Acura/Honda B18 (except C1 engine)"
In STL, Table A, Acura/Honda B18 (except C engine) change Notes as follows:
"53 54mm"
In STL, Table A, Acura/Honda B18C (JDM Type R), B18C1, B18C5 (USDM Type R), B18C6 (UK and Euro
Type R), B18C7 (Australia Type R) change as follows:
"Acura/Honda B18C (JDM Type R), B18C1, B18C5 (USDM Type R), B18C6 (UK and Euro Type R), B18C7
(Australia Type R)"

2020-07-01 STL Request for Addition to GT3 Approved Turbo List

#27576 from Chris Edens · Rule change · TB 20-07 (2020-08 Fastrack)

In GT3, GCR section 9.1.2.F.7.h.6., add turbocharger as follows:
"d. Borg-Warner EFR6258"
In STU, GCR section 9.1.4.1.H.5, add turbocharger as follows:
"- Borg-Warner EFR6258"

2020-08-01 STL Minimum Weight Determination

#27695 from David Fiorelli · Rule change · TB 20-08 (2020-08 Fastrack)

In STU, GCR section 9.1.4.10., add the following:
"All weight adjustments for engines shall be applied first, then that total is to be used as the baseline for
any chassis-related weight adjustments. Chassis related adjustment that are percentage based are
performed by adding specified percent first and subtracting specified percentage second if necessary.
Final step is addition or subtraction of specified weight in pounds."
In STL, GCR Section 9.1.4.4., add the following:
"All weight adjustments for engines shall be applied first, then that total is to be used as the baseline for
any chassis-related weight adjustments. Chassis related adjustment that are percentage based are

2020-08-01 STL ST Gurney flap Wicker clarification

#29012 from SCCA Staff · Rule change · TB 20-08 (2020-08 Fastrack)

In GCR section 9.1.4.D.4, clarify wording as follows:
"d. Wings shall be a single element with a maximum chord length of 8.50 inches, including
any wicker Gurney flap."
"f. The entire rear wing assembly, including the end plates and any wicker Gurney flap, shall be mounted
a minimum of 6.0 inches below the peak of the roof or roll cage main hoop whichever is higher,
measured at the highest point. Cars with a wagonback/notchback/hatchback style body may have the
rear wing assembly, including the end plates and any wicker Gurney flap, mounted a maximum of
4.0inches above the highest point of the roof."

2020-12-01 STL Request clarification on wing measurement

#29640 from Jose De Miguel · Rule change · TB 20-12 (2020-12 Fastrack)

IN ST, GCR Section 9.1.4.D.4.e, add the following:
"Unless otherwise specified in the applicable rules the measurement of aero dynamic devices and reference areas shall include
end plates but not include fasteners as long as the fasteners serve no other purpose. Fasteners may protrude no more than 1/2”
from the mounting surface."

2021-01-01 STL Request for FWD and RWD Parity

#29728 from Tom Fowler · Rule change · TB 21-01 (2021-01 Fastrack)

In STL, GCR Section 9.1.4.2.H.2, change as follows:
"Rear wheel drive cars with strut front suspension must add 3 0.5 percent to their baseline STL weight. All other rear wheel drive
cars must add 5.5 2.5 percent to their standard baseline STL weight."

2021-01-01 STL Request to Remove Honda F20C 2% Weight Penalty

#29815 from David Mead · Rule change · TB 21-01 (2021-01 Fastrack)

In STL Spec Lines, Honda F20C, change Minimum Weight as follows:
"Chart + 2%"

2021-01-01 STL Request for FWD and RWD Parity

#30023 from Club Racing Board · Rule change · TB 21-01 (2021-01 Fastrack)

In STL, Table A, Acura/Honda B16, change Notes as follows:
"54 53mm flat plate restrictor required."
In STL, Table A, Acura/Honda B17, change Notes as follows:
"54 53mm flat plate restrictor required."
In STL, Table A, Acura/Honda B18C1, change Notes as follows:
"54 53mm flat plate restrictor required."
In STL, Table A, Acura/Honda B18C (JDM Type R), B18C5 (USDM Type R), B18C6 (UK and Euro Type R), B18C7 (Australia Type R),
change Notes as follows:

2021-02-01 STL Brake Component Relocation

#29990 from Christopher Childs · Rule change · TB 21-02 (2021-02 Fastrack)

In ST, Section 9.1.4.N.1., add the following:
"ABS actuation hardware and wiring may be relocated anywhere within the engine compartment."

2021-02-01 STL Super Touring Wing Clarification

#30111 from Greg Maloy · Rule change · TB 21-02 (2021-02 Fastrack)

In GCR, Section 9.1.4.D.g, change as follows:
"The trailing edge of the rear wing, including end plates and gurney flap, may be mounted no further rearward than the center
of the rearmost part approved bodywork."

2021-02-01 STL Transmission Options

#30118 from John Warren · Rule change · TB 21-02 (2021-02 Fastrack)

In STL, Section 9.4.1.2.C.2, change as follows:
"Either the original transmission or an alternate transmission must be used; the alternate transmission must be from the same
manufacturer as the vehicle (i.e., an Acura transmission may be installed in a Honda car). Alternate transmissions must be used
in their entirety; any OEM gear sets (drive and driven gear pairs) that fit w/o any modifications to gears, shafts, and/or case are
permitted. Modifications to input shafts for fitment are allowed."

2021-03-01 STL GM Ecotec engines in STL

#30247 from Tim DeRonne · Rule change · TB 21-03 (2021-03 Fastrack)

In STL, Table B, change GM Ecotech LNF, as follows:
"GM Ecotech LNF"
In STL, Table B, GM Ecotech LNF, add to Notes as follows:
"Any combination of GM Ecotech engine family permitted. Must use 55mm flat plate restrictor. Must meet all other STL
specifications."

2021-03-01 STL Super Touring Alternate Miata Hubs

#30345 from Club Racing Board · Rule change · TB 21-03 (2021-03 Fastrack)

In ST, GCR section 9.1.4.M, add alternate front wheel hubs as follows:
"18. Allow alternate front wheel front hubs for the 90-05 Mazda Miata:
Mazda Motorsports Development Part #0000-04-5HUB-S1"

2021-04-01 STL ST Oil Coolers E&O Correction to 9.1.4.2.H

#30388 from Philip Royle · Rule change · TB 21-04 (2021-04 Fastrack)

In ST, section 9.1.4.G.14, change as follows:
"Vents, breathers, and oil filters and oil coolers may be added, or substituted. All emission control devices may be removed and
the resulting holes plugged."

2021-05-01 STL Solstice Ride Height

#30183 from Tim DeRonne · Rule change · TB 21-05 (2021-05 Fastrack)

In STL Table B, Pontiac Solstice/SaturnSky, add to notes as follows:
"4" ride height allowed."

2021-05-01 STL Request Mazda B5 DOHC

#30420 from Derrick Ambrose · Rule change · TB 21-05 (2021-05 Fastrack)

In STL Table A, classify Mazda B5 DOHC as follows:
STL Maximum Displacement (cc's) Minimum Weight Notes
Mazda B5 DOHC Chart Must meet ALL STL regulations.

2021-05-01 STL Honda B16A (JDM) Restrictor change

#30531 from Club Racing Board · Rule change · TB 21-05 (2021-05 Fastrack)

In STL Table B, Honda B16A (JDM), change notes as follows:
"54 53mm"

2021-06-01 STL VW Engine Request

#30625 from PABLO GASTALDI · Rule change · TB 21-06 (2021-06 Fastrack)

In STL Spec Lines, classify Volkswagen 2.0L TFSI, as follows:
STL Maximum Displacement
(cc's) Minimum Weight Notes
Volkswagen 2.0 TFSI 1984 Chart Engine Permitted with turbocharger
removed. Must meet all other STL
specifications.

2021-09-01 STL Request to clean up Spec MX-5 Redundancy

#31069 from SCCA Staff · Rule change · TB 21-09 (2021-09 Fastrack)

In STL, Mazda Spec MX-5, remove redundant spec line as follows:
"Mazda Spec MX-5. 2000cc. 2600lbs. Must Comply with 2014 SCCA Spec MX-5 Regulations."

2022-01-01 STL Throttling Device Clarification

#31323 from Jose de Miguel · Rule change · TB 22-01 (2022-01 Fastrack)

In GCR, Section 9.1.4.1.B.4., change as follows:
"The intake and exhaust porting on piston engines is free. Porting of intake manifolds and cylinder heads is free on piston
engines."

2022-01-01 STL Mazda Renesis Restriction

#31467 from Christopher Childs · Rule change · TB 22-01 (2022-01 Fastrack)

In STL Spec Lines, Mazda Renesis, change Notes as follows:
"55 60mm flat plate restrictor required."

2022-01-01 STL Clarification of 79-85 RX7 Spec line

#31621 from Daniel Sheppard · Rule change · TB 22-01 (2022-01 Fastrack)

In STL, Mazda RX-7 12A (79-85), change notes as follows:
"Stock Nikki 4 bbl carburetor on a stock manifold only. Allow the standard removal of emissions related components, and allow
air and fuel jets to be corrected. Modification of the water jacket in the area of the spark plug for cooling purposes is permitted."

2022-03-01 STL Single TB Weight Modifiers

#31449 from John Weisberg · Rule change · TB 22-03 (2022-03 Fastrack)

Effective 5.1.2022 In STU, GCR Section 9.1.4.H.1., change as follows:
"1. Minimum weights for cars with normally aspirated piston engines will be determined by 1.1 lbs/cc displacement for the
installed engine (see following table) the following table. Displacement is the stock displacement for the installed engine. For the
purpose of weight assignment, engine displacement will be rounded to the nearest 50cc (e.g., 2176cc = 2200cc and 2175cc =
2150cc)."
Factory Engine Displacement (cc) Minimum Weight (lbs)

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

2022-03-01 STL Improved Touring Tires

#32063 from Greg Amy · Rule change · TB 22-03 (2022-03 Fastrack)

In STU Table B, Improved Touring Vehicles (1985-), change Notes as follows:
"Must completely conform to ITCS requirements. Tires must conform to 9.1.4, Tires & Wheels"
In STL Table B, ITA-spec and ITS-spec RX7, change Notes as follows:
"Must completely conform to ITCS requirements. Tires must conform to 9.1.4, Tires & Wheels"
In STL Table B, ITS, ITA, ITB, or ITC vehicles (1985- ), change Notes as follows:
"Must completely conform to ITCS requirements. Tires must conform to 9.1.4, Tires & Wheels"

2023-01-01 STL Spec MX5 in STL

#33473 from Tom Bogar · Rule change · TB 23-01 (2023-01 Fastrack)

In STL, Table B: Alternate Vehicle and Engine Allowances, Mazda Spec MX5 Challenge, change notes as follows:
"ACT clutch 0000-02-5004-G6, wheels 17x8 #0000-04-5706-GM, # 0000-04- 5706-SL, and Toyo RR 235-40-17 dry, Toyo RA1 235-
40-17 wet. Alternative tires on 17x7 wheels per STL rules. No other Super Touring modifications or allowances permitted except
as noted in this spec line."

2023-06-01 STL Clarify STL table B - IT spec notes on Tires

#34187 from Austin Hilliard · Rule change · TB 23-06 (2023-05 Fastrack)

In STL Spec Lines, Table B: Alternate Vehicle and Engine Allowances, change Notes as follows:
ITA-spec and ITS-spec RX7: "Must completely conform to ITCS specifications. Tires must conform to 9.1.4, Tires & Wheels. Tires
must also conform to 9.1.4.2.Tires."
ITS, ITA, ITB, or ITC vehicles (1985- ): "Must completely conform to ITCS specifications. Tires must conform to 9.1.4, Tires &
Wheels. Tires must also conform to 9.1.4.2.Tires."

2024-01-01 STL Alternate Carburetor Request for 79-85 RX7 12a

#35181 from Dan Sheppard · Rule change · TB 24-01 (2024-01 Fastrack)

In STL Table B: Alternate Vehicle and Engine Allowances, Mazda RX-7 12A (79-85), change Notes as follows:
"Street Porting of the engine only. Bridge porting, peripheral porting, and eyelash porting are prohibited. Contact SCCA National
Office for details of Street porting. Stock Nikki 4 bbl carburetor on a stock manifold only. or auto-type 2 bbl w/42mm choke(s) on
a “dual-y” manifold. Allow the standard removal of emissions related components, and allow air and fuel jets to be corrected.
Modification of the water jacket in the area of the spark plug for cooling purposes is permitted."

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

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

In GCR, Section 9.1.4.M.16., change as follows:
"Power steering may be modified in any of the following ways:
a. disconnected , pump, belt, pulley, and hoses may be removed. Hoses may also be looped. Steering rack or box may be
modified internally to work without pump.
b. an OEM manual steering rack for that model may be fitted
c. an electric power steering pump may be fitted
d. an OEM electric-assisted steering system may be used or any column mounted electric steering assist may be used
e. an OEM hydraulic-assisted steering system may be used"

2024-02-01 STL BOP Adjustments

#35112 from Super Touring Committee · Rule change · TB 24-02 (2024-01 Fastrack)

In GCR, 9.1.4.H.1., change as follows:
"Minimum weights for cars with normally aspirated piston engines will be determined by 1.35 lbs/cc displacement for
the installed engine (see the following table). Displacement is the factory displacement for the installed engine. For the
purpose of weight assignment, engine displacement will be rounded to the nearest 50cc (e.g., 2176cc = 2200cc and
2175cc = 2150cc)."
In GCR, 9.1.4.H.1., change Minimum Weight on Chart as follows:
Factory Engine Displacement 1900: "Effective 3-1-24: 2565 2540"
Factory Engine Displacement 1950: "Effective 3-1-24: 2633 2583"

2024-02-01 STL Mazda 12A

#35320 from Super Touring Committee · Rule change · TB 24-02 (2024-02 Fastrack)

In STL Spec Lines, Table A, Mazda 12A, change Notes as follows:
"The 5th and 6th intake port actuators and valves may be removed or disabled."

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

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

In GCR, Section 9.1.4.M.18., change as follows:
"18. Allow alternate front wheel front hubs, Mazda Motorsports Development Part #0000-04-5HUB-S1, for the 90-05 Mazda
Miata: Mazda Motorsports Development Part #0000-04-5HUB-S1."

2025-05-01 STL E&O: SMX Allowance in STL

#37945 from Greg Amy · Rule change · TB 25-05 (2025-05 Fastrack)

In STL Spec Lines, Table B, Mazda Spec MX5 Challenge, change as follows:
Minimum Weight: "2500 See 9.1.7.1."
Notes: "Mazda MX5 Challenge car must utilize the following components: Roush CNC cylinder head 0000-01-5300,Mahle
standard or +0.005 0000-01-5310, OEM camshaft, 11:1 compression ratio, header 0000-06-5407-NC, exhaust 0000-06-5427-NC,
cold air intake 0000- 06-5150-KT, ECU flash 0000-01-5379, Pagid front brake pads 0000-03-5104-SP or endurance pads 0000-03-
5104-EN, Pagid rear brake pads 0000-03-5114-SP or endurance pads 0000-03-5114-EN, Penske front shock 0000-04-5291-SA,
Penske rear shock 0000-04-5292-SA, Penske rear mount kit 0000-04-5358, Front mount kit 0000-04-5359, Front offset bushing
0000-04-5407-NC, Eibach front springs 0000-04-9700-08, Eibach rear springs 0000-04-9400-07, Eibach helper springs 0000-04-

Applies to Mazda MX-5 on this page: Cam Ebben_No_TX, David Palfenier, Austin Hill, James Ebben, Cam Ebben, Gavin Wardle, Bryan Heitman, Joe Ebben, Will Lucas, Reid Sweeney, Camden Risch, Rocco Pasquarella, Michael Borden, Javier Sanchez

2025-08-01 STL Lotus Weight Reduction

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

In 9.1.2. GT2/ST Spec Lines, Lotus Evora GT4, change Weight as follows:
"2750 2700"
In STU Table B: Alternate Vehicle and Engine Allowances, change Weight as follows:
Lotus Elise Cup R: "2300 2250"
Lotus Elise SC/ Lotus Exige SC: "2300 2550
2500 2450"

2026-01-01 STL Weight adjustment for STL

#39579 from Super Touring Committee · Rule change · TB 26-01 (2026-01 Fastrack)

In GCR, Section 9.1.4.2.H.1. change Minimum Weight on chart as follows:

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

2026-04-01 STL Classifications

#39885 from Jesse Prather · Rule change · TB 26-04 (2026-04 Fastrack)

In STL, Table A: Alternate Vehicle and Engine Requirements, add the following:
Model: "Mazda BP 1.6"
Maximum Displacement: "1600cc"
Minimum Weight: "2160"